source: src/ResolvExpr/Unify.cc@ 33f5b57

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 with_gc
Last change on this file since 33f5b57 was 1dcd52a3, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

Disregard outermost const, volatile, _Atomic qualifiers on parameters when unifying function types [fixes #48]
  • Property mode set to 100644
File size: 33.3 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 : Thu Mar 16 16:22:54 2017
13// Update Count : 42
14//
15
16#include <cassert> // for assertf, assert
17#include <iterator> // for back_insert_iterator, back_inserter
18#include <map> // for _Rb_tree_const_iterator, _Rb_tree_i...
19#include <memory> // for unique_ptr
20#include <set> // for set
21#include <string> // for string, operator==, operator!=, bas...
22#include <utility> // for pair
23
24#include "Common/PassVisitor.h" // for PassVisitor
25#include "FindOpenVars.h" // for findOpenVars
26#include "Parser/LinkageSpec.h" // for C
27#include "SynTree/Constant.h" // for Constant
28#include "SynTree/Declaration.h" // for TypeDecl, TypeDecl::Data, Declarati...
29#include "SynTree/Expression.h" // for TypeExpr, Expression, ConstantExpr
30#include "SynTree/Mutator.h" // for Mutator
31#include "SynTree/Type.h" // for Type, TypeInstType, FunctionType
32#include "SynTree/Visitor.h" // for Visitor
33#include "Tuples/Tuples.h" // for isTtype
34#include "TypeEnvironment.h" // for EqvClass, AssertionSet, OpenVarSet
35#include "Unify.h"
36#include "typeops.h" // for flatten, occurs, commonType
37
38namespace SymTab {
39class Indexer;
40} // namespace SymTab
41
42// #define DEBUG
43
44namespace ResolvExpr {
45
46 struct Unify : public WithShortCircuiting {
47 Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
48
49 bool get_result() const { return result; }
50
51 void previsit( BaseSyntaxNode * ) { visit_children = false; }
52
53 void postvisit( VoidType * voidType );
54 void postvisit( BasicType * basicType );
55 void postvisit( PointerType * pointerType );
56 void postvisit( ArrayType * arrayType );
57 void postvisit( ReferenceType * refType );
58 void postvisit( FunctionType * functionType );
59 void postvisit( StructInstType * aggregateUseType );
60 void postvisit( UnionInstType * aggregateUseType );
61 void postvisit( EnumInstType * aggregateUseType );
62 void postvisit( TraitInstType * aggregateUseType );
63 void postvisit( TypeInstType * aggregateUseType );
64 void postvisit( TupleType * tupleType );
65 void postvisit( VarArgsType * varArgsType );
66 void postvisit( ZeroType * zeroType );
67 void postvisit( OneType * oneType );
68
69 private:
70 template< typename RefType > void handleRefType( RefType *inst, Type *other );
71 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
72
73 bool result;
74 Type *type2; // inherited
75 TypeEnvironment &env;
76 AssertionSet &needAssertions;
77 AssertionSet &haveAssertions;
78 const OpenVarSet &openVars;
79 WidenMode widenMode;
80 const SymTab::Indexer &indexer;
81 };
82
83 /// Attempts an inexact unification of type1 and type2.
84 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
85 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common );
86 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
87
88 bool typesCompatible( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
89 TypeEnvironment newEnv;
90 OpenVarSet openVars, closedVars; // added closedVars
91 AssertionSet needAssertions, haveAssertions;
92 Type *newFirst = first->clone(), *newSecond = second->clone();
93 env.apply( newFirst );
94 env.apply( newSecond );
95
96 // do we need to do this? Seems like we do, types should be able to be compatible if they
97 // have free variables that can unify
98 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
99 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
100
101 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
102 delete newFirst;
103 delete newSecond;
104 return result;
105 }
106
107 bool typesCompatibleIgnoreQualifiers( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
108 TypeEnvironment newEnv;
109 OpenVarSet openVars;
110 AssertionSet needAssertions, haveAssertions;
111 Type *newFirst = first->clone(), *newSecond = second->clone();
112 env.apply( newFirst );
113 env.apply( newSecond );
114 newFirst->get_qualifiers() = Type::Qualifiers();
115 newSecond->get_qualifiers() = Type::Qualifiers();
116/// std::cerr << "first is ";
117/// first->print( std::cerr );
118/// std::cerr << std::endl << "second is ";
119/// second->print( std::cerr );
120/// std::cerr << std::endl << "newFirst is ";
121/// newFirst->print( std::cerr );
122/// std::cerr << std::endl << "newSecond is ";
123/// newSecond->print( std::cerr );
124/// std::cerr << std::endl;
125 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
126 delete newFirst;
127 delete newSecond;
128 return result;
129 }
130
131 bool isFtype( Type *type ) {
132 if ( dynamic_cast< FunctionType* >( type ) ) {
133 return true;
134 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( type ) ) {
135 return typeInst->get_isFtype();
136 } // if
137 return false;
138 }
139
140 bool tyVarCompatible( const TypeDecl::Data & data, Type *type ) {
141 switch ( data.kind ) {
142 case TypeDecl::Dtype:
143 // to bind to an object type variable, the type must not be a function type.
