source: src/ResolvExpr/Unify.cc@ 89be1c68

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 89be1c68 was b1e63ac5, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

Merge branch 'master' into references
  • Property mode set to 100644
File size: 31.8 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// Unify.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sun May 17 12:27:10 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : 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 OpenVarSet::const_iterator tyvar = openVars.find( typeInst->get_name() );
146 assert( tyvar != openVars.end() );
147 if ( ! tyVarCompatible( tyvar->second, other ) ) {
148 return false;
149 } // if
150 if ( occurs( other, typeInst->get_name(), env ) ) {
151 return false;
152 } // if
153 EqvClass curClass;
154 if ( env.lookup( typeInst->get_name(), curClass ) ) {
155 if ( curClass.type ) {
156 Type *common = 0;
157 // attempt to unify equivalence class type (which has qualifiers stripped, so they must be restored) with the type to bind to
158 std::auto_ptr< Type > newType( curClass.type->clone() );
159 newType->get_qualifiers() = typeInst->get_qualifiers();
160 if ( unifyInexact( newType.get(), other, env, needAssertions, haveAssertions, openVars, widenMode & WidenMode( curClass.allowWidening, true ), indexer, common ) ) {
161 if ( common ) {
162 common->get_qualifiers() = Type::Qualifiers();
163 delete curClass.type;
164 curClass.type = common;
165 env.add( curClass );
166 } // if
167 return true;
168 } else {
169 return false;
170 } // if
171 } else {
172 curClass.type = other->clone();
173 curClass.type->get_qualifiers() = Type::Qualifiers();
174 curClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
175 env.add( curClass );
176 } // if
177 } else {
178 EqvClass newClass;
179 newClass.vars.insert( typeInst->get_name() );
180 newClass.type = other->clone();
181 newClass.type->get_qualifiers() = Type::Qualifiers();
182 newClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
183 newClass.data = data;
184 env.add( newClass );
185 } // if
186 return true;
187 }
188
189 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 ) {
190 bool result = true;
191 EqvClass class1, class2;
192 bool hasClass1 = false, hasClass2 = false;
193 bool widen1 = false, widen2 = false;
194 Type *type1 = 0, *type2 = 0;
195
196 if ( env.lookup( var1->get_name(), class1 ) ) {
197 hasClass1 = true;
198 if ( class1.type ) {
199 if ( occurs( class1.type, var2->get_name(), env ) ) {
200 return false;
201 } // if
202 type1 = class1.type->clone();
203 } // if
204 widen1 = widenMode.widenFirst && class1.allowWidening;
205 } // if
206 if ( env.lookup( var2->get_name(), class2 ) ) {
207 hasClass2 = true;
208 if ( class2.type ) {
209 if ( occurs( class2.type, var1->get_name(), env ) ) {
210 return false;
211 } // if
212 type2 = class2.type->clone();
213 } // if
214 widen2 = widenMode.widenSecond && class2.allowWidening;
215 } // if
216
217 if ( type1 && type2 ) {
218// std::cerr << "has type1 && type2" << std::endl;
219 WidenMode newWidenMode ( widen1, widen2 );
220 Type *common = 0;
221 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, newWidenMode, indexer, common ) ) {
222 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
223 class1.allowWidening = widen1 && widen2;
224 if ( common ) {
225 common->get_qualifiers() = Type::Qualifiers();
226 delete class1.type;
227 class1.type = common;
228 } // if
229 env.add( class1 );
230 } else {
231 result = false;
232 } // if
233 } else if ( hasClass1 && hasClass2 ) {
234 if ( type1 ) {
235 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
236 class1.allowWidening = widen1;
237 env.add( class1 );
238 } else {
239 class2.vars.insert( class1.vars.begin(), class1.vars.end() );
240 class2.allowWidening = widen2;
241 env.add( class2 );
242 } // if
243 } else if ( hasClass1 ) {
244 class1.vars.insert( var2->get_name() );
245 class1.allowWidening = widen1;
246 env.add( class1 );
247 } else if ( hasClass2 ) {
248 class2.vars.insert( var1->get_name() );
249 class2.allowWidening = widen2;
250 env.add( class2 );
251 } else {
252 EqvClass newClass;
253 newClass.vars.insert( var1->get_name() );
254 newClass.vars.insert( var2->get_name() );
255 newClass.allowWidening = widen1 && widen2;
256 newClass.data = data;
257 env.add( newClass );
258 } // if
259 delete type1;
260 delete type2;
261 return result;
262 }
263
264 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
265 OpenVarSet closedVars;
266 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
267 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
