source: src/GenPoly/Lvalue.cc@ 2c04369

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 2c04369 was 2c04369, checked in by Andrew Beach <ajbeach@…>, 6 years ago

Fixed some problems in convert. One of which was better solved by removing the FindSpecialDeclarations hack.
  • Property mode set to 100644
File size: 23.7 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 : Andrew Beach
12// Last Modified On : Tue May 28 11:07:00 2019
13// Update Count : 6
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 /// Local helper for pass visitors that need to add reference operations.
45 struct WithDerefOp {
46 FunctionDecl * dereferenceOperator = nullptr;
47
48 // TODO: fold this into the general createDeref function??
49 Expression * mkDeref( Expression * arg ) {
50 if ( dereferenceOperator ) {
51 // note: reference depth can be arbitrarily deep here, so peel off the
52 // outermost pointer/reference, not just pointer because they are effecitvely
53 // equivalent in this pass
54 VariableExpr * deref = new VariableExpr( dereferenceOperator );
55 deref->result = new PointerType( Type::Qualifiers(), deref->result );
56 Type * base = InitTweak::getPointerBase( arg->result );
57 assertf( base, "expected pointer type in dereference (type was %s)",
58 toString( arg->result ).c_str() );
59 ApplicationExpr * ret = new ApplicationExpr( deref, { arg } );
60 delete ret->result;
61 ret->result = base->clone();
62 ret->result->set_lvalue( true );
63 return ret;
64 } else {
65 return UntypedExpr::createDeref( arg );
66 }
67 }
68
69 void previsit( FunctionDecl * funcDecl ) {
70 if ( dereferenceOperator ) return;
71 if ( funcDecl->get_name() != "*?" ) return;
72 if ( funcDecl->get_linkage() == LinkageSpec::Intrinsic ) return;
73 FunctionType * ftype = funcDecl->get_functionType();
74 if ( ftype->get_parameters().size() != 1 ) return;
75 DeclarationWithType * arg0 = ftype->get_parameters().front();
76 if ( arg0->get_type()->get_qualifiers() == Type::Qualifiers() ) return;
77 dereferenceOperator = funcDecl;
78 }
79 };
80
81 struct ReferenceConversions final : public WithStmtsToAdd, public WithDerefOp {
82 Expression * postmutate( CastExpr * castExpr );
83 Expression * postmutate( AddressExpr * addrExpr );
84 };
85
86 /// Intrinsic functions that take reference parameters don't REALLY take reference parameters -- their reference arguments must always be implicitly dereferenced.
87 struct FixIntrinsicArgs final : public WithDerefOp {
88 Expression * postmutate( ApplicationExpr * appExpr );
89 };
90
91 struct FixIntrinsicResult final : public WithGuards {
92 Expression * postmutate( ApplicationExpr * appExpr );
93 void premutate( FunctionDecl * funcDecl );
94 bool inIntrinsic = false;
95 };
96
97 /// Replace reference types with pointer types
98 struct ReferenceTypeElimination final {
99 Type * postmutate( ReferenceType * refType );
100 };
101
102 /// GCC-like Generalized Lvalues (which have since been removed from GCC)
103 /// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues
104 /// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c)
105 struct GeneralizedLvalue final : public WithVisitorRef<GeneralizedLvalue> {
106 Expression * postmutate( AddressExpr * addressExpr );
107 Expression * postmutate( MemberExpr * memExpr );
108
109 template<typename Func>
110 Expression * applyTransformation( Expression * expr, Expression * arg, Func mkExpr );
111 };
112
113 /// Removes redundant &*/*& pattern that this pass can generate
114 struct CollapseAddrDeref final {
115 Expression * postmutate( AddressExpr * addressExpr );
116 Expression * postmutate( ApplicationExpr * appExpr );
117 };
118
119 struct AddrRef final : public WithGuards, public WithVisitorRef<AddrRef>,
120 public WithShortCircuiting, public WithDerefOp {
121 void premutate( AddressExpr * addrExpr );
122 Expression * postmutate( AddressExpr * addrExpr );
123 void premutate( Expression * expr );
124 void premutate( ApplicationExpr * appExpr );
125 void premutate( SingleInit * init );
126
127 void handleNonAddr( Expression * );
128
129 bool first = true;
130 bool current = false;
131 int refDepth = 0;
132 bool addCast = false;
133 };
134 } // namespace
135
136 static bool referencesEliminated = false;
137 // used by UntypedExpr::createDeref to determine whether result type of dereference should be ReferenceType or value type.
