| 1 | // | 
|---|
| 2 | // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo | 
|---|
| 3 | // | 
|---|
| 4 | // The contents of this file are covered under the licence agreement in the | 
|---|
| 5 | // file "LICENCE" distributed with Cforall. | 
|---|
| 6 | // | 
|---|
| 7 | // CastCost.cc -- | 
|---|
| 8 | // | 
|---|
| 9 | // Author           : Richard C. Bilson | 
|---|
| 10 | // Created On       : Sun May 17 06:57:43 2015 | 
|---|
| 11 | // Last Modified By : Andrew Beach | 
|---|
| 12 | // Last Modified On : Tue Oct  4 15:00:00 2019 | 
|---|
| 13 | // Update Count     : 9 | 
|---|
| 14 | // | 
|---|
| 15 |  | 
|---|
| 16 | #include <cassert>                       // for assert | 
|---|
| 17 |  | 
|---|
| 18 | #include "AST/Print.hpp" | 
|---|
| 19 | #include "AST/SymbolTable.hpp" | 
|---|
| 20 | #include "AST/Type.hpp" | 
|---|
| 21 | #include "AST/TypeEnvironment.hpp" | 
|---|
| 22 | #include "ConversionCost.h"              // for ConversionCost | 
|---|
| 23 | #include "Cost.h"                        // for Cost, Cost::infinity | 
|---|
| 24 | #include "ResolvExpr/TypeEnvironment.h"  // for TypeEnvironment, EqvClass | 
|---|
| 25 | #include "SymTab/Indexer.h"              // for Indexer | 
|---|
| 26 | #include "SynTree/Declaration.h"         // for TypeDecl, NamedTypeDecl | 
|---|
| 27 | #include "SynTree/Type.h"                // for PointerType, Type, TypeInstType | 
|---|
| 28 | #include "typeops.h"                     // for typesCompatibleIgnoreQualifiers | 
|---|
| 29 |  | 
|---|
| 30 | #if 0 | 
|---|
| 31 | #define PRINT(x) x | 
|---|
| 32 | #else | 
|---|
| 33 | #define PRINT(x) | 
|---|
| 34 | #endif | 
|---|
| 35 |  | 
|---|
| 36 | namespace ResolvExpr { | 
|---|
| 37 | struct CastCost_old : public ConversionCost { | 
|---|
| 38 | public: | 
|---|
| 39 | CastCost_old( const Type * dest, bool srcIsLvalue, | 
|---|
| 40 | const SymTab::Indexer &indexer, const TypeEnvironment &env, CostFunction costFunc ); | 
|---|
| 41 |  | 
|---|
| 42 | using ConversionCost::previsit; | 
|---|
| 43 | using ConversionCost::postvisit; | 
|---|
| 44 | void postvisit( const BasicType * basicType ); | 
|---|
| 45 | void postvisit( const PointerType * pointerType ); | 
|---|
| 46 | }; | 
|---|
| 47 |  | 
|---|
| 48 | Cost castCost( const Type * src, const Type * dest, bool srcIsLvalue, | 
|---|
| 49 | const SymTab::Indexer &indexer, const TypeEnvironment &env ) { | 
|---|
| 50 | if ( const TypeInstType * destAsTypeInst = dynamic_cast< const TypeInstType * >( dest ) ) { | 
|---|
| 51 | if ( const EqvClass * eqvClass = env.lookup( destAsTypeInst->name ) ) { | 
|---|
| 52 | if ( eqvClass->type ) { | 
|---|
| 53 | return castCost( src, eqvClass->type, srcIsLvalue, indexer, env ); | 
|---|
| 54 | } else { | 
|---|
| 55 | return Cost::infinity; | 
|---|
| 56 | } | 
|---|
| 57 | } else if ( const NamedTypeDecl * namedType = indexer.lookupType( destAsTypeInst->name ) ) { | 
|---|
| 58 | // all typedefs should be gone by this point | 
|---|
| 59 | const TypeDecl * type = strict_dynamic_cast< const TypeDecl * >( namedType ); | 
|---|
| 60 | if ( type->base ) { | 
|---|
| 61 | return castCost( src, type->base, srcIsLvalue, indexer, env ) + Cost::safe; | 
|---|
| 62 | } // if | 
