source: src/ResolvExpr/Unify.cc@ c93bc28

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 c93bc28 was 36a5a77, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

Strip references when binding type variables
  • Property mode set to 100644
File size: 32.0 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 <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(ReferenceType *refType);
45 virtual void visit(FunctionType *functionType);
46 virtual void visit(StructInstType *aggregateUseType);
47 virtual void visit(UnionInstType *aggregateUseType);
48 virtual void visit(EnumInstType *aggregateUseType);
49 virtual void visit(TraitInstType *aggregateUseType);
50 virtual void visit(TypeInstType *aggregateUseType);
51 virtual void visit(TupleType *tupleType);
52 virtual void visit(VarArgsType *varArgsType);
53 virtual void visit(ZeroType *zeroType);
54 virtual void visit(OneType *oneType);
55
56 template< typename RefType > void handleRefType( RefType *inst, Type *other );
57 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
58
59 bool result;
60 Type *type2; // inherited
61 TypeEnvironment &env;
62 AssertionSet &needAssertions;
63 AssertionSet &haveAssertions;
64 const OpenVarSet &openVars;
65 WidenMode widenMode;
66 const SymTab::Indexer &indexer;
67 };
68
69 /// Attempts an inexact unification of type1 and type2.
70 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
71 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common );
72 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
73
74 bool typesCompatible( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
75 TypeEnvironment newEnv;
76 OpenVarSet openVars, closedVars; // added closedVars
77 AssertionSet needAssertions, haveAssertions;
78 Type *newFirst = first->clone(), *newSecond = second->clone();
79 env.apply( newFirst );
80 env.apply( newSecond );
81
82 // do we need to do this? Seems like we do, types should be able to be compatible if they
83 // have free variables that can unify
84 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
85 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
86
87 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
88 delete newFirst;
89 delete newSecond;
90 return result;
91 }
92
93 bool typesCompatibleIgnoreQualifiers( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
94 TypeEnvironment newEnv;
95 OpenVarSet openVars;
96 AssertionSet needAssertions, haveAssertions;
97 Type *newFirst = first->clone(), *newSecond = second->clone();
98 env.apply( newFirst );
99 env.apply( newSecond );
100 newFirst->get_qualifiers() = Type::Qualifiers();
101 newSecond->get_qualifiers() = Type::Qualifiers();
102/// std::cerr << "first is ";
103/// first->print( std::cerr );
104/// std::cerr << std::endl << "second is ";
105/// second->print( std::cerr );
106/// std::cerr << std::endl << "newFirst is ";
107/// newFirst->print( std::cerr );
108/// std::cerr << std::endl << "newSecond is ";
109/// newSecond->print( std::cerr );
110/// std::cerr << std::endl;
111 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
112 delete newFirst;
113 delete newSecond;
114 return result;
115 }
116
117 bool isFtype( Type *type ) {
118 if ( dynamic_cast< FunctionType* >( type ) ) {
119 return true;
120 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( type ) ) {
121 return typeInst->get_isFtype();
122 } // if
123 return false;
124 }
125
126 bool tyVarCompatible( const TypeDecl::Data & data, Type *type ) {
127 switch ( data.kind ) {
128 case TypeDecl::Any:
129 case TypeDecl::Dtype:
130 // to bind to an object type variable, the type must not be a function type.
131 // if the type variable is specified to be a complete type then the incoming
132 // type must also be complete
133 // xxx - should this also check that type is not a tuple type and that it's not a ttype?
