Changes in src/GenPoly/Specialize.cc [8cbf8cd:698664b3]

File:

• src/GenPoly/Specialize.cc (modified) (7 diffs)

src/GenPoly/Specialize.cc

@@ -9 +9 @@
 // Author           : Richard C. Bilson
 // Created On       : Mon May 18 07:44:20 2015
-// Last Modified By : Rob Schluntz
-// Last Modified On : Tue Sep 22 14:04:13 2015
-// Update Count     : 15
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Sat Jun 13 15:54:07 2015
+// Update Count     : 6
 //
 
@@ -45 +45 @@
 
           private:
+                Expression *createThunkFunction( FunctionType *funType, Expression *actual, InferredParams *inferParams = 0 );
                 Expression *doSpecialization( Type *formalType, Expression *actual, InferredParams *inferParams = 0 );
                 void handleExplicitParams( ApplicationExpr *appExpr );
@@ -61 +62 @@
         }
 
+        /// Looks up open variables in actual type, returning true if any of them are bound in the environment or formal type.
         bool needsSpecialization( Type *formalType, Type *actualType, TypeSubstitution *env ) {
                 if ( env ) {
@@ -85 +87 @@
         }
 
+        /// Returns a pointer to the base FunctionType if ty is the type of a function (or pointer to one), NULL otherwise
+        FunctionType * getFunctionType( Type *ty ) {
+                PointerType *ptrType;
+                if ( ( ptrType = dynamic_cast< PointerType* >( ty ) ) ) {
+                        return dynamic_cast< FunctionType* >( ptrType->get_base() ); // pointer if FunctionType, NULL otherwise
+                } else {
+                        return dynamic_cast< FunctionType* >( ty ); // pointer if FunctionType, NULL otherwise
+                }
+        }
+
+        /// Generates a thunk that calls `actual` with type `funType` and returns its address
+        Expression * Specialize::createThunkFunction( FunctionType *funType, Expression *actual, InferredParams *inferParams ) {
+                FunctionType *newType = funType->clone();
+                if ( env ) {
+                        TypeSubstitution newEnv( *env );
+                        // it is important to replace only occurrences of type variables that occur free in the
+                        // thunk's type
+                        newEnv.applyFree( newType );
+                } // if
+                // create new thunk with same signature as formal type (C linkage, empty body)
+                FunctionDecl *thunkFunc = new FunctionDecl( thunkNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, newType, new CompoundStmt( std::list< std::string >() ), false, false );
+                thunkFunc->fixUniqueId();
+
+                // thread thunk parameters into call to actual function, naming thunk parameters as we go
+                UniqueName paramNamer( paramPrefix );
+                ApplicationExpr *appExpr = new ApplicationExpr( actual );
+                for ( std::list< DeclarationWithType* >::iterator param = thunkFunc->get_functionType()->get_parameters().begin(); param != thunkFunc->get_functionType()->get_parameters().end(); ++param ) {
+                        (*param )->set_name( paramNamer.newName() );
+                        appExpr->get_args().push_back( new VariableExpr( *param ) );
+                } // for
+                appExpr->set_env( maybeClone( env ) );
+                if ( inferParams ) {
+                        appExpr->get_inferParams() = *inferParams;
+                } // if
+
+                // handle any specializations that may still be present
+                std::string oldParamPrefix = paramPrefix;
+                paramPrefix += "p";
+                // save stmtsToAdd in oldStmts
+                std::list< Statement* > oldStmts;
+                oldStmts.splice( oldStmts.end(), stmtsToAdd );
+                handleExplicitParams( appExpr );
+                paramPrefix = oldParamPrefix;
+                // write any statements added for recursive specializations into the thunk body
+                thunkFunc->get_statements()->get_kids().splice( thunkFunc->get_statements()->get_kids().end(), stmtsToAdd );
+                // restore oldStmts into stmtsToAdd
+                stmtsToAdd.splice( stmtsToAdd.end(), oldStmts );
+
+                // add return (or valueless expression) to the thunk
+                Statement *appStmt;
+                if ( funType->get_returnVals().empty() ) {
+                        appStmt = new ExprStmt( noLabels, appExpr );
+                } else {
+                        appStmt = new ReturnStmt( noLabels, appExpr );
+                } // if
+                thunkFunc->get_statements()->get_kids().push_back( appStmt );
+
+                // add thunk definition to queue of statements to add
+                stmtsToAdd.push_back( new DeclStmt( noLabels, thunkFunc ) );
+                // return address of thunk function as replacement expression
+                return new AddressExpr( new VariableExpr( thunkFunc ) );
+        }
+        
         Expression * Specialize::doSpecialization( Type *formalType, Expression *actual, InferredParams *inferParams ) {
-                assert( ! actual->get_results().empty() );
                 if ( needsSpecialization( formalType, actual->get_results().front(), env ) ) {
-                        PointerType *ptrType;
                         FunctionType *funType;
-                        if ( ( ptrType = dynamic_cast< PointerType* >( formalType ) ) && ( funType = dynamic_cast< FunctionType* >( ptrType->get_base() ) ) ) {
-                                FunctionType *newType = funType->clone();
-                                if ( env ) {
-                                        TypeSubstitution newEnv( *env );
