source: src/ResolvExpr/Unify.cc@ c84e80a

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors deferred_resn demangler enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr new-env no_list persistent-indexer pthread-emulation qualifiedEnum resolv-new with_gc
Last change on this file since c84e80a was 6c3a988f, checked in by Rob Schluntz <rschlunt@…>, 9 years ago

fix inferred parameter data structures to correctly associate parameters with the entity that requested them, modify tuple specialization and unification to work with self-recursive assertions
  • Property mode set to 100644
File size: 29.8 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// Unify.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sun May 17 12:27:10 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Wed Mar 2 17:37:05 2016
13// Update Count : 37
14//
15
16#include <set>
17#include <memory>
18
19#include "Unify.h"
20#include "TypeEnvironment.h"
21#include "typeops.h"
22#include "FindOpenVars.h"
23#include "SynTree/Visitor.h"
24#include "SynTree/Type.h"
25#include "SynTree/Declaration.h"
26#include "SymTab/Indexer.h"
27#include "Common/utility.h"
28#include "Tuples/Tuples.h"
29
30// #define DEBUG
31
32namespace ResolvExpr {
33
34 class Unify : public Visitor {
35 public:
36 Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
37
38 bool get_result() const { return result; }
39 private:
40 virtual void visit(VoidType *voidType);
41 virtual void visit(BasicType *basicType);
42 virtual void visit(PointerType *pointerType);
43 virtual void visit(ArrayType *arrayType);
44 virtual void visit(FunctionType *functionType);
45 virtual void visit(StructInstType *aggregateUseType);
46 virtual void visit(UnionInstType *aggregateUseType);
47 virtual void visit(EnumInstType *aggregateUseType);
48 virtual void visit(TraitInstType *aggregateUseType);
49 virtual void visit(TypeInstType *aggregateUseType);
50 virtual void visit(TupleType *tupleType);
51 virtual void visit(VarArgsType *varArgsType);
52 virtual void visit(ZeroType *zeroType);
53 virtual void visit(OneType *oneType);
54
55 template< typename RefType > void handleRefType( RefType *inst, Type *other );
56 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
57
58 bool result;
59 Type *type2; // inherited
60 TypeEnvironment &env;
61 AssertionSet &needAssertions;
62 AssertionSet &haveAssertions;
63 const OpenVarSet &openVars;
64 WidenMode widenMode;
65 const SymTab::Indexer &indexer;
66 };
67
68 /// Attempts an inexact unification of type1 and type2.
69 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
70 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common );
71 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
72
73 bool typesCompatible( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
74 TypeEnvironment newEnv;
75 OpenVarSet openVars, closedVars; // added closedVars
76 AssertionSet needAssertions, haveAssertions;
77 Type *newFirst = first->clone(), *newSecond = second->clone();
78 env.apply( newFirst );
79 env.apply( newSecond );
80
81 // do we need to do this? Seems like we do, types should be able to be compatible if they
82 // have free variables that can unify
83 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
84 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
85
86 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
87 delete newFirst;
88 delete newSecond;
89 return result;
90 }
91
92 bool typesCompatibleIgnoreQualifiers( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
93 TypeEnvironment newEnv;
94 OpenVarSet openVars;
95 AssertionSet needAssertions, haveAssertions;
96 Type *newFirst = first->clone(), *newSecond = second->clone();
97 env.apply( newFirst );
98 env.apply( newSecond );
99 newFirst->get_qualifiers() = Type::Qualifiers();
100 newSecond->get_qualifiers() = Type::Qualifiers();
101/// std::cerr << "first is ";
102/// first->print( std::cerr );
103/// std::cerr << std::endl << "second is ";
104/// second->print( std::cerr );
105/// std::cerr << std::endl << "newFirst is ";
106/// newFirst->print( std::cerr );
107/// std::cerr << std::endl << "newSecond is ";
108/// newSecond->print( std::cerr );
109/// std::cerr << std::endl;
110 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
111 delete newFirst;
112 delete newSecond;
113 return result;
114 }
115
116 bool isFtype( Type *type, const SymTab::Indexer &indexer ) {
117 if ( dynamic_cast< FunctionType* >( type ) ) {
118 return true;
119 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( type ) ) {
120 return typeInst->get_isFtype();
121 } // if
122 return false;
123 }
124
125 struct CompleteTypeChecker : public Visitor {
126 virtual void visit( VoidType *basicType ) { status = false; }
127 virtual void visit( BasicType *basicType ) {}
128 virtual void visit( PointerType *pointerType ) {}
129 virtual void visit( ArrayType *arrayType ) { status = ! arrayType->get_isVarLen(); }
130 virtual void visit( FunctionType *functionType ) {}
131 virtual void visit( StructInstType *aggregateUseType ) { status = aggregateUseType->get_baseStruct()->has_body(); }
132 virtual void visit( UnionInstType *aggregateUseType ) { status = aggregateUseType->get_baseUnion()->has_body(); }
133 // xxx - enum inst does not currently contain a pointer to base, this should be fixed.
