Changes in src/GenPoly/Lvalue.cc [1d776fd:8ca3a72]

File:

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

src/GenPoly/Lvalue.cc

@@ -32 +32 @@
 #include "Common/UniqueName.h"
 #include "Common/utility.h"
-#include "InitTweak/InitTweak.h"
-
-#include "Common/PassVisitor.h"
-
-// need to be careful about polymorphic references... e.g. in *? (___operator_deref__A0_1_0_0__Fd0_Pd0_intrinsic___1)
-// the variable is automatically dereferenced and this causes errors dereferencing void*.
 
 namespace GenPoly {
         namespace {
-                struct ReferenceConversions final {
-                        Expression * postmutate( CastExpr * castExpr );
+                /// Replace uses of lvalue returns with appropriate pointers
+                class Pass1 : public Mutator {
+                  public:
+                        Pass1();
+
+                        virtual Expression *mutate( ApplicationExpr *appExpr );
+                        virtual Statement *mutate( ReturnStmt *appExpr );
+                        virtual DeclarationWithType *mutate( FunctionDecl *funDecl );
+                  private:
+                        DeclarationWithType* retval;
                 };
 
-                /// Intrinsic functions that take reference parameters don't REALLY take reference parameters -- their reference arguments must always be implicitly dereferenced.
-                struct FixIntrinsicArgs final {
-                        Expression * postmutate( ApplicationExpr *appExpr );
-                };
-
-
-                /// Replace reference types with pointer types
-                struct ReferenceTypeElimination final {
-                        Type * postmutate( ReferenceType * refType );
+                /// Replace declarations of lvalue returns with appropriate pointers
+                class Pass2 : public Visitor {
+                  public:
+                        virtual void visit( FunctionType *funType );
+                  private:
                 };
 
@@ -59 +57 @@
                 /// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues
                 /// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c)
-                struct GeneralizedLvalue final {
-                        Expression * postmutate( AddressExpr * addressExpr );
+                class GeneralizedLvalue : public Mutator {
+                        typedef Mutator Parent;
+
+                        virtual Expression * mutate( AddressExpr * addressExpr );
                 };
         } // namespace
 
         void convertLvalue( std::list< Declaration* >& translationUnit ) {
-                std::cerr << "convertLvalue" << std::endl;
-                PassVisitor<ReferenceConversions> refCvt;
-                PassVisitor<ReferenceTypeElimination> elim;
-                PassVisitor<GeneralizedLvalue> genLval;
-                PassVisitor<FixIntrinsicArgs> fixer;
-                mutateAll( translationUnit, refCvt );
-                mutateAll( translationUnit, fixer );
-                mutateAll( translationUnit, elim );
+                Pass1 p1;
+                Pass2 p2;
+                GeneralizedLvalue genLval;
+                mutateAll( translationUnit, p1 );
+                acceptAll( translationUnit, p2 );
                 mutateAll( translationUnit, genLval );
         }
@@ -80 +77 @@
                         if ( function->get_returnVals().empty() ) return 0;
                         Type *ty = function->get_returnVals().front()->get_type();
-                        return dynamic_cast< ReferenceType * >( ty ) ;
+                        return ty->get_lvalue() ? ty : 0;
                 }
 
@@ -91 +88 @@
                 }
 
-                bool isDeref( Expression * expr ) {
-                        if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) {
-                                return InitTweak::getFunctionName( untyped ) == "*?";
-                        } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
-                                if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) {
-                                        return func->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getFunctionName( appExpr ) == "*?";
-                                }
-                        }
-                        return false;
+                Pass1::Pass1() {
                 }
 
-                bool isIntrinsicReference( Expression * expr ) {
-                        if ( isDeref( expr ) ) return true;
-                        else if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) {
-                                return InitTweak::getFunctionName( untyped ) == "?[?]";
-                        } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
-                                if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) {
-                                        return func->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getFunctionName( appExpr ) == "?[?]";
+                DeclarationWithType * Pass1::mutate( FunctionDecl *funcDecl ) {
+                        if ( funcDecl->get_statements() ) {
+                                DeclarationWithType* oldRetval = retval;
+                                retval = 0;
+                                if ( ! LinkageSpec::isBuiltin( funcDecl->get_linkage() ) && isLvalueRet( funcDecl->get_functionType() ) ) {
+                                        retval = funcDecl->get_functionType()->get_returnVals().front();
                                 }
-                        }
-                        return false;
+                                // fix expressions and return statements in this function
+                                funcDecl->set_statements( funcDecl->get_statements()->acceptMutator( *this ) );
+                                retval = oldRetval;
+                        } // if
+                        return funcDecl;
                 }
 
