source: src/ResolvExpr/Unify.cc@ b45d4b2

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 b45d4b2 was aeef2bd, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

Fix unification of VLAs
  • Property mode set to 100644
File size: 32.9 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 class Unify : public Visitor {
47 public:
48 Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
49
50 bool get_result() const { return result; }
51 private:
52 virtual void visit(VoidType *voidType);
53 virtual void visit(BasicType *basicType);
54 virtual void visit(PointerType *pointerType);
55 virtual void visit(ArrayType *arrayType);
56 virtual void visit(ReferenceType *refType);
57 virtual void visit(FunctionType *functionType);
58 virtual void visit(StructInstType *aggregateUseType);
59 virtual void visit(UnionInstType *aggregateUseType);
60 virtual void visit(EnumInstType *aggregateUseType);
61 virtual void visit(TraitInstType *aggregateUseType);
62 virtual void visit(TypeInstType *aggregateUseType);
63 virtual void visit(TupleType *tupleType);
64 virtual void visit(VarArgsType *varArgsType);
65 virtual void visit(ZeroType *zeroType);
66 virtual void visit(OneType *oneType);
67
68 template< typename RefType > void handleRefType( RefType *inst, Type *other );
69 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
70
71 bool result;
72 Type *type2; // inherited
73 TypeEnvironment &env;
74 AssertionSet &needAssertions;
75 AssertionSet &haveAssertions;
76 const OpenVarSet &openVars;
77 WidenMode widenMode;
78 const SymTab::Indexer &indexer;
79 };
80
81 /// Attempts an inexact unification of type1 and type2.
82 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
83 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common );
84 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
85
86 bool typesCompatible( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
87 TypeEnvironment newEnv;
88 OpenVarSet openVars, closedVars; // added closedVars
89 AssertionSet needAssertions, haveAssertions;
90 Type *newFirst = first->clone(), *newSecond = second->clone();
91 env.apply( newFirst );
92 env.apply( newSecond );
93
94 // do we need to do this? Seems like we do, types should be able to be compatible if they
95 // have free variables that can unify
96 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
97 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
98
99 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
100 delete newFirst;
101 delete newSecond;
102 return result;
103 }
104
105 bool typesCompatibleIgnoreQualifiers( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
106 TypeEnvironment newEnv;
107 OpenVarSet openVars;
108 AssertionSet needAssertions, haveAssertions;
109 Type *newFirst = first->clone(), *newSecond = second->clone();
110 env.apply( newFirst );
111 env.apply( newSecond );
112 newFirst->get_qualifiers() = Type::Qualifiers();
113 newSecond->get_qualifiers() = Type::Qualifiers();
114/// std::cerr << "first is ";
115/// first->print( std::cerr );
116/// std::cerr << std::endl << "second is ";
117/// second->print( std::cerr );
118/// std::cerr << std::endl << "newFirst is ";
119/// newFirst->print( std::cerr );
120/// std::cerr << std::endl << "newSecond is ";
121/// newSecond->print( std::cerr );
122/// std::cerr << std::endl;
123 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
124 delete newFirst;
125 delete newSecond;
126 return result;
127 }
128
129 bool isFtype( Type *type ) {
130 if ( dynamic_cast< FunctionType* >( type ) ) {
131 return true;
132 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( type ) ) {
133 return typeInst->get_isFtype();
134 } // if
135 return false;
136 }
137
138 bool tyVarCompatible( const TypeDecl::Data & data, Type *type ) {
139 switch ( data.kind ) {
140 case TypeDecl::Any:
141 case TypeDecl::Dtype:
142 // to bind to an object type variable, the type must not be a function type.
143 // if the type variable is specified to be a complete type then the incoming
144 // type must also be complete
145 // xxx - should this also check that type is not a tuple type and that it's not a ttype?