268 Type *commonType = 0;
269 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
270 if ( commonType ) {
271 delete commonType;
272 } // if
273 return true;
274 } else {
275 return false;
276 } // if
277 }
278
279 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
280 OpenVarSet closedVars;
281 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
282 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
283 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
284 }
285
286 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
287#ifdef DEBUG
288 TypeEnvironment debugEnv( env );
289#endif
290 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
291 return false;
292 }
293
294 bool result;
295 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
296 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
297 OpenVarSet::const_iterator entry1, entry2;
298 if ( var1 ) {
299 entry1 = openVars.find( var1->get_name() );
300 } // if
301 if ( var2 ) {
302 entry2 = openVars.find( var2->get_name() );
303 } // if
304 bool isopen1 = var1 && ( entry1 != openVars.end() );
305 bool isopen2 = var2 && ( entry2 != openVars.end() );
306
307 if ( isopen1 && isopen2 && entry1->second == entry2->second ) {
308 result = bindVarToVar( var1, var2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
309 } else if ( isopen1 ) {
310 result = bindVar( var1, type2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
311 } else if ( isopen2 ) {
312 result = bindVar( var2, type1, entry2->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
313 } else {
314 Unify comparator( type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
315 type1->accept( comparator );
316 result = comparator.get_result();
317 } // if
318#ifdef DEBUG
319 std::cerr << "============ unifyExact" << std::endl;
320 std::cerr << "type1 is ";
321 type1->print( std::cerr );
322 std::cerr << std::endl << "type2 is ";
323 type2->print( std::cerr );
324 std::cerr << std::endl << "openVars are ";
325 printOpenVarSet( openVars, std::cerr, 8 );
326 std::cerr << std::endl << "input env is " << std::endl;
327 debugEnv.print( std::cerr, 8 );
328 std::cerr << std::endl << "result env is " << std::endl;
329 env.print( std::cerr, 8 );
330 std::cerr << "result is " << result << std::endl;
331#endif
332 return result;
333 }
334
335 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
336 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
337 }
338
339 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common ) {
340 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
341 type1->get_qualifiers() = Type::Qualifiers();
342 type2->get_qualifiers() = Type::Qualifiers();
343 bool result;
344#ifdef DEBUG
345 std::cerr << "unifyInexact type 1 is ";
346 type1->print( std::cerr );
347 std::cerr << " type 2 is ";
348 type2->print( std::cerr );
349 std::cerr << std::endl;
350#endif
351 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer ) ) {
352#ifdef DEBUG
353 std::cerr << "unifyInexact: no exact unification found" << std::endl;
354#endif
355 if ( ( common = commonType( type1, type2, widenMode.widenFirst, widenMode.widenSecond, indexer, env, openVars ) ) ) {
356 common->get_qualifiers() = tq1 | tq2;
357#ifdef DEBUG
358 std::cerr << "unifyInexact: common type is ";
359 common->print( std::cerr );
360 std::cerr << std::endl;
361#endif
362 result = true;
363 } else {
364#ifdef DEBUG
365 std::cerr << "unifyInexact: no common type found" << std::endl;
366#endif
367 result = false;
368 } // if
369 } else {
370 if ( tq1 != tq2 ) {
371 if ( ( tq1 > tq2 || widenMode.widenFirst ) && ( tq2 > tq1 || widenMode.widenSecond ) ) {
372 common = type1->clone();
373 common->get_qualifiers() = tq1 | tq2;
374 result = true;
375 } else {
376 result = false;
377 } // if
378 } else {
379 result = true;
380 } // if
381 } // if
382 type1->get_qualifiers() = tq1;
383 type2->get_qualifiers() = tq2;
384 return result;
385 }
386
387 Unify::Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer )
388 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widenMode( widenMode ), indexer( indexer ) {
389 }
390
391 void Unify::visit( __attribute__((unused)) VoidType *voidType) {
392 result = dynamic_cast< VoidType* >( type2 );
393 }
394
395 void Unify::visit(BasicType *basicType) {
396 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
397 result = basicType->get_kind() == otherBasic->get_kind();
398 } // if
399 }
400
401 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
402/// std::cerr << "assertion set is" << std::endl;
403/// printAssertionSet( assertions, std::cerr, 8 );
404/// std::cerr << "looking for ";
