source: src/GenPoly/Lvalue.cc@ b96d7c1

ADT arm-eh ast-experimental cleanup-dtors enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since b96d7c1 was 85b2300, checked in by Rob Schluntz <rschlunt@…>, 7 years ago

Minor code cleanup
  • Property mode set to 100644
File size: 23.0 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 an lvalue in C
149 bool isIntrinsicReference( Expression * expr ) {
150 // known intrinsic-reference prelude functions
151 static std::set<std::string> lvalueFunctions = { "*?", "?[?]" };
152 if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) {
153 std::string fname = InitTweak::getFunctionName( untyped );
154 return lvalueFunctions.count(fname);
155 } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
156 if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) {
157 return func->linkage == LinkageSpec::Intrinsic && lvalueFunctions.count(func->name);
158 }
159 }
160 return false;
161 }
162
163 Expression * FixIntrinsicResult::postmutate( ApplicationExpr * appExpr ) {
164 if ( isIntrinsicReference( appExpr ) ) {
165 // eliminate reference types from intrinsic applications - now they return lvalues
166 ReferenceType * result = strict_dynamic_cast< ReferenceType * >( appExpr->result );
167 appExpr->result = result->base->clone();
168 appExpr->result->set_lvalue( true );
169 if ( ! inIntrinsic ) {
170 // when not in an intrinsic function, add a cast to
171 // don't add cast when in an intrinsic function, since they already have the cast
172 Expression * ret = new CastExpr( appExpr, result );
173 std::swap( ret->env, appExpr->env );
174 return ret;
175 }
176 delete result;
177 }
178 return appExpr;
179 }
180
181 void FixIntrinsicResult::premutate( FunctionDecl * funcDecl ) {
182 GuardValue( inIntrinsic );
183 inIntrinsic = funcDecl->linkage == LinkageSpec::Intrinsic;
184 }
185
186 Expression * FixIntrinsicArgs::postmutate( ApplicationExpr * appExpr ) {
187 // intrinsic functions don't really take reference-typed parameters, so they require an implicit dereference on their arguments.
188 if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
189 FunctionType * ftype = GenPoly::getFunctionType( function->get_type() );
190 assertf( ftype, "Function declaration does not have function type." );
191 // can be of differing lengths only when function is variadic
192 assertf( ftype->parameters.size() == appExpr->args.size() || ftype->isVarArgs, "ApplicationExpr args do not match formal parameter type." );
193
194
195 unsigned int i = 0;
196 const unsigned int end = ftype->parameters.size();
197 for ( auto p : unsafe_group_iterate( appExpr->args, ftype->parameters ) ) {
198 if (i == end) break;
199 Expression *& arg = std::get<0>( p );
200 Type * formal = std::get<1>( p )->get_type();
201 PRINT(
202 std::cerr << "pair<0>: " << arg << std::endl;
203 std::cerr << " -- " << arg->result << std::endl;
204 std::cerr << "pair<1>: " << formal << std::endl;
205 )
206 if ( dynamic_cast<ReferenceType*>( formal ) ) {
207 PRINT(
208 std::cerr << "===formal is reference" << std::endl;
209 )
210 // TODO: it's likely that the second condition should be ... && ! isIntrinsicReference( arg ), but this requires investigation.
211
212 if ( function->linkage != LinkageSpec::Intrinsic && isIntrinsicReference( arg ) ) {
213 // needed for definition of prelude functions, etc.
214 // if argument is dereference or array subscript, the result isn't REALLY a reference, but non-intrinsic functions expect a reference: take address
215
216 // NOTE: previously, this condition fixed
217 // void f(int *&);
218 // int & x = ...;
219 // f(&x);
220 // But now this is taken care of by a reference cast added by AddrRef. Need to find a new
221 // example or remove this branch.