146 return ! isFtype( type ) && (! data.isComplete || type->isComplete() );
147 case TypeDecl::Ftype:
148 return isFtype( type );
149 case TypeDecl::Ttype:
150 // ttype unifies with any tuple type
151 return dynamic_cast< TupleType * >( type ) || Tuples::isTtype( type );
152 } // switch
153 return false;
154 }
155
156 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 ) {
157 // remove references from other, so that type variables can only bind to value types
158 other = other->stripReferences();
159 OpenVarSet::const_iterator tyvar = openVars.find( typeInst->get_name() );
160 assert( tyvar != openVars.end() );
161 if ( ! tyVarCompatible( tyvar->second, other ) ) {
162 return false;
163 } // if
164 if ( occurs( other, typeInst->get_name(), env ) ) {
165 return false;
166 } // if
167 EqvClass curClass;
168 if ( env.lookup( typeInst->get_name(), curClass ) ) {
169 if ( curClass.type ) {
170 Type *common = 0;
171 // attempt to unify equivalence class type (which has qualifiers stripped, so they must be restored) with the type to bind to
172 std::unique_ptr< Type > newType( curClass.type->clone() );
173 newType->get_qualifiers() = typeInst->get_qualifiers();
174 if ( unifyInexact( newType.get(), other, env, needAssertions, haveAssertions, openVars, widenMode & WidenMode( curClass.allowWidening, true ), indexer, common ) ) {
175 if ( common ) {
176 common->get_qualifiers() = Type::Qualifiers();
177 delete curClass.type;
178 curClass.type = common;
179 env.add( curClass );
180 } // if
181 return true;
182 } else {
183 return false;
184 } // if
185 } else {
186 curClass.type = other->clone();
187 curClass.type->get_qualifiers() = Type::Qualifiers();
188 curClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
189 env.add( curClass );
190 } // if
191 } else {
192 EqvClass newClass;
193 newClass.vars.insert( typeInst->get_name() );
194 newClass.type = other->clone();
195 newClass.type->get_qualifiers() = Type::Qualifiers();
196 newClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
197 newClass.data = data;
198 env.add( newClass );
199 } // if
200 return true;
201 }
202
203 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 ) {
204 bool result = true;
205 EqvClass class1, class2;
206 bool hasClass1 = false, hasClass2 = false;
207 bool widen1 = false, widen2 = false;
208 Type *type1 = 0, *type2 = 0;
209
210 if ( env.lookup( var1->get_name(), class1 ) ) {
211 hasClass1 = true;
212 if ( class1.type ) {
213 if ( occurs( class1.type, var2->get_name(), env ) ) {
214 return false;
215 } // if
216 type1 = class1.type->clone();
217 } // if
218 widen1 = widenMode.widenFirst && class1.allowWidening;
219 } // if
220 if ( env.lookup( var2->get_name(), class2 ) ) {
221 hasClass2 = true;
222 if ( class2.type ) {
223 if ( occurs( class2.type, var1->get_name(), env ) ) {
224 return false;
225 } // if
226 type2 = class2.type->clone();
227 } // if
228 widen2 = widenMode.widenSecond && class2.allowWidening;
229 } // if
230
231 if ( type1 && type2 ) {
232// std::cerr << "has type1 && type2" << std::endl;
233 WidenMode newWidenMode ( widen1, widen2 );
234 Type *common = 0;
235 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, newWidenMode, indexer, common ) ) {
236 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
237 class1.allowWidening = widen1 && widen2;
238 if ( common ) {
239 common->get_qualifiers() = Type::Qualifiers();
240 delete class1.type;
241 class1.type = common;
242 } // if
243 env.add( class1 );
244 } else {
245 result = false;
246 } // if
247 } else if ( hasClass1 && hasClass2 ) {
248 if ( type1 ) {
249 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
250 class1.allowWidening = widen1;
251 env.add( class1 );
252 } else {
253 class2.vars.insert( class1.vars.begin(), class1.vars.end() );
254 class2.allowWidening = widen2;
255 env.add( class2 );
256 } // if
257 } else if ( hasClass1 ) {
258 class1.vars.insert( var2->get_name() );
259 class1.allowWidening = widen1;
260 env.add( class1 );
261 } else if ( hasClass2 ) {
262 class2.vars.insert( var1->get_name() );
263 class2.allowWidening = widen2;
264 env.add( class2 );
265 } else {
266 EqvClass newClass;
267 newClass.vars.insert( var1->get_name() );
268 newClass.vars.insert( var2->get_name() );
269 newClass.allowWidening = widen1 && widen2;
270 newClass.data = data;
271 env.add( newClass );
272 } // if
273 delete type1;
274 delete type2;
275 return result;
276 }
277
278 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
279 OpenVarSet closedVars;
280 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
