source: src/ResolvExpr/Unify.cc@ 1ba3959

Last change on this file since 1ba3959 was 251ce80, checked in by Fangren Yu <f37yu@…>, 2 years ago

remove reference to symbol table in unify
  • Property mode set to 100644
File size: 48.3 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 : Fri Dec 13 23:43:05 2019
13// Update Count : 46
14//
15
16#include "Unify.h"
17
18#include <cassert> // for assertf, assert
19#include <iterator> // for back_insert_iterator, back_inserter
20#include <map> // for _Rb_tree_const_iterator, _Rb_tree_i...
21#include <memory> // for unique_ptr
22#include <set> // for set
23#include <string> // for string, operator==, operator!=, bas...
24#include <utility> // for pair, move
25#include <vector>
26
27#include "AST/Copy.hpp"
28#include "AST/Decl.hpp"
29#include "AST/Node.hpp"
30#include "AST/Pass.hpp"
31#include "AST/Print.hpp"
32#include "AST/Type.hpp"
33#include "AST/TypeEnvironment.hpp"
34#include "Common/PassVisitor.h" // for PassVisitor
35#include "CommonType.hpp" // for commonType
36#include "FindOpenVars.h" // for findOpenVars
37#include "SpecCost.hpp" // for SpecCost
38#include "SynTree/LinkageSpec.h" // for C
39#include "SynTree/Constant.h" // for Constant
40#include "SynTree/Declaration.h" // for TypeDecl, TypeDecl::Data, Declarati...
41#include "SynTree/Expression.h" // for TypeExpr, Expression, ConstantExpr
42#include "SynTree/Mutator.h" // for Mutator
43#include "SynTree/Type.h" // for Type, TypeInstType, FunctionType
44#include "SynTree/Visitor.h" // for Visitor
45#include "Tuples/Tuples.h" // for isTtype
46#include "TypeEnvironment.h" // for EqvClass, AssertionSet, OpenVarSet
47#include "typeops.h" // for flatten, occurs
48
49namespace ast {
50 class SymbolTable;
51}
52
53namespace SymTab {
54 class Indexer;
55} // namespace SymTab
56
57// #define DEBUG
58
59namespace ResolvExpr {
60
61// Template Helpers:
62template< typename Iterator1, typename Iterator2 >
63bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, std::list< Type* > &commonTypes ) {
64 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
65 Type *commonType = 0;
66 if ( ! unify( *list1Begin, *list2Begin, env, needAssertions, haveAssertions, openVars, indexer, commonType ) ) {
67 return false;
68 } // if
69 commonTypes.push_back( commonType );
70 } // for
71 return ( list1Begin == list1End && list2Begin == list2End );
72}
73
74template< typename Iterator1, typename Iterator2 >
75bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
76 std::list< Type* > commonTypes;
77 if ( unifyList( list1Begin, list1End, list2Begin, list2End, env, needAssertions, haveAssertions, openVars, indexer, commonTypes ) ) {
78 deleteAll( commonTypes );
79 return true;
80 } else {
81 return false;
82 } // if
83}
84
85 struct Unify_old : public WithShortCircuiting {
86 Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
87
88 bool get_result() const { return result; }
89
90 void previsit( BaseSyntaxNode * ) { visit_children = false; }
91
92 void postvisit( VoidType * voidType );
93 void postvisit( BasicType * basicType );
94 void postvisit( PointerType * pointerType );
95 void postvisit( ArrayType * arrayType );
96 void postvisit( ReferenceType * refType );
97 void postvisit( FunctionType * functionType );
98 void postvisit( StructInstType * aggregateUseType );
99 void postvisit( UnionInstType * aggregateUseType );
100 void postvisit( EnumInstType * aggregateUseType );
101 void postvisit( TraitInstType * aggregateUseType );
102 void postvisit( TypeInstType * aggregateUseType );
103 void postvisit( TupleType * tupleType );
104 void postvisit( VarArgsType * varArgsType );
105 void postvisit( ZeroType * zeroType );
106 void postvisit( OneType * oneType );
107
108 private:
109 template< typename RefType > void handleRefType( RefType *inst, Type *other );
110 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
111
112 bool result;
113 Type *type2; // inherited
114 TypeEnvironment &env;
115 AssertionSet &needAssertions;
116 AssertionSet &haveAssertions;
117 const OpenVarSet &openVars;
118 WidenMode widen;
119 const SymTab::Indexer &indexer;
120 };
121
122 /// Attempts an inexact unification of type1 and type2.
