Changeset 8a6cf7e for src/InitTweak/FixInit.cc

Timestamp:

Jul 26, 2017, 4:26:08 PM (6 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:

2afec66

Parents:

d335627

Message:

Fix various reference features.

• Eliminate multiple address-ofs resulting from &(T&) [address-of reference-cast].
• Keep rvalue cast if reference base type is incompatible with rvalue type.
• Keep pointer qualifiers when eliminating reference types.
• Add VariableExpr::functionPointer helper function to create variable expressions with function pointer type.
• Change ConstructorExpr? translation so that it temporarily generates a 'fake' assignment operator rather than use UntypedExpr?, so that the correct transformations occur in the Lvalue pass. This is a hack that can be fixed once PassVisitor? properly supports Indexer.

File:

• src/InitTweak/FixInit.cc (modified) (1 diff)

src/InitTweak/FixInit.cc

@@ -1182 +1182 @@
                         ctorExpr->set_callExpr( nullptr );
                         ctorExpr->set_env( nullptr );
+                        delete ctorExpr;
 
                         Expression *& firstArg = callExpr->get_args().front();
-                        UntypedExpr * assign = new UntypedExpr( new NameExpr( "?=?" ) );
-                        assign->get_args().push_back( new VariableExpr( tmp ) );
-                        assign->get_args().push_back( firstArg );
-                        assign->set_result( ctorExpr->get_result()->clone() );
-                        firstArg = assign;
-
-                        CommaExpr * commaExpr = new CommaExpr( callExpr, new VariableExpr( tmp ) );
+
+                        // xxx - hack in 'fake' assignment operator until resolver can easily be called in this pass. Once the resolver can be used in PassVisitor, this hack goes away.
+
+                        // generate the type of assignment operator using the type of tmp minus any reference types
+                        Type * type = tmp->get_type()->stripReferences();
+                        FunctionType * ftype = SymTab::genAssignType( type );
+
+                        // generate fake assignment decl and call it using &tmp and &firstArg
+                        // since tmp is guaranteed to be a reference and we want to assign pointers
+                        FunctionDecl * assignDecl = new FunctionDecl( "?=?", Type::StorageClasses(), LinkageSpec::Intrinsic, ftype, nullptr );
+                        ApplicationExpr * assign = new ApplicationExpr( VariableExpr::functionPointer( assignDecl ) );
+                        assign->get_args().push_back( new AddressExpr( new VariableExpr( tmp ) ) );
+                        Expression * addrArg = new AddressExpr( firstArg );
+                        // if firstArg has type T&&, then &firstArg has type T*&.
+                        // Cast away the reference to a value type so that the argument
+                        // matches the assignment's parameter types
+                        if ( dynamic_cast<ReferenceType *>( addrArg->get_result() ) ) {
+                                addrArg = new CastExpr( addrArg, addrArg->get_result()->stripReferences()->clone() );
+                        }
+                        assign->get_args().push_back( addrArg );
+                        firstArg = new VariableExpr( tmp );
+
+                        // for constructor expr:
+                        //   T x;
+                        //   x{};
+                        // results in:
+                        //   T x;
+                        //   T & tmp;
+                        //   &tmp = &x, ?{}(tmp), tmp
+                        CommaExpr * commaExpr = new CommaExpr( assign, new CommaExpr( callExpr, new VariableExpr( tmp ) ) );
                         commaExpr->set_env( env );
-                        delete ctorExpr;
                         return commaExpr;
                 }