281 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
282 Type *commonType = 0;
283 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
284 if ( commonType ) {
285 delete commonType;
286 } // if
287 return true;
288 } else {
289 return false;
290 } // if
291 }
292
293 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
294 OpenVarSet closedVars;
295 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
296 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
297 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
298 }
299
300 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
301#ifdef DEBUG
302 TypeEnvironment debugEnv( env );
303#endif
304 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
305 return false;
306 }
307
308 bool result;
309 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
310 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
311 OpenVarSet::const_iterator entry1, entry2;
312 if ( var1 ) {
313 entry1 = openVars.find( var1->get_name() );
314 } // if
315 if ( var2 ) {
316 entry2 = openVars.find( var2->get_name() );
317 } // if
318 bool isopen1 = var1 && ( entry1 != openVars.end() );
319 bool isopen2 = var2 && ( entry2 != openVars.end() );
320
321 if ( isopen1 && isopen2 && entry1->second == entry2->second ) {
322 result = bindVarToVar( var1, var2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
323 } else if ( isopen1 ) {
324 result = bindVar( var1, type2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
325 } else if ( isopen2 ) {
326 result = bindVar( var2, type1, entry2->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
327 } else {
328 Unify comparator( type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
329 type1->accept( comparator );
330 result = comparator.get_result();
331 } // if
332#ifdef DEBUG
333 std::cerr << "============ unifyExact" << std::endl;
334 std::cerr << "type1 is ";
335 type1->print( std::cerr );
336 std::cerr << std::endl << "type2 is ";
337 type2->print( std::cerr );
338 std::cerr << std::endl << "openVars are ";
339 printOpenVarSet( openVars, std::cerr, 8 );
340 std::cerr << std::endl << "input env is " << std::endl;
341 debugEnv.print( std::cerr, 8 );
342 std::cerr << std::endl << "result env is " << std::endl;
343 env.print( std::cerr, 8 );
344 std::cerr << "result is " << result << std::endl;
345#endif
346 return result;
347 }
348
349 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
350 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
351 }
352
353 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common ) {
354 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
355 type1->get_qualifiers() = Type::Qualifiers();
356 type2->get_qualifiers() = Type::Qualifiers();
357 bool result;
358#ifdef DEBUG
359 std::cerr << "unifyInexact type 1 is ";
360 type1->print( std::cerr );
361 std::cerr << " type 2 is ";
362 type2->print( std::cerr );
363 std::cerr << std::endl;
364#endif
365 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer ) ) {
366#ifdef DEBUG
367 std::cerr << "unifyInexact: no exact unification found" << std::endl;
368#endif
369 if ( ( common = commonType( type1, type2, widenMode.widenFirst, widenMode.widenSecond, indexer, env, openVars ) ) ) {
370 common->get_qualifiers() = tq1 | tq2;
371#ifdef DEBUG
372 std::cerr << "unifyInexact: common type is ";
373 common->print( std::cerr );
374 std::cerr << std::endl;
375#endif
376 result = true;
377 } else {
378#ifdef DEBUG
379 std::cerr << "unifyInexact: no common type found" << std::endl;
380#endif
381 result = false;
382 } // if
383 } else {
384 if ( tq1 != tq2 ) {
385 if ( ( tq1 > tq2 || widenMode.widenFirst ) && ( tq2 > tq1 || widenMode.widenSecond ) ) {
386 common = type1->clone();
387 common->get_qualifiers() = tq1 | tq2;
388 result = true;
389 } else {
390 result = false;
391 } // if
392 } else {
393 common = type1->clone();
394 common->get_qualifiers() = tq1 | tq2;
395 result = true;
396 } // if
397 } // if
398 type1->get_qualifiers() = tq1;
399 type2->get_qualifiers() = tq2;
400 return result;
401 }
402
403 Unify::Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer )
404 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widenMode( widenMode ), indexer( indexer ) {
405 }
406
407 void Unify::visit( __attribute__((unused)) VoidType *voidType) {
408 result = dynamic_cast< VoidType* >( type2 );
409 }
410
411 void Unify::visit(BasicType *basicType) {
412 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
413 result = basicType->get_kind() == otherBasic->get_kind();
414 } // if
415 }
416
417 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