222
223 PRINT(
224 std::cerr << "===is intrinsic arg in non-intrinsic call - adding address" << std::endl;
225 )
226 arg = new AddressExpr( arg );
227 // } else if ( function->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getPointerBase( arg->result ) ) {
228 } else if ( function->linkage == LinkageSpec::Intrinsic && arg->result->referenceDepth() != 0 ) {
229 // argument is a 'real' reference, but function expects a C lvalue: add a dereference to the reference-typed argument
230 PRINT(
231 std::cerr << "===is non-intrinsic arg in intrinsic call - adding deref to arg" << std::endl;
232 )
233 Type * baseType = InitTweak::getPointerBase( arg->result );
234 assertf( baseType, "parameter is reference, arg must be pointer or reference: %s", toString( arg->result ).c_str() );
235 PointerType * ptrType = new PointerType( Type::Qualifiers(), baseType->clone() );
236 delete arg->result;
237 arg->result = ptrType;
238 arg = mkDeref( arg );
239 // assertf( arg->result->referenceDepth() == 0, "Reference types should have been eliminated from intrinsic function calls, but weren't: %s", toCString( arg->result ) );
240 }
241 }
242 ++i;
243 }
244 }
245 return appExpr;
246 }
247
248 // idea: &&&E: get outer &, inner &
249 // at inner &, record depth D of reference type of argument of &
250 // at outer &, add D derefs.
251 void AddrRef::handleNonAddr( Expression * ) {
252 // non-address-of: reset status variables:
253 // * current expr is NOT the first address-of expr in an address-of chain
254 // * next seen address-of expr IS the first in the chain.
255 GuardValue( current );
256 GuardValue( first );
257 current = false;
258 first = true;
259 }
260
261 void AddrRef::premutate( Expression * expr ) {
262 handleNonAddr( expr );
263 GuardValue( addCast );
264 addCast = false;
265 }
266
267 void AddrRef::premutate( AddressExpr * ) {
268 GuardValue( current );
269 GuardValue( first );
270 current = first; // is this the first address-of in the chain?
271 first = false; // from here out, no longer possible for next address-of to be first in chain
272 if ( current ) { // this is the outermost address-of in a chain
273 GuardValue( refDepth );
274 refDepth = 0; // set depth to 0 so that postmutate can find the innermost address-of easily
275 }
276 }
277
278 Expression * AddrRef::postmutate( AddressExpr * addrExpr ) {
279 PRINT( std::cerr << "addr ref at " << addrExpr << std::endl; )
280 if ( refDepth == 0 ) {
281 PRINT( std::cerr << "depth 0, get new depth..." << std::endl; )
282 // this is the innermost address-of in a chain, record depth D
283 if ( ! isIntrinsicReference( addrExpr->arg ) ) {
284 // try to avoid ?[?]
285 // 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.
286 refDepth = addrExpr->arg->result->referenceDepth();
287 PRINT( std::cerr << "arg not intrinsic reference, new depth is: " << refDepth << std::endl; )
288 } else {
289 assertf( false, "AddrRef : address-of should not have intrinsic reference argument: %s", toCString( addrExpr->arg ) );
290 }
291 }
292 if ( current ) { // this is the outermost address-of in a chain
293 PRINT( std::cerr << "current, depth is: " << refDepth << std::endl; )
294 Expression * ret = addrExpr;
295 while ( refDepth ) {
296 // add one dereference for each
297 ret = mkDeref( ret );
298 refDepth--;
299 }
300
301 // if addrExpr depth is 0, then the result is a pointer because the arg was depth 1 and not lvalue.
302 // This means the dereference result is not a reference, is lvalue, and one less pointer depth than
303 // the addrExpr. Thus the cast is meaningless.
304 // TODO: One thing to double check is whether it is possible for the types to differ outside of the single
305 // pointer level (i.e. can the base type of addrExpr differ from the type of addrExpr-arg?).
306 // If so then the cast might need to be added, conditional on a more sophisticated check.
