Changes in src/GenPoly/Lvalue.cc [9aaac6e9:08fc48f]
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src/GenPoly/Lvalue.cc
r9aaac6e9 r08fc48f 17 17 #include <string> // for string 18 18 19 #include "Common/PassVisitor.h"20 19 #include "Common/SemanticError.h" // for SemanticError 21 20 #include "GenPoly.h" // for isPolyType 22 21 #include "Lvalue.h" 23 24 22 #include "Parser/LinkageSpec.h" // for Spec, isBuiltin, Intrinsic 25 23 #include "ResolvExpr/TypeEnvironment.h" // for AssertionSet, OpenVarSet 26 24 #include "ResolvExpr/Unify.h" // for unify 27 #include "ResolvExpr/typeops.h"28 #include "SymTab/Autogen.h"29 25 #include "SymTab/Indexer.h" // for Indexer 30 26 #include "SynTree/Declaration.h" // for Declaration, FunctionDecl … … 35 31 #include "SynTree/Visitor.h" // for Visitor, acceptAll 36 32 37 #if 038 #define PRINT(x) x39 #else40 #define PRINT(x)41 #endif42 43 33 namespace GenPoly { 44 34 namespace { 45 // TODO: fold this into the general createDeref function?? 46 Expression * mkDeref( Expression * arg ) { 47 if ( SymTab::dereferenceOperator ) { 48 VariableExpr * deref = new VariableExpr( SymTab::dereferenceOperator ); 49 deref->set_result( new PointerType( Type::Qualifiers(), deref->get_result() ) ); 50 Type * base = InitTweak::getPointerBase( arg->get_result() ); 51 assertf( base, "expected pointer type in dereference (type was %s)", toString( arg->get_result() ).c_str() ); 52 ApplicationExpr * ret = new ApplicationExpr( deref, { arg } ); 53 delete ret->get_result(); 54 ret->set_result( base->clone() ); 55 ret->get_result()->set_lvalue( true ); 56 return ret; 57 } else { 58 return UntypedExpr::createDeref( arg ); 59 } 60 } 61 62 struct ReferenceConversions final { 63 Expression * postmutate( CastExpr * castExpr ); 64 Expression * postmutate( AddressExpr * addrExpr ); 35 /// Replace uses of lvalue returns with appropriate pointers 36 class Pass1 : public Mutator { 37 public: 38 Pass1(); 39 40 virtual Expression *mutate( ApplicationExpr *appExpr ); 41 virtual Statement *mutate( ReturnStmt *appExpr ); 42 virtual DeclarationWithType *mutate( FunctionDecl *funDecl ); 43 private: 44 DeclarationWithType* retval; 65 45 }; 66 46 67 /// Intrinsic functions that take reference parameters don't REALLY take reference parameters -- their reference arguments must always be implicitly dereferenced. 68 struct FixIntrinsicArgs final { 69 Expression * postmutate( ApplicationExpr * appExpr ); 70 }; 71 72 struct FixIntrinsicResult final : public WithGuards { 73 Expression * postmutate( ApplicationExpr * appExpr ); 74 void premutate( FunctionDecl * funcDecl ); 75 bool inIntrinsic = false; 76 }; 77 78 /// Replace reference types with pointer types 79 struct ReferenceTypeElimination final { 80 Type * postmutate( ReferenceType * refType ); 47 /// Replace declarations of lvalue returns with appropriate pointers 48 class Pass2 : public Visitor { 49 public: 50 virtual void visit( FunctionType *funType ); 51 private: 81 52 }; 82 53 … … 84 55 /// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues 85 56 /// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c) 86 struct GeneralizedLvalue final : public WithVisitorRef<GeneralizedLvalue> { 87 Expression * postmutate( AddressExpr * addressExpr ); 88 Expression * postmutate( MemberExpr * memExpr ); 57 class GeneralizedLvalue : public Mutator { 58 typedef Mutator Parent; 59 60 virtual Expression * mutate( MemberExpr * memExpr ); 61 virtual Expression * mutate( AddressExpr * addressExpr ); 89 62 90 63 template<typename Func> 91 64 Expression * applyTransformation( Expression * expr, Expression * arg, Func mkExpr ); 92 65 }; 93 94 /// Removes redundant &*/*& pattern that this pass can generate95 struct CollapseAddrDeref final {96 Expression * postmutate( AddressExpr * addressExpr );97 Expression * postmutate( ApplicationExpr * appExpr );98 };99 100 struct AddrRef final : public WithGuards {101 void premutate( AddressExpr * addrExpr );102 Expression * postmutate( AddressExpr * addrExpr );103 void premutate( Expression * expr );104 105 bool first = true;106 bool current = false;107 int refDepth = 0;108 };109 66 } // namespace 110 67 111 static bool referencesEliminated = false; 112 // used by UntypedExpr::createDeref to determine whether result type of dereference should be ReferenceType or value type. 113 bool referencesPermissable() { 114 return ! referencesEliminated; 68 void convertLvalue( std::list< Declaration* >& translationUnit ) { 69 Pass1 p1; 70 Pass2 p2; 71 GeneralizedLvalue genLval; 72 mutateAll( translationUnit, p1 ); 73 acceptAll( translationUnit, p2 ); 74 mutateAll( translationUnit, genLval ); 115 75 } 116 76 117 void convertLvalue( std::list< Declaration* >& translationUnit ) {118 PassVisitor<ReferenceConversions> refCvt;119 PassVisitor<ReferenceTypeElimination> elim;120 PassVisitor<GeneralizedLvalue> genLval;121 PassVisitor<FixIntrinsicArgs> fixer;122 PassVisitor<CollapseAddrDeref> collapser;123 PassVisitor<AddrRef> addrRef;124 PassVisitor<FixIntrinsicResult> intrinsicResults;125 mutateAll( translationUnit, intrinsicResults );126 mutateAll( translationUnit, addrRef );127 mutateAll( translationUnit, refCvt );128 mutateAll( translationUnit, fixer );129 mutateAll( translationUnit, collapser );130 mutateAll( translationUnit, genLval );131 mutateAll( translationUnit, elim ); // last because other passes need reference types to work132 133 // from this point forward, no other pass should create reference types.134 referencesEliminated = true;135 }136 137 77 Expression * generalizedLvalue( Expression * expr ) { 138 PassVisitor<GeneralizedLvalue>genLval;78 GeneralizedLvalue genLval; 139 79 return expr->acceptMutator( genLval ); 140 80 } 141 81 142 82 namespace { 143 // true for intrinsic function calls that return a reference 144 bool isIntrinsicReference( Expression * expr ) { 145 if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) { 146 std::string fname = InitTweak::getFunctionName( untyped ); 147 // known intrinsic-reference prelude functions 148 return fname == "*?" || fname == "?[?]"; 149 } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) { 150 if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) { 151 // use type of return variable rather than expr result type, since it may have been changed to a pointer type 152 FunctionType * ftype = GenPoly::getFunctionType( func->get_type() ); 153 Type * ret = ftype->get_returnVals().empty() ? nullptr : ftype->get_returnVals().front()->get_type(); 154 return func->get_linkage() == LinkageSpec::Intrinsic && dynamic_cast<ReferenceType *>( ret ); 83 Type* isLvalueRet( FunctionType *function ) { 84 if ( function->get_returnVals().empty() ) return 0; 85 Type *ty = function->get_returnVals().front()->get_type(); 86 return ty->get_lvalue() ? ty : 0; 87 } 88 89 bool isIntrinsicApp( ApplicationExpr *appExpr ) { 90 if ( VariableExpr *varExpr = dynamic_cast< VariableExpr* >( appExpr->get_function() ) ) { 91 return varExpr->get_var()->get_linkage() == LinkageSpec::Intrinsic; 92 } else { 93 return false; 94 } // if 95 } 96 97 Pass1::Pass1() { 98 } 99 100 DeclarationWithType * Pass1::mutate( FunctionDecl *funcDecl ) { 101 if ( funcDecl->get_statements() ) { 102 DeclarationWithType* oldRetval = retval; 103 retval = 0; 104 if ( ! LinkageSpec::isBuiltin( funcDecl->get_linkage() ) && isLvalueRet( funcDecl->get_functionType() ) ) { 105 retval = funcDecl->get_functionType()->get_returnVals().front(); 155 106 } 156 } 157 return false; 158 } 159 160 Expression * FixIntrinsicResult::postmutate( ApplicationExpr * appExpr ) { 161 if ( isIntrinsicReference( appExpr ) ) { 162 // eliminate reference types from intrinsic applications - now they return lvalues 163 Type * result = appExpr->get_result(); 164 appExpr->set_result( result->stripReferences()->clone() ); 165 