134 virtual void visit( EnumInstType *aggregateUseType ) { /* status = aggregateUseType->get_baseEnum()->hasBody(); */ }
135 virtual void visit( TraitInstType *aggregateUseType ) { assert( false ); }
136 virtual void visit( TypeInstType *aggregateUseType ) { status = aggregateUseType->get_baseType()->isComplete(); }
137 virtual void visit( TupleType *tupleType ) {} // xxx - not sure if this is right, might need to recursively check complete-ness
138 virtual void visit( TypeofType *typeofType ) { assert( false ); }
139 virtual void visit( AttrType *attrType ) { assert( false ); } // xxx - not sure what to do here
140 virtual void visit( VarArgsType *varArgsType ){} // xxx - is this right?
141 virtual void visit( ZeroType *zeroType ) {}
142 virtual void visit( OneType *oneType ) {}
143 bool status = true;
144 };
145 bool isComplete( Type * type ) {
146 CompleteTypeChecker checker;
147 assert( type );
148 type->accept( checker );
149 return checker.status;
150 }
151
152 bool tyVarCompatible( const TypeDecl::Data & data, Type *type, const SymTab::Indexer &indexer ) {
153 switch ( data.kind ) {
154 case TypeDecl::Any:
155 case TypeDecl::Dtype:
156 // to bind to an object type variable, the type must not be a function type.
157 // if the type variable is specified to be a complete type then the incoming
158 // type must also be complete
159 // xxx - should this also check that type is not a tuple type and that it's not a ttype?
160 return ! isFtype( type, indexer ) && (! data.isComplete || isComplete( type ));
161 case TypeDecl::Ftype:
162 return isFtype( type, indexer );
163 case TypeDecl::Ttype:
164 // ttype unifies with any tuple type
165 return dynamic_cast< TupleType * >( type );
166 } // switch
167 return false;
168 }
169
170 bool bindVar( TypeInstType *typeInst, Type *other, const TypeDecl::Data & data, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
171 OpenVarSet::const_iterator tyvar = openVars.find( typeInst->get_name() );
172 assert( tyvar != openVars.end() );
173 if ( ! tyVarCompatible( tyvar->second, other, indexer ) ) {
174 return false;
175 } // if
176 if ( occurs( other, typeInst->get_name(), env ) ) {
177 return false;
178 } // if
179 EqvClass curClass;
180 if ( env.lookup( typeInst->get_name(), curClass ) ) {
181 if ( curClass.type ) {
182 Type *common = 0;
183 // attempt to unify equivalence class type (which has qualifiers stripped, so they must be restored) with the type to bind to
184 std::auto_ptr< Type > newType( curClass.type->clone() );
185 newType->get_qualifiers() = typeInst->get_qualifiers();
186 if ( unifyInexact( newType.get(), other, env, needAssertions, haveAssertions, openVars, widenMode & WidenMode( curClass.allowWidening, true ), indexer, common ) ) {
187 if ( common ) {
188 common->get_qualifiers() = Type::Qualifiers();
189 delete curClass.type;
190 curClass.type = common;
191 env.add( curClass );
192 } // if
193 return true;
194 } else {
195 return false;
196 } // if
197 } else {
198 curClass.type = other->clone();
199 curClass.type->get_qualifiers() = Type::Qualifiers();
200 curClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
201 env.add( curClass );
202 } // if
203 } else {
204 EqvClass newClass;
205 newClass.vars.insert( typeInst->get_name() );
206 newClass.type = other->clone();
207 newClass.type->get_qualifiers() = Type::Qualifiers();
208 newClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
209 newClass.data = data;
210 env.add( newClass );
211 } // if
212 return true;
213 }
214
215 bool bindVarToVar( TypeInstType *var1, TypeInstType *var2, const TypeDecl::Data & data, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
216 bool result = true;
217 EqvClass class1, class2;
218 bool hasClass1 = false, hasClass2 = false;
219 bool widen1 = false, widen2 = false;
220 Type *type1 = 0, *type2 = 0;
221
222 if ( env.lookup( var1->get_name(), class1 ) ) {
223 hasClass1 = true;
224 if ( class1.type ) {
225 if ( occurs( class1.type, var2->get_name(), env ) ) {
226 return false;
227 } // if
228 type1 = class1.type->clone();
229 } // if
230 widen1 = widenMode.widenFirst && class1.allowWidening;
231 } // if
