Changeset f80e0218 for src/SynTree/CompoundStmt.cc

Timestamp:

Jun 30, 2016, 4:32:56 PM (10 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, ctor, deferred_resn, demangler, enum, forall-pointer-decay, gc_noraii, jacob/cs343-translation, jenkins-sandbox, master, memory, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, pthread-emulation, qualifiedEnum, resolv-new, with_gc

Children:

ea29e73

Parents:

1b5c81ed (diff), 84d4d6f (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' into gc_noraii

Conflicts:

Jenkinsfile
src/SymTab/Validate.cc

File:

• src/SynTree/CompoundStmt.cc (modified) (4 diffs)

src/SynTree/CompoundStmt.cc

@@ -5 +5 @@
 // file "LICENCE" distributed with Cforall.
 //
-// XXX.cc -- 
+// XXX.cc --
 //
 // Author           : Richard C. Bilson
 // Created On       : Mon May 18 07:44:20 2015
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Tue Jun 23 11:37:49 2015
+// Last Modified By : Rob Schluntz
+// Last Modified On : Mon May 02 15:19:17 2016
 // Update Count     : 3
 //
@@ -18 +18 @@
 #include <algorithm>
 #include <functional>
+#include "Expression.h"
+#include "Declaration.h"
 
 using std::string;
 using std::endl;
+
+class VarExprReplacer : public Visitor {
+public:
+  typedef std::map< DeclarationWithType *, DeclarationWithType * > DeclMap;
+private:
+  const DeclMap & declMap;
+public:
+  VarExprReplacer( const DeclMap & declMap ) : declMap( declMap ) {}
+
+  // replace variable with new node from decl map
+  virtual void visit( VariableExpr * varExpr ) {
+    if ( declMap.count( varExpr->get_var() ) ) {
+      varExpr->set_var( declMap.at( varExpr->get_var() ) );
+    }
+  }
+};
+
 
 CompoundStmt::CompoundStmt( std::list<Label> labels ) : Statement( labels ) {
@@ -27 +46 @@
 CompoundStmt::CompoundStmt( const CompoundStmt &other ) : Statement( other ) {
         cloneAll( other.kids, kids );
+
+  // when cloning a compound statement, we may end up cloning declarations which
+  // are referred to by VariableExprs throughout the block. Cloning a VariableExpr
+  // does a shallow copy, so the VariableExpr will end up pointing to the original
+  // declaration. If the original declaration is deleted, e.g. because the original
+  // CompoundStmt is deleted, then we have a dangling pointer. To avoid this case,
+  // find all DeclarationWithType nodes (since a VariableExpr must point to a
+  // DeclarationWithType) in the original CompoundStmt and map them to the cloned
+  // node in the new CompoundStmt ('this'), then replace the Declarations referred to
+  // by each VariableExpr according to the constructed map. Note that only the declarations
+  // in the current level are collected into the map, because child CompoundStmts will
+  // recursively execute this routine. There may be more efficient ways of doing
+  // this.
+  VarExprReplacer::DeclMap declMap;
+  std::list< Statement * >::const_iterator origit = other.kids.begin();
+  for ( Statement * s : kids ) {
+    assert( origit != other.kids.end() );
+    if ( DeclStmt * declStmt = dynamic_cast< DeclStmt * >( s ) ) {
+      DeclStmt * origDeclStmt = dynamic_cast< DeclStmt * >( *origit );
+      assert( origDeclStmt );
+      if ( DeclarationWithType * dwt = dynamic_cast< DeclarationWithType * > ( declStmt->get_decl() ) ) {
+        DeclarationWithType * origdwt = dynamic_cast< DeclarationWithType * > ( origDeclStmt->get_decl() );
+        assert( origdwt );
+        declMap[ origdwt ] = dwt;
+      }
+    }
+  }
+  if ( ! declMap.empty() ) {
+    VarExprReplacer replacer( declMap );
+    accept( replacer );
+  }
 }
 
@@ -34 +84 @@
 
 void CompoundStmt::print( std::ostream &os, int indent ) const {
-        os << string( indent, ' ' ) << "CompoundStmt" << endl ;
+        os << "CompoundStmt" << endl ;
         printAll( kids, os, indent + 2 );
 }