123 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
124 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common );
125 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
126
127 bool unifyExact(
128 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
129 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
130 WidenMode widen );
131
132 bool typesCompatible( const Type * first, const Type * second, const SymTab::Indexer & indexer, const TypeEnvironment & env ) {
133 TypeEnvironment newEnv;
134 OpenVarSet openVars, closedVars; // added closedVars
135 AssertionSet needAssertions, haveAssertions;
136 Type * newFirst = first->clone(), * newSecond = second->clone();
137 env.apply( newFirst );
138 env.apply( newSecond );
139
140 // do we need to do this? Seems like we do, types should be able to be compatible if they
141 // have free variables that can unify
142 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
143 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
144
145 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
146 delete newFirst;
147 delete newSecond;
148 return result;
149 }
150
151 bool typesCompatible(
152 const ast::Type * first, const ast::Type * second,
153 const ast::TypeEnvironment & env ) {
154 ast::TypeEnvironment newEnv;
155 ast::OpenVarSet open, closed;
156 ast::AssertionSet need, have;
157
158 ast::ptr<ast::Type> newFirst{ first }, newSecond{ second };
159 env.apply( newFirst );
160 env.apply( newSecond );
161
162 findOpenVars( newFirst, open, closed, need, have, FirstClosed );
163 findOpenVars( newSecond, open, closed, need, have, FirstOpen );
164
165 return unifyExact(newFirst, newSecond, newEnv, need, have, open, noWiden() );
166 }
167
168 bool typesCompatibleIgnoreQualifiers( const Type * first, const Type * second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
169 TypeEnvironment newEnv;
170 OpenVarSet openVars;
171 AssertionSet needAssertions, haveAssertions;
172 Type *newFirst = first->clone(), *newSecond = second->clone();
173 env.apply( newFirst );
174 env.apply( newSecond );
175 newFirst->get_qualifiers() = Type::Qualifiers();
176 newSecond->get_qualifiers() = Type::Qualifiers();
177
178 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
179 delete newFirst;
180 delete newSecond;
181 return result;
182 }
183
184 bool typesCompatibleIgnoreQualifiers(
185 const ast::Type * first, const ast::Type * second,
186 const ast::TypeEnvironment & env ) {
187 ast::TypeEnvironment newEnv;
188 ast::OpenVarSet open;
189 ast::AssertionSet need, have;
190
191 ast::Type * newFirst = shallowCopy( first );
192 ast::Type * newSecond = shallowCopy( second );
193 if ( auto temp = dynamic_cast<const ast::EnumInstType *>(first) ) {
194 if ( !dynamic_cast< const ast::EnumInstType * >( second ) ) {
195 const ast::EnumDecl * baseEnum = dynamic_cast<const ast::EnumDecl *>(temp->base.get());
196 if ( auto t = baseEnum->base.get() ) {
197 newFirst = ast::shallowCopy( t );
198 }
199 }
200 } else if ( auto temp = dynamic_cast<const ast::EnumInstType *>(second) ) {
201 const ast::EnumDecl * baseEnum = dynamic_cast<const ast::EnumDecl *>(temp->base.get());
202 if ( auto t = baseEnum->base.get() ) {
203 newSecond = ast::shallowCopy( t );
204 }
205 }
206
207 newFirst ->qualifiers = {};
208 newSecond->qualifiers = {};
209 ast::ptr< ast::Type > t1_(newFirst );
210 ast::ptr< ast::Type > t2_(newSecond);
211
212 ast::ptr< ast::Type > subFirst = env.apply(newFirst).node;
213 ast::ptr< ast::Type > subSecond = env.apply(newSecond).node;
214
215 return unifyExact(
216 subFirst,
217 subSecond,
218 newEnv, need, have, open, noWiden() );
219 }
220
221 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
222 OpenVarSet closedVars;
223 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
224 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
225 Type *commonType = 0;
226 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
227 if ( commonType ) {
228 delete commonType;
229 } // if
230 return true;
231 } else {
232 return false;
233 } // if
234 }
235
236 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
237 OpenVarSet closedVars;
238 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
239 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
240 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
241 }
242
243 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
244#ifdef DEBUG
245 TypeEnvironment debugEnv( env );
246#endif
247 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
248 return false;
249 }
250
251 bool result;
252 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
253 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
254 OpenVarSet::const_iterator entry1, entry2;
255 if ( var1 ) {
256 entry1 = openVars.find( var1->get_name() );
257 } // if
258 if ( var2 ) {
259 entry2 = openVars.find( var2->get_name() );
260 } // if
261 bool isopen1 = var1 && ( entry1 != openVars.end() );
262 bool isopen2 = var2 && ( entry2 != openVars.end() );
263
264 if ( isopen1 && isopen2 ) {
265 if ( entry1->second.kind != entry2->second.kind ) {
266 result = false;
267 } else {
268 result = env.bindVarToVar(
269 var1, var2, TypeDecl::Data{ entry1->second, entry2->second }, needAssertions,
270 haveAssertions, openVars, widen, indexer );
271 }
272 } else if ( isopen1 ) {
273 result = env.bindVar( var1, type2, entry1->second, needAssertions, haveAssertions, openVars, widen, indexer );
274 } else if ( isopen2 ) { // TODO: swap widen values in call, since type positions are flipped?
