source: src/GenPoly/Lvalue.cc@ 8d70648

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 8d70648 was 2bfc6b2, checked in by Rob Schluntz <rschlunt@…>, 7 years ago

Refactor FindSpecialDeclarations and associated special declarations
  • Property mode set to 100644
File size: 23.2 KB
Line 
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// Lvalue.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Mon May 18 07:44:20 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Fri Mar 17 09:11:18 2017
13// Update Count : 5
14//
15
16#include <cassert> // for strict_dynamic_cast
17#include <string> // for string
18
19#include "Common/PassVisitor.h"
20#include "GenPoly.h" // for isPolyType
21#include "Lvalue.h"
22
23#include "InitTweak/InitTweak.h"
24#include "Parser/LinkageSpec.h" // for Spec, isBuiltin, Intrinsic
25#include "ResolvExpr/TypeEnvironment.h" // for AssertionSet, OpenVarSet
26#include "ResolvExpr/Unify.h" // for unify
27#include "ResolvExpr/typeops.h"
28#include "SymTab/Indexer.h" // for Indexer
29#include "SynTree/Declaration.h" // for Declaration, FunctionDecl
30#include "SynTree/Expression.h" // for Expression, ConditionalExpr
31#include "SynTree/Mutator.h" // for mutateAll, Mutator
32#include "SynTree/Statement.h" // for ReturnStmt, Statement (ptr o...
33#include "SynTree/Type.h" // for PointerType, Type, FunctionType
34#include "SynTree/Visitor.h" // for Visitor, acceptAll
35#include "Validate/FindSpecialDecls.h" // for dereferenceOperator
36
37#if 0
38#define PRINT(x) x
39#else
40#define PRINT(x)
41#endif
42
43namespace GenPoly {
44 namespace {
45 // TODO: fold this into the general createDeref function??
46 Expression * mkDeref( Expression * arg ) {
47 if ( Validate::dereferenceOperator ) {
48 // note: reference depth can be arbitrarily deep here, so peel off the outermost pointer/reference, not just pointer because they are effecitvely equivalent in this pass
49 VariableExpr * deref = new VariableExpr( Validate::dereferenceOperator );
50 deref->result = new PointerType( Type::Qualifiers(), deref->result );
51 Type * base = InitTweak::getPointerBase( arg->result );
52 assertf( base, "expected pointer type in dereference (type was %s)", toString( arg->result ).c_str() );
53 ApplicationExpr * ret = new ApplicationExpr( deref, { arg } );
54 delete ret->result;
55 ret->result = base->clone();
56 ret->result->set_lvalue( true );
57 return ret;
58 } else {
59 return UntypedExpr::createDeref( arg );
60 }
61 }
62
63 struct ReferenceConversions final : public WithStmtsToAdd {
64 Expression * postmutate( CastExpr * castExpr );
65 Expression * postmutate( AddressExpr * addrExpr );
66 };
67
68 /// Intrinsic functions that take reference parameters don't REALLY take reference parameters -- their reference arguments must always be implicitly dereferenced.
69 struct FixIntrinsicArgs final {
70 Expression * postmutate( ApplicationExpr * appExpr );
71 };
72
73 struct FixIntrinsicResult final : public WithGuards {
74 Expression * postmutate( ApplicationExpr * appExpr );
75 void premutate( FunctionDecl * funcDecl );
76 bool inIntrinsic = false;
77 };
78
79 /// Replace reference types with pointer types
80 struct ReferenceTypeElimination final {
81 Type * postmutate( ReferenceType * refType );
82 };
83
84 /// GCC-like Generalized Lvalues (which have since been removed from GCC)
85 /// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues
86 /// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c)
87 struct GeneralizedLvalue final : public WithVisitorRef<GeneralizedLvalue> {
88 Expression * postmutate( AddressExpr * addressExpr );
89 Expression * postmutate( MemberExpr * memExpr );
90
91 template<typename Func>
92 Expression * applyTransformation( Expression * expr, Expression * arg, Func mkExpr );
93 };
94
95 /// Removes redundant &*/*& pattern that this pass can generate
96 struct CollapseAddrDeref final {
97 Expression * postmutate( AddressExpr * addressExpr );
98 Expression * postmutate( ApplicationExpr * appExpr );
99 };
100
101 struct AddrRef final : public WithGuards, public WithVisitorRef<AddrRef>, public WithShortCircuiting {
102 void premutate( AddressExpr * addrExpr );
103 Expression * postmutate( AddressExpr * addrExpr );
104 void premutate( Expression * expr );
105 void premutate( ApplicationExpr * appExpr );
106 void premutate( SingleInit * init );
107
108 void handleNonAddr( Expression * );
109
110 bool first = true;
111 bool current = false;
112 int refDepth = 0;
113 bool addCast = false;
114 };
115 } // namespace
116
117 static bool referencesEliminated = false;
118 // used by UntypedExpr::createDeref to determine whether result type of dereference should be ReferenceType or value type.