144 // if the type variable is specified to be a complete type then the incoming
145 // type must also be complete
146 // xxx - should this also check that type is not a tuple type and that it's not a ttype?
147 return ! isFtype( type ) && (! data.isComplete || type->isComplete() );
148 case TypeDecl::Ftype:
149 return isFtype( type );
150 case TypeDecl::Ttype:
151 // ttype unifies with any tuple type
152 return dynamic_cast< TupleType * >( type ) || Tuples::isTtype( type );
153 } // switch
154 return false;
155 }
156
157 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 ) {
158 // remove references from other, so that type variables can only bind to value types
159 other = other->stripReferences();
160 OpenVarSet::const_iterator tyvar = openVars.find( typeInst->get_name() );
161 assert( tyvar != openVars.end() );
162 if ( ! tyVarCompatible( tyvar->second, other ) ) {
163 return false;
164 } // if
165 if ( occurs( other, typeInst->get_name(), env ) ) {
166 return false;
167 } // if
168 EqvClass curClass;
169 if ( env.lookup( typeInst->get_name(), curClass ) ) {
170 if ( curClass.type ) {
171 Type *common = 0;
172 // attempt to unify equivalence class type (which has qualifiers stripped, so they must be restored) with the type to bind to
173 std::unique_ptr< Type > newType( curClass.type->clone() );
174 newType->get_qualifiers() = typeInst->get_qualifiers();
175 if ( unifyInexact( newType.get(), other, env, needAssertions, haveAssertions, openVars, widenMode & WidenMode( curClass.allowWidening, true ), indexer, common ) ) {
176 if ( common ) {
177 common->get_qualifiers() = Type::Qualifiers();
178 delete curClass.type;
179 curClass.type = common;
180 env.add( curClass );
181 } // if
182 return true;
183 } else {
184 return false;
185 } // if
186 } else {
187 curClass.type = other->clone();
188 curClass.type->get_qualifiers() = Type::Qualifiers();
189 curClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
190 env.add( curClass );
191 } // if
192 } else {
193 EqvClass newClass;
194 newClass.vars.insert( typeInst->get_name() );
195 newClass.type = other->clone();
196 newClass.type->get_qualifiers() = Type::Qualifiers();
197 newClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
198 newClass.data = data;
199 env.add( newClass );
200 } // if
201 return true;
202 }
203
204 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 ) {
205 bool result = true;
206 EqvClass class1, class2;
207 bool hasClass1 = false, hasClass2 = false;
208 bool widen1 = false, widen2 = false;
209 Type *type1 = 0, *type2 = 0;
210
211 if ( env.lookup( var1->get_name(), class1 ) ) {
212 hasClass1 = true;
213 if ( class1.type ) {
214 if ( occurs( class1.type, var2->get_name(), env ) ) {
215 return false;
216 } // if
217 type1 = class1.type->clone();
218 } // if
219 widen1 = widenMode.widenFirst && class1.allowWidening;
220 } // if
221 if ( env.lookup( var2->get_name(), class2 ) ) {
222 hasClass2 = true;
223 if ( class2.type ) {
224 if ( occurs( class2.type, var1->get_name(), env ) ) {
225 return false;
226 } // if
227 type2 = class2.type->clone();
228 } // if
229 widen2 = widenMode.widenSecond && class2.allowWidening;
230 } // if
231
232 if ( type1 && type2 ) {
233// std::cerr << "has type1 && type2" << std::endl;
234 WidenMode newWidenMode ( widen1, widen2 );
235 Type *common = 0;
236 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, newWidenMode, indexer, common ) ) {
237 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
238 class1.allowWidening = widen1 && widen2;
239 if ( common ) {
240 common->get_qualifiers() = Type::Qualifiers();
241 delete class1.type;
242 class1.type = common;
243 } // if
244 env.add( class1 );
245 } else {
246 result = false;
247 } // if
248 } else if ( hasClass1 && hasClass2 ) {
249 if ( type1 ) {
250 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
251 class1.allowWidening = widen1;
252 env.add( class1 );
253 } else {
254 class2.vars.insert( class1.vars.begin(), class1.vars.end() );
255 class2.allowWidening = widen2;
256 env.add( class2 );
257 } // if
258 } else if ( hasClass1 ) {
259 class1.vars.insert( var2->get_name() );
260 class1.allowWidening = widen1;
261 env.add( class1 );
262 } else if ( hasClass2 ) {
263 class2.vars.insert( var1->get_name() );
264 class2.allowWidening = widen2;
265 env.add( class2 );
266 } else {
267 EqvClass newClass;
268 newClass.vars.insert( var1->get_name() );
269 newClass.vars.insert( var2->get_name() );
270 newClass.allowWidening = widen1 && widen2;
271 newClass.data = data;
272 env.add( newClass );
273 } // if
274 delete type1;
275 delete type2;
