[51587aa] | 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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[906e24d] | 7 | // Lvalue.cc -- |
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[51587aa] | 8 | // |
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| 9 | // Author : Richard C. Bilson |
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| 10 | // Created On : Mon May 18 07:44:20 2015 |
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[01aeade] | 11 | // Last Modified By : Peter A. Buhr |
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[615a096] | 12 | // Last Modified On : Fri Mar 17 09:11:18 2017 |
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| 13 | // Update Count : 5 |
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[51587aa] | 14 | // |
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[51b7345] | 15 | |
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[08fc48f] | 16 | #include <cassert> // for safe_dynamic_cast |
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| 17 | #include <string> // for string |
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[51b7345] | 18 | |
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[08fc48f] | 19 | #include "Common/SemanticError.h" // for SemanticError |
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| 20 | #include "GenPoly.h" // for isPolyType |
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[51b7345] | 21 | #include "Lvalue.h" |
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[08fc48f] | 22 | #include "Parser/LinkageSpec.h" // for Spec, isBuiltin, Intrinsic |
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| 23 | #include "ResolvExpr/TypeEnvironment.h" // for AssertionSet, OpenVarSet |
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| 24 | #include "ResolvExpr/Unify.h" // for unify |
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| 25 | #include "SymTab/Indexer.h" // for Indexer |
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| 26 | #include "SynTree/Declaration.h" // for Declaration, FunctionDecl |
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| 27 | #include "SynTree/Expression.h" // for Expression, ConditionalExpr |
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| 28 | #include "SynTree/Mutator.h" // for mutateAll, Mutator |
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| 29 | #include "SynTree/Statement.h" // for ReturnStmt, Statement (ptr o... |
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| 30 | #include "SynTree/Type.h" // for PointerType, Type, FunctionType |
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| 31 | #include "SynTree/Visitor.h" // for Visitor, acceptAll |
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[51b7345] | 32 | |
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| 33 | namespace GenPoly { |
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[01aeade] | 34 | namespace { |
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[f8b961b] | 35 | /// Replace uses of lvalue returns with appropriate pointers |
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[01aeade] | 36 | class Pass1 : public Mutator { |
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| 37 | public: |
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| 38 | Pass1(); |
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[906e24d] | 39 | |
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[01aeade] | 40 | virtual Expression *mutate( ApplicationExpr *appExpr ); |
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| 41 | virtual Statement *mutate( ReturnStmt *appExpr ); |
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| 42 | virtual DeclarationWithType *mutate( FunctionDecl *funDecl ); |
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| 43 | private: |
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| 44 | DeclarationWithType* retval; |
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| 45 | }; |
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| 46 | |
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[f8b961b] | 47 | /// Replace declarations of lvalue returns with appropriate pointers |
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[01aeade] | 48 | class Pass2 : public Visitor { |
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| 49 | public: |
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| 50 | virtual void visit( FunctionType *funType ); |
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| 51 | private: |
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| 52 | }; |
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[b6fd751] | 53 | |
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| 54 | /// GCC-like Generalized Lvalues (which have since been removed from GCC) |
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| 55 | /// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues |
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| 56 | /// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c) |
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| 57 | class GeneralizedLvalue : public Mutator { |
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| 58 | typedef Mutator Parent; |
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| 59 | |
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[acd7c5dd] | 60 | virtual Expression * mutate( MemberExpr * memExpr ); |
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[b6fd751] | 61 | virtual Expression * mutate( AddressExpr * addressExpr ); |
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[acd7c5dd] | 62 | |
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| 63 | template<typename Func> |
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| 64 | Expression * applyTransformation( Expression * expr, Expression * arg, Func mkExpr ); |
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[b6fd751] | 65 | }; |
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[01aeade] | 66 | } // namespace |
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| 67 | |
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| 68 | void convertLvalue( std::list< Declaration* >& translationUnit ) { |
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| 69 | Pass1 p1; |
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| 70 | Pass2 p2; |
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[b6fd751] | 71 | GeneralizedLvalue genLval; |
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[01aeade] | 72 | mutateAll( translationUnit, p1 ); |
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| 73 | acceptAll( translationUnit, p2 ); |
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[b6fd751] | 74 | mutateAll( translationUnit, genLval ); |
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[01aeade] | 75 | } |
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| 76 | |
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[acd7c5dd] | 77 | Expression * generalizedLvalue( Expression * expr ) { |
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| 78 | GeneralizedLvalue genLval; |
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| 79 | return expr->acceptMutator( genLval ); |
