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source: src/GenPoly/Lvalue.cc @ 8a97248

ADTast-experimental

Last change on this file since 8a97248 was 9939dc3, checked in by Andrew Beach <ajbeach@…>, 2 years ago
Reduced the number of object files linked into the demangler. Some of the divisions are rather odd, Lvalue2 and FixMain2, but they should be a better base to work from. Also improved the calling of the impurity detector visitors slightly.
Property mode set to `100644`
File size: 23.4 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 : Mon May 16 14:09:00 2022
13	// Update Count : 8
14	//
15
16	#include <cassert> // for strict_dynamic_cast
17	#include <string> // for string
18
19	#include "Common/UniqueName.h"
20	#include "Common/PassVisitor.h"
21	#include "GenPoly.h" // for isPolyType
22	#include "Lvalue.h"
23
24	#include "InitTweak/InitTweak.h"
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/LinkageSpec.h" // for Spec, isBuiltin, Intrinsic
30	#include "SynTree/Declaration.h" // for Declaration, FunctionDecl
31	#include "SynTree/Expression.h" // for Expression, ConditionalExpr
32	#include "SynTree/Mutator.h" // for mutateAll, Mutator
33	#include "SynTree/Statement.h" // for ReturnStmt, Statement (ptr o...
34	#include "SynTree/Type.h" // for PointerType, Type, FunctionType
35	#include "SynTree/Visitor.h" // for Visitor, acceptAll
36	#include "Validate/FindSpecialDecls.h" // for dereferenceOperator
37
38	#if 0
39	#define PRINT(x) x
40	#else
41	#define PRINT(x)
42	#endif
43
44	namespace GenPoly {
45	namespace {
46	// TODO: fold this into the general createDeref function??
47	Expression * mkDeref( Expression * arg ) {
48	if ( Validate::dereferenceOperator ) {
49	// 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
50	VariableExpr * deref = new VariableExpr( Validate::dereferenceOperator );
51	deref->result = new PointerType( Type::Qualifiers(), deref->result );
52	Type * base = InitTweak::getPointerBase( arg->result );
53	assertf( base, "expected pointer type in dereference (type was %s)", toString( arg->result ).c_str() );
54	ApplicationExpr * ret = new ApplicationExpr( deref, { arg } );
55	delete ret->result;
56	ret->result = base->clone();
57	return ret;
58	} else {
59	return UntypedExpr::createDeref( arg );
60	}
61	}
62
63	struct ReferenceConversions final : public WithStmtsToAdd, public WithGuards {
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	enum {
75	NoSkip,
76	Skip,
77	SkipInProgress
78	} skip = NoSkip;
79
80	void premutate( AsmExpr * ) { GuardValue( skip ); skip = Skip; }
81	void premutate( ApplicationExpr * ) { GuardValue( skip ); skip = (skip == Skip) ? SkipInProgress : NoSkip; }
82
83
84	Expression * postmutate( ApplicationExpr * appExpr );
85	void premutate( FunctionDecl * funcDecl );
86	bool inIntrinsic = false;
87	};
88
89	/// Replace reference types with pointer types
90	struct ReferenceTypeElimination final {
91	Type * postmutate( ReferenceType * refType );
92	};
93
94	/// GCC-like Generalized Lvalues (which have since been removed from GCC)
95	/// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues
96	/// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c)
97	struct GeneralizedLvalue final : public WithVisitorRef<GeneralizedLvalue> {
98	Expression * postmutate( AddressExpr * addressExpr );
99	Expression * postmutate( MemberExpr * memExpr );
100
101	template<typename Func>
102	Expression * applyTransformation( Expression * expr, Expression * arg, Func mkExpr );
103	};
104
105	/// Removes redundant &/& pattern that this pass can generate
106	struct CollapseAddrDeref final {
107	Expression * postmutate( AddressExpr * addressExpr );
108	Expression * postmutate( ApplicationExpr * appExpr );
109	};
110
111	struct AddrRef final : public WithGuards, public WithVisitorRef<AddrRef>, public WithShortCircuiting {
112	void premutate( AddressExpr * addrExpr );
113	Expression * postmutate( AddressExpr * addrExpr );
114	void premutate( Expression * expr );
115	void premutate( ApplicationExpr * appExpr );
116	void premutate( SingleInit * init );
117
118	void handleNonAddr( Expression * );
119
120	bool first = true;
121	bool current = false;
122	int refDepth = 0;
123	bool addCast = false;
124	};
125	} // namespace
126
127	// Stored elsewhere (Lvalue2, initially false).
