source: src/ResolvExpr/Unify.cc@ 97397a26

new-env
Last change on this file since 97397a26 was 982f95d, checked in by Aaron Moss <a3moss@…>, 8 years ago

Start of new environment implementation; terribly broken
  • Property mode set to 100644
File size: 32.5 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// Unify.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sun May 17 12:27:10 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Thu Mar 16 16:22:54 2017
13// Update Count : 42
14//
15
16#include <cassert> // for assertf, assert
17#include <iterator> // for back_insert_iterator, back_inserter
18#include <map> // for _Rb_tree_const_iterator, _Rb_tree_i...
19#include <set> // for set
20#include <string> // for string, operator==, operator!=, bas...
21#include <utility> // for pair, move
22
23#include "Common/PassVisitor.h" // for PassVisitor
24#include "FindOpenVars.h" // for findOpenVars
25#include "Parser/LinkageSpec.h" // for C
26#include "SynTree/Constant.h" // for Constant
27#include "SynTree/Declaration.h" // for TypeDecl, TypeDecl::Data, Declarati...
28#include "SynTree/Expression.h" // for TypeExpr, Expression, ConstantExpr
29#include "SynTree/Mutator.h" // for Mutator
30#include "SynTree/Type.h" // for Type, TypeInstType, FunctionType
31#include "SynTree/Visitor.h" // for Visitor
32#include "Tuples/Tuples.h" // for isTtype
33#include "TypeEnvironment.h" // for ClassRef, AssertionSet, OpenVarSet
34#include "Unify.h"
35#include "typeops.h" // for flatten, occurs, commonType
36
37namespace SymTab {
38class Indexer;
39} // namespace SymTab
40
41// #define DEBUG
42
43namespace ResolvExpr {
44
45 struct Unify : public WithShortCircuiting {
46 Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
47
48 bool get_result() const { return result; }
49
50 void previsit( BaseSyntaxNode * ) { visit_children = false; }
51
52 void postvisit( VoidType * voidType );
53 void postvisit( BasicType * basicType );
54 void postvisit( PointerType * pointerType );
55 void postvisit( ArrayType * arrayType );
56 void postvisit( ReferenceType * refType );
57 void postvisit( FunctionType * functionType );
58 void postvisit( StructInstType * aggregateUseType );
59 void postvisit( UnionInstType * aggregateUseType );
60 void postvisit( EnumInstType * aggregateUseType );
61 void postvisit( TraitInstType * aggregateUseType );
62 void postvisit( TypeInstType * aggregateUseType );
63 void postvisit( TupleType * tupleType );
64 void postvisit( VarArgsType * varArgsType );
65 void postvisit( ZeroType * zeroType );
66 void postvisit( OneType * oneType );
67
68 private:
69 template< typename RefType > void handleRefType( RefType *inst, Type *other );
70 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
71
72 bool result;
73 Type *type2; // inherited
74 TypeEnvironment &env;
75 AssertionSet &needAssertions;
76 AssertionSet &haveAssertions;
77 const OpenVarSet &openVars;
78 WidenMode widenMode;
79 const SymTab::Indexer &indexer;
80 };
81
82 /// Attempts an inexact unification of type1 and type2.
