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source: src/ResolvExpr/AlternativeFinder.cc @ ac911f4

ADTaaron-thesisarm-ehast-experimentalcleanup-dtorsctordeferred_resndemanglerenumforall-pointer-decayjacob/cs343-translationjenkins-sandboxmemorynew-astnew-ast-unique-exprnew-envno_listpersistent-indexerpthread-emulationqualifiedEnumresolv-newwith_gc

Last change on this file since ac911f4 was 8e9cbb2, checked in by Peter A. Buhr <pabuhr@…>, 8 years ago
add more code to handle gcc extension and test program, second attempt
Property mode set to `100644`
File size: 42.2 KB

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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	// AlternativeFinder.cc --
8	//
9	// Author : Richard C. Bilson
10	// Created On : Sat May 16 23:52:08 2015
11	// Last Modified By : Peter A. Buhr
12	// Last Modified On : Mon Jul 4 17:02:51 2016
13	// Update Count : 29
14	//
15
16	#include <list>
17	#include <iterator>
18	#include <algorithm>
19	#include <functional>
20	#include <cassert>
21	#include <unordered_map>
22	#include <utility>
23	#include <vector>
24
25	#include "AlternativeFinder.h"
26	#include "Alternative.h"
27	#include "Cost.h"
28	#include "typeops.h"
29	#include "Unify.h"
30	#include "RenameVars.h"
31	#include "SynTree/Type.h"
32	#include "SynTree/Declaration.h"
33	#include "SynTree/Expression.h"
34	#include "SynTree/Initializer.h"
35	#include "SynTree/Visitor.h"
36	#include "SymTab/Indexer.h"
37	#include "SymTab/Mangler.h"
38	#include "SynTree/TypeSubstitution.h"
39	#include "SymTab/Validate.h"
40	#include "Designators/Processor.h"
41	#include "Tuples/TupleAssignment.h"
42	#include "Tuples/NameMatcher.h"
43	#include "Common/utility.h"
44	#include "InitTweak/InitTweak.h"
45
46	extern bool resolvep;
47	#define PRINT( text ) if ( resolvep ) { text }
48	//#define DEBUG_COST
49
50	namespace ResolvExpr {
51	Expression resolveInVoidContext( Expression expr, const SymTab::Indexer &indexer, TypeEnvironment &env ) {
52	CastExpr *castToVoid = new CastExpr( expr );
53
54	AlternativeFinder finder( indexer, env );
55	finder.findWithAdjustment( castToVoid );
56
57	// it's a property of the language that a cast expression has either 1 or 0 interpretations; if it has 0
58	// interpretations, an exception has already been thrown.
59	assert( finder.get_alternatives().size() == 1 );
60	CastExpr newExpr = dynamic_cast< CastExpr >( finder.get_alternatives().front().expr );
61	assert( newExpr );
62	env = finder.get_alternatives().front().env;
63	return newExpr->get_arg()->clone();
64	}
65
66	namespace {
67	void printAlts( const AltList &list, std::ostream &os, int indent = 0 ) {
68	for ( AltList::const_iterator i = list.begin(); i != list.end(); ++i ) {
69	i->print( os, indent );
70	os << std::endl;
71	}
72	}
73
74	void makeExprList( const AltList &in, std::list< Expression* > &out ) {
75	for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
76	out.push_back( i->expr->clone() );
77	}
78	}
79
80	Cost sumCost( const AltList &in ) {
81	Cost total;
82	for ( AltList::const_iterator i = in.begin(); i != in.end(); ++i ) {
83	total += i->cost;
84	}
85	return total;
86	}
87
88	struct PruneStruct {
89	bool isAmbiguous;
90	AltList::iterator candidate;
91	PruneStruct() {}
92	PruneStruct( AltList::iterator candidate ): isAmbiguous( false ), candidate( candidate ) {}
93	};
94
95	/// Prunes a list of alternatives down to those that have the minimum conversion cost for a given return type; skips ambiguous interpretations
96	template< typename InputIterator, typename OutputIterator >
97	void pruneAlternatives( InputIterator begin, InputIterator end, OutputIterator out, const SymTab::Indexer &indexer ) {
98	// select the alternatives that have the minimum conversion cost for a particular set of result types
99	std::map< std::string, PruneStruct > selected;
100	for ( AltList::iterator candidate = begin; candidate != end; ++candidate ) {
101	PruneStruct current( candidate );
102	std::string mangleName;
103	for ( std::list< Type* >::const_iterator retType = candidate->expr->get_results().begin(); retType != candidate->expr->get_results().end(); ++retType ) {
104	Type newType = (retType)->clone();
105	candidate->env.apply( newType );
106	mangleName += SymTab::Mangler::mangle( newType );
107	delete newType;
108	}
109	std::map< std::string, PruneStruct >::iterator mapPlace = selected.find( mangleName );
110	if ( mapPlace != selected.end() ) {
111	if ( candidate->cost < mapPlace->second.candidate->cost ) {
112	PRINT(
113	std::cerr << "cost " << candidate->cost << " beats " << mapPlace->second.candidate->cost << std::endl;
114	)
115	selected[ mangleName ] = current;
116	} else if ( candidate->cost == mapPlace->second.candidate->cost ) {
117	PRINT(
118	std::cerr << "marking ambiguous" << std::endl;
119	)
120	mapPlace->second.isAmbiguous = true;
121	}
122	} else {
123	selected[ mangleName ] = current;
124	}
125	}
126
127	PRINT(
128	std::cerr << "there are " << selected.size() << " alternatives before elimination" << std::endl;
129	)
130
131	// accept the alternatives that were unambiguous
132	for ( std::map< std::string, PruneStruct >::iterator target = selected.begin(); target != selected.end(); ++target ) {
133	if ( ! target->second.isAmbiguous ) {
134	Alternative &alt = *target->second.candidate;
135	for ( std::list< Type* >::iterator result = alt.expr->get_results().begin(); result != alt.expr->get_results().end(); ++result ) {
136	alt.env.applyFree( *result );
137	}
138	*out++ = alt;
139	}