307 if ( addCast && addrExpr->result->referenceDepth() != 0 ) {
308 PRINT( std::cerr << "adding cast to " << addrExpr->result << std::endl; )
309 return new CastExpr( ret, addrExpr->result->clone() );
310 }
311 return ret;
312 }
313 PRINT( std::cerr << "not current..." << std::endl; )
314 return addrExpr;
315 }
316
317 void AddrRef::premutate( ApplicationExpr * appExpr ) {
318 visit_children = false;
319 GuardValue( addCast );
320 handleNonAddr( appExpr );
321 for ( Expression *& arg : appExpr->args ) {
322 // each argument with address-of requires a cast
323 addCast = true;
324 arg = arg->acceptMutator( *visitor );
325 }
326 }
327
328 void AddrRef::premutate( SingleInit * ) {
329 GuardValue( addCast );
330 // each initialization context with address-of requires a cast
331 addCast = true;
332 }
333
334
335 Expression * ReferenceConversions::postmutate( AddressExpr * addrExpr ) {
336 // Inner expression may have been lvalue to reference conversion, which becomes an address expression.
337 // In this case, remove the outer address expression and return the argument.
338 // TODO: It's possible that this might catch too much and require a more sophisticated check.
339 return addrExpr;
340 }
341
342 Expression * ReferenceConversions::postmutate( CastExpr * castExpr ) {
343 // xxx - is it possible to convert directly between reference types with a different base? E.g.,
344 // int x;
345 // (double&)x;
346 // At the moment, I am working off of the assumption that this is illegal, thus the cast becomes redundant
347 // after this pass, so trash the cast altogether. If that changes, care must be taken to insert the correct
348 // pointer casts in the right places.
349
350 // Note: reference depth difference is the determining factor in what code is run, rather than whether something is
351 // reference type or not, since conversion still needs to occur when both types are references that differ in depth.
352
353 Type * destType = castExpr->result;
354 Type * srcType = castExpr->arg->result;
355 int depth1 = destType->referenceDepth();
356 int depth2 = srcType->referenceDepth();
357 int diff = depth1 - depth2;
358
359 if ( diff > 0 && ! srcType->get_lvalue() ) {
360 // rvalue to reference conversion -- introduce temporary
361 // know that reference depth of cast argument is 0, need to introduce n temporaries for reference depth of n, e.g.
362 // (int &&&)3;
363 // becomes
364 // int __ref_tmp_0 = 3;
365 // int & __ref_tmp_1 = _&_ref_tmp_0;
366 // int && __ref_tmp_2 = &__ref_tmp_1;
367 // &__ref_tmp_2;
368 // the last & comes from the remaining reference conversion code
369 SemanticWarning( castExpr->arg->location, Warning::RvalueToReferenceConversion, toCString( castExpr->arg ) );
370
371 static UniqueName tempNamer( "__ref_tmp_" );
372 ObjectDecl * temp = ObjectDecl::newObject( tempNamer.newName(), castExpr->arg->result->clone(), new SingleInit( castExpr->arg ) );
373 PRINT( std::cerr << "made temp: " << temp << std::endl; )
374 stmtsToAddBefore.push_back( new DeclStmt( temp ) );
375 for ( int i = 0; i < depth1-1; i++ ) { // xxx - maybe this should be diff-1? check how this works with reference type for srcType
376 ObjectDecl * newTemp = ObjectDecl::newObject( tempNamer.newName(), new ReferenceType( Type::Qualifiers(), temp->type->clone() ), new SingleInit( new AddressExpr( new VariableExpr( temp ) ) ) );
377 PRINT( std::cerr << "made temp" << i << ": " << newTemp << std::endl; )
378 stmtsToAddBefore.push_back( new DeclStmt( newTemp ) );
379 temp = newTemp;
