CSY/reowolf Changeset - 11fd959b348a · Centrum Wiskunde & Informatica (CWI)

Changeset - 11fd959b348a

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Max Henger - 3 years ago 2022-03-04 19:21:00
henger@cwi.nl

fix: refactor 1.2.5

8 files changed:

docs/runtime/sync.md

145

src/protocol/eval/executor.rs

src/protocol/parser/pass_rewriting.rs

src/protocol/parser/pass_validation_linking.rs

src/protocol/parser/type_table.rs

src/runtime/scheduler.rs

src/runtime2/communication.rs

src/runtime2/component/component_context.rs

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docs/runtime/sync.md

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 # Synchronous Communication
+# Synchronous Communication and Component Orchestration
 ##
@@ \ No newline at end of file @@
 ## Introduction
 The Reowolf runtime consists of a system that allows multiple components to run within their own thread of execution. These components are able to exchange messages with one another. Components are capable of creating other components, and of creating channels. We may visualise the runtime as a cloud of all kinds of components, connected by the communication channels between them, hence a kind of communication graph.
 With this version of the runtime there were several main drivers. For performance reasons we want:
 - As little centralized information as possible (because centralization of information implies synchronization to access it).
 - As much parallelism as possible (when information *must* be exchanged, then make sure as little components are affected as possible).
 To keep the complexity of the runtime to a reasonable minimum, the following requirements have to be met as well:
 - A component may terminate, therefore potentially not being able to participate in synchronous communication or receive messages. Experimentation showed that the system that ensures that termination is broadcast to all peers should be kept simple (earlier systems depended on a state-machine with assumptions about the order in which messages were exchanged, which greatly complicates the messaging subsystem of the runtime).
 - Messages should arrive in order (with some exceptions). As we'll see later in this document we have different types of messages. Reasoning about a component's operational state becomes much simpler if we can assume that the transmission of messages between components is ordered.
 As we will see there are several types of messages that can be exchanged. Among them we have:
 - Data messages: these messages contain the data that is "transmitted from and to PDL code". For each `put` a data message is annotated by the runtime and sent along to the receiving component, which will then hopefully retrieve the data with a `get`. These messages are conceptually sent over channels.
 - Sync messages: these messages are sent between components to communicate their consensus-state. These messages are not necessarily associated with channels.
 - Control messages: these messages are sent between components to ensure that the entire runtime is reliably facilitating data exchange. That is: they ensure that the language is working as intended. As an example: sending a port to a different component requires a bit of bookkeeping to ensure that all involved components are aware of the port exchange.
 The remainder of this document tries to describe the various technical aspects of synchronous communication and component orchestration.
 ## Brief Description of Schedulers
 Each component conceptually has its own thread of execution. It is executing a program with at any given point in time a particular memory state. In reality there are a limited number of threads that execute components. Making sure that components are scheduled correctly is based on the fact that components are generally executing programs that are blocked at some point: a message needs to be received, or a port is blocked so we cannot send any information. At that point a component is considered "sleeping". Should another component, scheduled on a particular thread, send a message to this sleeping component, then it is "woken up" by putting it into the execution queue.
 The job of the scheduler is then to: execute a component scheduled for execution, wait until a component is scheduled, or shut down in case there are no more components to execute.
 The details of the execution queue (currently rather simplistically implemented) is not of interest. What is of interest is that a component can only be scheduled once.
 ## Creation of Channels
 Within PDL code it is possible to create new channels. And so a component will always (that is to say: for now) create both endpoints of the channel, hence own both endpoints of the channel upon creation. Identifiers for these ports are generated locally (we don't want to resolve to having to synchronize on some kind of global port ID counter).
 As these IDs are generated locally there is no real technical challenge, but note that ports at different components may have the same port ID.
 ## Creation of Components
 Within PDL code it is possible to create components. Upon their creation they can be given endpoints of channels. Hence at component creation we are changing the configuration of the communication graph. All of the relevant components need to be informed about the port changing ownership.
 Here we run into a plethora of problems. The other endpoint might have been given away to another created component. The other endpoint may have already been used in communication, such that we already have messages underway for the port we're trying to give to a newly created component. We may have that the local port ID assigned by the creating component is not the same as the local port ID that the newly created component may want to assign to it. We may have that this port has been passed along multiple times already, etc.
 We cannot help that messages have already arrived, or are in transit, for the transferred port. But we can make some assumptions that simplify the transfer of ports. As a first one, we have that the creating component decides when the created component is scheduled for execution. We'll choose not to execute it initially, such that we can be sure that it will not send messages over its ports the moment is created. To further simplify the problem, we have assumed that messages arrive in order. So although messages might still be underway for the transferred ports, if we ask the sender to stop sending, and the sender blocks the port and acknowledges that it has received this command. Then the moment the creator receives the acknowledgement it is certain that it has received all messages intended for the transferred ports. We'll also disallow the creation of components during synchronous interactions.
 And so here we have our first control protocol. If a port is transferred then we might have:
 . That the peer port is transferred to the new component as well. All is fine and we can take care of the exchange immediately.
 . That the peer port stays with the creating component. Here all is fine as well, everything is running in a single thread of execution so we diligently do our bookkeeping on the data associated with the port and the channel and we can transfer the port.
 . The peer port is already owned by a different component. Here we need to have a slightly more complicated protocol
 In this last case we take the following actions, `C` for creating component, `N` for newly created component, and `P` for the peer component that holds the other port of the same channel.
 . `C` transfers the port to the newly created component `N`, and ask it to come up with a new ID for that port. The port had an ID that was decided by its old owner `C`, and now has one that is agreeable with component `N`.
 . `C` sends a control message `PeerChangeBlockPort` to the peer `P`.
 . `P` receives the `PeerChangeBlockPort` message. It causes the peer port to be temporarily blocked. `P` may still continue executing its code, but the moment it wishes to send something over this port it is forced to block its execution. In response `P` sends an `Acknowledge` message back to `C`.
 . `C` waits for the `Acknowledge` message of `C`. Since the `Acknowledge` message was sent after the last data message that `P` sent to the port under consideration, and because `P` has blocked that port, we are certain that we received all messages. We transfer these messages to `N`.
 . Note that there may be multiple ports being transferred from `C` to `N`, each with a potentially different peer. And so here `C` waits until steps 2 through 4 are completed for all of the transferred ports.
 . Once `C` has received all of the `Acknowledge` messages it was waiting for, it will send a `PeerChangeUnblockPort` message to each peer `P`. This message contains the new port ID, such that `P` can unblock its port, and continue sending messages over this channel, but now correctly arriving at `N`. Additionally, `C` will now schedule the new component `N`.
 There is a bit of extra overhead here with the `PeerChangeBlockPort` -> `Acknowledge` -> `PeerChangeUnblockPort` sequence with respect to other possible schemes. But this one allows `P` to continue executing its code as long as it does not use its blocked port. It also ensures that messages arrive in order: they're all collected by `C`, given to `N`, and only then may `P` continue creating messages to `N`, hence arriving after the earlier messages have been handed off to `N`.
 As we'll later introduce, ports can end up being closed. When a port is closed the above procedure is not initiated. A port cannot be reopened, and once a port is closed its peer is also notified that the channel cannot be used anymore. As such, it is not needed (and perhaps impossible, if the memory backing the peer component has already been freed) to notify that the port will change peer.
 ## Managing the Lifetime of Components
 Components are created by other components or by the API. Note that the API may for intents and purposes be viewed as a component. It may own and create channels, and it may create components. Component start, like a function, executing at the top of their program listing and may end in two ways. Either they encounter an unrecoverable error, or they neatly reach the end of their execution.
 In either case we want to free up the memory that was occupied by the component during its execution. And we want to make sure that any kind of pending message/action is correctly handled. Apart from that the component contains somekind of message inbox, whose memory is associated with that component. Hence we want to make sure that all peers are aware that they're no longer able to send messages to a terminated component.
 A small interlude before we continue: trying to take care of unrecoverable errors that occur during a sync round by incorporating the appropriate logic into the consensus algorithm proved to be rather hard. It caused a large increase in the number of states a component could be in, and as a result made the code much harder to reason about. That is: not so much communicating that an error had ocurred (that needs to occur in every synchronous algorithm), but keeping track of which messages can be sent to which component during the consensus algorithm.
 For this reason there are two systems that make sure that components stay alive as long as needed. Firstly components will have a reference counter. For simplicity the component also holds a reference to itself. The component will remove this self-reference when it terminates. Each channel causes two components to also hold references to eachother. *If* a consensus algorithm is implemented such that a central components ends up communicating to all participating parties (using channels or not using channels), then we can make sure that it can reach all participating components by incrementing their reference counts (note that this is not yet properly implemented in the runtime).
 Through this mechanism the consensus algorithm can be greatly simplified. If a component encounters a critical error and is already participated in a sync round, then it can notify the other participants, but remain reachable to all other components until the round ends (and the reference counts are decreased again).
 A second system is needed to ensure that a component actually exits (because all the peers hold a reference, and we need all of those references to drop to 0 to truly remove the component from the runtime). And so when a component exits it will send `ClosePort` messages to all of its peers. These peers will `Acknowledge` those messages and close the respective ports, meaning that they will no longer allow sending messages over those ports, that will be a fatal error. However, messages that were sent to the exiting component before receiving the `ClosePort` message might still be underway. And so the terminating component will wait for all of the `Acknowledge` messages for all of its channels such that it knows that it has received all data messages. The component will respond to these intermediate messages with a `DataMessageFailed` message, meaning that the message has been received the moment the component was already terminated, hence the sender should consider this a failed message transmission.
 Bringing these systems together: apart from data messages there might still be control messages in transit, or the exiting component might still have some control/sync work to do. And so we need to modify something we said earlier: instead of a component removing its self-reference the moment it terminates, we do this the moment we have received all the `Acknowledge` messages we were expecting. This way if a component is busy creating another component, we're certain that the appropriate protocols are observed. So:
 Concluding everything described above, two separate mechanisms will act in conjunction:
 - A. The exiting component `E` waiting until it has finished notifying all peers `P` of its termination:
 . Component `E` sends a `ClosePort` message to each peer `P` for each of the shared channels (except when the port is already closed because `P` is also in the process of shutting down).
 . The peer `P` receives the `ClosePort` message and closes the port as a result. This is a change of port state that will cause any subsequent `put` operations on that port to become a fatal error for component `P`. In response the peer `P` sends an `Acknowledge` message to component `E`, unless component `P` exited itself (that is: sending a `ClosePort` message to `E` before the `ClosePort` message from `P` arrived). After closing the port the component `P` will remove the reference to `E`.
 . Component `E` waits until all of its pending control operations are finished (i.e. waiting for the `Acknowledge` messages following `ClosePort` messages, `PeerChangeBlockPort` messages, etc.). Once all of these are finished, note that we can no longer participate in any future control actions: component `E` will not create channels/components itself. Since all of its ports are closed, the peers `P` will also not send any data or control messages.
 . Component `E` now checks its inbox for any remaining messages. It will respond to any data messages that arrived after `E` sending `ClosePort` and before `E` receiving `Acknowledge` with a `DataMessageFailed` message (except for ports that were closed before the `Acknowledge`). Then it removes the reference to itself, therefore decrementing the reference counter for the component by 1.
 - B. The reference counting mechanism. Any sync round the exiting component `E` is participating in will conceptually hold a reference to `E`. The component `E` will always respond to sync messages as if it were alive (albeit trying to indicate to everyone that it is actually exiting). The component that removes the last reference to the component `E` (which may be `E` itself, but also a peer `P`) will truly remove the associated memory from the runtime.
 **Note**: We did not consider machine termination. That is to say: once we reach the runtime maturity where communication occurs over different machines, then we have to consider that machines encounter fatal errors. However these can only be resolved by embedding the possibility of failure inside the protocol over which these machines communicate.
 ## Sending Data Messages
 So far we've discussed the following properties associated with sending data messages:
 . Port IDs are decided locally. So a peer may have an ID that is outdated for the intended recipient.
 . Ports can move from owner to owner. So a peer might have a component ID that is outdated for the intended recipient.
 . Ports may be closed.
 . Message intended for specific ports may end up at an intermediate component that is passing that message along.
 However, there are some properties that we can take advantage of:
 . When a component sends a message, it knows for certain what its own component ID and port ID is. So a transmitting port always sends the correct source component/port ID.
 . When a component receives a message, it knows for certain what its own component ID and port ID is. So once a receiving port receives a properly annotated message from a transmitted port, the receiving end can be certain about the component IDs and port IDs that make up the channel.
 Note that although the message transmitter may not be certain about its final recipient, the components along the way *are* aware of the routing that is necessary to make the message arrive at the intended target. Combing back to the case where we have a creator `C`, new component `N` and peer `P`. Then `P` will send a message intended for `N`, but arriving at `C`. Here `C` can change the target port and component to `N` (as it is in the process of transferring that port, so knows both its original and new port ID). Once the message arrives and is accepted by the recipient then it is certain about the component and port IDs.
 ## Sending Sync Messages
 Sync messages have the purpose of making sure that consensus is reached about the interactions that took place in all of the participating components' sync blocks. The previous runtime featured speculative execution and a branching execution model: a component could exhibit multiple behaviours, and at the end all components decide which combination of local behaviours constitute a satisfying single global behaviour (if one exists at all). Without speculative execution the model can be a lot simpler.
 We'll only shortly discuss the mechanisms that are present in the synchronization algorithm. A component has a local counter, that is reset for each synchronous interaction, that is used when transmitting data messages. Such a message will be annotated with the counter at `N`, after which the component sends the next message with annotation `N+1`. At the same time the component will keep track of a local mapping from port ID to port annotation, we'll call this the port mapping. Likewise, when a component receives a data message it will assign the received annotation in its own port mapping. If two components assign the same annotation to the ports that constitute a channel, then there is an agreeable interaction there.
 And so at the end of the synchronous round a component will somehow broadcast its port mapping. Note from the discussion above that a transmitting port's annotation is only associated with that transmitting port, since a transmitting port can only truly ever know its own component/port ID. While the receiving port's annotation knows about the peer's component/port ID as well. And so a component can broadcast `(component ID, port ID, mapping)` for each of its transmitting ports, while it can broadcast `(own component ID, own port ID, peer component ID, peer port ID, mapping)` for each receiving port. Then a recipient of these mappings can match them up and make sure that the mappings agree.
 Note that this broadcasting of synchronous messages is essentially a component-to-component operation. However these messages must still be sent over ports anyway (and any port that was used to transmit messages to a particular receiving component will do). There are two reasons:
 . The sync message may need to be rerouted (e.g. a sender quickly fires both a data message and a subsequent sync message while the receiving port is being transferred to a new component), but needs to arrive at the same target as the data message. This is essentially restating that a transmitter never knows about the component ID of the recipient.
 . The sync message must not be taken into account by the recipient if it has not accepted any messages from the sender yet. Ofcourse this can be achieved in various ways but a simple way to achieve this is to send the sync message over ports.
 ## Annotating Data Messages
 These port mappings are also sent along when sending data messages. We will not go into details but here the mapping makes sure that messages arrive in the right order, and certain kinds of deadlock or inconsistent protocol behaviour may be detected. This port mapping is checked for consistency by the recipient and, when consistent, the target port is updated with its new mapping.
 As we'll send along this mapping we will only consider the ports that are shared between the two components. But in the most general case the transmitting ports of the component do not have knowledge about the peer component. And so the sent port mapping will have to contain the annotation for *all* transmitting ports. Receiving port mappings only have to be sent along if they received a message, and here we can indeed apply filtering. Likewise, if the recipient of a port mapping has not yet received anything on its receiving port, then it cannot be sure about the identity of the sender.
 This leads to problems both for ensuring the correct ordering of the messages. For finding consensus it is not. Suppose that a port `a` sends a message to a port `b`. Port `b` does not accept it. Upon trying to find consensus we see that `a` will submit an entry in its port mapping, and `b` does not submit anything at all. Hence no solution can be found, as desired.
 For the message ordering we require from the receiver that it confirms that, for all of the shared channels, it has the same mapping as the sender sends along. Suppose a component `A` has ports `a_put` and `b_put`, while a component `B` has ports `a_get` and `b_get` (where `a_put -> a_get` and `b_put -> b_get`). Suppose component `A` sends on `a_put` and `b_put` consecutively. And component `B` only receives from `b_get`. Then since `a_get` did not receive from `a_put` (hence did not learn that component/port ID pair of `a_put` is associated with `a_get`), the component `B` cannot figure out that `a_get` should precede a `b_get`. Likewise component `A` has no way to know that `a_put` and `b_put` are sending to the same component, hence it cannot indicate to component `B` that `a_get` should precede `b_get`.
 There are some simple assumptions we can make that makes the problem a little bit easier to think about. Suppose again `a_put -> a_get` and `b_put -> b_get`. Suppose `a_put` is used first, where we send along the mapping of `a_put` and `b_put`. Then we send along `b_put`, again sending along the mapping. Then it is possible for the receiving component to accept the wrong message first (e.g. `b_get`, therefore learning about `b`), but it will be impossible to get from `a_get` later, since that one requires `b_put` (of which we learned that it matches `b_get`) to not have sent any messages.
 Without adding any extra overhead (e.g. some kind of discovery round per synchronous interaction), we can take three approaches:
 . We simply don't care. It is impossible for a round where messages are received out of order to complete. Hence we temporarily allow a component to take the wrong actions, therefore wasting some CPU time, and to crash/error afterward.
 . We remove the entire concept of ordering of channels at a single component. Channels are always independent entities. This way we truly do not have to care. All we care about is that the messages that have been sent over a channel arrive at the other side.
 . We slightly modify the algorithm to detect these problems. This can be done in reasonable fashion, albeit a bit "hacky". For each channel there is a slot to receive messages. Messages wait there until the receiver performs a `get` in the PDL code. So far we've only considered learning about the component/port IDs that constitute a channel the moment they're received with a `get`. The algorithm could be changed to already learn about the peer component/port ID the moment the message arrives in the slot.
 We'll go with the last option in the current implementation. We return to the problematic example above. Note that messages between components are sent in ordered fashion, and `a_put` happens before `b_put`. Then component `B` will first learn that `a_put` is the peer of `a_get`, then it performs the first `get` on the message from `b_put` to `b_get`. This message is annotated with a port mapping that `a_put` has been used before. We're now able to detect at component `B` that we cannot accept `b_get` before `a_get`.
 Concluding:
 - Every data message that is transmitted needs to contain the port mapping of all `put`ting ports (annotating them appropriately if they have not yet been used). We also need to include the port mapping of all `get`ting ports that have a pending/received message. The port mapping for `put`ting ports will only include their own ID, the port mapping for `get`ting ports will include the IDs of their peer as well.
 - Every arriving data message will immediately be used to identify the sender as the peer of the corresponding `get`ter port. Since messages between components arrive in order this allows us to detect when the `put`s are in a different order at the sender as the `get`s at the receiver.
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src/protocol/eval/executor.rs

