source: src/ResolvExpr/Unify.cc@ ad4d035

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 ad4d035 was b2daebd4, checked in by Aaron Moss <a3moss@…>, 9 years ago

ttype parameters to generic types now bind parameter lists into environment
  • Property mode set to 100644
File size: 31.4 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(FunctionType *functionType);
45 virtual void visit(StructInstType *aggregateUseType);
46 virtual void visit(UnionInstType *aggregateUseType);
47 virtual void visit(EnumInstType *aggregateUseType);
48 virtual void visit(TraitInstType *aggregateUseType);
49 virtual void visit(TypeInstType *aggregateUseType);
50 virtual void visit(TupleType *tupleType);
51 virtual void visit(VarArgsType *varArgsType);
52 virtual void visit(ZeroType *zeroType);
53 virtual void visit(OneType *oneType);
54
55 template< typename RefType > void handleRefType( RefType *inst, Type *other );
56 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
57
58 bool result;
59 Type *type2; // inherited
60 TypeEnvironment &env;
61 AssertionSet &needAssertions;
62 AssertionSet &haveAssertions;
63 const OpenVarSet &openVars;
64 WidenMode widenMode;
65 const SymTab::Indexer &indexer;
66 };
67
68 /// Attempts an inexact unification of type1 and type2.
69 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
70 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common );
71 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
72
73 bool typesCompatible( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
74 TypeEnvironment newEnv;
75 OpenVarSet openVars, closedVars; // added closedVars
76 AssertionSet needAssertions, haveAssertions;
77 Type *newFirst = first->clone(), *newSecond = second->clone();
78 env.apply( newFirst );
79 env.apply( newSecond );
80
81 // do we need to do this? Seems like we do, types should be able to be compatible if they
82 // have free variables that can unify
83 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
84 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
85
86 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
87 delete newFirst;
88 delete newSecond;
89 return result;
90 }
91
92 bool typesCompatibleIgnoreQualifiers( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
93 TypeEnvironment newEnv;
94 OpenVarSet openVars;
95 AssertionSet needAssertions, haveAssertions;
96 Type *newFirst = first->clone(), *newSecond = second->clone();
97 env.apply( newFirst );
98 env.apply( newSecond );
99 newFirst->get_qualifiers() = Type::Qualifiers();
100 newSecond->get_qualifiers() = Type::Qualifiers();
101/// std::cerr << "first is ";
102/// first->print( std::cerr );
103/// std::cerr << std::endl << "second is ";
104/// second->print( std::cerr );
105/// std::cerr << std::endl << "newFirst is ";
106/// newFirst->print( std::cerr );
107/// std::cerr << std::endl << "newSecond is ";
108/// newSecond->print( std::cerr );
109/// std::cerr << std::endl;
110 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
111 delete newFirst;
112 delete newSecond;
113 return result;
114 }
115
116 bool isFtype( Type *type, const SymTab::Indexer &indexer ) {
117 if ( dynamic_cast< FunctionType* >( type ) ) {
118 return true;
119 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( type ) ) {
120 return typeInst->get_isFtype();
121 } // if
122 return false;
123 }
124
125 bool tyVarCompatible( const TypeDecl::Data & data, Type *type, const SymTab::Indexer &indexer ) {
126 switch ( data.kind ) {
127 case TypeDecl::Any:
128 case TypeDecl::Dtype:
129 // to bind to an object type variable, the type must not be a function type.
130 // if the type variable is specified to be a complete type then the incoming
131 // type must also be complete
132 // xxx - should this also check that type is not a tuple type and that it's not a ttype?