134 return ! isFtype( type ) && (! data.isComplete || type->isComplete() );
135 case TypeDecl::Ftype:
136 return isFtype( type );
137 case TypeDecl::Ttype:
138 // ttype unifies with any tuple type
139 return dynamic_cast< TupleType * >( type ) || Tuples::isTtype( type );
140 } // switch
141 return false;
142 }
143
144 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 ) {
145 // remove references from other, so that type variables can only bind to value types
146 other = other->stripReferences();
147 OpenVarSet::const_iterator tyvar = openVars.find( typeInst->get_name() );
148 assert( tyvar != openVars.end() );
149 if ( ! tyVarCompatible( tyvar->second, other ) ) {
150 return false;
151 } // if
152 if ( occurs( other, typeInst->get_name(), env ) ) {
153 return false;
154 } // if
155 EqvClass curClass;
156 if ( env.lookup( typeInst->get_name(), curClass ) ) {
157 if ( curClass.type ) {
158 Type *common = 0;
159 // attempt to unify equivalence class type (which has qualifiers stripped, so they must be restored) with the type to bind to
160 std::auto_ptr< Type > newType( curClass.type->clone() );
161 newType->get_qualifiers() = typeInst->get_qualifiers();
162 if ( unifyInexact( newType.get(), other, env, needAssertions, haveAssertions, openVars, widenMode & WidenMode( curClass.allowWidening, true ), indexer, common ) ) {
163 if ( common ) {
164 common->get_qualifiers() = Type::Qualifiers();
165 delete curClass.type;
166 curClass.type = common;
167 env.add( curClass );
168 } // if
169 return true;
170 } else {
171 return false;
172 } // if
173 } else {
174 curClass.type = other->clone();
175 curClass.type->get_qualifiers() = Type::Qualifiers();
176 curClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
177 env.add( curClass );
178 } // if
179 } else {
180 EqvClass newClass;
181 newClass.vars.insert( typeInst->get_name() );
182 newClass.type = other->clone();
183 newClass.type->get_qualifiers() = Type::Qualifiers();
184 newClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
185 newClass.data = data;
186 env.add( newClass );
187 } // if
188 return true;
189 }
190
191 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 ) {
192 bool result = true;
193 EqvClass class1, class2;
194 bool hasClass1 = false, hasClass2 = false;
195 bool widen1 = false, widen2 = false;
196 Type *type1 = 0, *type2 = 0;
197
198 if ( env.lookup( var1->get_name(), class1 ) ) {
199 hasClass1 = true;
200 if ( class1.type ) {
201 if ( occurs( class1.type, var2->get_name(), env ) ) {
202 return false;
203 } // if
204 type1 = class1.type->clone();
205 } // if
206 widen1 = widenMode.widenFirst && class1.allowWidening;
207 } // if
208 if ( env.lookup( var2->get_name(), class2 ) ) {
209 hasClass2 = true;
210 if ( class2.type ) {
211 if ( occurs( class2.type, var1->get_name(), env ) ) {
212 return false;
213 } // if
214 type2 = class2.type->clone();
215 } // if
216 widen2 = widenMode.widenSecond && class2.allowWidening;
217 } // if
218
219 if ( type1 && type2 ) {
220// std::cerr << "has type1 && type2" << std::endl;
221 WidenMode newWidenMode ( widen1, widen2 );
222 Type *common = 0;
223 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, newWidenMode, indexer, common ) ) {
224 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
225 class1.allowWidening = widen1 && widen2;
226 if ( common ) {
227 common->get_qualifiers() = Type::Qualifiers();
228 delete class1.type;
229 class1.type = common;
230 } // if
231 env.add( class1 );
232 } else {
233 result = false;
234 } // if
235 } else if ( hasClass1 && hasClass2 ) {
236 if ( type1 ) {
237 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
238 class1.allowWidening = widen1;
239 env.add( class1 );
240 } else {
241 class2.vars.insert( class1.vars.begin(), class1.vars.end() );
242 class2.allowWidening = widen2;
243 env.add( class2 );
244 } // if
245 } else if ( hasClass1 ) {
246 class1.vars.insert( var2->get_name() );
247 class1.allowWidening = widen1;
248 env.add( class1 );
249 } else if ( hasClass2 ) {
250 class2.vars.insert( var1->get_name() );
251 class2.allowWidening = widen2;
252 env.add( class2 );
253 } else {
254 EqvClass newClass;
255 newClass.vars.insert( var1->get_name() );
256 newClass.vars.insert( var2->get_name() );
257 newClass.allowWidening = widen1 && widen2;
258 newClass.data = data;
259 env.add( newClass );
260 } // if
261 delete type1;
262 delete type2;
263 return result;
264 }
265
266 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
267 OpenVarSet closedVars;
268 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
269 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
270 Type *commonType = 0;