140	}
141
142	}
143
144	template< typename InputIterator, typename OutputIterator >
145	void findMinCost( InputIterator begin, InputIterator end, OutputIterator out ) {
146	AltList alternatives;
147
148	// select the alternatives that have the minimum parameter cost
149	Cost minCost = Cost::infinity;
150	for ( AltList::iterator i = begin; i != end; ++i ) {
151	if ( i->cost < minCost ) {
152	minCost = i->cost;
153	i->cost = i->cvtCost;
154	alternatives.clear();
155	alternatives.push_back( *i );
156	} else if ( i->cost == minCost ) {
157	i->cost = i->cvtCost;
158	alternatives.push_back( *i );
159	}
160	}
161	std::copy( alternatives.begin(), alternatives.end(), out );
162	}
163
164	template< typename InputIterator >
165	void simpleCombineEnvironments( InputIterator begin, InputIterator end, TypeEnvironment &result ) {
166	while ( begin != end ) {
167	result.simpleCombine( (*begin++).env );
168	}
169	}
170
171	void renameTypes( Expression *expr ) {
172	for ( std::list< Type* >::iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
173	(*i)->accept( global_renamer );
174	}
175	}
176	}
177
178	template< typename InputIterator, typename OutputIterator >
179	void AlternativeFinder::findSubExprs( InputIterator begin, InputIterator end, OutputIterator out ) {
180	while ( begin != end ) {
181	AlternativeFinder finder( indexer, env );
182	finder.findWithAdjustment( *begin );
183	// XXX either this
184	//Designators::fixDesignations( finder, (*begin++)->get_argName() );
185	// or XXX this
186	begin++;
187	PRINT(
188	std::cerr << "findSubExprs" << std::endl;
189	printAlts( finder.alternatives, std::cerr );
190	)
191	*out++ = finder;
192	}
193	}
194
195	AlternativeFinder::AlternativeFinder( const SymTab::Indexer &indexer, const TypeEnvironment &env )
196	: indexer( indexer ), env( env ) {
197	}
198
199	void AlternativeFinder::find( Expression *expr, bool adjust ) {
200	expr->accept( *this );
201	if ( alternatives.empty() ) {
202	throw SemanticError( "No reasonable alternatives for expression ", expr );
203	}
204	for ( AltList::iterator i = alternatives.begin(); i != alternatives.end(); ++i ) {
205	if ( adjust ) {
206	adjustExprTypeList( i->expr->get_results().begin(), i->expr->get_results().end(), i->env, indexer );
207	}
208	}
209	PRINT(
210	std::cerr << "alternatives before prune:" << std::endl;
211	printAlts( alternatives, std::cerr );
212	)
213	AltList::iterator oldBegin = alternatives.begin();
214	pruneAlternatives( alternatives.begin(), alternatives.end(), front_inserter( alternatives ), indexer );
215	if ( alternatives.begin() == oldBegin ) {
216	std::ostringstream stream;
217	stream << "Can't choose between alternatives for expression ";
218	expr->print( stream );
219	stream << "Alternatives are:";
220	AltList winners;
221	findMinCost( alternatives.begin(), alternatives.end(), back_inserter( winners ) );
222	printAlts( winners, stream, 8 );
223	throw SemanticError( stream.str() );
224	}
225	alternatives.erase( oldBegin, alternatives.end() );
226	PRINT(
227	std::cerr << "there are " << alternatives.size() << " alternatives after elimination" << std::endl;
228	)
229
230	// Central location to handle gcc extension keyword for all expression types.
231	for ( Alternative &iter: alternatives ) {
232	iter.expr->set_extension( expr->get_extension() );
233	} // for
234	}
235
236	void AlternativeFinder::findWithAdjustment( Expression *expr ) {
237	find( expr, true );
238	}
239
240	template< typename StructOrUnionType >
241	void AlternativeFinder::addAggMembers( StructOrUnionType aggInst, Expression expr, const Cost &newCost, const std::string &name ) {
242	std::list< Declaration* > members;
243	aggInst->lookup( name, members );
244	for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
245	if ( DeclarationWithType dwt = dynamic_cast< DeclarationWithType >( *i ) ) {
246	alternatives.push_back( Alternative( new MemberExpr( dwt->clone(), expr->clone() ), env, newCost ) );
247	renameTypes( alternatives.back().expr );
248	} else {
249	assert( false );
250	}
251	}
252	}
253
254	void AlternativeFinder::visit( ApplicationExpr *applicationExpr ) {
255	alternatives.push_back( Alternative( applicationExpr->clone(), env, Cost::zero ) );
256	}
257
258	Cost computeConversionCost( Alternative &alt, const SymTab::Indexer &indexer ) {
259	ApplicationExpr appExpr = dynamic_cast< ApplicationExpr >( alt.expr );
260	assert( appExpr );
261	PointerType pointer = dynamic_cast< PointerType >( appExpr->get_function()->get_results().front() );
262	assert( pointer );
263	FunctionType function = dynamic_cast< FunctionType >( pointer->get_base() );
264	assert( function );
265
266	Cost convCost( 0, 0, 0 );
267	std::list< DeclarationWithType* >& formals = function->get_parameters();
268	std::list< DeclarationWithType* >::iterator formal = formals.begin();
269	std::list< Expression* >& actuals = appExpr->get_args();
270	for ( std::list< Expression* >::iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
271	PRINT(
272	std::cerr << "actual expression:" << std::endl;
273	(*actualExpr)->print( std::cerr, 8 );
274	std::cerr << "--- results are" << std::endl;
275	printAll( (*actualExpr)->get_results(), std::cerr, 8 );
276	)
277	std::list< DeclarationWithType* >::iterator startFormal = formal;
278	Cost actualCost;
279	for ( std::list< Type* >::iterator actual = (actualExpr)->get_results().begin(); actual != (actualExpr)->get_results().end(); ++actual ) {
280	if ( formal == formals.end() ) {
281	if ( function->get_isVarArgs() ) {