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| 80 | } |
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| 81 | |
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[01aeade] | 82 | namespace { |
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[02ad3f5] | 83 | Type* isLvalueRet( FunctionType *function ) { |
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| 84 | if ( function->get_returnVals().empty() ) return 0; |
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| 85 | Type *ty = function->get_returnVals().front()->get_type(); |
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[615a096] | 86 | return ty->get_lvalue() ? ty : 0; |
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[01aeade] | 87 | } |
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| 88 | |
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| 89 | bool isIntrinsicApp( ApplicationExpr *appExpr ) { |
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| 90 | if ( VariableExpr *varExpr = dynamic_cast< VariableExpr* >( appExpr->get_function() ) ) { |
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| 91 | return varExpr->get_var()->get_linkage() == LinkageSpec::Intrinsic; |
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| 92 | } else { |
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| 93 | return false; |
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| 94 | } // if |
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| 95 | } |
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| 96 | |
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| 97 | Pass1::Pass1() { |
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| 98 | } |
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| 99 | |
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| 100 | DeclarationWithType * Pass1::mutate( FunctionDecl *funcDecl ) { |
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| 101 | if ( funcDecl->get_statements() ) { |
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| 102 | DeclarationWithType* oldRetval = retval; |
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| 103 | retval = 0; |
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| 104 | if ( ! LinkageSpec::isBuiltin( funcDecl->get_linkage() ) && isLvalueRet( funcDecl->get_functionType() ) ) { |
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| 105 | retval = funcDecl->get_functionType()->get_returnVals().front(); |
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| 106 | } |
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| 107 | // fix expressions and return statements in this function |
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| 108 | funcDecl->set_statements( funcDecl->get_statements()->acceptMutator( *this ) ); |
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| 109 | retval = oldRetval; |
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| 110 | } // if |
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| 111 | return funcDecl; |
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| 112 | } |
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| 113 | |
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| 114 | Expression * Pass1::mutate( ApplicationExpr *appExpr ) { |
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| 115 | appExpr->get_function()->acceptMutator( *this ); |
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| 116 | mutateAll( appExpr->get_args(), *this ); |
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| 117 | |
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[906e24d] | 118 | PointerType *pointer = safe_dynamic_cast< PointerType* >( appExpr->get_function()->get_result() ); |
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| 119 | FunctionType *function = safe_dynamic_cast< FunctionType* >( pointer->get_base() ); |
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[01aeade] | 120 | |
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[02ad3f5] | 121 | Type *funType = isLvalueRet( function ); |
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| 122 | if ( funType && ! isIntrinsicApp( appExpr ) ) { |
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| 123 | Expression *expr = appExpr; |
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[906e24d] | 124 | Type *appType = appExpr->get_result(); |
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[baba5d8] | 125 | if ( isPolyType( funType ) && ! isPolyType( appType ) ) { |
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[02ad3f5] | 126 | // make sure cast for polymorphic type is inside dereference |
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| 127 | expr = new CastExpr( appExpr, new PointerType( Type::Qualifiers(), appType->clone() ) ); |
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[baba5d8] | 128 | } |
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[01aeade] | 129 | UntypedExpr *deref = new UntypedExpr( new NameExpr( "*?" ) ); |
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[906e24d] | 130 | deref->set_result( appType->clone() ); |
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| 131 | appExpr->set_result( new PointerType( Type::Qualifiers(), appType ) ); |
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[02ad3f5] | 132 | deref->get_args().push_back( expr ); |
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[01aeade] | 133 | return deref; |
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| 134 | } else { |
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| 135 | return appExpr; |
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| 136 | } // if |
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| 137 | } |
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| 138 | |
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| 139 | Statement * Pass1::mutate(ReturnStmt *retStmt) { |
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| 140 | if ( retval && retStmt->get_expr() ) { |
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[615a096] | 141 | if ( retStmt->get_expr()->get_result()->get_lvalue() ) { |
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[cf16f94] | 142 | // ***** Code Removal ***** because casts may be stripped already |
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| 143 | |
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| 144 | // strip casts because not allowed to take address of cast |
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| 145 | // while ( CastExpr *castExpr = dynamic_cast< CastExpr* >( retStmt->get_expr() ) ) { |
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| 146 | // retStmt->set_expr( castExpr->get_arg() ); |
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| 147 | // retStmt->get_expr()->set_env( castExpr->get_env() ); |
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| 148 | // castExpr->set_env( 0 ); |
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| 149 | // castExpr->set_arg( 0 ); |
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| 150 | // delete castExpr; |
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| 151 | // } // while |