418/// std::cerr << "assertion set is" << std::endl;
419/// printAssertionSet( assertions, std::cerr, 8 );
420/// std::cerr << "looking for ";
421/// assert->print( std::cerr );
422/// std::cerr << std::endl;
423 AssertionSet::iterator i = assertions.find( assert );
424 if ( i != assertions.end() ) {
425/// std::cerr << "found it!" << std::endl;
426 i->second.isUsed = true;
427 } // if
428 }
429
430 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
431 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
432 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
433 markAssertionSet( assertion1, *assert );
434 markAssertionSet( assertion2, *assert );
435 } // for
436 } // for
437 }
438
439 void Unify::visit(PointerType *pointerType) {
440 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
441 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
442 markAssertions( haveAssertions, needAssertions, pointerType );
443 markAssertions( haveAssertions, needAssertions, otherPointer );
444 } // if
445 }
446
447 void Unify::visit(ReferenceType *refType) {
448 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
449 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
450 markAssertions( haveAssertions, needAssertions, refType );
451 markAssertions( haveAssertions, needAssertions, otherRef );
452 } // if
453 }
454
455 void Unify::visit(ArrayType *arrayType) {
456 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
457 // to unify, array types must both be VLA or both not VLA
458 // and must both have a dimension expression or not have a dimension
459 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
460
461 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
462 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
463 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
464 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
465 // see C11 Reference Manual 6.7.6.2.6
466 // two array types with size specifiers that are integer constant expressions are
467 // compatible if both size specifiers have the same constant value
468 if ( ce1 && ce2 ) {
469 Constant * c1 = ce1->get_constant();
470 Constant * c2 = ce2->get_constant();
471
472 if ( c1->get_value() != c2->get_value() ) {
473 // does not unify if the dimension is different
474 return;
475 }
476 }
477 }
478
479 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
480 } // if
481 }
482
483 template< typename Iterator, typename Func >
484 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
485 std::list< Type * > types;
486 for ( ; begin != end; ++begin ) {
487 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
488 flatten( toType( *begin ), back_inserter( types ) );
489 }
490 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
491 }
492
493 template< typename Iterator1, typename Iterator2 >
494 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
495 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
496 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
497 Type * t1 = (*list1Begin)->get_type();
498 Type * t2 = (*list2Begin)->get_type();
499 bool isTtype1 = Tuples::isTtype( t1 );
500 bool isTtype2 = Tuples::isTtype( t2 );
501 // xxx - assumes ttype must be last parameter
502 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
503 if ( isTtype1 && ! isTtype2 ) {
504 // combine all of the things in list2, then unify
505 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
506 } else if ( isTtype2 && ! isTtype1 ) {
507 // combine all of the things in list1, then unify
508 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
509 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
510 return false;
511 } // if
512 } // for
513 // 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
514 if ( list1Begin != list1End ) {
515 // try unifying empty tuple type with ttype
516 Type * t1 = (*list1Begin)->get_type();
517 if ( Tuples::isTtype( t1 ) ) {
518 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
519 } else return false;
520 } else if ( list2Begin != list2End ) {
521 // try unifying empty tuple type with ttype
522 Type * t2 = (*list2Begin)->get_type();
523 if ( Tuples::isTtype( t2 ) ) {
524 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
525 } else return false;
526 } else {
527 return true;
528 } // if
529 }
530
531 /// Finds ttypes and replaces them with their expansion, if known.
532 /// This needs to be done so that satisfying ttype assertions is easier.
533 /// If this isn't done then argument lists can have wildly different
534 /// size and structure, when they should be compatible.