232 if ( env.lookup( var2->get_name(), class2 ) ) {
233 hasClass2 = true;
234 if ( class2.type ) {
235 if ( occurs( class2.type, var1->get_name(), env ) ) {
236 return false;
237 } // if
238 type2 = class2.type->clone();
239 } // if
240 widen2 = widenMode.widenSecond && class2.allowWidening;
241 } // if
242
243 if ( type1 && type2 ) {
244// std::cerr << "has type1 && type2" << std::endl;
245 WidenMode newWidenMode ( widen1, widen2 );
246 Type *common = 0;
247 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, newWidenMode, indexer, common ) ) {
248 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
249 class1.allowWidening = widen1 && widen2;
250 if ( common ) {
251 common->get_qualifiers() = Type::Qualifiers();
252 delete class1.type;
253 class1.type = common;
254 } // if
255 env.add( class1 );
256 } else {
257 result = false;
258 } // if
259 } else if ( hasClass1 && hasClass2 ) {
260 if ( type1 ) {
261 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
262 class1.allowWidening = widen1;
263 env.add( class1 );
264 } else {
265 class2.vars.insert( class1.vars.begin(), class1.vars.end() );
266 class2.allowWidening = widen2;
267 env.add( class2 );
268 } // if
269 } else if ( hasClass1 ) {
270 class1.vars.insert( var2->get_name() );
271 class1.allowWidening = widen1;
272 env.add( class1 );
273 } else if ( hasClass2 ) {
274 class2.vars.insert( var1->get_name() );
275 class2.allowWidening = widen2;
276 env.add( class2 );
277 } else {
278 EqvClass newClass;
279 newClass.vars.insert( var1->get_name() );
280 newClass.vars.insert( var2->get_name() );
281 newClass.allowWidening = widen1 && widen2;
282 newClass.data = data;
283 env.add( newClass );
284 } // if
285 delete type1;
286 delete type2;
287 return result;
288 }
289
290 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
291 OpenVarSet closedVars;
292 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
293 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
294 Type *commonType = 0;
295 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
296 if ( commonType ) {
297 delete commonType;
298 } // if
299 return true;
300 } else {
301 return false;
302 } // if
303 }
304
305 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
306 OpenVarSet closedVars;
307 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
308 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
309 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
310 }
311
312 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
313#ifdef DEBUG
314 TypeEnvironment debugEnv( env );
315#endif
316 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
317 return false;
318 }
319
320 bool result;
321 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
322 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
323 OpenVarSet::const_iterator entry1, entry2;
324 if ( var1 ) {
325 entry1 = openVars.find( var1->get_name() );
326 } // if
327 if ( var2 ) {
328 entry2 = openVars.find( var2->get_name() );
329 } // if
330 bool isopen1 = var1 && ( entry1 != openVars.end() );
331 bool isopen2 = var2 && ( entry2 != openVars.end() );
332
333 if ( isopen1 && isopen2 && entry1->second == entry2->second ) {
334 result = bindVarToVar( var1, var2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
335 } else if ( isopen1 ) {
336 result = bindVar( var1, type2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
337 } else if ( isopen2 ) {
338 result = bindVar( var2, type1, entry2->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
339 } else {
340 Unify comparator( type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
341 type1->accept( comparator );
342 result = comparator.get_result();
343 } // if
344#ifdef DEBUG
345 std::cerr << "============ unifyExact" << std::endl;
346 std::cerr << "type1 is ";
347 type1->print( std::cerr );
348 std::cerr << std::endl << "type2 is ";
349 type2->print( std::cerr );
350 std::cerr << std::endl << "openVars are ";
351 printOpenVarSet( openVars, std::cerr, 8 );
352 std::cerr << std::endl << "input env is " << std::endl;
353 debugEnv.print( std::cerr, 8 );
354 std::cerr << std::endl << "result env is " << std::endl;
355 env.print( std::cerr, 8 );