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 use std::collections::VecDeque;
 use super::value::*;
 use super::store::*;
 use super::error::*;
 use crate::protocol::*;
 use crate::protocol::ast::*;
 use crate::protocol::type_table::*;
 macro_rules! debug_enabled { () => { false }; }
 macro_rules! debug_log {
     ($format:literal) => {
         enabled_debug_print!(false, "exec", $format);
     };
     ($format:literal, $($args:expr),*) => {
         enabled_debug_print!(false, "exec", $format, $($args),*);
     };
+}
 #[derive(Debug, Clone)]
 pub(crate) enum ExprInstruction {
     EvalExpr(ExpressionId),
     PushValToFront,
+}
 #[derive(Debug, Clone)]
 pub(crate) struct Frame {
     pub(crate) definition: ProcedureDefinitionId,
     pub(crate) monomorph_type_id: TypeId,
     pub(crate) monomorph_index: usize,
     pub(crate) position: StatementId,
     pub(crate) expr_stack: VecDeque<ExprInstruction>, // hack for expression evaluation, evaluated by popping from back
     pub(crate) expr_values: VecDeque<Value>, // hack for expression results, evaluated by popping from front/back
     pub(crate) max_stack_size: u32,
+}
 impl Frame {
     /// Creates a new execution frame. Does not modify the stack in any way.
-    pub fn new(heap: &Heap, definition_id: ProcedureDefinitionId, monomorph_type_id: TypeId, monomorph_index: u32) -> Self {
+    pub fn new(heap: &Heap, definition_id: ProcedureDefinitionId, _monomorph_type_id: TypeId, monomorph_index: u32) -> Self {
         let definition = &heap[definition_id];
         let outer_scope_id = definition.scope;
         let first_statement_id = definition.body;
         // Another not-so-pretty thing that has to be replaced somewhere in the
         // future...
         fn determine_max_stack_size(heap: &Heap, scope_id: ScopeId, max_size: &mut u32) {
             let scope = &heap[scope_id];
             // Check current block
             let cur_size = scope.next_unique_id_in_scope as u32;
             if cur_size > *max_size { *max_size = cur_size; }
             // And child blocks
             for child_scope in &scope.nested {
                 determine_max_stack_size(heap, *child_scope, max_size);
+            }
+        }
         let mut max_stack_size = 0;
         determine_max_stack_size(heap, outer_scope_id, &mut max_stack_size);
         Frame{
             definition: definition_id,
             monomorph_type_id,
             monomorph_index: monomorph_index as usize,
             position: first_statement_id.upcast(),
             expr_stack: VecDeque::with_capacity(128),
             expr_values: VecDeque::with_capacity(128),
             max_stack_size,
+        }
+    }
     /// Prepares a single expression for execution. This involves walking the
     /// expression tree and putting them in the `expr_stack` such that
     /// continuously popping from its back will evaluate the expression. The
     /// results of each expression will be stored by pushing onto `expr_values`.
     pub fn prepare_single_expression(&mut self, heap: &Heap, expr_id: ExpressionId) {
         debug_assert!(self.expr_stack.is_empty());
         self.expr_values.clear(); // May not be empty if last expression result(s) were discarded
         self.serialize_expression(heap, expr_id);
+    }
     /// Prepares multiple expressions for execution (i.e. evaluating all
     /// function arguments or all elements of an array/union literal). Per
     /// expression this works the same as `prepare_single_expression`. However
     /// after each expression is evaluated we insert a `PushValToFront`
     /// instruction
     pub fn prepare_multiple_expressions(&mut self, heap: &Heap, expr_ids: &[ExpressionId]) {
         debug_assert!(self.expr_stack.is_empty());
         self.expr_values.clear();
         for expr_id in expr_ids {
             self.expr_stack.push_back(ExprInstruction::PushValToFront);
             self.serialize_expression(heap, *expr_id);
+        }
+    }
     /// Performs depth-first serialization of expression tree. Let's not care
     /// about performance for a temporary runtime implementation
     fn serialize_expression(&mut self, heap: &Heap, id: ExpressionId) {
         self.expr_stack.push_back(ExprInstruction::EvalExpr(id));
         match &heap[id] {
             Expression::Assignment(expr) => {
                 self.serialize_expression(heap, expr.left);
                 self.serialize_expression(heap, expr.right);
             },
             Expression::Binding(expr) => {
                 self.serialize_expression(heap, expr.bound_to);
                 self.serialize_expression(heap, expr.bound_from);
             },
             Expression::Conditional(expr) => {
                 self.serialize_expression(heap, expr.test);
             },
             Expression::Binary(expr) => {
                 self.serialize_expression(heap, expr.left);
                 self.serialize_expression(heap, expr.right);
             },
             Expression::Unary(expr) => {
                 self.serialize_expression(heap, expr.expression);
             },
             Expression::Indexing(expr) => {
                 self.serialize_expression(heap, expr.index);
                 self.serialize_expression(heap, expr.subject);
             },
             Expression::Slicing(expr) => {
                 self.serialize_expression(heap, expr.from_index);
                 self.serialize_expression(heap, expr.to_index);
                 self.serialize_expression(heap, expr.subject);
             },
             Expression::Select(expr) => {
                 self.serialize_expression(heap, expr.subject);
             },
             Expression::Literal(expr) => {
                 // Here we only care about literals that have subexpressions
                 match &expr.value {
                     Literal::Null | Literal::True | Literal::False |
                     Literal::Character(_) | Literal::String(_) |
                     Literal::Integer(_) | Literal::Enum(_) => {
                         // No subexpressions
                     },
                     Literal::Struct(literal) => {
                         // Note: fields expressions are evaluated in programmer-
                         // specified order. But struct construction expects them
                         // in type-defined order. I might want to come back to
                         // this.
                         let mut _num_pushed = 0;
                         for want_field_idx in 0..literal.fields.len() {
                             for field in &literal.fields {
                                 if field.field_idx == want_field_idx {
                                     _num_pushed += 1;
                                     self.expr_stack.push_back(ExprInstruction::PushValToFront);
                                     self.serialize_expression(heap, field.value);
+                                }
+                            }
+                        }
                         debug_assert_eq!(_num_pushed, literal.fields.len())
                     },
                     Literal::Union(literal) => {
                         for value_expr_id in &literal.values {
                             self.expr_stack.push_back(ExprInstruction::PushValToFront);
                             self.serialize_expression(heap, *value_expr_id);
+                        }
                     },
                     Literal::Array(value_expr_ids) => {
                         for value_expr_id in value_expr_ids {
                             self.expr_stack.push_back(ExprInstruction::PushValToFront);
                             self.serialize_expression(heap, *value_expr_id);
+                        }
                     },
                     Literal::Tuple(value_expr_ids) => {
                         for value_expr_id in value_expr_ids {
                             self.expr_stack.push_back(ExprInstruction::PushValToFront);
                             self.serialize_expression(heap, *value_expr_id);
+                        }
+                    }
+                }
             },
             Expression::Cast(expr) => {
                 self.serialize_expression(heap, expr.subject);
+            }
             Expression::Call(expr) => {
                 for arg_expr_id in &expr.arguments {
                     self.expr_stack.push_back(ExprInstruction::PushValToFront);
                     self.serialize_expression(heap, *arg_expr_id);
+                }
             },
             Expression::Variable(_expr) => {
                 // No subexpressions
+            }
+        }
+    }
+}
 pub type EvalResult = Result<EvalContinuation, EvalError>;
 #[derive(Debug)]
 pub enum EvalContinuation {
     // Returned in both sync and non-sync modes
     Stepping,
     // Returned only in sync mode
     BranchInconsistent,
     SyncBlockEnd,
     NewFork,
     BlockFires(PortId),
     BlockGet(PortId),
     Put(PortId, ValueGroup),
     SelectStart(u32, u32), // (num_cases, num_ports_total)
     SelectRegisterPort(u32, u32, PortId), // (case_index, port_index_in_case, port_id)
     SelectWait, // wait until select can continue
     // Returned only in non-sync mode
     ComponentTerminated,
     SyncBlockStart,
     NewComponent(ProcedureDefinitionId, TypeId, ValueGroup),
     NewChannel,
+}
 // Note: cloning is fine, methinks. cloning all values and the heap regions then
 // we end up with valid "pointers" to heap regions.
 #[derive(Debug, Clone)]
 pub struct Prompt {
     pub(crate) frames: Vec<Frame>,
     pub(crate) store: Store,
+}
 impl Prompt {
     pub fn new(types: &TypeTable, heap: &Heap, def: ProcedureDefinitionId, type_id: TypeId, args: ValueGroup) -> Self {
         let mut prompt = Self{
             frames: Vec::new(),
             store: Store::new(),
         };
         // Maybe do typechecking in the future?
         let monomorph_index = types.get_monomorph(type_id).variant.as_procedure().monomorph_index;
         let new_frame = Frame::new(heap, def, type_id, monomorph_index);
         let max_stack_size = new_frame.max_stack_size;
         prompt.frames.push(new_frame);
         args.into_store(&mut prompt.store);
         prompt.store.reserve_stack(max_stack_size);
         prompt
+    }
     /// Big 'ol function right here. Didn't want to break it up unnecessarily.
     /// It consists of, in sequence: executing any expressions that should be
     /// executed before the next statement can be evaluated, then a section that
     /// performs debug printing, and finally a section that takes the next
     /// statement and executes it. If the statement requires any expressions to
     /// be evaluated, then they will be added such that the next time `step` is
     /// called, all of these expressions are indeed evaluated.
     pub(crate) fn step(&mut self, types: &TypeTable, heap: &Heap, modules: &[Module], ctx: &mut impl RunContext) -> EvalResult {
         // Helper function to transfer multiple values from the expression value
         // array into a heap region (e.g. constructing arrays or structs).
         fn transfer_expression_values_front_into_heap(cur_frame: &mut Frame, store: &mut Store, num_values: usize) -> HeapPos {
             let heap_pos = store.alloc_heap();
             // Do the transformation first (because Rust...)
             for val_idx in 0..num_values {
                 cur_frame.expr_values[val_idx] = store.read_take_ownership(cur_frame.expr_values[val_idx].clone());
+            }
             // And now transfer to the heap region
             let values = &mut store.heap_regions[heap_pos as usize].values;
             debug_assert!(values.is_empty());
             values.reserve(num_values);
             for _ in 0..num_values {
                 values.push(cur_frame.expr_values.pop_front().unwrap());
+            }
             heap_pos
+        }
         // Helper function to make sure that an index into an aray is valid.
         fn array_inclusive_index_is_invalid(store: &Store, array_heap_pos: u32, idx: i64) -> bool {
             let array_len = store.heap_regions[array_heap_pos as usize].values.len();
             return idx < 0 || idx >= array_len as i64;
+        }
         fn array_exclusive_index_is_invalid(store: &Store, array_heap_pos: u32, idx: i64) -> bool {
             let array_len = store.heap_regions[array_heap_pos as usize].values.len();
             return idx < 0 || idx > array_len as i64;
+        }
         fn construct_array_error(prompt: &Prompt, modules: &[Module], heap: &Heap, expr_id: ExpressionId, heap_pos: u32, idx: i64) -> EvalError {
             let array_len = prompt.store.heap_regions[heap_pos as usize].values.len();
             return EvalError::new_error_at_expr(
                 prompt, modules, heap, expr_id,
                 format!("index {} is out of bounds: array length is {}", idx, array_len)
+            )
+        }
         // Checking if we're at the end of execution
         let cur_frame = self.frames.last_mut().unwrap();
         if cur_frame.position.is_invalid() {
             if heap[cur_frame.definition].kind == ProcedureKind::Function {
                 todo!("End of function without return, return an evaluation error");
+            }
             return Ok(EvalContinuation::ComponentTerminated);
+        }
         debug_log!("Taking step in '{}'", heap[cur_frame.definition].identifier.value.as_str());
         // Execute all pending expressions
         while !cur_frame.expr_stack.is_empty() {
             let next = cur_frame.expr_stack.pop_back().unwrap();
             debug_log!("Expr stack: {:?}", next);
             match next {
                 ExprInstruction::PushValToFront => {
                     cur_frame.expr_values.rotate_right(1);
                 },
                 ExprInstruction::EvalExpr(expr_id) => {
                     let expr = &heap[expr_id];
                     match expr {
                         Expression::Assignment(expr) => {
                             let to = cur_frame.expr_values.pop_back().unwrap().as_ref();
                             let rhs = cur_frame.expr_values.pop_back().unwrap();
                             // Note: although not pretty, the assignment operator takes ownership
                             // of the right-hand side value when possible. So we do not drop the
                             // rhs's optionally owned heap data.
                             let rhs = self.store.read_take_ownership(rhs);
                             apply_assignment_operator(&mut self.store, to, expr.operation, rhs);
                         },
                         Expression::Binding(_expr) => {
                             let bind_to = cur_frame.expr_values.pop_back().unwrap();
                             let bind_from = cur_frame.expr_values.pop_back().unwrap();
                             let bind_to_heap_pos = bind_to.get_heap_pos();
                             let bind_from_heap_pos = bind_from.get_heap_pos();
                             let result = apply_binding_operator(&mut self.store, bind_to, bind_from);
                             self.store.drop_value(bind_to_heap_pos);
                             self.store.drop_value(bind_from_heap_pos);
                             cur_frame.expr_values.push_back(Value::Bool(result));
                         },
                         Expression::Conditional(expr) => {
                             // Evaluate testing expression, then extend the
                             // expression stack with the appropriate expression
                             let test_result = cur_frame.expr_values.pop_back().unwrap().as_bool();
                             if test_result {
                                 cur_frame.serialize_expression(heap, expr.true_expression);
                             } else {
                                 cur_frame.serialize_expression(heap, expr.false_expression);
+                            }
                         },
                         Expression::Binary(expr) => {
                             let lhs = cur_frame.expr_values.pop_back().unwrap();
                             let rhs = cur_frame.expr_values.pop_back().unwrap();
                             let result = apply_binary_operator(&mut self.store, &lhs, expr.operation, &rhs);
                             cur_frame.expr_values.push_back(result);
                             self.store.drop_value(lhs.get_heap_pos());
                             self.store.drop_value(rhs.get_heap_pos());
                         },
                         Expression::Unary(expr) => {
                             let val = cur_frame.expr_values.pop_back().unwrap();
                             let result = apply_unary_operator(&mut self.store, expr.operation, &val);
                             cur_frame.expr_values.push_back(result);
                             self.store.drop_value(val.get_heap_pos());
                         },
                         Expression::Indexing(_expr) => {
                             // Evaluate index. Never heap allocated so we do
                             // not have to drop it.
                             let index = cur_frame.expr_values.pop_back().unwrap();
                             let index = self.store.maybe_read_ref(&index);
                             debug_assert!(index.is_integer());
                             let index = if index.is_signed_integer() {
                                 index.as_signed_integer() as i64
                             } else {
                                 index.as_unsigned_integer() as i64
                             };
                             let subject = cur_frame.expr_values.pop_back().unwrap();
                             let (deallocate_heap_pos, value_to_push) = match subject {
                                 Value::Ref(value_ref) => {
                                     // Our expression stack value is a reference to something that
                                     // exists in the normal stack/heap. We don't want to deallocate
                                     // this thing. Rather we want to return a reference to it.
                                     let subject = self.store.read_ref(value_ref);
                                     let subject_heap_pos = match subject {
                                         Value::String(v) => *v,
                                         Value::Array(v) => *v,
                                         Value::Message(v) => *v,
                                         _ => unreachable!(),
                                     };
                                     if array_inclusive_index_is_invalid(&self.store, subject_heap_pos, index) {
                                         return Err(construct_array_error(self, modules, heap, expr_id, subject_heap_pos, index));
+                                    }
                                     (None, Value::Ref(ValueId::Heap(subject_heap_pos, index as u32)))
                                 },
                                 _ => {
                                     // Our value lives on the expression stack, hence we need to
                                     // clone whatever we're referring to. Then drop the subject.
                                     let subject_heap_pos = match &subject {
                                         Value::String(v) => *v,
                                         Value::Array(v) => *v,
                                         Value::Message(v) => *v,
                                         _ => unreachable!(),
                                     };
                                     if array_inclusive_index_is_invalid(&self.store, subject_heap_pos, index) {
                                         return Err(construct_array_error(self, modules, heap, expr_id, subject_heap_pos, index));
+                                    }
                                     let subject_indexed = Value::Ref(ValueId::Heap(subject_heap_pos, index as u32));
                                     (Some(subject_heap_pos), self.store.clone_value(subject_indexed))
                                 },
                             };
                             cur_frame.expr_values.push_back(value_to_push);
                             self.store.drop_value(deallocate_heap_pos);
                         },
                         Expression::Slicing(expr) => {
                             // Evaluate indices
                             let from_index = cur_frame.expr_values.pop_back().unwrap();
                             let from_index = self.store.maybe_read_ref(&from_index);
                             let to_index = cur_frame.expr_values.pop_back().unwrap();
                             let to_index = self.store.maybe_read_ref(&to_index);
                             debug_assert!(from_index.is_integer() && to_index.is_integer());
                             let from_index = if from_index.is_signed_integer() {
                                 from_index.as_signed_integer()
                             } else {
                                 from_index.as_unsigned_integer() as i64
                             };
                             let to_index = if to_index.is_signed_integer() {
                                 to_index.as_signed_integer()
                             } else {
                                 to_index.as_unsigned_integer() as i64
                             };
                             // Dereference subject if needed
                             let subject = cur_frame.expr_values.pop_back().unwrap();
                             let deref_subject = self.store.maybe_read_ref(&subject);
                             // Slicing needs to produce a copy anyway (with the
                             // current evaluator implementation)
                             enum ValueKind{ Array, String, Message }
                             let (value_kind, array_heap_pos) = match deref_subject {
                                 Value::Array(v) => (ValueKind::Array, *v),
                                 Value::String(v) => (ValueKind::String, *v),
                                 Value::Message(v) => (ValueKind::Message, *v),
                                 _ => unreachable!()
                             };

