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source: src/GenPoly/Lvalue.cc @ 807a632

ADTarm-ehast-experimentalenumforall-pointer-decayjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprpthread-emulationqualifiedEnum

Last change on this file since 807a632 was b4f8808, checked in by Andrew Beach <ajbeach@…>, 5 years ago
Removed lvalue from types in the old ast.
Property mode set to `100644`
File size: 23.2 KB

Line
1	//
2	// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3	//
4	// The contents of this file are covered under the licence agreement in the
5	// file "LICENCE" distributed with Cforall.
6	//
7	// Lvalue.cc --
8	//
9	// Author : Richard C. Bilson
10	// Created On : Mon May 18 07:44:20 2015
11	// Last Modified By : Peter A. Buhr
12	// Last Modified On : Fri Mar 17 09:11:18 2017
13	// Update Count : 5
14	//
15
16	#include <cassert> // for strict_dynamic_cast
17	#include <string> // for string
18
19	#include "Common/PassVisitor.h"
20	#include "GenPoly.h" // for isPolyType
21	#include "Lvalue.h"
22
23	#include "InitTweak/InitTweak.h"
24	#include "Parser/LinkageSpec.h" // for Spec, isBuiltin, Intrinsic
25	#include "ResolvExpr/TypeEnvironment.h" // for AssertionSet, OpenVarSet
26	#include "ResolvExpr/Unify.h" // for unify
27	#include "ResolvExpr/typeops.h"
28	#include "SymTab/Indexer.h" // for Indexer
29	#include "SynTree/Declaration.h" // for Declaration, FunctionDecl
30	#include "SynTree/Expression.h" // for Expression, ConditionalExpr
31	#include "SynTree/Mutator.h" // for mutateAll, Mutator
32	#include "SynTree/Statement.h" // for ReturnStmt, Statement (ptr o...
33	#include "SynTree/Type.h" // for PointerType, Type, FunctionType
34	#include "SynTree/Visitor.h" // for Visitor, acceptAll
35	#include "Validate/FindSpecialDecls.h" // for dereferenceOperator
36
37	#if 0
38	#define PRINT(x) x
39	#else
40	#define PRINT(x)
41	#endif
42
43	namespace GenPoly {
44	namespace {
45	// TODO: fold this into the general createDeref function??
46	Expression * mkDeref( Expression * arg ) {
47	if ( Validate::dereferenceOperator ) {
48	// note: reference depth can be arbitrarily deep here, so peel off the outermost pointer/reference, not just pointer because they are effecitvely equivalent in this pass
49	VariableExpr * deref = new VariableExpr( Validate::dereferenceOperator );
50	deref->result = new PointerType( Type::Qualifiers(), deref->result );
51	Type * base = InitTweak::getPointerBase( arg->result );
52	assertf( base, "expected pointer type in dereference (type was %s)", toString( arg->result ).c_str() );
53	ApplicationExpr * ret = new ApplicationExpr( deref, { arg } );
54	delete ret->result;
55	ret->result = base->clone();
56	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	if ( ! inIntrinsic ) {
169	// when not in an intrinsic function, add a cast to
170	// don't add cast when in an intrinsic function, since they already have the cast
171	Expression * ret = new CastExpr( appExpr, result );
172	std::swap( ret->env, appExpr->env );
173	return ret;
174	}
175	delete result;
176	}
177	return appExpr;
178	}
179
180	void FixIntrinsicResult::premutate( FunctionDecl * funcDecl ) {
181	GuardValue( inIntrinsic );
182	inIntrinsic = funcDecl->linkage == LinkageSpec::Intrinsic;
183	}
184
185	Expression * FixIntrinsicArgs::postmutate( ApplicationExpr * appExpr ) {
186	// intrinsic functions don't really take reference-typed parameters, so they require an implicit dereference on their arguments.