appExpr->get_result()->set_lvalue( true ); 166 if ( ! inIntrinsic ) { 167 // when not in an intrinsic function, add a cast to 168 // don't add cast when in an intrinsic function, since they already have the cast 169 Expression * ret = new CastExpr( appExpr, result ); 170 ret->set_env( appExpr->get_env() ); 171 appExpr->set_env( nullptr ); 172 return ret; 107 // fix expressions and return statements in this function 108 funcDecl->set_statements( funcDecl->get_statements()->acceptMutator( *this ) ); 109 retval = oldRetval; 110 } // if 111 return funcDecl; 112 } 113 114 Expression * Pass1::mutate( ApplicationExpr *appExpr ) { 115 appExpr->get_function()->acceptMutator( *this ); 116 mutateAll( appExpr->get_args(), *this ); 117 118 PointerType *pointer = safe_dynamic_cast< PointerType* >( appExpr->get_function()->get_result() ); 119 FunctionType *function = safe_dynamic_cast< FunctionType* >( pointer->get_base() ); 120 121 Type *funType = isLvalueRet( function ); 122 if ( funType && ! isIntrinsicApp( appExpr ) ) { 123 Expression *expr = appExpr; 124 Type *appType = appExpr->get_result(); 125 if ( isPolyType( funType ) && ! isPolyType( appType ) ) { 126 // make sure cast for polymorphic type is inside dereference 127 expr = new CastExpr( appExpr, new PointerType( Type::Qualifiers(), appType->clone() ) ); 173 128 } 174 delete result; 175 } 176 return appExpr; 177 } 178 179 void FixIntrinsicResult::premutate( FunctionDecl * funcDecl ) { 180 GuardValue( inIntrinsic ); 181 inIntrinsic = funcDecl->linkage == LinkageSpec::Intrinsic; 182 } 183 184 Expression * FixIntrinsicArgs::postmutate( ApplicationExpr * appExpr ) { 185 // intrinsic functions don't really take reference-typed parameters, so they require an implicit dereference on their arguments. 186 if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) { 187 FunctionType * ftype = GenPoly::getFunctionType( function->get_type() ); 188 assertf( ftype, "Function declaration does not have function type." ); 189 // can be of differing lengths only when function is variadic 190 assertf( ftype->get_parameters().size() == appExpr->get_args().size() || ftype->get_isVarArgs(), "ApplicationExpr args do not match formal parameter type." ); 191 192 193 unsigned int i = 0; 194 const unsigned int end = ftype->get_parameters().size(); 195 for ( auto p : unsafe_group_iterate( appExpr->get_args(), ftype->get_parameters() ) ) { 196 if (i == end) break; 197 Expression *& arg = std::get<0>( p ); 198 Type * formal = std::get<1>( p )->get_type(); 199 PRINT( 200 std::cerr << "pair<0>: " << arg << std::endl; 201 std::cerr << "pair<1>: " << formal << std::endl; 202 ) 203 if ( dynamic_cast<ReferenceType*>( formal ) ) { 204 if ( isIntrinsicReference( arg ) ) { // do not combine conditions, because that changes the meaning of the else if 205 if ( function->get_linkage() != LinkageSpec::Intrinsic ) { // intrinsic functions that turn pointers into references 206 // if argument is dereference or array subscript, the result isn't REALLY a reference, so it's not necessary to fix the argument 207 PRINT( 208 std::cerr << "===is intrinsic arg in non-intrinsic call - adding address" << std::endl; 209 ) 210 arg = new AddressExpr( arg ); 211 } 212 } else if ( function->get_linkage() == LinkageSpec::Intrinsic ) { 213 // std::cerr << "===adding deref to arg" << std::endl; 214 // if the parameter is a reference, add a dereference to the reference-typed argument. 215 Type * baseType = InitTweak::getPointerBase( arg->get_result() ); 216 assertf( baseType, "parameter is reference, arg must be pointer or reference: %s", toString( arg->get_result() ).c_str() ); 217 PointerType * ptrType = new PointerType( Type::Qualifiers(), baseType->clone() ); 218 delete arg->get_result(); 219 arg->set_result( ptrType ); 220 arg = mkDeref( arg ); 221 } 222 } 223 ++i; 224 } 225 } 226 return appExpr; 227 } 228 229 // idea: &&&E: get outer &, inner & 230 // at inner &, record depth D of reference type 231 // at outer &, add D derefs. 