276 return result;
277 }
278
279 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
280 OpenVarSet closedVars;
281 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
282 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
283 Type *commonType = 0;
284 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
285 if ( commonType ) {
286 delete commonType;
287 } // if
288 return true;
289 } else {
290 return false;
291 } // if
292 }
293
294 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
295 OpenVarSet closedVars;
296 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
297 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
298 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
299 }
300
301 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
302#ifdef DEBUG
303 TypeEnvironment debugEnv( env );
304#endif
305 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
306 return false;
307 }
308
309 bool result;
310 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
311 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
312 OpenVarSet::const_iterator entry1, entry2;
313 if ( var1 ) {
314 entry1 = openVars.find( var1->get_name() );
315 } // if
316 if ( var2 ) {
317 entry2 = openVars.find( var2->get_name() );
318 } // if
319 bool isopen1 = var1 && ( entry1 != openVars.end() );
320 bool isopen2 = var2 && ( entry2 != openVars.end() );
321
322 if ( isopen1 && isopen2 && entry1->second == entry2->second ) {
323 result = bindVarToVar( var1, var2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
324 } else if ( isopen1 ) {
325 result = bindVar( var1, type2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
326 } else if ( isopen2 ) {
327 result = bindVar( var2, type1, entry2->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
328 } else {
329 PassVisitor<Unify> comparator( type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
330 type1->accept( comparator );
331 result = comparator.pass.get_result();
332 } // if
333#ifdef DEBUG
334 std::cerr << "============ unifyExact" << std::endl;
335 std::cerr << "type1 is ";
336 type1->print( std::cerr );
337 std::cerr << std::endl << "type2 is ";
338 type2->print( std::cerr );
339 std::cerr << std::endl << "openVars are ";
340 printOpenVarSet( openVars, std::cerr, 8 );
341 std::cerr << std::endl << "input env is " << std::endl;
342 debugEnv.print( std::cerr, 8 );
343 std::cerr << std::endl << "result env is " << std::endl;
344 env.print( std::cerr, 8 );
345 std::cerr << "result is " << result << std::endl;
346#endif
347 return result;
348 }
349
350 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
351 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
352 }
353
354 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common ) {
355 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
356 type1->get_qualifiers() = Type::Qualifiers();
357 type2->get_qualifiers() = Type::Qualifiers();
358 bool result;
359#ifdef DEBUG
360 std::cerr << "unifyInexact type 1 is ";
361 type1->print( std::cerr );
362 std::cerr << " type 2 is ";
363 type2->print( std::cerr );
364 std::cerr << std::endl;
365#endif
366 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer ) ) {
367#ifdef DEBUG
368 std::cerr << "unifyInexact: no exact unification found" << std::endl;
369#endif
370 if ( ( common = commonType( type1, type2, widenMode.widenFirst, widenMode.widenSecond, indexer, env, openVars ) ) ) {
371 common->get_qualifiers() = tq1 | tq2;
372#ifdef DEBUG
373 std::cerr << "unifyInexact: common type is ";
374 common->print( std::cerr );
375 std::cerr << std::endl;
376#endif
377 result = true;
378 } else {
379#ifdef DEBUG
380 std::cerr << "unifyInexact: no common type found" << std::endl;
381#endif
382 result = false;
383 } // if
384 } else {
385 if ( tq1 != tq2 ) {
386 if ( ( tq1 > tq2 || widenMode.widenFirst ) && ( tq2 > tq1 || widenMode.widenSecond ) ) {
387 common = type1->clone();
388 common->get_qualifiers() = tq1 | tq2;
389 result = true;
390 } else {
391 result = false;
392 } // if
393 } else {
394 common = type1->clone();
395 common->get_qualifiers() = tq1 | tq2;
396 result = true;
397 } // if
398 } // if
399 type1->get_qualifiers() = tq1;
400 type2->get_qualifiers() = tq2;
401 return result;
402 }
403
404 Unify::Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer )
405 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widenMode( widenMode ), indexer( indexer ) {
406 }
407
408 void Unify::postvisit( __attribute__((unused)) VoidType *voidType) {
409 result = dynamic_cast< VoidType* >( type2 );
410 }
411
412 void Unify::postvisit(BasicType *basicType) {