138 bool referencesPermissable() {
139 return ! referencesEliminated;
140 }
141
142 void convertLvalue( std::list< Declaration* > & translationUnit ) {
143 PassVisitor<ReferenceConversions> refCvt;
144 PassVisitor<ReferenceTypeElimination> elim;
145 PassVisitor<GeneralizedLvalue> genLval;
146 PassVisitor<FixIntrinsicArgs> fixer;
147 PassVisitor<CollapseAddrDeref> collapser;
148 PassVisitor<AddrRef> addrRef;
149 PassVisitor<FixIntrinsicResult> intrinsicResults;
150 mutateAll( translationUnit, intrinsicResults );
151 mutateAll( translationUnit, addrRef );
152 mutateAll( translationUnit, refCvt );
153 mutateAll( translationUnit, fixer );
154 mutateAll( translationUnit, collapser );
155 mutateAll( translationUnit, genLval );
156 mutateAll( translationUnit, elim ); // last because other passes need reference types to work
157
158 // from this point forward, no other pass should create reference types.
159 referencesEliminated = true;
160 }
161
162 Expression * generalizedLvalue( Expression * expr ) {
163 PassVisitor<GeneralizedLvalue> genLval;
164 return expr->acceptMutator( genLval );
165 }
166
167 namespace {
168 // true for intrinsic function calls that return an lvalue in C
169 bool isIntrinsicReference( Expression * expr ) {
170 // known intrinsic-reference prelude functions
171 static std::set<std::string> lvalueFunctions = { "*?", "?[?]" };
172 if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) {
173 std::string fname = InitTweak::getFunctionName( untyped );
174 return lvalueFunctions.count(fname);
175 } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
176 if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) {
177 return func->linkage == LinkageSpec::Intrinsic && lvalueFunctions.count(func->name);
178 }
179 }
180 return false;
181 }
182
183 Expression * FixIntrinsicResult::postmutate( ApplicationExpr * appExpr ) {
184 if ( isIntrinsicReference( appExpr ) ) {
185 // eliminate reference types from intrinsic applications - now they return lvalues
186 ReferenceType * result = strict_dynamic_cast< ReferenceType * >( appExpr->result );
187 appExpr->result = result->base->clone();
188 appExpr->result->set_lvalue( true );
189 if ( ! inIntrinsic ) {
190 // when not in an intrinsic function, add a cast to
191 // don't add cast when in an intrinsic function, since they already have the cast
192 Expression * ret = new CastExpr( appExpr, result );
193 std::swap( ret->env, appExpr->env );
194 return ret;
195 }
196 delete result;
197 }
198 return appExpr;
199 }
200
201 void FixIntrinsicResult::premutate( FunctionDecl * funcDecl ) {
202 GuardValue( inIntrinsic );
203 inIntrinsic = funcDecl->linkage == LinkageSpec::Intrinsic;
204 }
205
206 Expression * FixIntrinsicArgs::postmutate( ApplicationExpr * appExpr ) {
207 // intrinsic functions don't really take reference-typed parameters, so they require an implicit dereference on their arguments.
208 if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
209 FunctionType * ftype = GenPoly::getFunctionType( function->get_type() );
210 assertf( ftype, "Function declaration does not have function type." );
211 // can be of differing lengths only when function is variadic
212 assertf( ftype->parameters.size() == appExpr->args.size() || ftype->isVarArgs, "ApplicationExpr args do not match formal parameter type." );
213
214
215 unsigned int i = 0;
216 const unsigned int end = ftype->parameters.size();
217 for ( auto p : unsafe_group_iterate( appExpr->args, ftype->parameters ) ) {
218 if (i == end) break;
219 Expression *& arg = std::get<0>( p );
220 Type * formal = std::get<1>( p )->get_type();
221 PRINT(
222 std::cerr << "pair<0>: " << arg << std::endl;
223 std::cerr << " -- " << arg->result << std::endl;
224 std::cerr << "pair<1>: " << formal << std::endl;
225 )
226 if ( dynamic_cast<ReferenceType*>( formal ) ) {
227 PRINT(
228 std::cerr << "===formal is reference" << std::endl;
229 )
230 // TODO: it's likely that the second condition should be ... && ! isIntrinsicReference( arg ), but this requires investigation.
