source: src/ResolvExpr/Unify.cc@ d1685588

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 d1685588 was e6cee92, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

Fix TupleAssignment code for references
  • Property mode set to 100644
File size: 31.9 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// Unify.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sun May 17 12:27:10 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Thu Mar 16 16:22:54 2017
13// Update Count : 42
14//
15
16#include <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 common = type1->clone();
380 common->get_qualifiers() = tq1 | tq2;
381 result = true;
382 } // if
383 } // if
384 type1->get_qualifiers() = tq1;
385 type2->get_qualifiers() = tq2;
386 return result;
387 }
388
389 Unify::Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer )
390 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widenMode( widenMode ), indexer( indexer ) {
391 }
392
393 void Unify::visit( __attribute__((unused)) VoidType *voidType) {
394 result = dynamic_cast< VoidType* >( type2 );
395 }
396
397 void Unify::visit(BasicType *basicType) {
398 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
399 result = basicType->get_kind() == otherBasic->get_kind();
400 } // if
401 }
402
403 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
404/// std::cerr << "assertion set is" << std::endl;
405/// printAssertionSet( assertions, std::cerr, 8 );
406/// std::cerr << "looking for ";
407/// assert->print( std::cerr );
408/// std::cerr << std::endl;
409 AssertionSet::iterator i = assertions.find( assert );
410 if ( i != assertions.end() ) {
411/// std::cerr << "found it!" << std::endl;
412 i->second.isUsed = true;
413 } // if
414 }
415
416 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
417 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
418 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
419 markAssertionSet( assertion1, *assert );
420 markAssertionSet( assertion2, *assert );
421 } // for
422 } // for
423 }
424
425 void Unify::visit(PointerType *pointerType) {
426 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
427 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
428 markAssertions( haveAssertions, needAssertions, pointerType );
429 markAssertions( haveAssertions, needAssertions, otherPointer );
430 } // if
431 }
432
433 void Unify::visit(ReferenceType *refType) {
434 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
435 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
436 markAssertions( haveAssertions, needAssertions, refType );
437 markAssertions( haveAssertions, needAssertions, otherRef );
438 } // if
439 }
440
441 void Unify::visit(ArrayType *arrayType) {
442 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
443 // to unify, array types must both be VLA or both not VLA
444 // and must both have a dimension expression or not have a dimension
445 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
446
447 // not positive this is correct in all cases, but it's needed for typedefs
448 if ( arrayType->get_isVarLen() || otherArray->get_isVarLen() ) {
449 return;
450 }
451
452 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
453 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
454 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
455 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
456 // see C11 Reference Manual 6.7.6.2.6
457 // two array types with size specifiers that are integer constant expressions are
458 // compatible if both size specifiers have the same constant value
459 if ( ce1 && ce2 ) {
460 Constant * c1 = ce1->get_constant();
461 Constant * c2 = ce2->get_constant();
462
463 if ( c1->get_value() != c2->get_value() ) {
464 // does not unify if the dimension is different
465 return;
466 }
467 }
468 }
469
470 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
471 } // if
472 }
473
474 template< typename Iterator, typename Func >
475 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
476 std::list< Type * > types;
477 for ( ; begin != end; ++begin ) {
478 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
479 flatten( toType( *begin ), back_inserter( types ) );
480 }
481 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
482 }
483
484 template< typename Iterator1, typename Iterator2 >
485 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
486 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
487 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
488 Type * t1 = (*list1Begin)->get_type();
489 Type * t2 = (*list2Begin)->get_type();
490 bool isTtype1 = Tuples::isTtype( t1 );
491 bool isTtype2 = Tuples::isTtype( t2 );
492 // xxx - assumes ttype must be last parameter
493 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
494 if ( isTtype1 && ! isTtype2 ) {
495 // combine all of the things in list2, then unify
496 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
497 } else if ( isTtype2 && ! isTtype1 ) {
498 // combine all of the things in list1, then unify
499 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
500 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
501 return false;
502 } // if
503 } // for
504 // 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
505 if ( list1Begin != list1End ) {
506 // try unifying empty tuple type with ttype
507 Type * t1 = (*list1Begin)->get_type();
508 if ( Tuples::isTtype( t1 ) ) {
509 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
510 } else return false;
511 } else if ( list2Begin != list2End ) {
512 // try unifying empty tuple type with ttype
513 Type * t2 = (*list2Begin)->get_type();
514 if ( Tuples::isTtype( t2 ) ) {
515 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
516 } else return false;
517 } else {
518 return true;
519 } // if
520 }
521
522 /// Finds ttypes and replaces them with their expansion, if known.