356 std::cerr << "result is " << result << std::endl;
357#endif
358 return result;
359 }
360
361 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
362 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
363 }
364
365 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common ) {
366 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
367 type1->get_qualifiers() = Type::Qualifiers();
368 type2->get_qualifiers() = Type::Qualifiers();
369 bool result;
370#ifdef DEBUG
371 std::cerr << "unifyInexact type 1 is ";
372 type1->print( std::cerr );
373 std::cerr << "type 2 is ";
374 type2->print( std::cerr );
375 std::cerr << std::endl;
376#endif
377 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer ) ) {
378#ifdef DEBUG
379 std::cerr << "unifyInexact: no exact unification found" << std::endl;
380#endif
381 if ( ( common = commonType( type1, type2, widenMode.widenFirst, widenMode.widenSecond, indexer, env, openVars ) ) ) {
382 common->get_qualifiers() = tq1 + tq2;
383#ifdef DEBUG
384 std::cerr << "unifyInexact: common type is ";
385 common->print( std::cerr );
386 std::cerr << std::endl;
387#endif
388 result = true;
389 } else {
390#ifdef DEBUG
391 std::cerr << "unifyInexact: no common type found" << std::endl;
392#endif
393 result = false;
394 } // if
395 } else {
396 if ( tq1 != tq2 ) {
397 if ( ( tq1 > tq2 || widenMode.widenFirst ) && ( tq2 > tq1 || widenMode.widenSecond ) ) {
398 common = type1->clone();
399 common->get_qualifiers() = tq1 + tq2;
400 result = true;
401 } else {
402 result = false;
403 } // if
404 } else {
405 result = true;
406 } // if
407 } // if
408 type1->get_qualifiers() = tq1;
409 type2->get_qualifiers() = tq2;
410 return result;
411 }
412
413 Unify::Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer )
414 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widenMode( widenMode ), indexer( indexer ) {
415 }
416
417 void Unify::visit(VoidType *voidType) {
418 result = dynamic_cast< VoidType* >( type2 );
419 }
420
421 void Unify::visit(BasicType *basicType) {
422 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
423 result = basicType->get_kind() == otherBasic->get_kind();
424 } // if
425 }
426
427 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
428/// std::cerr << "assertion set is" << std::endl;
429/// printAssertionSet( assertions, std::cerr, 8 );
430/// std::cerr << "looking for ";
431/// assert->print( std::cerr );
432/// std::cerr << std::endl;
433 AssertionSet::iterator i = assertions.find( assert );
434 if ( i != assertions.end() ) {
435/// std::cerr << "found it!" << std::endl;
436 i->second.isUsed = true;
437 } // if
438 }
439
440 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
441 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
442 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
443 markAssertionSet( assertion1, *assert );
444 markAssertionSet( assertion2, *assert );
445 } // for
446 } // for
447 }
448
449 void Unify::visit(PointerType *pointerType) {
450 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
451 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
452 markAssertions( haveAssertions, needAssertions, pointerType );
453 markAssertions( haveAssertions, needAssertions, otherPointer );
454 } // if
455 }
456
457 void Unify::visit(ArrayType *arrayType) {
458 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
459 // to unify, array types must both be VLA or both not VLA
460 // and must both have a dimension expression or not have a dimension
461 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
462
463 // not positive this is correct in all cases, but it's needed for typedefs
464 if ( arrayType->get_isVarLen() || otherArray->get_isVarLen() ) {
465 return;
466 }
467
468 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
469 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
470 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
471 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
472 // see C11 Reference Manual 6.7.6.2.6
473 // two array types with size specifiers that are integer constant expressions are
474 // compatible if both size specifiers have the same constant value
475 if ( ce1 && ce2 ) {