282	convCost += Cost( 1, 0, 0 );
283	break;
284	} else {
285	return Cost::infinity;
286	}
287	}
288	PRINT(
289	std::cerr << std::endl << "converting ";
290	(*actual)->print( std::cerr, 8 );
291	std::cerr << std::endl << " to ";
292	(*formal)->get_type()->print( std::cerr, 8 );
293	)
294	Cost newCost = conversionCost( actual, (formal)->get_type(), indexer, alt.env );
295	PRINT(
296	std::cerr << std::endl << "cost is" << newCost << std::endl;
297	)
298
299	if ( newCost == Cost::infinity ) {
300	return newCost;
301	}
302	convCost += newCost;
303	actualCost += newCost;
304
305	convCost += Cost( 0, polyCost( (formal)->get_type(), alt.env, indexer ) + polyCost( actual, alt.env, indexer ), 0 );
306
307	formal++;
308	}
309	if ( actualCost != Cost( 0, 0, 0 ) ) {
310	std::list< DeclarationWithType* >::iterator startFormalPlusOne = startFormal;
311	startFormalPlusOne++;
312	if ( formal == startFormalPlusOne ) {
313	// not a tuple type
314	Type newType = (startFormal)->get_type()->clone();
315	alt.env.apply( newType );
316	actualExpr = new CastExpr( actualExpr, newType );
317	} else {
318	TupleType *newType = new TupleType( Type::Qualifiers() );
319	for ( std::list< DeclarationWithType* >::iterator i = startFormal; i != formal; ++i ) {
320	newType->get_types().push_back( (*i)->get_type()->clone() );
321	}
322	alt.env.apply( newType );
323	actualExpr = new CastExpr( actualExpr, newType );
324	}
325	}
326
327	}
328	if ( formal != formals.end() ) {
329	return Cost::infinity;
330	}
331
332	for ( InferredParams::const_iterator assert = appExpr->get_inferParams().begin(); assert != appExpr->get_inferParams().end(); ++assert ) {
333	PRINT(
334	std::cerr << std::endl << "converting ";
335	assert->second.actualType->print( std::cerr, 8 );
336	std::cerr << std::endl << " to ";
337	assert->second.formalType->print( std::cerr, 8 );
338	)
339	Cost newCost = conversionCost( assert->second.actualType, assert->second.formalType, indexer, alt.env );
340	PRINT(
341	std::cerr << std::endl << "cost of conversion is " << newCost << std::endl;
342	)
343	if ( newCost == Cost::infinity ) {
344	return newCost;
345	}
346	convCost += newCost;
347
348	convCost += Cost( 0, polyCost( assert->second.formalType, alt.env, indexer ) + polyCost( assert->second.actualType, alt.env, indexer ), 0 );
349	}
350
351	return convCost;
352	}
353
354	/// Adds type variables to the open variable set and marks their assertions
355	void makeUnifiableVars( Type *type, OpenVarSet &unifiableVars, AssertionSet &needAssertions ) {
356	for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
357	unifiableVars[ (tyvar)->get_name() ] = (tyvar)->get_kind();
358	for ( std::list< DeclarationWithType* >::iterator assert = (tyvar)->get_assertions().begin(); assert != (tyvar)->get_assertions().end(); ++assert ) {
359	needAssertions[ *assert ] = true;
360	}
361	/// needAssertions.insert( needAssertions.end(), (tyvar)->get_assertions().begin(), (tyvar)->get_assertions().end() );
362	}
363	}
364
365	bool AlternativeFinder::instantiateFunction( std::list< DeclarationWithType* >& formals, /const/ AltList &actuals, bool isVarArgs, OpenVarSet& openVars, TypeEnvironment &resultEnv, AssertionSet &resultNeed, AssertionSet &resultHave ) {
366	simpleCombineEnvironments( actuals.begin(), actuals.end(), resultEnv );
367	// make sure we don't widen any existing bindings
368	for ( TypeEnvironment::iterator i = resultEnv.begin(); i != resultEnv.end(); ++i ) {
369	i->allowWidening = false;
370	}
371	resultEnv.extractOpenVars( openVars );
372
373	/*
374	Tuples::NameMatcher matcher( formals );
375	try {
376	matcher.match( actuals );
377	} catch ( Tuples::NoMatch &e ) {
378	std::cerr << "Alternative doesn't match: " << e.message << std::endl;
379	}
380	*/
381	std::list< DeclarationWithType* >::iterator formal = formals.begin();
382	for ( AltList::const_iterator actualExpr = actuals.begin(); actualExpr != actuals.end(); ++actualExpr ) {
383	for ( std::list< Type* >::iterator actual = actualExpr->expr->get_results().begin(); actual != actualExpr->expr->get_results().end(); ++actual ) {
384	if ( formal == formals.end() ) {
385	return isVarArgs;
386	}
387	PRINT(
388	std::cerr << "formal type is ";
389	(*formal)->get_type()->print( std::cerr );
390	std::cerr << std::endl << "actual type is ";
391	(*actual)->print( std::cerr );
392	std::cerr << std::endl;
393	)
394	if ( ! unify( (formal)->get_type(), actual, resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
395	return false;
396	}
397	formal++;
398	}
399	}
400	// Handling of default values
401	while ( formal != formals.end() ) {
402	if ( ObjectDecl od = dynamic_cast<ObjectDecl >( *formal ) )
403	if ( SingleInit si = dynamic_cast<SingleInit >( od->get_init() ))
404	// so far, only constant expressions are accepted as default values
405	if ( ConstantExpr cnstexpr = dynamic_cast<ConstantExpr >( si->get_value()) )
406	if ( Constant cnst = dynamic_cast<Constant >( cnstexpr->get_constant() ) )
407	if ( unify( (*formal)->get_type(), cnst->get_type(), resultEnv, resultNeed, resultHave, openVars, indexer ) ) {
408	// XXX Don't know if this is right
409	actuals.push_back( Alternative( cnstexpr->clone(), env, Cost::zero ) );
410	formal++;
411	if ( formal == formals.end()) break;
412	}
413	return false;
414	}
415	return true;
416	}
417
418	// /// Map of declaration uniqueIds (intended to be the assertions in an AssertionSet) to their parents and the number of times they've been included
419	//typedef std::unordered_map< UniqueId, std::unordered_map< UniqueId, unsigned > > AssertionParentSet;