380 }
381 // update diff so that remaining code works out correctly
382 castExpr->arg = new VariableExpr( temp );
383 PRINT( std::cerr << "update cast to: " << castExpr << std::endl; )
384 srcType = castExpr->arg->result;
385 depth2 = srcType->referenceDepth();
386 diff = depth1 - depth2;
387 assert( diff == 1 );
388 }
389
390 // handle conversion between different depths
391 PRINT (
392 if ( depth1 || depth2 ) {
393 std::cerr << "destType: " << destType << " / srcType: " << srcType << std::endl;
394 std::cerr << "depth: " << depth1 << " / " << depth2 << std::endl;
395 }
396 )
397 if ( diff > 0 ) {
398 // conversion to type with more depth (e.g. int & -> int &&): add address-of for each level of difference
399 Expression * ret = castExpr->arg;
400 for ( int i = 0; i < diff; ++i ) {
401 ret = new AddressExpr( ret );
402 }
403 if ( srcType->get_lvalue() && ! ResolvExpr::typesCompatible( srcType, strict_dynamic_cast<ReferenceType *>( destType )->base, SymTab::Indexer() ) ) {
404 // must keep cast if cast-to type is different from the actual type
405 castExpr->arg = ret;
406 return castExpr;
407 }
408 ret->env = castExpr->env;
409 delete ret->result;
410 ret->result = castExpr->result;
411 castExpr->env = nullptr;
412 castExpr->arg = nullptr;
413 castExpr->result = nullptr;
414 delete castExpr;
415 return ret;
416 } else if ( diff < 0 ) {
417 // conversion to type with less depth (e.g. int && -> int &): add dereferences for each level of difference
418 diff = -diff; // care only about magnitude now
419 Expression * ret = castExpr->arg;
420 for ( int i = 0; i < diff; ++i ) {
421 ret = mkDeref( ret );
422 // xxx - try removing one reference here? actually, looks like mkDeref already does this, so more closely look at the types generated.
423 }
424 if ( ! ResolvExpr::typesCompatibleIgnoreQualifiers( destType->stripReferences(), srcType->stripReferences(), SymTab::Indexer() ) ) {
425 // must keep cast if types are different
426 castExpr->arg = ret;
427 return castExpr;
428 }
429 ret->env = castExpr->env;
430 delete ret->result;
431 ret->result = castExpr->result;
432 ret->result->set_lvalue( true ); // ensure result is lvalue
433 castExpr->env = nullptr;
434 castExpr->arg = nullptr;
435 castExpr->result = nullptr;
436 delete castExpr;
437 return ret;
438 } else {
439 assert( diff == 0 );
440 // conversion between references of the same depth
441 if ( ResolvExpr::typesCompatible( castExpr->result, castExpr->arg->result, SymTab::Indexer() ) && castExpr->isGenerated ) {
442 // Remove useless generated casts
443 PRINT(
444 std::cerr << "types are compatible, removing cast: " << castExpr << std::endl;
445 std::cerr << "-- " << castExpr->result << std::endl;
446 std::cerr << "-- " << castExpr->arg->result << std::endl;
447 )
448 Expression * ret = castExpr->arg;
449 castExpr->arg = nullptr;
450 std::swap( castExpr->env, ret->env );
451 delete castExpr;
452 return ret;
453 }
454 return castExpr;
455 }
456 }
457
458 Type * ReferenceTypeElimination::postmutate( ReferenceType * refType ) {
459 Type * base = refType->base;
460 Type::Qualifiers qualifiers = refType->get_qualifiers();
461 refType->base = nullptr;
462 delete refType;
463 return new PointerType( qualifiers, base );
464 }
465
466 template<typename Func>
467 Expression * GeneralizedLvalue::applyTransformation( Expression * expr, Expression * arg, Func mkExpr ) {
468 if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( arg ) ) {
469 Expression * arg1 = commaExpr->arg1->clone();
