Changeset 597db97

Timestamp:

Mar 21, 2017, 4:54:31 PM (7 years ago)

Author:

Rob Schluntz <rschlunt@…>

Branches:

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

Children:

349b2cb

Parents:

623ecf3

Message:

fix order of destruction of unique expressions

File:

• src/InitTweak/FixInit.cc (modified) (13 diffs)

src/InitTweak/FixInit.cc

@@ -52 +52 @@
         namespace {
                 typedef std::unordered_map< Expression *, TypeSubstitution * > EnvMap;
+                typedef std::unordered_map< int, int > UnqCount;
 
                 class InsertImplicitCalls final : public GenPoly::PolyMutator {
@@ -74 +75 @@
                         /// generate/resolve copy construction expressions for each, and generate/resolve destructors for both
                         /// arguments and return value temporaries
-                        static void resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap );
+                        static void resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap, UnqCount & unqCount );
 
                         typedef SymTab::Indexer Parent;
                         using Parent::visit;
 
-                        ResolveCopyCtors( const EnvMap & envMap ) : envMap( envMap ) {}
+                        ResolveCopyCtors( const EnvMap & envMap, UnqCount & unqCount ) : envMap( envMap ), unqCount( unqCount ) {}
 
                         virtual void visit( ImplicitCopyCtorExpr * impCpCtorExpr ) override;
@@ -94 +95 @@
                         TypeSubstitution * env;
                         const EnvMap & envMap;
+                        UnqCount & unqCount; // count the number of times each unique expr ID appears
                 };
 
@@ -202 +204 @@
                 class FixCopyCtors final : public GenPoly::PolyMutator {
                   public:
+                        FixCopyCtors( UnqCount & unqCount ) : unqCount( unqCount ){}
                         /// expand ImplicitCopyCtorExpr nodes into the temporary declarations, copy constructors, call expression,
                         /// and destructors
-                        static void fixCopyCtors( std::list< Declaration * > &translationUnit );
+                        static void fixCopyCtors( std::list< Declaration * > &translationUnit, UnqCount & unqCount );
 
                         typedef GenPoly::PolyMutator Parent;
@@ -211 +214 @@
                         virtual Expression * mutate( UniqueExpr * unqExpr ) override;
                         virtual Expression * mutate( StmtExpr * stmtExpr ) override;
+
+                        UnqCount & unqCount;
                 };
 
@@ -272 +277 @@
 
                 EnvMap envMap;
+                UnqCount unqCount;
 
                 InsertImplicitCalls::insert( translationUnit, envMap );
-                ResolveCopyCtors::resolveImplicitCalls( translationUnit, envMap );
+                ResolveCopyCtors::resolveImplicitCalls( translationUnit, envMap, unqCount );
                 InsertDtors::insert( translationUnit );
                 FixInit::fixInitializers( translationUnit );
 
                 // FixCopyCtors must happen after FixInit, so that destructors are placed correctly
-                FixCopyCtors::fixCopyCtors( translationUnit );
+                FixCopyCtors::fixCopyCtors( translationUnit, unqCount );
 
                 GenStructMemberCalls::generate( translationUnit );
@@ -298 +304 @@
                 }
 
-                void ResolveCopyCtors::resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap ) {
-                        ResolveCopyCtors resolver( envMap );
+                void ResolveCopyCtors::resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap, UnqCount & unqCount ) {
+                        ResolveCopyCtors resolver( envMap, unqCount );
                         acceptAll( translationUnit, resolver );
                 }
@@ -329 +335 @@
                 }
 
-                void FixCopyCtors::fixCopyCtors( std::list< Declaration * > & translationUnit ) {
-                        FixCopyCtors fixer;
+                void FixCopyCtors::fixCopyCtors( std::list< Declaration * > & translationUnit, UnqCount & unqCount ) {
+                        FixCopyCtors fixer( unqCount );
                         mutateAll( translationUnit, fixer );
                 }
@@ -520 +526 @@
                 void ResolveCopyCtors::visit( UniqueExpr * unqExpr ) {
                         static std::unordered_set< int > vars;
+                        unqCount[ unqExpr->get_id() ]++;  // count the number of unique expressions for each ID
                         if ( vars.count( unqExpr->get_id() ) ) {
                                 // xxx - hack to prevent double-handling of unique exprs, otherwise too many temporary variables and destructors are generated
@@ -636 +643 @@
 
                 Expression * FixCopyCtors::mutate( UniqueExpr * unqExpr ) {
+                        unqCount[ unqExpr->get_id() ]--;
+                        static std::unordered_map< int, std::list< Statement * > > dtors;
                         static std::unordered_map< int, UniqueExpr * > unqMap;
                         static std::unordered_set< int > addDeref;
@@ -645 +654 @@
                                 delete unqExpr->get_result();
                                 unqExpr->set_result( maybeClone( unqExpr->get_expr()->get_result() ) );
+                                if ( unqCount[ unqExpr->get_id() ] == 0 ) {  // insert destructor after the last use of the unique expression
+                                        stmtsToAdd.splice( stmtsToAddAfter.end(), dtors[ unqExpr->get_id() ] );
+                                }
                                 if ( addDeref.count( unqExpr->get_id() ) ) {
                                         // other UniqueExpr was dereferenced because it was an lvalue return, so this one should be too
@@ -651 +663 @@
                                 return unqExpr;
                         }
-                        unqExpr = safe_dynamic_cast< UniqueExpr * >( Parent::mutate( unqExpr ) ); // stmtexprs contained should not be separately fixed, so this must occur after the lookup
+                        FixCopyCtors fixer( unqCount );
+                        unqExpr->set_expr( unqExpr->get_expr()->acceptMutator( fixer ) ); // stmtexprs contained should not be separately fixed, so this must occur after the lookup
+                        stmtsToAdd.splice( stmtsToAdd.end(), fixer.stmtsToAdd );
                         unqMap[unqExpr->get_id()] = unqExpr;
                         if ( UntypedExpr * deref = dynamic_cast< UntypedExpr * >( unqExpr->get_expr() ) ) {
@@ -661 +675 @@
                                 getCallArg( deref, 0 ) = unqExpr;
                                 addDeref.insert( unqExpr->get_id() );
+                                if ( unqCount[ unqExpr->get_id() ] == 0 ) {  // insert destructor after the last use of the unique expression
+                                        stmtsToAdd.splice( stmtsToAddAfter.end(), dtors[ unqExpr->get_id() ] );
+                                } else { // remember dtors for last instance of unique expr
+                                        dtors[ unqExpr->get_id() ] = fixer.stmtsToAddAfter;
+                                }
                                 return deref;
                         }