source: src/GenPoly/Lvalue.cc@ d28a03e

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors deferred_resn demangler enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr new-env no_list persistent-indexer pthread-emulation qualifiedEnum with_gc
Last change on this file since d28a03e was 57acae0, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

Update condition for adding cast to address-of-reference, update debug prints
  • Property mode set to 100644
File size: 23.1 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 "Parser/LinkageSpec.h" // for Spec, isBuiltin, Intrinsic
24#include "ResolvExpr/TypeEnvironment.h" // for AssertionSet, OpenVarSet
25#include "ResolvExpr/Unify.h" // for unify
26#include "ResolvExpr/typeops.h"
27#include "SymTab/Autogen.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
36#if 0
37#define PRINT(x) x
38#else
39#define PRINT(x)
40#endif
41
42namespace GenPoly {
43 namespace {
44 // TODO: fold this into the general createDeref function??
45 Expression * mkDeref( Expression * arg ) {
46 if ( SymTab::dereferenceOperator ) {
47 // 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
48 VariableExpr * deref = new VariableExpr( SymTab::dereferenceOperator );
49 deref->result = new PointerType( Type::Qualifiers(), deref->result );
50 Type * base = InitTweak::getPointerBase( arg->result );
51 assertf( base, "expected pointer type in dereference (type was %s)", toString( arg->result ).c_str() );
52 ApplicationExpr * ret = new ApplicationExpr( deref, { arg } );
53 delete ret->result;
54 ret->result = base->clone();
55 ret->result->set_lvalue( true );
56 return ret;
57 } else {
58 return UntypedExpr::createDeref( arg );
59 }
60 }
61
62 struct ReferenceConversions final : public WithStmtsToAdd {
63 Expression * postmutate( CastExpr * castExpr );
64 Expression * postmutate( AddressExpr * addrExpr );
65 };
66
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 );
81 };
82
83 /// GCC-like Generalized Lvalues (which have since been removed from GCC)
84 /// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues
85 /// 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 );
89
90 template<typename Func>
91 Expression * applyTransformation( Expression * expr, Expression * arg, Func mkExpr );
92 };
93
94 /// Removes redundant &*/*& pattern that this pass can generate
95 struct CollapseAddrDeref final {
96 Expression * postmutate( AddressExpr * addressExpr );
97 Expression * postmutate( ApplicationExpr * appExpr );
98 };
99
100 struct AddrRef final : public WithGuards, public WithVisitorRef<AddrRef>, public WithShortCircuiting {
101 void premutate( AddressExpr * addrExpr );
102 Expression * postmutate( AddressExpr * addrExpr );
103 void premutate( Expression * expr );
104 void premutate( ApplicationExpr * appExpr );
105 void premutate( SingleInit * init );
106
107 void handleNonAddr( Expression * );
108
109 bool first = true;
110 bool current = false;
111 int refDepth = 0;
112 bool addCast = false;
113 };
114 } // namespace
115
116 static bool referencesEliminated = false;
117 // used by UntypedExpr::createDeref to determine whether result type of dereference should be ReferenceType or value type.
118 bool referencesPermissable() {
119 return ! referencesEliminated;
120 }
121
122 void convertLvalue( std::list< Declaration* > & translationUnit ) {
123 PassVisitor<ReferenceConversions> refCvt;
124 PassVisitor<ReferenceTypeElimination> elim;
125 PassVisitor<GeneralizedLvalue> genLval;
126 PassVisitor<FixIntrinsicArgs> fixer;
127 PassVisitor<CollapseAddrDeref> collapser;
128 PassVisitor<AddrRef> addrRef;
129 PassVisitor<FixIntrinsicResult> intrinsicResults;
130 mutateAll( translationUnit, intrinsicResults );
131 mutateAll( translationUnit, addrRef );
132 mutateAll( translationUnit, refCvt );
133 mutateAll( translationUnit, fixer );
134 mutateAll( translationUnit, collapser );
135 mutateAll( translationUnit, genLval );
136 mutateAll( translationUnit, elim ); // last because other passes need reference types to work
137
138 // from this point forward, no other pass should create reference types.