470 Expression * arg2 = commaExpr->arg2->clone();
471 Expression * ret = new CommaExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ) );
472 ret->env = expr->env;
473 expr->env = nullptr;
474 delete expr;
475 return ret;
476 } else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( arg ) ) {
477 Expression * arg1 = condExpr->arg1->clone();
478 Expression * arg2 = condExpr->arg2->clone();
479 Expression * arg3 = condExpr->arg3->clone();
480 ConditionalExpr * ret = new ConditionalExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ), mkExpr( arg3 )->acceptMutator( *visitor ) );
481 ret->env = expr->env;
482 expr->env = nullptr;
483 delete expr;
484
485 // conditional expr type may not be either of the argument types, need to unify
486 using namespace ResolvExpr;
487 Type* commonType = nullptr;
488 TypeEnvironment newEnv;
489 AssertionSet needAssertions, haveAssertions;
490 OpenVarSet openVars;
491 unify( ret->arg2->result, ret->arg3->result, newEnv, needAssertions, haveAssertions, openVars, SymTab::Indexer(), commonType );
492 ret->result = commonType ? commonType : ret->arg2->result->clone();
493 return ret;
494 }
495 return expr;
496 }
497
498 Expression * GeneralizedLvalue::postmutate( MemberExpr * memExpr ) {
499 return applyTransformation( memExpr, memExpr->aggregate, [=]( Expression * aggr ) { return new MemberExpr( memExpr->member, aggr ); } );
500 }
501
502 Expression * GeneralizedLvalue::postmutate( AddressExpr * addrExpr ) {
503 return applyTransformation( addrExpr, addrExpr->arg, []( Expression * arg ) { return new AddressExpr( arg ); } );
504 }
505
506 Expression * CollapseAddrDeref::postmutate( AddressExpr * addrExpr ) {
507 Expression * arg = addrExpr->arg;
508 if ( isIntrinsicReference( arg ) ) {
509 std::string fname = InitTweak::getFunctionName( arg );
510 if ( fname == "*?" ) {
511 Expression *& arg0 = InitTweak::getCallArg( arg, 0 );
512 Expression * ret = arg0;
513 ret->set_env( addrExpr->env );
514 arg0 = nullptr;
515 addrExpr->env = nullptr;
516 delete addrExpr;
517 return ret;
518 }
519 } else if ( CastExpr * castExpr = dynamic_cast< CastExpr * > ( arg ) ) {
520 // need to move cast to pointer type out a level since address of pointer
521 // is not valid C code (can be introduced in prior passes, e.g., InstantiateGeneric)
522 if ( InitTweak::getPointerBase( castExpr->result ) ) {
523 addrExpr->arg = castExpr->arg;
524 castExpr->arg = addrExpr;
525 castExpr->result = new PointerType( Type::Qualifiers(), castExpr->result );
526 return castExpr;
527 }
528 }
529 return addrExpr;
530 }
531
532 Expression * CollapseAddrDeref::postmutate( ApplicationExpr * appExpr ) {
533 if ( isIntrinsicReference( appExpr ) ) {
534 std::string fname = InitTweak::getFunctionName( appExpr );
535 if ( fname == "*?" ) {
536 Expression * arg = InitTweak::getCallArg( appExpr, 0 );
537 // xxx - this isn't right, because it can remove casts that should be there...
538 // while ( CastExpr * castExpr = dynamic_cast< CastExpr * >( arg ) ) {
539 // arg = castExpr->get_arg();
540 // }
541 if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( arg ) ) {
542 Expression * ret = addrExpr->arg;
543 ret->env = appExpr->env;
544 addrExpr->arg = nullptr;
545 appExpr->env = nullptr;
546 delete appExpr;
547 return ret;
548 }
549 }
550 }
551 return appExpr;
552 }
553 } // namespace
554} // namespace GenPoly
555
556// Local Variables: //
557// tab-width: 4 //
558// mode: c++ //
559// compile-command: "make install" //
560// End: //
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