476 Constant * c1 = ce1->get_constant();
477 Constant * c2 = ce2->get_constant();
478
479 if ( c1->get_value() != c2->get_value() ) {
480 // does not unify if the dimension is different
481 return;
482 }
483 }
484 }
485
486 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
487 } // if
488 }
489
490 template< typename Iterator >
491 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end ) {
492 std::list< Type * > types;
493 for ( ; begin != end; ++begin ) {
494 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
495 flatten( (*begin)->get_type(), back_inserter( types ) );
496 }
497 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
498 }
499
500 template< typename Iterator1, typename Iterator2 >
501 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
502 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
503 Type * t1 = (*list1Begin)->get_type();
504 Type * t2 = (*list2Begin)->get_type();
505 bool isTtype1 = Tuples::isTtype( t1 );
506 bool isTtype2 = Tuples::isTtype( t2 );
507 // xxx - assumes ttype must be last parameter
508 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
509 if ( isTtype1 && ! isTtype2 ) {
510 // combine all of the things in list2, then unify
511 return unifyExact( t1, combineTypes( list2Begin, list2End ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
512 } else if ( isTtype2 && ! isTtype1 ) {
513 // combine all of the things in list1, then unify
514 return unifyExact( combineTypes( list1Begin, list1End ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
515 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
516 return false;
517 } // if
518 } // for
519 // may get to the end of one argument list before the end of the other. This is only okay when the other is a ttype
520 if ( list1Begin != list1End ) {
521 // try unifying empty tuple type with ttype
522 Type * t1 = (*list1Begin)->get_type();
523 if ( Tuples::isTtype( t1 ) ) {
524 return unifyExact( t1, combineTypes( list2Begin, list2End ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
525 } else return false;
526 } else if ( list2Begin != list2End ) {
527 // try unifying empty tuple type with ttype
528 Type * t2 = (*list2Begin)->get_type();
529 if ( Tuples::isTtype( t2 ) ) {
530 return unifyExact( combineTypes( list1Begin, list1End ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
531 } else return false;
532 } else {
533 return true;
534 } // if
535 }
536
537 /// Finds ttypes and replaces them with their expansion, if known.
538 /// This needs to be done so that satisfying ttype assertions is easier.
539 /// If this isn't done then argument lists can have wildly different
540 /// size and structure, when they should be compatible.
541 struct TtypeExpander : public Mutator {
542 TypeEnvironment & env;
543 TtypeExpander( TypeEnvironment & env ) : env( env ) {}
544 Type * mutate( TypeInstType * typeInst ) {
545 EqvClass eqvClass;
546 if ( env.lookup( typeInst->get_name(), eqvClass ) ) {
547 if ( eqvClass.data.kind == TypeDecl::Ttype ) {
548 // expand ttype parameter into its actual type
549 if ( eqvClass.type ) {
550 delete typeInst;
551 return eqvClass.type->clone();
552 }
553 }
554 }
555 return typeInst;
556 }
557 };
558
559 /// flattens a list of declarations, so that each tuple type has a single declaration.
560 /// makes use of TtypeExpander to ensure ttypes are flat as well.
561 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
562 dst.clear();
563 for ( DeclarationWithType * dcl : src ) {
564 TtypeExpander expander( env );
565 dcl->acceptMutator( expander );
566 std::list< Type * > types;
567 flatten( dcl->get_type(), back_inserter( types ) );
568 for ( Type * t : types ) {
569 dst.push_back( new ObjectDecl( "", DeclarationNode::NoStorageClass, LinkageSpec::C, nullptr, t, nullptr ) );
570 }
571 delete dcl;
572 }
573 }
574
575 void Unify::visit(FunctionType *functionType) {
576 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
577 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
578 // flatten the parameter lists for both functions so that tuple structure
579 // doesn't affect unification. Must be a clone so that the types don't change.