src/protocol/parser/pass_rewriting.rs

➞

Show inline comments

 use crate::collections::*;
 use crate::protocol::*;
 use super::visitor::*;
 pub(crate) struct PassRewriting {
     current_scope: ScopeId,
     current_procedure_id: ProcedureDefinitionId,
     definition_buffer: ScopedBuffer<DefinitionId>,
     statement_buffer: ScopedBuffer<StatementId>,
     call_expr_buffer: ScopedBuffer<CallExpressionId>,
     expression_buffer: ScopedBuffer<ExpressionId>,
     scope_buffer: ScopedBuffer<ScopeId>,
+}
 impl PassRewriting {
     pub(crate) fn new() -> Self {
         Self{
             current_scope: ScopeId::new_invalid(),
             current_procedure_id: ProcedureDefinitionId::new_invalid(),
             definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             statement_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             call_expr_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             expression_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             scope_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
+        }
+    }
+}
 impl Visitor for PassRewriting {
     fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
         let module = ctx.module();
         debug_assert_eq!(module.phase, ModuleCompilationPhase::Typed);
         let root_id = module.root_id;
         let root = &ctx.heap[root_id];
         let definition_section = self.definition_buffer.start_section_initialized(&root.definitions);
         for definition_index in 0..definition_section.len() {
             let definition_id = definition_section[definition_index];
             self.visit_definition(ctx, definition_id)?;
+        }
         definition_section.forget();
         ctx.module_mut().phase = ModuleCompilationPhase::Rewritten;
         return Ok(())
+    }
     // --- Visiting procedures
     fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
         let definition = &ctx.heap[id];
         let body_id = definition.body;
         self.current_scope = definition.scope;
         self.current_procedure_id = id;
         return self.visit_block_stmt(ctx, body_id);
+    }
     // --- Visiting statements (that are not the select statement)
     fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
         let block_stmt = &ctx.heap[id];
         let stmt_section = self.statement_buffer.start_section_initialized(&block_stmt.statements);
         self.current_scope = block_stmt.scope;
         for stmt_idx in 0..stmt_section.len() {
             self.visit_stmt(ctx, stmt_section[stmt_idx])?;
+        }
         stmt_section.forget();
         return Ok(())
+    }
     fn visit_labeled_stmt(&mut self, ctx: &mut Ctx, id: LabeledStatementId) -> VisitorResult {
         let labeled_stmt = &ctx.heap[id];
         let body_id = labeled_stmt.body;
         return self.visit_stmt(ctx, body_id);
+    }
     fn visit_if_stmt(&mut self, ctx: &mut Ctx, id: IfStatementId) -> VisitorResult {
         let if_stmt = &ctx.heap[id];
         let true_case = if_stmt.true_case;
         let false_case = if_stmt.false_case;
         self.current_scope = true_case.scope;
         self.visit_stmt(ctx, true_case.body)?;
         if let Some(false_case) = false_case {
             self.current_scope = false_case.scope;
             self.visit_stmt(ctx, false_case.body)?;
+        }
         return Ok(())
+    }
     fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
         let while_stmt = &ctx.heap[id];
         let body_id = while_stmt.body;
         self.current_scope = while_stmt.scope;
         return self.visit_stmt(ctx, body_id);
+    }
     fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
         let sync_stmt = &ctx.heap[id];
         let body_id = sync_stmt.body;
         self.current_scope = sync_stmt.scope;
         return self.visit_stmt(ctx, body_id);
+    }
     // --- Visiting the select statement
     fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
         // Utility for the last stage of rewriting process. Note that caller
         // still needs to point the end of the if-statement to the end of the
         // replacement statement of the select statement.
         fn transform_select_case_code(
             ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId,
             select_id: SelectStatementId, case_index: usize,
             select_var_id: VariableId, select_var_type_id: TypeIdReference
         ) -> (IfStatementId, EndIfStatementId, ScopeId) {
             // Retrieve statement IDs associated with case
             let case = &ctx.heap[select_id].cases[case_index];
             let case_guard_id = case.guard;
             let case_body_id = case.body;
             let case_scope_id = case.scope;
             // Create the if-statement for the result of the select statement
             let compare_expr_id = create_ast_equality_comparison_expr(ctx, containing_procedure_id, select_var_id, select_var_type_id, case_index as u64);
             let true_case = IfStatementCase{
                 body: case_guard_id, // which is linked up to the body
                 scope: case_scope_id,
             };
             let (if_stmt_id, end_if_stmt_id) = create_ast_if_stmt(ctx, compare_expr_id.upcast(), true_case, None);
             // Link up body statement to end-if
             set_ast_statement_next(ctx, case_body_id, end_if_stmt_id.upcast());
             return (if_stmt_id, end_if_stmt_id, case_scope_id);
+        }
         // Precreate the block that will end up containing all of the
         // transformed statements. Also precreate the scope associated with it
         let (outer_block_id, outer_end_block_id, outer_scope_id) =
             create_ast_block_stmt(ctx, Vec::new());
         // The "select" and the "end select" statement will act like trampolines
         // that jump to the replacement block. So set the child/parent
         // relationship already.
         // --- for the statements
         let select_stmt = &mut ctx.heap[id];
         select_stmt.next = outer_block_id.upcast();
         let end_select_stmt_id = select_stmt.end_select;
         let select_stmt_relative_pos = select_stmt.relative_pos_in_parent;
         let outer_end_block_stmt = &mut ctx.heap[outer_end_block_id];
         outer_end_block_stmt.next = end_select_stmt_id.upcast();
         // --- for the scopes
         link_new_child_to_existing_parent_scope(ctx, &mut self.scope_buffer, self.current_scope, outer_scope_id, select_stmt_relative_pos);
         // Create statements that will create temporary variables for all of the
         // ports passed to the "get" calls in the select case guards.
         let select_stmt = &ctx.heap[id];
         let total_num_cases = select_stmt.cases.len();
         let mut total_num_ports = 0;
         let end_select_stmt_id = select_stmt.end_select;
         let _end_select = &ctx.heap[end_select_stmt_id];
         // Put heap IDs into temporary buffers to handle borrowing rules
         let mut call_id_section = self.call_expr_buffer.start_section();
         let mut expr_id_section = self.expression_buffer.start_section();
         for case in select_stmt.cases.iter() {
             total_num_ports += case.involved_ports.len();
             for (call_id, expr_id) in case.involved_ports.iter().copied() {
                 call_id_section.push(call_id);
                 expr_id_section.push(expr_id);
+            }
+        }
         // Transform all of the call expressions by takings its argument (the
         // port from which we `get`) and turning it into a temporary variable.
         let mut transformed_stmts = Vec::with_capacity(total_num_ports); // TODO: Recompute this preallocated length, put assert at the end
         let mut locals = Vec::with_capacity(total_num_ports);
         for port_var_idx in 0..call_id_section.len() {
             let get_call_expr_id = call_id_section[port_var_idx];
             let port_expr_id = expr_id_section[port_var_idx];
             let port_type_index = ctx.heap[port_expr_id].type_index();
             let port_type_ref = TypeIdReference::IndirectSameAsExpr(port_type_index);
             // Move the port expression such that it gets assigned to a temporary variable
             let variable_id = create_ast_variable(ctx, outer_scope_id);
             let variable_decl_stmt_id = create_ast_variable_declaration_stmt(ctx, self.current_procedure_id, variable_id, port_type_ref, port_expr_id);
             // Replace the original port expression in the call with a reference
             // to the replacement variable
             let variable_expr_id = create_ast_variable_expr(ctx, self.current_procedure_id, variable_id, port_type_ref);
             let call_expr = &mut ctx.heap[get_call_expr_id];
             call_expr.arguments[0] = variable_expr_id.upcast();
             transformed_stmts.push(variable_decl_stmt_id.upcast().upcast());
             locals.push((variable_id, port_type_ref));
+        }
         // Insert runtime calls that facilitate the semantics of the select
         // block.
         // Create the call that indicates the start of the select block
+        {
             let num_cases_expression_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, total_num_cases as u64, ctx.arch.uint32_type_id);
             let num_ports_expression_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, total_num_ports as u64, ctx.arch.uint32_type_id);
             let arguments = vec![
                 num_cases_expression_id.upcast(),
                 num_ports_expression_id.upcast()
             ];
             let call_expression_id = create_ast_call_expr(ctx, self.current_procedure_id, Method::SelectStart, &mut self.expression_buffer, arguments);
             let call_statement_id = create_ast_expression_stmt(ctx, call_expression_id.upcast());
             transformed_stmts.push(call_statement_id.upcast());
+        }
         // Create calls for each select case that will register the ports that
         // we are waiting on at the runtime.
+        {
             let mut total_port_index = 0;
             for case_index in 0..total_num_cases {
                 let case = &ctx.heap[id].cases[case_index];
                 let case_num_ports = case.involved_ports.len();
                 for case_port_index in 0..case_num_ports {
                     // Arguments to runtime call
                     let (port_variable_id, port_variable_type) = locals[total_port_index]; // so far this variable contains the temporary variables for the port expressions
                     let case_index_expr_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, case_index as u64, ctx.arch.uint32_type_id);
                     let port_index_expr_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, case_port_index as u64, ctx.arch.uint32_type_id);
                     let port_variable_expr_id = create_ast_variable_expr(ctx, self.current_procedure_id, port_variable_id, port_variable_type);
                     let runtime_call_arguments = vec![
                         case_index_expr_id.upcast(),
                         port_index_expr_id.upcast(),
                         port_variable_expr_id.upcast()
                     ];
                     // Create runtime call, then store it
                     let runtime_call_expr_id = create_ast_call_expr(ctx, self.current_procedure_id, Method::SelectRegisterCasePort, &mut self.expression_buffer, runtime_call_arguments);
                     let runtime_call_stmt_id = create_ast_expression_stmt(ctx, runtime_call_expr_id.upcast());
                     transformed_stmts.push(runtime_call_stmt_id.upcast());
                     total_port_index += 1;
+                }
+            }
+        }
         // Create the variable that will hold the result of a completed select
         // block. Then create the runtime call that will produce this result
         let select_variable_id = create_ast_variable(ctx, outer_scope_id);
         let select_variable_type = TypeIdReference::DirectTypeId(ctx.arch.uint32_type_id);
         locals.push((select_variable_id, select_variable_type));
+        {
             let runtime_call_expr_id = create_ast_call_expr(ctx, self.current_procedure_id, Method::SelectWait, &mut self.expression_buffer, Vec::new());
             let variable_stmt_id = create_ast_variable_declaration_stmt(ctx, self.current_procedure_id, select_variable_id, select_variable_type, runtime_call_expr_id.upcast());
             transformed_stmts.push(variable_stmt_id.upcast().upcast());
+        }
         call_id_section.forget();
         expr_id_section.forget();
         // Now we transform each of the select block case's guard and code into
         // a chained if-else statement.
-        let mut relative_pos = transformed_stmts.len() as i32;
         let relative_pos = transformed_stmts.len() as i32;
         if total_num_cases > 0 {
             let (if_stmt_id, end_if_stmt_id, scope_id) = transform_select_case_code(ctx, self.current_procedure_id, id, 0, select_variable_id, select_variable_type);
             link_existing_child_to_new_parent_scope(ctx, &mut self.scope_buffer, outer_scope_id, scope_id, relative_pos);
             let first_end_if_stmt = &mut ctx.heap[end_if_stmt_id];
             first_end_if_stmt.next = outer_end_block_id.upcast();
             let mut last_if_stmt_id = if_stmt_id;
             let mut last_end_if_stmt_id = end_if_stmt_id;
             let mut last_parent_scope_id = outer_scope_id;
             let mut last_relative_pos = transformed_stmts.len() as i32 + 1;
             transformed_stmts.push(last_if_stmt_id.upcast());
             for case_index in 1..total_num_cases {
                 let (if_stmt_id, end_if_stmt_id, scope_id) = transform_select_case_code(ctx, self.current_procedure_id, id, case_index, select_variable_id, select_variable_type);
                 let false_case_scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::If(last_if_stmt_id, false)));
                 link_existing_child_to_new_parent_scope(ctx, &mut self.scope_buffer, false_case_scope_id, scope_id, 0);
                 link_new_child_to_existing_parent_scope(ctx, &mut self.scope_buffer, last_parent_scope_id, false_case_scope_id, last_relative_pos);
                 set_ast_if_statement_false_body(ctx, last_if_stmt_id, last_end_if_stmt_id, IfStatementCase{ body: if_stmt_id.upcast(), scope: false_case_scope_id });
                 let end_if_stmt = &mut ctx.heap[end_if_stmt_id];
                 end_if_stmt.next = last_end_if_stmt_id.upcast();
                 last_if_stmt_id = if_stmt_id;
                 last_end_if_stmt_id = end_if_stmt_id;
                 last_parent_scope_id = false_case_scope_id;
                 last_relative_pos = 0;
+            }
+        }
         // Final steps: set the statements of the replacement block statement,
         // link all of those statements together, and update the scopes.
         let first_stmt_id = transformed_stmts[0];
         let mut last_stmt_id = transformed_stmts[0];
         for stmt_id in transformed_stmts.iter().skip(1).copied() {
             set_ast_statement_next(ctx, last_stmt_id, stmt_id);
             last_stmt_id = stmt_id;
+        }
         if total_num_cases == 0 {
             // If we don't have any cases, then we didn't connect the statements
             // up to the end of the outer block, so do that here
             set_ast_statement_next(ctx, last_stmt_id, outer_end_block_id.upcast());
+        }
         let outer_block_stmt = &mut ctx.heap[outer_block_id];
         outer_block_stmt.next = first_stmt_id;
         outer_block_stmt.statements = transformed_stmts;
         return Ok(())
+    }
+}
 // -----------------------------------------------------------------------------
 // Utilities to create compiler-generated AST nodes
 // -----------------------------------------------------------------------------
 #[derive(Clone, Copy)]
 enum TypeIdReference {
     DirectTypeId(TypeId),
     IndirectSameAsExpr(i32), // by type index
+}
 fn create_ast_variable(ctx: &mut Ctx, scope_id: ScopeId) -> VariableId {
     let variable_id = ctx.heap.alloc_variable(|this| Variable{
         this,
         kind: VariableKind::Local,
         parser_type: ParserType{
             elements: Vec::new(),
             full_span: InputSpan::new(),
         },
         identifier: Identifier::new_empty(InputSpan::new()),
         relative_pos_in_parent: -1,
         unique_id_in_scope: -1,
     });
     let scope = &mut ctx.heap[scope_id];
     scope.variables.push(variable_id);
     return variable_id;
+}
 fn create_ast_variable_expr(ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId, variable_id: VariableId, variable_type_id: TypeIdReference) -> VariableExpressionId {
     let variable_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, variable_type_id);
     return ctx.heap.alloc_variable_expression(|this| VariableExpression{
         this,
         identifier: Identifier::new_empty(InputSpan::new()),
         declaration: Some(variable_id),
         used_as_binding_target: false,
         parent: ExpressionParent::None,
         type_index: variable_type_index,
     });
+}
 fn create_ast_call_expr(ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId, method: Method, buffer: &mut ScopedBuffer<ExpressionId>, arguments: Vec<ExpressionId>) -> CallExpressionId {
     let call_type_id = match method {
         Method::SelectStart => ctx.arch.void_type_id,
         Method::SelectRegisterCasePort => ctx.arch.void_type_id,
         Method::SelectWait => ctx.arch.uint32_type_id, // TODO: Not pretty, this. Pretty error prone
         _ => unreachable!(), // if this goes of, add the appropriate method here.
     };
     let expression_ids = buffer.start_section_initialized(&arguments);
     let call_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(call_type_id));
     let call_expression_id = ctx.heap.alloc_call_expression(|this| CallExpression{
         func_span: InputSpan::new(),
         this,
         full_span: InputSpan::new(),
         parser_type: ParserType{
             elements: Vec::new(),
             full_span: InputSpan::new(),
         },
         method,
         arguments,
         procedure: ProcedureDefinitionId::new_invalid(),
         parent: ExpressionParent::None,
         type_index: call_type_index,
     });
     for argument_index in 0..expression_ids.len() {
         let argument_id = expression_ids[argument_index];
         let argument_expr = &mut ctx.heap[argument_id];
         *argument_expr.parent_mut() = ExpressionParent::Expression(call_expression_id.upcast(), argument_index as u32);
+    }
     return call_expression_id;
+}
 fn create_ast_literal_integer_expr(ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId, unsigned_value: u64, type_id: TypeId) -> LiteralExpressionId {
     let literal_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(type_id));
     return ctx.heap.alloc_literal_expression(|this| LiteralExpression{
         this,
         span: InputSpan::new(),
         value: Literal::Integer(LiteralInteger{
             unsigned_value,
             negated: false,
         }),
         parent: ExpressionParent::None,
         type_index: literal_type_index,
     });
+}
 fn create_ast_equality_comparison_expr(
     ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId,
     variable_id: VariableId, variable_type: TypeIdReference, value: u64
 ) -> BinaryExpressionId {
     let var_expr_id = create_ast_variable_expr(ctx, containing_procedure_id, variable_id, variable_type);
     let int_expr_id = create_ast_literal_integer_expr(ctx, containing_procedure_id, value, ctx.arch.uint32_type_id);
     let cmp_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(ctx.arch.bool_type_id));
     let cmp_expr_id = ctx.heap.alloc_binary_expression(|this| BinaryExpression{
         this,
         operator_span: InputSpan::new(),
         full_span: InputSpan::new(),
         left: var_expr_id.upcast(),
         operation: BinaryOperator::Equality,
         right: int_expr_id.upcast(),
         parent: ExpressionParent::None,
         type_index: cmp_type_index,
     });
     let var_expr = &mut ctx.heap[var_expr_id];
     var_expr.parent = ExpressionParent::Expression(cmp_expr_id.upcast(), 0);
     let int_expr = &mut ctx.heap[int_expr_id];
     int_expr.parent = ExpressionParent::Expression(cmp_expr_id.upcast(), 1);
     return cmp_expr_id;
+}
 fn create_ast_expression_stmt(ctx: &mut Ctx, expression_id: ExpressionId) -> ExpressionStatementId {
     let statement_id = ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
         this,
         span: InputSpan::new(),
         expression: expression_id,
         next: StatementId::new_invalid(),
     });
     let expression = &mut ctx.heap[expression_id];
     *expression.parent_mut() = ExpressionParent::ExpressionStmt(statement_id);
     return statement_id;
+}
 fn create_ast_variable_declaration_stmt(
     ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId,
     variable_id: VariableId, variable_type: TypeIdReference, initial_value_expr_id: ExpressionId
 ) -> MemoryStatementId {
     // Create the assignment expression, assigning the initial value to the variable
     let variable_expr_id = create_ast_variable_expr(ctx, containing_procedure_id, variable_id, variable_type);
     let void_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(ctx.arch.void_type_id));
     let assignment_expr_id = ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
         this,
         operator_span: InputSpan::new(),
         full_span: InputSpan::new(),
         left: variable_expr_id.upcast(),
         operation: AssignmentOperator::Set,
         right: initial_value_expr_id,
         parent: ExpressionParent::None,
         type_index: void_type_index,
     });
     // Create the memory statement
     let memory_stmt_id = ctx.heap.alloc_memory_statement(|this| MemoryStatement{
         this,
         span: InputSpan::new(),
         variable: variable_id,
         initial_expr: assignment_expr_id,
         next: StatementId::new_invalid(),
     });
     // Set all parents which we can access
     let variable_expr = &mut ctx.heap[variable_expr_id];
     variable_expr.parent = ExpressionParent::Expression(assignment_expr_id.upcast(), 0);
     let value_expr = &mut ctx.heap[initial_value_expr_id];
     *value_expr.parent_mut() = ExpressionParent::Expression(assignment_expr_id.upcast(), 1);
     let assignment_expr = &mut ctx.heap[assignment_expr_id];
     assignment_expr.parent = ExpressionParent::Memory(memory_stmt_id);
     return memory_stmt_id;
+}
 fn create_ast_block_stmt(ctx: &mut Ctx, statements: Vec<StatementId>) -> (BlockStatementId, EndBlockStatementId, ScopeId) {
     let block_stmt_id = ctx.heap.alloc_block_statement(|this| BlockStatement{
         this,
         span: InputSpan::new(),
         statements,
         end_block: EndBlockStatementId::new_invalid(),
         scope: ScopeId::new_invalid(),
         next: StatementId::new_invalid(),
     });
     let end_block_stmt_id = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
         this,
         start_block: block_stmt_id,
         next: StatementId::new_invalid(),
     });
     let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Block(block_stmt_id)));
     let block_stmt = &mut ctx.heap[block_stmt_id];
     block_stmt.end_block = end_block_stmt_id;
     block_stmt.scope = scope_id;
     return (block_stmt_id, end_block_stmt_id, scope_id);
+}
 fn create_ast_if_stmt(ctx: &mut Ctx, condition_expression_id: ExpressionId, true_case: IfStatementCase, false_case: Option<IfStatementCase>) -> (IfStatementId, EndIfStatementId) {
     // Create if statement and the end-if statement
     let if_stmt_id = ctx.heap.alloc_if_statement(|this| IfStatement{
         this,
         span: InputSpan::new(),
         test: condition_expression_id,
         true_case,
         false_case,
         end_if: EndIfStatementId::new_invalid()
     });
     let end_if_stmt_id = ctx.heap.alloc_end_if_statement(|this| EndIfStatement{
         this,
         start_if: if_stmt_id,
         next: StatementId::new_invalid(),
     });
     // Link the statements up as much as we can
     let if_stmt = &mut ctx.heap[if_stmt_id];
     if_stmt.end_if = end_if_stmt_id;
     let condition_expr = &mut ctx.heap[condition_expression_id];
     *condition_expr.parent_mut() = ExpressionParent::If(if_stmt_id);
     return (if_stmt_id, end_if_stmt_id);
+}
 /// Sets the false body for a given
 fn set_ast_if_statement_false_body(ctx: &mut Ctx, if_statement_id: IfStatementId, end_if_statement_id: EndIfStatementId, false_case: IfStatementCase) {
     // Point if-statement to "false body"
     let if_stmt = &mut ctx.heap[if_statement_id];
     debug_assert!(if_stmt.false_case.is_none()); // simplifies logic, not necessary
     if_stmt.false_case = Some(false_case);
     // Point end of false body to the end of the if statement
     set_ast_statement_next(ctx, false_case.body, end_if_statement_id.upcast());
+}
 /// Sets the specified AST statement's control flow such that it will be
 /// followed by the target statement. This may seem obvious, but may imply that
 /// a statement associated with, but different from, the source statement is
 /// modified.
 fn set_ast_statement_next(ctx: &mut Ctx, source_stmt_id: StatementId, target_stmt_id: StatementId) {
     let source_stmt = &mut ctx.heap[source_stmt_id];
     match source_stmt {
         Statement::Block(stmt) => {
             let end_id = stmt.end_block;
             ctx.heap[end_id].next = target_stmt_id
         },
         Statement::EndBlock(stmt) => stmt.next = target_stmt_id,
         Statement::Local(stmt) => {
             match stmt {
                 LocalStatement::Memory(stmt) => stmt.next = target_stmt_id,
                 LocalStatement::Channel(stmt) => stmt.next = target_stmt_id,
+            }
         },
         Statement::Labeled(stmt) => {
             let body_id = stmt.body;
             set_ast_statement_next(ctx, body_id, target_stmt_id);
         },
         Statement::If(stmt) => {
             let end_id = stmt.end_if;
             ctx.heap[end_id].next = target_stmt_id;
         },
         Statement::EndIf(stmt) => stmt.next = target_stmt_id,
         Statement::While(stmt) => {
             let end_id = stmt.end_while;
             ctx.heap[end_id].next = target_stmt_id;
         },
         Statement::EndWhile(stmt) => stmt.next = target_stmt_id,
         Statement::Break(_stmt) => {},
         Statement::Continue(_stmt) => {},
         Statement::Synchronous(stmt) => {
             let end_id = stmt.end_sync;
             ctx.heap[end_id].next = target_stmt_id;
         },
         Statement::EndSynchronous(stmt) => {
             stmt.next = target_stmt_id;
         },
         Statement::Fork(_) | Statement::EndFork(_) => {
             todo!("remove fork from language");
         },
         Statement::Select(stmt) => {
             let end_id = stmt.end_select;
             ctx.heap[end_id].next = target_stmt_id;
         },
         Statement::EndSelect(stmt) => stmt.next = target_stmt_id,
         Statement::Return(_stmt) => {},
         Statement::Goto(_stmt) => {},
         Statement::New(stmt) => stmt.next = target_stmt_id,
         Statement::Expression(stmt) => stmt.next = target_stmt_id,
+    }
+}
 /// Links a new scope to an existing scope as its child.
 fn link_new_child_to_existing_parent_scope(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, parent_scope_id: ScopeId, child_scope_id: ScopeId, relative_pos_hint: i32) {
     let child_scope = &mut ctx.heap[child_scope_id];
     debug_assert!(child_scope.parent.is_none());
     child_scope.parent = Some(parent_scope_id);
     child_scope.relative_pos_in_parent = relative_pos_hint;
     add_child_scope_to_parent(ctx, scope_buffer, parent_scope_id, child_scope_id, relative_pos_hint);
+}
 /// Relinks an existing scope to a new scope as its child. Will also break the
 /// link of the child scope's old parent.
 fn link_existing_child_to_new_parent_scope(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, new_parent_scope_id: ScopeId, child_scope_id: ScopeId, new_relative_pos_in_parent: i32) {
     let child_scope = &mut ctx.heap[child_scope_id];
     let old_parent_scope_id = child_scope.parent.unwrap();
     child_scope.parent = Some(new_parent_scope_id);
     child_scope.relative_pos_in_parent = new_relative_pos_in_parent;
     // Remove from old parent
     let old_parent = &mut ctx.heap[old_parent_scope_id];
     let scope_index = old_parent.nested.iter()
         .position(|v| *v == child_scope_id)
         .unwrap();
     old_parent.nested.remove(scope_index);
     // Add to new parent
     add_child_scope_to_parent(ctx, scope_buffer, new_parent_scope_id, child_scope_id, new_relative_pos_in_parent);
+}
 /// Will add a child scope to a parent scope using the relative position hint.
 fn add_child_scope_to_parent(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, parent_scope_id: ScopeId, child_scope_id: ScopeId, relative_pos_hint: i32) {
     let parent_scope = &ctx.heap[parent_scope_id];
     let existing_scope_ids = scope_buffer.start_section_initialized(&parent_scope.nested);
     let mut insert_pos = existing_scope_ids.len();
     for index in 0..existing_scope_ids.len() {
         let existing_scope_id = existing_scope_ids[index];
         let existing_scope = &ctx.heap[existing_scope_id];
         if relative_pos_hint <= existing_scope.relative_pos_in_parent {
             insert_pos = index;
             break;
+        }
+    }
     existing_scope_ids.forget();