133 return ! isFtype( type, indexer ) && (! data.isComplete || type->isComplete() );
134 case TypeDecl::Ftype:
135 return isFtype( type, indexer );
136 case TypeDecl::Ttype:
137 // ttype unifies with any tuple type
138 return dynamic_cast< TupleType * >( type ) || Tuples::isTtype( type );
139 } // switch
140 return false;
141 }
142
143 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 ) {
144 OpenVarSet::const_iterator tyvar = openVars.find( typeInst->get_name() );
145 assert( tyvar != openVars.end() );
146 if ( ! tyVarCompatible( tyvar->second, other, indexer ) ) {
147 return false;
148 } // if
149 if ( occurs( other, typeInst->get_name(), env ) ) {
150 return false;
151 } // if
152 EqvClass curClass;
153 if ( env.lookup( typeInst->get_name(), curClass ) ) {
154 if ( curClass.type ) {
155 Type *common = 0;
156 // attempt to unify equivalence class type (which has qualifiers stripped, so they must be restored) with the type to bind to
157 std::auto_ptr< Type > newType( curClass.type->clone() );
158 newType->get_qualifiers() = typeInst->get_qualifiers();
159 if ( unifyInexact( newType.get(), other, env, needAssertions, haveAssertions, openVars, widenMode & WidenMode( curClass.allowWidening, true ), indexer, common ) ) {
160 if ( common ) {
161 common->get_qualifiers() = Type::Qualifiers();
162 delete curClass.type;
163 curClass.type = common;
164 env.add( curClass );
165 } // if
166 return true;
167 } else {
168 return false;
169 } // if
170 } else {
171 curClass.type = other->clone();
172 curClass.type->get_qualifiers() = Type::Qualifiers();
173 curClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
174 env.add( curClass );
175 } // if
176 } else {
177 EqvClass newClass;
178 newClass.vars.insert( typeInst->get_name() );
179 newClass.type = other->clone();
180 newClass.type->get_qualifiers() = Type::Qualifiers();
181 newClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
182 newClass.data = data;
183 env.add( newClass );
184 } // if
185 return true;
186 }
187
188 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 ) {
189 bool result = true;
190 EqvClass class1, class2;
191 bool hasClass1 = false, hasClass2 = false;
192 bool widen1 = false, widen2 = false;
193 Type *type1 = 0, *type2 = 0;
194
195 if ( env.lookup( var1->get_name(), class1 ) ) {
196 hasClass1 = true;
197 if ( class1.type ) {
198 if ( occurs( class1.type, var2->get_name(), env ) ) {
199 return false;
200 } // if
201 type1 = class1.type->clone();
202 } // if
203 widen1 = widenMode.widenFirst && class1.allowWidening;
204 } // if
205 if ( env.lookup( var2->get_name(), class2 ) ) {
206 hasClass2 = true;
207 if ( class2.type ) {
208 if ( occurs( class2.type, var1->get_name(), env ) ) {
209 return false;
210 } // if
211 type2 = class2.type->clone();
212 } // if
213 widen2 = widenMode.widenSecond && class2.allowWidening;
214 } // if
215
216 if ( type1 && type2 ) {
217// std::cerr << "has type1 && type2" << std::endl;
218 WidenMode newWidenMode ( widen1, widen2 );
219 Type *common = 0;
220 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, newWidenMode, indexer, common ) ) {
221 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
222 class1.allowWidening = widen1 && widen2;
223 if ( common ) {
224 common->get_qualifiers() = Type::Qualifiers();
225 delete class1.type;
226 class1.type = common;
227 } // if
228 env.add( class1 );
229 } else {
230 result = false;
231 } // if
232 } else if ( hasClass1 && hasClass2 ) {
233 if ( type1 ) {
234 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
235 class1.allowWidening = widen1;
236 env.add( class1 );
237 } else {
238 class2.vars.insert( class1.vars.begin(), class1.vars.end() );
239 class2.allowWidening = widen2;
240 env.add( class2 );
241 } // if
242 } else if ( hasClass1 ) {
243 class1.vars.insert( var2->get_name() );
244 class1.allowWidening = widen1;
245 env.add( class1 );
246 } else if ( hasClass2 ) {
247 class2.vars.insert( var1->get_name() );
248 class2.allowWidening = widen2;
249 env.add( class2 );
250 } else {
251 EqvClass newClass;
252 newClass.vars.insert( var1->get_name() );
253 newClass.vars.insert( var2->get_name() );
254 newClass.allowWidening = widen1 && widen2;
255 newClass.data = data;
256 env.add( newClass );
257 } // if
258 delete type1;
259 delete type2;
260 return result;
261 }
262
263 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
264 OpenVarSet closedVars;
265 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
266 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
267 Type *commonType = 0;
268 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
269 if ( commonType ) {
270 delete commonType;
271 } // if