580 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
581 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
582 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
583 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
584
585 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
586 if ( (flatFunc->get_parameters().size() == flatOther->get_parameters().size() && flatFunc->get_returnVals().size() == flatOther->get_returnVals().size()) || flatFunc->isTtype() || flatOther->isTtype() ) {
587 if ( unifyDeclList( flatFunc->get_parameters().begin(), flatFunc->get_parameters().end(), flatOther->get_parameters().begin(), flatOther->get_parameters().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
588 if ( unifyDeclList( flatFunc->get_returnVals().begin(), flatFunc->get_returnVals().end(), flatOther->get_returnVals().begin(), flatOther->get_returnVals().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
589
590 // the original types must be used in mark assertions, since pointer comparisons are used
591 markAssertions( haveAssertions, needAssertions, functionType );
592 markAssertions( haveAssertions, needAssertions, otherFunction );
593
594 result = true;
595 } // if
596 } // if
597 } // if
598 } // if
599 }
600
601 template< typename RefType >
602 void Unify::handleRefType( RefType *inst, Type *other ) {
603 // check that other type is compatible and named the same
604 RefType *otherStruct = dynamic_cast< RefType* >( other );
605 result = otherStruct && inst->get_name() == otherStruct->get_name();
606 }
607
608 template< typename RefType >
609 void Unify::handleGenericRefType( RefType *inst, Type *other ) {
610 // Check that other type is compatible and named the same
611 handleRefType( inst, other );
612 if ( ! result ) return;
613 // Check that parameters of types unify, if any
614 std::list< Expression* > params = inst->get_parameters();
615 std::list< Expression* > otherParams = ((RefType*)other)->get_parameters();
616
617 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
618 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
619 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
620 assert(param && "Aggregate parameters should be type expressions");
621 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
622 assert(otherParam && "Aggregate parameters should be type expressions");
623
624 if ( ! unifyExact( param->get_type(), otherParam->get_type(), env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
625 result = false;
626 return;
627 }
628 }
629 result = ( it == params.end() && jt == otherParams.end() );
630 }
631
632 void Unify::visit(StructInstType *structInst) {
633 handleGenericRefType( structInst, type2 );
634 }
635
636 void Unify::visit(UnionInstType *unionInst) {
637 handleGenericRefType( unionInst, type2 );
638 }
639
640 void Unify::visit(EnumInstType *enumInst) {
641 handleRefType( enumInst, type2 );
642 }
643
644 void Unify::visit(TraitInstType *contextInst) {
645 handleRefType( contextInst, type2 );
646 }
647
648 void Unify::visit(TypeInstType *typeInst) {
649 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
650 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
651 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
652 result = true;
653/// } else {
654/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
655/// if ( nt ) {
656/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
657/// assert( type );
658/// if ( type->get_base() ) {
659/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
660/// }
661/// }
662 } // if
663 }
664
665 template< typename Iterator1, typename Iterator2 >
666 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
667 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
668 Type *commonType = 0;
669 if ( ! unifyInexact( *list1Begin, *list2Begin, env, needAssertions, haveAssertions, openVars, widenMode, indexer, commonType ) ) {
670 return false;
671 }
672 delete commonType;
673 } // for
674 if ( list1Begin != list1End || list2Begin != list2End ) {
675 return false;
676 } else {
677 return true;
678 } //if
679 }
680
681 void Unify::visit(TupleType *tupleType) {
682 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
683 result = unifyList( tupleType->get_types().begin(), tupleType->get_types().end(), otherTuple->get_types().begin(), otherTuple->get_types().end(), env, needAssertions, haveAssertions, openVars, widenMode, indexer );
684 } // if
685 }
686
687 void Unify::visit(VarArgsType *varArgsType) {
688 result = dynamic_cast< VarArgsType* >( type2 );
689 }
690
691 void Unify::visit(ZeroType *zeroType) {
692 result = dynamic_cast< ZeroType* >( type2 );
693 }
694
695 void Unify::visit(OneType *oneType) {
696 result = dynamic_cast< OneType* >( type2 );
697 }
698
699 // xxx - compute once and store in the FunctionType?
700 Type * extractResultType( FunctionType * function ) {
701 if ( function->get_returnVals().size() == 0 ) {
702 return new VoidType( Type::Qualifiers() );
703 } else if ( function->get_returnVals().size() == 1 ) {
704 return function->get_returnVals().front()->get_type()->clone();
705 } else {
706 TupleType * tupleType = new TupleType( Type::Qualifiers() );
707 for ( DeclarationWithType * decl : function->get_returnVals() ) {
708 tupleType->get_types().push_back( decl->get_type()->clone() );
709 } // for
710 return tupleType;
711 }
712 }
713} // namespace ResolvExpr
714
715// Local Variables: //
716// tab-width: 4 //
717// mode: c++ //
718// compile-command: "make install" //
719// End: //
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