src/protocol/parser/pass_validation_linking.rs

➞

Show inline comments

@@ @@ -912,773 +912,773 @@ impl Visitor for PassValidationLinking { @@
                 let mut specified = Vec::new(); // TODO: @performance
                 specified.resize(struct_definition.fields.len(), false);
                 for field in &mut literal.fields {
                     // Find field in the struct definition
                     let field_idx = struct_definition.fields.iter().position(|v| v.identifier == field.identifier);
                     if field_idx.is_none() {
                         let field_span = field.identifier.span;
                         let literal = ctx.heap[id].value.as_struct();
                         let ast_definition = &ctx.heap[literal.definition];
                         return Err(ParseError::new_error_at_span(
                             &ctx.module().source, field_span, format!(
                                 "This field does not exist on the struct '{}'",
                                 ast_definition.identifier().value.as_str()
+                            )
                         ));
+                    }
                     field.field_idx = field_idx.unwrap();
                     // Check if specified more than once
                     if specified[field.field_idx] {
                         let field_span = field.identifier.span;
                         return Err(ParseError::new_error_str_at_span(
                             &ctx.module().source, field_span,
                             "This field is specified more than once"
                         ));
+                    }
                     specified[field.field_idx] = true;
+                }
                 if !specified.iter().all(|v| *v) {
                     // Some fields were not specified
                     let mut not_specified = String::new();
                     let mut num_not_specified = 0;
                     for (def_field_idx, is_specified) in specified.iter().enumerate() {
                         if !is_specified {
                             if !not_specified.is_empty() { not_specified.push_str(", ") }
                             let field_ident = &struct_definition.fields[def_field_idx].identifier;
                             not_specified.push_str(field_ident.value.as_str());
                             num_not_specified += 1;
+                        }
+                    }
                     debug_assert!(num_not_specified > 0);
                     let msg = if num_not_specified == 1 {
                         format!("not all fields are specified, '{}' is missing", not_specified)
                     } else {
                         format!("not all fields are specified, [{}] are missing", not_specified)
                     };
                     let literal_span = literal.parser_type.full_span;
                     return Err(ParseError::new_error_at_span(
                         &ctx.module().source, literal_span, msg
                     ));
+                }
                 // Need to traverse fields expressions in struct and evaluate
                 // the poly args
                 let mut expr_section = self.expression_buffer.start_section();
                 for field in &literal.fields {
                     expr_section.push(field.value);
+                }
                 for expr_idx in 0..expr_section.len() {
                     let expr_id = expr_section[expr_idx];
                     self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
                     self.visit_expr(ctx, expr_id)?;
+                }
                 expr_section.forget();
             },
             Literal::Enum(literal) => {
                 // Make sure the variant exists
                 let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
                 let enum_definition = type_definition.definition.as_enum();
                 let variant_idx = enum_definition.variants.iter().position(|v| {
                     v.identifier == literal.variant
                 });
                 if variant_idx.is_none() {
                     let literal = ctx.heap[id].value.as_enum();
                     let ast_definition = ctx.heap[literal.definition].as_enum();
                     return Err(ParseError::new_error_at_span(
                         &ctx.module().source, literal.parser_type.full_span, format!(
                             "the variant '{}' does not exist on the enum '{}'",
                             literal.variant.value.as_str(), ast_definition.identifier.value.as_str()
+                        )
                     ));
+                }
                 literal.variant_idx = variant_idx.unwrap();
             },
             Literal::Union(literal) => {
                 // Make sure the variant exists
                 let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
                 let union_definition = type_definition.definition.as_union();
                 let variant_idx = union_definition.variants.iter().position(|v| {
                     v.identifier == literal.variant
                 });
                 if variant_idx.is_none() {
                     let literal = ctx.heap[id].value.as_union();
                     let ast_definition = ctx.heap[literal.definition].as_union();
                     return Err(ParseError::new_error_at_span(
                         &ctx.module().source, literal.parser_type.full_span, format!(
                             "the variant '{}' does not exist on the union '{}'",
                             literal.variant.value.as_str(), ast_definition.identifier.value.as_str()
+                        )
                     ));
+                }
                 literal.variant_idx = variant_idx.unwrap();
                 // Make sure the number of specified values matches the expected
                 // number of embedded values in the union variant.
                 let union_variant = &union_definition.variants[literal.variant_idx];
                 if union_variant.embedded.len() != literal.values.len() {
                     let literal = ctx.heap[id].value.as_union();
                     let ast_definition = ctx.heap[literal.definition].as_union();
                     return Err(ParseError::new_error_at_span(
                         &ctx.module().source, literal.parser_type.full_span, format!(
                             "The variant '{}' of union '{}' expects {} embedded values, but {} were specified",
                             literal.variant.value.as_str(), ast_definition.identifier.value.as_str(),
                             union_variant.embedded.len(), literal.values.len()
                         ),
                     ))
+                }
                 // Traverse embedded values of union (if any) and evaluate the
                 // polymorphic arguments
                 let upcast_id = id.upcast();
                 let mut expr_section = self.expression_buffer.start_section();
                 for value in &literal.values {
                     expr_section.push(*value);
+                }
                 for expr_idx in 0..expr_section.len() {
                     let expr_id = expr_section[expr_idx];
                     self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
                     self.visit_expr(ctx, expr_id)?;
+                }
                 expr_section.forget();
             },
             Literal::Array(literal) | Literal::Tuple(literal) => {
                 // Visit all expressions in the array
                 let upcast_id = id.upcast();
                 let expr_section = self.expression_buffer.start_section_initialized(literal);
                 for expr_idx in 0..expr_section.len() {
                     let expr_id = expr_section[expr_idx];
                     self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
                     self.visit_expr(ctx, expr_id)?;
+                }
                 expr_section.forget();
+            }
+        }
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_cast_expr(&mut self, ctx: &mut Ctx, id: CastExpressionId) -> VisitorResult {
         let cast_expr = &mut ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a cast expression"
             ))
+        }
         let upcast_id = id.upcast();
         let old_expr_parent = self.expr_parent;
         cast_expr.parent = old_expr_parent;
         // Recurse into the thing that we're casting
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         let subject_id = cast_expr.subject;
         self.visit_expr(ctx, subject_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> VisitorResult {
         let call_expr = &ctx.heap[id];
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a call expression"
             ))
+        }
         // Check whether the method is allowed to be called within the code's
         // context (in sync, definition type, etc.)
         let mut expecting_wrapping_new_stmt = false;
         let mut expecting_primitive_def = false;
         let mut expecting_wrapping_sync_stmt = false;
         let mut expecting_no_select_stmt = false;
         match call_expr.method {
             Method::Get => {
                 expecting_primitive_def = true;
                 expecting_wrapping_sync_stmt = true;
                 if !self.in_select_guard.is_invalid() {
                     // In a select guard. Take the argument (i.e. the port we're
                     // retrieving from) and add it to the list of involved ports
                     // of the guard
                     if call_expr.arguments.len() == 1 {
                         // We're checking the number of arguments later, for now
                         // assume it is correct.
                         let argument = call_expr.arguments[0];
                         let select_stmt = &mut ctx.heap[self.in_select_guard];
                         let select_case = &mut select_stmt.cases[self.in_select_arm as usize];
                         select_case.involved_ports.push((id, argument));
+                    }
+                }
             },
             Method::Put => {
                 expecting_primitive_def = true;
                 expecting_wrapping_sync_stmt = true;
                 expecting_no_select_stmt = true;
             },
             Method::Fires => {
                 expecting_primitive_def = true;
                 expecting_wrapping_sync_stmt = true;
             },
             Method::Create => {},
             Method::Length => {},
             Method::Assert => {
                 expecting_wrapping_sync_stmt = true;
                 expecting_no_select_stmt = true;
                 if self.proc_kind == ProcedureKind::Function {
                     let call_span = call_expr.func_span;
                     return Err(ParseError::new_error_str_at_span(
                         &ctx.module().source, call_span,
                         "assert statement may only occur in components"
                     ));
+                }
             },
             Method::Print => {},
             Method::SelectStart
             | Method::SelectRegisterCasePort
             | Method::SelectWait => unreachable!(), // not usable by programmer directly
             Method::UserFunction => {}
             Method::UserComponent => {
                 expecting_wrapping_new_stmt = true;
             },
+        }
         let call_expr = &mut ctx.heap[id];
         fn get_span_and_name<'a>(ctx: &'a Ctx, id: CallExpressionId) -> (InputSpan, String) {
             let call = &ctx.heap[id];
             let span = call.func_span;
             let name = String::from_utf8_lossy(ctx.module().source.section_at_span(span)).to_string();
             return (span, name);
+        }
         if expecting_primitive_def {
             if self.proc_kind != ProcedureKind::Primitive {
                 let (call_span, func_name) = get_span_and_name(ctx, id);
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, call_span,
                     format!("a call to '{}' may only occur in primitive component definitions", func_name)
                 ));
+            }
+        }
         if expecting_wrapping_sync_stmt {
             if self.in_sync.is_invalid() {
                 let (call_span, func_name) = get_span_and_name(ctx, id);
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, call_span,
                     format!("a call to '{}' may only occur inside synchronous blocks", func_name)
                 ))
+            }
+        }
         if expecting_no_select_stmt {
             if !self.in_select_guard.is_invalid() {
                 let (call_span, func_name) = get_span_and_name(ctx, id);
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, call_span,
                     format!("a call to '{}' may not occur in a select statement's guard", func_name)
                 ));
+            }
+        }
         if expecting_wrapping_new_stmt {
             if !self.expr_parent.is_new() {
                 let call_span = call_expr.func_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, call_span,
                     "cannot call a component, it can only be instantiated by using 'new'"
                 ));
+            }
         } else {
             if self.expr_parent.is_new() {
                 let call_span = call_expr.func_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, call_span,
                     "only components can be instantiated, this is a function"
                 ));
+            }
+        }
         // Check the number of arguments
         let call_definition = ctx.types.get_base_definition(&call_expr.procedure.upcast()).unwrap();
         let num_expected_args = match &call_definition.definition {
             DefinedTypeVariant::Procedure(definition) => definition.arguments.len(),
             _ => unreachable!(),
         };
         let num_provided_args = call_expr.arguments.len();
         if num_provided_args != num_expected_args {
             let argument_text = if num_expected_args == 1 { "argument" } else { "arguments" };
             let call_span = call_expr.full_span;
             return Err(ParseError::new_error_at_span(
                 &ctx.module().source, call_span, format!(
                     "expected {} {}, but {} were provided",
                     num_expected_args, argument_text, num_provided_args
+                )
             ));
+        }
         // Recurse into all of the arguments and set the expression's parent
         let upcast_id = id.upcast();
         let section = self.expression_buffer.start_section_initialized(&call_expr.arguments);
         let old_expr_parent = self.expr_parent;
         call_expr.parent = old_expr_parent;
         for arg_expr_idx in 0..section.len() {
             let arg_expr_id = section[arg_expr_idx];
             self.expr_parent = ExpressionParent::Expression(upcast_id, arg_expr_idx as u32);
             self.visit_expr(ctx, arg_expr_id)?;
+        }
         section.forget();
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> VisitorResult {
         let var_expr = &ctx.heap[id];
         // Check if declaration was already resolved (this occurs for the
         // variable expr that is on the LHS of the assignment expr that is
         // associated with a variable declaration)
         let mut variable_id = var_expr.declaration;
         let mut is_binding_target = false;
         // Otherwise try to find it
         if variable_id.is_none() {
             variable_id = self.find_variable(ctx, self.relative_pos_in_parent, &var_expr.identifier);
+        }
         // Otherwise try to see if is a variable introduced by a binding expr
         let variable_id = if let Some(variable_id) = variable_id {
             variable_id
         } else {
             if self.in_binding_expr.is_invalid() || !self.in_binding_expr_lhs {
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, var_expr.identifier.span, "unresolved variable"
                 ));
+            }
             // This is a binding variable, but it may only appear in very
             // specific locations.
             let is_valid_binding = match self.expr_parent {
                 ExpressionParent::Expression(expr_id, idx) => {
                     match &ctx.heap[expr_id] {
                         Expression::Binding(_binding_expr) => {
                             // Nested binding is disallowed, and because of
                             // the check above we know we're directly at the
                             // LHS of the binding expression
                             debug_assert_eq!(_binding_expr.this, self.in_binding_expr);
                             debug_assert_eq!(idx, 0);
                             true
+                        }
-                        Expression::Literal(lit_expr) => {
+                        Expression::Literal(_lit_expr) => {
                             // Only struct, unions, tuples and arrays can
                             // have subexpressions, so we're always fine
                             dbg_code!({
-                                match lit_expr.value {
+                                match _lit_expr.value {
                                     Literal::Struct(_) | Literal::Union(_) | Literal::Array(_) | Literal::Tuple(_) => {},
                                     _ => unreachable!(),
+                                }
                             });
                             true
                         },
                         _ => false,
+                    }
                 },
                 _ => {
                     false
+                }
             };
             if !is_valid_binding {
                 let binding_expr = &ctx.heap[self.in_binding_expr];
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, var_expr.identifier.span,
                     "illegal location for binding variable: binding variables may only be nested under a binding expression, or a struct, union or array literal"
                 ).with_info_at_span(
                     &ctx.module().source, binding_expr.operator_span, format!(
                         "'{}' was interpreted as a binding variable because the variable is not declared and it is nested under this binding expression",
                         var_expr.identifier.value.as_str()
+                    )
                 ));
+            }
             // By now we know that this is a valid binding expression. Given
             // that a binding expression must be nested under an if/while
             // statement, we now add the variable to the scope associated with
             // that statement.
             let bound_identifier = var_expr.identifier.clone();
             let bound_variable_id = ctx.heap.alloc_variable(|this| Variable {
                 this,
                 kind: VariableKind::Binding,
                 parser_type: ParserType {
                     elements: vec![ParserTypeElement {
                         element_span: bound_identifier.span,
                         variant: ParserTypeVariant::Inferred
                     }],
                     full_span: bound_identifier.span
                 },
                 identifier: bound_identifier,
                 relative_pos_in_parent: 0,
                 unique_id_in_scope: -1,
             });
             let scope_id = match &ctx.heap[self.in_test_expr] {
                 Statement::If(stmt) => stmt.true_case.scope,
                 Statement::While(stmt) => stmt.scope,
                 _ => unreachable!(),
             };
             self.checked_at_single_scope_add_local(ctx, scope_id, -1, bound_variable_id)?; // add at -1 such that first statement can find the variable if needed
             is_binding_target = true;
             bound_variable_id
         };
         let var_expr = &mut ctx.heap[id];
         var_expr.declaration = Some(variable_id);
         var_expr.used_as_binding_target = is_binding_target;
         var_expr.parent = self.expr_parent;
         Ok(())
+    }
+}
 impl PassValidationLinking {
     //--------------------------------------------------------------------------
     // Special traversal
     //--------------------------------------------------------------------------
     /// Pushes a new scope associated with a particular statement. If that
     /// statement already has an associated scope (i.e. scope associated with
     /// sync statement or select statement's arm) then we won't do anything.
     /// In all cases the caller must call `pop_statement_scope` with the scope
     /// and relative scope position returned by this function.
     fn push_scope(&mut self, ctx: &mut Ctx, is_top_level_scope: bool, pushed_scope_id: ScopeId) -> (ScopeId, i32) {
         // Set the properties of the pushed scope (it is already created during
         // AST construction, but most values are not yet set to their correct
         // values)
         let old_scope_id = self.cur_scope;
         let scope = &mut ctx.heap[pushed_scope_id];
         if !is_top_level_scope {
             scope.parent = Some(old_scope_id);
+        }
         scope.relative_pos_in_parent = self.relative_pos_in_parent;
         let old_relative_pos = self.relative_pos_in_parent;
         self.relative_pos_in_parent = 0;
         // Link up scopes
         if !is_top_level_scope {
             let old_scope = &mut ctx.heap[old_scope_id];
             old_scope.nested.push(pushed_scope_id);
+        }
         // Set as current traversal scope, then return old scope
         self.cur_scope = pushed_scope_id;
         return (old_scope_id, old_relative_pos)
+    }
     fn pop_scope(&mut self, scope_to_restore: (ScopeId, i32)) {
         self.cur_scope = scope_to_restore.0;
         self.relative_pos_in_parent = scope_to_restore.1;
+    }
     fn resolve_pending_control_flow_targets(&mut self, ctx: &mut Ctx) -> Result<(), ParseError> {
         for entry in &self.control_flow_stmts {
             let stmt = &ctx.heap[entry.statement];
             match stmt {
                 Statement::Break(stmt) => {
                     let stmt_id = stmt.this;
                     let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
                     let target_while_stmt = &ctx.heap[target_while_id];
                     let target_end_while_id = target_while_stmt.end_while;
                     debug_assert!(!target_end_while_id.is_invalid());
                     let break_stmt = &mut ctx.heap[stmt_id];
                     break_stmt.target = target_end_while_id;
                 },
                 Statement::Continue(stmt) => {
                     let stmt_id = stmt.this;
                     let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
                     let continue_stmt = &mut ctx.heap[stmt_id];
                     continue_stmt.target = target_while_id;
                 },
                 Statement::Goto(stmt) => {
                     let stmt_id = stmt.this;
                     let target_id = Self::find_label(entry.in_scope, ctx, &stmt.label)?;
                     let target_stmt = &ctx.heap[target_id];
                     if entry.in_sync != target_stmt.in_sync {
                         // Nested sync not allowed. And goto can only go to
                         // outer scopes, so we must be escaping from a sync.
                         debug_assert!(target_stmt.in_sync.is_invalid());    // target not in sync
                         debug_assert!(!entry.in_sync.is_invalid()); // but the goto is in sync
                         let goto_stmt = &ctx.heap[stmt_id];
                         let sync_stmt = &ctx.heap[entry.in_sync];
                         return Err(
                             ParseError::new_error_str_at_span(&ctx.module().source, goto_stmt.span, "goto may not escape the surrounding synchronous block")
                             .with_info_str_at_span(&ctx.module().source, target_stmt.label.span, "this is the target of the goto statement")
                             .with_info_str_at_span(&ctx.module().source, sync_stmt.span, "which will jump past this statement")
                         );
+                    }
                     let goto_stmt = &mut ctx.heap[stmt_id];
                     goto_stmt.target = target_id;
                 },
                 _ => unreachable!("cannot resolve control flow target for {:?}", stmt),
+            }
+        }
         return Ok(())
+    }
     //--------------------------------------------------------------------------
     // Utilities
     //--------------------------------------------------------------------------
     /// Adds a local variable to the current scope. It will also annotate the
     /// `Local` in the AST with its relative position in the block.
     fn checked_add_local(&mut self, ctx: &mut Ctx, target_scope_id: ScopeId, target_relative_pos: i32, new_variable_id: VariableId) -> Result<(), ParseError> {
         let new_variable = &ctx.heap[new_variable_id];
         // We immediately go to the parent scope. We check the target scope
         // in the call at the end. That is also where we check for collisions
         // with symbols.
         let mut scope = &ctx.heap[target_scope_id];
         let mut cur_relative_pos = scope.relative_pos_in_parent;
         while let Some(scope_parent_id) = scope.parent {
             scope = &ctx.heap[scope_parent_id];
             // Check for collisions
             for variable_id in scope.variables.iter().copied() {
                 let existing_variable = &ctx.heap[variable_id];
                 if existing_variable.identifier == new_variable.identifier &&
                     existing_variable.this != new_variable_id &&
                     cur_relative_pos >= existing_variable.relative_pos_in_parent {
                     return Err(
                         ParseError::new_error_str_at_span(
                             &ctx.module().source, new_variable.identifier.span, "Local variable name conflicts with another variable"
                         ).with_info_str_at_span(
                             &ctx.module().source, existing_variable.identifier.span, "Previous variable is found here"
+                        )
                     );
+                }
+            }
             cur_relative_pos = scope.relative_pos_in_parent;
+        }
         // No collisions in any of the parent scope, attempt to add to scope
         self.checked_at_single_scope_add_local(ctx, target_scope_id, target_relative_pos, new_variable_id)
+    }
     /// Adds a local variable to the specified scope. Will check the specified
     /// scope for variable conflicts and the symbol table for global conflicts.
     /// Will NOT check parent scopes of the specified scope.
     fn checked_at_single_scope_add_local(
         &mut self, ctx: &mut Ctx, scope_id: ScopeId, relative_pos: i32, new_variable_id: VariableId
     ) -> Result<(), ParseError> {
         // Check the symbol table for conflicts
+        {
             let cur_scope = SymbolScope::Definition(self.proc_id.upcast());
             let ident = &ctx.heap[new_variable_id].identifier;
             if let Some(symbol) = ctx.symbols.get_symbol_by_name(cur_scope, &ident.value.as_bytes()) {
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, ident.span,
                     "local variable declaration conflicts with symbol"
                 ).with_info_str_at_span(
                     &ctx.module().source, symbol.variant.span_of_introduction(&ctx.heap), "the conflicting symbol is introduced here"
                 ));
+            }
+        }
         // Check the specified scope for conflicts
         let new_variable = &ctx.heap[new_variable_id];
         let scope = &ctx.heap[scope_id];
         for variable_id in scope.variables.iter().copied() {
             let old_variable = &ctx.heap[variable_id];
             if new_variable.this != old_variable.this &&
                 // relative_pos >= other_local.relative_pos_in_block &&
                 new_variable.identifier == old_variable.identifier {
                 // Collision
                 return Err(
                     ParseError::new_error_str_at_span(
                         &ctx.module().source, new_variable.identifier.span, "Local variable name conflicts with another variable"
                     ).with_info_str_at_span(
                         &ctx.module().source, old_variable.identifier.span, "Previous variable is found here"
+                    )
                 );
+            }
+        }
         // No collisions
         let scope = &mut ctx.heap[scope_id];
         scope.variables.push(new_variable_id);
         let variable = &mut ctx.heap[new_variable_id];
         variable.relative_pos_in_parent = relative_pos;
         Ok(())
+    }
     /// Finds a variable in the visitor's scope that must appear before the
     /// specified relative position within that block.
     fn find_variable(&self, ctx: &Ctx, mut relative_pos: i32, identifier: &Identifier) -> Option<VariableId> {
         let mut scope_id = self.cur_scope;
         loop {
             // Check if we can find the variable in the current scope
             let scope = &ctx.heap[scope_id];
             for variable_id in scope.variables.iter().copied() {
                 let variable = &ctx.heap[variable_id];
                 if variable.relative_pos_in_parent < relative_pos && identifier == &variable.identifier {
                     return Some(variable_id);
+                }
+            }
             // Could not find variable, move to parent scope and try again
             if scope.parent.is_none() {
                 return None;
+            }
             scope_id = scope.parent.unwrap();
             relative_pos = scope.relative_pos_in_parent;
+        }
+    }
     /// Adds a particular label to the current scope. Will return an error if
     /// there is another label with the same name visible in the current scope.
     fn checked_add_label(&mut self, ctx: &mut Ctx, relative_pos: i32, in_sync: SynchronousStatementId, new_label_id: LabeledStatementId) -> Result<(), ParseError> {
         // Make sure label is not defined within the current scope or any of the
         // parent scope.
         let new_label = &mut ctx.heap[new_label_id];
         new_label.relative_pos_in_parent = relative_pos;
         new_label.in_sync = in_sync;
         let new_label = &ctx.heap[new_label_id];
         let mut scope_id = self.cur_scope;
         loop {
             let scope = &ctx.heap[scope_id];
             for existing_label_id in scope.labels.iter().copied() {
                 let existing_label = &ctx.heap[existing_label_id];
                 if existing_label.label == new_label.label {
                     // Collision
                     return Err(ParseError::new_error_str_at_span(
                         &ctx.module().source, new_label.label.span, "label name is used more than once"
                     ).with_info_str_at_span(
                         &ctx.module().source, existing_label.label.span, "the other label is found here"
                     ));
+                }
+            }
             if scope.parent.is_none() {
                 break;
+            }
             scope_id = scope.parent.unwrap();
+        }
         // No collisions
         let scope = &mut ctx.heap[self.cur_scope];
         scope.labels.push(new_label_id);
         Ok(())
+    }
     /// Finds a particular labeled statement by its identifier. Once found it
     /// will make sure that the target label does not skip over any variable
     /// declarations within the scope in which the label was found.
     fn find_label(mut scope_id: ScopeId, ctx: &Ctx, identifier: &Identifier) -> Result<LabeledStatementId, ParseError> {
         loop {
             let scope = &ctx.heap[scope_id];
             let relative_scope_pos = scope.relative_pos_in_parent;
             for label_id in scope.labels.iter().copied() {
                 let label = &ctx.heap[label_id];
                 if label.label == *identifier {
                     // Found the target label, now make sure that the jump to
                     // the label doesn't imply a skipped variable declaration
                     for variable_id in scope.variables.iter().copied() {
                         // TODO: Better to do this in control flow analysis, it
                         //  is legal to skip over a variable declaration if it
                         //  is not actually being used.
                         let variable = &ctx.heap[variable_id];
                         if variable.relative_pos_in_parent > relative_scope_pos && variable.relative_pos_in_parent < label.relative_pos_in_parent {
                             return Err(
                                 ParseError::new_error_str_at_span(&ctx.module().source, identifier.span, "this target label skips over a variable declaration")
                                 .with_info_str_at_span(&ctx.module().source, label.label.span, "because it jumps to this label")
                                 .with_info_str_at_span(&ctx.module().source, variable.identifier.span, "which skips over this variable")
                             );
+                        }
+                    }
                     return Ok(label_id);
+                }
+            }
             if scope.parent.is_none() {
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, identifier.span, "could not find this label"
                 ));
+            }
             scope_id = scope.parent.unwrap();
+        }
+    }
     /// This function will check if the provided scope has a parent that belongs
     /// to a while statement.
     fn scope_is_nested_in_while_statement(mut scope_id: ScopeId, ctx: &Ctx, expected_while_id: WhileStatementId) -> bool {
         let while_stmt = &ctx.heap[expected_while_id];
         loop {
             let scope = &ctx.heap[scope_id];
             if scope.this == while_stmt.scope {
                 return true;
+            }
             match scope.parent {
                 Some(new_scope_id) => scope_id = new_scope_id,
                 None => return false, // walked all the way up, not encountering the while statement
+            }
+        }
+    }
     /// This function should be called while dealing with break/continue
     /// statements. It will try to find the targeted while statement, using the
     /// target label if provided. If a valid target is found then the loop's
     /// ID will be returned, otherwise a parsing error is constructed.
     /// The provided input position should be the position of the break/continue
     /// statement.
     fn resolve_break_or_continue_target(ctx: &Ctx, control_flow: &ControlFlowStatement, span: InputSpan, label: &Option<Identifier>) -> Result<WhileStatementId, ParseError> {
         let target = match label {
             Some(label) => {