119 bool referencesPermissable() {
120 return ! referencesEliminated;
121 }
122
123 void convertLvalue( std::list< Declaration* > & translationUnit ) {
124 PassVisitor<ReferenceConversions> refCvt;
125 PassVisitor<ReferenceTypeElimination> elim;
126 PassVisitor<GeneralizedLvalue> genLval;
127 PassVisitor<FixIntrinsicArgs> fixer;
128 PassVisitor<CollapseAddrDeref> collapser;
129 PassVisitor<AddrRef> addrRef;
130 PassVisitor<FixIntrinsicResult> intrinsicResults;
131 mutateAll( translationUnit, intrinsicResults );
132 mutateAll( translationUnit, addrRef );
133 mutateAll( translationUnit, refCvt );
134 mutateAll( translationUnit, fixer );
135 mutateAll( translationUnit, collapser );
136 mutateAll( translationUnit, genLval );
137 mutateAll( translationUnit, elim ); // last because other passes need reference types to work
138
139 // from this point forward, no other pass should create reference types.
140 referencesEliminated = true;
141 }
142
143 Expression * generalizedLvalue( Expression * expr ) {
144 PassVisitor<GeneralizedLvalue> genLval;
145 return expr->acceptMutator( genLval );
146 }
147
148 namespace {
149 // true for intrinsic function calls that return an lvalue in C
150 bool isIntrinsicReference( Expression * expr ) {
151 // known intrinsic-reference prelude functions
152 static std::set<std::string> lvalueFunctions = { "*?", "?[?]" };
153 if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) {
154 std::string fname = InitTweak::getFunctionName( untyped );
155 return lvalueFunctions.count(fname);
156 } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
157 if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) {
158 return func->linkage == LinkageSpec::Intrinsic && lvalueFunctions.count(func->name);
159 }
160 }
161 return false;
162 }
163
164 Expression * FixIntrinsicResult::postmutate( ApplicationExpr * appExpr ) {
165 if ( isIntrinsicReference( appExpr ) ) {
166 // eliminate reference types from intrinsic applications - now they return lvalues
167 ReferenceType * result = strict_dynamic_cast< ReferenceType * >( appExpr->result );
168 appExpr->result = result->base->clone();
169 appExpr->result->set_lvalue( true );
170 if ( ! inIntrinsic ) {
171 // when not in an intrinsic function, add a cast to
172 // don't add cast when in an intrinsic function, since they already have the cast
173 Expression * ret = new CastExpr( appExpr, result );
174 std::swap( ret->env, appExpr->env );
175 return ret;
176 }
177 delete result;
178 }
179 return appExpr;
180 }
181
182 void FixIntrinsicResult::premutate( FunctionDecl * funcDecl ) {
183 GuardValue( inIntrinsic );
184 inIntrinsic = funcDecl->linkage == LinkageSpec::Intrinsic;
185 }
186
187 Expression * FixIntrinsicArgs::postmutate( ApplicationExpr * appExpr ) {
188 // intrinsic functions don't really take reference-typed parameters, so they require an implicit dereference on their arguments.