-                void fixArg( Expression *& arg, Type * formal ) {
-                        // if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( arg ) ) {
-                                if ( dynamic_cast<ReferenceType*>( formal ) ) { // xxx - but might be deref, in which case result isn't REALLY a reference, at least not in the sense that we need to add another deref...
-                                        // doesn't work, for some reason left arg is skipped in assign
-                                        ReferenceType * refType = safe_dynamic_cast< ReferenceType * >( arg->get_result() ) ;
-                                        std::cerr << "appexpr arg is non-deref/index intrinsic call" << std::endl;
-                                        std::cerr << arg << std::endl;
-                                        PointerType * ptrType = new PointerType( Type::Qualifiers(), refType->get_base()->clone() );
-                                        delete refType;
-                                        arg->set_result( ptrType );
-                                        arg = UntypedExpr::createDeref( arg );
+                Expression * Pass1::mutate( ApplicationExpr *appExpr ) {
+                        appExpr->get_function()->acceptMutator( *this );
+                        mutateAll( appExpr->get_args(), *this );
+
+                        PointerType *pointer = safe_dynamic_cast< PointerType* >( appExpr->get_function()->get_result() );
+                        FunctionType *function = safe_dynamic_cast< FunctionType* >( pointer->get_base() );
+
+                        Type *funType = isLvalueRet( function );
+                        if ( funType && ! isIntrinsicApp( appExpr ) ) {
+                                Expression *expr = appExpr;
+                                Type *appType = appExpr->get_result();
+                                if ( isPolyType( funType ) && ! isPolyType( appType ) ) {
+                                        // make sure cast for polymorphic type is inside dereference
+                                        expr = new CastExpr( appExpr, new PointerType( Type::Qualifiers(), appType->clone() ) );
                                 }
-
-                        // }
+                                UntypedExpr *deref = new UntypedExpr( new NameExpr( "*?" ) );
+                                deref->set_result( appType->clone() );
+                                appExpr->set_result( new PointerType( Type::Qualifiers(), appType ) );
+                                deref->get_args().push_back( expr );
+                                return deref;
+                        } else {
+                                return appExpr;
+                        } // if
                 }
 
-                Expression * FixIntrinsicArgs::postmutate( ApplicationExpr * appExpr ) {
-                        if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
-                                if ( function->get_linkage() == LinkageSpec::Intrinsic ) { // intrinsic functions that turn pointers into references
-                                        FunctionType * ftype = GenPoly::getFunctionType( function->get_type() );
-                                        assertf( ftype, "Function declaration does not have function type." );
-                                        for ( auto p : group_iterate( appExpr->get_args(), ftype->get_parameters() ) ) {
-                                                Expression *& arg = std::get<0>( p );
-                                                DeclarationWithType * formal = std::get<1>( p );
-                                                std::cerr << "pair<0>: " << arg << std::endl;
-                                                std::cerr << "pair<1>: " << formal->get_type() << std::endl;
-                                                if ( isIntrinsicReference( arg ) ) {
-                                                        std::cerr << "skipping intrinsic reference" << std::endl;
-                                                        continue;
-                                                } else {
-                                                        fixArg( arg, formal->get_type() );
-                                                }
-                                        }
-                                }
-                        }
-                        return appExpr;
+                Statement * Pass1::mutate(ReturnStmt *retStmt) {
+                        if ( retval && retStmt->get_expr() ) {
+                                if ( retStmt->get_expr()->get_result()->get_lvalue() ) {
+                                        // ***** Code Removal ***** because casts may be stripped already
+
+                                        // strip casts because not allowed to take address of cast
+                                        // while ( CastExpr *castExpr = dynamic_cast< CastExpr* >( retStmt->get_expr() ) ) {
+                                        //      retStmt->set_expr( castExpr->get_arg() );
+                                        //      retStmt->get_expr()->set_env( castExpr->get_env() );
+                                        //      castExpr->set_env( 0 );
+                                        //      castExpr->set_arg( 0 );
+                                        //      delete castExpr;
+                                        // } // while
+                                        retStmt->set_expr( new AddressExpr( retStmt->get_expr()->acceptMutator( *this ) ) );
+                                } else {
+                                        throw SemanticError( "Attempt to return non-lvalue from an lvalue-qualified function" );
+                                } // if
+                        } // if
+                        return retStmt;
                 }
 