139 referencesEliminated = true;
140 }
141
142 Expression * generalizedLvalue( Expression * expr ) {
143 PassVisitor<GeneralizedLvalue> genLval;
144 return expr->acceptMutator( genLval );
145 }
146
147 namespace {
148 // true for intrinsic function calls that return a reference
149 bool isIntrinsicReference( Expression * expr ) {
150 if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) {
151 std::string fname = InitTweak::getFunctionName( untyped );
152 // known intrinsic-reference prelude functions
153 return fname == "*?" || fname == "?[?]";
154 } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
155 if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) {
156 // use type of return variable rather than expr result type, since it may have been changed to a pointer type
157 FunctionType * ftype = GenPoly::getFunctionType( func->get_type() );
158 Type * ret = ftype->returnVals.empty() ? nullptr : ftype->returnVals.front()->get_type();
159 return func->linkage == LinkageSpec::Intrinsic && dynamic_cast<ReferenceType *>( ret );
160 }
161 }
162 return false;
163 }
164
165 Expression * FixIntrinsicResult::postmutate( ApplicationExpr * appExpr ) {
166 if ( isIntrinsicReference( appExpr ) ) {
167 // eliminate reference types from intrinsic applications - now they return lvalues
168 Type * result = appExpr->result;
169 appExpr->result = result->stripReferences()->clone();
170 appExpr->result->set_lvalue( true );
171 if ( ! inIntrinsic ) {
172 // when not in an intrinsic function, add a cast to
173 // don't add cast when in an intrinsic function, since they already have the cast
174 Expression * ret = new CastExpr( appExpr, result );
175 std::swap( ret->env, appExpr->env );
176 return ret;
177 }
178 delete result;
179 }
180 return appExpr;
181 }
182
183 void FixIntrinsicResult::premutate( FunctionDecl * funcDecl ) {
184 GuardValue( inIntrinsic );
185 inIntrinsic = funcDecl->linkage == LinkageSpec::Intrinsic;
186 }
187
188 Expression * FixIntrinsicArgs::postmutate( ApplicationExpr * appExpr ) {
189 // intrinsic functions don't really take reference-typed parameters, so they require an implicit dereference on their arguments.
190 if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
191 FunctionType * ftype = GenPoly::getFunctionType( function->get_type() );
192 assertf( ftype, "Function declaration does not have function type." );
193 // can be of differing lengths only when function is variadic
194 assertf( ftype->parameters.size() == appExpr->args.size() || ftype->isVarArgs, "ApplicationExpr args do not match formal parameter type." );
195
196
197 unsigned int i = 0;
198 const unsigned int end = ftype->parameters.size();
199 for ( auto p : unsafe_group_iterate( appExpr->args, ftype->parameters ) ) {
200 if (i == end) break;
201 Expression *& arg = std::get<0>( p );
202 Type * formal = std::get<1>( p )->get_type();
203 PRINT(
204 std::cerr << "pair<0>: " << arg << std::endl;
205 std::cerr << " -- " << arg->result << std::endl;
206 std::cerr << "pair<1>: " << formal << std::endl;
207 )
208 if ( dynamic_cast<ReferenceType*>( formal ) ) {
209 PRINT(
210 std::cerr << "===formal is reference" << std::endl;
211 )
212 // TODO: it's likely that the second condition should be ... && ! isIntrinsicReference( arg ), but this requires investigation.
213
214 if ( function->get_linkage() != LinkageSpec::Intrinsic && isIntrinsicReference( arg ) ) {
215 // needed for definition of prelude functions, etc.
216 // if argument is dereference or array subscript, the result isn't REALLY a reference, but non-intrinsic functions expect a reference: take address
217
218 // NOTE: previously, this condition fixed
219 // void f(int *&);
220 // int & x = ...;
221 // f(&x);
222 // But now this is taken care of by a reference cast added by AddrRef. Need to find a new
223 // example or remove this branch.