187	if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
188	FunctionType * ftype = GenPoly::getFunctionType( function->get_type() );
189	assertf( ftype, "Function declaration does not have function type." );
190	// can be of differing lengths only when function is variadic
191	assertf( ftype->parameters.size() == appExpr->args.size() \|\| ftype->isVarArgs, "ApplicationExpr args do not match formal parameter type." );
192
193
194	unsigned int i = 0;
195	const unsigned int end = ftype->parameters.size();
196
197	/// The for loop may eagerly dereference the iterators and fail on empty lists
198	if(i == end) { return appExpr; }
199	for ( auto p : unsafe_group_iterate( appExpr->args, ftype->parameters ) ) {
200	Expression *& arg = std::get<0>( p );
201	Type * formal = std::get<1>( p )->get_type();
202	PRINT(
203	std::cerr << "pair<0>: " << arg << std::endl;
204	std::cerr << " -- " << arg->result << std::endl;
205	std::cerr << "pair<1>: " << formal << std::endl;
206	)
207	if ( dynamic_cast<ReferenceType*>( formal ) ) {
208	PRINT(
209	std::cerr << "===formal is reference" << std::endl;
210	)
211	// TODO: it's likely that the second condition should be ... && ! isIntrinsicReference( arg ), but this requires investigation.
212
213	if ( function->linkage != LinkageSpec::Intrinsic && isIntrinsicReference( arg ) ) {
214	// needed for definition of prelude functions, etc.
215	// if argument is dereference or array subscript, the result isn't REALLY a reference, but non-intrinsic functions expect a reference: take address
216
217	// NOTE: previously, this condition fixed
218	// void f(int *&);
219	// int & x = ...;
220	// f(&x);
221	// But now this is taken care of by a reference cast added by AddrRef. Need to find a new
222	// example or remove this branch.
223
224	PRINT(
225	std::cerr << "===is intrinsic arg in non-intrinsic call - adding address" << std::endl;
226	)
227	arg = new AddressExpr( arg );
228	// } else if ( function->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getPointerBase( arg->result ) ) {
229	} else if ( function->linkage == LinkageSpec::Intrinsic && arg->result->referenceDepth() != 0 ) {
230	// argument is a 'real' reference, but function expects a C lvalue: add a dereference to the reference-typed argument
231	PRINT(
232	std::cerr << "===is non-intrinsic arg in intrinsic call - adding deref to arg" << std::endl;
233	)
234	Type * baseType = InitTweak::getPointerBase( arg->result );
235	assertf( baseType, "parameter is reference, arg must be pointer or reference: %s", toString( arg->result ).c_str() );
236	PointerType * ptrType = new PointerType( Type::Qualifiers(), baseType->clone() );
237	delete arg->result;
238	arg->result = ptrType;
239	arg = mkDeref( arg );
240	// assertf( arg->result->referenceDepth() == 0, "Reference types should have been eliminated from intrinsic function calls, but weren't: %s", toCString( arg->result ) );
241	}
242	}
243	++i;
244	if (i == end) break;
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	assertf( destType, "Cast to no type in: %s", toCString( castExpr ) );
358	assertf( srcType, "Cast from no type in: %s", toCString( castExpr ) );
359	int depth1 = destType->referenceDepth();
360	int depth2 = srcType->referenceDepth();
361	int diff = depth1 - depth2;
362
363	if ( diff > 0 && ! castExpr->arg->get_lvalue() ) {
364	// rvalue to reference conversion -- introduce temporary
365	// know that reference depth of cast argument is 0, need to introduce n temporaries for reference depth of n, e.g.