275 result = env.bindVar( var2, type1, entry2->second, needAssertions, haveAssertions, openVars, widen, indexer );
276 } else {
277 PassVisitor<Unify_old> comparator( type2, env, needAssertions, haveAssertions, openVars, widen, indexer );
278 type1->accept( comparator );
279 result = comparator.pass.get_result();
280 } // if
281#ifdef DEBUG
282 std::cerr << "============ unifyExact" << std::endl;
283 std::cerr << "type1 is ";
284 type1->print( std::cerr );
285 std::cerr << std::endl << "type2 is ";
286 type2->print( std::cerr );
287 std::cerr << std::endl << "openVars are ";
288 printOpenVarSet( openVars, std::cerr, 8 );
289 std::cerr << std::endl << "input env is " << std::endl;
290 debugEnv.print( std::cerr, 8 );
291 std::cerr << std::endl << "result env is " << std::endl;
292 env.print( std::cerr, 8 );
293 std::cerr << "result is " << result << std::endl;
294#endif
295 return result;
296 }
297
298 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
299 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
300 }
301
302 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common ) {
303 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
304 type1->get_qualifiers() = Type::Qualifiers();
305 type2->get_qualifiers() = Type::Qualifiers();
306 bool result;
307#ifdef DEBUG
308 std::cerr << "unifyInexact type 1 is ";
309 type1->print( std::cerr );
310 std::cerr << " type 2 is ";
311 type2->print( std::cerr );
312 std::cerr << std::endl;
313#endif
314 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widen, indexer ) ) {
315#ifdef DEBUG
316 std::cerr << "unifyInexact: no exact unification found" << std::endl;
317#endif
318 if ( ( common = commonType( type1, type2, widen.first, widen.second, indexer, env, openVars ) ) ) {
319 common->tq = tq1.unify( tq2 );
320#ifdef DEBUG
321 std::cerr << "unifyInexact: common type is ";
322 common->print( std::cerr );
323 std::cerr << std::endl;
324#endif
325 result = true;
326 } else {
327#ifdef DEBUG
328 std::cerr << "unifyInexact: no common type found" << std::endl;
329#endif
330 result = false;
331 } // if
332 } else {
333 if ( tq1 != tq2 ) {
334 if ( ( tq1 > tq2 || widen.first ) && ( tq2 > tq1 || widen.second ) ) {
335 common = type1->clone();
336 common->tq = tq1.unify( tq2 );
337 result = true;
338 } else {
339 result = false;
340 } // if
341 } else {
342 common = type1->clone();
343 common->tq = tq1.unify( tq2 );
344 result = true;
345 } // if
346 } // if
347 type1->get_qualifiers() = tq1;
348 type2->get_qualifiers() = tq2;
349 return result;
350 }
351
352 Unify_old::Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer )
353 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widen( widen ), indexer( indexer ) {
354 }
355
356 void Unify_old::postvisit( __attribute__((unused)) VoidType *voidType) {
357 result = dynamic_cast< VoidType* >( type2 );
358 }
359
360 void Unify_old::postvisit(BasicType *basicType) {
361 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
362 result = basicType->get_kind() == otherBasic->get_kind();
363 } // if
364 }
365
366 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
367 AssertionSet::iterator i = assertions.find( assert );
368 if ( i != assertions.end() ) {
369 i->second.isUsed = true;
370 } // if
371 }
372
373 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
374 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
375 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
376 markAssertionSet( assertion1, *assert );
377 markAssertionSet( assertion2, *assert );
378 } // for
379 } // for
380 }
381
382 void Unify_old::postvisit(PointerType *pointerType) {
383 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
384 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
385 markAssertions( haveAssertions, needAssertions, pointerType );
386 markAssertions( haveAssertions, needAssertions, otherPointer );
387 } // if
388 }
389
390 void Unify_old::postvisit(ReferenceType *refType) {
391 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
392 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
393 markAssertions( haveAssertions, needAssertions, refType );
394 markAssertions( haveAssertions, needAssertions, otherRef );
395 } // if
396 }
397
398 void Unify_old::postvisit(ArrayType *arrayType) {
399 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
400 // to unify, array types must both be VLA or both not VLA
401 // and must both have a dimension expression or not have a dimension
402 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
403
404 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