224
225 PRINT(
226 std::cerr << "===is intrinsic arg in non-intrinsic call - adding address" << std::endl;
227 )
228 arg = new AddressExpr( arg );
229 // } else if ( function->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getPointerBase( arg->result ) ) {
230 } else if ( function->get_linkage() == LinkageSpec::Intrinsic && arg->result->referenceDepth() != 0 ) {
231 // argument is a 'real' reference, but function expects a C lvalue: add a dereference to the reference-typed argument
232 PRINT(
233 std::cerr << "===is non-intrinsic arg in intrinsic call - adding deref to arg" << std::endl;
234 )
235 Type * baseType = InitTweak::getPointerBase( arg->result );
236 assertf( baseType, "parameter is reference, arg must be pointer or reference: %s", toString( arg->result ).c_str() );
237 PointerType * ptrType = new PointerType( Type::Qualifiers(), baseType->clone() );
238 delete arg->result;
239 arg->result = ptrType;
240 arg = mkDeref( arg );
241 // assertf( arg->result->referenceDepth() == 0, "Reference types should have been eliminated from intrinsic function calls, but weren't: %s", toCString( arg->result ) );
242 }
243 }
244 ++i;
245 }
246 }
247 return appExpr;
248 }
249
250 // idea: &&&E: get outer &, inner &
251 // at inner &, record depth D of reference type of argument of &
252 // at outer &, add D derefs.
253 void AddrRef::handleNonAddr( Expression * ) {
254 // non-address-of: reset status variables:
255 // * current expr is NOT the first address-of expr in an address-of chain
256 // * next seen address-of expr IS the first in the chain.
257 GuardValue( current );
258 GuardValue( first );
259 current = false;
260 first = true;
261 }
262
263 void AddrRef::premutate( Expression * expr ) {
264 handleNonAddr( expr );
265 GuardValue( addCast );
266 addCast = false;
267 }
268
269 void AddrRef::premutate( AddressExpr * ) {
270 GuardValue( current );
271 GuardValue( first );
272 current = first; // is this the first address-of in the chain?
273 first = false; // from here out, no longer possible for next address-of to be first in chain
274 if ( current ) { // this is the outermost address-of in a chain
275 GuardValue( refDepth );
276 refDepth = 0; // set depth to 0 so that postmutate can find the innermost address-of easily
277 }
278 }
279
280 Expression * AddrRef::postmutate( AddressExpr * addrExpr ) {
281 PRINT( std::cerr << "addr ref at " << addrExpr << std::endl; )
282 if ( refDepth == 0 ) {
283 PRINT( std::cerr << "depth 0, get new depth..." << std::endl; )
284 // this is the innermost address-of in a chain, record depth D
285 if ( ! isIntrinsicReference( addrExpr->arg ) ) {
286 // try to avoid ?[?]
287 // 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.
288 refDepth = addrExpr->arg->result->referenceDepth();
289 PRINT( std::cerr << "arg not intrinsic reference, new depth is: " << refDepth << std::endl; )
290 } else {
291 assertf( false, "AddrRef : address-of should not have intrinsic reference argument: %s", toCString( addrExpr->arg ) );
292 }
293 }
294 if ( current ) { // this is the outermost address-of in a chain
295 PRINT( std::cerr << "current, depth is: " << refDepth << std::endl; )
296 Expression * ret = addrExpr;
297 while ( refDepth ) {
298 // add one dereference for each
299 ret = mkDeref( ret );
300 refDepth--;
301 }
302
303 // if addrExpr depth is 0, then the result is a pointer because the arg was depth 1 and not lvalue.
304 // This means the dereference result is not a reference, is lvalue, and one less pointer depth than
305 // the addrExpr. Thus the cast is meaningless.