413 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
414 result = basicType->get_kind() == otherBasic->get_kind();
415 } // if
416 }
417
418 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
419/// std::cerr << "assertion set is" << std::endl;
420/// printAssertionSet( assertions, std::cerr, 8 );
421/// std::cerr << "looking for ";
422/// assert->print( std::cerr );
423/// std::cerr << std::endl;
424 AssertionSet::iterator i = assertions.find( assert );
425 if ( i != assertions.end() ) {
426/// std::cerr << "found it!" << std::endl;
427 i->second.isUsed = true;
428 } // if
429 }
430
431 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
432 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
433 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
434 markAssertionSet( assertion1, *assert );
435 markAssertionSet( assertion2, *assert );
436 } // for
437 } // for
438 }
439
440 void Unify::postvisit(PointerType *pointerType) {
441 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
442 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
443 markAssertions( haveAssertions, needAssertions, pointerType );
444 markAssertions( haveAssertions, needAssertions, otherPointer );
445 } // if
446 }
447
448 void Unify::postvisit(ReferenceType *refType) {
449 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
450 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
451 markAssertions( haveAssertions, needAssertions, refType );
452 markAssertions( haveAssertions, needAssertions, otherRef );
453 } // if
454 }
455
456 void Unify::postvisit(ArrayType *arrayType) {
457 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
458 // to unify, array types must both be VLA or both not VLA
459 // and must both have a dimension expression or not have a dimension
460 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
461
462 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
463 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
464 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
465 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
466 // see C11 Reference Manual 6.7.6.2.6
467 // two array types with size specifiers that are integer constant expressions are
468 // compatible if both size specifiers have the same constant value
469 if ( ce1 && ce2 ) {
470 Constant * c1 = ce1->get_constant();
471 Constant * c2 = ce2->get_constant();
472
473 if ( c1->get_value() != c2->get_value() ) {
474 // does not unify if the dimension is different
475 return;
476 }
477 }
478 }
479
480 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
481 } // if
482 }
483
484 template< typename Iterator, typename Func >
485 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
486 std::list< Type * > types;
487 for ( ; begin != end; ++begin ) {
488 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
489 flatten( toType( *begin ), back_inserter( types ) );
490 }
491 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
492 }
493
494 template< typename Iterator1, typename Iterator2 >
495 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
496 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
497 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
498 Type * t1 = (*list1Begin)->get_type();
499 Type * t2 = (*list2Begin)->get_type();
500 bool isTtype1 = Tuples::isTtype( t1 );
501 bool isTtype2 = Tuples::isTtype( t2 );
502 // xxx - assumes ttype must be last parameter
503 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
504 if ( isTtype1 && ! isTtype2 ) {
505 // combine all of the things in list2, then unify
506 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
507 } else if ( isTtype2 && ! isTtype1 ) {
508 // combine all of the things in list1, then unify
509 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
510 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
511 return false;
512 } // if
513 } // for
514 // 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
515 if ( list1Begin != list1End ) {
516 // try unifying empty tuple type with ttype
517 Type * t1 = (*list1Begin)->get_type();
518 if ( Tuples::isTtype( t1 ) ) {
519 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
520 } else return false;
521 } else if ( list2Begin != list2End ) {
522 // try unifying empty tuple type with ttype
523 Type * t2 = (*list2Begin)->get_type();
524 if ( Tuples::isTtype( t2 ) ) {
525 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
526 } else return false;
527 } else {
528 return true;
529 } // if
530 }
531
532 /// Finds ttypes and replaces them with their expansion, if known.