405 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
406 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
407 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
408 // see C11 Reference Manual 6.7.6.2.6
409 // two array types with size specifiers that are integer constant expressions are
410 // compatible if both size specifiers have the same constant value
411 if ( ce1 && ce2 ) {
412 Constant * c1 = ce1->get_constant();
413 Constant * c2 = ce2->get_constant();
414
415 if ( c1->get_value() != c2->get_value() ) {
416 // does not unify if the dimension is different
417 return;
418 }
419 }
420 }
421
422 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
423 } // if
424 }
425
426 template< typename Iterator, typename Func >
427 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
428 std::list< Type * > types;
429 for ( ; begin != end; ++begin ) {
430 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
431 flatten( toType( *begin ), back_inserter( types ) );
432 }
433 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
434 }
435
436 template< typename Iterator1, typename Iterator2 >
437 bool unifyTypeList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
438 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
439 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
440 Type * t1 = (*list1Begin)->get_type();
441 Type * t2 = (*list2Begin)->get_type();
442 bool isTtype1 = Tuples::isTtype( t1 );
443 bool isTtype2 = Tuples::isTtype( t2 );
444 // xxx - assumes ttype must be last parameter
445 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
446 if ( isTtype1 && ! isTtype2 ) {
447 // combine all of the things in list2, then unify
448 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
449 } else if ( isTtype2 && ! isTtype1 ) {
450 // combine all of the things in list1, then unify
451 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
452 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
453 return false;
454 } // if
455 } // for
456 // 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
457 if ( list1Begin != list1End ) {
458 // try unifying empty tuple type with ttype
459 Type * t1 = (*list1Begin)->get_type();
460 if ( Tuples::isTtype( t1 ) ) {
461 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
462 } else return false;
463 } else if ( list2Begin != list2End ) {
464 // try unifying empty tuple type with ttype
465 Type * t2 = (*list2Begin)->get_type();
466 if ( Tuples::isTtype( t2 ) ) {
467 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
468 } else return false;
469 } else {
470 return true;
471 } // if
472 }
473
474 /// Finds ttypes and replaces them with their expansion, if known.
475 /// This needs to be done so that satisfying ttype assertions is easier.
476 /// If this isn't done then argument lists can have wildly different
477 /// size and structure, when they should be compatible.
478 struct TtypeExpander_old : public WithShortCircuiting {
479 TypeEnvironment & tenv;
480 TtypeExpander_old( TypeEnvironment & tenv ) : tenv( tenv ) {}
481 void premutate( TypeInstType * ) { visit_children = false; }
482 Type * postmutate( TypeInstType * typeInst ) {
483 if ( const EqvClass *eqvClass = tenv.lookup( typeInst->get_name() ) ) {
484 // expand ttype parameter into its actual type
485 if ( eqvClass->data.kind == TypeDecl::Ttype && eqvClass->type ) {
486 delete typeInst;
487 return eqvClass->type->clone();
488 }
489 }
490 return typeInst;
491 }
492 };
493
494 /// flattens a list of declarations, so that each tuple type has a single declaration.
495 /// makes use of TtypeExpander to ensure ttypes are flat as well.
496 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
497 dst.clear();
498 for ( DeclarationWithType * dcl : src ) {
499 PassVisitor<TtypeExpander_old> expander( env );
500 dcl->acceptMutator( expander );
501 std::list< Type * > types;
502 flatten( dcl->get_type(), back_inserter( types ) );
503 for ( Type * t : types ) {
504 // 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.
505 // 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.
506 t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic);
507
508 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
509 }
510 delete dcl;
511 }
512 }
513
514 void Unify_old::postvisit(FunctionType *functionType) {
515 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
516 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
517 // flatten the parameter lists for both functions so that tuple structure
518 // doesn't affect unification. Must be a clone so that the types don't change.