128	extern bool referencesEliminated;
129
130	void convertLvalue( std::list< Declaration* > & translationUnit ) {
131	PassVisitor<ReferenceConversions> refCvt;
132	PassVisitor<ReferenceTypeElimination> elim;
133	PassVisitor<GeneralizedLvalue> genLval;
134	PassVisitor<FixIntrinsicArgs> fixer;
135	PassVisitor<CollapseAddrDeref> collapser;
136	PassVisitor<AddrRef> addrRef;
137	PassVisitor<FixIntrinsicResult> intrinsicResults;
138	mutateAll( translationUnit, intrinsicResults );
139	mutateAll( translationUnit, addrRef );
140	mutateAll( translationUnit, refCvt );
141	mutateAll( translationUnit, fixer );
142	mutateAll( translationUnit, collapser );
143	mutateAll( translationUnit, genLval );
144	mutateAll( translationUnit, elim ); // last because other passes need reference types to work
145
146	// from this point forward, no other pass should create reference types.
147	referencesEliminated = true;
148	}
149
150	Expression * generalizedLvalue( Expression * expr ) {
151	PassVisitor<GeneralizedLvalue> genLval;
152	return expr->acceptMutator( genLval );
153	}
154
155	namespace {
156	// true for intrinsic function calls that return an lvalue in C
157	bool isIntrinsicReference( Expression * expr ) {
158	// known intrinsic-reference prelude functions
159	static std::set<std::string> lvalueFunctions = { "*?", "?[?]" };
160	if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) {
161	std::string fname = InitTweak::getFunctionName( untyped );
162	return lvalueFunctions.count(fname);
163	} else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
164	if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) {
165	return func->linkage == LinkageSpec::Intrinsic && lvalueFunctions.count(func->name);
166	}
167	}
168	return false;
169	}
170
171	Expression * FixIntrinsicResult::postmutate( ApplicationExpr * appExpr ) {
172	if ( skip != SkipInProgress && isIntrinsicReference( appExpr ) ) {
173	// eliminate reference types from intrinsic applications - now they return lvalues
174	ReferenceType * result = strict_dynamic_cast< ReferenceType * >( appExpr->result );
175	appExpr->result = result->base->clone();
176	if ( ! inIntrinsic ) {
177	// when not in an intrinsic function, add a cast to
178	// don't add cast when in an intrinsic function, since they already have the cast
179	Expression * ret = new CastExpr( appExpr, result );
180	std::swap( ret->env, appExpr->env );
181	return ret;
182	}
183	delete result;
184	}
185	return appExpr;
186	}
187
188	void FixIntrinsicResult::premutate( FunctionDecl * funcDecl ) {
189	GuardValue( inIntrinsic );
190	inIntrinsic = funcDecl->linkage == LinkageSpec::Intrinsic;
191	}
192
193	Expression * FixIntrinsicArgs::postmutate( ApplicationExpr * appExpr ) {
194	// intrinsic functions don't really take reference-typed parameters, so they require an implicit dereference on their arguments.
195	if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
196	FunctionType * ftype = GenPoly::getFunctionType( function->get_type() );
197	assertf( ftype, "Function declaration does not have function type." );
198	// can be of differing lengths only when function is variadic
199	assertf( ftype->parameters.size() == appExpr->args.size() \|\| ftype->isVarArgs, "ApplicationExpr args do not match formal parameter type." );
200
201
202	unsigned int i = 0;
203	const unsigned int end = ftype->parameters.size();
204
205	/// The for loop may eagerly dereference the iterators and fail on empty lists
206	if(i == end) { return appExpr; }
207	for ( auto p : unsafe_group_iterate( appExpr->args, ftype->parameters ) ) {
208	Expression *& arg = std::get<0>( p );
209	Type * formal = std::get<1>( p )->get_type();
210	PRINT(
211	std::cerr << "pair<0>: " << arg << std::endl;
212	std::cerr << " -- " << arg->result << std::endl;
213	std::cerr << "pair<1>: " << formal << std::endl;
214	)
215	if ( dynamic_cast<ReferenceType*>( formal ) ) {
216	PRINT(
217	std::cerr << "===formal is reference" << std::endl;
218	)
219	// TODO: it's likely that the second condition should be ... && ! isIntrinsicReference( arg ), but this requires investigation.