83 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
84 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common );
85 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
86
87 bool typesCompatible( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
88 TypeEnvironment newEnv;
89 OpenVarSet openVars, closedVars; // added closedVars
90 AssertionSet needAssertions, haveAssertions;
91 Type *newFirst = first->clone(), *newSecond = second->clone();
92 env.apply( newFirst );
93 env.apply( newSecond );
94
95 // do we need to do this? Seems like we do, types should be able to be compatible if they
96 // have free variables that can unify
97 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
98 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
99
100 return unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
101 }
102
103 bool typesCompatibleIgnoreQualifiers( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
104 TypeEnvironment newEnv;
105 OpenVarSet openVars;
106 AssertionSet needAssertions, haveAssertions;
107 Type *newFirst = first->clone(), *newSecond = second->clone();
108 env.apply( newFirst );
109 env.apply( newSecond );
110 newFirst->get_qualifiers() = Type::Qualifiers();
111 newSecond->get_qualifiers() = Type::Qualifiers();
112/// std::cerr << "first is ";
113/// first->print( std::cerr );
114/// std::cerr << std::endl << "second is ";
115/// second->print( std::cerr );
116/// std::cerr << std::endl << "newFirst is ";
117/// newFirst->print( std::cerr );
118/// std::cerr << std::endl << "newSecond is ";
119/// newSecond->print( std::cerr );
120/// std::cerr << std::endl;
121 return unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
122 }
123
124 bool isFtype( Type *type ) {
125 if ( dynamic_cast< FunctionType* >( type ) ) {
126 return true;
127 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( type ) ) {
128 return typeInst->get_isFtype();
129 } // if
130 return false;
131 }
132
133 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 ) {
134 // remove references from other, so that type variables can only bind to value types
135 other = other->stripReferences();
136 OpenVarSet::const_iterator tyvar = openVars.find( typeInst->get_name() );
137 assert( tyvar != openVars.end() );
138 if ( ! tyVarCompatible( tyvar->second, other ) ) {
139 return false;
140 } // if
141 if ( occurs( other, typeInst->get_name(), env ) ) {
142 return false;
143 } // if
144 if ( const EqvClass *curClass = env.lookup( typeInst->get_name() ) ) {
145 if ( curClass->type ) {
146 Type *common = 0;
147 // attempt to unify equivalence class type (which has qualifiers stripped, so they must be restored) with the type to bind to
148 Type* newType = curClass->type->clone();
149 newType->get_qualifiers() = typeInst->get_qualifiers();
150 if ( unifyInexact( newType, other, env, needAssertions, haveAssertions, openVars, widenMode & WidenMode( curClass->allowWidening, true ), indexer, common ) ) {
151 if ( common ) {
152 common->get_qualifiers() = Type::Qualifiers();
153 EqvClass newClass = *curClass;
154 newClass.type = common;
155 env.add( std::move(newClass) );
156 } // if
157 return true;
158 } else {
159 return false;
160 } // if
161 } else {
162 EqvClass newClass = *curClass;
163 newClass.type = other->clone();
164 newClass.type->get_qualifiers() = Type::Qualifiers();
165 newClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
166 env.add( std::move(newClass) );
167 } // if
168 } else {
169 EqvClass newClass;
170 newClass.vars.insert( typeInst->get_name() );
171 newClass.type = other->clone();
172 newClass.type->get_qualifiers() = Type::Qualifiers();
173 newClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
174 newClass.data = data;
175 env.add( newClass );
176 } // if
177 return true;
178 }
179
180 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 ) {
181 bool result = true;
182 const EqvClass *class1 = env.lookup( var1->get_name() );
183 const EqvClass *class2 = env.lookup( var2->get_name() );
184 bool widen1 = false, widen2 = false;
185 Type *type1 = nullptr, *type2 = nullptr;
186
187 if ( class1 ) {
188 if ( class1->type ) {
189 if ( occurs( class1->type, var2->get_name(), env ) ) {
190 return false;
191 } // if
192 type1 = class1->type->clone();
193 } // if
194 widen1 = widenMode.widenFirst && class1->allowWidening;
195 } // if
196 if ( class2 ) {
197 if ( class2->type ) {
198 if ( occurs( class2->type, var1->get_name(), env ) ) {
199 return false;
200 } // if
201 type2 = class2->type->clone();
202 } // if
203 widen2 = widenMode.widenSecond && class2->allowWidening;
204 } // if
205
206 if ( type1 && type2 ) {
207// std::cerr << "has type1 && type2" << std::endl;
208 WidenMode newWidenMode ( widen1, widen2 );
209 Type *common = 0;
210 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, newWidenMode, indexer, common ) ) {
211 EqvClass newClass1 = *class1;
212 newClass1.vars.insert( class2->vars.begin(), class2->vars.end() );
213 newClass1.allowWidening = widen1 && widen2;
214 if ( common ) {
215 common->get_qualifiers() = Type::Qualifiers();
216 newClass1.type = common;
217 } // if
218 env.add( std::move(newClass1) );
219 } else {
220 result = false;
221 } // if
222 } else if ( class1 && class2 ) {
223 if ( type1 ) {