189 if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
190 FunctionType * ftype = GenPoly::getFunctionType( function->get_type() );
191 assertf( ftype, "Function declaration does not have function type." );
192 // can be of differing lengths only when function is variadic
193 assertf( ftype->parameters.size() == appExpr->args.size() || ftype->isVarArgs, "ApplicationExpr args do not match formal parameter type." );
194
195
196 unsigned int i = 0;
197 const unsigned int end = ftype->parameters.size();
198 for ( auto p : unsafe_group_iterate( appExpr->args, ftype->parameters ) ) {
199 if (i == end) break;
200 Expression *& arg = std::get<0>( p );
201 Type * formal = std::get<1>( p )->get_type();
202 PRINT(
203 std::cerr << "pair<0>: " << arg << std::endl;
204 std::cerr << " -- " << arg->result << std::endl;
205 std::cerr << "pair<1>: " << formal << std::endl;
206 )
207 if ( dynamic_cast<ReferenceType*>( formal ) ) {
208 PRINT(
209 std::cerr << "===formal is reference" << std::endl;
210 )
211 // TODO: it's likely that the second condition should be ... && ! isIntrinsicReference( arg ), but this requires investigation.
212
213 if ( function->linkage != LinkageSpec::Intrinsic && isIntrinsicReference( arg ) ) {
214 // needed for definition of prelude functions, etc.
215 // if argument is dereference or array subscript, the result isn't REALLY a reference, but non-intrinsic functions expect a reference: take address
216
217 // NOTE: previously, this condition fixed
218 // void f(int *&);
219 // int & x = ...;
220 // f(&x);
221 // But now this is taken care of by a reference cast added by AddrRef. Need to find a new
222 // example or remove this branch.
223
224 PRINT(
225 std::cerr << "===is intrinsic arg in non-intrinsic call - adding address" << std::endl;
226 )
227 arg = new AddressExpr( arg );
228 // } else if ( function->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getPointerBase( arg->result ) ) {
229 } else if ( function->linkage == LinkageSpec::Intrinsic && arg->result->referenceDepth() != 0 ) {
230 // argument is a 'real' reference, but function expects a C lvalue: add a dereference to the reference-typed argument
231 PRINT(
232 std::cerr << "===is non-intrinsic arg in intrinsic call - adding deref to arg" << std::endl;
233 )
234 Type * baseType = InitTweak::getPointerBase( arg->result );
235 assertf( baseType, "parameter is reference, arg must be pointer or reference: %s", toString( arg->result ).c_str() );
236 PointerType * ptrType = new PointerType( Type::Qualifiers(), baseType->clone() );
237 delete arg->result;
238 arg->result = ptrType;
239 arg = mkDeref( arg );
240 // assertf( arg->result->referenceDepth() == 0, "Reference types should have been eliminated from intrinsic function calls, but weren't: %s", toCString( arg->result ) );
241 }
242 }
243 ++i;
244 }
245 }
246 return appExpr;
247 }
248
249 // idea: &&&E: get outer &, inner &
250 // at inner &, record depth D of reference type of argument of &
251 // at outer &, add D derefs.
252 void AddrRef::handleNonAddr( Expression * ) {
253 // non-address-of: reset status variables:
254 // * current expr is NOT the first address-of expr in an address-of chain
255 // * next seen address-of expr IS the first in the chain.
256 GuardValue( current );
257 GuardValue( first );
258 current = false;
259 first = true;
260 }
261
262 void AddrRef::premutate( Expression * expr ) {
263 handleNonAddr( expr );
264 GuardValue( addCast );
265 addCast = false;
266 }
267
268 void AddrRef::premutate( AddressExpr * ) {
269 GuardValue( current );
270 GuardValue( first );
271 current = first; // is this the first address-of in the chain?
272 first = false; // from here out, no longer possible for next address-of to be first in chain
273 if ( current ) { // this is the outermost address-of in a chain
274 GuardValue( refDepth );
275 refDepth = 0; // set depth to 0 so that postmutate can find the innermost address-of easily
276 }
277 }
278
279 Expression * AddrRef::postmutate( AddressExpr * addrExpr ) {
280 PRINT( std::cerr << "addr ref at " << addrExpr << std::endl; )
281 if ( refDepth == 0 ) {
282 PRINT( std::cerr << "depth 0, get new depth..." << std::endl; )
283 // this is the innermost address-of in a chain, record depth D
284 if ( ! isIntrinsicReference( addrExpr->arg ) ) {
285 // try to avoid ?[?]
286 // xxx - is this condition still necessary? intrinsicReferences should have a cast around them at this point, so I don't think this condition ever fires.