231
232 if ( function->linkage != LinkageSpec::Intrinsic && isIntrinsicReference( arg ) ) {
233 // needed for definition of prelude functions, etc.
234 // if argument is dereference or array subscript, the result isn't REALLY a reference, but non-intrinsic functions expect a reference: take address
235
236 // NOTE: previously, this condition fixed
237 // void f(int *&);
238 // int & x = ...;
239 // f(&x);
240 // But now this is taken care of by a reference cast added by AddrRef. Need to find a new
241 // example or remove this branch.
242
243 PRINT(
244 std::cerr << "===is intrinsic arg in non-intrinsic call - adding address" << std::endl;
245 )
246 arg = new AddressExpr( arg );
247 // } else if ( function->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getPointerBase( arg->result ) ) {
248 } else if ( function->linkage == LinkageSpec::Intrinsic && arg->result->referenceDepth() != 0 ) {
249 // argument is a 'real' reference, but function expects a C lvalue: add a dereference to the reference-typed argument
250 PRINT(
251 std::cerr << "===is non-intrinsic arg in intrinsic call - adding deref to arg" << std::endl;
252 )
253 Type * baseType = InitTweak::getPointerBase( arg->result );
254 assertf( baseType, "parameter is reference, arg must be pointer or reference: %s", toString( arg->result ).c_str() );
255 PointerType * ptrType = new PointerType( Type::Qualifiers(), baseType->clone() );
256 delete arg->result;
257 arg->result = ptrType;
258 arg = mkDeref( arg );
259 // assertf( arg->result->referenceDepth() == 0, "Reference types should have been eliminated from intrinsic function calls, but weren't: %s", toCString( arg->result ) );
260 }
261 }
262 ++i;
263 }
264 }
265 return appExpr;
266 }
267
268 // idea: &&&E: get outer &, inner &
269 // at inner &, record depth D of reference type of argument of &
270 // at outer &, add D derefs.
271 void AddrRef::handleNonAddr( Expression * ) {
272 // non-address-of: reset status variables:
273 // * current expr is NOT the first address-of expr in an address-of chain
274 // * next seen address-of expr IS the first in the chain.
275 GuardValue( current );
276 GuardValue( first );
277 current = false;
278 first = true;
279 }
280
281 void AddrRef::premutate( Expression * expr ) {
282 handleNonAddr( expr );
283 GuardValue( addCast );
284 addCast = false;
285 }
286
287 void AddrRef::premutate( AddressExpr * ) {
288 GuardValue( current );
289 GuardValue( first );
290 current = first; // is this the first address-of in the chain?
291 first = false; // from here out, no longer possible for next address-of to be first in chain
292 if ( current ) { // this is the outermost address-of in a chain
293 GuardValue( refDepth );
294 refDepth = 0; // set depth to 0 so that postmutate can find the innermost address-of easily
295 }
296 }
297
298 Expression * AddrRef::postmutate( AddressExpr * addrExpr ) {
299 PRINT( std::cerr << "addr ref at " << addrExpr << std::endl; )
300 if ( refDepth == 0 ) {
301 PRINT( std::cerr << "depth 0, get new depth..." << std::endl; )
302 // this is the innermost address-of in a chain, record depth D
303 if ( ! isIntrinsicReference( addrExpr->arg ) ) {
304 // try to avoid ?[?]
305 // 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.