271 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
272 if ( commonType ) {
273 delete commonType;
274 } // if
275 return true;
276 } else {
277 return false;
278 } // if
279 }
280
281 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
282 OpenVarSet closedVars;
283 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
284 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
285 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
286 }
287
288 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
289#ifdef DEBUG
290 TypeEnvironment debugEnv( env );
291#endif
292 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
293 return false;
294 }
295
296 bool result;
297 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
298 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
299 OpenVarSet::const_iterator entry1, entry2;
300 if ( var1 ) {
301 entry1 = openVars.find( var1->get_name() );
302 } // if
303 if ( var2 ) {
304 entry2 = openVars.find( var2->get_name() );
305 } // if
306 bool isopen1 = var1 && ( entry1 != openVars.end() );
307 bool isopen2 = var2 && ( entry2 != openVars.end() );
308
309 if ( isopen1 && isopen2 && entry1->second == entry2->second ) {
310 result = bindVarToVar( var1, var2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
311 } else if ( isopen1 ) {
312 result = bindVar( var1, type2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
313 } else if ( isopen2 ) {
314 result = bindVar( var2, type1, entry2->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
315 } else {
316 Unify comparator( type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
317 type1->accept( comparator );
318 result = comparator.get_result();
319 } // if
320#ifdef DEBUG
321 std::cerr << "============ unifyExact" << std::endl;
322 std::cerr << "type1 is ";
323 type1->print( std::cerr );
324 std::cerr << std::endl << "type2 is ";
325 type2->print( std::cerr );
326 std::cerr << std::endl << "openVars are ";
327 printOpenVarSet( openVars, std::cerr, 8 );
328 std::cerr << std::endl << "input env is " << std::endl;
329 debugEnv.print( std::cerr, 8 );
330 std::cerr << std::endl << "result env is " << std::endl;
331 env.print( std::cerr, 8 );
332 std::cerr << "result is " << result << std::endl;
333#endif
334 return result;
335 }
336
337 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
338 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
339 }
340
341 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common ) {
342 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
343 type1->get_qualifiers() = Type::Qualifiers();
344 type2->get_qualifiers() = Type::Qualifiers();
345 bool result;
346#ifdef DEBUG
347 std::cerr << "unifyInexact type 1 is ";
348 type1->print( std::cerr );
349 std::cerr << " type 2 is ";
350 type2->print( std::cerr );
351 std::cerr << std::endl;
352#endif
353 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer ) ) {
354#ifdef DEBUG
355 std::cerr << "unifyInexact: no exact unification found" << std::endl;
356#endif
357 if ( ( common = commonType( type1, type2, widenMode.widenFirst, widenMode.widenSecond, indexer, env, openVars ) ) ) {
358 common->get_qualifiers() = tq1 | tq2;
359#ifdef DEBUG
360 std::cerr << "unifyInexact: common type is ";
361 common->print( std::cerr );
362 std::cerr << std::endl;
363#endif
364 result = true;
365 } else {
366#ifdef DEBUG
367 std::cerr << "unifyInexact: no common type found" << std::endl;
368#endif
369 result = false;
370 } // if
371 } else {
372 if ( tq1 != tq2 ) {
373 if ( ( tq1 > tq2 || widenMode.widenFirst ) && ( tq2 > tq1 || widenMode.widenSecond ) ) {
374 common = type1->clone();
375 common->get_qualifiers() = tq1 | tq2;
376 result = true;
377 } else {
378 result = false;
379 } // if
380 } else {
381 common = type1->clone();
382 common->get_qualifiers() = tq1 | tq2;
383 result = true;
384 } // if
385 } // if
386 type1->get_qualifiers() = tq1;
387 type2->get_qualifiers() = tq2;
388 return result;
389 }
390
391 Unify::Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer )
392 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widenMode( widenMode ), indexer( indexer ) {
393 }
394
395 void Unify::visit( __attribute__((unused)) VoidType *voidType) {
396 result = dynamic_cast< VoidType* >( type2 );
397 }
398
399 void Unify::visit(BasicType *basicType) {
400 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
401 result = basicType->get_kind() == otherBasic->get_kind();
402 } // if
403 }
404
405 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
406/// std::cerr << "assertion set is" << std::endl;
407/// printAssertionSet( assertions, std::cerr, 8 );