306 // TODO: One thing to double check is whether it is possible for the types to differ outside of the single
307 // pointer level (i.e. can the base type of addrExpr differ from the type of addrExpr-arg?).
308 // If so then the cast might need to be added, conditional on a more sophisticated check.
309 if ( addCast && addrExpr->result->referenceDepth() != 0 ) {
310 PRINT( std::cerr << "adding cast to " << addrExpr->result << std::endl; )
311 return new CastExpr( ret, addrExpr->result->clone() );
312 }
313 return ret;
314 }
315 PRINT( std::cerr << "not current..." << std::endl; )
316 return addrExpr;
317 }
318
319 void AddrRef::premutate( ApplicationExpr * appExpr ) {
320 visit_children = false;
321 GuardValue( addCast );
322 handleNonAddr( appExpr );
323 for ( Expression *& arg : appExpr->args ) {
324 // each argument with address-of requires a cast
325 addCast = true;
326 arg = arg->acceptMutator( *visitor );
327 }
328 }
329
330 void AddrRef::premutate( SingleInit * ) {
331 GuardValue( addCast );
332 // each initialization context with address-of requires a cast
333 addCast = true;
334 }
335
336
337 Expression * ReferenceConversions::postmutate( AddressExpr * addrExpr ) {
338 // Inner expression may have been lvalue to reference conversion, which becomes an address expression.
339 // In this case, remove the outer address expression and return the argument.
340 // TODO: It's possible that this might catch too much and require a more sophisticated check.
341 return addrExpr;
342 }
343
344 Expression * ReferenceConversions::postmutate( CastExpr * castExpr ) {
345 // xxx - is it possible to convert directly between reference types with a different base? E.g.,
346 // int x;
347 // (double&)x;
348 // At the moment, I am working off of the assumption that this is illegal, thus the cast becomes redundant
349 // after this pass, so trash the cast altogether. If that changes, care must be taken to insert the correct
350 // pointer casts in the right places.
351
352 // Note: reference depth difference is the determining factor in what code is run, rather than whether something is
353 // reference type or not, since conversion still needs to occur when both types are references that differ in depth.
354
355 Type * destType = castExpr->result;
356 Type * srcType = castExpr->arg->result;
357 int depth1 = destType->referenceDepth();
358 int depth2 = srcType->referenceDepth();
359 int diff = depth1 - depth2;
360
361 if ( diff > 0 && ! srcType->get_lvalue() ) {
362 // rvalue to reference conversion -- introduce temporary
363 // know that reference depth of cast argument is 0, need to introduce n temporaries for reference depth of n, e.g.
364 // (int &&&)3;
365 // becomes
366 // int __ref_tmp_0 = 3;
367 // int & __ref_tmp_1 = _&_ref_tmp_0;
368 // int && __ref_tmp_2 = &__ref_tmp_1;
369 // &__ref_tmp_2;
370 // the last & comes from the remaining reference conversion code
371 SemanticWarning( castExpr->arg->location, Warning::RvalueToReferenceConversion, toCString( castExpr->arg ) );
372
373 static UniqueName tempNamer( "__ref_tmp_" );
374 ObjectDecl * temp = ObjectDecl::newObject( tempNamer.newName(), castExpr->arg->result->clone(), new SingleInit( castExpr->arg ) );
375 PRINT( std::cerr << "made temp: " << temp << std::endl; )
376 stmtsToAddBefore.push_back( new DeclStmt( temp ) );
377 for ( int i = 0; i < depth1-1; i++ ) { // xxx - maybe this should be diff-1? check how this works with reference type for srcType
378 ObjectDecl * newTemp = ObjectDecl::newObject( tempNamer.newName(), new ReferenceType( Type::Qualifiers(), temp->type->clone() ), new SingleInit( new AddressExpr( new VariableExpr( temp ) ) ) );