523 /// This needs to be done so that satisfying ttype assertions is easier.
524 /// If this isn't done then argument lists can have wildly different
525 /// size and structure, when they should be compatible.
526 struct TtypeExpander : public Mutator {
527 TypeEnvironment & env;
528 TtypeExpander( TypeEnvironment & env ) : env( env ) {}
529 Type * mutate( TypeInstType * typeInst ) {
530 EqvClass eqvClass;
531 if ( env.lookup( typeInst->get_name(), eqvClass ) ) {
532 if ( eqvClass.data.kind == TypeDecl::Ttype ) {
533 // expand ttype parameter into its actual type
534 if ( eqvClass.type ) {
535 delete typeInst;
536 return eqvClass.type->clone();
537 }
538 }
539 }
540 return typeInst;
541 }
542 };
543
544 /// flattens a list of declarations, so that each tuple type has a single declaration.
545 /// makes use of TtypeExpander to ensure ttypes are flat as well.
546 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
547 dst.clear();
548 for ( DeclarationWithType * dcl : src ) {
549 TtypeExpander expander( env );
550 dcl->acceptMutator( expander );
551 std::list< Type * > types;
552 flatten( dcl->get_type(), back_inserter( types ) );
553 for ( Type * t : types ) {
554 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
555 }
556 delete dcl;
557 }
558 }
559
560 void Unify::visit(FunctionType *functionType) {
561 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
562 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
563 // flatten the parameter lists for both functions so that tuple structure
564 // doesn't affect unification. Must be a clone so that the types don't change.
565 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
566 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
567 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
568 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
569
570 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
571 if ( (flatFunc->get_parameters().size() == flatOther->get_parameters().size() && flatFunc->get_returnVals().size() == flatOther->get_returnVals().size()) || flatFunc->isTtype() || flatOther->isTtype() ) {
572 if ( unifyDeclList( flatFunc->get_parameters().begin(), flatFunc->get_parameters().end(), flatOther->get_parameters().begin(), flatOther->get_parameters().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
573 if ( unifyDeclList( flatFunc->get_returnVals().begin(), flatFunc->get_returnVals().end(), flatOther->get_returnVals().begin(), flatOther->get_returnVals().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
574
575 // the original types must be used in mark assertions, since pointer comparisons are used
576 markAssertions( haveAssertions, needAssertions, functionType );
577 markAssertions( haveAssertions, needAssertions, otherFunction );
578
579 result = true;
580 } // if
581 } // if
582 } // if
583 } // if
584 }
585
586 template< typename RefType >
587 void Unify::handleRefType( RefType *inst, Type *other ) {
588 // check that other type is compatible and named the same
589 RefType *otherStruct = dynamic_cast< RefType* >( other );
590 result = otherStruct && inst->get_name() == otherStruct->get_name();
591 }
592
593 template< typename RefType >
594 void Unify::handleGenericRefType( RefType *inst, Type *other ) {
595 // Check that other type is compatible and named the same
596 handleRefType( inst, other );
597 if ( ! result ) return;
598 // Check that parameters of types unify, if any
599 std::list< Expression* > params = inst->get_parameters();
600 std::list< Expression* > otherParams = ((RefType*)other)->get_parameters();
601
602 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
603 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
604 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
605 assertf(param, "Aggregate parameters should be type expressions");
606 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
607 assertf(otherParam, "Aggregate parameters should be type expressions");
608
609 Type* paramTy = param->get_type();
610 Type* otherParamTy = otherParam->get_type();
611
612 bool tupleParam = Tuples::isTtype( paramTy );
613 bool otherTupleParam = Tuples::isTtype( otherParamTy );
614
615 if ( tupleParam && otherTupleParam ) {
616 ++it; ++jt; // skip ttype parameters for break
617 } else if ( tupleParam ) {
618 // bundle other parameters into tuple to match
619 std::list< Type * > binderTypes;
620
621 do {
622 binderTypes.push_back( otherParam->get_type()->clone() );
623 ++jt;
624
625 if ( jt == otherParams.end() ) break;
626
627 otherParam = dynamic_cast< TypeExpr* >(*jt);
628 assertf(otherParam, "Aggregate parameters should be type expressions");
629 } while (true);
630
631 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
632 ++it; // skip ttype parameter for break
633 } else if ( otherTupleParam ) {