405/// assert->print( std::cerr );
406/// std::cerr << std::endl;
407 AssertionSet::iterator i = assertions.find( assert );
408 if ( i != assertions.end() ) {
409/// std::cerr << "found it!" << std::endl;
410 i->second.isUsed = true;
411 } // if
412 }
413
414 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
415 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
416 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
417 markAssertionSet( assertion1, *assert );
418 markAssertionSet( assertion2, *assert );
419 } // for
420 } // for
421 }
422
423 void Unify::visit(PointerType *pointerType) {
424 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
425 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
426 markAssertions( haveAssertions, needAssertions, pointerType );
427 markAssertions( haveAssertions, needAssertions, otherPointer );
428 } // if
429 }
430
431 void Unify::visit(ReferenceType *refType) {
432 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
433 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
434 markAssertions( haveAssertions, needAssertions, refType );
435 markAssertions( haveAssertions, needAssertions, otherRef );
436 } // if
437 }
438
439 void Unify::visit(ArrayType *arrayType) {
440 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
441 // to unify, array types must both be VLA or both not VLA
442 // and must both have a dimension expression or not have a dimension
443 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
444
445 // not positive this is correct in all cases, but it's needed for typedefs
446 if ( arrayType->get_isVarLen() || otherArray->get_isVarLen() ) {
447 return;
448 }
449
450 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
451 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
452 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
453 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
454 // see C11 Reference Manual 6.7.6.2.6
455 // two array types with size specifiers that are integer constant expressions are
456 // compatible if both size specifiers have the same constant value
457 if ( ce1 && ce2 ) {
458 Constant * c1 = ce1->get_constant();
459 Constant * c2 = ce2->get_constant();
460
461 if ( c1->get_value() != c2->get_value() ) {
462 // does not unify if the dimension is different
463 return;
464 }
465 }
466 }
467
468 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
469 } // if
470 }
471
472 template< typename Iterator, typename Func >
473 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
474 std::list< Type * > types;
475 for ( ; begin != end; ++begin ) {
476 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
477 flatten( toType( *begin ), back_inserter( types ) );
478 }
479 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
480 }
481
482 template< typename Iterator1, typename Iterator2 >
483 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
484 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
485 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
486 Type * t1 = (*list1Begin)->get_type();
487 Type * t2 = (*list2Begin)->get_type();
488 bool isTtype1 = Tuples::isTtype( t1 );
489 bool isTtype2 = Tuples::isTtype( t2 );
490 // xxx - assumes ttype must be last parameter
491 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
492 if ( isTtype1 && ! isTtype2 ) {
493 // combine all of the things in list2, then unify
494 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
495 } else if ( isTtype2 && ! isTtype1 ) {
496 // combine all of the things in list1, then unify
497 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
498 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
499 return false;
500 } // if
501 } // for
502 // 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
503 if ( list1Begin != list1End ) {
504 // try unifying empty tuple type with ttype
505 Type * t1 = (*list1Begin)->get_type();
506 if ( Tuples::isTtype( t1 ) ) {
507 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
508 } else return false;
509 } else if ( list2Begin != list2End ) {
510 // try unifying empty tuple type with ttype
511 Type * t2 = (*list2Begin)->get_type();
512 if ( Tuples::isTtype( t2 ) ) {
513 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
514 } else return false;
515 } else {
516 return true;
517 } // if
518 }
519
520 /// Finds ttypes and replaces them with their expansion, if known.
521 /// This needs to be done so that satisfying ttype assertions is easier.
522 /// If this isn't done then argument lists can have wildly different
523 /// size and structure, when they should be compatible.
