CSY/reowolf Changeset - e16722f0d0ac · Centrum Wiskunde & Informatica (CWI)

Changeset - e16722f0d0ac

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Hans-Dieter Hiep - 5 years ago 2020-02-10 15:48:57
hdh@cwi.nl

Lift parser restriction on assignable expressions

3 files changed with 5 insertions and 8 deletions:

src/protocol/parser.rs

testdata/parser/negative/20.txt

testdata/parser/positive/20.pdl

rename

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src/protocol/parser.rs

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@@ @@ -1386,440 +1386,440 @@ impl Visitor for ResolveLabels { @@
         if let Some(label) = h[stmt].label {
             let target = self.get_target(h, label)?;
             let target = &h[h[target].body];
             if !target.is_while() {
                 return Err(ParseError::new(
                     h[stmt].position,
                     "Illegal continue: target not a while statement",
                 ));
+            }
             the_while = target.as_while();
         // TODO: check if continue is nested under while
         } else {
             if self.while_enclosure.is_none() {
                 return Err(ParseError::new(
                     h[stmt].position,
                     "Illegal continue: no surrounding while statement",
                 ));
+            }
             the_while = &h[self.while_enclosure.unwrap()];
             // continue is always nested under while, by recursive vistor
+        }
         if the_while.in_sync != self.sync_enclosure {
             return Err(ParseError::new(
                 h[stmt].position,
                 "Illegal continue: synchronous statement escape",
             ));
+        }
         h[stmt].target = Some(the_while.this);
         Ok(())
+    }
     fn visit_synchronous_statement(
         &mut self,
         h: &mut Heap,
         stmt: SynchronousStatementId,
     ) -> VisitorResult {
         assert!(self.sync_enclosure.is_none());
         self.sync_enclosure = Some(stmt);
         recursive_synchronous_statement(self, h, stmt)?;
         self.sync_enclosure = None;
         Ok(())
+    }
     fn visit_goto_statement(&mut self, h: &mut Heap, stmt: GotoStatementId) -> VisitorResult {
         let target = self.get_target(h, h[stmt].label)?;
         if h[target].in_sync != self.sync_enclosure {
             return Err(ParseError::new(
                 h[stmt].position,
                 "Illegal goto: synchronous statement escape",
             ));
+        }
         h[stmt].target = Some(target);
         Ok(())
+    }
     fn visit_expression(&mut self, h: &mut Heap, expr: ExpressionId) -> VisitorResult {
         Ok(())
+    }
+}
 struct AssignableExpressions {
     assignable: bool,
+}
 impl AssignableExpressions {
     fn new() -> Self {
         AssignableExpressions { assignable: false }
+    }
     fn error(&self, position: InputPosition) -> VisitorResult {
         Err(ParseError::new(position, "Unassignable expression"))
+    }
+}
 impl Visitor for AssignableExpressions {
     fn visit_assignment_expression(
         &mut self,
         h: &mut Heap,
         expr: AssignmentExpressionId,
     ) -> VisitorResult {
         if self.assignable {
             self.error(h[expr].position)
         } else {
             self.assignable = true;
             self.visit_expression(h, h[expr].left)?;
             self.assignable = false;
             self.visit_expression(h, h[expr].right)
+        }
+    }
     fn visit_conditional_expression(
         &mut self,
         h: &mut Heap,
         expr: ConditionalExpressionId,
     ) -> VisitorResult {
         if self.assignable {
             self.error(h[expr].position)
         } else {
             recursive_conditional_expression(self, h, expr)
+        }
+    }
     fn visit_binary_expression(&mut self, h: &mut Heap, expr: BinaryExpressionId) -> VisitorResult {
         if self.assignable {
             self.error(h[expr].position)
         } else {
             recursive_binary_expression(self, h, expr)
+        }
+    }
     fn visit_unary_expression(&mut self, h: &mut Heap, expr: UnaryExpressionId) -> VisitorResult {
         if self.assignable {
             self.error(h[expr].position)
         } else {
             match h[expr].operation {
                 UnaryOperation::PostDecrement
                 | UnaryOperation::PreDecrement
                 | UnaryOperation::PostIncrement
                 | UnaryOperation::PreIncrement => {
                     self.assignable = true;
                     recursive_unary_expression(self, h, expr)?;
                     self.assignable = false;
                     Ok(())
+                }
                 _ => recursive_unary_expression(self, h, expr),
+            }
+        }
+    }
     fn visit_indexing_expression(
         &mut self,
         h: &mut Heap,
         expr: IndexingExpressionId,
     ) -> VisitorResult {
         let old = self.assignable;
         self.assignable = false;
         recursive_indexing_expression(self, h, expr)?;
         self.assignable = old;
         Ok(())
+    }
     fn visit_slicing_expression(
         &mut self,
         h: &mut Heap,
         expr: SlicingExpressionId,
     ) -> VisitorResult {
         let old = self.assignable;