634 // bundle parameters into tuple to match other
635 std::list< Type * > binderTypes;
636
637 do {
638 binderTypes.push_back( param->get_type()->clone() );
639 ++it;
640
641 if ( it == params.end() ) break;
642
643 param = dynamic_cast< TypeExpr* >(*it);
644 assertf(param, "Aggregate parameters should be type expressions");
645 } while (true);
646
647 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
648 ++jt; // skip ttype parameter for break
649 }
650
651 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
652 result = false;
653 return;
654 }
655
656 // ttype parameter should be last
657 if ( tupleParam || otherTupleParam ) break;
658 }
659 result = ( it == params.end() && jt == otherParams.end() );
660 }
661
662 void Unify::visit(StructInstType *structInst) {
663 handleGenericRefType( structInst, type2 );
664 }
665
666 void Unify::visit(UnionInstType *unionInst) {
667 handleGenericRefType( unionInst, type2 );
668 }
669
670 void Unify::visit(EnumInstType *enumInst) {
671 handleRefType( enumInst, type2 );
672 }
673
674 void Unify::visit(TraitInstType *contextInst) {
675 handleRefType( contextInst, type2 );
676 }
677
678 void Unify::visit(TypeInstType *typeInst) {
679 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
680 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
681 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
682 result = true;
683/// } else {
684/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
685/// if ( nt ) {
686/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
687/// assert( type );
688/// if ( type->get_base() ) {
689/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
690/// }
691/// }
692 } // if
693 }
694
695 template< typename Iterator1, typename Iterator2 >
696 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
697 auto get_type = [](Type * t) { return t; };
698 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
699 Type * t1 = *list1Begin;
700 Type * t2 = *list2Begin;
701 bool isTtype1 = Tuples::isTtype( t1 );
702 bool isTtype2 = Tuples::isTtype( t2 );
703 // xxx - assumes ttype must be last parameter
704 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
705 if ( isTtype1 && ! isTtype2 ) {
706 // combine all of the things in list2, then unify
707 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
708 } else if ( isTtype2 && ! isTtype1 ) {
709 // combine all of the things in list1, then unify
710 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
711 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
712 return false;
713 } // if
714
715 } // for
716 if ( list1Begin != list1End ) {
717 // try unifying empty tuple type with ttype
718 Type * t1 = *list1Begin;
719 if ( Tuples::isTtype( t1 ) ) {
720 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
721 } else return false;
722 } else if ( list2Begin != list2End ) {
723 // try unifying empty tuple type with ttype
724 Type * t2 = *list2Begin;
725 if ( Tuples::isTtype( t2 ) ) {
726 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
727 } else return false;
728 } else {
729 return true;
730 } // if
731 }
732
733 void Unify::visit(TupleType *tupleType) {
734 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
735 std::unique_ptr<TupleType> flat1( tupleType->clone() );
736 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
737 std::list<Type *> types1, types2;
738
739 TtypeExpander expander( env );
740 flat1->acceptMutator( expander );
741 flat2->acceptMutator( expander );
742
743 flatten( flat1.get(), back_inserter( types1 ) );
744 flatten( flat2.get(), back_inserter( types2 ) );
745
746 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
747 } // if
748 }
749
750 void Unify::visit( __attribute__((unused)) VarArgsType *varArgsType ) {
751 result = dynamic_cast< VarArgsType* >( type2 );
752 }
753
754 void Unify::visit( __attribute__((unused)) ZeroType *zeroType ) {
755 result = dynamic_cast< ZeroType* >( type2 );
756 }
757
758 void Unify::visit( __attribute__((unused)) OneType *oneType ) {
759 result = dynamic_cast< OneType* >( type2 );
760 }
761
762 // xxx - compute once and store in the FunctionType?
763 Type * extractResultType( FunctionType * function ) {
764 if ( function->get_returnVals().size() == 0 ) {
765 return new VoidType( Type::Qualifiers() );
766 } else if ( function->get_returnVals().size() == 1 ) {
767 return function->get_returnVals().front()->get_type()->clone();
768 } else {
769 std::list< Type * > types;
770 for ( DeclarationWithType * decl : function->get_returnVals() ) {
771 types.push_back( decl->get_type()->clone() );
772 } // for
773 return new TupleType( Type::Qualifiers(), types );
774 }
775 }
776} // namespace ResolvExpr
777
778// Local Variables: //
779// tab-width: 4 //
780// mode: c++ //
781// compile-command: "make install" //
782// End: //
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