524 struct TtypeExpander : public Mutator {
525 TypeEnvironment & env;
526 TtypeExpander( TypeEnvironment & env ) : env( env ) {}
527 Type * mutate( TypeInstType * typeInst ) {
528 EqvClass eqvClass;
529 if ( env.lookup( typeInst->get_name(), eqvClass ) ) {
530 if ( eqvClass.data.kind == TypeDecl::Ttype ) {
531 // expand ttype parameter into its actual type
532 if ( eqvClass.type ) {
533 delete typeInst;
534 return eqvClass.type->clone();
535 }
536 }
537 }
538 return typeInst;
539 }
540 };
541
542 /// flattens a list of declarations, so that each tuple type has a single declaration.
543 /// makes use of TtypeExpander to ensure ttypes are flat as well.
544 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
545 dst.clear();
546 for ( DeclarationWithType * dcl : src ) {
547 TtypeExpander expander( env );
548 dcl->acceptMutator( expander );
549 std::list< Type * > types;
550 flatten( dcl->get_type(), back_inserter( types ) );
551 for ( Type * t : types ) {
552 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
553 }
554 delete dcl;
555 }
556 }
557
558 void Unify::visit(FunctionType *functionType) {
559 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
560 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
561 // flatten the parameter lists for both functions so that tuple structure
562 // doesn't affect unification. Must be a clone so that the types don't change.
563 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
564 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
565 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
566 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
567
568 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
569 if ( (flatFunc->get_parameters().size() == flatOther->get_parameters().size() && flatFunc->get_returnVals().size() == flatOther->get_returnVals().size()) || flatFunc->isTtype() || flatOther->isTtype() ) {
570 if ( unifyDeclList( flatFunc->get_parameters().begin(), flatFunc->get_parameters().end(), flatOther->get_parameters().begin(), flatOther->get_parameters().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
571 if ( unifyDeclList( flatFunc->get_returnVals().begin(), flatFunc->get_returnVals().end(), flatOther->get_returnVals().begin(), flatOther->get_returnVals().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
572
573 // the original types must be used in mark assertions, since pointer comparisons are used
574 markAssertions( haveAssertions, needAssertions, functionType );
575 markAssertions( haveAssertions, needAssertions, otherFunction );
576
577 result = true;
578 } // if
579 } // if
580 } // if
581 } // if
582 }
583
584 template< typename RefType >
585 void Unify::handleRefType( RefType *inst, Type *other ) {
586 // check that other type is compatible and named the same
587 RefType *otherStruct = dynamic_cast< RefType* >( other );
588 result = otherStruct && inst->get_name() == otherStruct->get_name();
589 }
590
591 template< typename RefType >
592 void Unify::handleGenericRefType( RefType *inst, Type *other ) {
593 // Check that other type is compatible and named the same
594 handleRefType( inst, other );
595 if ( ! result ) return;
596 // Check that parameters of types unify, if any
597 std::list< Expression* > params = inst->get_parameters();
598 std::list< Expression* > otherParams = ((RefType*)other)->get_parameters();
599
600 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
601 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
602 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
603 assertf(param, "Aggregate parameters should be type expressions");
604 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
605 assertf(otherParam, "Aggregate parameters should be type expressions");
606
607 Type* paramTy = param->get_type();
608 Type* otherParamTy = otherParam->get_type();
609
610 bool tupleParam = Tuples::isTtype( paramTy );
611 bool otherTupleParam = Tuples::isTtype( otherParamTy );
612
613 if ( tupleParam && otherTupleParam ) {
614 ++it; ++jt; // skip ttype parameters for break
615 } else if ( tupleParam ) {
616 // bundle other parameters into tuple to match
617 std::list< Type * > binderTypes;
618
619 do {
620 binderTypes.push_back( otherParam->get_type()->clone() );
621 ++jt;
622
623 if ( jt == otherParams.end() ) break;
624
625 otherParam = dynamic_cast< TypeExpr* >(*jt);
626 assertf(otherParam, "Aggregate parameters should be type expressions");
627 } while (true);
628
629 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
630 ++it; // skip ttype parameter for break
631 } else if ( otherTupleParam ) {
632 // bundle parameters into tuple to match other
633 std::list< Type * > binderTypes;
634
635 do {