366	// (int &&&)3;
367	// becomes
368	// int __ref_tmp_0 = 3;
369	// int & __ref_tmp_1 = _&_ref_tmp_0;
370	// int && __ref_tmp_2 = &__ref_tmp_1;
371	// &__ref_tmp_2;
372	// the last & comes from the remaining reference conversion code
373	SemanticWarning( castExpr->arg->location, Warning::RvalueToReferenceConversion, toCString( castExpr->arg ) );
374
375	static UniqueName tempNamer( "__ref_tmp_" );
376	ObjectDecl * temp = ObjectDecl::newObject( tempNamer.newName(), castExpr->arg->result->clone(), new SingleInit( castExpr->arg ) );
377	PRINT( std::cerr << "made temp: " << temp << std::endl; )
378	stmtsToAddBefore.push_back( new DeclStmt( temp ) );
379	for ( int i = 0; i < depth1-1; i++ ) { // xxx - maybe this should be diff-1? check how this works with reference type for srcType
380	ObjectDecl * newTemp = ObjectDecl::newObject( tempNamer.newName(), new ReferenceType( Type::Qualifiers(), temp->type->clone() ), new SingleInit( new AddressExpr( new VariableExpr( temp ) ) ) );
381	PRINT( std::cerr << "made temp" << i << ": " << newTemp << std::endl; )
382	stmtsToAddBefore.push_back( new DeclStmt( newTemp ) );
383	temp = newTemp;
384	}
385	// update diff so that remaining code works out correctly
386	castExpr->arg = new VariableExpr( temp );
387	PRINT( std::cerr << "update cast to: " << castExpr << std::endl; )
388	srcType = castExpr->arg->result;
389	depth2 = srcType->referenceDepth();
390	diff = depth1 - depth2;
391	assert( diff == 1 );
392	}
393
394	// handle conversion between different depths
395	PRINT (
396	if ( depth1 \|\| depth2 ) {
397	std::cerr << "destType: " << destType << " / srcType: " << srcType << std::endl;
398	std::cerr << "depth: " << depth1 << " / " << depth2 << std::endl;
399	}
400	)
401	if ( diff > 0 ) {
402	// conversion to type with more depth (e.g. int & -> int &&): add address-of for each level of difference
403	Expression * ret = castExpr->arg;
404	for ( int i = 0; i < diff; ++i ) {
405	ret = new AddressExpr( ret );
406	}
407	if ( castExpr->arg->get_lvalue() && ! ResolvExpr::typesCompatible( srcType, strict_dynamic_cast<ReferenceType *>( destType )->base, SymTab::Indexer() ) ) {
408	// must keep cast if cast-to type is different from the actual type
409	castExpr->arg = ret;
410	return castExpr;
411	}
412	ret->env = castExpr->env;
413	delete ret->result;
414	ret->result = castExpr->result;
415	castExpr->env = nullptr;
416	castExpr->arg = nullptr;
417	castExpr->result = nullptr;
418	delete castExpr;
419	return ret;
420	} else if ( diff < 0 ) {
421	// conversion to type with less depth (e.g. int && -> int &): add dereferences for each level of difference
422	diff = -diff; // care only about magnitude now
423	Expression * ret = castExpr->arg;
424	for ( int i = 0; i < diff; ++i ) {
425	ret = mkDeref( ret );
426	// xxx - try removing one reference here? actually, looks like mkDeref already does this, so more closely look at the types generated.
427	}
428	if ( ! ResolvExpr::typesCompatibleIgnoreQualifiers( destType->stripReferences(), srcType->stripReferences(), SymTab::Indexer() ) ) {
429	// must keep cast if types are different
430	castExpr->arg = ret;
431	return castExpr;
432	}
433	ret->env = castExpr->env;
434	delete ret->result;
435	ret->result = castExpr->result;
436	assert( ret->get_lvalue() ); // ensure result is lvalue
437	castExpr->env = nullptr;
438	castExpr->arg = nullptr;
439	castExpr->result = nullptr;
440	delete castExpr;
441	return ret;
442	} else {
443	assert( diff == 0 );
444	// conversion between references of the same depth
445	if ( ResolvExpr::typesCompatible( castExpr->result, castExpr->arg->result, SymTab::Indexer() ) && castExpr->isGenerated ) {
446	// Remove useless generated casts
447	PRINT(
448	std::cerr << "types are compatible, removing cast: " << castExpr << std::endl;
449	std::cerr << "-- " << castExpr->result << std::endl;
450	std::cerr << "-- " << castExpr->arg->result << std::endl;
451	)
452	Expression * ret = castExpr->arg;
453	castExpr->arg = nullptr;
454	std::swap( castExpr->env, ret->env );
455	delete castExpr;
456	return ret;
457	}
458	return castExpr;
459	}