src/protocol/parser/type_table.rs

➞

Show inline comments

 /**
  * type_table.rs
+ *
  * The type table is a lookup from AST definition (which contains just what the
  * programmer typed) to a type with additional information computed (e.g. the
  * byte size and offsets of struct members). The type table should be considered
  * the authoritative source of information on types by the compiler (not the
  * AST itself!).
+ *
  * The type table operates in two modes: one is where we just look up the type,
  * check its fields for correctness and mark whether it is polymorphic or not.
  * The second one is where we compute byte sizes, alignment and offsets.
+ *
  * The basic algorithm for type resolving and computing byte sizes is to
  * recursively try to lay out each member type of a particular type. This is
  * done in a stack-like fashion, where each embedded type pushes a breadcrumb
  * unto the stack. We may discover a cycle in embedded types (we call this a
  * "type loop"). After which the type table attempts to break the type loop by
  * making specific types heap-allocated. Upon doing so we know their size
  * because their stack-size is now based on pointers. Hence breaking the type
  * loop required for computing the byte size of types.
+ *
  * The reason for these type shenanigans is because PDL is a value-based
  * language, but we would still like to be able to express recursively defined
  * types like trees or linked lists. Hence we need to insert pointers somewhere
  * to break these cycles.
+ *
  * We will insert these pointers into the variants of unions. However note that
  * we can only compute the stack size of a union until we've looked at *all*
  * variants. Hence we perform an initial pass where we detect type loops, a
  * second pass where we compute the stack sizes of everything, and a third pass
  * where we actually compute the size of the heap allocations for unions.
+ *
  * As a final bit of global documentation: non-polymorphic types will always
  * have one "monomorph" entry. This contains the non-polymorphic type's memory
  * layout.
  */
 // Programmer note: deduplication of types is currently disabled, see the
 // @Deduplication key. Tests might fail when it is re-enabled.
 use std::collections::HashMap;
 use std::hash::{Hash, Hasher};
 use crate::protocol::ast::*;
 use crate::protocol::parser::symbol_table::SymbolScope;
 use crate::protocol::input_source::ParseError;
 use crate::protocol::parser::*;
 //------------------------------------------------------------------------------
 // Defined Types
 //------------------------------------------------------------------------------
 /// Struct wrapping around a potentially polymorphic type. If the type does not
 /// have any polymorphic arguments then it will not have any monomorphs and
 /// `is_polymorph` will be set to `false`. A type with polymorphic arguments
 /// only has `is_polymorph` set to `true` if the polymorphic arguments actually
 /// appear in the types associated types (function return argument, struct
 /// field, enum variant, etc.). Otherwise the polymorphic argument is just a
 /// marker and does not influence the bytesize of the type.
 #[allow(unused)]
 pub struct DefinedType {
     pub(crate) ast_root: RootId,
     pub(crate) ast_definition: DefinitionId,
     pub(crate) definition: DefinedTypeVariant,
     pub(crate) poly_vars: Vec<PolymorphicVariable>,
     pub(crate) is_polymorph: bool,
+}
 pub enum DefinedTypeVariant {
     Enum(EnumType),
     Union(UnionType),
     Struct(StructType),
     Procedure(ProcedureType),
+}
 impl DefinedTypeVariant {
     pub(crate) fn is_data_type(&self) -> bool {
         use DefinedTypeVariant as DTV;
         match self {
             DTV::Struct(_) | DTV::Enum(_) | DTV::Union(_) => return true,
             DTV::Procedure(_) => return false,
+        }
+    }
     pub(crate) fn as_struct(&self) -> &StructType {
         match self {
             DefinedTypeVariant::Struct(v) => v,
             _ => unreachable!()
+        }
+    }
     pub(crate) fn as_enum(&self) -> &EnumType {
         match self {
             DefinedTypeVariant::Enum(v) => v,
             _ => unreachable!()
+        }
+    }
     pub(crate) fn as_union(&self) -> &UnionType {
         match self {
             DefinedTypeVariant::Union(v) => v,
             _ => unreachable!()
+        }
+    }
+}
 pub struct PolymorphicVariable {
     pub(crate) identifier: Identifier,
     pub(crate) is_in_use: bool, // a polymorphic argument may be defined, but not used by the type definition
+}
 /// `EnumType` is the classical C/C++ enum type. It has various variants with
 /// an assigned integer value. The integer values may be user-defined,
 /// compiler-defined, or a mix of the two. If a user assigns the same enum
 /// value multiple times, we assume the user is an expert and we consider both
 /// variants to be equal to one another.
 pub struct EnumType {
     pub variants: Vec<EnumVariant>,
     pub minimum_tag_value: i64,
     pub maximum_tag_value: i64,
     pub tag_type: ConcreteType,
     pub size: usize,
     pub alignment: usize,
+}
 // TODO: Also support maximum u64 value
 pub struct EnumVariant {
     pub identifier: Identifier,
     pub value: i64,
+}
 /// `UnionType` is the algebraic datatype (or sum type, or discriminated union).
 /// A value is an element of the union, identified by its tag, and may contain
 /// a single subtype.
 /// For potentially infinite types (i.e. a tree, or a linked list) only unions
 /// can break the infinite cycle. So when we lay out these unions in memory we
 /// will reserve enough space on the stack for all union variants that do not
 /// cause "type loops" (i.e. a union `A` with a variant containing a struct
 /// `B`). And we will reserve enough space on the heap (and store a pointer in
 /// the union) for all variants which do cause type loops (i.e. a union `A`
 /// with a variant to a struct `B` that contains the union `A` again).
 pub struct UnionType {
     pub variants: Vec<UnionVariant>,
     pub tag_type: ConcreteType,
     pub tag_size: usize,
+}
 pub struct UnionVariant {
     pub identifier: Identifier,
     pub embedded: Vec<ParserType>, // zero-length does not have embedded values
     pub tag_value: i64,
+}
 /// `StructType` is a generic C-like struct type (or record type, or product
 /// type) type.
 pub struct StructType {
     pub fields: Vec<StructField>,
+}
 pub struct StructField {
     pub identifier: Identifier,
     pub parser_type: ParserType,
+}
 /// `ProcedureType` is the signature of a procedure/component
 pub struct ProcedureType {
     pub kind: ProcedureKind,
     pub return_type: Option<ParserType>,
     pub arguments: Vec<ProcedureArgument>,
+}
 pub struct ProcedureArgument {
     identifier: Identifier,
     parser_type: ParserType,
+}
 /// Represents the data associated with a single expression after type inference
 /// for a monomorph (or just the normal expression types, if dealing with a
 /// non-polymorphic function/component).
 pub struct MonomorphExpression {
     // The output type of the expression. Note that for a function it is not the
     // function's signature but its return type
     pub(crate) expr_type: ConcreteType,
     // Has multiple meanings: the field index for select expressions, the
     // monomorph index for polymorphic function calls or literals. Negative
     // values are never used, but used to catch programming errors.
     pub(crate) field_or_monomorph_idx: i32,
     pub(crate) type_id: TypeId,
+}
 //------------------------------------------------------------------------------
 // Type monomorph storage
 //------------------------------------------------------------------------------
 pub(crate) enum MonoTypeVariant {
     Builtin, // no extra data, added manually in compiler initialization code
     Enum, // no extra data
     Struct(StructMonomorph),
     Union(UnionMonomorph),
     Procedure(ProcedureMonomorph), // functions, components
     Tuple(TupleMonomorph),
+}
 impl MonoTypeVariant {
     fn as_struct_mut(&mut self) -> &mut StructMonomorph {
         match self {
             MonoTypeVariant::Struct(v) => v,
             _ => unreachable!(),
+        }
+    }
     pub(crate) fn as_union(&self) -> &UnionMonomorph {
         match self {
             MonoTypeVariant::Union(v) => v,
             _ => unreachable!(),
+        }
+    }
     fn as_union_mut(&mut self) -> &mut UnionMonomorph {
         match self {
             MonoTypeVariant::Union(v) => v,
             _ => unreachable!(),
+        }
+    }
     fn as_tuple_mut(&mut self) -> &mut TupleMonomorph {
         match self {
             MonoTypeVariant::Tuple(v) => v,
             _ => unreachable!(),
+        }
+    }
     pub(crate) fn as_procedure(&self) -> &ProcedureMonomorph {
         match self {
             MonoTypeVariant::Procedure(v) => v,
             _ => unreachable!(),
+        }
+    }
     fn as_procedure_mut(&mut self) -> &mut ProcedureMonomorph {
         match self {
             MonoTypeVariant::Procedure(v) => v,
             _ => unreachable!(),
+        }
+    }
+}
 /// Struct monomorph
 pub struct StructMonomorph {
     pub fields: Vec<StructMonomorphField>,
+}
 pub struct StructMonomorphField {
     pub type_id: TypeId,
     concrete_type: ConcreteType,
     pub size: usize,
     pub alignment: usize,
     pub offset: usize,
+}
 /// Union monomorph
 pub struct UnionMonomorph {
     pub variants: Vec<UnionMonomorphVariant>,
     pub tag_size: usize, // copied from `UnionType` upon monomorph construction.
     // note that the stack size is in the `TypeMonomorph` struct. This size and
     // alignment will include the size of the union tag.
     //
     // heap_size contains the allocated size of the union in the case it
     // is used to break a type loop. If it is 0, then it doesn't require
     // allocation and lives entirely on the stack.
     pub heap_size: usize,
     pub heap_alignment: usize,
+}
 pub struct UnionMonomorphVariant {
     pub lives_on_heap: bool,
     pub embedded: Vec<UnionMonomorphEmbedded>,
+}
 pub struct UnionMonomorphEmbedded {
     pub type_id: TypeId,
     concrete_type: ConcreteType,
     // Note that the meaning of the offset (and alignment) depend on whether or
     // not the variant lives on the stack/heap. If it lives on the stack then
     // they refer to the offset from the start of the union value (so the first
     // embedded type lives at a non-zero offset, because the union tag sits in
     // the front). If it lives on the heap then it refers to the offset from the
     // allocated memory region (so the first embedded type lives at a 0 offset).
     pub size: usize,
     pub alignment: usize,
     pub offset: usize,
+}
 /// Procedure (functions and components of all possible types) monomorph. Also
 /// stores the expression type data from the typechecking/inferencing pass.
 pub struct ProcedureMonomorph {
     pub monomorph_index: u32,
     pub builtin: bool,
+}
 /// Tuple monomorph. Again a kind of exception because one cannot define a named
 /// tuple type containing explicit polymorphic variables. But again: we need to
 /// store size/offset/alignment information, so we do it here.
 pub struct TupleMonomorph {
     pub members: Vec<TupleMonomorphMember>
+}
 pub struct TupleMonomorphMember {
     pub type_id: TypeId,
     concrete_type: ConcreteType,
     pub size: usize,
     pub alignment: usize,
     pub offset: usize,
+}
 /// Generic unique type ID. Every monomorphed type and every non-polymorphic
 /// type will have one of these associated with it.
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub struct TypeId(i64);
 impl TypeId {
     pub(crate) fn new_invalid() -> Self {
         return Self(-1);
+    }
+}
 /// A monomorphed type (or non-polymorphic type's) memory layout and information
 /// regarding associated types (like a struct's field type).
 pub struct MonoType {
     pub type_id: TypeId,
     pub concrete_type: ConcreteType,
     pub size: usize,
     pub alignment: usize,
     pub(crate) variant: MonoTypeVariant
+}
 impl MonoType {
     #[inline]
     fn new_empty(type_id: TypeId, concrete_type: ConcreteType, variant: MonoTypeVariant) -> Self {
         return Self {
             type_id, concrete_type,
             size: 0,
             alignment: 0,
             variant,
+        }
+    }
     /// Little internal helper function as a reminder: if alignment is 0, then
     /// the size/alignment are not actually computed yet!
     #[inline]
     fn get_size_alignment(&self) -> Option<(usize, usize)> {
         if self.alignment == 0 {
             return None
         } else {
             return Some((self.size, self.alignment));
+        }
+    }
+}
 /// Special structure that acts like the lookup key for `ConcreteType` instances
 /// that have already been added to the type table before.
 #[derive(Clone)]
 struct MonoSearchKey {
     // Uses bitflags to denote when parts between search keys should match and
     // whether they should be checked. Needs to have a system like this to
     // accommodate tuples.
     parts: Vec<(u8, ConcreteTypePart)>,
     change_bit: u8,
+}
 impl MonoSearchKey {
     const KEY_IN_USE: u8 = 0x01;
     const KEY_CHANGE_BIT: u8 = 0x02;
     fn with_capacity(capacity: usize) -> Self {
         return MonoSearchKey{
             parts: Vec::with_capacity(capacity),
             change_bit: 0,
         };
+    }
     /// Sets the search key based on a single concrete type and its polymorphic
     /// variables.
     fn set(&mut self, concrete_type_parts: &[ConcreteTypePart], poly_var_in_use: &[PolymorphicVariable]) {
         self.set_top_type(concrete_type_parts[0]);
         let mut poly_var_index = 0;
         for subtype in ConcreteTypeIter::new(concrete_type_parts, 0) {
             let in_use = poly_var_in_use[poly_var_index].is_in_use;
             poly_var_index += 1;
             self.push_subtype(subtype, in_use);
+        }
         debug_assert_eq!(poly_var_index, poly_var_in_use.len());
+    }
     /// Starts setting the search key based on an initial top-level type,
     /// programmer must call `push_subtype` the appropriate number of times
     /// after calling this function
     fn set_top_type(&mut self, type_part: ConcreteTypePart) {
         self.parts.clear();
         self.parts.push((Self::KEY_IN_USE, type_part));
         self.change_bit = Self::KEY_CHANGE_BIT;
+    }
     fn push_subtype(&mut self, concrete_type: &[ConcreteTypePart], in_use: bool) {
         let flag = self.change_bit | (if in_use { Self::KEY_IN_USE } else { 0 });
         for part in concrete_type {
             self.parts.push((flag, *part));
+        }
         self.change_bit ^= Self::KEY_CHANGE_BIT;
+    }
     fn push_subtree(&mut self, concrete_type: &[ConcreteTypePart], poly_var_in_use: &[PolymorphicVariable]) {
         self.parts.push((self.change_bit | Self::KEY_IN_USE, concrete_type[0]));
         self.change_bit ^= Self::KEY_CHANGE_BIT;
         let mut poly_var_index = 0;
         for subtype in ConcreteTypeIter::new(concrete_type, 0) {
             let in_use = poly_var_in_use[poly_var_index].is_in_use;
             poly_var_index += 1;
             self.push_subtype(subtype, in_use);
+        }
         debug_assert_eq!(poly_var_index, poly_var_in_use.len());
+    }
     // Utilities for hashing and comparison
     fn find_end_index(&self, start_index: usize) -> usize {
         // Check if we're already at the end
         let mut index = start_index;
         if index >= self.parts.len() {
             return index;
+        }
         // Iterate until bit flips, or until at end
         let expected_bit = self.parts[index].0 & Self::KEY_CHANGE_BIT;
         index += 1;
         while index < self.parts.len() {
             let current_bit = self.parts[index].0 & Self::KEY_CHANGE_BIT;
             if current_bit != expected_bit {
@@ @@ -1074,770 +1075,768 @@ impl TypeTable { @@
     ) -> Result<(), ParseError> {
         for (item_idx, item) in items.iter().enumerate() {
             let item_ident = getter(item);
             for other_item in &items[0..item_idx] {
                 let other_item_ident = getter(other_item);
                 if item_ident == other_item_ident {
                     let module_source = &modules[root_id.index as usize].source;
                     return Err(ParseError::new_error_at_span(
                         module_source, item_ident.span, format!("This {} is defined more than once", item_name)
                     ).with_info_at_span(
                         module_source, other_item_ident.span, format!("The other {} is defined here", item_name)
                     ));
+                }
+            }
+        }
         Ok(())
+    }
     /// Go through a list of polymorphic arguments and make sure that the
     /// arguments all have unique names, and the arguments do not conflict with
     /// any symbols defined at the module scope.
     fn check_poly_args_collision(
         modules: &[Module], ctx: &PassCtx, root_id: RootId, poly_args: &[Identifier]
     ) -> Result<(), ParseError> {
         // Make sure polymorphic arguments are unique and none of the
         // identifiers conflict with any imported scopes
         for (arg_idx, poly_arg) in poly_args.iter().enumerate() {
             for other_poly_arg in &poly_args[..arg_idx] {
                 if poly_arg == other_poly_arg {
                     let module_source = &modules[root_id.index as usize].source;
                     return Err(ParseError::new_error_str_at_span(
                         module_source, poly_arg.span,
                         "This polymorphic argument is defined more than once"
                     ).with_info_str_at_span(
                         module_source, other_poly_arg.span,
                         "It conflicts with this polymorphic argument"
                     ));
+                }
+            }
             // Check if identifier conflicts with a symbol defined or imported
             // in the current module
             if let Some(symbol) = ctx.symbols.get_symbol_by_name(SymbolScope::Module(root_id), poly_arg.value.as_bytes()) {
                 // We have a conflict
                 let module_source = &modules[root_id.index as usize].source;
                 let introduction_span = symbol.variant.span_of_introduction(ctx.heap);
                 return Err(ParseError::new_error_str_at_span(
                     module_source, poly_arg.span,
                     "This polymorphic argument conflicts with another symbol"
                 ).with_info_str_at_span(
                     module_source, introduction_span,
                     "It conflicts due to this symbol"
                 ));
+            }
+        }
         // All arguments are fine
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Detecting type loops
     //--------------------------------------------------------------------------
     /// Internal function that will detect type loops and check if they're
     /// resolvable. If so then the appropriate union variants will be marked as
     /// "living on heap". If not then a `ParseError` will be returned
     fn detect_and_resolve_type_loops_for(&mut self, modules: &[Module], heap: &Heap, arch: &TargetArch, concrete_type: ConcreteType) -> Result<(), ParseError> {
         // Programmer notes: what happens here is the we call
         // `check_member_for_type_loops` for a particular type's member, and
         // then take action using the return value:
         // 1. It might already be resolved: in this case it implies we don't
         //  have type loops, or they have been resolved.
         // 2. A new type is encountered. If so then it is added to the type loop
         //  breadcrumbs.
         // 3. A type loop is detected (implying the type is already resolved, or
         //  already exists in the type loop breadcrumbs).
         //
         // Using the breadcrumbs we incrementally check every member type of a
         // particular considered type (e.g. a struct field, tuple member), and
         // do the same as above. Note that when a breadcrumb is added we reserve
         // space in the monomorph storage, initialized to zero-values (i.e.
         // wrong values). The breadcrumbs keep track of how far and along we are
         // with resolving the member types.
         //
         // At the end we may have some type loops. If they're unresolvable then
         // we throw an error). If there are no type loops or they are all
         // resolvable then we end up with a list of `encountered_types`. These
         // are then used by `lay_out_memory_for_encountered_types`.
         debug_assert!(self.type_loop_breadcrumbs.is_empty());
         debug_assert!(self.type_loops.is_empty());
         debug_assert!(self.encountered_types.is_empty());
         // Push the initial breadcrumb
         let initial_breadcrumb = Self::check_member_for_type_loops(
             &self.type_loop_breadcrumbs, &self.definition_lookup, &self.mono_type_lookup,
             &mut self.mono_search_key, &concrete_type
         );
         if let TypeLoopResult::PushBreadcrumb(definition_id, concrete_type) = initial_breadcrumb {
             self.handle_new_breadcrumb_for_type_loops(arch, definition_id, concrete_type);
         } else {
             unreachable!()
         };
         // Enter into the main resolving loop
         while !self.type_loop_breadcrumbs.is_empty() {
             // Because we might be modifying the breadcrumb array we need to
             let breadcrumb_idx = self.type_loop_breadcrumbs.len() - 1;
             let mut breadcrumb = self.type_loop_breadcrumbs[breadcrumb_idx].clone();
             let mono_type = &self.mono_types[breadcrumb.type_id.0 as usize];
             let resolve_result = match &mono_type.variant {
                 MonoTypeVariant::Builtin => {
                     TypeLoopResult::TypeExists
+                }
                 MonoTypeVariant::Enum => {
                     TypeLoopResult::TypeExists
                 },
                 MonoTypeVariant::Union(monomorph) => {
                     let num_variants = monomorph.variants.len() as u32;
                     let mut union_result = TypeLoopResult::TypeExists;
                     'member_loop: while breadcrumb.next_member < num_variants {
                         let mono_variant = &monomorph.variants[breadcrumb.next_member as usize];
                         let num_embedded = mono_variant.embedded.len() as u32;
                         while breadcrumb.next_embedded < num_embedded {
                             let mono_embedded = &mono_variant.embedded[breadcrumb.next_embedded as usize];
                             union_result = Self::check_member_for_type_loops(
                                 &self.type_loop_breadcrumbs, &self.definition_lookup, &self.mono_type_lookup,
                                 &mut self.mono_search_key, &mono_embedded.concrete_type
                             );
                             if union_result != TypeLoopResult::TypeExists {
                                 // In type loop or new breadcrumb pushed, so
                                 // break out of the resolving loop
                                 break 'member_loop;
+                            }
                             breadcrumb.next_embedded += 1;
+                        }
                         breadcrumb.next_embedded = 0;
                         breadcrumb.next_member += 1
+                    }
                     union_result
                 },
                 MonoTypeVariant::Struct(monomorph) => {
                     let num_fields = monomorph.fields.len() as u32;
                     let mut struct_result = TypeLoopResult::TypeExists;
                     while breadcrumb.next_member < num_fields {
                         let mono_field = &monomorph.fields[breadcrumb.next_member as usize];
                         struct_result = Self::check_member_for_type_loops(
                             &self.type_loop_breadcrumbs, &self.definition_lookup, &self.mono_type_lookup,
                             &mut self.mono_search_key, &mono_field.concrete_type
                         );
                         if struct_result != TypeLoopResult::TypeExists {
                             // Type loop or breadcrumb pushed, so break out of
                             // the resolving loop
                             break;
+                        }
                         breadcrumb.next_member += 1;
+                    }
                     struct_result
                 },
                 MonoTypeVariant::Procedure(_) => unreachable!(),
                 MonoTypeVariant::Tuple(monomorph) => {
                     let num_members = monomorph.members.len() as u32;
                     let mut tuple_result = TypeLoopResult::TypeExists;
                     while breadcrumb.next_member < num_members {
                         let tuple_member = &monomorph.members[breadcrumb.next_member as usize];
                         tuple_result = Self::check_member_for_type_loops(
                             &self.type_loop_breadcrumbs, &self.definition_lookup, &self.mono_type_lookup,
                             &mut self.mono_search_key, &tuple_member.concrete_type
                         );
                         if tuple_result != TypeLoopResult::TypeExists {
                             break;
+                        }
                         breadcrumb.next_member += 1;
+                    }
                     tuple_result
+                }
             };
             // Handle the result of attempting to resolve the current breadcrumb
             match resolve_result {
                 TypeLoopResult::TypeExists => {
                     // We finished parsing the type
                     self.type_loop_breadcrumbs.pop();
                 },
                 TypeLoopResult::PushBreadcrumb(definition_id, concrete_type) => {
                     // We recurse into the member type.
                     self.type_loop_breadcrumbs[breadcrumb_idx] = breadcrumb;
                     self.handle_new_breadcrumb_for_type_loops(arch, definition_id, concrete_type);
                 },
                 TypeLoopResult::TypeLoop(first_idx) => {
                     // Because we will be modifying breadcrumbs within the
                     // type-loop handling code, put back the modified breadcrumb
                     self.type_loop_breadcrumbs[breadcrumb_idx] = breadcrumb;
                     // We're in a type loop. Add the type loop
                     let mut loop_members = Vec::with_capacity(self.type_loop_breadcrumbs.len() - first_idx);
                     let mut contains_union = false;
                     for breadcrumb_idx in first_idx..self.type_loop_breadcrumbs.len() {
                         let breadcrumb = &mut self.type_loop_breadcrumbs[breadcrumb_idx];
                         let mut is_union = false;
                         // Check if type loop member is a union that may be
                         // broken up by moving some of its members to the heap.
                         let mono_type = &mut self.mono_types[breadcrumb.type_id.0 as usize];
                         if let MonoTypeVariant::Union(union_type) = &mut mono_type.variant {
                             // Mark the variant that caused the loop as heap
                             // allocated to break the type loop.
                             let variant = &mut union_type.variants[breadcrumb.next_member as usize];
                             variant.lives_on_heap = true;
                             breadcrumb.next_embedded += 1;