         self.assignable = false;
         recursive_slicing_expression(self, h, expr)?;
         self.assignable = old;
         Ok(())
+    }
     fn visit_select_expression(&mut self, h: &mut Heap, expr: SelectExpressionId) -> VisitorResult {
         if h[expr].field.is_length() && self.assignable {
             return self.error(h[expr].position);
+        }
         let old = self.assignable;
         self.assignable = false;
         recursive_select_expression(self, h, expr)?;
         self.assignable = old;
         Ok(())
+    }
     fn visit_array_expression(&mut self, h: &mut Heap, expr: ArrayExpressionId) -> VisitorResult {
         if self.assignable {
             self.error(h[expr].position)
         } else {
             recursive_array_expression(self, h, expr)
+        }
+    }
     fn visit_call_expression(&mut self, h: &mut Heap, expr: CallExpressionId) -> VisitorResult {
         if self.assignable {
             self.error(h[expr].position)
         } else {
             recursive_call_expression(self, h, expr)
+        }
+    }
     fn visit_constant_expression(
         &mut self,
         h: &mut Heap,
         expr: ConstantExpressionId,
     ) -> VisitorResult {
         if self.assignable {
             self.error(h[expr].position)
         } else {
             Ok(())
+        }
+    }
     fn visit_variable_expression(
         &mut self,
         h: &mut Heap,
         expr: VariableExpressionId,
     ) -> VisitorResult {
         Ok(())
+    }
+}
 struct IndexableExpressions {
     indexable: bool,
+}
 impl IndexableExpressions {
     fn new() -> Self {
         IndexableExpressions { indexable: false }
+    }
     fn new() -> Self {  IndexableExpressions { indexable: false }  }
     fn error(&self, position: InputPosition) -> VisitorResult {
         Err(ParseError::new(position, "Unindexable expression"))
+    }
+}
 impl Visitor for IndexableExpressions {
     fn visit_assignment_expression(
         &mut self,
         h: &mut Heap,
         expr: AssignmentExpressionId,
     ) -> VisitorResult {
         if self.indexable {
             self.error(h[expr].position)
         } else {
             recursive_assignment_expression(self, h, expr)
+        }
+    }
     fn visit_conditional_expression(
         &mut self,
         h: &mut Heap,
         expr: ConditionalExpressionId,
     ) -> VisitorResult {
         let old = self.indexable;
         self.indexable = false;
         self.visit_expression(h, h[expr].test)?;
         self.indexable = old;
         self.visit_expression(h, h[expr].true_expression)?;
         self.visit_expression(h, h[expr].false_expression)
+    }
     fn visit_binary_expression(&mut self, h: &mut Heap, expr: BinaryExpressionId) -> VisitorResult {
         if self.indexable && h[expr].operation != BinaryOperator::Concatenate {
             self.error(h[expr].position)
         } else {
             recursive_binary_expression(self, h, expr)
+        }
+    }
     fn visit_unary_expression(&mut self, h: &mut Heap, expr: UnaryExpressionId) -> VisitorResult {
         if self.indexable {
             self.error(h[expr].position)
         } else {
             recursive_unary_expression(self, h, expr)
+        }
+    }
     fn visit_indexing_expression(
         &mut self,
         h: &mut Heap,
         expr: IndexingExpressionId,
     ) -> VisitorResult {
         let old = self.indexable;
-        self.indexable = false;
+        self.indexable = true;
         self.visit_expression(h, h[expr].subject)?;
         self.indexable = false;
         self.visit_expression(h, h[expr].index)?;
         self.indexable = old;
-        self.visit_expression(h, h[expr].index)
+        Ok(())
+    }
     fn visit_slicing_expression(
         &mut self,
         h: &mut Heap,
         expr: SlicingExpressionId,
     ) -> VisitorResult {
         let old = self.indexable;
         self.indexable = true;
         self.visit_expression(h, h[expr].subject)?;
         self.indexable = false;
         self.visit_expression(h, h[expr].from_index)?;
         self.visit_expression(h, h[expr].to_index)?;
         self.indexable = old;
         Ok(())
+    }
     fn visit_select_expression(&mut self, h: &mut Heap, expr: SelectExpressionId) -> VisitorResult {
         let old = self.indexable;
         self.indexable = false;
         recursive_select_expression(self, h, expr)?;
         self.indexable = old;
         Ok(())
+    }
     fn visit_array_expression(&mut self, h: &mut Heap, expr: ArrayExpressionId) -> VisitorResult {
         let old = self.indexable;
         self.indexable = false;
         recursive_array_expression(self, h, expr)?;
         self.indexable = old;
         Ok(())
+    }
     fn visit_call_expression(&mut self, h: &mut Heap, expr: CallExpressionId) -> VisitorResult {
         let old = self.indexable;
         self.indexable = false;
         recursive_call_expression(self, h, expr)?;
         self.indexable = old;
         Ok(())
+    }
     fn visit_constant_expression(
         &mut self,
         h: &mut Heap,
         expr: ConstantExpressionId,
     ) -> VisitorResult {
         if self.indexable {
             self.error(h[expr].position)
         } else {
             Ok(())
+        }
+    }
+}
 struct SelectableExpressions {
     selectable: bool,