379 PRINT( std::cerr << "made temp" << i << ": " << newTemp << std::endl; )
380 stmtsToAddBefore.push_back( new DeclStmt( newTemp ) );
381 temp = newTemp;
382 }
383 // update diff so that remaining code works out correctly
384 castExpr->arg = new VariableExpr( temp );
385 PRINT( std::cerr << "update cast to: " << castExpr << std::endl; )
386 srcType = castExpr->arg->result;
387 depth2 = srcType->referenceDepth();
388 diff = depth1 - depth2;
389 assert( diff == 1 );
390 }
391
392 // handle conversion between different depths
393 PRINT (
394 if ( depth1 || depth2 ) {
395 std::cerr << "destType: " << destType << " / srcType: " << srcType << std::endl;
396 std::cerr << "depth: " << depth1 << " / " << depth2 << std::endl;
397 }
398 )
399 if ( diff > 0 ) {
400 // conversion to type with more depth (e.g. int & -> int &&): add address-of for each level of difference
401 Expression * ret = castExpr->arg;
402 for ( int i = 0; i < diff; ++i ) {
403 ret = new AddressExpr( ret );
404 }
405 if ( srcType->get_lvalue() && srcType->get_qualifiers() != strict_dynamic_cast<ReferenceType *>( destType )->base->get_qualifiers() ) {
406 // must keep cast if cast-to type is different from the actual type
407 castExpr->arg = ret;
408 return castExpr;
409 }
410 ret->env = castExpr->env;
411 delete ret->result;
412 ret->result = castExpr->result;
413 castExpr->env = nullptr;
414 castExpr->arg = nullptr;
415 castExpr->result = nullptr;
416 delete castExpr;
417 return ret;
418 } else if ( diff < 0 ) {
419 // conversion to type with less depth (e.g. int && -> int &): add dereferences for each level of difference
420 diff = -diff; // care only about magnitude now
421 Expression * ret = castExpr->arg;
422 for ( int i = 0; i < diff; ++i ) {
423 ret = mkDeref( ret );
424 // xxx - try removing one reference here? actually, looks like mkDeref already does this, so more closely look at the types generated.
425 }
426 if ( ! ResolvExpr::typesCompatibleIgnoreQualifiers( destType->stripReferences(), srcType->stripReferences(), SymTab::Indexer() ) ) {
427 // must keep cast if types are different
428 castExpr->arg = ret;
429 return castExpr;
430 }
431 ret->env = castExpr->env;
432 delete ret->result;
433 ret->result = castExpr->result;
434 ret->result->set_lvalue( true ); // ensure result is lvalue
435 castExpr->env = nullptr;
436 castExpr->arg = nullptr;
437 castExpr->result = nullptr;
438 delete castExpr;
439 return ret;
440 } else {
441 assert( diff == 0 );
442 // conversion between references of the same depth
443 if ( ResolvExpr::typesCompatible( castExpr->result, castExpr->arg->result, SymTab::Indexer() ) && castExpr->isGenerated ) {
444 // Remove useless generated casts
445 PRINT(
446 std::cerr << "types are compatible, removing cast: " << castExpr << std::endl;
447 std::cerr << "-- " << castExpr->result << std::endl;
448 std::cerr << "-- " << castExpr->arg->result << std::endl;
449 )
450 Expression * ret = castExpr->arg;
451 castExpr->arg = nullptr;
452 std::swap( castExpr->env, ret->env );
453 delete castExpr;
454 return ret;
455 }
456 return castExpr;
457 }
458 }
459
460 Type * ReferenceTypeElimination::postmutate( ReferenceType * refType ) {
461 Type * base = refType->base;
462 Type::Qualifiers qualifiers = refType->get_qualifiers();
463 refType->base = nullptr;
464 delete refType;
465 return new PointerType( qualifiers, base );
466 }
467
468 template<typename Func>
469 Expression * GeneralizedLvalue::applyTransformation( Expression * expr, Expression * arg, Func mkExpr ) {
470 if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( arg ) ) {