224 EqvClass newClass1 = *class1;
225 newClass1.vars.insert( class2->vars.begin(), class2->vars.end() );
226 newClass1.allowWidening = widen1;
227 env.add( std::move(newClass1) );
228 } else {
229 EqvClass newClass2 = *class2;
230 newClass2.vars.insert( class1->vars.begin(), class1->vars.end() );
231 newClass2.allowWidening = widen2;
232 env.add( std::move(newClass2) );
233 } // if
234 } else if ( class1 ) {
235 EqvClass newClass1 = *class1;
236 newClass1.vars.insert( var2->get_name() );
237 newClass1.allowWidening = widen1;
238 env.add( std::move(newClass1) );
239 } else if ( class2 ) {
240 EqvClass newClass2 = *class2;
241 newClass2.vars.insert( var1->get_name() );
242 newClass2.allowWidening = widen2;
243 env.add( std::move(newClass2) );
244 } else {
245 EqvClass newClass;
246 newClass.vars.insert( var1->get_name() );
247 newClass.vars.insert( var2->get_name() );
248 newClass.allowWidening = widen1 && widen2;
249 newClass.data = data;
250 env.add( newClass );
251 } // if
252 return result;
253 }
254
255 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
256 OpenVarSet closedVars;
257 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
258 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
259 Type *commonType = 0;
260 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
261 }
262
263 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
264 OpenVarSet closedVars;
265 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
266 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
267 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
268 }
269
270 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
271#ifdef DEBUG
272 TypeEnvironment debugEnv( env );
273#endif
274 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
275 return false;
276 }
277
278 bool result;
279 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
280 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
281 OpenVarSet::const_iterator entry1, entry2;
282 if ( var1 ) {
283 entry1 = openVars.find( var1->get_name() );
284 } // if
285 if ( var2 ) {
286 entry2 = openVars.find( var2->get_name() );
287 } // if
288 bool isopen1 = var1 && ( entry1 != openVars.end() );
289 bool isopen2 = var2 && ( entry2 != openVars.end() );
290
291 if ( isopen1 && isopen2 && entry1->second == entry2->second ) {
292 result = bindVarToVar( var1, var2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
293 } else if ( isopen1 ) {
294 result = bindVar( var1, type2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
295 } else if ( isopen2 ) { // TODO: swap widenMode values in call, since type positions are flipped?
296 result = bindVar( var2, type1, entry2->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
297 } else {
298 PassVisitor<Unify> comparator( type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
299 type1->accept( comparator );
300 result = comparator.pass.get_result();
301 } // if
302#ifdef DEBUG
303 std::cerr << "============ unifyExact" << std::endl;
304 std::cerr << "type1 is ";
305 type1->print( std::cerr );
306 std::cerr << std::endl << "type2 is ";
307 type2->print( std::cerr );
308 std::cerr << std::endl << "openVars are ";
309 printOpenVarSet( openVars, std::cerr, 8 );
310 std::cerr << std::endl << "input env is " << std::endl;
311 debugEnv.print( std::cerr, 8 );
312 std::cerr << std::endl << "result env is " << std::endl;
313 env.print( std::cerr, 8 );
314 std::cerr << "result is " << result << std::endl;
315#endif
316 return result;
317 }
318
319 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
320 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
321 }
322
323 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common ) {
324 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
325 type1->get_qualifiers() = Type::Qualifiers();
326 type2->get_qualifiers() = Type::Qualifiers();
327 bool result;
328#ifdef DEBUG
329 std::cerr << "unifyInexact type 1 is ";
330 type1->print( std::cerr );
331 std::cerr << " type 2 is ";
332 type2->print( std::cerr );
333 std::cerr << std::endl;
334#endif
335 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer ) ) {
336#ifdef DEBUG
337 std::cerr << "unifyInexact: no exact unification found" << std::endl;
338#endif
339 if ( ( common = commonType( type1, type2, widenMode.widenFirst, widenMode.widenSecond, indexer, env, openVars ) ) ) {
340 common->get_qualifiers() = tq1 | tq2;
341#ifdef DEBUG
342 std::cerr << "unifyInexact: common type is ";
343 common->print( std::cerr );
344 std::cerr << std::endl;
345#endif
346 result = true;
347 } else {
348#ifdef DEBUG
349 std::cerr << "unifyInexact: no common type found" << std::endl;
350#endif
351 result = false;
352 } // if
353 } else {
354 if ( tq1 != tq2 ) {
355 if ( ( tq1 > tq2 || widenMode.widenFirst ) && ( tq2 > tq1 || widenMode.widenSecond ) ) {
356 common = type1->clone();
357 common->get_qualifiers() = tq1 | tq2;
358 result = true;
359 } else {
360 result = false;
361 } // if
362 } else {
363 common = type1->clone();
364 common->get_qualifiers() = tq1 | tq2;
365 result = true;
366 } // if
367 } // if
368 type1->get_qualifiers() = tq1;
369 type2->get_qualifiers() = tq2;
370 return result;
371 }
372
373 Unify::Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer )
374 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widenMode( widenMode ), indexer( indexer ) {
375 }
376
377 void Unify::postvisit( __attribute__((unused)) VoidType *voidType) {
378 result = dynamic_cast< VoidType* >( type2 );
379 }
380
381 void Unify::postvisit(BasicType *basicType) {
382 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
383 result = basicType->get_kind() == otherBasic->get_kind();
384 } // if
385 }
386
387 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
388/// std::cerr << "assertion set is" << std::endl;
389/// printAssertionSet( assertions, std::cerr, 8 );
390/// std::cerr << "looking for ";
391/// assert->print( std::cerr );
392/// std::cerr << std::endl;
393 AssertionSet::iterator i = assertions.find( assert );
394 if ( i != assertions.end() ) {
395/// std::cerr << "found it!" << std::endl;
396 i->second.isUsed = true;
397 } // if
398 }
399
400 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
401 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
402 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
403 markAssertionSet( assertion1, *assert );
404 markAssertionSet( assertion2, *assert );
405 } // for
406 } // for
407 }
408
409 void Unify::postvisit(PointerType *pointerType) {
410 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
411 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
412 markAssertions( haveAssertions, needAssertions, pointerType );
413 markAssertions( haveAssertions, needAssertions, otherPointer );
414 } // if
415 }
416
417 void Unify::postvisit(ReferenceType *refType) {
418 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
419 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
420 markAssertions( haveAssertions, needAssertions, refType );
421 markAssertions( haveAssertions, needAssertions, otherRef );
422 } // if
423 }
424
425 void Unify::postvisit(ArrayType *arrayType) {
426 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
427 // to unify, array types must both be VLA or both not VLA
428 // and must both have a dimension expression or not have a dimension
429 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
430
431 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
432 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
433 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
434 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
435 // see C11 Reference Manual 6.7.6.2.6
436 // two array types with size specifiers that are integer constant expressions are
437 // compatible if both size specifiers have the same constant value
438 if ( ce1 && ce2 ) {
439 Constant * c1 = ce1->get_constant();
440 Constant * c2 = ce2->get_constant();
441
442 if ( c1->get_value() != c2->get_value() ) {
443 // does not unify if the dimension is different
444 return;
445 }
446 }
447 }
448
449 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
450 } // if
451 }
452
453 template< typename Iterator, typename Func >
454 Type* combineTypes( Iterator begin, Iterator end, Func & toType ) {
455 std::list< Type * > types;
456 for ( ; begin != end; ++begin ) {
457 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
458 flatten( toType( *begin ), back_inserter( types ) );
459 }
460 return new TupleType{ Type::Qualifiers(), types };
461 }
462
463 template< typename Iterator1, typename Iterator2 >
464 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
465 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
466 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
467 Type * t1 = (*list1Begin)->get_type();
468 Type * t2 = (*list2Begin)->get_type();
469 bool isTtype1 = Tuples::isTtype( t1 );
470 bool isTtype2 = Tuples::isTtype( t2 );
471 // xxx - assumes ttype must be last parameter
472 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
473 if ( isTtype1 && ! isTtype2 ) {
474 // combine all of the things in list2, then unify
475 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
476 } else if ( isTtype2 && ! isTtype1 ) {
477 // combine all of the things in list1, then unify
478 return unifyExact( combineTypes( list1Begin, list1End, get_type ), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
479 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
480 return false;
481 } // if
482 } // for
483 // 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
484 if ( list1Begin != list1End ) {
485 // try unifying empty tuple type with ttype
486 Type * t1 = (*list1Begin)->get_type();
487 if ( Tuples::isTtype( t1 ) ) {
488 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
489 } else return false;
490 } else if ( list2Begin != list2End ) {
491 // try unifying empty tuple type with ttype
492 Type * t2 = (*list2Begin)->get_type();
493 if ( Tuples::isTtype( t2 ) ) {
494 return unifyExact( combineTypes( list1Begin, list1End, get_type ), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
495 } else return false;
496 } else {
497 return true;
498 } // if
499 }
500
501 /// Finds ttypes and replaces them with their expansion, if known.
502 /// This needs to be done so that satisfying ttype assertions is easier.
503 /// If this isn't done then argument lists can have wildly different
504 /// size and structure, when they should be compatible.