420
421	static const int recursionLimit = /10/ 4; ///< Limit to depth of recursion satisfaction
422	//static const unsigned recursionParentLimit = 1; ///< Limit to the number of times an assertion can recursively use itself
423
424	void addToIndexer( AssertionSet &assertSet, SymTab::Indexer &indexer ) {
425	for ( AssertionSet::iterator i = assertSet.begin(); i != assertSet.end(); ++i ) {
426	if ( i->second == true ) {
427	i->first->accept( indexer );
428	}
429	}
430	}
431
432	template< typename ForwardIterator, typename OutputIterator >
433	void inferRecursive( ForwardIterator begin, ForwardIterator end, const Alternative &newAlt, OpenVarSet &openVars, const SymTab::Indexer &decls, const AssertionSet &newNeed, /const AssertionParentSet &needParents,/
434	int level, const SymTab::Indexer &indexer, OutputIterator out ) {
435	if ( begin == end ) {
436	if ( newNeed.empty() ) {
437	*out++ = newAlt;
438	return;
439	} else if ( level >= recursionLimit ) {
440	throw SemanticError( "Too many recursive assertions" );
441	} else {
442	AssertionSet newerNeed;
443	PRINT(
444	std::cerr << "recursing with new set:" << std::endl;
445	printAssertionSet( newNeed, std::cerr, 8 );
446	)
447	inferRecursive( newNeed.begin(), newNeed.end(), newAlt, openVars, decls, newerNeed, /needParents,/ level+1, indexer, out );
448	return;
449	}
450	}
451
452	ForwardIterator cur = begin++;
453	if ( ! cur->second ) {
454	inferRecursive( begin, end, newAlt, openVars, decls, newNeed, /needParents,/ level, indexer, out );
455	}
456	DeclarationWithType *curDecl = cur->first;
457	PRINT(
458	std::cerr << "inferRecursive: assertion is ";
459	curDecl->print( std::cerr );
460	std::cerr << std::endl;
461	)
462	std::list< DeclarationWithType* > candidates;
463	decls.lookupId( curDecl->get_name(), candidates );
464	/// if ( candidates.empty() ) { std::cerr << "no candidates!" << std::endl; }
465	for ( std::list< DeclarationWithType* >::const_iterator candidate = candidates.begin(); candidate != candidates.end(); ++candidate ) {
466	PRINT(
467	std::cerr << "inferRecursive: candidate is ";
468	(*candidate)->print( std::cerr );
469	std::cerr << std::endl;
470	)
471
472	AssertionSet newHave, newerNeed( newNeed );
473	TypeEnvironment newEnv( newAlt.env );
474	OpenVarSet newOpenVars( openVars );
475	Type adjType = (candidate)->get_type()->clone();
476	adjustExprType( adjType, newEnv, indexer );
477	adjType->accept( global_renamer );
478	PRINT(
479	std::cerr << "unifying ";
480	curDecl->get_type()->print( std::cerr );
481	std::cerr << " with ";
482	adjType->print( std::cerr );
483	std::cerr << std::endl;
484	)
485	if ( unify( curDecl->get_type(), adjType, newEnv, newerNeed, newHave, newOpenVars, indexer ) ) {
486	PRINT(
487	std::cerr << "success!" << std::endl;
488	)
489	SymTab::Indexer newDecls( decls );
490	addToIndexer( newHave, newDecls );
491	Alternative newerAlt( newAlt );
492	newerAlt.env = newEnv;
493	assert( (*candidate)->get_uniqueId() );
494	DeclarationWithType candDecl = static_cast< DeclarationWithType >( Declaration::declFromId( (*candidate)->get_uniqueId() ) );
495	//AssertionParentSet newNeedParents( needParents );
496	// skip repeatingly-self-recursive assertion satisfaction
497	// DOESN'T WORK: grandchild nodes conflict with their cousins
498	//if ( newNeedParents[ curDecl->get_uniqueId() ][ candDecl->get_uniqueId() ]++ > recursionParentLimit ) continue;
499	Expression *varExpr = new VariableExpr( candDecl );
500	deleteAll( varExpr->get_results() );
501	varExpr->get_results().clear();
502	varExpr->get_results().push_front( adjType->clone() );
503	PRINT(
504	std::cerr << "satisfying assertion " << curDecl->get_uniqueId() << " ";
505	curDecl->print( std::cerr );
506	std::cerr << " with declaration " << (*candidate)->get_uniqueId() << " ";
507	(*candidate)->print( std::cerr );
508	std::cerr << std::endl;
509	)
510	ApplicationExpr appExpr = static_cast< ApplicationExpr >( newerAlt.expr );
511	// XXX: this is a memory leak, but adjType can't be deleted because it might contain assertions
512	appExpr->get_inferParams()[ curDecl->get_uniqueId() ] = ParamEntry( (*candidate)->get_uniqueId(), adjType->clone(), curDecl->get_type()->clone(), varExpr );
513	inferRecursive( begin, end, newerAlt, newOpenVars, newDecls, newerNeed, /newNeedParents,/ level, indexer, out );
514	} else {
515	delete adjType;
516	}
517	}
518	}
519
520	template< typename OutputIterator >
521	void AlternativeFinder::inferParameters( const AssertionSet &need, AssertionSet &have, const Alternative &newAlt, OpenVarSet &openVars, OutputIterator out ) {
522	// PRINT(
523	// std::cerr << "inferParameters: assertions needed are" << std::endl;
524	// printAll( need, std::cerr, 8 );
525	// )
526	SymTab::Indexer decls( indexer );
527	PRINT(
528	std::cerr << "============= original indexer" << std::endl;
529	indexer.print( std::cerr );
530	std::cerr << "============= new indexer" << std::endl;
531	decls.print( std::cerr );
532	)
533	addToIndexer( have, decls );
534	AssertionSet newNeed;
535	//AssertionParentSet needParents;
536	inferRecursive( need.begin(), need.end(), newAlt, openVars, decls, newNeed, /needParents,/ 0, indexer, out );
537	// PRINT(
538	// std::cerr << "declaration 14 is ";
539	// Declaration::declFromId
540	// *out++ = newAlt;
541	// )
542	}
543
544	template< typename OutputIterator >
545	void AlternativeFinder::makeFunctionAlternatives( const Alternative &func, FunctionType *funcType, AltList &actualAlt, OutputIterator out ) {