+}
 impl SelectableExpressions {
     fn new() -> Self {
         SelectableExpressions { selectable: false }
+    }
     fn error(&self, position: InputPosition) -> VisitorResult {
         Err(ParseError::new(position, "Unselectable expression"))
+    }
+}
 impl Visitor for SelectableExpressions {
     fn visit_assignment_expression(
         &mut self,
         h: &mut Heap,
         expr: AssignmentExpressionId,
     ) -> VisitorResult {
         // left-hand side of assignment can be skipped
         let old = self.selectable;
         self.selectable = false;
         self.visit_expression(h, h[expr].right)?;
         self.selectable = old;
         Ok(())
+    }
     fn visit_conditional_expression(
         &mut self,
         h: &mut Heap,
         expr: ConditionalExpressionId,
     ) -> VisitorResult {
         let old = self.selectable;
         self.selectable = false;
         self.visit_expression(h, h[expr].test)?;
         self.selectable = old;
         self.visit_expression(h, h[expr].true_expression)?;
         self.visit_expression(h, h[expr].false_expression)
+    }
     fn visit_binary_expression(&mut self, h: &mut Heap, expr: BinaryExpressionId) -> VisitorResult {
         if self.selectable && h[expr].operation != BinaryOperator::Concatenate {
             self.error(h[expr].position)
         } else {
             recursive_binary_expression(self, h, expr)
+        }
+    }
     fn visit_unary_expression(&mut self, h: &mut Heap, expr: UnaryExpressionId) -> VisitorResult {
         if self.selectable {
             self.error(h[expr].position)
         } else {
             recursive_unary_expression(self, h, expr)
+        }
+    }
     fn visit_indexing_expression(
         &mut self,
         h: &mut Heap,
         expr: IndexingExpressionId,
     ) -> VisitorResult {
         let old = self.selectable;
         self.selectable = false;
         recursive_indexing_expression(self, h, expr)?;
         self.selectable = old;
         Ok(())
+    }
     fn visit_slicing_expression(
         &mut self,
         h: &mut Heap,
         expr: SlicingExpressionId,
     ) -> VisitorResult {
         let old = self.selectable;
         self.selectable = false;
         recursive_slicing_expression(self, h, expr)?;
         self.selectable = old;
         Ok(())
+    }
     fn visit_select_expression(&mut self, h: &mut Heap, expr: SelectExpressionId) -> VisitorResult {
         let old = self.selectable;
         self.selectable = false;
         recursive_select_expression(self, h, expr)?;
         self.selectable = old;
         Ok(())
+    }
     fn visit_array_expression(&mut self, h: &mut Heap, expr: ArrayExpressionId) -> VisitorResult {
         let old = self.selectable;
         self.selectable = false;
         recursive_array_expression(self, h, expr)?;
         self.selectable = old;
         Ok(())
+    }
     fn visit_call_expression(&mut self, h: &mut Heap, expr: CallExpressionId) -> VisitorResult {
         let old = self.selectable;
         self.selectable = false;
         recursive_call_expression(self, h, expr)?;
         self.selectable = old;
         Ok(())
+    }
     fn visit_constant_expression(
         &mut self,
         h: &mut Heap,
         expr: ConstantExpressionId,
     ) -> VisitorResult {
         if self.selectable {
             self.error(h[expr].position)
         } else {
             Ok(())
+        }
+    }
+}
 pub struct Parser<'a> {
     source: &'a mut InputSource,
+}
 impl<'a> Parser<'a> {
     pub fn new(source: &'a mut InputSource) -> Self {
         Parser { source }
+    }
     pub fn parse(&mut self, h: &mut Heap) -> Result<RootId, ParseError> {
         let mut lex = Lexer::new(self.source);
         let pd = lex.consume_protocol_description(h)?;
         NestedSynchronousStatements::new().visit_protocol_description(h, pd)?;
         ChannelStatementOccurrences::new().visit_protocol_description(h, pd)?;
         FunctionStatementReturns::new().visit_protocol_description(h, pd)?;
         ComponentStatementReturnNew::new().visit_protocol_description(h, pd)?;
         CheckBuiltinOccurrences::new().visit_protocol_description(h, pd)?;
         BuildSymbolDeclarations::new().visit_protocol_description(h, pd)?;
         LinkCallExpressions::new().visit_protocol_description(h, pd)?;
         BuildScope::new().visit_protocol_description(h, pd)?;
         ResolveVariables::new().visit_protocol_description(h, pd)?;
         LinkStatements::new().visit_protocol_description(h, pd)?;
         BuildLabels::new().visit_protocol_description(h, pd)?;
         ResolveLabels::new().visit_protocol_description(h, pd)?;
         AssignableExpressions::new().visit_protocol_description(h, pd)?;
         IndexableExpressions::new().visit_protocol_description(h, pd)?;
         SelectableExpressions::new().visit_protocol_description(h, pd)?;
         Ok(pd)
+    }
+}
 #[cfg(test)]
 mod tests {
     extern crate test_generator;
     use std::fs::File;

testdata/parser/negative/20.txt

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deleted file

testdata/parser/positive/20.pdl

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file renamed from testdata/parser/negative/20.pdl to testdata/parser/positive/20.pdl

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