                             is_union = true;
                             contains_union = true;
                         } // else: we don't care about the type for now
                         loop_members.push(TypeLoopEntry{
                             type_id: breadcrumb.type_id,
                             is_union
                         });
+                    }
                     let new_type_loop = TypeLoop{ members: loop_members };
                     if !contains_union {
                         // No way to (potentially) break the union. So return a
                         // type loop error. This is because otherwise our
                         // breadcrumb resolver ends up in an infinite loop.
                         return Err(construct_type_loop_error(
                             &self.mono_types, &new_type_loop, modules, heap
                         ));
+                    }
                     self.type_loops.push(new_type_loop);
+                }
+            }
+        }
         // All breadcrumbs have been cleared. So now `type_loops` contains all
         // of the encountered type loops, and `encountered_types` contains a
         // list of all unique monomorphs we encountered.
         // The next step is to figure out if all of the type loops can be
         // broken. A type loop can be broken if at least one union exists in the
         // loop and that union ended up having variants that are not part of
         // a type loop.
         fn type_loop_source_span_and_message<'a>(
             modules: &'a [Module], heap: &Heap, mono_types: &MonoTypeArray,
             definition_id: DefinitionId, mono_type_id: TypeId, index_in_loop: usize
         ) -> (&'a InputSource, InputSpan, String) {
             // Note: because we will discover the type loop the *first* time we
             // instantiate a monomorph with the provided polymorphic arguments
             // (not all arguments are actually used in the type). We don't have
             // to care about a second instantiation where certain unused
             // polymorphic arguments are different.
             let mono_type = &mono_types[mono_type_id.0 as usize];
             let type_name = mono_type.concrete_type.display_name(heap);
             let message = if index_in_loop == 0 {
                 format!(
                     "encountered an infinitely large type for '{}' (which can be fixed by \
                     introducing a union type that has a variant whose embedded types are \
                     not part of a type loop, or do not have embedded types)",
                     type_name
+                )
             } else if index_in_loop == 1 {
                 format!("because it depends on the type '{}'", type_name)
             } else {
                 format!("which depends on the type '{}'", type_name)
             };
             let ast_definition = &heap[definition_id];
             let ast_root_id = ast_definition.defined_in();
             return (
                 &modules[ast_root_id.index as usize].source,
                 ast_definition.identifier().span,
                 message
             );
+        }
         fn construct_type_loop_error(mono_types: &MonoTypeArray, type_loop: &TypeLoop, modules: &[Module], heap: &Heap) -> ParseError {
             // Seek first entry to produce parse error. Then continue builder
             // pattern. This is the error case so efficiency can go home.
             let mut parse_error = None;
             let mut next_member_index = 0;
             while next_member_index < type_loop.members.len() {
                 let first_entry = &type_loop.members[next_member_index];
                 next_member_index += 1;
                 // Retrieve definition of first type in loop
                 let first_mono_type = &mono_types[first_entry.type_id.0 as usize];
                 let first_definition_id = get_concrete_type_definition(&first_mono_type.concrete_type.parts);
                 if first_definition_id.is_none() {
                     continue;
+                }
                 let first_definition_id = first_definition_id.unwrap();
                 // Produce error message for first type in loop
                 let (first_module, first_span, first_message) = type_loop_source_span_and_message(
                     modules, heap, mono_types, first_definition_id, first_entry.type_id, 0
                 );
                 parse_error = Some(ParseError::new_error_at_span(first_module, first_span, first_message));
                 break;
+            }
             let mut parse_error = parse_error.unwrap(); // Loop above cannot have failed, because we must have a type loop, type loops cannot contain only unnamed types
             let mut error_counter = 1;
             for member_idx in next_member_index..type_loop.members.len() {
                 let entry = &type_loop.members[member_idx];
                 let mono_type = &mono_types[entry.type_id.0 as usize];
                 let definition_id = get_concrete_type_definition(&mono_type.concrete_type.parts);
                 if definition_id.is_none() {
                     continue;
+                }
                 let definition_id = definition_id.unwrap();
                 let (module, span, message) = type_loop_source_span_and_message(
                     modules, heap, mono_types, definition_id, entry.type_id, error_counter
                 );
                 parse_error = parse_error.with_info_at_span(module, span, message);
                 error_counter += 1;
+            }
             parse_error
+        }
         for type_loop in &self.type_loops {
             let mut can_be_broken = false;
             debug_assert!(!type_loop.members.is_empty());
             for entry in &type_loop.members {
                 if entry.is_union {
                     let mono_type = self.mono_types[entry.type_id.0 as usize].variant.as_union();
                     debug_assert!(!mono_type.variants.is_empty()); // otherwise it couldn't be part of the type loop
                     let has_stack_variant = mono_type.variants.iter().any(|variant| !variant.lives_on_heap);
                     if has_stack_variant {
                         can_be_broken = true;
                         break;
+                    }
+                }
+            }
             if !can_be_broken {
                 // Construct a type loop error
                 return Err(construct_type_loop_error(&self.mono_types, type_loop, modules, heap));
+            }
+        }
         // If here, then all type loops have been resolved and we can lay out
         // all of the members
         self.type_loops.clear();
         return Ok(());
+    }
     /// Checks if the specified type needs to be resolved (i.e. we need to push
     /// a breadcrumb), is already resolved (i.e. we can continue with the next
     /// member of the currently considered type) or is in the process of being
     /// resolved (i.e. we're in a type loop). Because of borrowing rules we
     /// don't do any modifications of internal types here. Hence: if we
     /// return `PushBreadcrumb` then call `handle_new_breadcrumb_for_type_loops`
     /// to take care of storing the appropriate types.
     fn check_member_for_type_loops(
         breadcrumbs: &[TypeLoopBreadcrumb], definition_map: &DefinitionMap, mono_type_map: &MonoTypeMap,
         mono_key: &mut MonoSearchKey, concrete_type: &ConcreteType
     ) -> TypeLoopResult {
         use ConcreteTypePart as CTP;
         // Depending on the type, lookup if the type has already been visited
         // (i.e. either already has its memory layed out, or is part of a type
         // loop because we've already visited the type)
         debug_assert!(!concrete_type.parts.is_empty());
         let definition_id = if let ConcreteTypePart::Instance(definition_id, _) = concrete_type.parts[0] {
             definition_id
         } else {
             DefinitionId::new_invalid()
         };
         Self::set_search_key_to_type(mono_key, definition_map, &concrete_type.parts);
         if let Some(type_id) = mono_type_map.get(mono_key).copied() {
             for (breadcrumb_idx, breadcrumb) in breadcrumbs.iter().enumerate() {
                 if breadcrumb.type_id == type_id {
                     return TypeLoopResult::TypeLoop(breadcrumb_idx);
+                }
+            }
             return TypeLoopResult::TypeExists;
+        }
         // Type is not yet known, so we need to insert it into the lookup and
         // push a new breadcrumb.
         return TypeLoopResult::PushBreadcrumb(definition_id, concrete_type.clone());
+    }
     /// Handles the `PushBreadcrumb` result for a `check_member_for_type_loops`
     /// call. Will preallocate entries in the monomorphed type storage (with
     /// all memory properties zeroed).
     fn handle_new_breadcrumb_for_type_loops(&mut self, arch: &TargetArch, definition_id: DefinitionId, concrete_type: ConcreteType) {
         use DefinedTypeVariant as DTV;
         use ConcreteTypePart as CTP;
         let mut is_union = false;
         let type_id = match &concrete_type.parts[0] {
             // Builtin types
             CTP::Void | CTP::Message | CTP::Bool |
             CTP::UInt8 | CTP::UInt16 | CTP::UInt32 | CTP::UInt64 |
             CTP::SInt8 | CTP::SInt16 | CTP::SInt32 | CTP::SInt64 |
             CTP::Character | CTP::String |
             CTP::Array | CTP::Slice | CTP::Input | CTP::Output | CTP::Pointer => {
                 // Insert the entry for the builtin type, we should be able to
                 // immediately "steal" the size from the preinserted builtins.
                 let base_type_id = match &concrete_type.parts[0] {
                     CTP::Void => arch.void_type_id,
                     CTP::Message => arch.message_type_id,
                     CTP::Bool => arch.bool_type_id,
                     CTP::UInt8 => arch.uint8_type_id,
                     CTP::UInt16 => arch.uint16_type_id,
                     CTP::UInt32 => arch.uint32_type_id,
                     CTP::UInt64 => arch.uint64_type_id,
                     CTP::SInt8 => arch.sint8_type_id,
                     CTP::SInt16 => arch.sint16_type_id,
                     CTP::SInt32 => arch.sint32_type_id,
                     CTP::SInt64 => arch.sint64_type_id,
                     CTP::Character => arch.char_type_id,
                     CTP::String => arch.string_type_id,
                     CTP::Array => arch.array_type_id,
                     CTP::Slice => arch.slice_type_id,
                     CTP::Input => arch.input_type_id,
                     CTP::Output => arch.output_type_id,
                     CTP::Pointer => arch.pointer_type_id,
                     _ => unreachable!(),
                 };
                 let base_type = &self.mono_types[base_type_id.0 as usize];
                 let base_type_size = base_type.size;
                 let base_type_alignment = base_type.alignment;
                 let type_id = TypeId(self.mono_types.len() as i64);
                 Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
                 self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
                 self.mono_types.push(MonoType{
                     type_id,
                     concrete_type,
                     size: base_type_size,
                     alignment: base_type_alignment,
                     variant: MonoTypeVariant::Builtin
                 });
                 type_id
             },
             // User-defined types
             CTP::Tuple(num_embedded) => {
                 debug_assert!(definition_id.is_invalid()); // because tuples do not have an associated `DefinitionId`
                 let mut members = Vec::with_capacity(*num_embedded as usize);
                 for section in ConcreteTypeIter::new(&concrete_type.parts, 0) {
                     members.push(TupleMonomorphMember{
                         type_id: TypeId::new_invalid(),
                         concrete_type: ConcreteType{ parts: Vec::from(section) },
                         size: 0,
                         alignment: 0,
                         offset: 0
                     });
+                }
                 let type_id = TypeId(self.mono_types.len() as i64);
                 Self::set_search_key_to_tuple(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
                 self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
                 self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Tuple(TupleMonomorph{ members })));
                 type_id
             },
             CTP::Instance(_check_definition_id, _) => {
                 debug_assert_eq!(definition_id, *_check_definition_id); // because this is how `definition_id` was determined
                 Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
                 let base_type = self.definition_lookup.get(&definition_id).unwrap();
                 let type_id = match &base_type.definition {
                     DTV::Enum(definition) => {
                         // The enum is a bit exceptional in that when we insert
                         // it we we will immediately set its size/alignment:
                         // there is nothing to compute here.
                         debug_assert!(definition.size != 0 && definition.alignment != 0);
                         let type_id = TypeId(self.mono_types.len() as i64);
                         self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
                         self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Enum));
                         let mono_type = &mut self.mono_types[type_id.0 as usize];
                         mono_type.size = definition.size;
                         mono_type.alignment = definition.alignment;
                         type_id
                     },
                     DTV::Union(definition) => {
                         // Create all the variants with their concrete types
                         let mut mono_variants = Vec::with_capacity(definition.variants.len());
                         for poly_variant in &definition.variants {
                             let mut mono_embedded = Vec::with_capacity(poly_variant.embedded.len());
                             for poly_embedded in &poly_variant.embedded {
                                 let mono_concrete = Self::construct_concrete_type(poly_embedded, &concrete_type);
                                 mono_embedded.push(UnionMonomorphEmbedded{
                                     type_id: TypeId::new_invalid(),
                                     concrete_type: mono_concrete,
                                     size: 0,
                                     alignment: 0,
                                     offset: 0
                                 });
+                            }
                             mono_variants.push(UnionMonomorphVariant{
                                 lives_on_heap: false,
                                 embedded: mono_embedded,
                             })
+                        }
                         let type_id = TypeId(self.mono_types.len() as i64);
                         let tag_size = definition.tag_size;
                         Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
                         self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
                         self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Union(UnionMonomorph{
                             variants: mono_variants,
                             tag_size,
                             heap_size: 0,
                             heap_alignment: 0,
                         })));
                         is_union = true;
                         type_id
                     },
                     DTV::Struct(definition) => {
                         // Create fields
                         let mut mono_fields = Vec::with_capacity(definition.fields.len());
                         for poly_field in &definition.fields {
                             let mono_concrete = Self::construct_concrete_type(&poly_field.parser_type, &concrete_type);
                             mono_fields.push(StructMonomorphField{
                                 type_id: TypeId::new_invalid(),
                                 concrete_type: mono_concrete,
                                 size: 0,
                                 alignment: 0,
                                 offset: 0
                             })
+                        }
                         let type_id = TypeId(self.mono_types.len() as i64);
                         Self::set_search_key_to_type(&mut self.mono_search_key, &self.definition_lookup, &concrete_type.parts);
                         self.mono_type_lookup.insert(self.mono_search_key.clone(), type_id);
                         self.mono_types.push(MonoType::new_empty(type_id, concrete_type, MonoTypeVariant::Struct(StructMonomorph{
                             fields: mono_fields,
                         })));
                         type_id
                     },
                     DTV::Procedure(_) => {
                         unreachable!("pushing type resolving breadcrumb for procedure type")
                     },
                 };
                 type_id
             },
             CTP::Function(_, _) | CTP::Component(_, _) => todo!("function pointers"),
         };
         self.encountered_types.push(TypeLoopEntry{ type_id, is_union });
         self.type_loop_breadcrumbs.push(TypeLoopBreadcrumb{
             type_id,
             next_member: 0,
             next_embedded: 0,
         });
+    }
     /// Constructs a concrete type out of a parser type for a struct field or
     /// union embedded type. It will do this by looking up the polymorphic
     /// variables in the supplied concrete type. The assumption is that the
     /// polymorphic variable's indices correspond to the subtrees in the
     /// concrete type.
     fn construct_concrete_type(member_type: &ParserType, container_type: &ConcreteType) -> ConcreteType {
         use ParserTypeVariant as PTV;
         use ConcreteTypePart as CTP;
         // TODO: Combine with code in pass_typing.rs
         fn parser_to_concrete_part(part: &ParserTypeVariant) -> Option<ConcreteTypePart> {
             match part {
                 PTV::Void      => Some(CTP::Void),
                 PTV::Message   => Some(CTP::Message),
                 PTV::Bool      => Some(CTP::Bool),
                 PTV::UInt8     => Some(CTP::UInt8),
                 PTV::UInt16    => Some(CTP::UInt16),
                 PTV::UInt32    => Some(CTP::UInt32),
                 PTV::UInt64    => Some(CTP::UInt64),
                 PTV::SInt8     => Some(CTP::SInt8),
                 PTV::SInt16    => Some(CTP::SInt16),
                 PTV::SInt32    => Some(CTP::SInt32),
                 PTV::SInt64    => Some(CTP::SInt64),
                 PTV::Character => Some(CTP::Character),
                 PTV::String    => Some(CTP::String),
                 PTV::Array     => Some(CTP::Array),
                 PTV::Input     => Some(CTP::Input),
                 PTV::Output    => Some(CTP::Output),
                 PTV::Tuple(num) => Some(CTP::Tuple(*num)),
                 PTV::Definition(definition_id, num) => Some(CTP::Instance(*definition_id, *num)),
                 _              => None
+            }
+        }
         let mut parts = Vec::with_capacity(member_type.elements.len()); // usually a correct estimation, might not be
         for member_part in &member_type.elements {
             // Check if we have a regular builtin type
             if let Some(part) = parser_to_concrete_part(&member_part.variant) {
                 parts.push(part);
                 continue;
+            }
             // Not builtin, but if all code is working correctly, we only care
             // about the polymorphic argument at this point.
             if let PTV::PolymorphicArgument(_container_definition_id, poly_arg_idx) = member_part.variant {
                 debug_assert_eq!(_container_definition_id, get_concrete_type_definition(&container_type.parts).unwrap());
                 let mut container_iter = container_type.embedded_iter(0);
                 for _ in 0..poly_arg_idx {
                     container_iter.next();
+                }
                 let poly_section = container_iter.next().unwrap();
                 parts.extend(poly_section);
                 continue;
+            }
             unreachable!("unexpected type part {:?} from {:?}", member_part, member_type);
+        }
         return ConcreteType{ parts };
+    }
     //--------------------------------------------------------------------------
     // Determining memory layout for types
     //--------------------------------------------------------------------------
     /// Should be called after type loops are detected (and resolved
     /// successfully). As a result of this call we expect the
     /// `encountered_types` array to be filled. We'll calculate size/alignment/
     /// offset values for those types in this routine.
     fn lay_out_memory_for_encountered_types(&mut self, arch: &TargetArch) {
         // Programmers note: this works like a little stack machine. We have
         // memory layout breadcrumbs which, like the type loop breadcrumbs, keep
         // track of the currently considered member type. This breadcrumb also
         // stores an index into the `size_alignment_stack`, which will be used
         // to store intermediate size/alignment pairs until all members are
         // resolved. Note that this `size_alignment_stack` is NOT an
         // optimization, we're working around borrowing rules here.
         // Just finished type loop detection, so we're left with the encountered
         // types only. If we don't have any (a builtin type's monomorph was
         // added to the type table) then this function shouldn't be called at
         // all.
         debug_assert!(self.type_loops.is_empty());
         debug_assert!(!self.encountered_types.is_empty());
         debug_assert!(self.memory_layout_breadcrumbs.is_empty());
         debug_assert!(self.size_alignment_stack.is_empty());
         let (ptr_size, ptr_align) = self.mono_types[arch.pointer_type_id.0 as usize].get_size_alignment().unwrap();
         // Push the first entry (the type we originally started with when we
         // were detecting type loops)
         let first_entry = &self.encountered_types[0];
         self.memory_layout_breadcrumbs.push(MemoryBreadcrumb{
             type_id: first_entry.type_id,
             next_member: 0,
             next_embedded: 0,
             first_size_alignment_idx: 0,
         });
         // Enter the main resolving loop
         'breadcrumb_loop: while !self.memory_layout_breadcrumbs.is_empty() {
             let cur_breadcrumb_idx = self.memory_layout_breadcrumbs.len() - 1;
             let mut breadcrumb = self.memory_layout_breadcrumbs[cur_breadcrumb_idx].clone();
             let mono_type = &self.mono_types[breadcrumb.type_id.0 as usize];
             match &mono_type.variant {
                 MonoTypeVariant::Builtin | MonoTypeVariant::Enum => {
                     // Size should already be computed
                     dbg_code!({
                         let mono_type = &self.mono_types[breadcrumb.type_id.0 as usize];
                         debug_assert!(mono_type.size != 0 && mono_type.alignment != 0);
                     });
                 },
                 MonoTypeVariant::Union(mono_type) => {
                     // Retrieve size/alignment of each embedded type. We do not
                     // compute the offsets or total type sizes yet.
                     let num_variants = mono_type.variants.len() as u32;
                     while breadcrumb.next_member < num_variants {
                         let mono_variant = &mono_type.variants[breadcrumb.next_member as usize];
                         if mono_variant.lives_on_heap {
                             // To prevent type loops we made this a heap-
                             // allocated variant. This implies we cannot
                             // compute sizes of members at this point.
                         } else {
                             let num_embedded = mono_variant.embedded.len() as u32;
                             while breadcrumb.next_embedded < num_embedded {
                                 let mono_embedded = &mono_variant.embedded[breadcrumb.next_embedded as usize];
                                 let layout_result = Self::get_memory_layout_or_breadcrumb(
                                     &self.definition_lookup, &self.mono_type_lookup, &self.mono_types,
                                     &mut self.mono_search_key, arch, &mono_embedded.concrete_type.parts,
                                     self.size_alignment_stack.len()
                                 );
                                 match layout_result {
                                     MemoryLayoutResult::TypeExists(size, alignment) => {
                                         self.size_alignment_stack.push((size, alignment));
                                     },
                                     MemoryLayoutResult::PushBreadcrumb(new_breadcrumb) => {
                                         self.memory_layout_breadcrumbs[cur_breadcrumb_idx] = breadcrumb;
                                         self.memory_layout_breadcrumbs.push(new_breadcrumb);
                                         continue 'breadcrumb_loop;
+                                    }
+                                }
                                 breadcrumb.next_embedded += 1;
+                            }
+                        }
                         breadcrumb.next_member += 1;
                         breadcrumb.next_embedded = 0;
+                    }
                     // If here then we can at least compute the stack size of
                     // the type, we'll have to come back at the very end to
                     // fill in the heap size/alignment/offset of each heap-
                     // allocated variant.
                     let mut max_size = mono_type.tag_size;
                     let mut max_alignment = mono_type.tag_size;
                     let mono_type = &mut self.mono_types[breadcrumb.type_id.0 as usize];
                     let union_type = mono_type.variant.as_union_mut();
                     let mut size_alignment_idx = breadcrumb.first_size_alignment_idx as usize;
                     for variant in &mut union_type.variants {
                         // We're doing stack computations, so always start with
                         // the tag size/alignment.
                         let mut variant_offset = union_type.tag_size;
                         let mut variant_alignment = union_type.tag_size;
                         if variant.lives_on_heap {
                             // Variant lives on heap, so just a pointer
                             align_offset_to(&mut variant_offset, ptr_align);
                             variant_offset += ptr_size;
                             variant_alignment = variant_alignment.max(ptr_align);
                         } else {
                             // Variant lives on stack, so walk all embedded
                             // types.
                             for embedded in &mut variant.embedded {
                                 let (size, alignment) = self.size_alignment_stack[size_alignment_idx];