232 void AddrRef::premutate( Expression * ) { 233 GuardValue( current ); 234 GuardValue( first ); 235 current = false; 236 first = true; 237 } 238 239 void AddrRef::premutate( AddressExpr * ) { 240 GuardValue( current ); 241 GuardValue( first ); 242 current = first; 243 first = false; 244 if ( current ) { 245 GuardValue( refDepth ); 246 refDepth = 0; 247 } 248 } 249 250 Expression * AddrRef::postmutate( AddressExpr * addrExpr ) { 251 if ( refDepth == 0 ) { 252 if ( ! isIntrinsicReference( addrExpr->get_arg() ) ) { 253 // try to avoid ?[?] 254 refDepth = addrExpr->get_arg()->get_result()->referenceDepth(); 255 } 256 } 257 if ( current ) { 258 Expression * ret = addrExpr; 259 while ( refDepth ) { 260 ret = mkDeref( ret ); 261 refDepth--; 262 } 263 return ret; 264 } 265 return addrExpr; 266 } 267 268 Expression * ReferenceConversions::postmutate( AddressExpr * addrExpr ) { 269 // Inner expression may have been lvalue to reference conversion, which becomes an address expression. 270 // In this case, remove the outer address expression and return the argument. 271 // TODO: It's possible that this might catch too much and require a more sophisticated check. 272 return addrExpr; 273 } 274 275 Expression * ReferenceConversions::postmutate( CastExpr * castExpr ) { 276 // xxx - is it possible to convert directly between reference types with a different base? E.g., 277 // int x; 278 // (double&)x; 279 // At the moment, I am working off of the assumption that this is illegal, thus the cast becomes redundant 280 // after this pass, so trash the cast altogether. If that changes, care must be taken to insert the correct 281 // pointer casts in the right places. 282 283 // conversion to reference type 284 if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( castExpr->get_result() ) ) { 285 (void)refType; 286 if ( ReferenceType * otherRef = dynamic_cast< ReferenceType * >( castExpr->get_arg()->get_result() ) ) { 287 // nothing to do if casting from reference to reference. 288 (void)otherRef; 289 PRINT( std::cerr << "convert reference to reference -- nop" << std::endl; ) 290 if ( isIntrinsicReference( castExpr->get_arg() ) ) { 291 Expression * callExpr = castExpr->get_arg(); 292 PRINT( 293 std::cerr << "but arg is deref -- &" << std::endl; 294 std::cerr << callExpr << std::endl; 295 ) 296 callExpr = new AddressExpr( callExpr ); // this doesn't work properly for multiple casts 297 delete callExpr->get_result(); 298 callExpr->set_result( refType->clone() ); 299 // move environment out to new top-level 300 callExpr->set_env( castExpr->get_env() ); 301 castExpr->set_arg( nullptr ); 302 castExpr->set_env( nullptr ); 303 delete castExpr; 304 return callExpr; 305 } 306 int depth1 = refType->referenceDepth(); 307 int depth2 = otherRef->referenceDepth(); 308 int diff = depth1-depth2; 309 if ( diff == 0 ) { 310 assertf( depth1 == depth2, "non-intrinsic reference with cast of reference to reference not yet supported: %d %d %s", depth1, depth2, toString( castExpr ).c_str() ); 311 PRINT( std::cerr << castExpr << std::endl; ) 312 return castExpr; 313 } else if ( diff < 0 ) { 314 Expression * ret = castExpr->get_arg(); 315 for ( int i = 0; i < diff; ++i ) { 316 ret = mkDeref( ret ); 317 } 318 ret->set_env( castExpr->get_env() ); 319 delete ret->get_result(); 320 ret->set_result( castExpr->get_result() ); 321 castExpr->set_env( nullptr ); 322 castExpr->set_arg( nullptr ); 323 castExpr->set_result( nullptr ); 324 delete castExpr; 325 return ret; 326 } else if ( diff > 0 ) { 327 Expression * ret = castExpr->get_arg(); 328 for ( int i = 0; i < diff; ++i ) { 329 ret = new AddressExpr( ret ); 330 } 331 ret->set_env( castExpr->get_env() ); 332 delete ret->get_result(); 333 ret->set_result( castExpr->get_result() ); 334 castExpr->set_env( nullptr ); 335 castExpr->set_arg( nullptr ); 336 castExpr->set_result( nullptr ); 337 delete castExpr; 338 return ret; 339 } 340 341 assertf( depth1 == depth2, "non-intrinsic reference with cast of reference to reference not yet supported: %d %d %s", depth1, depth2, toString( castExpr ).c_str() ); 342 PRINT( std::cerr << castExpr << std::endl; ) 343 return castExpr; 344 } else if ( castExpr->get_arg()->get_result()->get_lvalue() ) { 345 // conversion from lvalue to reference 346 // xxx - keep cast, but turn into pointer cast?? 347 // xxx - memory 348 PRINT( 349 std::cerr << "convert lvalue to reference -- &" << std::endl; 350 std::cerr << castExpr->get_arg() << std::endl; 351 ) 352 AddressExpr * ret = new AddressExpr( castExpr->get_arg() ); 353 if ( refType->get_base()->get_qualifiers() != castExpr->get_arg()->get_result()->get_qualifiers() ) { 354 // must keep cast if cast-to type is different from the actual type 355 castExpr->set_arg( ret ); 356 return castExpr; 357 } 358 ret->set_env( castExpr->get_env() ); 359 delete ret->get_result(); 360 ret->set_result( castExpr->get_result() ); 361 castExpr->set_env( nullptr ); 362 castExpr->set_arg( nullptr ); 363 castExpr->set_result( nullptr ); 364 delete castExpr; 365 return ret; 129 UntypedExpr *deref = new UntypedExpr( new NameExpr( "*?" ) ); 130 deref->set_result( appType->clone() ); 131 appExpr->set_result( new PointerType( Type::Qualifiers(), appType ) ); 132 deref->get_args().push_back( expr ); 133 return deref; 134 } else { 135 return appExpr; 136 } // if 137 } 138 139 Statement * Pass1::mutate(ReturnStmt *retStmt) { 140 if ( retval && retStmt->get_expr() ) { 141 if ( retStmt->get_expr()->get_result()->get_lvalue() ) { 142 // ***** Code Removal ***** because casts may be stripped already 143 144 // strip casts because not allowed to take address of cast 145 // while ( CastExpr *castExpr = dynamic_cast< CastExpr* >( retStmt->get_expr() ) ) { 146 // retStmt->set_expr( castExpr->get_arg() ); 147 // retStmt->get_expr()->set_env( castExpr->get_env() ); 148 // castExpr->set_env( 0 ); 149 // castExpr->set_arg( 0 ); 150 // delete castExpr; 151 // } // while 152 retStmt->set_expr( new AddressExpr( retStmt->get_expr()->acceptMutator( *this ) ) ); 366 153 } else { 367 // rvalue to reference conversion -- introduce temporary 368 } 369 assertf( false, "Only conversions to reference from lvalue are currently supported: %s", toString( castExpr ).c_str() ); 370 } else if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( castExpr->get_arg()->get_result() ) ) { 371 (void)refType; 372 // conversion from reference to rvalue 373 PRINT( 374 std::cerr << "convert reference to rvalue -- *" << std::endl; 375 std::cerr << "was = " << castExpr << std::endl; 376 ) 377 Expression * ret = castExpr->get_arg(); 378 TypeSubstitution * env = castExpr->get_env(); 379 castExpr->set_env( nullptr ); 380 if ( ! isIntrinsicReference( ret ) ) { 381 // dereference if not already dereferenced 382 ret = mkDeref( ret ); 383 } 384 if ( ResolvExpr::typesCompatibleIgnoreQualifiers( castExpr->get_result(), castExpr->get_arg()->get_result()->stripReferences(), SymTab::Indexer() ) ) { 385 // can remove cast if types are compatible, changing expression type to value type 386 ret->set_result( castExpr->get_result()->clone() ); 387 castExpr->set_arg( nullptr ); 388 delete castExpr; 389 } else { 390 // must keep cast if types are different 391 castExpr->set_arg( ret ); 392 ret = castExpr; 393 } 394 ret->set_env( env ); 395 PRINT( std::cerr << "now: " << ret << std::endl; ) 396 return ret; 397 } 398 return castExpr; 399 } 400 401 Type * ReferenceTypeElimination::postmutate( ReferenceType * refType ) { 402 Type * base = refType->get_base(); 403 Type::Qualifiers qualifiers = refType->get_qualifiers(); 404 refType->set_base( nullptr ); 405 delete refType; 406 return new PointerType( qualifiers, base ); 154 throw SemanticError( "Attempt to return non-lvalue from