272 return true;
273 } else {
274 return false;
275 } // if
276 }
277
278 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
279 OpenVarSet closedVars;
280 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
281 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
282 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
283 }
284
285 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
286#ifdef DEBUG
287 TypeEnvironment debugEnv( env );
288#endif
289 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
290 return false;
291 }
292
293 bool result;
294 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
295 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
296 OpenVarSet::const_iterator entry1, entry2;
297 if ( var1 ) {
298 entry1 = openVars.find( var1->get_name() );
299 } // if
300 if ( var2 ) {
301 entry2 = openVars.find( var2->get_name() );
302 } // if
303 bool isopen1 = var1 && ( entry1 != openVars.end() );
304 bool isopen2 = var2 && ( entry2 != openVars.end() );
305
306 if ( isopen1 && isopen2 && entry1->second == entry2->second ) {
307 result = bindVarToVar( var1, var2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
308 } else if ( isopen1 ) {
309 result = bindVar( var1, type2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
310 } else if ( isopen2 ) {
311 result = bindVar( var2, type1, entry2->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
312 } else {
313 Unify comparator( type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
314 type1->accept( comparator );
315 result = comparator.get_result();
316 } // if
317#ifdef DEBUG
318 std::cerr << "============ unifyExact" << std::endl;
319 std::cerr << "type1 is ";
320 type1->print( std::cerr );
321 std::cerr << std::endl << "type2 is ";
322 type2->print( std::cerr );
323 std::cerr << std::endl << "openVars are ";
324 printOpenVarSet( openVars, std::cerr, 8 );
325 std::cerr << std::endl << "input env is " << std::endl;
326 debugEnv.print( std::cerr, 8 );
327 std::cerr << std::endl << "result env is " << std::endl;
328 env.print( std::cerr, 8 );
329 std::cerr << "result is " << result << std::endl;
330#endif
331 return result;
332 }
333
334 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
335 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
336 }
337
338 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common ) {
339 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
340 type1->get_qualifiers() = Type::Qualifiers();
341 type2->get_qualifiers() = Type::Qualifiers();
342 bool result;
343#ifdef DEBUG
344 std::cerr << "unifyInexact type 1 is ";
345 type1->print( std::cerr );
346 std::cerr << "type 2 is ";
347 type2->print( std::cerr );
348 std::cerr << std::endl;
349#endif
350 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer ) ) {
351#ifdef DEBUG
352 std::cerr << "unifyInexact: no exact unification found" << std::endl;
353#endif
354 if ( ( common = commonType( type1, type2, widenMode.widenFirst, widenMode.widenSecond, indexer, env, openVars ) ) ) {
355 common->get_qualifiers() = tq1 | tq2;
356#ifdef DEBUG
357 std::cerr << "unifyInexact: common type is ";
358 common->print( std::cerr );
359 std::cerr << std::endl;
360#endif
361 result = true;
362 } else {
363#ifdef DEBUG
364 std::cerr << "unifyInexact: no common type found" << std::endl;
365#endif
366 result = false;
367 } // if
368 } else {
369 if ( tq1 != tq2 ) {
370 if ( ( tq1 > tq2 || widenMode.widenFirst ) && ( tq2 > tq1 || widenMode.widenSecond ) ) {
371 common = type1->clone();
372 common->get_qualifiers() = tq1 | tq2;
373 result = true;
374 } else {
375 result = false;
376 } // if
377 } else {
378 result = true;
379 } // if
380 } // if
381 type1->get_qualifiers() = tq1;
382 type2->get_qualifiers() = tq2;
383 return result;
384 }
385
386 Unify::Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer )
387 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widenMode( widenMode ), indexer( indexer ) {
388 }
389
390 void Unify::visit(VoidType *voidType) {
391 result = dynamic_cast< VoidType* >( type2 );
392 }
393
394 void Unify::visit(BasicType *basicType) {
395 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
396 result = basicType->get_kind() == otherBasic->get_kind();
397 } // if
398 }
399
400 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
401/// std::cerr << "assertion set is" << std::endl;
402/// printAssertionSet( assertions, std::cerr, 8 );
403/// std::cerr << "looking for ";
404/// assert->print( std::cerr );
405/// std::cerr << std::endl;
406 AssertionSet::iterator i = assertions.find( assert );
407 if ( i != assertions.end() ) {
408/// std::cerr << "found it!" << std::endl;