546	OpenVarSet openVars;
547	AssertionSet resultNeed, resultHave;
548	TypeEnvironment resultEnv;
549	makeUnifiableVars( funcType, openVars, resultNeed );
550	if ( instantiateFunction( funcType->get_parameters(), actualAlt, funcType->get_isVarArgs(), openVars, resultEnv, resultNeed, resultHave ) ) {
551	ApplicationExpr *appExpr = new ApplicationExpr( func.expr->clone() );
552	Alternative newAlt( appExpr, resultEnv, sumCost( actualAlt ) );
553	makeExprList( actualAlt, appExpr->get_args() );
554	PRINT(
555	std::cerr << "need assertions:" << std::endl;
556	printAssertionSet( resultNeed, std::cerr, 8 );
557	)
558	inferParameters( resultNeed, resultHave, newAlt, openVars, out );
559	}
560	}
561
562	void AlternativeFinder::visit( UntypedExpr *untypedExpr ) {
563	bool doneInit = false;
564	AlternativeFinder funcOpFinder( indexer, env );
565
566	AlternativeFinder funcFinder( indexer, env );
567
568	{
569	std::string fname = InitTweak::getFunctionName( untypedExpr );
570	if ( fname == "&&" ) {
571	VoidType v = Type::Qualifiers(); // resolve to type void *
572	PointerType pt( Type::Qualifiers(), v.clone() );
573	UntypedExpr *vexpr = untypedExpr->clone();
574	vexpr->get_results().push_front( pt.clone() );
575	alternatives.push_back( Alternative( vexpr, env, Cost()) );
576	return;
577	}
578	}
579
580	funcFinder.findWithAdjustment( untypedExpr->get_function() );
581	std::list< AlternativeFinder > argAlternatives;
582	findSubExprs( untypedExpr->begin_args(), untypedExpr->end_args(), back_inserter( argAlternatives ) );
583
584	std::list< AltList > possibilities;
585	combos( argAlternatives.begin(), argAlternatives.end(), back_inserter( possibilities ) );
586
587	Tuples::TupleAssignSpotter tassign( this );
588	if ( tassign.isTupleAssignment( untypedExpr, possibilities ) ) {
589	// take care of possible tuple assignments, or discard expression
590	return;
591	} // else ...
592
593	AltList candidates;
594	SemanticError errors;
595
596	for ( AltList::const_iterator func = funcFinder.alternatives.begin(); func != funcFinder.alternatives.end(); ++func ) {
597	try {
598	PRINT(
599	std::cerr << "working on alternative: " << std::endl;
600	func->print( std::cerr, 8 );
601	)
602	// check if the type is pointer to function
603	PointerType *pointer;
604	if ( func->expr->get_results().size() == 1 && ( pointer = dynamic_cast< PointerType* >( func->expr->get_results().front() ) ) ) {
605	if ( FunctionType function = dynamic_cast< FunctionType >( pointer->get_base() ) ) {
606	for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
607	// XXX
608	//Designators::check_alternative( function, *actualAlt );
609	makeFunctionAlternatives( func, function, actualAlt, std::back_inserter( candidates ) );
610	}
611	} else if ( TypeInstType typeInst = dynamic_cast< TypeInstType >( pointer->get_base() ) ) {
612	EqvClass eqvClass;
613	if ( func->env.lookup( typeInst->get_name(), eqvClass ) && eqvClass.type ) {
614	if ( FunctionType function = dynamic_cast< FunctionType >( eqvClass.type ) ) {
615	for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
616	makeFunctionAlternatives( func, function, actualAlt, std::back_inserter( candidates ) );
617	} // for
618	} // if
619	} // if
620	} // if
621	} else {
622	// seek a function operator that's compatible
623	if ( ! doneInit ) {
624	doneInit = true;
625	NameExpr *opExpr = new NameExpr( "?()" );
626	try {
627	funcOpFinder.findWithAdjustment( opExpr );
628	} catch( SemanticError &e ) {
629	// it's ok if there aren't any defined function ops
630	}
631	PRINT(
632	std::cerr << "known function ops:" << std::endl;
633	printAlts( funcOpFinder.alternatives, std::cerr, 8 );
634	)
635	}
636
637	for ( AltList::const_iterator funcOp = funcOpFinder.alternatives.begin(); funcOp != funcOpFinder.alternatives.end(); ++funcOp ) {
638	// check if the type is pointer to function
639	PointerType *pointer;
640	if ( funcOp->expr->get_results().size() == 1
641	&& ( pointer = dynamic_cast< PointerType* >( funcOp->expr->get_results().front() ) ) ) {
642	if ( FunctionType function = dynamic_cast< FunctionType >( pointer->get_base() ) ) {
643	for ( std::list< AltList >::iterator actualAlt = possibilities.begin(); actualAlt != possibilities.end(); ++actualAlt ) {
644	AltList currentAlt;
645	currentAlt.push_back( *func );
646	currentAlt.insert( currentAlt.end(), actualAlt->begin(), actualAlt->end() );
647	makeFunctionAlternatives( *funcOp, function, currentAlt, std::back_inserter( candidates ) );
648	} // for
649	} // if
650	} // if
651	} // for
652	} // if
653	} catch ( SemanticError &e ) {
654	errors.append( e );
655	}
656	} // for
657
658	// Implement SFINAE; resolution errors are only errors if there aren't any non-erroneous resolutions
659	if ( candidates.empty() && ! errors.isEmpty() ) { throw errors; }
660
661	for ( AltList::iterator withFunc = candidates.begin(); withFunc != candidates.end(); ++withFunc ) {
662	Cost cvtCost = computeConversionCost( *withFunc, indexer );
663
664	PRINT(
665	ApplicationExpr appExpr = dynamic_cast< ApplicationExpr >( withFunc->expr );
666	assert( appExpr );
667	PointerType pointer = dynamic_cast< PointerType >( appExpr->get_function()->get_results().front() );
668	assert( pointer );
669	FunctionType function = dynamic_cast< FunctionType >( pointer->get_base() );
670	assert( function );
671	std::cerr << "Case +++++++++++++" << std::endl;
672	std::cerr << "formals are:" << std::endl;
673	printAll( function->get_parameters(), std::cerr, 8 );
674	std::cerr << "actuals are:" << std::endl;