220
221	if ( function->linkage != LinkageSpec::Intrinsic && isIntrinsicReference( arg ) ) {
222	// needed for definition of prelude functions, etc.
223	// if argument is dereference or array subscript, the result isn't REALLY a reference, but non-intrinsic functions expect a reference: take address
224
225	// NOTE: previously, this condition fixed
226	// void f(int *&);
227	// int & x = ...;
228	// f(&x);
229	// But now this is taken care of by a reference cast added by AddrRef. Need to find a new
230	// example or remove this branch.
231
232	PRINT(
233	std::cerr << "===is intrinsic arg in non-intrinsic call - adding address" << std::endl;
234	)
235	arg = new AddressExpr( arg );
236	// } else if ( function->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getPointerBase( arg->result ) ) {
237	} else if ( function->linkage == LinkageSpec::Intrinsic && arg->result->referenceDepth() != 0 ) {
238	// argument is a 'real' reference, but function expects a C lvalue: add a dereference to the reference-typed argument
239	PRINT(
240	std::cerr << "===is non-intrinsic arg in intrinsic call - adding deref to arg" << std::endl;
241	)
242	Type * baseType = InitTweak::getPointerBase( arg->result );
243	assertf( baseType, "parameter is reference, arg must be pointer or reference: %s", toString( arg->result ).c_str() );
244	PointerType * ptrType = new PointerType( Type::Qualifiers(), baseType->clone() );
245	delete arg->result;
246	arg->result = ptrType;
247	arg = mkDeref( arg );
248	// assertf( arg->result->referenceDepth() == 0, "Reference types should have been eliminated from intrinsic function calls, but weren't: %s", toCString( arg->result ) );
249	}
250	}
251	++i;
252	if (i == end) break;
253	}
254	}
255	return appExpr;
256	}
257
258	// idea: &&&E: get outer &, inner &
259	// at inner &, record depth D of reference type of argument of &
260	// at outer &, add D derefs.
261	void AddrRef::handleNonAddr( Expression * ) {
262	// non-address-of: reset status variables:
263	// * current expr is NOT the first address-of expr in an address-of chain
264	// * next seen address-of expr IS the first in the chain.
265	GuardValue( current );
266	GuardValue( first );
267	current = false;
268	first = true;
269	}
270
271	void AddrRef::premutate( Expression * expr ) {
272	handleNonAddr( expr );
273	GuardValue( addCast );
274	addCast = false;
275	}
276
277	void AddrRef::premutate( AddressExpr * ) {
278	GuardValue( current );
279	GuardValue( first );
280	current = first; // is this the first address-of in the chain?
281	first = false; // from here out, no longer possible for next address-of to be first in chain
282	if ( current ) { // this is the outermost address-of in a chain
283	GuardValue( refDepth );
284	refDepth = 0; // set depth to 0 so that postmutate can find the innermost address-of easily
285	}
286	}
287
288	Expression * AddrRef::postmutate( AddressExpr * addrExpr ) {
289	PRINT( std::cerr << "addr ref at " << addrExpr << std::endl; )
290	if ( refDepth == 0 ) {
291	PRINT( std::cerr << "depth 0, get new depth..." << std::endl; )
292	// this is the innermost address-of in a chain, record depth D
293	if ( ! isIntrinsicReference( addrExpr->arg ) ) {
294	// try to avoid ?[?]
295	// 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.
296	refDepth = addrExpr->arg->result->referenceDepth();
297	PRINT( std::cerr << "arg not intrinsic reference, new depth is: " << refDepth << std::endl; )
298	} else {
299	assertf( false, "AddrRef : address-of should not have intrinsic reference argument: %s", toCString( addrExpr->arg ) );
300	}
301	}
302	if ( current ) { // this is the outermost address-of in a chain
303	PRINT( std::cerr << "current, depth is: " << refDepth << std::endl; )
304	Expression * ret = addrExpr;
305	while ( refDepth ) {
306	// add one dereference for each
307	ret = mkDeref( ret );
308	refDepth--;
309	}
310
311	// if addrExpr depth is 0, then the result is a pointer because the arg was depth 1 and not lvalue.