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[01aeade] | 152 | retStmt->set_expr( new AddressExpr( retStmt->get_expr()->acceptMutator( *this ) ) ); |
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| 153 | } else { |
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| 154 | throw SemanticError( "Attempt to return non-lvalue from an lvalue-qualified function" ); |
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| 155 | } // if |
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| 156 | } // if |
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| 157 | return retStmt; |
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| 158 | } |
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| 159 | |
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| 160 | void Pass2::visit( FunctionType *funType ) { |
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| 161 | std::string typeName; |
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| 162 | if ( isLvalueRet( funType ) ) { |
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| 163 | DeclarationWithType *retParm = funType->get_returnVals().front(); |
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| 164 | |
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| 165 | // make a new parameter that is a pointer to the type of the old return value |
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| 166 | retParm->set_type( new PointerType( Type::Qualifiers(), retParm->get_type() ) ); |
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| 167 | } // if |
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[906e24d] | 168 | |
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[01aeade] | 169 | Visitor::visit( funType ); |
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| 170 | } |
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[b6fd751] | 171 | |
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[acd7c5dd] | 172 | template<typename Func> |
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| 173 | Expression * GeneralizedLvalue::applyTransformation( Expression * expr, Expression * arg, Func mkExpr ) { |
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| 174 | if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( arg ) ) { |
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[b6fd751] | 175 | Expression * arg1 = commaExpr->get_arg1()->clone(); |
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| 176 | Expression * arg2 = commaExpr->get_arg2()->clone(); |
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[acd7c5dd] | 177 | Expression * ret = new CommaExpr( arg1, mkExpr( arg2 ) ); |
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| 178 | ret->set_env( expr->get_env() ); |
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| 179 | expr->set_env( nullptr ); |
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| 180 | delete expr; |
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| 181 | return ret->acceptMutator( *this ); |
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| 182 | } else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( arg ) ) { |
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[b6fd751] | 183 | Expression * arg1 = condExpr->get_arg1()->clone(); |
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| 184 | Expression * arg2 = condExpr->get_arg2()->clone(); |
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| 185 | Expression * arg3 = condExpr->get_arg3()->clone(); |
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[acd7c5dd] | 186 | ConditionalExpr * ret = new ConditionalExpr( arg1, mkExpr( arg2 ), mkExpr( arg3 ) ); |
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| 187 | ret->set_env( expr->get_env() ); |
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| 188 | expr->set_env( nullptr ); |
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| 189 | delete expr; |
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| 190 | |
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| 191 | // conditional expr type may not be either of the argument types, need to unify |
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| 192 | using namespace ResolvExpr; |
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| 193 | Type* commonType = nullptr; |
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| 194 | TypeEnvironment newEnv; |
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| 195 | AssertionSet needAssertions, haveAssertions; |
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| 196 | OpenVarSet openVars; |
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| 197 | unify( ret->get_arg2()->get_result(), ret->get_arg3()->get_result(), newEnv, needAssertions, haveAssertions, openVars, SymTab::Indexer(), commonType ); |
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| 198 | ret->set_result( commonType ? commonType : ret->get_arg2()->get_result()->clone() ); |
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| 199 | return ret->acceptMutator( *this ); |
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[b6fd751] | 200 | } |
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[acd7c5dd] | 201 | return expr; |
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| 202 | } |
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| 203 | |
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| 204 | Expression * GeneralizedLvalue::mutate( MemberExpr * memExpr ) { |
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| 205 | Parent::mutate( memExpr ); |
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| 206 | return applyTransformation( memExpr, memExpr->get_aggregate(), [=]( Expression * aggr ) { return new MemberExpr( memExpr->get_member(), aggr ); } ); |
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| 207 | } |
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| 208 | |
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| 209 | Expression * GeneralizedLvalue::mutate( AddressExpr * addrExpr ) { |
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| 210 | addrExpr = safe_dynamic_cast< AddressExpr * >( Parent::mutate( addrExpr ) ); |
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| 211 | return applyTransformation( addrExpr, addrExpr->get_arg(), []( Expression * arg ) { return new AddressExpr( arg ); } ); |
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[b6fd751] | 212 | } |
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[01aeade] | 213 | } // namespace |
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[51b7345] | 214 | } // namespace GenPoly |
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[01aeade] | 215 | |
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[51587aa] | 216 | // Local Variables: // |
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| 217 | // tab-width: 4 // |
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| 218 | // mode: c++ // |
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| 219 | // compile-command: "make install" // |
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| 220 | // End: // |
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