|---|
| 63 | } // if | 
|---|
| 64 | } // if | 
|---|
| 65 |  | 
|---|
| 66 | PRINT( | 
|---|
| 67 | std::cerr << "castCost ::: src is "; | 
|---|
| 68 | src->print( std::cerr ); | 
|---|
| 69 | std::cerr << std::endl << "dest is "; | 
|---|
| 70 | dest->print( std::cerr ); | 
|---|
| 71 | std::cerr << std::endl << "env is" << std::endl; | 
|---|
| 72 | env.print( std::cerr, 8 ); | 
|---|
| 73 | ) | 
|---|
| 74 |  | 
|---|
| 75 | if ( typesCompatibleIgnoreQualifiers( src, dest, indexer, env ) ) { | 
|---|
| 76 | PRINT( std::cerr << "compatible!" << std::endl; ) | 
|---|
| 77 | return Cost::zero; | 
|---|
| 78 | } else if ( dynamic_cast< const VoidType * >( dest ) ) { | 
|---|
| 79 | return Cost::safe; | 
|---|
| 80 | } else if ( const ReferenceType * refType = dynamic_cast< const ReferenceType * > ( dest ) ) { | 
|---|
| 81 | PRINT( std::cerr << "conversionCost: dest is reference" << std::endl; ) | 
|---|
| 82 | return convertToReferenceCost( src, refType, srcIsLvalue, indexer, env, [](const Type * t1, const Type * t2, const SymTab::Indexer & indexer, const TypeEnvironment & env ) { | 
|---|
| 83 | return ptrsCastable( t1, t2, env, indexer ); | 
|---|
| 84 | }); | 
|---|
| 85 | } else { | 
|---|
| 86 | PassVisitor<CastCost_old> converter( | 
|---|
| 87 | dest, srcIsLvalue, indexer, env, | 
|---|
| 88 | (Cost (*)( const Type *, const Type *, bool, const SymTab::Indexer &, const TypeEnvironment & )) | 
|---|
| 89 | castCost ); | 
|---|
| 90 | src->accept( converter ); | 
|---|
| 91 | if ( converter.pass.get_cost() == Cost::infinity ) { | 
|---|
| 92 | return Cost::infinity; | 
|---|
| 93 | } else { | 
|---|
| 94 | // xxx - why are we adding cost 0 here? | 
|---|
| 95 | return converter.pass.get_cost() + Cost::zero; | 
|---|
| 96 | } // if | 
|---|
| 97 | } // if | 
|---|
| 98 | } | 
|---|
| 99 |  | 
|---|
| 100 | CastCost_old::CastCost_old( const Type * dest, bool srcIsLvalue, | 
|---|
| 101 | const SymTab::Indexer &indexer, const TypeEnvironment &env, CostFunction costFunc ) | 
|---|
| 102 | : ConversionCost( dest, srcIsLvalue, indexer, env, costFunc ) { | 
|---|
| 103 | } | 
|---|
| 104 |  | 
|---|
| 105 | void CastCost_old::postvisit( const BasicType * basicType ) { | 
|---|
| 106 | const PointerType * destAsPointer = dynamic_cast< const PointerType * >( dest ); | 
|---|
| 107 | if ( destAsPointer && basicType->isInteger() ) { | 
|---|
| 108 | // necessary for, e.g. unsigned long => void * | 
|---|
| 109 | cost = Cost::unsafe; | 
|---|
| 110 | } else { | 
|---|
| 111 | cost = conversionCost( basicType, dest, srcIsLvalue, indexer, env ); | 
|---|
| 112 | } // if | 
|---|
| 113 | } | 
|---|
| 114 |  | 
|---|
| 115 | void CastCost_old::postvisit( const PointerType * pointerType ) { | 
|---|
| 116 | if ( const PointerType * destAsPtr = dynamic_cast< const PointerType * >( dest ) ) { | 
|---|
| 117 | if ( pointerType->tq <= destAsPtr->tq && typesCompatibleIgnoreQualifiers( pointerType->base, destAsPtr->base, indexer, env ) ) { | 
|---|
| 118 | cost = Cost::safe; | 
|---|
| 119 | } else { | 
|---|
| 120 | TypeEnvironment newEnv( env ); | 
|---|
| 121 | newEnv.add( pointerType->forall ); | 
|---|
| 122 | newEnv.add( pointerType->base->forall ); | 
|---|