533 /// This needs to be done so that satisfying ttype assertions is easier.
534 /// If this isn't done then argument lists can have wildly different
535 /// size and structure, when they should be compatible.
536 struct TtypeExpander : public WithShortCircuiting {
537 TypeEnvironment & tenv;
538 TtypeExpander( TypeEnvironment & tenv ) : tenv( tenv ) {}
539 void premutate( TypeInstType * ) { visit_children = false; }
540 Type * postmutate( TypeInstType * typeInst ) {
541 EqvClass eqvClass;
542 if ( tenv.lookup( typeInst->get_name(), eqvClass ) ) {
543 if ( eqvClass.data.kind == TypeDecl::Ttype ) {
544 // expand ttype parameter into its actual type
545 if ( eqvClass.type ) {
546 delete typeInst;
547 return eqvClass.type->clone();
548 }
549 }
550 }
551 return typeInst;
552 }
553 };
554
555 /// flattens a list of declarations, so that each tuple type has a single declaration.
556 /// makes use of TtypeExpander to ensure ttypes are flat as well.
557 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
558 dst.clear();
559 for ( DeclarationWithType * dcl : src ) {
560 PassVisitor<TtypeExpander> expander( env );
561 dcl->acceptMutator( expander );
562 std::list< Type * > types;
563 flatten( dcl->get_type(), back_inserter( types ) );
564 for ( Type * t : types ) {
565 // outermost const, volatile, _Atomic qualifiers in parameters should not play a role in the unification of function types, since they do not determine whether a function is callable.
566 // Note: MUST consider at least mutex qualifier, since functions can be overloaded on outermost mutex and a mutex function has different requirements than a non-mutex function.
567 t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic);
568
569 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
570 }
571 delete dcl;
572 }
573 }
574
575 void Unify::postvisit(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->parameters.size() == flatOther->parameters.size() && flatFunc->returnVals.size() == flatOther->returnVals.size()) || flatFunc->isTtype() || flatOther->isTtype() ) {
587 if ( unifyDeclList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
588 if ( unifyDeclList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->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->name == otherStruct->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->parameters;
615 std::list< Expression* > otherParams = ((RefType*)other)->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 assertf(param, "Aggregate parameters should be type expressions");
621 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
622 assertf(otherParam, "Aggregate parameters should be type expressions");
623
624 Type* paramTy = param->get_type();
625 Type* otherParamTy = otherParam->get_type();
626
627 bool tupleParam = Tuples::isTtype( paramTy );
628 bool otherTupleParam = Tuples::isTtype( otherParamTy );
629
630 if ( tupleParam && otherTupleParam ) {
631 ++it; ++jt; // skip ttype parameters for break
632 } else if ( tupleParam ) {
633 // bundle other parameters into tuple to match
634 std::list< Type * > binderTypes;
635
636 do {
637 binderTypes.push_back( otherParam->get_type()->clone() );
638 ++jt;
639
640 if ( jt == otherParams.end() ) break;
641
642 otherParam = dynamic_cast< TypeExpr* >(*jt);
643 assertf(otherParam, "Aggregate parameters should be type expressions");
644 } while (true);
645
646 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
647 ++it; // skip ttype parameter for break
648 } else if ( otherTupleParam ) {
649 // bundle parameters into tuple to match other
650 std::list< Type * > binderTypes;
651
652 do {
653 binderTypes.push_back( param->get_type()->clone() );
654 ++it;
655
656 if ( it == params.end() ) break;
657
658 param = dynamic_cast< TypeExpr* >(*it);
659 assertf(param, "Aggregate parameters should be type expressions");
660 } while (true);
661
662 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
663 ++jt; // skip ttype parameter for break
664 }
665
666 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
667 result = false;
668 return;
669 }
670
671 // ttype parameter should be last
672 if ( tupleParam || otherTupleParam ) break;
673 }