312	// This means the dereference result is not a reference, is lvalue, and one less pointer depth than
313	// the addrExpr. Thus the cast is meaningless.
314	// TODO: One thing to double check is whether it is possible for the types to differ outside of the single
315	// pointer level (i.e. can the base type of addrExpr differ from the type of addrExpr-arg?).
316	// If so then the cast might need to be added, conditional on a more sophisticated check.
317	if ( addCast && addrExpr->result->referenceDepth() != 0 ) {
318	PRINT( std::cerr << "adding cast to " << addrExpr->result << std::endl; )
319	return new CastExpr( ret, addrExpr->result->clone() );
320	}
321	return ret;
322	}
323	PRINT( std::cerr << "not current..." << std::endl; )
324	return addrExpr;
325	}
326
327	void AddrRef::premutate( ApplicationExpr * appExpr ) {
328	visit_children = false;
329	GuardValue( addCast );
330	handleNonAddr( appExpr );
331	for ( Expression *& arg : appExpr->args ) {
332	// each argument with address-of requires a cast
333	addCast = true;
334	arg = arg->acceptMutator( *visitor );
335	}
336	}
337
338	void AddrRef::premutate( SingleInit * ) {
339	GuardValue( addCast );
340	// each initialization context with address-of requires a cast
341	addCast = true;
342	}
343
344
345	Expression * ReferenceConversions::postmutate( AddressExpr * addrExpr ) {
346	// Inner expression may have been lvalue to reference conversion, which becomes an address expression.
347	// In this case, remove the outer address expression and return the argument.
348	// TODO: It's possible that this might catch too much and require a more sophisticated check.
349	return addrExpr;
350	}
351
352	Expression * ReferenceConversions::postmutate( CastExpr * castExpr ) {
353	// xxx - is it possible to convert directly between reference types with a different base? E.g.,
354	// int x;
355	// (double&)x;
356	// At the moment, I am working off of the assumption that this is illegal, thus the cast becomes redundant
357	// after this pass, so trash the cast altogether. If that changes, care must be taken to insert the correct
358	// pointer casts in the right places.
359
360	// Note: reference depth difference is the determining factor in what code is run, rather than whether something is
361	// reference type or not, since conversion still needs to occur when both types are references that differ in depth.
362
363	Type * destType = castExpr->result;
364	Type * srcType = castExpr->arg->result;
365	assertf( destType, "Cast to no type in: %s", toCString( castExpr ) );
366	assertf( srcType, "Cast from no type in: %s", toCString( castExpr ) );
367	int depth1 = destType->referenceDepth();
368	int depth2 = srcType->referenceDepth();
369	int diff = depth1 - depth2;
370
371	if ( diff > 0 && ! castExpr->arg->get_lvalue() ) {
372	// rvalue to reference conversion -- introduce temporary
373	// know that reference depth of cast argument is 0, need to introduce n temporaries for reference depth of n, e.g.