306 refDepth = addrExpr->arg->result->referenceDepth();
307 PRINT( std::cerr << "arg not intrinsic reference, new depth is: " << refDepth << std::endl; )
308 } else {
309 assertf( false, "AddrRef : address-of should not have intrinsic reference argument: %s", toCString( addrExpr->arg ) );
310 }
311 }
312 if ( current ) { // this is the outermost address-of in a chain
313 PRINT( std::cerr << "current, depth is: " << refDepth << std::endl; )
314 Expression * ret = addrExpr;
315 while ( refDepth ) {
316 // add one dereference for each
317 ret = mkDeref( ret );
318 refDepth--;
319 }
320
321 // if addrExpr depth is 0, then the result is a pointer because the arg was depth 1 and not lvalue.
322 // This means the dereference result is not a reference, is lvalue, and one less pointer depth than
323 // the addrExpr. Thus the cast is meaningless.
324 // TODO: One thing to double check is whether it is possible for the types to differ outside of the single
325 // pointer level (i.e. can the base type of addrExpr differ from the type of addrExpr-arg?).
326 // If so then the cast might need to be added, conditional on a more sophisticated check.
327 if ( addCast && addrExpr->result->referenceDepth() != 0 ) {
328 PRINT( std::cerr << "adding cast to " << addrExpr->result << std::endl; )
329 return new CastExpr( ret, addrExpr->result->clone() );
330 }
331 return ret;
332 }
333 PRINT( std::cerr << "not current..." << std::endl; )
334 return addrExpr;
335 }
336
337 void AddrRef::premutate( ApplicationExpr * appExpr ) {
338 visit_children = false;
339 GuardValue( addCast );
340 handleNonAddr( appExpr );
341 for ( Expression *& arg : appExpr->args ) {
342 // each argument with address-of requires a cast
343 addCast = true;
344 arg = arg->acceptMutator( *visitor );
345 }
346 }
347
348 void AddrRef::premutate( SingleInit * ) {
349 GuardValue( addCast );
350 // each initialization context with address-of requires a cast
351 addCast = true;
352 }
353
354
355 Expression * ReferenceConversions::postmutate( AddressExpr * addrExpr ) {
356 // Inner expression may have been lvalue to reference conversion, which becomes an address expression.
357 // In this case, remove the outer address expression and return the argument.
358 // TODO: It's possible that this might catch too much and require a more sophisticated check.
359 return addrExpr;
360 }
361
362 Expression * ReferenceConversions::postmutate( CastExpr * castExpr ) {
363 // xxx - is it possible to convert directly between reference types with a different base? E.g.,
364 // int x;
365 // (double&)x;
366 // At the moment, I am working off of the assumption that this is illegal, thus the cast becomes redundant
367 // after this pass, so trash the cast altogether. If that changes, care must be taken to insert the correct
368 // pointer casts in the right places.
369
370 // Note: reference depth difference is the determining factor in what code is run, rather than whether something is
371 // reference type or not, since conversion still needs to occur when both types are references that differ in depth.
372
373 Type * destType = castExpr->result;
374 Type * srcType = castExpr->arg->result;
375 int depth1 = destType->referenceDepth();
376 int depth2 = srcType->referenceDepth();
377 int diff = depth1 - depth2;
378
379 if ( diff > 0 && ! srcType->get_lvalue() ) {
380 // rvalue to reference conversion -- introduce temporary
381 // know that reference depth of cast argument is 0, need to introduce n temporaries for reference depth of n, e.g.