674 result = ( it == params.end() && jt == otherParams.end() );
675 }
676
677 void Unify::postvisit(StructInstType *structInst) {
678 handleGenericRefType( structInst, type2 );
679 }
680
681 void Unify::postvisit(UnionInstType *unionInst) {
682 handleGenericRefType( unionInst, type2 );
683 }
684
685 void Unify::postvisit(EnumInstType *enumInst) {
686 handleRefType( enumInst, type2 );
687 }
688
689 void Unify::postvisit(TraitInstType *contextInst) {
690 handleRefType( contextInst, type2 );
691 }
692
693 void Unify::postvisit(TypeInstType *typeInst) {
694 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
695 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
696 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
697 result = true;
698/// } else {
699/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
700/// if ( nt ) {
701/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
702/// assert( type );
703/// if ( type->get_base() ) {
704/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
705/// }
706/// }
707 } // if
708 }
709
710 template< typename Iterator1, typename Iterator2 >
711 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
712 auto get_type = [](Type * t) { return t; };
713 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
714 Type * t1 = *list1Begin;
715 Type * t2 = *list2Begin;
716 bool isTtype1 = Tuples::isTtype( t1 );
717 bool isTtype2 = Tuples::isTtype( t2 );
718 // xxx - assumes ttype must be last parameter
719 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
720 if ( isTtype1 && ! isTtype2 ) {
721 // combine all of the things in list2, then unify
722 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
723 } else if ( isTtype2 && ! isTtype1 ) {
724 // combine all of the things in list1, then unify
725 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
726 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
727 return false;
728 } // if
729
730 } // for
731 if ( list1Begin != list1End ) {
732 // try unifying empty tuple type with ttype
733 Type * t1 = *list1Begin;
734 if ( Tuples::isTtype( t1 ) ) {
735 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
736 } else return false;
737 } else if ( list2Begin != list2End ) {
738 // try unifying empty tuple type with ttype
739 Type * t2 = *list2Begin;
740 if ( Tuples::isTtype( t2 ) ) {
741 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
742 } else return false;
743 } else {
744 return true;
745 } // if
746 }
747
748 void Unify::postvisit(TupleType *tupleType) {
749 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
750 std::unique_ptr<TupleType> flat1( tupleType->clone() );
751 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
752 std::list<Type *> types1, types2;
753
754 PassVisitor<TtypeExpander> expander( env );
755 flat1->acceptMutator( expander );
756 flat2->acceptMutator( expander );
757
758 flatten( flat1.get(), back_inserter( types1 ) );
759 flatten( flat2.get(), back_inserter( types2 ) );
760
761 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
762 } // if
763 }
764
765 void Unify::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) {
766 result = dynamic_cast< VarArgsType* >( type2 );
767 }
768
769 void Unify::postvisit( __attribute__((unused)) ZeroType *zeroType ) {
770 result = dynamic_cast< ZeroType* >( type2 );
771 }
772
773 void Unify::postvisit( __attribute__((unused)) OneType *oneType ) {
774 result = dynamic_cast< OneType* >( type2 );
775 }
776
777 // xxx - compute once and store in the FunctionType?
778 Type * extractResultType( FunctionType * function ) {
779 if ( function->get_returnVals().size() == 0 ) {
780 return new VoidType( Type::Qualifiers() );
781 } else if ( function->get_returnVals().size() == 1 ) {
782 return function->get_returnVals().front()->get_type()->clone();
783 } else {
784 std::list< Type * > types;
785 for ( DeclarationWithType * decl : function->get_returnVals() ) {
786 types.push_back( decl->get_type()->clone() );
787 } // for
788 return new TupleType( Type::Qualifiers(), types );
789 }
790 }
791} // namespace ResolvExpr
792
793// Local Variables: //
794// tab-width: 4 //
795// mode: c++ //
796// compile-command: "make install" //
797// End: //
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