408/// std::cerr << "looking for ";
409/// assert->print( std::cerr );
410/// std::cerr << std::endl;
411 AssertionSet::iterator i = assertions.find( assert );
412 if ( i != assertions.end() ) {
413/// std::cerr << "found it!" << std::endl;
414 i->second.isUsed = true;
415 } // if
416 }
417
418 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
419 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
420 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
421 markAssertionSet( assertion1, *assert );
422 markAssertionSet( assertion2, *assert );
423 } // for
424 } // for
425 }
426
427 void Unify::visit(PointerType *pointerType) {
428 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
429 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
430 markAssertions( haveAssertions, needAssertions, pointerType );
431 markAssertions( haveAssertions, needAssertions, otherPointer );
432 } // if
433 }
434
435 void Unify::visit(ReferenceType *refType) {
436 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
437 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
438 markAssertions( haveAssertions, needAssertions, refType );
439 markAssertions( haveAssertions, needAssertions, otherRef );
440 } // if
441 }
442
443 void Unify::visit(ArrayType *arrayType) {
444 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
445 // to unify, array types must both be VLA or both not VLA
446 // and must both have a dimension expression or not have a dimension
447 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
448
449 // not positive this is correct in all cases, but it's needed for typedefs
450 if ( arrayType->get_isVarLen() || otherArray->get_isVarLen() ) {
451 return;
452 }
453
454 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
455 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
456 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
457 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
458 // see C11 Reference Manual 6.7.6.2.6
459 // two array types with size specifiers that are integer constant expressions are
460 // compatible if both size specifiers have the same constant value
461 if ( ce1 && ce2 ) {
462 Constant * c1 = ce1->get_constant();
463 Constant * c2 = ce2->get_constant();
464
465 if ( c1->get_value() != c2->get_value() ) {
466 // does not unify if the dimension is different
467 return;
468 }
469 }
470 }
471
472 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
473 } // if
474 }
475
476 template< typename Iterator, typename Func >
477 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
478 std::list< Type * > types;
479 for ( ; begin != end; ++begin ) {
480 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
481 flatten( toType( *begin ), back_inserter( types ) );
482 }
483 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
484 }
485
486 template< typename Iterator1, typename Iterator2 >
487 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
488 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
489 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
490 Type * t1 = (*list1Begin)->get_type();
491 Type * t2 = (*list2Begin)->get_type();
492 bool isTtype1 = Tuples::isTtype( t1 );
493 bool isTtype2 = Tuples::isTtype( t2 );
494 // xxx - assumes ttype must be last parameter
495 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
496 if ( isTtype1 && ! isTtype2 ) {
497 // combine all of the things in list2, then unify
498 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
499 } else if ( isTtype2 && ! isTtype1 ) {
500 // combine all of the things in list1, then unify
501 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
502 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
503 return false;
504 } // if
505 } // for
506 // 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
507 if ( list1Begin != list1End ) {
508 // try unifying empty tuple type with ttype
509 Type * t1 = (*list1Begin)->get_type();
510 if ( Tuples::isTtype( t1 ) ) {
511 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
512 } else return false;
513 } else if ( list2Begin != list2End ) {
514 // try unifying empty tuple type with ttype
515 Type * t2 = (*list2Begin)->get_type();
516 if ( Tuples::isTtype( t2 ) ) {
517 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
518 } else return false;
519 } else {
520 return true;
521 } // if
522 }
523
524 /// Finds ttypes and replaces them with their expansion, if known.
525 /// This needs to be done so that satisfying ttype assertions is easier.
526 /// If this isn't done then argument lists can have wildly different
527 /// size and structure, when they should be compatible.