471 Expression * arg1 = commaExpr->arg1->clone();
472 Expression * arg2 = commaExpr->arg2->clone();
473 Expression * ret = new CommaExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ) );
474 ret->env = expr->env;
475 expr->env = nullptr;
476 delete expr;
477 return ret;
478 } else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( arg ) ) {
479 Expression * arg1 = condExpr->arg1->clone();
480 Expression * arg2 = condExpr->arg2->clone();
481 Expression * arg3 = condExpr->arg3->clone();
482 ConditionalExpr * ret = new ConditionalExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ), mkExpr( arg3 )->acceptMutator( *visitor ) );
483 ret->env = expr->env;
484 expr->env = nullptr;
485 delete expr;
486
487 // conditional expr type may not be either of the argument types, need to unify
488 using namespace ResolvExpr;
489 Type* commonType = nullptr;
490 TypeEnvironment newEnv;
491 AssertionSet needAssertions, haveAssertions;
492 OpenVarSet openVars;
493 unify( ret->arg2->result, ret->arg3->result, newEnv, needAssertions, haveAssertions, openVars, SymTab::Indexer(), commonType );
494 ret->result = commonType ? commonType : ret->arg2->result->clone();
495 return ret;
496 }
497 return expr;
498 }
499
500 Expression * GeneralizedLvalue::postmutate( MemberExpr * memExpr ) {
501 return applyTransformation( memExpr, memExpr->aggregate, [=]( Expression * aggr ) { return new MemberExpr( memExpr->member, aggr ); } );
502 }
503
504 Expression * GeneralizedLvalue::postmutate( AddressExpr * addrExpr ) {
505 return applyTransformation( addrExpr, addrExpr->arg, []( Expression * arg ) { return new AddressExpr( arg ); } );
506 }
507
508 Expression * CollapseAddrDeref::postmutate( AddressExpr * addrExpr ) {
509 Expression * arg = addrExpr->arg;
510 if ( isIntrinsicReference( arg ) ) {
511 std::string fname = InitTweak::getFunctionName( arg );
512 if ( fname == "*?" ) {
513 Expression *& arg0 = InitTweak::getCallArg( arg, 0 );
514 Expression * ret = arg0;
515 ret->set_env( addrExpr->env );
516 arg0 = nullptr;
517 addrExpr->env = nullptr;
518 delete addrExpr;
519 return ret;
520 }
521 } else if ( CastExpr * castExpr = dynamic_cast< CastExpr * > ( arg ) ) {
522 // need to move cast to pointer type out a level since address of pointer
523 // is not valid C code (can be introduced in prior passes, e.g., InstantiateGeneric)
524 if ( InitTweak::getPointerBase( castExpr->result ) ) {
525 addrExpr->arg = castExpr->arg;
526 castExpr->arg = addrExpr;
527 castExpr->result = new PointerType( Type::Qualifiers(), castExpr->result );
528 return castExpr;
529 }
530 }
531 return addrExpr;
532 }
533
534 Expression * CollapseAddrDeref::postmutate( ApplicationExpr * appExpr ) {
535 if ( isIntrinsicReference( appExpr ) ) {
536 std::string fname = InitTweak::getFunctionName( appExpr );
537 if ( fname == "*?" ) {
538 Expression * arg = InitTweak::getCallArg( appExpr, 0 );
539 // xxx - this isn't right, because it can remove casts that should be there...
540 // while ( CastExpr * castExpr = dynamic_cast< CastExpr * >( arg ) ) {
541 // arg = castExpr->get_arg();
542 // }
543 if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( arg ) ) {
544 Expression * ret = addrExpr->arg;
545 ret->env = appExpr->env;
546 addrExpr->arg = nullptr;
547 appExpr->env = nullptr;
548 delete appExpr;
549 return ret;
550 }
551 }
552 }
553 return appExpr;
554 }
555 } // namespace
556} // namespace GenPoly
557
558// Local Variables: //
559// tab-width: 4 //
560// mode: c++ //
561// compile-command: "make install" //
562// End: //
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