505 struct TtypeExpander : public WithShortCircuiting {
506 TypeEnvironment & tenv;
507 TtypeExpander( TypeEnvironment & tenv ) : tenv( tenv ) {}
508 void premutate( TypeInstType * ) { visit_children = false; }
509 Type * postmutate( TypeInstType * typeInst ) {
510 if ( ClassRef eqvClass = tenv.lookup( typeInst->get_name() ) ) {
511 // expand ttype parameter into its actual type
512 BoundType cBound = eqvClass.get_bound();
513 if ( cBound.data.kind == TypeDecl::Ttype && cBound.type ) {
514 return cBound.type->clone();
515 }
516 }
517 return typeInst;
518 }
519 };
520
521 /// flattens a list of declarations, so that each tuple type has a single declaration.
522 /// makes use of TtypeExpander to ensure ttypes are flat as well.
523 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
524 dst.clear();
525 for ( DeclarationWithType * dcl : src ) {
526 PassVisitor<TtypeExpander> expander( env );
527 dcl->acceptMutator( expander );
528 std::list< Type * > types;
529 flatten( dcl->get_type(), back_inserter( types ) );
530 for ( Type * t : types ) {
531 // outermost const, volatile, _Atomic qualifiers in parameters should not play a role in the unification of function types, since they do not determine whether a function is callable.
532 // Note: MUST consider at least mutex qualifier, since functions can be overloaded on outermost mutex and a mutex function has different requirements than a non-mutex function.
533 t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic);
534
535 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
536 }
537 }
538 }
539
540 void Unify::postvisit(FunctionType *functionType) {
541 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
542 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
543 // flatten the parameter lists for both functions so that tuple structure
544 // doesn't affect unification. Must be a clone so that the types don't change.
545 FunctionType* flatFunc = functionType->clone();
546 FunctionType* flatOther = otherFunction->clone();
547 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
548 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
549
550 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
551 if ( (flatFunc->parameters.size() == flatOther->parameters.size() && flatFunc->returnVals.size() == flatOther->returnVals.size()) || flatFunc->isTtype() || flatOther->isTtype() ) {
552 if ( unifyDeclList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
553 if ( unifyDeclList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->returnVals.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
554
555 // the original types must be used in mark assertions, since pointer comparisons are used
556 markAssertions( haveAssertions, needAssertions, functionType );
557 markAssertions( haveAssertions, needAssertions, otherFunction );
558
559 result = true;
560 } // if
561 } // if
562 } // if
563 } // if
564 }
565
566 template< typename RefType >
567 void Unify::handleRefType( RefType *inst, Type *other ) {
568 // check that other type is compatible and named the same
569 RefType *otherStruct = dynamic_cast< RefType* >( other );
570 result = otherStruct && inst->name == otherStruct->name;
571 }
572
573 template< typename RefType >
574 void Unify::handleGenericRefType( RefType *inst, Type *other ) {
575 // Check that other type is compatible and named the same
576 handleRefType( inst, other );
577 if ( ! result ) return;
578 // Check that parameters of types unify, if any
579 std::list< Expression* > params = inst->parameters;
580 std::list< Expression* > otherParams = ((RefType*)other)->parameters;
581
582 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
583 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
584 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
585 assertf(param, "Aggregate parameters should be type expressions");
586 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
587 assertf(otherParam, "Aggregate parameters should be type expressions");
588
589 Type* paramTy = param->get_type();
590 Type* otherParamTy = otherParam->get_type();
591
592 bool tupleParam = Tuples::isTtype( paramTy );
593 bool otherTupleParam = Tuples::isTtype( otherParamTy );
594
595 if ( tupleParam && otherTupleParam ) {
596 ++it; ++jt; // skip ttype parameters for break
597 } else if ( tupleParam ) {
598 // bundle other parameters into tuple to match
599 std::list< Type * > binderTypes;
600
601 do {
602 binderTypes.push_back( otherParam->get_type()->clone() );
603 ++jt;
604
605 if ( jt == otherParams.end() ) break;
606
607 otherParam = dynamic_cast< TypeExpr* >(*jt);
608 assertf(otherParam, "Aggregate parameters should be type expressions");
609 } while (true);
610
611 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
612 ++it; // skip ttype parameter for break
613 } else if ( otherTupleParam ) {
614 // bundle parameters into tuple to match other
615 std::list< Type * > binderTypes;