src/runtime/scheduler.rs

➞

Show inline comments

@@ @@ -29,773 +29,773 @@ pub(crate) struct Scheduler { @@
 impl Scheduler {
     pub fn new(runtime: Arc<RuntimeInner>, scheduler_id: u32) -> Self {
         return Self{ runtime, scheduler_id };
+    }
     pub fn run(&mut self) {
         // Setup global storage and workspaces that are reused for every
         // connector that we run
         'thread_loop: loop {
             // Retrieve a unit of work
             self.debug("Waiting for work");
             let connector_key = self.runtime.wait_for_work();
             if connector_key.is_none() {
                 // We should exit
                 self.debug(" ... No more work, quitting");
                 break 'thread_loop;
+            }
             // We have something to do
             let connector_key = connector_key.unwrap();
             let connector_id = connector_key.downcast();
             self.debug_conn(connector_id, &format!(" ... Got work, running {}", connector_key.index));
             let scheduled = self.runtime.get_component_private(&connector_key);
             // Keep running until we should no longer immediately schedule the
             // connector.
             let mut cur_schedule = ConnectorScheduling::Immediate;
             while let ConnectorScheduling::Immediate = cur_schedule {
                 self.handle_inbox_messages(scheduled);
                 // Run the main behaviour of the connector, depending on its
                 // current state.
                 if scheduled.shutting_down {
                     // Nothing to do. But we're stil waiting for all our pending
                     // control messages to be answered.
                     self.debug_conn(connector_id, &format!("Shutting down, {} Acks remaining", scheduled.router.num_pending_acks()));
                     if scheduled.router.num_pending_acks() == 0 {
                         // We're actually done, we can safely destroy the
                         // currently running connector
                         self.runtime.initiate_component_destruction(connector_key);
                         continue 'thread_loop;
                     } else {
                         cur_schedule = ConnectorScheduling::NotNow;
+                    }
                 } else {
                     self.debug_conn(connector_id, "Running ...");
                     let scheduler_ctx = SchedulerCtx{ runtime: &*self.runtime };
                     let new_schedule = scheduled.connector.run(scheduler_ctx, &mut scheduled.ctx);
                     self.debug_conn(connector_id, &format!("Finished running (new scheduling is {:?})", new_schedule));
                     // Handle all of the output from the current run: messages to
                     // send and connectors to instantiate.
                     self.handle_changes_in_context(scheduled);
                     cur_schedule = new_schedule;
+                }
+            }
             // If here then the connector does not require immediate execution.
             // So enqueue it if requested, and otherwise put it in a sleeping
             // state.
             match cur_schedule {
                 ConnectorScheduling::Immediate => unreachable!(),
                 ConnectorScheduling::Later => {
                     // Simply queue it again later
                     self.runtime.push_work(connector_key);
                 },
                 ConnectorScheduling::NotNow => {
                     // Need to sleep, note that we are the only ones which are
                     // allows to set the sleeping state to `true`, and since
                     // we're running it must currently be `false`.
                     self.try_go_to_sleep(connector_key, scheduled);
                 },
                 ConnectorScheduling::Exit => {
                     // Prepare for exit. Set the shutdown flag and broadcast
                     // messages to notify peers of closing channels
                     scheduled.shutting_down = true;
                     for port in &scheduled.ctx.ports {
                         if port.state != PortState::Closed {
                             let message = scheduled.router.prepare_closing_channel(
                                 port.self_id, port.peer_id,
                                 connector_id
                             );
                             self.debug_conn(connector_id, &format!("Sending message to {:?} [ exit ] \n --- {:?}", port.peer_connector, message));
                             self.runtime.send_message_assumed_alive(port.peer_connector, Message::Control(message));
+                        }
+                    }
                     // Any messages still in the public inbox should be handled
                     scheduled.ctx.inbox.clear_read_messages();
                     while let Some(ticket) = scheduled.ctx.get_next_message_ticket_even_if_not_in_sync() {
                         let message = scheduled.ctx.take_message_using_ticket(ticket);
                         self.handle_message_while_shutting_down(message, scheduled);
+                    }
                     if scheduled.router.num_pending_acks() == 0 {
                         // All ports (if any) already closed
                         self.runtime.initiate_component_destruction(connector_key);
                         continue 'thread_loop;
+                    }
                     self.try_go_to_sleep(connector_key, scheduled);
                 },
+            }
+        }
+    }
     /// Receiving messages from the public inbox and handling them or storing
     /// them in the component's private inbox
     fn handle_inbox_messages(&mut self, scheduled: &mut ScheduledConnector) {
         let connector_id = scheduled.ctx.id;
         while let Some(message) = scheduled.public.inbox.take_message() {
             // Check if the message has to be rerouted because we have moved the
             // target port to another component.
             self.debug_conn(connector_id, &format!("Handling message\n --- {:#?}", message));
             if let Some(target_port) = message.target_port() {
                 if let Some(other_component_id) = scheduled.router.should_reroute(target_port) {
                     self.debug_conn(connector_id, " ... Rerouting the message");
                     // We insert directly into the private inbox. Since we have
                     // a reroute entry the component can not yet be running.
                     if let Message::Control(_) = &message {
                         self.runtime.send_message_assumed_alive(other_component_id, message);
                     } else {
                         let key = unsafe { ConnectorKey::from_id(other_component_id) };
                         let component = self.runtime.get_component_private(&key);
                         component.ctx.inbox.insert_new(message);
+                    }
                     continue;
+                }
                 match scheduled.ctx.get_port_by_id(target_port) {
                     Some(port_info) => {
                         if port_info.state == PortState::Closed {
                             // We're no longer supposed to receive messages
                             // (rerouted message arrived much later!)
                             continue
+                        }
                     },
                     None => {
                         // Apparently we no longer have a handle to the port
                         continue;
+                    }
+                }
+            }
             // If here, then we should handle the message
             self.debug_conn(connector_id, " ... Handling the message");
             if let Message::Control(message) = &message {
                 match message.content {
                     ControlContent::PortPeerChanged(port_id, new_target_connector_id) => {
                         // Need to change port target
                         let port = scheduled.ctx.get_port_mut_by_id(port_id).unwrap();
                         port.peer_connector = new_target_connector_id;
                         // Note: for simplicity we program the scheduler to always finish
                         // running a connector with an empty outbox. If this ever changes
                         // then accepting the "port peer changed" message implies we need
                         // to change the recipient of the message in the outbox.
                         debug_assert!(scheduled.ctx.outbox.is_empty());
                         // And respond with an Ack
                         let ack_message = Message::Control(ControlMessage {
                             id: message.id,
                             sending_component_id: connector_id,
                             content: ControlContent::Ack,
                         });
                         self.debug_conn(connector_id, &format!("Sending message to {:?} [pp ack]\n --- {:?}", message.sending_component_id, ack_message));
                         self.runtime.send_message_assumed_alive(message.sending_component_id, ack_message);
                     },
                     ControlContent::CloseChannel(port_id) => {
                         // Mark the port as being closed
                         let port = scheduled.ctx.get_port_mut_by_id(port_id).unwrap();
                         port.state = PortState::Closed;
                         // Send an Ack
                         let ack_message = Message::Control(ControlMessage {
                             id: message.id,
                             sending_component_id: connector_id,
                             content: ControlContent::Ack,
                         });
                         self.debug_conn(connector_id, &format!("Sending message to {:?} [cc ack] \n --- {:?}", message.sending_component_id, ack_message));
                         self.runtime.send_message_assumed_alive(message.sending_component_id, ack_message);
                     },
                     ControlContent::Ack => {
                         if let Some(component_key) = scheduled.router.handle_ack(message.id) {
                             self.runtime.push_work(component_key);
                         };
                     },
                     ControlContent::Ping => {},
+                }
             } else {
                 // Not a control message
                 if scheduled.shutting_down {
                     // Since we're shutting down, we just want to respond with a
                     // message saying the message did not arrive.
                     debug_assert!(scheduled.ctx.inbox.get_next_message_ticket().is_none()); // public inbox should be completely cleared
                     self.handle_message_while_shutting_down(message, scheduled);
                 } else {
                     scheduled.ctx.inbox.insert_new(message);
+                }
+            }
+        }
+    }
     fn handle_message_while_shutting_down(&mut self, message: Message, scheduled: &mut ScheduledConnector) {
         let target_port_and_round_number = match message {
             Message::Data(msg) => Some((msg.data_header.target_port, msg.sync_header.sync_round)),
             Message::SyncComp(_) => None,
             Message::SyncPort(msg) => Some((msg.target_port, msg.sync_header.sync_round)),
             Message::SyncControl(_) => None,
             Message::Control(_) => None,
         };
         if let Some((target_port, sync_round)) = target_port_and_round_number {
             // This message is aimed at a port, but we're shutting down, so
             // notify the peer that its was not received properly.
             // (also: since we're shutting down, we're not in sync mode and
             // the context contains the definitive set of owned ports)
             let port = scheduled.ctx.get_port_by_id(target_port).unwrap();
             if port.state == PortState::Open {
                 let message = SyncControlMessage {
                     in_response_to_sync_round: sync_round,
                     target_component_id: port.peer_connector,
                     content: SyncControlContent::ChannelIsClosed(port.peer_id),
                 };
                 self.debug_conn(scheduled.ctx.id, &format!("Sending message to {:?} [shutdown]\n --- {:?}", port.peer_connector, message));
                 self.runtime.send_message_assumed_alive(port.peer_connector, Message::SyncControl(message));
+            }
+        }
+    }
     /// Handles changes to the context that were made by the component. This is
     /// the way (due to Rust's borrowing rules) that we bubble up changes in the
     /// component's state that the scheduler needs to know about (e.g. a message
     /// that the component wants to send, a port that has been added).
     fn handle_changes_in_context(&mut self, scheduled: &mut ScheduledConnector) {
         let connector_id = scheduled.ctx.id;
         // Handling any messages that were sent
         while let Some(message) = scheduled.ctx.outbox.pop_front() {
             let (target_component_id, over_port) = match &message {
                 Message::Data(content) => {
                     // Data messages are always sent to a particular port, and
                     // may end up being rerouted.
                     let port_desc = scheduled.ctx.get_port_by_id(content.data_header.sending_port).unwrap();
                     debug_assert_eq!(port_desc.peer_id, content.data_header.target_port);
                     debug_assert_eq!(port_desc.state, PortState::Open); // checked when adding to context
                     (port_desc.peer_connector, true)
                 },
                 Message::SyncComp(content) => {
                     // Sync messages are always sent to a particular component,
                     // the sender must make sure it actually wants to send to
                     // the specified component (and is not using an inconsistent
                     // component ID associated with a port).
                     (content.target_component_id, false)
                 },
                 Message::SyncPort(content) => {
                     let port_desc = scheduled.ctx.get_port_by_id(content.source_port).unwrap();
                     debug_assert_eq!(port_desc.peer_id, content.target_port);
                     debug_assert_eq!(port_desc.state, PortState::Open); // checked when adding to context
                     (port_desc.peer_connector, true)
                 },
                 Message::SyncControl(_) => unreachable!("component sending 'SyncControl' messages directly"),
                 Message::Control(_) => unreachable!("component sending 'Control' messages directly"),
             };
             self.debug_conn(connector_id, &format!("Sending message to {:?} [outbox, over port: {}] \n --- {:#?}", target_component_id, over_port, message));
             if over_port {
                 self.runtime.send_message_assumed_alive(target_component_id, message);
             } else {
                 self.runtime.send_message_maybe_destroyed(target_component_id, message);
+            }
+        }
         while let Some(state_change) = scheduled.ctx.state_changes.pop_front() {
             match state_change {
                 ComponentStateChange::CreatedComponent(component, initial_ports) => {
                     // Creating a new component. Need to relinquish control of
                     // the ports.
                     let new_component_key = self.runtime.create_pdl_component(component, false);
                     let new_connector = self.runtime.get_component_private(&new_component_key);
                     // First pass: transfer ports and the associated messages,
                     // also count the number of ports that have peers
                     let mut num_peers = 0;
                     for port_id in initial_ports {
                         // Transfer messages associated with the transferred port
                         scheduled.ctx.inbox.transfer_messages_for_port(port_id, &mut new_connector.ctx.inbox);
                         // Transfer the port itself
                         let port_index = scheduled.ctx.ports.iter()
                             .position(|v| v.self_id == port_id)
                             .unwrap();
                         let port = scheduled.ctx.ports.remove(port_index);
                         new_connector.ctx.ports.push(port.clone());
                         if port.state == PortState::Open {
                             num_peers += 1;
+                        }
+                    }
                     if num_peers == 0 {
                         // No peers to notify, so just schedule the component
                         self.runtime.push_work(new_component_key);
                     } else {
                         // Some peers to notify
                         let new_component_id = new_component_key.downcast();
                         let control_id = scheduled.router.prepare_new_component(new_component_key);
                         for port in new_connector.ctx.ports.iter() {
                             if port.state == PortState::Closed {
                                 continue;
+                            }
                             let control_message = scheduled.router.prepare_changed_port_peer(
                                 control_id, scheduled.ctx.id,
                                 port.peer_connector, port.peer_id,
                                 new_component_id, port.self_id
                             );
                             self.debug_conn(connector_id, &format!("Sending message to {:?} [newcom]\n --- {:#?}", port.peer_connector, control_message));
                             self.runtime.send_message_assumed_alive(port.peer_connector, Message::Control(control_message));
+                        }
+                    }
                 },
                 ComponentStateChange::CreatedPort(port) => {
                     scheduled.ctx.ports.push(port);
                 },
                 ComponentStateChange::ChangedPort(port_change) => {
                     if port_change.is_acquired {
                         scheduled.ctx.ports.push(port_change.port);
                     } else {
                         let index = scheduled.ctx.ports
                             .iter()
                             .position(|v| v.self_id == port_change.port.self_id)
                             .unwrap();
                         scheduled.ctx.ports.remove(index);
+                    }
+                }
+            }
+        }
         // Finally, check if we just entered or just left a sync region
         if scheduled.ctx.changed_in_sync {
             if scheduled.ctx.is_in_sync {
                 // Just entered sync region
             } else {
                 // Just left sync region. So prepare inbox for the next sync
                 // round
                 scheduled.ctx.inbox.clear_read_messages();
+            }
             scheduled.ctx.changed_in_sync = false; // reset flag
+        }
+    }
     fn try_go_to_sleep(&self, connector_key: ConnectorKey, connector: &mut ScheduledConnector) {
         debug_assert_eq!(connector_key.index, connector.ctx.id.index);
         debug_assert_eq!(connector.public.sleeping.load(Ordering::Acquire), false);
         // This is the running connector, and only the running connector may
         // decide it wants to sleep again.
         connector.public.sleeping.store(true, Ordering::Release);
         // But due to reordering we might have received messages from peers who
         // did not consider us sleeping. If so, then we wake ourselves again.
         if !connector.public.inbox.is_empty() {
             // Try to wake ourselves up (needed because someone might be trying
             // the exact same atomic compare-and-swap at this point in time)
             let should_wake_up_again = connector.public.sleeping
                 .compare_exchange(true, false, Ordering::SeqCst, Ordering::Acquire)
                 .is_ok();
             if should_wake_up_again {
                 self.runtime.push_work(connector_key)
+            }
+        }
+    }
-    fn debug(&self, message: &str) {
+    fn debug(&self, _message: &str) {
         // println!("DEBUG [thrd:{:02} conn:  ]: {}", self.scheduler_id, message);
+    }
-    fn debug_conn(&self, conn: ConnectorId, message: &str) {
+    fn debug_conn(&self, _conn: ConnectorId, _message: &str) {
         // println!("DEBUG [thrd:{:02} conn:{:02}]: {}", self.scheduler_id, conn.index, message);
+    }
+}
 // -----------------------------------------------------------------------------
 // ComponentCtx
 // -----------------------------------------------------------------------------
 enum ComponentStateChange {
     CreatedComponent(ConnectorPDL, Vec<PortIdLocal>),
     CreatedPort(Port),
     ChangedPort(ComponentPortChange),
+}
 #[derive(Clone)]
 pub(crate) struct ComponentPortChange {
     pub is_acquired: bool, // otherwise: released
     pub port: Port,
+}
 /// The component context (better name may be invented). This was created
 /// because part of the component's state is managed by the scheduler, and part
 /// of it by the component itself. When the component starts a sync block or
 /// exits a sync block the partially managed state by both component and
 /// scheduler need to be exchanged.
 pub(crate) struct ComponentCtx {
     // Mostly managed by the scheduler
     pub(crate) id: ConnectorId,
     ports: Vec<Port>,
     inbox: Inbox,
     // Submitted by the component
     is_in_sync: bool,
     changed_in_sync: bool,
     outbox: VecDeque<Message>,
     state_changes: VecDeque<ComponentStateChange>,
     // Workspaces that may be used by components to (generally) prevent
     // allocations. Be a good scout and leave it empty after you've used it.
     // TODO: Move to scheduler ctx, this is the wrong place
     pub workspace_ports: Vec<PortIdLocal>,
     pub workspace_branches: Vec<BranchId>,
+}
 impl ComponentCtx {
     pub(crate) fn new_empty() -> Self {
         return Self{
             id: ConnectorId::new_invalid(),
             ports: Vec::new(),
             inbox: Inbox::new(),
             is_in_sync: false,
             changed_in_sync: false,
             outbox: VecDeque::new(),
             state_changes: VecDeque::new(),
             workspace_ports: Vec::new(),
             workspace_branches: Vec::new(),
         };
+    }
     /// Notify the runtime that the component has created a new component. May
     /// only be called outside of a sync block.
     pub(crate) fn push_component(&mut self, component: ConnectorPDL, initial_ports: Vec<PortIdLocal>) {
         debug_assert!(!self.is_in_sync);
         self.state_changes.push_back(ComponentStateChange::CreatedComponent(component, initial_ports));
+    }
     /// Notify the runtime that the component has created a new port. May only
     /// be called outside of a sync block (for ports received during a sync
     /// block, pass them when calling `notify_sync_end`).
     pub(crate) fn push_port(&mut self, port: Port) {
         debug_assert!(!self.is_in_sync);
         self.state_changes.push_back(ComponentStateChange::CreatedPort(port))
+    }
     /// Notify the runtime of an error. Note that this will not perform any
     /// special action beyond printing the error. The component is responsible
     /// for waiting until it is appropriate to shut down (i.e. being outside
     /// of a sync region) and returning the `Exit` scheduling code.
     pub(crate) fn push_error(&mut self, error: EvalError) {
         println!("ERROR: Component ({}) encountered a critical error:\n{}", self.id.index, error);
+    }
     #[inline]
     pub(crate) fn get_ports(&self) -> &[Port] {
         return self.ports.as_slice();
+    }
     pub(crate) fn get_port_by_id(&self, id: PortIdLocal) -> Option<&Port> {
         return self.ports.iter().find(|v| v.self_id == id);
+    }
     pub(crate) fn get_port_by_channel_id(&self, id: ChannelId) -> Option<&Port> {
         return self.ports.iter().find(|v| v.channel_id == id);
+    }
     fn get_port_mut_by_id(&mut self, id: PortIdLocal) -> Option<&mut Port> {
         return self.ports.iter_mut().find(|v| v.self_id == id);
+    }
     /// Notify that component will enter a sync block. Note that after calling
     /// this function you must allow the scheduler to pick up the changes in the
     /// context by exiting your code-executing loop, and to continue executing
     /// code the next time the scheduler picks up the component.
     pub(crate) fn notify_sync_start(&mut self) {
         debug_assert!(!self.is_in_sync);
         self.is_in_sync = true;
         self.changed_in_sync = true;
+    }
     #[inline]
     pub(crate) fn is_in_sync(&self) -> bool {
         return self.is_in_sync;
+    }
     /// Submit a message for the scheduler to send to the appropriate receiver.
     /// May only be called inside of a sync block.
     pub(crate) fn submit_message(&mut self, contents: Message) -> Result<(), ()> {
         debug_assert!(self.is_in_sync);
         if let Some(port_id) = contents.source_port() {
             let port_info = self.get_port_by_id(port_id);
             let is_valid = match port_info {
                 Some(port_info) => {
                     port_info.state == PortState::Open
                 },
                 None => false,
             };
             if !is_valid {
                 // We don't own the port
                 return Err(());
+            }
+        }
         self.outbox.push_back(contents);
         return Ok(());
+    }
     /// Notify that component just finished a sync block. Like
     /// `notify_sync_start`: drop out of the `Component::Run` function.
     pub(crate) fn notify_sync_end(&mut self, changed_ports: &[ComponentPortChange]) {
         debug_assert!(self.is_in_sync);
         self.is_in_sync = false;
         self.changed_in_sync = true;
         self.state_changes.reserve(changed_ports.len());
         for changed_port in changed_ports {
             self.state_changes.push_back(ComponentStateChange::ChangedPort(changed_port.clone()));
+        }
+    }
     /// Retrieves messages matching a particular port and branch id. But only
     /// those messages that have been previously received with
     /// `read_next_message`.
     pub(crate) fn get_read_data_messages(&self, match_port_id: PortIdLocal) -> MessagesIter {
         return self.inbox.get_read_data_messages(match_port_id);
+    }
     pub(crate) fn get_next_message_ticket(&mut self) -> Option<MessageTicket> {
         if !self.is_in_sync { return None; }
         return self.inbox.get_next_message_ticket();
+    }
     #[inline]
     pub(crate) fn get_next_message_ticket_even_if_not_in_sync(&mut self) -> Option<MessageTicket> {
         return self.inbox.get_next_message_ticket();
+    }
     #[inline]
     pub(crate) fn read_message_using_ticket(&self, ticket: MessageTicket) -> &Message {
         return self.inbox.read_message_using_ticket(ticket);
+    }
     #[inline]
     pub(crate) fn take_message_using_ticket(&mut self, ticket: MessageTicket) -> Message {
         return self.inbox.take_message_using_ticket(ticket)
+    }
     /// Puts back a message back into the inbox. The reason being that the
     /// message is actually part of the next sync round. This will
     pub(crate) fn put_back_message(&mut self, message: Message) {
         self.inbox.put_back_message(message);
+    }
+}
 pub(crate) struct MessagesIter<'a> {
     messages: &'a [Message],
     next_index: usize,
     max_index: usize,
     match_port_id: PortIdLocal,
+}
 impl<'a> Iterator for MessagesIter<'a> {
     type Item = &'a DataMessage;
     fn next(&mut self) -> Option<Self::Item> {
         // Loop until match is found or at end of messages
         while self.next_index < self.max_index {
             let message = &self.messages[self.next_index];
             if let Message::Data(message) = &message {
                 if message.data_header.target_port == self.match_port_id {
                     // Found a match
                     self.next_index += 1;
                     return Some(message);
+                }
             } else {
                 // Unreachable because:
                 //  1. We only iterate over messages that were previously retrieved by `read_next_message`.
                 //  2. Inbox does not contain control/ping messages.
                 //  3. If `read_next_message` encounters anything else than a data message, it is removed from the inbox.
                 unreachable!();
+            }
             self.next_index += 1;
+        }
         // No more messages
         return None;
+    }
+}
 // -----------------------------------------------------------------------------
 // Private Inbox
 // -----------------------------------------------------------------------------
 /// A structure that contains inbox messages. Some messages are left inside and
 /// continuously re-read. Others are taken out, but may potentially be put back
 /// for later reading. Later reading in this case implies that they are put back
 /// for reading in the next sync round.
 /// TODO: Again, lazy concurrency, see git history for other implementation
 struct Inbox {
     messages: Vec<Message>,
     delayed: Vec<Message>,
     next_read_idx: u32,
     generation: u32,
+}
 #[derive(Clone, Copy)]
 pub(crate) struct MessageTicket {
     index: u32,
     generation: u32,
+}
 impl Inbox {
     fn new() -> Self {
         return Inbox {
             messages: Vec::new(),
             delayed: Vec::new(),
             next_read_idx: 0,
             generation: 0,
+        }
+    }
     fn insert_new(&mut self, message: Message) {
         assert!(self.messages.len() < u32::MAX as usize); // TODO: @Size
         self.messages.push(message);
+    }
     fn get_next_message_ticket(&mut self) -> Option<MessageTicket> {
         if self.next_read_idx as usize >= self.messages.len() { return None };
         let idx = self.next_read_idx;
         self.generation += 1;
         self.next_read_idx += 1;
         return Some(MessageTicket{ index: idx, generation: self.generation });
+    }
     fn read_message_using_ticket(&self, ticket: MessageTicket) -> &Message {
         debug_assert_eq!(self.generation, ticket.generation);
         return &self.messages[ticket.index as usize];
+    }
     fn take_message_using_ticket(&mut self, ticket: MessageTicket) -> Message {
         debug_assert_eq!(self.generation, ticket.generation);
         debug_assert!(ticket.index < self.next_read_idx);
         self.next_read_idx -= 1;
         return self.messages.remove(ticket.index as usize);
+    }
     fn put_back_message(&mut self, message: Message) {
         // We have space in front of the array because we've taken out a message
         // before.
         self.delayed.push(message);
+    }
     fn get_read_data_messages(&self, match_port_id: PortIdLocal) -> MessagesIter {
         return MessagesIter{
             messages: self.messages.as_slice(),
             next_index: 0,
             max_index: self.next_read_idx as usize,
             match_port_id
         };
+    }
     fn clear_read_messages(&mut self) {
         self.messages.drain(0..self.next_read_idx as usize);
         for (idx, v) in self.delayed.drain(..).enumerate() {
             self.messages.insert(idx, v);
+        }
         self.next_read_idx = 0;
+    }
     fn transfer_messages_for_port(&mut self, port: PortIdLocal, new_inbox: &mut Inbox) {
         debug_assert!(self.delayed.is_empty());
         let mut idx = 0;
         while idx < self.messages.len() {
             let msg = &self.messages[idx];
             if let Some(target) = msg.target_port() {
                 if target == port {
                     new_inbox.messages.push(self.messages.remove(idx));
                     continue;
+                }
+            }
             idx += 1;
+        }
+    }
+}
 // -----------------------------------------------------------------------------
 // Control messages
 // -----------------------------------------------------------------------------
 struct ControlEntry {
     id: u32,
     variant: ControlVariant,
+}
 enum ControlVariant {
     NewComponent(ControlNewComponent),
     ChangedPort(ControlChangedPort),
     ClosedChannel(ControlClosedChannel),
+}
 impl ControlVariant {
     fn as_new_component_mut(&mut self) -> &mut ControlNewComponent {
         match self {
             ControlVariant::NewComponent(v) => v,
             _ => unreachable!(),
+        }
+    }
+}
 /// Entry for a new component waiting for execution after all of its peers have
 /// confirmed the `ControlChangedPort` messages.
 struct ControlNewComponent {
     num_acks_pending: u32,          // if it hits 0, we schedule the component
     component_key: ConnectorKey,    // this is the component we schedule
+}
 struct ControlChangedPort {
     reroute_if_sent_to_this_port: PortIdLocal, // if sent to this port, then reroute
     source_connector: ConnectorId,             // connector we expect messages from
     target_connector: ConnectorId,             // connector we need to reroute to
     new_component_entry_id: u32,               // if Ack'd, we reduce the counter on this `ControlNewComponent` entry
+}
 struct ControlClosedChannel {
     source_port: PortIdLocal,
     target_port: PortIdLocal,
+}
 pub(crate) struct ControlMessageHandler {
     id_counter: u32,
     active: Vec<ControlEntry>,
+}
 impl ControlMessageHandler {
     pub fn new() -> Self {
         ControlMessageHandler {
             id_counter: 0,
             active: Vec::new(),
+        }
+    }
     /// Prepares a message indicating that a channel has closed, we keep a local
     /// entry to match against the (hopefully) returned `Ack` message.
     pub fn prepare_closing_channel(
         &mut self, self_port_id: PortIdLocal, peer_port_id: PortIdLocal,
         self_connector_id: ConnectorId
     ) -> ControlMessage {
         let id = self.take_id();
         self.active.push(ControlEntry{
             id,
             variant: ControlVariant::ClosedChannel(ControlClosedChannel{