675	printAll( appExpr->get_args(), std::cerr, 8 );
676	std::cerr << "bindings are:" << std::endl;
677	withFunc->env.print( std::cerr, 8 );
678	std::cerr << "cost of conversion is:" << cvtCost << std::endl;
679	)
680	if ( cvtCost != Cost::infinity ) {
681	withFunc->cvtCost = cvtCost;
682	alternatives.push_back( *withFunc );
683	} // if
684	} // for
685	candidates.clear();
686	candidates.splice( candidates.end(), alternatives );
687
688	findMinCost( candidates.begin(), candidates.end(), std::back_inserter( alternatives ) );
689	}
690
691	bool isLvalue( Expression *expr ) {
692	for ( std::list< Type* >::const_iterator i = expr->get_results().begin(); i != expr->get_results().end(); ++i ) {
693	if ( !(*i)->get_isLvalue() ) return false;
694	} // for
695	return true;
696	}
697
698	void AlternativeFinder::visit( AddressExpr *addressExpr ) {
699	AlternativeFinder finder( indexer, env );
700	finder.find( addressExpr->get_arg() );
701	for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
702	if ( isLvalue( i->expr ) ) {
703	alternatives.push_back( Alternative( new AddressExpr( i->expr->clone() ), i->env, i->cost ) );
704	} // if
705	} // for
706	}
707
708	void AlternativeFinder::visit( CastExpr *castExpr ) {
709	for ( std::list< Type* >::iterator i = castExpr->get_results().begin(); i != castExpr->get_results().end(); ++i ) {
710	SymTab::validateType( *i, &indexer );
711	adjustExprType( *i, env, indexer );
712	} // for
713
714	AlternativeFinder finder( indexer, env );
715	finder.findWithAdjustment( castExpr->get_arg() );
716
717	AltList candidates;
718	for ( std::list< Alternative >::iterator i = finder.alternatives.begin(); i != finder.alternatives.end(); ++i ) {
719	AssertionSet needAssertions, haveAssertions;
720	OpenVarSet openVars;
721
722	// It's possible that a cast can throw away some values in a multiply-valued expression. (An example is a
723	// cast-to-void, which casts from one value to zero.) Figure out the prefix of the subexpression results
724	// that are cast directly. The candidate is invalid if it has fewer results than there are types to cast
725	// to.
726	int discardedValues = (*i).expr->get_results().size() - castExpr->get_results().size();
727	if ( discardedValues < 0 ) continue;
728	std::list< Type* >::iterator candidate_end = (*i).expr->get_results().begin();
729	std::advance( candidate_end, castExpr->get_results().size() );
730	// unification run for side-effects
731	unifyList( castExpr->get_results().begin(), castExpr->get_results().end(),
732	(*i).expr->get_results().begin(), candidate_end,
733	i->env, needAssertions, haveAssertions, openVars, indexer );
734	Cost thisCost = castCostList( (*i).expr->get_results().begin(), candidate_end,
735	castExpr->get_results().begin(), castExpr->get_results().end(),
736	indexer, i->env );
737	if ( thisCost != Cost::infinity ) {
738	// count one safe conversion for each value that is thrown away
739	thisCost += Cost( 0, 0, discardedValues );
740	CastExpr *newExpr = castExpr->clone();
741	newExpr->set_arg( i->expr->clone() );
742	candidates.push_back( Alternative( newExpr, i->env, i->cost, thisCost ) );
743	} // if
744	} // for
745
746	// findMinCost selects the alternatives with the lowest "cost" members, but has the side effect of copying the
747	// cvtCost member to the cost member (since the old cost is now irrelevant). Thus, calling findMinCost twice
748	// selects first based on argument cost, then on conversion cost.
749	AltList minArgCost;
750	findMinCost( candidates.begin(), candidates.end(), std::back_inserter( minArgCost ) );
751	findMinCost( minArgCost.begin(), minArgCost.end(), std::back_inserter( alternatives ) );
752	}
753
754	void AlternativeFinder::visit( UntypedMemberExpr *memberExpr ) {
755	AlternativeFinder funcFinder( indexer, env );
756	funcFinder.findWithAdjustment( memberExpr->get_aggregate() );
757
758	for ( AltList::const_iterator agg = funcFinder.alternatives.begin(); agg != funcFinder.alternatives.end(); ++agg ) {
759	if ( agg->expr->get_results().size() == 1 ) {
760	if ( StructInstType structInst = dynamic_cast< StructInstType >( agg->expr->get_results().front() ) ) {
761	addAggMembers( structInst, agg->expr, agg->cost, memberExpr->get_member() );
762	} else if ( UnionInstType unionInst = dynamic_cast< UnionInstType >( agg->expr->get_results().front() ) ) {
763	addAggMembers( unionInst, agg->expr, agg->cost, memberExpr->get_member() );
764	} // if
765	} // if
766	} // for
767	}
768
769	void AlternativeFinder::visit( MemberExpr *memberExpr ) {
770	alternatives.push_back( Alternative( memberExpr->clone(), env, Cost::zero ) );
771	}
772
773	void AlternativeFinder::visit( NameExpr *nameExpr ) {
774	std::list< DeclarationWithType* > declList;
775	indexer.lookupId( nameExpr->get_name(), declList );
776	PRINT( std::cerr << "nameExpr is " << nameExpr->get_name() << std::endl; )
777	for ( std::list< DeclarationWithType* >::iterator i = declList.begin(); i != declList.end(); ++i ) {
778	VariableExpr newExpr( *i, nameExpr->get_argName() );
779	alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
780	PRINT(
781	std::cerr << "decl is ";
782	(*i)->print( std::cerr );
783	std::cerr << std::endl;
784	std::cerr << "newExpr is ";
785	newExpr.print( std::cerr );
786	std::cerr << std::endl;
787	)
788	renameTypes( alternatives.back().expr );
789	if ( StructInstType structInst = dynamic_cast< StructInstType >( (*i)->get_type() ) ) {
790	addAggMembers( structInst, &newExpr, Cost( 0, 0, 1 ), "" );