528 struct TtypeExpander : public Mutator {
529 TypeEnvironment & env;
530 TtypeExpander( TypeEnvironment & env ) : env( env ) {}
531 Type * mutate( TypeInstType * typeInst ) {
532 EqvClass eqvClass;
533 if ( env.lookup( typeInst->get_name(), eqvClass ) ) {
534 if ( eqvClass.data.kind == TypeDecl::Ttype ) {
535 // expand ttype parameter into its actual type
536 if ( eqvClass.type ) {
537 delete typeInst;
538 return eqvClass.type->clone();
539 }
540 }
541 }
542 return typeInst;
543 }
544 };
545
546 /// flattens a list of declarations, so that each tuple type has a single declaration.
547 /// makes use of TtypeExpander to ensure ttypes are flat as well.
548 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
549 dst.clear();
550 for ( DeclarationWithType * dcl : src ) {
551 TtypeExpander expander( env );
552 dcl->acceptMutator( expander );
553 std::list< Type * > types;
554 flatten( dcl->get_type(), back_inserter( types ) );
555 for ( Type * t : types ) {
556 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
557 }
558 delete dcl;
559 }
560 }
561
562 void Unify::visit(FunctionType *functionType) {
563 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
564 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
565 // flatten the parameter lists for both functions so that tuple structure
566 // doesn't affect unification. Must be a clone so that the types don't change.
567 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
568 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
569 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
570 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
571
572 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
573 if ( (flatFunc->get_parameters().size() == flatOther->get_parameters().size() && flatFunc->get_returnVals().size() == flatOther->get_returnVals().size()) || flatFunc->isTtype() || flatOther->isTtype() ) {
574 if ( unifyDeclList( flatFunc->get_parameters().begin(), flatFunc->get_parameters().end(), flatOther->get_parameters().begin(), flatOther->get_parameters().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
575 if ( unifyDeclList( flatFunc->get_returnVals().begin(), flatFunc->get_returnVals().end(), flatOther->get_returnVals().begin(), flatOther->get_returnVals().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
576
577 // the original types must be used in mark assertions, since pointer comparisons are used
578 markAssertions( haveAssertions, needAssertions, functionType );
579 markAssertions( haveAssertions, needAssertions, otherFunction );
580
581 result = true;
582 } // if
583 } // if
584 } // if
585 } // if
586 }
587
588 template< typename RefType >
589 void Unify::handleRefType( RefType *inst, Type *other ) {
590 // check that other type is compatible and named the same
591 RefType *otherStruct = dynamic_cast< RefType* >( other );
592 result = otherStruct && inst->get_name() == otherStruct->get_name();
593 }
594
595 template< typename RefType >
596 void Unify::handleGenericRefType( RefType *inst, Type *other ) {
597 // Check that other type is compatible and named the same
598 handleRefType( inst, other );
599 if ( ! result ) return;
600 // Check that parameters of types unify, if any
601 std::list< Expression* > params = inst->get_parameters();
602 std::list< Expression* > otherParams = ((RefType*)other)->get_parameters();
603
604 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
605 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
606 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
607 assertf(param, "Aggregate parameters should be type expressions");
608 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
609 assertf(otherParam, "Aggregate parameters should be type expressions");
610
611 Type* paramTy = param->get_type();
612 Type* otherParamTy = otherParam->get_type();
613
614 bool tupleParam = Tuples::isTtype( paramTy );
615 bool otherTupleParam = Tuples::isTtype( otherParamTy );
616
617 if ( tupleParam && otherTupleParam ) {
618 ++it; ++jt; // skip ttype parameters for break
619 } else if ( tupleParam ) {
620 // bundle other parameters into tuple to match
621 std::list< Type * > binderTypes;
622
623 do {
624 binderTypes.push_back( otherParam->get_type()->clone() );
625 ++jt;
626
627 if ( jt == otherParams.end() ) break;
628
629 otherParam = dynamic_cast< TypeExpr* >(*jt);
630 assertf(otherParam, "Aggregate parameters should be type expressions");
631 } while (true);
632
633 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
634 ++it; // skip ttype parameter for break
635 } else if ( otherTupleParam ) {
636 // bundle parameters into tuple to match other
637 std::list< Type * > binderTypes;
638
639 do {