535 struct TtypeExpander : public WithShortCircuiting {
536 TypeEnvironment & tenv;
537 TtypeExpander( TypeEnvironment & tenv ) : tenv( tenv ) {}
538 void premutate( TypeInstType * ) { visit_children = false; }
539 Type * postmutate( TypeInstType * typeInst ) {
540 EqvClass eqvClass;
541 if ( tenv.lookup( typeInst->get_name(), eqvClass ) ) {
542 if ( eqvClass.data.kind == TypeDecl::Ttype ) {
543 // expand ttype parameter into its actual type
544 if ( eqvClass.type ) {
545 delete typeInst;
546 return eqvClass.type->clone();
547 }
548 }
549 }
550 return typeInst;
551 }
552 };
553
554 /// flattens a list of declarations, so that each tuple type has a single declaration.
555 /// makes use of TtypeExpander to ensure ttypes are flat as well.
556 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
557 dst.clear();
558 for ( DeclarationWithType * dcl : src ) {
559 PassVisitor<TtypeExpander> expander( env );
560 dcl->acceptMutator( expander );
561 std::list< Type * > types;
562 flatten( dcl->get_type(), back_inserter( types ) );
563 for ( Type * t : types ) {
564 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
565 }
566 delete dcl;
567 }
568 }
569
570 void Unify::visit(FunctionType *functionType) {
571 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
572 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
573 // flatten the parameter lists for both functions so that tuple structure
574 // doesn't affect unification. Must be a clone so that the types don't change.
575 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
576 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
577 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
578 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
579
580 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
581 if ( (flatFunc->get_parameters().size() == flatOther->get_parameters().size() && flatFunc->get_returnVals().size() == flatOther->get_returnVals().size()) || flatFunc->isTtype() || flatOther->isTtype() ) {
582 if ( unifyDeclList( flatFunc->get_parameters().begin(), flatFunc->get_parameters().end(), flatOther->get_parameters().begin(), flatOther->get_parameters().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
583 if ( unifyDeclList( flatFunc->get_returnVals().begin(), flatFunc->get_returnVals().end(), flatOther->get_returnVals().begin(), flatOther->get_returnVals().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
584
585 // the original types must be used in mark assertions, since pointer comparisons are used
586 markAssertions( haveAssertions, needAssertions, functionType );
587 markAssertions( haveAssertions, needAssertions, otherFunction );
588
589 result = true;
590 } // if
591 } // if
592 } // if
593 } // if
594 }
595
596 template< typename RefType >
597 void Unify::handleRefType( RefType *inst, Type *other ) {
598 // check that other type is compatible and named the same
599 RefType *otherStruct = dynamic_cast< RefType* >( other );
600 result = otherStruct && inst->get_name() == otherStruct->get_name();
601 }
602
603 template< typename RefType >
604 void Unify::handleGenericRefType( RefType *inst, Type *other ) {
605 // Check that other type is compatible and named the same
606 handleRefType( inst, other );
607 if ( ! result ) return;
608 // Check that parameters of types unify, if any
609 std::list< Expression* > params = inst->get_parameters();
610 std::list< Expression* > otherParams = ((RefType*)other)->get_parameters();
611
612 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
613 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
614 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
615 assertf(param, "Aggregate parameters should be type expressions");
616 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
617 assertf(otherParam, "Aggregate parameters should be type expressions");
618
619 Type* paramTy = param->get_type();
620 Type* otherParamTy = otherParam->get_type();
621
622 bool tupleParam = Tuples::isTtype( paramTy );
623 bool otherTupleParam = Tuples::isTtype( otherParamTy );
624
625 if ( tupleParam && otherTupleParam ) {
626 ++it; ++jt; // skip ttype parameters for break
627 } else if ( tupleParam ) {
628 // bundle other parameters into tuple to match
629 std::list< Type * > binderTypes;
630
631 do {
632 binderTypes.push_back( otherParam->get_type()->clone() );
633 ++jt;
634
635 if ( jt == otherParams.end() ) break;
636
637 otherParam = dynamic_cast< TypeExpr* >(*jt);
638 assertf(otherParam, "Aggregate parameters should be type expressions");
639 } while (true);
640
641 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
642 ++it; // skip ttype parameter for break
643 } else if ( otherTupleParam ) {
644 // bundle parameters into tuple to match other
645 std::list< Type * > binderTypes;