-                Expression * ReferenceConversions::postmutate( CastExpr * castExpr ) {
-                        // conversion to reference type
-                        if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( castExpr->get_result() ) ) {
-                                (void)refType;
-                                if ( ReferenceType * otherRef = dynamic_cast< ReferenceType * >( castExpr->get_arg()->get_result() ) ) {
-                                        // nothing to do if casting from reference to reference.
-                                        (void)otherRef;
-                                        std::cerr << "convert reference to reference -- nop" << std::endl;
-                                        if ( isIntrinsicReference( castExpr->get_arg() ) ) {
-                                                Expression * callExpr = castExpr->get_arg();
-                                                Expression ** arg = nullptr;
-                                                Expression *& arg0 = InitTweak::getCallArg( callExpr, 0 );
-                                                if ( dynamic_cast<PointerType *>( arg0->get_result() ) ) {
-                                                        arg = &arg0;
-                                                } else {
-                                                        arg = &InitTweak::getCallArg( callExpr, 1 );
-                                                }
+                void Pass2::visit( FunctionType *funType ) {
+                        std::string typeName;
+                        if ( isLvalueRet( funType ) ) {
+                                DeclarationWithType *retParm = funType->get_returnVals().front();
 
-                                                castExpr->set_arg( *arg );
-                                                *arg = castExpr;
-                                                std::cerr << "but arg is deref -- &" << std::endl;
-                                                std::cerr << callExpr << std::endl;
-                                                // castExpr->set_arg( new AddressExpr( castExpr->get_arg() ) );
+                                // make a new parameter that is a pointer to the type of the old return value
+                                retParm->set_type( new PointerType( Type::Qualifiers(), retParm->get_type() ) );
+                        } // if
 
-                                                // move environment out to new top-level
-                                                callExpr->set_env( castExpr->get_env() );
-                                                castExpr->set_env( nullptr );
-                                                return callExpr;
-                                        }
-                                        std::cerr << castExpr << std::endl;
-                                        return castExpr;
-                                } else if ( castExpr->get_arg()->get_result()->get_lvalue() ) {
-                                        // conversion from lvalue to reference
-                                        // xxx - keep cast, but turn into pointer cast??
-                                        // xxx - memory
-                                        std::cerr << "convert lvalue to reference -- &" << std::endl;
-                                        std::cerr << castExpr->get_arg() << std::endl;
-                                        castExpr->set_arg( new AddressExpr( castExpr->get_arg() ) );
-                                        // return new AddressExpr( castExpr->get_arg() );
-                                        return castExpr;
-                                } else {
-                                        // rvalue to reference conversion -- introduce temporary
-                                }
-                                assertf( false, "Only conversions to reference from lvalue are currently supported: %s", toString( castExpr ).c_str() );
-                        } else if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( castExpr->get_arg()->get_result() ) ) {
-                                // should be easy, just need to move deref code up here?
-                                std::cerr << "convert reference to rvalue -- *" << std::endl;
-                                if ( isIntrinsicReference( castExpr->get_arg() ) ) {
-                                        std::cerr << "but arg is intrinsic reference -- nop" << std::endl;
-                                        return castExpr;
-                                }
-                                std::cerr << castExpr << std::endl;
-
-                                PointerType * ptrType = new PointerType( refType->get_qualifiers(), refType->get_base()->clone() );
-                                delete castExpr->get_result();
-                                castExpr->set_result( ptrType );
-                                Expression * deref = UntypedExpr::createDeref( castExpr );
-                                deref->set_env( castExpr->get_env() );
-                                castExpr->set_env( nullptr );
-                                return deref;
-                                // assertf( false, "Conversions from reference types are not currently supported." );
-                        }
-                        return castExpr;
+                        Visitor::visit( funType );
                 }
 
-                Type * ReferenceTypeElimination::postmutate( ReferenceType * refType ) {
-                        Type * base = refType->get_base();
-                        refType->set_base( nullptr );
-                        delete refType;
-                        return new PointerType( Type::Qualifiers(), base );
-                }
-
-                Expression * GeneralizedLvalue::postmutate( AddressExpr * addrExpr ) {
+                Expression * GeneralizedLvalue::mutate( AddressExpr * addrExpr ) {
+                        addrExpr = safe_dynamic_cast< AddressExpr * >( Parent::mutate( addrExpr ) );
                         if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( addrExpr->get_arg() ) ) {
                                 Expression * arg1 = commaExpr->get_arg1()->clone();