| 123 | int castResult = ptrsCastable( pointerType->base, destAsPtr->base, newEnv, indexer ); | 
|---|
| 124 | if ( castResult > 0 ) { | 
|---|
| 125 | cost = Cost::safe; | 
|---|
| 126 | } else if ( castResult < 0 ) { | 
|---|
| 127 | cost = Cost::infinity; | 
|---|
| 128 | } // if | 
|---|
| 129 | } // if | 
|---|
| 130 | } else if ( const BasicType * destAsBasic = dynamic_cast< const BasicType * >( dest ) ) { | 
|---|
| 131 | if ( destAsBasic->isInteger() ) { | 
|---|
| 132 | // necessary for, e.g. void * => unsigned long | 
|---|
| 133 | cost = Cost::unsafe; | 
|---|
| 134 | } // if | 
|---|
| 135 | } | 
|---|
| 136 | } | 
|---|
| 137 |  | 
|---|
| 138 | namespace { | 
|---|
| 139 | struct CastCost_new : public ConversionCost_new { | 
|---|
| 140 | using ConversionCost_new::previsit; | 
|---|
| 141 | using ConversionCost_new::postvisit; | 
|---|
| 142 |  | 
|---|
| 143 | CastCost_new( | 
|---|
| 144 | const ast::Type * dst, bool srcIsLvalue, const ast::SymbolTable & symtab, | 
|---|
| 145 | const ast::TypeEnvironment & env, CostCalculation costFunc ) | 
|---|
| 146 | : ConversionCost_new( dst, srcIsLvalue, symtab, env, costFunc ) {} | 
|---|
| 147 |  | 
|---|
| 148 | void postvisit( const ast::BasicType * basicType ) { | 
|---|
| 149 | auto ptr = dynamic_cast< const ast::PointerType * >( dst ); | 
|---|
| 150 | if ( ptr && basicType->isInteger() ) { | 
|---|
| 151 | // needed for, e.g. unsigned long => void * | 
|---|
| 152 | cost = Cost::unsafe; | 
|---|
| 153 | } else { | 
|---|
| 154 | cost = conversionCost( basicType, dst, srcIsLvalue, symtab, env ); | 
|---|
| 155 | } | 
|---|
| 156 | } | 
|---|
| 157 |  | 
|---|
| 158 | void postvisit( const ast::PointerType * pointerType ) { | 
|---|
| 159 | if ( auto ptr = dynamic_cast< const ast::PointerType * >( dst ) ) { | 
|---|
| 160 | if ( | 
|---|
| 161 | pointerType->qualifiers <= ptr->qualifiers | 
|---|
| 162 | && typesCompatibleIgnoreQualifiers( pointerType->base, ptr->base, symtab, env ) | 
|---|
| 163 | ) { | 
|---|
| 164 | cost = Cost::safe; | 
|---|
| 165 | } else { | 
|---|
| 166 | ast::TypeEnvironment newEnv{ env }; | 
|---|
| 167 | if ( auto wParams = pointerType->base.as< ast::FunctionType >() ) { | 
|---|
| 168 | newEnv.add( wParams->forall ); | 
|---|
| 169 | } | 
|---|
| 170 | int castResult = ptrsCastable( pointerType->base, ptr->base, symtab, newEnv ); | 
|---|
| 171 | if ( castResult > 0 ) { | 
|---|
| 172 | cost = Cost::safe; | 
|---|
| 173 | } else if ( castResult < 0 ) { | 
|---|
| 174 | cost = Cost::infinity; | 
|---|
| 175 | } | 
|---|
| 176 | } | 
|---|
| 177 | } else if ( auto basic = dynamic_cast< const ast::BasicType * >( dst ) ) { | 
|---|
| 178 | if ( basic->isInteger() ) { | 
|---|
| 179 | // necessary for, e.g. void * => unsigned long | 
|---|
| 180 | cost = Cost::unsafe; | 
|---|
| 181 | } | 
|---|
| 182 | } | 
|---|
| 183 | } | 
|---|
| 184 | }; | 
|---|
| 185 |  | 
|---|
| 186 | #warning For overload resolution between the two versions. | 
|---|
| 187 | int localPtrsCastable(const ast::Type * t1, const ast::Type * t2, | 
|---|
| 188 | const ast::SymbolTable & symtab, const ast::TypeEnvironment & env ) { | 
|---|
| 189 | return ptrsCastable( t1, t2, symtab, env ); | 
|---|
| 190 | } | 
|---|