382 // (int &&&)3;
383 // becomes
384 // int __ref_tmp_0 = 3;
385 // int & __ref_tmp_1 = _&_ref_tmp_0;
386 // int && __ref_tmp_2 = &__ref_tmp_1;
387 // &__ref_tmp_2;
388 // the last & comes from the remaining reference conversion code
389 SemanticWarning( castExpr->arg->location, Warning::RvalueToReferenceConversion, toCString( castExpr->arg ) );
390
391 static UniqueName tempNamer( "__ref_tmp_" );
392 ObjectDecl * temp = ObjectDecl::newObject( tempNamer.newName(), castExpr->arg->result->clone(), new SingleInit( castExpr->arg ) );
393 PRINT( std::cerr << "made temp: " << temp << std::endl; )
394 stmtsToAddBefore.push_back( new DeclStmt( temp ) );
395 for ( int i = 0; i < depth1-1; i++ ) { // xxx - maybe this should be diff-1? check how this works with reference type for srcType
396 ObjectDecl * newTemp = ObjectDecl::newObject( tempNamer.newName(), new ReferenceType( Type::Qualifiers(), temp->type->clone() ), new SingleInit( new AddressExpr( new VariableExpr( temp ) ) ) );
397 PRINT( std::cerr << "made temp" << i << ": " << newTemp << std::endl; )
398 stmtsToAddBefore.push_back( new DeclStmt( newTemp ) );
399 temp = newTemp;
400 }
401 // update diff so that remaining code works out correctly
402 castExpr->arg = new VariableExpr( temp );
403 PRINT( std::cerr << "update cast to: " << castExpr << std::endl; )
404 srcType = castExpr->arg->result;
405 depth2 = srcType->referenceDepth();
406 diff = depth1 - depth2;
407 assert( diff == 1 );
408 }
409
410 // handle conversion between different depths
411 PRINT (
412 if ( depth1 || depth2 ) {
413 std::cerr << "destType: " << destType << " / srcType: " << srcType << std::endl;
414 std::cerr << "depth: " << depth1 << " / " << depth2 << std::endl;
415 }
416 )
417 if ( diff > 0 ) {
418 // conversion to type with more depth (e.g. int & -> int &&): add address-of for each level of difference
419 Expression * ret = castExpr->arg;
420 for ( int i = 0; i < diff; ++i ) {
421 ret = new AddressExpr( ret );
422 }
423 if ( srcType->get_lvalue() && ! ResolvExpr::typesCompatible( srcType, strict_dynamic_cast<ReferenceType *>( destType )->base, SymTab::Indexer() ) ) {
424 // must keep cast if cast-to type is different from the actual type
425 castExpr->arg = ret;
426 return castExpr;
427 }
428 ret->env = castExpr->env;
429 delete ret->result;
430 ret->result = castExpr->result;
431 castExpr->env = nullptr;
432 castExpr->arg = nullptr;
433 castExpr->result = nullptr;
434 delete castExpr;
435 return ret;
436 } else if ( diff < 0 ) {
437 // conversion to type with less depth (e.g. int && -> int &): add dereferences for each level of difference
438 diff = -diff; // care only about magnitude now
439 Expression * ret = castExpr->arg;
440 for ( int i = 0; i < diff; ++i ) {
441 ret = mkDeref( ret );
442 // xxx - try removing one reference here? actually, looks like mkDeref already does this, so more closely look at the types generated.
443 }
444 if ( ! ResolvExpr::typesCompatibleIgnoreQualifiers( destType->stripReferences(), srcType->stripReferences(), SymTab::Indexer() ) ) {
445 // must keep cast if types are different
446 castExpr->arg = ret;
447 return castExpr;
448 }
449 ret->env = castExpr->env;
450 delete ret->result;
451 ret->result = castExpr->result;
452 ret->result->set_lvalue( true ); // ensure result is lvalue
453 castExpr->env = nullptr;
454 castExpr->arg = nullptr;
455 castExpr->result = nullptr;
456 delete castExpr;
457 return ret;
458 } else {
459 assert( diff == 0 );
460 // conversion between references of the same depth
461 if ( ResolvExpr::typesCompatible( castExpr->result, castExpr->arg->result, SymTab::Indexer() ) && castExpr->isGenerated ) {
462 // Remove useless generated casts
463 PRINT(
464 std::cerr << "types are compatible, removing cast: " << castExpr << std::endl;
465 std::cerr << "-- " << castExpr->result << std::endl;
466 std::cerr << "-- " << castExpr->arg->result << std::endl;
467 )
468 Expression * ret = castExpr->arg;
469 castExpr->arg = nullptr;
470 std::swap( castExpr->env, ret->env );
471 delete castExpr;
472 return ret;
473 }
474 return castExpr;
475 }