src/runtime2/communication.rs

➞

Show inline comments

 use crate::protocol::eval::*;
 use super::runtime::*;
 use super::component::*;
 // -----------------------------------------------------------------------------
 // Generic types
 // -----------------------------------------------------------------------------
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub struct PortId(pub u32);
 impl PortId {
     /// This value is not significant, it is chosen to make debugging easier: a
     /// very large port number is more likely to shine a light on bugs.
     pub fn new_invalid() -> Self {
         return Self(u32::MAX);
+    }
+}
 pub struct CompPortIds {
     pub comp: CompId,
     pub port: PortId,
+}
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub enum PortKind {
     Putter,
     Getter,
+}
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum PortState {
     Open,
     BlockedDueToPeerChange,
     BlockedDueToFullBuffers,
     Closed,
+}
 impl PortState {
     pub fn is_blocked(&self) -> bool {
         match self {
             PortState::BlockedDueToPeerChange | PortState::BlockedDueToFullBuffers => true,
             PortState::Open | PortState::Closed => false,
+        }
+    }
+}
 pub struct Channel {
     pub putter_id: PortId,
     pub getter_id: PortId,
+}
 // -----------------------------------------------------------------------------
 // Data messages
 // -----------------------------------------------------------------------------
 #[derive(Debug)]
 pub struct DataMessage {
     pub data_header: MessageDataHeader,
     pub sync_header: MessageSyncHeader,
     pub content: ValueGroup,
+}
 #[derive(Debug)]
 pub enum PortAnnotationKind {
     Getter(PortAnnotationGetter),
     Putter(PortAnnotationPutter),
+}
 #[derive(Debug)]
 pub struct PortAnnotationGetter {
     pub self_comp_id: CompId,
     pub self_port_id: PortId,
     pub peer_comp_id: CompId,
     pub peer_port_id: PortId,
+}
 #[derive(Debug)]
 pub struct PortAnnotationPutter {
     pub self_comp_id: CompId,
     pub self_port_id: PortId,
+}
 #[derive(Debug)]
 pub struct MessageDataHeader {
-    pub expected_mapping: Vec<(PortId, Option<u32>)>,
+    pub expected_mapping: Vec<(PortAnnotationKind, Option<u32>)>,
     pub new_mapping: u32,
     pub source_port: PortId,
     pub target_port: PortId,
+}
 // -----------------------------------------------------------------------------
 // Sync messages
 // -----------------------------------------------------------------------------
 #[derive(Debug)]
 pub struct SyncMessage {
     pub sync_header: MessageSyncHeader,
     pub content: SyncMessageContent,
+}
 #[derive(Debug)]
 pub enum SyncLocalSolutionEntry {
     Putter(SyncSolutionPutterPort),
     Getter(SyncSolutionGetterPort),
+}
 pub type SyncLocalSolution = Vec<SyncLocalSolutionEntry>;
 /// Getter port in a solution. Upon receiving a message it is certain about who
 /// its peer is.
 #[derive(Debug)]
 pub struct SyncSolutionGetterPort {
     pub self_comp_id: CompId,
     pub self_port_id: PortId,
     pub peer_comp_id: CompId,
     pub peer_port_id: PortId,
     pub mapping: u32,
+}
 /// Putter port in a solution. A putter may not be certain about who its peer
 /// component/port is.
 #[derive(Debug)]
 pub struct SyncSolutionPutterPort {
     pub self_comp_id: CompId,
     pub self_port_id: PortId,
     pub mapping: u32,
+}
 #[derive(Debug)]
 pub struct SyncSolutionChannel {
     pub putter: Option<SyncSolutionPutterPort>,
     pub getter: Option<SyncSolutionGetterPort>,
+}
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub enum SyncRoundDecision {
     None,
     Solution,
     Failure,
+}
 #[derive(Debug)]
 pub struct SyncPartialSolution {
     pub channel_mapping: Vec<SyncSolutionChannel>,
     pub decision: SyncRoundDecision,
+}
 impl Default for SyncPartialSolution {
     fn default() -> Self {
         return Self{
             channel_mapping: Vec::new(),
             decision: SyncRoundDecision::None,
+        }
+    }
+}
 #[derive(Debug)]
 pub enum SyncMessageContent {
     NotificationOfLeader,
     LocalSolution(CompId, SyncLocalSolution), // local solution of the specified component
     PartialSolution(SyncPartialSolution), // partial solution of multiple components
     GlobalSolution,
     GlobalFailure,
+}
 // -----------------------------------------------------------------------------
 // Control messages
 // -----------------------------------------------------------------------------
 #[derive(Debug)]
 pub struct ControlMessage {
     pub(crate) id: ControlId,
     pub sender_comp_id: CompId,
     pub target_port_id: Option<PortId>,
     pub content: ControlMessageContent,
+}
 #[derive(Copy, Clone, Debug)]
 pub enum ControlMessageContent {
     Ack,
     BlockPort(PortId),
     UnblockPort(PortId),
     ClosePort(PortId),
     PortPeerChangedBlock(PortId),
     PortPeerChangedUnblock(PortId, CompId),
+}
 // -----------------------------------------------------------------------------
 // Messages (generic)
 // -----------------------------------------------------------------------------
 #[derive(Debug)]
 pub struct MessageSyncHeader {
     pub sync_round: u32,
     pub sending_id: CompId,
     pub highest_id: CompId,
+}
 #[derive(Debug)]
 pub enum Message {
     Data(DataMessage),
     Sync(SyncMessage),
     Control(ControlMessage),
+}
 impl Message {
     pub(crate) fn target_port(&self) -> Option<PortId> {
         match self {
             Message::Data(v) =>
                 return Some(v.data_header.target_port),
             Message::Control(v) =>
                 return v.target_port_id,
             Message::Sync(_) =>
                 return None,
+        }
+    }
     pub(crate) fn modify_target_port(&mut self, port_id: PortId) {
         match self {
             Message::Data(v) =>
                 v.data_header.target_port = port_id,
             Message::Control(v) =>
                 v.target_port_id = Some(port_id),
             Message::Sync(_) => unreachable!(), // should never be called for this message type
+        }
+    }
+}

src/runtime2/component/component_context.rs

➞

Show inline comments

 use crate::runtime2::scheduler::*;
 use crate::runtime2::runtime::*;
 use crate::runtime2::communication::*;
 #[derive(Debug)]
 pub struct Port {
     pub self_id: PortId,
     pub peer_comp_id: CompId, // eventually consistent
     pub peer_port_id: PortId, // eventually consistent
     pub kind: PortKind,
     pub state: PortState,
     #[cfg(debug_assertions)] pub(crate) associated_with_peer: bool,
 }
 pub struct Peer {
     pub id: CompId,
     pub num_associated_ports: u32,
     pub(crate) handle: CompHandle,
 }
 /// Port and peer management structure. Will keep a local reference counter to
 /// the ports associate with peers, additionally manages the atomic reference
 /// counter associated with the peers' component handles.
 pub struct CompCtx {
     pub id: CompId,
     ports: Vec<Port>,
     peers: Vec<Peer>,
     port_id_counter: u32,
 }
 #[derive(Copy, Clone, PartialEq, Eq)]
 pub struct LocalPortHandle(PortId);
 #[derive(Copy, Clone)]
 pub struct LocalPeerHandle(CompId);
 impl CompCtx {
     /// Creates a new component context based on a reserved entry in the
     /// component store. This reservation is used such that we already know our
     /// assigned ID.
     pub(crate) fn new(reservation: &CompReserved) -> Self {
         return Self{
             id: reservation.id(),
             ports: Vec::new(),
             peers: Vec::new(),
             port_id_counter: 0,
         }
     }
     /// Creates a new channel that is fully owned by the component associated
     /// with this context.
     pub(crate) fn create_channel(&mut self) -> Channel {
         let putter_id = PortId(self.take_port_id());
         let getter_id = PortId(self.take_port_id());
         self.ports.push(Port{
             self_id: putter_id,
             peer_port_id: getter_id,
             kind: PortKind::Putter,
             state: PortState::Open,
             peer_comp_id: self.id,
             associated_with_peer: false,
+            #[cfg(debug_assertions)] associated_with_peer: false,
         });
         self.ports.push(Port{
             self_id: getter_id,
             peer_port_id: putter_id,
             kind: PortKind::Getter,
             state: PortState::Open,
             peer_comp_id: self.id,
             associated_with_peer: false,
+            #[cfg(debug_assertions)] associated_with_peer: false,
         });
         return Channel{ putter_id, getter_id };
     }
     /// Adds a new port. Make sure to call `add_peer` afterwards.
     pub(crate) fn add_port(&mut self, peer_comp_id: CompId, peer_port_id: PortId, kind: PortKind, state: PortState) -> LocalPortHandle {
         let self_id = PortId(self.take_port_id());
         self.ports.push(Port{
             self_id, peer_comp_id, peer_port_id, kind, state,
             #[cfg(debug_assertions)] associated_with_peer: false,
         });
         return LocalPortHandle(self_id);
     }
     /// Removes a port. Make sure you called `remove_peer` first.
     pub(crate) fn remove_port(&mut self, port_handle: LocalPortHandle) -> Port {
         let port_index = self.must_get_port_index(port_handle);
         let port = self.ports.remove(port_index);
-        debug_assert!(!port.associated_with_peer);
+        dbg_code!(assert!(!port.associated_with_peer));
         return port;
     }
     /// Adds a new peer. This must be called for every port, no matter the
     /// component the channel is connected to. If a `CompHandle` is supplied,
     /// then it will be used to add the peer. Otherwise it will be retrieved
     /// from the runtime using its ID.
     pub(crate) fn add_peer(&mut self, port_handle: LocalPortHandle, sched_ctx: &SchedulerCtx, peer_comp_id: CompId, handle: Option<&CompHandle>) {
         let self_id = self.id;
         let port = self.get_port_mut(port_handle);
         debug_assert_eq!(port.peer_comp_id, peer_comp_id);
-        debug_assert!(!port.associated_with_peer);
+        dbg_code!(assert!(!port.associated_with_peer));
         if !Self::requires_peer_reference(port, self_id, false) {
             return;
         }
         dbg_code!(port.associated_with_peer = true);
         match self.get_peer_index_by_id(peer_comp_id) {
             Some(peer_index) => {
                 let peer = &mut self.peers[peer_index];
                 peer.num_associated_ports += 1;
             },
             None => {
                 let handle = match handle {
                     Some(handle) => handle.clone(),
                     None => sched_ctx.runtime.get_component_public(peer_comp_id)
                 };
                 self.peers.push(Peer{
                     id: peer_comp_id,
                     num_associated_ports: 1,
                     handle,
                 });
             }
         }
     }
     /// Removes a peer associated with a port.
     pub(crate) fn remove_peer(&mut self, sched_ctx: &SchedulerCtx, port_handle: LocalPortHandle, peer_id: CompId, also_remove_if_closed: bool) {
         let self_id = self.id;
         let port = self.get_port_mut(port_handle);
         debug_assert_eq!(port.peer_comp_id, peer_id);
         if !Self::requires_peer_reference(port, self_id, also_remove_if_closed) {
             return;
         }
-        debug_assert!(port.associated_with_peer);
+        dbg_code!(assert!(port.associated_with_peer));
         dbg_code!(port.associated_with_peer = false);
         let peer_index = self.get_peer_index_by_id(peer_id).unwrap();
         let peer = &mut self.peers[peer_index];
         peer.num_associated_ports -= 1;
         if peer.num_associated_ports == 0 {
             let mut peer = self.peers.remove(peer_index);
             if let Some(key) = peer.handle.decrement_users() {
                 debug_assert_ne!(key.downgrade(), self.id); // should be upheld by the code that shuts down a component
                 sched_ctx.runtime.destroy_component(key);
             }
         }
     }
     pub(crate) fn set_port_state(&mut self, port_handle: LocalPortHandle, new_state: PortState) {
         let port_info = self.get_port_mut(port_handle);
         debug_assert_ne!(port_info.state, PortState::Closed); // because then we do not expect to change the state
         port_info.state = new_state;
     }
     pub(crate) fn get_port_handle(&self, port_id: PortId) -> LocalPortHandle {
         return LocalPortHandle(port_id);
     }
     // should perhaps be revised, used in main inbox
     pub(crate) fn get_port_index(&self, port_handle: LocalPortHandle) -> usize {
         return self.must_get_port_index(port_handle);
     }
     pub(crate) fn get_peer_handle(&self, peer_id: CompId) -> LocalPeerHandle {
         return LocalPeerHandle(peer_id);
     }
     pub(crate) fn get_port(&self, port_handle: LocalPortHandle) -> &Port {
         let index = self.must_get_port_index(port_handle);
         return &self.ports[index];
     }
     pub(crate) fn get_port_mut(&mut self, port_handle: LocalPortHandle) -> &mut Port {
         let index = self.must_get_port_index(port_handle);
         return &mut self.ports[index];
     }
     pub(crate) fn get_port_by_index_mut(&mut self, index: usize) -> &mut Port {
         return &mut self.ports[index];
     }
     pub(crate) fn get_peer(&self, peer_handle: LocalPeerHandle) -> &Peer {
         let index = self.must_get_peer_index(peer_handle);
         return &self.peers[index];
     }
     pub(crate) fn get_peer_mut(&mut self, peer_handle: LocalPeerHandle) -> &mut Peer {
         let index = self.must_get_peer_index(peer_handle);
         return &mut self.peers[index];
     }
     #[inline]
     pub(crate) fn iter_ports(&self) -> impl Iterator<Item=&Port> {
         return self.ports.iter();
     }
     #[inline]
     pub(crate) fn iter_ports_mut(&mut self) -> impl Iterator<Item=&mut Port> {
         return self.ports.iter_mut();
     }
     #[inline]
     pub(crate) fn iter_peers(&self) -> impl Iterator<Item=&Peer> {
         return self.peers.iter();
     }
     #[inline]
     pub(crate) fn num_ports(&self) -> usize {
         return self.ports.len();
     }
     // -------------------------------------------------------------------------
     // Local utilities
     // -------------------------------------------------------------------------
     #[inline]
     fn requires_peer_reference(port: &Port, self_id: CompId, required_if_closed: bool) -> bool {
         return (port.state != PortState::Closed || required_if_closed) && port.peer_comp_id != self_id;
     }
     fn must_get_port_index(&self, handle: LocalPortHandle) -> usize {
         for (index, port) in self.ports.iter().enumerate() {
             if port.self_id == handle.0 {
                 return index;
             }
         }
         unreachable!()
     }
     fn must_get_peer_index(&self, handle: LocalPeerHandle) -> usize {
         for (index, peer) in self.peers.iter().enumerate() {
             if peer.id == handle.0 {
                 return index;
             }
         }
         unreachable!()
     }
     fn get_peer_index_by_id(&self, comp_id: CompId) -> Option<usize> {
         for (index, peer) in self.peers.iter().enumerate() {
             if peer.id == comp_id {
                 return Some(index);
             }
         }
         return None;
     }
     fn take_port_id(&mut self) -> u32 {
         let port_id = self.port_id_counter;
         self.port_id_counter = self.port_id_counter.wrapping_add(1);
         return port_id;
     }
 }
@@ \ No newline at end of file @@

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