460	}
461
462	Type * ReferenceTypeElimination::postmutate( ReferenceType * refType ) {
463	Type * base = refType->base;
464	Type::Qualifiers qualifiers = refType->get_qualifiers();
465	refType->base = nullptr;
466	delete refType;
467	return new PointerType( qualifiers, base );
468	}
469
470	template<typename Func>
471	Expression * GeneralizedLvalue::applyTransformation( Expression * expr, Expression * arg, Func mkExpr ) {
472	if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( arg ) ) {
473	Expression * arg1 = commaExpr->arg1->clone();
474	Expression * arg2 = commaExpr->arg2->clone();
475	Expression * ret = new CommaExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ) );
476	ret->env = expr->env;
477	expr->env = nullptr;
478	delete expr;
479	return ret;
480	} else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( arg ) ) {
481	Expression * arg1 = condExpr->arg1->clone();
482	Expression * arg2 = condExpr->arg2->clone();
483	Expression * arg3 = condExpr->arg3->clone();
484	ConditionalExpr * ret = new ConditionalExpr( arg1, mkExpr( arg2 )->acceptMutator( visitor ), mkExpr( arg3 )->acceptMutator( visitor ) );
485	ret->env = expr->env;
486	expr->env = nullptr;
487	delete expr;
488
489	// conditional expr type may not be either of the argument types, need to unify
490	using namespace ResolvExpr;
491	Type* commonType = nullptr;
492	TypeEnvironment newEnv;
493	AssertionSet needAssertions, haveAssertions;
494	OpenVarSet openVars;
495	unify( ret->arg2->result, ret->arg3->result, newEnv, needAssertions, haveAssertions, openVars, SymTab::Indexer(), commonType );
496	ret->result = commonType ? commonType : ret->arg2->result->clone();
497	return ret;
498	}
499	return expr;
500	}
501
502	Expression * GeneralizedLvalue::postmutate( MemberExpr * memExpr ) {
503	return applyTransformation( memExpr, memExpr->aggregate, [=]( Expression * aggr ) { return new MemberExpr( memExpr->member, aggr ); } );
504	}
505
506	Expression * GeneralizedLvalue::postmutate( AddressExpr * addrExpr ) {
507	return applyTransformation( addrExpr, addrExpr->arg, []( Expression * arg ) { return new AddressExpr( arg ); } );
508	}
509
510	Expression * CollapseAddrDeref::postmutate( AddressExpr * addrExpr ) {
511	Expression * arg = addrExpr->arg;
512	if ( isIntrinsicReference( arg ) ) {
513	std::string fname = InitTweak::getFunctionName( arg );
514	if ( fname == "*?" ) {
515	Expression *& arg0 = InitTweak::getCallArg( arg, 0 );
516	Expression * ret = arg0;
517	ret->set_env( addrExpr->env );
518	arg0 = nullptr;
519	addrExpr->env = nullptr;
520	delete addrExpr;
521	return ret;
522	}
523	} else if ( CastExpr * castExpr = dynamic_cast< CastExpr * > ( arg ) ) {
524	// need to move cast to pointer type out a level since address of pointer
525	// is not valid C code (can be introduced in prior passes, e.g., InstantiateGeneric)
526	if ( InitTweak::getPointerBase( castExpr->result ) ) {
527	addrExpr->arg = castExpr->arg;
528	castExpr->arg = addrExpr;
529	castExpr->result = new PointerType( Type::Qualifiers(), castExpr->result );
530	return castExpr;
531	}
532	}
533	return addrExpr;
534	}
535
536	Expression * CollapseAddrDeref::postmutate( ApplicationExpr * appExpr ) {
537	if ( isIntrinsicReference( appExpr ) ) {
538	std::string fname = InitTweak::getFunctionName( appExpr );
539	if ( fname == "*?" ) {
540	Expression * arg = InitTweak::getCallArg( appExpr, 0 );
541	// xxx - this isn't right, because it can remove casts that should be there...
542	// while ( CastExpr * castExpr = dynamic_cast< CastExpr * >( arg ) ) {
543	// arg = castExpr->get_arg();
544	// }
545	if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( arg ) ) {
546	Expression * ret = addrExpr->arg;
547	ret->env = appExpr->env;
548	addrExpr->arg = nullptr;
549	appExpr->env = nullptr;
550	delete appExpr;
551	return ret;
552	}
553	}
554	}
555	return appExpr;
556	}
557	} // namespace
558	} // namespace GenPoly
559
560	// Local Variables: //
561	// tab-width: 4 //
562	// mode: c++ //
563	// compile-command: "make install" //
564	// End: //

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