374	// (int &&&)3;
375	// becomes
376	// int __ref_tmp_0 = 3;
377	// int & __ref_tmp_1 = _&_ref_tmp_0;
378	// int && __ref_tmp_2 = &__ref_tmp_1;
379	// &__ref_tmp_2;
380	// the last & comes from the remaining reference conversion code
381	SemanticWarning( castExpr->arg->location, Warning::RvalueToReferenceConversion, toCString( castExpr->arg ) );
382
383	static UniqueName tempNamer( "__ref_tmp_" );
384	ObjectDecl * temp = ObjectDecl::newObject( tempNamer.newName(), castExpr->arg->result->clone(), new SingleInit( castExpr->arg ) );
385	PRINT( std::cerr << "made temp: " << temp << std::endl; )
386	stmtsToAddBefore.push_back( new DeclStmt( temp ) );
387	for ( int i = 0; i < depth1-1; i++ ) { // xxx - maybe this should be diff-1? check how this works with reference type for srcType
388	ObjectDecl * newTemp = ObjectDecl::newObject( tempNamer.newName(), new ReferenceType( Type::Qualifiers(), temp->type->clone() ), new SingleInit( new AddressExpr( new VariableExpr( temp ) ) ) );
389	PRINT( std::cerr << "made temp" << i << ": " << newTemp << std::endl; )
390	stmtsToAddBefore.push_back( new DeclStmt( newTemp ) );
391	temp = newTemp;
392	}
393	// update diff so that remaining code works out correctly
394	castExpr->arg = new VariableExpr( temp );
395	PRINT( std::cerr << "update cast to: " << castExpr << std::endl; )
396	srcType = castExpr->arg->result;
397	depth2 = srcType->referenceDepth();
398	diff = depth1 - depth2;
399	assert( diff == 1 );
400	}
401
402	// handle conversion between different depths
403	PRINT (
404	if ( depth1 \|\| depth2 ) {
405	std::cerr << "destType: " << destType << " / srcType: " << srcType << std::endl;
406	std::cerr << "depth: " << depth1 << " / " << depth2 << std::endl;
407	}
408	)
409	if ( diff > 0 ) {
410	// conversion to type with more depth (e.g. int & -> int &&): add address-of for each level of difference
411	Expression * ret = castExpr->arg;
412	for ( int i = 0; i < diff; ++i ) {
413	ret = new AddressExpr( ret );
414	}
415	if ( castExpr->arg->get_lvalue() && ! ResolvExpr::typesCompatible( srcType, strict_dynamic_cast<ReferenceType *>( destType )->base, SymTab::Indexer() ) ) {
416	// must keep cast if cast-to type is different from the actual type
417	castExpr->arg = ret;
418	return castExpr;
419	}
420	ret->env = castExpr->env;
421	delete ret->result;
422	ret->result = castExpr->result;
423	castExpr->env = nullptr;
424	castExpr->arg = nullptr;
425	castExpr->result = nullptr;
426	delete castExpr;
427	return ret;
428	} else if ( diff < 0 ) {
429	// conversion to type with less depth (e.g. int && -> int &): add dereferences for each level of difference
430	diff = -diff; // care only about magnitude now
431	Expression * ret = castExpr->arg;
432	for ( int i = 0; i < diff; ++i ) {
433	ret = mkDeref( ret );
434	// xxx - try removing one reference here? actually, looks like mkDeref already does this, so more closely look at the types generated.
435	}
436	if ( ! ResolvExpr::typesCompatibleIgnoreQualifiers( destType->stripReferences(), srcType->stripReferences(), SymTab::Indexer() ) ) {
437	// must keep cast if types are different
438	castExpr->arg = ret;
439	return castExpr;
440	}
441	ret->env = castExpr->env;
442	delete ret->result;
443	ret->result = castExpr->result;
444	assert( ret->get_lvalue() ); // ensure result is lvalue
445	castExpr->env = nullptr;
446	castExpr->arg = nullptr;
447	castExpr->result = nullptr;
448	delete castExpr;
449	return ret;
450	} else {
451	assert( diff == 0 );
452	// conversion between references of the same depth
453	if ( ResolvExpr::typesCompatible( castExpr->result, castExpr->arg->result, SymTab::Indexer() ) && castExpr->isGenerated ) {
454	// Remove useless generated casts
455	PRINT(
456	std::cerr << "types are compatible, removing cast: " << castExpr << std::endl;
457	std::cerr << "-- " << castExpr->result << std::endl;
458	std::cerr << "-- " << castExpr->arg->result << std::endl;
459	)
460	Expression * ret = castExpr->arg;
461	castExpr->arg = nullptr;
462	std::swap( castExpr->env, ret->env );
463	delete castExpr;
464	return ret;
465	}
466	return castExpr;
467	}