636 binderTypes.push_back( param->get_type()->clone() );
637 ++it;
638
639 if ( it == params.end() ) break;
640
641 param = dynamic_cast< TypeExpr* >(*it);
642 assertf(param, "Aggregate parameters should be type expressions");
643 } while (true);
644
645 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
646 ++jt; // skip ttype parameter for break
647 }
648
649 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
650 result = false;
651 return;
652 }
653
654 // ttype parameter should be last
655 if ( tupleParam || otherTupleParam ) break;
656 }
657 result = ( it == params.end() && jt == otherParams.end() );
658 }
659
660 void Unify::visit(StructInstType *structInst) {
661 handleGenericRefType( structInst, type2 );
662 }
663
664 void Unify::visit(UnionInstType *unionInst) {
665 handleGenericRefType( unionInst, type2 );
666 }
667
668 void Unify::visit(EnumInstType *enumInst) {
669 handleRefType( enumInst, type2 );
670 }
671
672 void Unify::visit(TraitInstType *contextInst) {
673 handleRefType( contextInst, type2 );
674 }
675
676 void Unify::visit(TypeInstType *typeInst) {
677 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
678 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
679 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
680 result = true;
681/// } else {
682/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
683/// if ( nt ) {
684/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
685/// assert( type );
686/// if ( type->get_base() ) {
687/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
688/// }
689/// }
690 } // if
691 }
692
693 template< typename Iterator1, typename Iterator2 >
694 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
695 auto get_type = [](Type * t) { return t; };
696 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
697 Type * t1 = *list1Begin;
698 Type * t2 = *list2Begin;
699 bool isTtype1 = Tuples::isTtype( t1 );
700 bool isTtype2 = Tuples::isTtype( t2 );
701 // xxx - assumes ttype must be last parameter
702 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
703 if ( isTtype1 && ! isTtype2 ) {
704 // combine all of the things in list2, then unify
705 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
706 } else if ( isTtype2 && ! isTtype1 ) {
707 // combine all of the things in list1, then unify
708 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
709 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
710 return false;
711 } // if
712
713 } // for
714 if ( list1Begin != list1End ) {
715 // try unifying empty tuple type with ttype
716 Type * t1 = *list1Begin;
717 if ( Tuples::isTtype( t1 ) ) {
718 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
719 } else return false;
720 } else if ( list2Begin != list2End ) {
721 // try unifying empty tuple type with ttype
722 Type * t2 = *list2Begin;
723 if ( Tuples::isTtype( t2 ) ) {
724 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
725 } else return false;
726 } else {
727 return true;
728 } // if
729 }
730
731 void Unify::visit(TupleType *tupleType) {
732 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
733 std::unique_ptr<TupleType> flat1( tupleType->clone() );
734 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
735 std::list<Type *> types1, types2;
736
737 TtypeExpander expander( env );
738 flat1->acceptMutator( expander );
739 flat2->acceptMutator( expander );
740
741 flatten( flat1.get(), back_inserter( types1 ) );
742 flatten( flat2.get(), back_inserter( types2 ) );
743
744 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
745 } // if
746 }
747
748 void Unify::visit( __attribute__((unused)) VarArgsType *varArgsType ) {
749 result = dynamic_cast< VarArgsType* >( type2 );
750 }
751
752 void Unify::visit( __attribute__((unused)) ZeroType *zeroType ) {
753 result = dynamic_cast< ZeroType* >( type2 );
754 }
755
756 void Unify::visit( __attribute__((unused)) OneType *oneType ) {
757 result = dynamic_cast< OneType* >( type2 );
758 }
759
760 // xxx - compute once and store in the FunctionType?
761 Type * extractResultType( FunctionType * function ) {
762 if ( function->get_returnVals().size() == 0 ) {
763 return new VoidType( Type::Qualifiers() );
764 } else if ( function->get_returnVals().size() == 1 ) {
765 return function->get_returnVals().front()->get_type()->clone();
766 } else {
767 std::list< Type * > types;
768 for ( DeclarationWithType * decl : function->get_returnVals() ) {
769 types.push_back( decl->get_type()->clone() );
770 } // for
771 return new TupleType( Type::Qualifiers(), types );
772 }
773 }
774} // namespace ResolvExpr
775
776// Local Variables: //
777// tab-width: 4 //
778// mode: c++ //
779// compile-command: "make install" //
780// End: //
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