646
647 do {
648 binderTypes.push_back( param->get_type()->clone() );
649 ++it;
650
651 if ( it == params.end() ) break;
652
653 param = dynamic_cast< TypeExpr* >(*it);
654 assertf(param, "Aggregate parameters should be type expressions");
655 } while (true);
656
657 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
658 ++jt; // skip ttype parameter for break
659 }
660
661 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
662 result = false;
663 return;
664 }
665
666 // ttype parameter should be last
667 if ( tupleParam || otherTupleParam ) break;
668 }
669 result = ( it == params.end() && jt == otherParams.end() );
670 }
671
672 void Unify::visit(StructInstType *structInst) {
673 handleGenericRefType( structInst, type2 );
674 }
675
676 void Unify::visit(UnionInstType *unionInst) {
677 handleGenericRefType( unionInst, type2 );
678 }
679
680 void Unify::visit(EnumInstType *enumInst) {
681 handleRefType( enumInst, type2 );
682 }
683
684 void Unify::visit(TraitInstType *contextInst) {
685 handleRefType( contextInst, type2 );
686 }
687
688 void Unify::visit(TypeInstType *typeInst) {
689 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
690 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
691 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
692 result = true;
693/// } else {
694/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
695/// if ( nt ) {
696/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
697/// assert( type );
698/// if ( type->get_base() ) {
699/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
700/// }
701/// }
702 } // if
703 }
704
705 template< typename Iterator1, typename Iterator2 >
706 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
707 auto get_type = [](Type * t) { return t; };
708 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
709 Type * t1 = *list1Begin;
710 Type * t2 = *list2Begin;
711 bool isTtype1 = Tuples::isTtype( t1 );
712 bool isTtype2 = Tuples::isTtype( t2 );
713 // xxx - assumes ttype must be last parameter
714 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
715 if ( isTtype1 && ! isTtype2 ) {
716 // combine all of the things in list2, then unify
717 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
718 } else if ( isTtype2 && ! isTtype1 ) {
719 // combine all of the things in list1, then unify
720 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
721 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
722 return false;
723 } // if
724
725 } // for
726 if ( list1Begin != list1End ) {
727 // try unifying empty tuple type with ttype
728 Type * t1 = *list1Begin;
729 if ( Tuples::isTtype( t1 ) ) {
730 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
731 } else return false;
732 } else if ( list2Begin != list2End ) {
733 // try unifying empty tuple type with ttype
734 Type * t2 = *list2Begin;
735 if ( Tuples::isTtype( t2 ) ) {
736 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
737 } else return false;
738 } else {
739 return true;
740 } // if
741 }
742
743 void Unify::visit(TupleType *tupleType) {
744 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
745 std::unique_ptr<TupleType> flat1( tupleType->clone() );
746 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
747 std::list<Type *> types1, types2;
748
749 PassVisitor<TtypeExpander> expander( env );
750 flat1->acceptMutator( expander );
751 flat2->acceptMutator( expander );
752
753 flatten( flat1.get(), back_inserter( types1 ) );
754 flatten( flat2.get(), back_inserter( types2 ) );
755
756 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
757 } // if
758 }
759
760 void Unify::visit( __attribute__((unused)) VarArgsType *varArgsType ) {
761 result = dynamic_cast< VarArgsType* >( type2 );
762 }
763
764 void Unify::visit( __attribute__((unused)) ZeroType *zeroType ) {
765 result = dynamic_cast< ZeroType* >( type2 );
766 }
767
768 void Unify::visit( __attribute__((unused)) OneType *oneType ) {
769 result = dynamic_cast< OneType* >( type2 );
770 }
771
772 // xxx - compute once and store in the FunctionType?
773 Type * extractResultType( FunctionType * function ) {
774 if ( function->get_returnVals().size() == 0 ) {
775 return new VoidType( Type::Qualifiers() );
776 } else if ( function->get_returnVals().size() == 1 ) {
777 return function->get_returnVals().front()->get_type()->clone();
778 } else {
779 std::list< Type * > types;
780 for ( DeclarationWithType * decl : function->get_returnVals() ) {
781 types.push_back( decl->get_type()->clone() );
782 } // for
783 return new TupleType( Type::Qualifiers(), types );
784 }
785 }
786} // namespace ResolvExpr
787
788// Local Variables: //
789// tab-width: 4 //
790// mode: c++ //
791// compile-command: "make install" //
792// End: //
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