791	} else if ( UnionInstType unionInst = dynamic_cast< UnionInstType >( (*i)->get_type() ) ) {
792	addAggMembers( unionInst, &newExpr, Cost( 0, 0, 1 ), "" );
793	} // if
794	} // for
795	}
796
797	void AlternativeFinder::visit( VariableExpr *variableExpr ) {
798	alternatives.push_back( Alternative( variableExpr->clone(), env, Cost::zero ) );
799	}
800
801	void AlternativeFinder::visit( ConstantExpr *constantExpr ) {
802	alternatives.push_back( Alternative( constantExpr->clone(), env, Cost::zero ) );
803	}
804
805	void AlternativeFinder::visit( SizeofExpr *sizeofExpr ) {
806	if ( sizeofExpr->get_isType() ) {
807	alternatives.push_back( Alternative( sizeofExpr->clone(), env, Cost::zero ) );
808	} else {
809	// find all alternatives for the argument to sizeof
810	AlternativeFinder finder( indexer, env );
811	finder.find( sizeofExpr->get_expr() );
812	// find the lowest cost alternative among the alternatives, otherwise ambiguous
813	AltList winners;
814	findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
815	if ( winners.size() != 1 ) {
816	throw SemanticError( "Ambiguous expression in sizeof operand: ", sizeofExpr->get_expr() );
817	} // if
818	// return the lowest cost alternative for the argument
819	Alternative &choice = winners.front();
820	alternatives.push_back( Alternative( new SizeofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
821	} // if
822	}
823
824	void AlternativeFinder::visit( AlignofExpr *alignofExpr ) {
825	if ( alignofExpr->get_isType() ) {
826	alternatives.push_back( Alternative( alignofExpr->clone(), env, Cost::zero ) );
827	} else {
828	// find all alternatives for the argument to sizeof
829	AlternativeFinder finder( indexer, env );
830	finder.find( alignofExpr->get_expr() );
831	// find the lowest cost alternative among the alternatives, otherwise ambiguous
832	AltList winners;
833	findMinCost( finder.alternatives.begin(), finder.alternatives.end(), back_inserter( winners ) );
834	if ( winners.size() != 1 ) {
835	throw SemanticError( "Ambiguous expression in alignof operand: ", alignofExpr->get_expr() );
836	} // if
837	// return the lowest cost alternative for the argument
838	Alternative &choice = winners.front();
839	alternatives.push_back( Alternative( new AlignofExpr( choice.expr->clone() ), choice.env, Cost::zero ) );
840	} // if
841	}
842
843	template< typename StructOrUnionType >
844	void AlternativeFinder::addOffsetof( StructOrUnionType *aggInst, const std::string &name ) {
845	std::list< Declaration* > members;
846	aggInst->lookup( name, members );
847	for ( std::list< Declaration* >::const_iterator i = members.begin(); i != members.end(); ++i ) {
848	if ( DeclarationWithType dwt = dynamic_cast< DeclarationWithType >( *i ) ) {
849	alternatives.push_back( Alternative( new OffsetofExpr( aggInst->clone(), dwt->clone() ), env, Cost::zero ) );
850	renameTypes( alternatives.back().expr );
851	} else {
852	assert( false );
853	}
854	}
855	}
856
857	void AlternativeFinder::visit( UntypedOffsetofExpr *offsetofExpr ) {
858	AlternativeFinder funcFinder( indexer, env );
859	if ( StructInstType structInst = dynamic_cast< StructInstType >( offsetofExpr->get_type() ) ) {
860	addOffsetof( structInst, offsetofExpr->get_member() );
861	} else if ( UnionInstType unionInst = dynamic_cast< UnionInstType >( offsetofExpr->get_type() ) ) {
862	addOffsetof( unionInst, offsetofExpr->get_member() );
863	}
864	}
865
866	void AlternativeFinder::visit( OffsetofExpr *offsetofExpr ) {
867	alternatives.push_back( Alternative( offsetofExpr->clone(), env, Cost::zero ) );
868	}
869
870	void AlternativeFinder::visit( OffsetPackExpr *offsetPackExpr ) {
871	alternatives.push_back( Alternative( offsetPackExpr->clone(), env, Cost::zero ) );
872	}
873
874	void AlternativeFinder::resolveAttr( DeclarationWithType funcDecl, FunctionType function, Type *argType, const TypeEnvironment &env ) {
875	// assume no polymorphism
876	// assume no implicit conversions
877	assert( function->get_parameters().size() == 1 );
878	PRINT(
879	std::cerr << "resolvAttr: funcDecl is ";
880	funcDecl->print( std::cerr );
881	std::cerr << " argType is ";
882	argType->print( std::cerr );
883	std::cerr << std::endl;
884	)
885	if ( typesCompatibleIgnoreQualifiers( argType, function->get_parameters().front()->get_type(), indexer, env ) ) {
886	alternatives.push_back( Alternative( new AttrExpr( new VariableExpr( funcDecl ), argType->clone() ), env, Cost::zero ) );
887	for ( std::list< DeclarationWithType* >::iterator i = function->get_returnVals().begin(); i != function->get_returnVals().end(); ++i ) {
888	alternatives.back().expr->get_results().push_back( (*i)->get_type()->clone() );
889	} // for
890	} // if
891	}
892
893	void AlternativeFinder::visit( AttrExpr *attrExpr ) {
894	// assume no 'pointer-to-attribute'
895	NameExpr nameExpr = dynamic_cast< NameExpr >( attrExpr->get_attr() );
896	assert( nameExpr );
897	std::list< DeclarationWithType* > attrList;
898	indexer.lookupId( nameExpr->get_name(), attrList );
899	if ( attrExpr->get_isType() \|\| attrExpr->get_expr() ) {
900	for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
901	// check if the type is function
902	if ( FunctionType function = dynamic_cast< FunctionType >( (*i)->get_type() ) ) {
903	// assume exactly one parameter
904	if ( function->get_parameters().size() == 1 ) {
905	if ( attrExpr->get_isType() ) {
906	resolveAttr( *i, function, attrExpr->get_type(), env );
907	} else {
908	AlternativeFinder finder( indexer, env );
909	finder.find( attrExpr->get_expr() );