409 i->second.isUsed = true;
410 } // if
411 }
412
413 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
414 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
415 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
416 markAssertionSet( assertion1, *assert );
417 markAssertionSet( assertion2, *assert );
418 } // for
419 } // for
420 }
421
422 void Unify::visit(PointerType *pointerType) {
423 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
424 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
425 markAssertions( haveAssertions, needAssertions, pointerType );
426 markAssertions( haveAssertions, needAssertions, otherPointer );
427 } // if
428 }
429
430 void Unify::visit(ArrayType *arrayType) {
431 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
432 // to unify, array types must both be VLA or both not VLA
433 // and must both have a dimension expression or not have a dimension
434 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
435
436 // not positive this is correct in all cases, but it's needed for typedefs
437 if ( arrayType->get_isVarLen() || otherArray->get_isVarLen() ) {
438 return;
439 }
440
441 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
442 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
443 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
444 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
445 // see C11 Reference Manual 6.7.6.2.6
446 // two array types with size specifiers that are integer constant expressions are
447 // compatible if both size specifiers have the same constant value
448 if ( ce1 && ce2 ) {
449 Constant * c1 = ce1->get_constant();
450 Constant * c2 = ce2->get_constant();
451
452 if ( c1->get_value() != c2->get_value() ) {
453 // does not unify if the dimension is different
454 return;
455 }
456 }
457 }
458
459 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
460 } // if
461 }
462
463 template< typename Iterator, typename Func >
464 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
465 std::list< Type * > types;
466 for ( ; begin != end; ++begin ) {
467 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
468 flatten( toType( *begin ), back_inserter( types ) );
469 }
470 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
471 }
472
473 template< typename Iterator1, typename Iterator2 >
474 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
475 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
476 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
477 Type * t1 = (*list1Begin)->get_type();
478 Type * t2 = (*list2Begin)->get_type();
479 bool isTtype1 = Tuples::isTtype( t1 );
480 bool isTtype2 = Tuples::isTtype( t2 );
481 // xxx - assumes ttype must be last parameter
482 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
483 if ( isTtype1 && ! isTtype2 ) {
484 // combine all of the things in list2, then unify
485 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
486 } else if ( isTtype2 && ! isTtype1 ) {
487 // combine all of the things in list1, then unify
488 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
489 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
490 return false;
491 } // if
492 } // for
493 // 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
494 if ( list1Begin != list1End ) {
495 // try unifying empty tuple type with ttype
496 Type * t1 = (*list1Begin)->get_type();
497 if ( Tuples::isTtype( t1 ) ) {
498 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
499 } else return false;
500 } else if ( list2Begin != list2End ) {
501 // try unifying empty tuple type with ttype
502 Type * t2 = (*list2Begin)->get_type();
503 if ( Tuples::isTtype( t2 ) ) {
504 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
505 } else return false;
506 } else {
507 return true;
508 } // if
509 }
510
511 /// Finds ttypes and replaces them with their expansion, if known.
512 /// This needs to be done so that satisfying ttype assertions is easier.
513 /// If this isn't done then argument lists can have wildly different
514 /// size and structure, when they should be compatible.
515 struct TtypeExpander : public Mutator {
516 TypeEnvironment & env;
517 TtypeExpander( TypeEnvironment & env ) : env( env ) {}
518 Type * mutate( TypeInstType * typeInst ) {
519 EqvClass eqvClass;
520 if ( env.lookup( typeInst->get_name(), eqvClass ) ) {
521 if ( eqvClass.data.kind == TypeDecl::Ttype ) {
522 // expand ttype parameter into its actual type
523 if ( eqvClass.type ) {
524 delete typeInst;
525 return eqvClass.type->clone();
526 }
527 }
528 }
529 return typeInst;
530 }
531 };
532
533 /// flattens a list of declarations, so that each tuple type has a single declaration.