an lvalue-qualified function" ); 155 } // if 156 } // if 157 return retStmt; 158 } 159 160 void Pass2::visit( FunctionType *funType ) { 161 std::string typeName; 162 if ( isLvalueRet( funType ) ) { 163 DeclarationWithType *retParm = funType->get_returnVals().front(); 164 165 // make a new parameter that is a pointer to the type of the old return value 166 retParm->set_type( new PointerType( Type::Qualifiers(), retParm->get_type() ) ); 167 } // if 168 169 Visitor::visit( funType ); 407 170 } 408 171 … … 412 175 Expression * arg1 = commaExpr->get_arg1()->clone(); 413 176 Expression * arg2 = commaExpr->get_arg2()->clone(); 414 Expression * ret = new CommaExpr( arg1, mkExpr( arg2 ) ->acceptMutator( *visitor ));177 Expression * ret = new CommaExpr( arg1, mkExpr( arg2 ) ); 415 178 ret->set_env( expr->get_env() ); 416 179 expr->set_env( nullptr ); 417 180 delete expr; 418 return ret ;181 return ret->acceptMutator( *this ); 419 182 } else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( arg ) ) { 420 183 Expression * arg1 = condExpr->get_arg1()->clone(); 421 184 Expression * arg2 = condExpr->get_arg2()->clone(); 422 185 Expression * arg3 = condExpr->get_arg3()->clone(); 423 ConditionalExpr * ret = new ConditionalExpr( arg1, mkExpr( arg2 ) ->acceptMutator( *visitor ), mkExpr( arg3 )->acceptMutator( *visitor) );186 ConditionalExpr * ret = new ConditionalExpr( arg1, mkExpr( arg2 ), mkExpr( arg3 ) ); 424 187 ret->set_env( expr->get_env() ); 425 188 expr->set_env( nullptr ); … … 434 197 unify( ret->get_arg2()->get_result(), ret->get_arg3()->get_result(), newEnv, needAssertions, haveAssertions, openVars, SymTab::Indexer(), commonType ); 435 198 ret->set_result( commonType ? commonType : ret->get_arg2()->get_result()->clone() ); 436 return ret ;199 return ret->acceptMutator( *this ); 437 200 } 438 201 return expr; 439 202 } 440 203 441 Expression * GeneralizedLvalue::postmutate( MemberExpr * memExpr ) { 204 Expression * GeneralizedLvalue::mutate( MemberExpr * memExpr ) { 205 Parent::mutate( memExpr ); 442 206 return applyTransformation( memExpr, memExpr->get_aggregate(), [=]( Expression * aggr ) { return new MemberExpr( memExpr->get_member(), aggr ); } ); 443 207 } 444 208 445 Expression * GeneralizedLvalue::postmutate( AddressExpr * addrExpr ) { 209 Expression * GeneralizedLvalue::mutate( AddressExpr * addrExpr ) { 210 addrExpr = safe_dynamic_cast< AddressExpr * >( Parent::mutate( addrExpr ) ); 446 211 return applyTransformation( addrExpr, addrExpr->get_arg(), []( Expression * arg ) { return new AddressExpr( arg ); } ); 447 }448 449 Expression * CollapseAddrDeref::postmutate( AddressExpr * addrExpr ) {450 Expression * arg = addrExpr->get_arg();451 if ( isIntrinsicReference( arg ) ) {452 std::string fname = InitTweak::getFunctionName( arg );453 if ( fname == "*?" ) {454 Expression *& arg0 = InitTweak::getCallArg( arg, 0 );455 Expression * ret = arg0;456 ret->set_env( addrExpr->get_env() );457 arg0 = nullptr;458 addrExpr->set_env( nullptr );459 delete addrExpr;460 return ret;461 }462 }463 return addrExpr;464 }465 466 Expression * CollapseAddrDeref::postmutate( ApplicationExpr * appExpr ) {467 if ( isIntrinsicReference( appExpr ) ) {468 std::string fname = InitTweak::getFunctionName( appExpr );469 if ( fname == "*?" ) {470 Expression * arg = InitTweak::getCallArg( appExpr, 0 );471 // xxx - this isn't right, because it can remove casts that should be there...472 // while ( CastExpr * castExpr = dynamic_cast< CastExpr * >( arg ) ) {473 // arg = castExpr->get_arg();474 // }475 if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( arg ) ) {476 Expression * ret = addrExpr->get_arg();477 ret->set_env( appExpr->get_env() );478 addrExpr->set_arg( nullptr );479 appExpr->set_env( nullptr );480 delete appExpr;481 return ret;482 }483 }484 }485 return appExpr;486 212 } 487 213 } // namespace
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