640 binderTypes.push_back( param->get_type()->clone() );
641 ++it;
642
643 if ( it == params.end() ) break;
644
645 param = dynamic_cast< TypeExpr* >(*it);
646 assertf(param, "Aggregate parameters should be type expressions");
647 } while (true);
648
649 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
650 ++jt; // skip ttype parameter for break
651 }
652
653 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
654 result = false;
655 return;
656 }
657
658 // ttype parameter should be last
659 if ( tupleParam || otherTupleParam ) break;
660 }
661 result = ( it == params.end() && jt == otherParams.end() );
662 }
663
664 void Unify::visit(StructInstType *structInst) {
665 handleGenericRefType( structInst, type2 );
666 }
667
668 void Unify::visit(UnionInstType *unionInst) {
669 handleGenericRefType( unionInst, type2 );
670 }
671
672 void Unify::visit(EnumInstType *enumInst) {
673 handleRefType( enumInst, type2 );
674 }
675
676 void Unify::visit(TraitInstType *contextInst) {
677 handleRefType( contextInst, type2 );
678 }
679
680 void Unify::visit(TypeInstType *typeInst) {
681 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
682 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
683 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
684 result = true;
685/// } else {
686/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
687/// if ( nt ) {
688/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
689/// assert( type );
690/// if ( type->get_base() ) {
691/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
692/// }
693/// }
694 } // if
695 }
696
697 template< typename Iterator1, typename Iterator2 >
698 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
699 auto get_type = [](Type * t) { return t; };
700 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
701 Type * t1 = *list1Begin;
702 Type * t2 = *list2Begin;
703 bool isTtype1 = Tuples::isTtype( t1 );
704 bool isTtype2 = Tuples::isTtype( t2 );
705 // xxx - assumes ttype must be last parameter
706 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
707 if ( isTtype1 && ! isTtype2 ) {
708 // combine all of the things in list2, then unify
709 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
710 } else if ( isTtype2 && ! isTtype1 ) {
711 // combine all of the things in list1, then unify
712 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
713 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
714 return false;
715 } // if
716
717 } // for
718 if ( list1Begin != list1End ) {
719 // try unifying empty tuple type with ttype
720 Type * t1 = *list1Begin;
721 if ( Tuples::isTtype( t1 ) ) {
722 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
723 } else return false;
724 } else if ( list2Begin != list2End ) {
725 // try unifying empty tuple type with ttype
726 Type * t2 = *list2Begin;
727 if ( Tuples::isTtype( t2 ) ) {
728 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
729 } else return false;
730 } else {
731 return true;
732 } // if
733 }
734
735 void Unify::visit(TupleType *tupleType) {
736 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
737 std::unique_ptr<TupleType> flat1( tupleType->clone() );
738 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
739 std::list<Type *> types1, types2;
740
741 TtypeExpander expander( env );
742 flat1->acceptMutator( expander );
743 flat2->acceptMutator( expander );
744
745 flatten( flat1.get(), back_inserter( types1 ) );
746 flatten( flat2.get(), back_inserter( types2 ) );
747
748 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
749 } // if
750 }
751
752 void Unify::visit( __attribute__((unused)) VarArgsType *varArgsType ) {
753 result = dynamic_cast< VarArgsType* >( type2 );
754 }
755
756 void Unify::visit( __attribute__((unused)) ZeroType *zeroType ) {
757 result = dynamic_cast< ZeroType* >( type2 );
758 }
759
760 void Unify::visit( __attribute__((unused)) OneType *oneType ) {
761 result = dynamic_cast< OneType* >( type2 );
762 }
763
764 // xxx - compute once and store in the FunctionType?
765 Type * extractResultType( FunctionType * function ) {
766 if ( function->get_returnVals().size() == 0 ) {
767 return new VoidType( Type::Qualifiers() );
768 } else if ( function->get_returnVals().size() == 1 ) {
769 return function->get_returnVals().front()->get_type()->clone();
770 } else {
771 std::list< Type * > types;
772 for ( DeclarationWithType * decl : function->get_returnVals() ) {
773 types.push_back( decl->get_type()->clone() );
774 } // for
775 return new TupleType( Type::Qualifiers(), types );
776 }
777 }
778} // namespace ResolvExpr
779
780// Local Variables: //
781// tab-width: 4 //
782// mode: c++ //
783// compile-command: "make install" //
784// End: //
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