| 191 | Cost localCastCost( | 
|---|
| 192 | const ast::Type * src, const ast::Type * dst, bool srcIsLvalue, | 
|---|
| 193 | const ast::SymbolTable & symtab, const ast::TypeEnvironment & env | 
|---|
| 194 | ) { return castCost( src, dst, srcIsLvalue, symtab, env ); } | 
|---|
| 195 | } // anonymous namespace | 
|---|
| 196 |  | 
|---|
| 197 |  | 
|---|
| 198 |  | 
|---|
| 199 | Cost castCost( | 
|---|
| 200 | const ast::Type * src, const ast::Type * dst, bool srcIsLvalue, | 
|---|
| 201 | const ast::SymbolTable & symtab, const ast::TypeEnvironment & env | 
|---|
| 202 | ) { | 
|---|
| 203 | if ( auto typeInst = dynamic_cast< const ast::TypeInstType * >( dst ) ) { | 
|---|
| 204 | if ( const ast::EqvClass * eqvClass = env.lookup( *typeInst ) ) { | 
|---|
| 205 | // check cast cost against bound type, if present | 
|---|
| 206 | if ( eqvClass->bound ) { | 
|---|
| 207 | return castCost( src, eqvClass->bound, srcIsLvalue, symtab, env ); | 
|---|
| 208 | } else { | 
|---|
| 209 | return Cost::infinity; | 
|---|
| 210 | } | 
|---|
| 211 | } else if ( const ast::NamedTypeDecl * named = symtab.lookupType( typeInst->name ) ) { | 
|---|
| 212 | // all typedefs should be gone by now | 
|---|
| 213 | auto type = strict_dynamic_cast< const ast::TypeDecl * >( named ); | 
|---|
| 214 | if ( type->base ) { | 
|---|
| 215 | return castCost( src, type->base, srcIsLvalue, symtab, env ) + Cost::safe; | 
|---|
| 216 | } | 
|---|
| 217 | } | 
|---|
| 218 | } | 
|---|
| 219 |  | 
|---|
| 220 | PRINT( | 
|---|
| 221 | std::cerr << "castCost ::: src is "; | 
|---|
| 222 | ast::print( std::cerr, src ); | 
|---|
| 223 | std::cerr << std::endl << "dest is "; | 
|---|
| 224 | ast::print( std::cerr, dst ); | 
|---|
| 225 | std::cerr << std::endl << "env is" << std::endl; | 
|---|
| 226 | ast::print( std::cerr, env, 2 ); | 
|---|
| 227 | ) | 
|---|
| 228 |  | 
|---|
| 229 | if ( typesCompatibleIgnoreQualifiers( src, dst, symtab, env ) ) { | 
|---|
| 230 | PRINT( std::cerr << "compatible!" << std::endl; ) | 
|---|
| 231 | return Cost::zero; | 
|---|
| 232 | } else if ( dynamic_cast< const ast::VoidType * >( dst ) ) { | 
|---|
| 233 | return Cost::safe; | 
|---|
| 234 | } else if ( auto refType = dynamic_cast< const ast::ReferenceType * >( dst ) ) { | 
|---|
| 235 | PRINT( std::cerr << "conversionCost: dest is reference" << std::endl; ) | 
|---|
| 236 | #warning cast on ptrsCastable artifact of having two functions, remove when port done | 
|---|
| 237 | return convertToReferenceCost( | 
|---|
| 238 | src, refType, srcIsLvalue, symtab, env, localPtrsCastable ); | 
|---|
| 239 | } else { | 
|---|
| 240 | #warning cast on castCost artifact of having two functions, remove when port done | 
|---|
| 241 | ast::Pass< CastCost_new > converter( | 
|---|
| 242 | dst, srcIsLvalue, symtab, env, localCastCost ); | 
|---|
| 243 | src->accept( converter ); | 
|---|
| 244 | return converter.core.cost; | 
|---|
| 245 | } | 
|---|
| 246 | } | 
|---|
| 247 |  | 
|---|
| 248 | } // namespace ResolvExpr | 
|---|
| 249 |  | 
|---|
| 250 | // Local Variables: // | 
|---|
| 251 | // tab-width: 4 // | 
|---|
| 252 | // mode: c++ // | 
|---|
| 253 | // compile-command: "make install" // | 
|---|
| 254 | // End: // | 
|---|