534 /// makes use of TtypeExpander to ensure ttypes are flat as well.
535 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
536 dst.clear();
537 for ( DeclarationWithType * dcl : src ) {
538 TtypeExpander expander( env );
539 dcl->acceptMutator( expander );
540 std::list< Type * > types;
541 flatten( dcl->get_type(), back_inserter( types ) );
542 for ( Type * t : types ) {
543 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
544 }
545 delete dcl;
546 }
547 }
548
549 void Unify::visit(FunctionType *functionType) {
550 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
551 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
552 // flatten the parameter lists for both functions so that tuple structure
553 // doesn't affect unification. Must be a clone so that the types don't change.
554 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
555 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
556 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
557 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
558
559 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
560 if ( (flatFunc->get_parameters().size() == flatOther->get_parameters().size() && flatFunc->get_returnVals().size() == flatOther->get_returnVals().size()) || flatFunc->isTtype() || flatOther->isTtype() ) {
561 if ( unifyDeclList( flatFunc->get_parameters().begin(), flatFunc->get_parameters().end(), flatOther->get_parameters().begin(), flatOther->get_parameters().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
562 if ( unifyDeclList( flatFunc->get_returnVals().begin(), flatFunc->get_returnVals().end(), flatOther->get_returnVals().begin(), flatOther->get_returnVals().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
563
564 // the original types must be used in mark assertions, since pointer comparisons are used
565 markAssertions( haveAssertions, needAssertions, functionType );
566 markAssertions( haveAssertions, needAssertions, otherFunction );
567
568 result = true;
569 } // if
570 } // if
571 } // if
572 } // if
573 }
574
575 template< typename RefType >
576 void Unify::handleRefType( RefType *inst, Type *other ) {
577 // check that other type is compatible and named the same
578 RefType *otherStruct = dynamic_cast< RefType* >( other );
579 result = otherStruct && inst->get_name() == otherStruct->get_name();
580 }
581
582 template< typename RefType >
583 void Unify::handleGenericRefType( RefType *inst, Type *other ) {
584 // Check that other type is compatible and named the same
585 handleRefType( inst, other );
586 if ( ! result ) return;
587 // Check that parameters of types unify, if any
588 std::list< Expression* > params = inst->get_parameters();
589 std::list< Expression* > otherParams = ((RefType*)other)->get_parameters();
590
591 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
592 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
593 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
594 assertf(param, "Aggregate parameters should be type expressions");
595 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
596 assertf(otherParam, "Aggregate parameters should be type expressions");
597
598 Type* paramTy = param->get_type();
599 Type* otherParamTy = otherParam->get_type();
600
601 bool tupleParam = Tuples::isTtype( paramTy );
602 bool otherTupleParam = Tuples::isTtype( otherParamTy );
603
604 if ( tupleParam && otherTupleParam ) {
605 ++it; ++jt; // skip ttype parameters for break
606 } else if ( tupleParam ) {
607 // bundle other parameters into tuple to match
608 TupleType* binder = new TupleType{ paramTy->get_qualifiers() };
609
610 do {
611 binder->get_types().push_back( otherParam->get_type()->clone() );
612 ++jt;
613
614 if ( jt == otherParams.end() ) break;
615
616 otherParam = dynamic_cast< TypeExpr* >(*jt);
617 assertf(otherParam, "Aggregate parameters should be type expressions");
618 } while (true);
619
620 otherParamTy = binder;
621 ++it; // skip ttype parameter for break
622 } else if ( otherTupleParam ) {
623 // bundle parameters into tuple to match other
624 TupleType* binder = new TupleType{ otherParamTy->get_qualifiers() };
625
626 do {
627 binder->get_types().push_back( param->get_type()->clone() );
628 ++it;
629
630 if ( it == params.end() ) break;
631
632 param = dynamic_cast< TypeExpr* >(*it);
633 assertf(param, "Aggregate parameters should be type expressions");
634 } while (true);
635