468	}
469
470	Type * ReferenceTypeElimination::postmutate( ReferenceType * refType ) {
471	Type * base = refType->base;
472	Type::Qualifiers qualifiers = refType->get_qualifiers();
473	refType->base = nullptr;
474	delete refType;
475	return new PointerType( qualifiers, base );
476	}
477
478	template<typename Func>
479	Expression * GeneralizedLvalue::applyTransformation( Expression * expr, Expression * arg, Func mkExpr ) {
480	if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( arg ) ) {
481	Expression * arg1 = commaExpr->arg1->clone();
482	Expression * arg2 = commaExpr->arg2->clone();
483	Expression * ret = new CommaExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ) );
484	ret->env = expr->env;
485	expr->env = nullptr;
486	delete expr;
487	return ret;
488	} else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( arg ) ) {
489	Expression * arg1 = condExpr->arg1->clone();
490	Expression * arg2 = condExpr->arg2->clone();
491	Expression * arg3 = condExpr->arg3->clone();
492	ConditionalExpr * ret = new ConditionalExpr( arg1, mkExpr( arg2 )->acceptMutator( visitor ), mkExpr( arg3 )->acceptMutator( visitor ) );
493	ret->env = expr->env;
494	expr->env = nullptr;
495	delete expr;
496
497	// conditional expr type may not be either of the argument types, need to unify
498	using namespace ResolvExpr;
499	Type* commonType = nullptr;
500	TypeEnvironment newEnv;
501	AssertionSet needAssertions, haveAssertions;
502	OpenVarSet openVars;
503	unify( ret->arg2->result, ret->arg3->result, newEnv, needAssertions, haveAssertions, openVars, SymTab::Indexer(), commonType );
504	ret->result = commonType ? commonType : ret->arg2->result->clone();
505	return ret;
506	}
507	return expr;
508	}
509
510	Expression * GeneralizedLvalue::postmutate( MemberExpr * memExpr ) {
511	return applyTransformation( memExpr, memExpr->aggregate, [=]( Expression * aggr ) { return new MemberExpr( memExpr->member, aggr ); } );
512	}
513
514	Expression * GeneralizedLvalue::postmutate( AddressExpr * addrExpr ) {
515	return applyTransformation( addrExpr, addrExpr->arg, []( Expression * arg ) { return new AddressExpr( arg ); } );
516	}
517
518	Expression * CollapseAddrDeref::postmutate( AddressExpr * addrExpr ) {
519	Expression * arg = addrExpr->arg;
520	if ( isIntrinsicReference( arg ) ) {
521	std::string fname = InitTweak::getFunctionName( arg );
522	if ( fname == "*?" ) {
523	Expression *& arg0 = InitTweak::getCallArg( arg, 0 );
524	Expression * ret = arg0;
525	ret->set_env( addrExpr->env );
526	arg0 = nullptr;
527	addrExpr->env = nullptr;
528	delete addrExpr;
529	return ret;
530	}
531	} else if ( CastExpr * castExpr = dynamic_cast< CastExpr * > ( arg ) ) {
532	// need to move cast to pointer type out a level since address of pointer
533	// is not valid C code (can be introduced in prior passes, e.g., InstantiateGeneric)
534	if ( InitTweak::getPointerBase( castExpr->result ) ) {
535	addrExpr->arg = castExpr->arg;
536	castExpr->arg = addrExpr;
537	castExpr->result = new PointerType( Type::Qualifiers(), castExpr->result );
538	return castExpr;
539	}
540	}
541	return addrExpr;
542	}
543
544	Expression * CollapseAddrDeref::postmutate( ApplicationExpr * appExpr ) {
545	if ( isIntrinsicReference( appExpr ) ) {
546	std::string fname = InitTweak::getFunctionName( appExpr );
547	if ( fname == "*?" ) {
548	Expression * arg = InitTweak::getCallArg( appExpr, 0 );
549	// xxx - this isn't right, because it can remove casts that should be there...
550	// while ( CastExpr * castExpr = dynamic_cast< CastExpr * >( arg ) ) {
551	// arg = castExpr->get_arg();
552	// }
553	if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( arg ) ) {
554	Expression * ret = addrExpr->arg;
555	ret->env = appExpr->env;
556	addrExpr->arg = nullptr;
557	appExpr->env = nullptr;
558	delete appExpr;
559	return ret;
560	}
561	}
562	}
563	return appExpr;
564	}
565	} // namespace
566	} // namespace GenPoly
567
568	// Local Variables: //
569	// tab-width: 4 //
570	// mode: c++ //
571	// compile-command: "make install" //
572	// End: //

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