287 refDepth = addrExpr->arg->result->referenceDepth();
288 PRINT( std::cerr << "arg not intrinsic reference, new depth is: " << refDepth << std::endl; )
289 } else {
290 assertf( false, "AddrRef : address-of should not have intrinsic reference argument: %s", toCString( addrExpr->arg ) );
291 }
292 }
293 if ( current ) { // this is the outermost address-of in a chain
294 PRINT( std::cerr << "current, depth is: " << refDepth << std::endl; )
295 Expression * ret = addrExpr;
296 while ( refDepth ) {
297 // add one dereference for each
298 ret = mkDeref( ret );
299 refDepth--;
300 }
301
302 // if addrExpr depth is 0, then the result is a pointer because the arg was depth 1 and not lvalue.
303 // This means the dereference result is not a reference, is lvalue, and one less pointer depth than
304 // the addrExpr. Thus the cast is meaningless.
305 // TODO: One thing to double check is whether it is possible for the types to differ outside of the single
306 // pointer level (i.e. can the base type of addrExpr differ from the type of addrExpr-arg?).
307 // If so then the cast might need to be added, conditional on a more sophisticated check.
308 if ( addCast && addrExpr->result->referenceDepth() != 0 ) {
309 PRINT( std::cerr << "adding cast to " << addrExpr->result << std::endl; )
310 return new CastExpr( ret, addrExpr->result->clone() );
311 }
312 return ret;
313 }
314 PRINT( std::cerr << "not current..." << std::endl; )
315 return addrExpr;
316 }
317
318 void AddrRef::premutate( ApplicationExpr * appExpr ) {
319 visit_children = false;
320 GuardValue( addCast );
321 handleNonAddr( appExpr );
322 for ( Expression *& arg : appExpr->args ) {
323 // each argument with address-of requires a cast
324 addCast = true;
325 arg = arg->acceptMutator( *visitor );
326 }
327 }
328
329 void AddrRef::premutate( SingleInit * ) {
330 GuardValue( addCast );
331 // each initialization context with address-of requires a cast
332 addCast = true;
333 }
334
335
336 Expression * ReferenceConversions::postmutate( AddressExpr * addrExpr ) {
337 // Inner expression may have been lvalue to reference conversion, which becomes an address expression.
338 // In this case, remove the outer address expression and return the argument.
339 // TODO: It's possible that this might catch too much and require a more sophisticated check.
340 return addrExpr;
341 }
342
343 Expression * ReferenceConversions::postmutate( CastExpr * castExpr ) {
344 // xxx - is it possible to convert directly between reference types with a different base? E.g.,
345 // int x;
346 // (double&)x;
347 // At the moment, I am working off of the assumption that this is illegal, thus the cast becomes redundant
348 // after this pass, so trash the cast altogether. If that changes, care must be taken to insert the correct
349 // pointer casts in the right places.
350
351 // Note: reference depth difference is the determining factor in what code is run, rather than whether something is
352 // reference type or not, since conversion still needs to occur when both types are references that differ in depth.
353
354 Type * destType = castExpr->result;
355 Type * srcType = castExpr->arg->result;
356 assertf( destType, "Cast to no type in: %s", toCString( castExpr ) );
357 assertf( srcType, "Cast from no type in: %s", toCString( castExpr ) );
358 int depth1 = destType->referenceDepth();
359 int depth2 = srcType->referenceDepth();
360 int diff = depth1 - depth2;
361
362 if ( diff > 0 && ! srcType->get_lvalue() ) {
363 // rvalue to reference conversion -- introduce temporary
364 // know that reference depth of cast argument is 0, need to introduce n temporaries for reference depth of n, e.g.