616
617 do {
618 binderTypes.push_back( param->get_type()->clone() );
619 ++it;
620
621 if ( it == params.end() ) break;
622
623 param = dynamic_cast< TypeExpr* >(*it);
624 assertf(param, "Aggregate parameters should be type expressions");
625 } while (true);
626
627 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
628 ++jt; // skip ttype parameter for break
629 }
630
631 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
632 result = false;
633 return;
634 }
635
636 // ttype parameter should be last
637 if ( tupleParam || otherTupleParam ) break;
638 }
639 result = ( it == params.end() && jt == otherParams.end() );
640 }
641
642 void Unify::postvisit(StructInstType *structInst) {
643 handleGenericRefType( structInst, type2 );
644 }
645
646 void Unify::postvisit(UnionInstType *unionInst) {
647 handleGenericRefType( unionInst, type2 );
648 }
649
650 void Unify::postvisit(EnumInstType *enumInst) {
651 handleRefType( enumInst, type2 );
652 }
653
654 void Unify::postvisit(TraitInstType *contextInst) {
655 handleRefType( contextInst, type2 );
656 }
657
658 void Unify::postvisit(TypeInstType *typeInst) {
659 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
660 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
661 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
662 result = true;
663/// } else {
664/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
665/// if ( nt ) {
666/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
667/// assert( type );
668/// if ( type->get_base() ) {
669/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
670/// }
671/// }
672 } // if
673 }
674
675 template< typename Iterator1, typename Iterator2 >
676 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
677 auto get_type = [](Type * t) { return t; };
678 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
679 Type * t1 = *list1Begin;
680 Type * t2 = *list2Begin;
681 bool isTtype1 = Tuples::isTtype( t1 );
682 bool isTtype2 = Tuples::isTtype( t2 );
683 // xxx - assumes ttype must be last parameter
684 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
685 if ( isTtype1 && ! isTtype2 ) {
686 // combine all of the things in list2, then unify
687 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
688 } else if ( isTtype2 && ! isTtype1 ) {
689 // combine all of the things in list1, then unify
690 return unifyExact( combineTypes( list1Begin, list1End, get_type ), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
691 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
692 return false;
693 } // if
694
695 } // for
696 if ( list1Begin != list1End ) {
697 // try unifying empty tuple type with ttype
698 Type * t1 = *list1Begin;
699 if ( Tuples::isTtype( t1 ) ) {
700 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
701 } else return false;
702 } else if ( list2Begin != list2End ) {
703 // try unifying empty tuple type with ttype
704 Type * t2 = *list2Begin;
705 if ( Tuples::isTtype( t2 ) ) {
706 return unifyExact( combineTypes( list1Begin, list1End, get_type ), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
707 } else return false;
708 } else {
709 return true;
710 } // if
711 }
712
713 void Unify::postvisit(TupleType *tupleType) {
714 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
715 TupleType* flat1 = tupleType->clone();
716 TupleType* flat2 = otherTuple->clone();
717 std::list<Type *> types1, types2;
718
719 PassVisitor<TtypeExpander> expander( env );
720 flat1->acceptMutator( expander );
721 flat2->acceptMutator( expander );
722
723 flatten( flat1, back_inserter( types1 ) );
724 flatten( flat2, back_inserter( types2 ) );
725
726 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
727 } // if
728 }
729
730 void Unify::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) {
731 result = dynamic_cast< VarArgsType* >( type2 );
732 }
733
734 void Unify::postvisit( __attribute__((unused)) ZeroType *zeroType ) {
735 result = dynamic_cast< ZeroType* >( type2 );
736 }
737
738 void Unify::postvisit( __attribute__((unused)) OneType *oneType ) {
739 result = dynamic_cast< OneType* >( type2 );
740 }
741
742 // xxx - compute once and store in the FunctionType?
743 Type * extractResultType( FunctionType * function ) {
744 if ( function->get_returnVals().size() == 0 ) {
745 return new VoidType( Type::Qualifiers() );
746 } else if ( function->get_returnVals().size() == 1 ) {
747 return function->get_returnVals().front()->get_type()->clone();
748 } else {
749 std::list< Type * > types;
750 for ( DeclarationWithType * decl : function->get_returnVals() ) {
751 types.push_back( decl->get_type()->clone() );
752 } // for
753 return new TupleType( Type::Qualifiers(), types );
754 }
755 }
756} // namespace ResolvExpr
757
758// Local Variables: //
759// tab-width: 4 //
760// mode: c++ //
761// compile-command: "make install" //
762// End: //
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