Changeset 4789f44 for src/GenPoly/Box.cc

Timestamp:

Feb 5, 2016, 12:28:21 PM (9 years ago)

Author:

Rob Schluntz <rschlunt@…>

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, string, with_gc

Children:

408d460, bd85400

Parents:

b4cd03b7 (diff), 2a4b088 (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 fix-argument-passing-type-warnings

File:

• src/GenPoly/Box.cc (modified) (4 diffs)

src/GenPoly/Box.cc

@@ -123 +123 @@
                 };
 
-                /// Replaces member expressions for polymorphic types with calculated add-field-offset-and-dereference
+                /// Replaces member expressions for polymorphic types with calculated add-field-offset-and-dereference;
+                /// also fixes offsetof expressions.
                 class MemberExprFixer : public PolyMutator {
                   public:
@@ -136 +137 @@
                         virtual Type *mutate( FunctionType *funcType );
                         virtual Expression *mutate( MemberExpr *memberExpr );
+                        virtual Expression *mutate( OffsetofExpr *offsetofExpr );
                 };
 
@@ -1283 +1285 @@
                 }
 
+                /// Finds the member in the base list that matches the given declaration; returns its index, or -1 if not present
+                long findMember( DeclarationWithType *memberDecl, std::list< Declaration* > &baseDecls ) {
+                        long i = 0;
+                        for(std::list< Declaration* >::const_iterator decl = baseDecls.begin(); decl != baseDecls.end(); ++decl, ++i ) {
+                                if ( memberDecl->get_name() != (*decl)->get_name() ) continue;
+
+                                if ( DeclarationWithType *declWithType = dynamic_cast< DeclarationWithType* >( *decl ) ) {
+                                        if ( memberDecl->get_mangleName() == declWithType->get_mangleName() ) return i;
+                                        else continue;
+                                } else return i;
+                        }
+                        return -1;
+                }
+
+                /// Returns an index expression into the offset array for a type
+                Expression *makeOffsetIndex( Type *objectType, long i ) {
+                        std::stringstream offset_namer;
+                        offset_namer << i;
+                        ConstantExpr *fieldIndex = new ConstantExpr( Constant( new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt ), offset_namer.str() ) );
+                        UntypedExpr *fieldOffset = new UntypedExpr( new NameExpr( "?[?]" ) );
+                        fieldOffset->get_args().push_back( new NameExpr( offsetofName( objectType ) ) );
+                        fieldOffset->get_args().push_back( fieldIndex );
+                        return fieldOffset;
+                }
+
+                /// Returns an expression dereferenced n times
+                Expression *makeDerefdVar( Expression *derefdVar, long n ) {
+                        for ( int i = 1; i < n; ++i ) {
+                                UntypedExpr *derefExpr = new UntypedExpr( new NameExpr( "*?" ) );
+                                derefExpr->get_args().push_back( derefdVar );
+                                derefdVar = derefExpr;
+                        }
+                        return derefdVar;
+                }
+                
                 Expression *MemberExprFixer::mutate( MemberExpr *memberExpr ) {
                         // mutate, exiting early if no longer MemberExpr
@@ -1301 +1338 @@
                         if ( ! objectType ) return memberExpr;
 