476 }
477
478 Type * ReferenceTypeElimination::postmutate( ReferenceType * refType ) {
479 Type * base = refType->base;
480 Type::Qualifiers qualifiers = refType->get_qualifiers();
481 refType->base = nullptr;
482 delete refType;
483 return new PointerType( qualifiers, base );
484 }
485
486 template<typename Func>
487 Expression * GeneralizedLvalue::applyTransformation( Expression * expr, Expression * arg, Func mkExpr ) {
488 if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( arg ) ) {
489 Expression * arg1 = commaExpr->arg1->clone();
490 Expression * arg2 = commaExpr->arg2->clone();
491 Expression * ret = new CommaExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ) );
492 ret->env = expr->env;
493 expr->env = nullptr;
494 delete expr;
495 return ret;
496 } else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( arg ) ) {
497 Expression * arg1 = condExpr->arg1->clone();
498 Expression * arg2 = condExpr->arg2->clone();
499 Expression * arg3 = condExpr->arg3->clone();
500 ConditionalExpr * ret = new ConditionalExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ), mkExpr( arg3 )->acceptMutator( *visitor ) );
501 ret->env = expr->env;
502 expr->env = nullptr;
503 delete expr;
504
505 // conditional expr type may not be either of the argument types, need to unify
506 using namespace ResolvExpr;
507 Type* commonType = nullptr;
508 TypeEnvironment newEnv;
509 AssertionSet needAssertions, haveAssertions;
510 OpenVarSet openVars;
511 unify( ret->arg2->result, ret->arg3->result, newEnv, needAssertions, haveAssertions, openVars, SymTab::Indexer(), commonType );
512 ret->result = commonType ? commonType : ret->arg2->result->clone();
513 return ret;
514 }
515 return expr;
516 }
517
518 Expression * GeneralizedLvalue::postmutate( MemberExpr * memExpr ) {
519 return applyTransformation( memExpr, memExpr->aggregate, [=]( Expression * aggr ) { return new MemberExpr( memExpr->member, aggr ); } );
520 }
521
522 Expression * GeneralizedLvalue::postmutate( AddressExpr * addrExpr ) {
523 return applyTransformation( addrExpr, addrExpr->arg, []( Expression * arg ) { return new AddressExpr( arg ); } );
524 }
525
526 Expression * CollapseAddrDeref::postmutate( AddressExpr * addrExpr ) {
527 Expression * arg = addrExpr->arg;
528 if ( isIntrinsicReference( arg ) ) {
529 std::string fname = InitTweak::getFunctionName( arg );
530 if ( fname == "*?" ) {
531 Expression *& arg0 = InitTweak::getCallArg( arg, 0 );
532 Expression * ret = arg0;
533 ret->set_env( addrExpr->env );
534 arg0 = nullptr;
535 addrExpr->env = nullptr;
536 delete addrExpr;
537 return ret;
538 }
539 } else if ( CastExpr * castExpr = dynamic_cast< CastExpr * > ( arg ) ) {
540 // need to move cast to pointer type out a level since address of pointer
541 // is not valid C code (can be introduced in prior passes, e.g., InstantiateGeneric)
542 if ( InitTweak::getPointerBase( castExpr->result ) ) {
543 addrExpr->arg = castExpr->arg;
544 castExpr->arg = addrExpr;
545 castExpr->result = new PointerType( Type::Qualifiers(), castExpr->result );
546 return castExpr;
547 }
548 }
549 return addrExpr;
550 }
551
552 Expression * CollapseAddrDeref::postmutate( ApplicationExpr * appExpr ) {
553 if ( isIntrinsicReference( appExpr ) ) {
554 std::string fname = InitTweak::getFunctionName( appExpr );
555 if ( fname == "*?" ) {
556 Expression * arg = InitTweak::getCallArg( appExpr, 0 );
557 // xxx - this isn't right, because it can remove casts that should be there...
558 // while ( CastExpr * castExpr = dynamic_cast< CastExpr * >( arg ) ) {
559 // arg = castExpr->get_arg();
560 // }
561 if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( arg ) ) {
562 Expression * ret = addrExpr->arg;
563 ret->env = appExpr->env;
564 addrExpr->arg = nullptr;
565 appExpr->env = nullptr;
566 delete appExpr;
567 return ret;
568 }
569 }
570 }
571 return appExpr;
572 }
573 } // namespace
574} // namespace GenPoly
575
576// Local Variables: //
577// tab-width: 4 //
578// mode: c++ //
579// compile-command: "make install" //
580// End: //
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