| 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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| 7 | // CastCost.cc --
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| 8 | //
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| 9 | // Author : Richard C. Bilson
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| 10 | // Created On : Sun May 17 06:57:43 2015
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| 11 | // Last Modified By : Peter A. Buhr
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| 12 | // Last Modified On : Tue Feb 2 15:34:36 2016
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| 13 | // Update Count : 7
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| 14 | //
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| 15 |
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| 16 | #include <cassert> // for assert
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| 17 |
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| 18 | #include "ConversionCost.h" // for ConversionCost
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| 19 | #include "Cost.h" // for Cost, Cost::infinity
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| 20 | #include "ResolvExpr/TypeEnvironment.h" // for TypeEnvironment, EqvClass
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| 21 | #include "SymTab/Indexer.h" // for Indexer
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| 22 | #include "SynTree/Declaration.h" // for TypeDecl, NamedTypeDecl
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| 23 | #include "SynTree/Type.h" // for PointerType, Type, TypeInstType
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| 24 | #include "typeops.h" // for typesCompatibleIgnoreQualifiers
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| 25 |
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| 26 |
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| 27 | namespace ResolvExpr {
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| 28 | class CastCost : public ConversionCost {
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| 29 | public:
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| 30 | CastCost( Type *dest, const SymTab::Indexer &indexer, const TypeEnvironment &env );
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| 31 |
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| 32 | virtual void visit( BasicType *basicType );
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| 33 | virtual void visit( PointerType *pointerType );
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| 34 | };
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| 35 |
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| 36 | Cost castCost( Type *src, Type *dest, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
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| 37 | if ( TypeInstType *destAsTypeInst = dynamic_cast< TypeInstType* >( dest ) ) {
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| 38 | EqvClass eqvClass;
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| 39 | NamedTypeDecl *namedType;
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| 40 | if ( env.lookup( destAsTypeInst->get_name(), eqvClass ) ) {
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| 41 | if ( eqvClass.type ) {
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| 42 | return castCost( src, eqvClass.type, indexer, env );
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| 43 | } else {
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| 44 | return Cost::infinity;
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| 45 | }
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| 46 | } else if ( ( namedType = indexer.lookupType( destAsTypeInst->get_name() ) ) ) {
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| 47 | // all typedefs should be gone by this point
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| 48 | TypeDecl *type = strict_dynamic_cast< TypeDecl* >( namedType );
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| 49 | if ( type->get_base() ) {
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| 50 | return castCost( src, type->get_base(), indexer, env ) + Cost::safe;
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| 51 | } // if
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| 52 | } // if
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| 53 | } // if
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| 54 | if ( typesCompatibleIgnoreQualifiers( src, dest, indexer, env ) ) {
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| 55 | return Cost::zero;
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| 56 | } else if ( dynamic_cast< VoidType* >( dest ) ) {
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| 57 | return Cost::safe;
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| 58 | } else if ( ReferenceType * refType = dynamic_cast< ReferenceType * > ( dest ) ) {
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| 59 | return convertToReferenceCost( src, refType, indexer, env, [](Type * t1, Type * t2, const TypeEnvironment & env, const SymTab::Indexer & indexer) {
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| 60 | return ptrsCastable( t1, t2, env, indexer );
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| 61 | });
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| 62 | } else {
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| 63 | CastCost converter( dest, indexer, env );
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| 64 | src->accept( converter );
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| 65 | if ( converter.get_cost() == Cost::infinity ) {
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| 66 | return Cost::infinity;
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| 67 | } else {
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| 68 | // xxx - why are we adding cost 0 here?
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| 69 | return converter.get_cost() + Cost::zero;
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| 70 | } // if
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| 71 | } // if
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| 72 | }
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| 73 |
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| 74 | CastCost::CastCost( Type *dest, const SymTab::Indexer &indexer, const TypeEnvironment &env )
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| 75 | : ConversionCost( dest, indexer, env ) {
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| 76 | }
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| 77 |
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| 78 | void CastCost::visit( BasicType *basicType ) {
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| 79 | PointerType *destAsPointer = dynamic_cast< PointerType* >( dest );
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| 80 | if ( destAsPointer && basicType->isInteger() ) {
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| 81 | // necessary for, e.g. unsigned long => void*
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| 82 | cost = Cost::unsafe;
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| 83 | } else {
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| 84 | cost = conversionCost( basicType, dest, indexer, env );
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| 85 | } // if
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| 86 | }
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| 87 |
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| 88 | void CastCost::visit( PointerType *pointerType ) {
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| 89 | if ( PointerType *destAsPtr = dynamic_cast< PointerType* >( dest ) ) {
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| 90 | if ( pointerType->get_qualifiers() <= destAsPtr->get_qualifiers() && typesCompatibleIgnoreQualifiers( pointerType->get_base(), destAsPtr->get_base(), indexer, env ) ) {
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| 91 | cost = Cost::safe;
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| 92 | } else {
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| 93 | TypeEnvironment newEnv( env );
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| 94 | newEnv.add( pointerType->get_forall() );
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| 95 | newEnv.add( pointerType->get_base()->get_forall() );
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| 96 | int castResult = ptrsCastable( pointerType->get_base(), destAsPtr->get_base(), newEnv, indexer );
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| 97 | if ( castResult > 0 ) {
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| 98 | cost = Cost::safe;
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| 99 | } else if ( castResult < 0 ) {
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| 100 | cost = Cost::infinity;
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| 101 | } // if
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| 102 | } // if
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| 103 | } else if ( BasicType *destAsBasic = dynamic_cast< BasicType* >( dest ) ) {
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| 104 | if ( destAsBasic->isInteger() ) {
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| 105 | // necessary for, e.g. void* => unsigned long
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| 106 | cost = Cost::unsafe;
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| 107 | } // if
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| 108 | }
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| 109 | }
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| 110 | } // namespace ResolvExpr
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| 111 |
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| 112 | // Local Variables: //
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| 113 | // tab-width: 4 //
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| 114 | // mode: c++ //
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| 115 | // compile-command: "make install" //
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| 116 | // End: //
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