-                        // get base aggregate for type so members can be looked up
-                        AggregateDecl *memberBase = 0;
                         if ( StructInstType *structType = dynamic_cast< StructInstType* >( objectType ) ) {
-                                memberBase = structType->get_baseStruct();
+                                // look up offset index
+                                long i = findMember( memberExpr->get_member(), structType->get_baseStruct()->get_members() );
+                                if ( i == -1 ) return memberExpr;
+
+                                // replace member expression with pointer to base plus offset
+                                UntypedExpr *fieldLoc = new UntypedExpr( new NameExpr( "?+?" ) );
+                                fieldLoc->get_args().push_back( makeDerefdVar( varExpr->clone(), varDepth ) );
+                                fieldLoc->get_args().push_back( makeOffsetIndex( objectType, i ) );
+
+                                delete memberExpr;
+                                return fieldLoc;
                         } else if ( UnionInstType *unionType = dynamic_cast< UnionInstType* >( objectType ) ) {
-                                memberBase = unionType->get_baseUnion();
+                                // union members are all at offset zero, so build appropriately-dereferenced variable
+                                Expression *derefdVar = makeDerefdVar( varExpr->clone(), varDepth );
+                                delete memberExpr;
+                                return derefdVar;
                         } else return memberExpr;
-
-                        // look up numeric index of member in base aggregate
-                        DeclarationWithType *memberDecl = memberExpr->get_member();
-                        std::list< Declaration* > &baseDecls = memberBase->get_members();
-                        std::list< Declaration* >::const_iterator decl = baseDecls.begin();
-                        unsigned long i = 0;
-                        for( ; decl != baseDecls.end(); ++decl, ++i ) {
-                                if ( memberDecl->get_name() != (*decl)->get_name() ) continue;
-
-                                if ( DeclarationWithType *declWithType = dynamic_cast< DeclarationWithType* >( *decl ) ) {
-                                        if ( memberDecl->get_mangleName() == declWithType->get_mangleName() ) break;
-                                        else continue;
-                                } else break;
-                        }
-                        if ( decl == baseDecls.end() ) return memberExpr;
-
-                        // replace member expression with pointer to base plus offset
-                        // get offset for field
-                        std::stringstream offset_namer;
-                        offset_namer << i;
-                        ConstantExpr *fieldIndex = new ConstantExpr( Constant( new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt ), offset_namer.str() ) );
-                        UntypedExpr *fieldOffset = new UntypedExpr( new NameExpr( "?[?]" ) );
-                        fieldOffset->get_args().push_back( new NameExpr( offsetofName( objectType ) ) );
-                        fieldOffset->get_args().push_back( fieldIndex );
-                        // build appropriately-dereferenced variable
-                        Expression *derefdVar = varExpr->clone();
-                        for ( int i = 1; i < varDepth; ++i ) {
-                                UntypedExpr *derefExpr = new UntypedExpr( new NameExpr( "*?" ) );
-                                derefExpr->get_args().push_back( derefdVar );
-                                derefdVar = derefExpr;
-                        }
-                        // add offset to deref'd variable
-                        UntypedExpr *fieldLoc = new UntypedExpr( new NameExpr( "?+?" ) );
-                        fieldLoc->get_args().push_back( derefdVar );
-                        fieldLoc->get_args().push_back( fieldOffset );
-
-                        delete memberExpr;
-                        return fieldLoc;
+                }
+
+                Expression *MemberExprFixer::mutate( OffsetofExpr *offsetofExpr ) {
+                        // mutate, exiting early if no longer OffsetofExpr
+                        Expression *expr = Mutator::mutate( offsetofExpr );
+                        offsetofExpr = dynamic_cast< OffsetofExpr* >( expr );
+                        if ( ! offsetofExpr ) return expr;
+
+                        // only mutate expressions for polymorphic structs/unions
+                        Type *ty = isPolyType( offsetofExpr->get_type(), scopeTyVars );
+                        if ( ! ty ) return offsetofExpr;
+
+                        if ( StructInstType *structType = dynamic_cast< StructInstType* >( ty ) ) {
+                                // replace offsetof expression by index into offset array
+                                long i = findMember( offsetofExpr->get_member(), structType->get_baseStruct()->get_members() );
+                                if ( i == -1 ) return offsetofExpr;
+
+                                Expression *offsetInd = makeOffsetIndex( ty, i );
+                                delete offsetofExpr;
+                                return offsetInd;
+                        } else if ( UnionInstType *unionType = dynamic_cast< UnionInstType* >( ty ) ) {
+                                // all union members are at offset zero
+                                delete offsetofExpr;
+                                return new ConstantExpr( Constant( new BasicType( Type::Qualifiers(), BasicType::LongUnsignedInt ), std::string("0") ) );
+                        } else return offsetofExpr;
                 }