365 // (int &&&)3;
366 // becomes
367 // int __ref_tmp_0 = 3;
368 // int & __ref_tmp_1 = _&_ref_tmp_0;
369 // int && __ref_tmp_2 = &__ref_tmp_1;
370 // &__ref_tmp_2;
371 // the last & comes from the remaining reference conversion code
372 SemanticWarning( castExpr->arg->location, Warning::RvalueToReferenceConversion, toCString( castExpr->arg ) );
373
374 static UniqueName tempNamer( "__ref_tmp_" );
375 ObjectDecl * temp = ObjectDecl::newObject( tempNamer.newName(), castExpr->arg->result->clone(), new SingleInit( castExpr->arg ) );
376 PRINT( std::cerr << "made temp: " << temp << std::endl; )
377 stmtsToAddBefore.push_back( new DeclStmt( temp ) );
378 for ( int i = 0; i < depth1-1; i++ ) { // xxx - maybe this should be diff-1? check how this works with reference type for srcType
379 ObjectDecl * newTemp = ObjectDecl::newObject( tempNamer.newName(), new ReferenceType( Type::Qualifiers(), temp->type->clone() ), new SingleInit( new AddressExpr( new VariableExpr( temp ) ) ) );
380 PRINT( std::cerr << "made temp" << i << ": " << newTemp << std::endl; )
381 stmtsToAddBefore.push_back( new DeclStmt( newTemp ) );
382 temp = newTemp;
383 }
384 // update diff so that remaining code works out correctly
385 castExpr->arg = new VariableExpr( temp );
386 PRINT( std::cerr << "update cast to: " << castExpr << std::endl; )
387 srcType = castExpr->arg->result;
388 depth2 = srcType->referenceDepth();
389 diff = depth1 - depth2;
390 assert( diff == 1 );
391 }
392
393 // handle conversion between different depths
394 PRINT (
395 if ( depth1 || depth2 ) {
396 std::cerr << "destType: " << destType << " / srcType: " << srcType << std::endl;
397 std::cerr << "depth: " << depth1 << " / " << depth2 << std::endl;
398 }
399 )
400 if ( diff > 0 ) {
401 // conversion to type with more depth (e.g. int & -> int &&): add address-of for each level of difference
402 Expression * ret = castExpr->arg;
403 for ( int i = 0; i < diff; ++i ) {
404 ret = new AddressExpr( ret );
405 }
406 if ( srcType->get_lvalue() && ! ResolvExpr::typesCompatible( srcType, strict_dynamic_cast<ReferenceType *>( destType )->base, SymTab::Indexer() ) ) {
407 // must keep cast if cast-to type is different from the actual type
408 castExpr->arg = ret;
409 return castExpr;
410 }
411 ret->env = castExpr->env;
412 delete ret->result;
413 ret->result = castExpr->result;
414 castExpr->env = nullptr;
415 castExpr->arg = nullptr;
416 castExpr->result = nullptr;
417 delete castExpr;
418 return ret;
419 } else if ( diff < 0 ) {
420 // conversion to type with less depth (e.g. int && -> int &): add dereferences for each level of difference
421 diff = -diff; // care only about magnitude now
422 Expression * ret = castExpr->arg;
423 for ( int i = 0; i < diff; ++i ) {
424 ret = mkDeref( ret );
425 // xxx - try removing one reference here? actually, looks like mkDeref already does this, so more closely look at the types generated.
426 }
427 if ( ! ResolvExpr::typesCompatibleIgnoreQualifiers( destType->stripReferences(), srcType->stripReferences(), SymTab::Indexer() ) ) {
428 // must keep cast if types are different
429 castExpr->arg = ret;
430 return castExpr;
431 }
432 ret->env = castExpr->env;
433 delete ret->result;
434 ret->result = castExpr->result;
435 ret->result->set_lvalue( true ); // ensure result is lvalue
436 castExpr->env = nullptr;
437 castExpr->arg = nullptr;
438 castExpr->result = nullptr;
439 delete castExpr;
440 return ret;
441 } else {
442 assert( diff == 0 );
443 // conversion between references of the same depth
444 if ( ResolvExpr::typesCompatible( castExpr->result, castExpr->arg->result, SymTab::Indexer() ) && castExpr->isGenerated ) {
445 // Remove useless generated casts
446 PRINT(
447 std::cerr << "types are compatible, removing cast: " << castExpr << std::endl;
448 std::cerr << "-- " << castExpr->result << std::endl;
449 std::cerr << "-- " << castExpr->arg->result << std::endl;
450 )
451 Expression * ret = castExpr->arg;
452 castExpr->arg = nullptr;
453 std::swap( castExpr->env, ret->env );
454 delete castExpr;
455 return ret;
456 }
457 return castExpr;
458 }