-                                        // it is important to replace only occurrences of type variables that occur free in the
-                                        // thunk's type
-                                        newEnv.applyFree( newType );
-                                } // if
-                                FunctionDecl *thunkFunc = new FunctionDecl( thunkNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, newType, new CompoundStmt( std::list< std::string >() ), false, false );
-                                thunkFunc->fixUniqueId();
-
-                                UniqueName paramNamer( paramPrefix );
-                                ApplicationExpr *appExpr = new ApplicationExpr( actual );
-                                for ( std::list< DeclarationWithType* >::iterator param = thunkFunc->get_functionType()->get_parameters().begin(); param != thunkFunc->get_functionType()->get_parameters().end(); ++param ) {
-                                        (*param )->set_name( paramNamer.newName() );
-                                        appExpr->get_args().push_back( new VariableExpr( *param ) );
-                                } // for
-                                appExpr->set_env( maybeClone( env ) );
-                                if ( inferParams ) {
-                                        appExpr->get_inferParams() = *inferParams;
-                                } // if
-
-                                // handle any specializations that may still be present
-                                std::string oldParamPrefix = paramPrefix;
-                                paramPrefix += "p";
-                                std::list< Statement* > oldStmts;
-                                oldStmts.splice( oldStmts.end(), stmtsToAdd );
-                                handleExplicitParams( appExpr );
-                                paramPrefix = oldParamPrefix;
-                                thunkFunc->get_statements()->get_kids().splice( thunkFunc->get_statements()->get_kids().end(), stmtsToAdd );
-                                stmtsToAdd.splice( stmtsToAdd.end(), oldStmts );
-
-                                Statement *appStmt;
-                                if ( funType->get_returnVals().empty() ) {
-                                        appStmt = new ExprStmt( noLabels, appExpr );
+                        if ( ( funType = getFunctionType( formalType ) ) ) {
+                                ApplicationExpr *appExpr;
+                                VariableExpr *varExpr;
+                                if ( ( appExpr = dynamic_cast<ApplicationExpr*>( actual ) ) ) {
+                                        return createThunkFunction( funType, appExpr->get_function(), inferParams );
+                                } else if ( ( varExpr = dynamic_cast<VariableExpr*>( actual ) ) ) {
+                                        return createThunkFunction( funType, varExpr, inferParams );
                                 } else {
-                                        appStmt = new ReturnStmt( noLabels, appExpr );
-                                } // if
-                                thunkFunc->get_statements()->get_kids().push_back( appStmt );
-                                stmtsToAdd.push_back( new DeclStmt( noLabels, thunkFunc ) );
-                                return new AddressExpr( new VariableExpr( thunkFunc ) );
+                                        // This likely won't work, as anything that could build an ApplicationExpr probably hit one of the previous two branches
+                                        return createThunkFunction( funType, actual, inferParams );
+                                }
                         } else {
                                 return actual;
@@ -142 +175 @@
                 // create thunks for the explicit parameters
                 assert( ! appExpr->get_function()->get_results().empty() );
-                PointerType *pointer = dynamic_cast< PointerType* >( appExpr->get_function()->get_results().front() );
-                assert( pointer );
-                FunctionType *function = dynamic_cast< FunctionType* >( pointer->get_base() );
+                FunctionType *function = getFunctionType( appExpr->get_function()->get_results().front() );
+                assert( function );
                 std::list< DeclarationWithType* >::iterator formal;
                 std::list< Expression* >::iterator actual;
@@ -168 +200 @@
         Expression * Specialize::mutate( AddressExpr *addrExpr ) {
                 addrExpr->get_arg()->acceptMutator( *this );
-                assert( ! addrExpr->get_results().empty() );
                 addrExpr->set_arg( doSpecialization( addrExpr->get_results().front(), addrExpr->get_arg() ) );
                 return addrExpr;
@@ -175 +206 @@
         Expression * Specialize::mutate( CastExpr *castExpr ) {
                 castExpr->get_arg()->acceptMutator( *this );
-                if ( ! castExpr->get_results().empty() ) {
-                        // this may not be the correct condition, but previously the next statement 
-                        // was happening unchecked, causing a crash on a cast to void
-                        castExpr->set_arg( doSpecialization( castExpr->get_results().front(), castExpr->get_arg() ) );          
-                }
-                return castExpr;
+                Expression *specialized = doSpecialization( castExpr->get_results().front(), castExpr->get_arg() );
+                if ( specialized != castExpr->get_arg() ) {
+                        // assume here that the specialization incorporates the cast
+                        return specialized;
+                } else {
+                        return castExpr;
+                }
         }