910	for ( AltList::iterator choice = finder.alternatives.begin(); choice != finder.alternatives.end(); ++choice ) {
911	if ( choice->expr->get_results().size() == 1 ) {
912	resolveAttr(*i, function, choice->expr->get_results().front(), choice->env );
913	} // fi
914	} // for
915	} // if
916	} // if
917	} // if
918	} // for
919	} else {
920	for ( std::list< DeclarationWithType* >::iterator i = attrList.begin(); i != attrList.end(); ++i ) {
921	VariableExpr newExpr( *i );
922	alternatives.push_back( Alternative( newExpr.clone(), env, Cost() ) );
923	renameTypes( alternatives.back().expr );
924	} // for
925	} // if
926	}
927
928	void AlternativeFinder::visit( LogicalExpr *logicalExpr ) {
929	AlternativeFinder firstFinder( indexer, env );
930	firstFinder.findWithAdjustment( logicalExpr->get_arg1() );
931	for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
932	AlternativeFinder secondFinder( indexer, first->env );
933	secondFinder.findWithAdjustment( logicalExpr->get_arg2() );
934	for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
935	LogicalExpr *newExpr = new LogicalExpr( first->expr->clone(), second->expr->clone(), logicalExpr->get_isAnd() );
936	alternatives.push_back( Alternative( newExpr, second->env, first->cost + second->cost ) );
937	}
938	}
939	}
940
941	void AlternativeFinder::visit( ConditionalExpr *conditionalExpr ) {
942	AlternativeFinder firstFinder( indexer, env );
943	firstFinder.findWithAdjustment( conditionalExpr->get_arg1() );
944	for ( AltList::const_iterator first = firstFinder.alternatives.begin(); first != firstFinder.alternatives.end(); ++first ) {
945	AlternativeFinder secondFinder( indexer, first->env );
946	secondFinder.findWithAdjustment( conditionalExpr->get_arg2() );
947	for ( AltList::const_iterator second = secondFinder.alternatives.begin(); second != secondFinder.alternatives.end(); ++second ) {
948	AlternativeFinder thirdFinder( indexer, second->env );
949	thirdFinder.findWithAdjustment( conditionalExpr->get_arg3() );
950	for ( AltList::const_iterator third = thirdFinder.alternatives.begin(); third != thirdFinder.alternatives.end(); ++third ) {
951	OpenVarSet openVars;
952	AssertionSet needAssertions, haveAssertions;
953	Alternative newAlt( 0, third->env, first->cost + second->cost + third->cost );
954	std::list< Type* > commonTypes;
955	if ( unifyList( second->expr->get_results().begin(), second->expr->get_results().end(), third->expr->get_results().begin(), third->expr->get_results().end(), newAlt.env, needAssertions, haveAssertions, openVars, indexer, commonTypes ) ) {
956	ConditionalExpr *newExpr = new ConditionalExpr( first->expr->clone(), second->expr->clone(), third->expr->clone() );
957	std::list< Type* >::const_iterator original = second->expr->get_results().begin();
958	std::list< Type* >::const_iterator commonType = commonTypes.begin();
959	for ( ; original != second->expr->get_results().end() && commonType != commonTypes.end(); ++original, ++commonType ) {
960	if ( *commonType ) {
961	newExpr->get_results().push_back( *commonType );
962	} else {
963	newExpr->get_results().push_back( (*original)->clone() );
964	} // if
965	} // for
966	newAlt.expr = newExpr;
967	inferParameters( needAssertions, haveAssertions, newAlt, openVars, back_inserter( alternatives ) );
968	} // if
969	} // for
970	} // for
971	} // for
972	}
973
974	void AlternativeFinder::visit( CommaExpr *commaExpr ) {
975	TypeEnvironment newEnv( env );
976	Expression *newFirstArg = resolveInVoidContext( commaExpr->get_arg1(), indexer, newEnv );
977	AlternativeFinder secondFinder( indexer, newEnv );
978	secondFinder.findWithAdjustment( commaExpr->get_arg2() );
979	for ( AltList::const_iterator alt = secondFinder.alternatives.begin(); alt != secondFinder.alternatives.end(); ++alt ) {
980	alternatives.push_back( Alternative( new CommaExpr( newFirstArg->clone(), alt->expr->clone() ), alt->env, alt->cost ) );
981	} // for
982	delete newFirstArg;
983	}
984
985	void AlternativeFinder::visit( TupleExpr *tupleExpr ) {
986	std::list< AlternativeFinder > subExprAlternatives;
987	findSubExprs( tupleExpr->get_exprs().begin(), tupleExpr->get_exprs().end(), back_inserter( subExprAlternatives ) );
988	std::list< AltList > possibilities;
989	combos( subExprAlternatives.begin(), subExprAlternatives.end(), back_inserter( possibilities ) );
990	for ( std::list< AltList >::const_iterator i = possibilities.begin(); i != possibilities.end(); ++i ) {
991	TupleExpr *newExpr = new TupleExpr;
992	makeExprList( *i, newExpr->get_exprs() );
993	for ( std::list< Expression* >::const_iterator resultExpr = newExpr->get_exprs().begin(); resultExpr != newExpr->get_exprs().end(); ++resultExpr ) {
994	for ( std::list< Type* >::const_iterator resultType = (resultExpr)->get_results().begin(); resultType != (resultExpr)->get_results().end(); ++resultType ) {
995	newExpr->get_results().push_back( (*resultType)->clone() );
996	} // for
997	} // for
998
999	TypeEnvironment compositeEnv;
1000	simpleCombineEnvironments( i->begin(), i->end(), compositeEnv );
1001	alternatives.push_back( Alternative( newExpr, compositeEnv, sumCost( *i ) ) );
1002	} // for
1003	}
1004
1005	void AlternativeFinder::visit( ImplicitCopyCtorExpr * impCpCtorExpr ) {
1006	alternatives.push_back( Alternative( impCpCtorExpr->clone(), env, Cost::zero ) );
1007	}
1008	} // namespace ResolvExpr
1009
1010	// Local Variables: //
1011	// tab-width: 4 //
1012	// mode: c++ //
1013	// compile-command: "make install" //
1014	// End: //

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