459 }
460
461 Type * ReferenceTypeElimination::postmutate( ReferenceType * refType ) {
462 Type * base = refType->base;
463 Type::Qualifiers qualifiers = refType->get_qualifiers();
464 refType->base = nullptr;
465 delete refType;
466 return new PointerType( qualifiers, base );
467 }
468
469 template<typename Func>
470 Expression * GeneralizedLvalue::applyTransformation( Expression * expr, Expression * arg, Func mkExpr ) {
471 if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( arg ) ) {
472 Expression * arg1 = commaExpr->arg1->clone();
473 Expression * arg2 = commaExpr->arg2->clone();
474 Expression * ret = new CommaExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ) );
475 ret->env = expr->env;
476 expr->env = nullptr;
477 delete expr;
478 return ret;
479 } else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( arg ) ) {
480 Expression * arg1 = condExpr->arg1->clone();
481 Expression * arg2 = condExpr->arg2->clone();
482 Expression * arg3 = condExpr->arg3->clone();
483 ConditionalExpr * ret = new ConditionalExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ), mkExpr( arg3 )->acceptMutator( *visitor ) );
484 ret->env = expr->env;
485 expr->env = nullptr;
486 delete expr;
487
488 // conditional expr type may not be either of the argument types, need to unify
489 using namespace ResolvExpr;
490 Type* commonType = nullptr;
491 TypeEnvironment newEnv;
492 AssertionSet needAssertions, haveAssertions;
493 OpenVarSet openVars;
494 unify( ret->arg2->result, ret->arg3->result, newEnv, needAssertions, haveAssertions, openVars, SymTab::Indexer(), commonType );
495 ret->result = commonType ? commonType : ret->arg2->result->clone();
496 return ret;
497 }
498 return expr;
499 }
500
501 Expression * GeneralizedLvalue::postmutate( MemberExpr * memExpr ) {
502 return applyTransformation( memExpr, memExpr->aggregate, [=]( Expression * aggr ) { return new MemberExpr( memExpr->member, aggr ); } );
503 }
504
505 Expression * GeneralizedLvalue::postmutate( AddressExpr * addrExpr ) {
506 return applyTransformation( addrExpr, addrExpr->arg, []( Expression * arg ) { return new AddressExpr( arg ); } );
507 }
508
509 Expression * CollapseAddrDeref::postmutate( AddressExpr * addrExpr ) {
510 Expression * arg = addrExpr->arg;
511 if ( isIntrinsicReference( arg ) ) {
512 std::string fname = InitTweak::getFunctionName( arg );
513 if ( fname == "*?" ) {
514 Expression *& arg0 = InitTweak::getCallArg( arg, 0 );
515 Expression * ret = arg0;
516 ret->set_env( addrExpr->env );
517 arg0 = nullptr;
518 addrExpr->env = nullptr;
519 delete addrExpr;
520 return ret;
521 }
522 } else if ( CastExpr * castExpr = dynamic_cast< CastExpr * > ( arg ) ) {
523 // need to move cast to pointer type out a level since address of pointer
524 // is not valid C code (can be introduced in prior passes, e.g., InstantiateGeneric)
525 if ( InitTweak::getPointerBase( castExpr->result ) ) {
526 addrExpr->arg = castExpr->arg;
527 castExpr->arg = addrExpr;
528 castExpr->result = new PointerType( Type::Qualifiers(), castExpr->result );
529 return castExpr;
530 }
531 }
532 return addrExpr;
533 }
534
535 Expression * CollapseAddrDeref::postmutate( ApplicationExpr * appExpr ) {
536 if ( isIntrinsicReference( appExpr ) ) {
537 std::string fname = InitTweak::getFunctionName( appExpr );
538 if ( fname == "*?" ) {
539 Expression * arg = InitTweak::getCallArg( appExpr, 0 );
540 // xxx - this isn't right, because it can remove casts that should be there...
541 // while ( CastExpr * castExpr = dynamic_cast< CastExpr * >( arg ) ) {
542 // arg = castExpr->get_arg();
543 // }
544 if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( arg ) ) {
545 Expression * ret = addrExpr->arg;
546 ret->env = appExpr->env;
547 addrExpr->arg = nullptr;
548 appExpr->env = nullptr;
549 delete appExpr;
550 return ret;
551 }
552 }
553 }
554 return appExpr;
555 }
556 } // namespace
557} // namespace GenPoly
558
559// Local Variables: //
560// tab-width: 4 //
561// mode: c++ //
562// compile-command: "make install" //
563// End: //
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