636 paramTy = binder;
637 ++jt; // skip ttype parameter for break
638 }
639
640 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
641 result = false;
642 return;
643 }
644
645 // ttype parameter should be last
646 if ( tupleParam || otherTupleParam ) break;
647 }
648 result = ( it == params.end() && jt == otherParams.end() );
649 }
650
651 void Unify::visit(StructInstType *structInst) {
652 handleGenericRefType( structInst, type2 );
653 }
654
655 void Unify::visit(UnionInstType *unionInst) {
656 handleGenericRefType( unionInst, type2 );
657 }
658
659 void Unify::visit(EnumInstType *enumInst) {
660 handleRefType( enumInst, type2 );
661 }
662
663 void Unify::visit(TraitInstType *contextInst) {
664 handleRefType( contextInst, type2 );
665 }
666
667 void Unify::visit(TypeInstType *typeInst) {
668 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
669 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
670 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
671 result = true;
672/// } else {
673/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
674/// if ( nt ) {
675/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
676/// assert( type );
677/// if ( type->get_base() ) {
678/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
679/// }
680/// }
681 } // if
682 }
683
684 template< typename Iterator1, typename Iterator2 >
685 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
686 auto get_type = [](Type * t) { return t; };
687 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
688 Type * t1 = *list1Begin;
689 Type * t2 = *list2Begin;
690 bool isTtype1 = Tuples::isTtype( t1 );
691 bool isTtype2 = Tuples::isTtype( t2 );
692 // xxx - assumes ttype must be last parameter
693 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
694 if ( isTtype1 && ! isTtype2 ) {
695 // combine all of the things in list2, then unify
696 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
697 } else if ( isTtype2 && ! isTtype1 ) {
698 // combine all of the things in list1, then unify
699 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
700 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
701 return false;
702 } // if
703
704 } // for
705 if ( list1Begin != list1End ) {
706 // try unifying empty tuple type with ttype
707 Type * t1 = *list1Begin;
708 if ( Tuples::isTtype( t1 ) ) {
709 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
710 } else return false;
711 } else if ( list2Begin != list2End ) {
712 // try unifying empty tuple type with ttype
713 Type * t2 = *list2Begin;
714 if ( Tuples::isTtype( t2 ) ) {
715 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
716 } else return false;
717 } else {
718 return true;
719 } // if
720 }
721
722 void Unify::visit(TupleType *tupleType) {
723 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
724 std::unique_ptr<TupleType> flat1( tupleType->clone() );
725 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
726 std::list<Type *> types1, types2;
727
728 TtypeExpander expander( env );
729 flat1->acceptMutator( expander );
730 flat2->acceptMutator( expander );
731
732 flatten( flat1.get(), back_inserter( types1 ) );
733 flatten( flat2.get(), back_inserter( types2 ) );
734
735 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, widenMode, indexer );
736 } // if
737 }
738
739 void Unify::visit(VarArgsType *varArgsType) {
740 result = dynamic_cast< VarArgsType* >( type2 );
741 }
742
743 void Unify::visit(ZeroType *zeroType) {
744 result = dynamic_cast< ZeroType* >( type2 );
745 }
746
747 void Unify::visit(OneType *oneType) {
748 result = dynamic_cast< OneType* >( type2 );
749 }
750
751 // xxx - compute once and store in the FunctionType?
752 Type * extractResultType( FunctionType * function ) {
753 if ( function->get_returnVals().size() == 0 ) {
754 return new VoidType( Type::Qualifiers() );
755 } else if ( function->get_returnVals().size() == 1 ) {
756 return function->get_returnVals().front()->get_type()->clone();
757 } else {
758 TupleType * tupleType = new TupleType( Type::Qualifiers() );
759 for ( DeclarationWithType * decl : function->get_returnVals() ) {
760 tupleType->get_types().push_back( decl->get_type()->clone() );
761 } // for
762 return tupleType;
763 }
764 }
765} // namespace ResolvExpr
766
767// Local Variables: //
768// tab-width: 4 //
769// mode: c++ //
770// compile-command: "make install" //
771// End: //
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