519 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
520 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
521 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
522 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
523
524 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
525 if (
526 (flatFunc->parameters.size() == flatOther->parameters.size() &&
527 flatFunc->returnVals.size() == flatOther->returnVals.size())
528 || flatFunc->isTtype()
529 || flatOther->isTtype()
530 ) {
531 if ( unifyTypeList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
532 if ( unifyTypeList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->returnVals.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
533
534 // the original types must be used in mark assertions, since pointer comparisons are used
535 markAssertions( haveAssertions, needAssertions, functionType );
536 markAssertions( haveAssertions, needAssertions, otherFunction );
537
538 result = true;
539 } // if
540 } // if
541 } // if
542 } // if
543 }
544
545 template< typename RefType >
546 void Unify_old::handleRefType( RefType *inst, Type *other ) {
547 // check that other type is compatible and named the same
548 RefType *otherStruct = dynamic_cast< RefType* >( other );
549 result = otherStruct && inst->name == otherStruct->name;
550 }
551
552 template< typename RefType >
553 void Unify_old::handleGenericRefType( RefType *inst, Type *other ) {
554 // Check that other type is compatible and named the same
555 handleRefType( inst, other );
556 if ( ! result ) return;
557 // Check that parameters of types unify, if any
558 std::list< Expression* > params = inst->parameters;
559 std::list< Expression* > otherParams = ((RefType*)other)->parameters;
560
561 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
562 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
563 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
564 assertf(param, "Aggregate parameters should be type expressions");
565 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
566 assertf(otherParam, "Aggregate parameters should be type expressions");
567
568 Type* paramTy = param->get_type();
569 Type* otherParamTy = otherParam->get_type();
570
571 bool tupleParam = Tuples::isTtype( paramTy );
572 bool otherTupleParam = Tuples::isTtype( otherParamTy );
573
574 if ( tupleParam && otherTupleParam ) {
575 ++it; ++jt; // skip ttype parameters for break
576 } else if ( tupleParam ) {
577 // bundle other parameters into tuple to match
578 std::list< Type * > binderTypes;
579
580 do {
581 binderTypes.push_back( otherParam->get_type()->clone() );
582 ++jt;
583
584 if ( jt == otherParams.end() ) break;
585
586 otherParam = dynamic_cast< TypeExpr* >(*jt);
587 assertf(otherParam, "Aggregate parameters should be type expressions");
588 } while (true);
589
590 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
591 ++it; // skip ttype parameter for break
592 } else if ( otherTupleParam ) {
593 // bundle parameters into tuple to match other
594 std::list< Type * > binderTypes;
595
596 do {
597 binderTypes.push_back( param->get_type()->clone() );
598 ++it;
599
600 if ( it == params.end() ) break;
601
602 param = dynamic_cast< TypeExpr* >(*it);
603 assertf(param, "Aggregate parameters should be type expressions");
604 } while (true);
605
606 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
607 ++jt; // skip ttype parameter for break
608 }
609
610 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
611 result = false;
612 return;
613 }
614
615 // ttype parameter should be last
616 if ( tupleParam || otherTupleParam ) break;
617 }
618 result = ( it == params.end() && jt == otherParams.end() );
619 }
620
621 void Unify_old::postvisit(StructInstType *structInst) {
622 handleGenericRefType( structInst, type2 );
623 }
624
625 void Unify_old::postvisit(UnionInstType *unionInst) {
626 handleGenericRefType( unionInst, type2 );
627 }
628
629 void Unify_old::postvisit(EnumInstType *enumInst) {
630 handleRefType( enumInst, type2 );
631 }
632
633 void Unify_old::postvisit(TraitInstType *contextInst) {
634 handleRefType( contextInst, type2 );
635 }
636
637 void Unify_old::postvisit(TypeInstType *typeInst) {
638 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
639 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
640 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
641 result = true;
642/// } else {
643/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
644/// if ( nt ) {
645/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
646/// assert( type );
647/// if ( type->get_base() ) {
648/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
649/// }
650/// }
651 } // if
652 }
653
654 template< typename Iterator1, typename Iterator2 >
655 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
656 auto get_type = [](Type * t) { return t; };
657 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
658 Type * t1 = *list1Begin;
659 Type * t2 = *list2Begin;
660 bool isTtype1 = Tuples::isTtype( t1 );
661 bool isTtype2 = Tuples::isTtype( t2 );
662 // xxx - assumes ttype must be last parameter
663 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
664 if ( isTtype1 && ! isTtype2 ) {
665 // combine all of the things in list2, then unify
666 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
667 } else if ( isTtype2 && ! isTtype1 ) {
668 // combine all of the things in list1, then unify
669 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
670 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
671 return false;
672 } // if
673
674 } // for
675 if ( list1Begin != list1End ) {
676 // try unifying empty tuple type with ttype
677 Type * t1 = *list1Begin;
678 if ( Tuples::isTtype( t1 ) ) {
679 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
680 } else return false;
681 } else if ( list2Begin != list2End ) {
682 // try unifying empty tuple type with ttype
683 Type * t2 = *list2Begin;
684 if ( Tuples::isTtype( t2 ) ) {
685 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
686 } else return false;
687 } else {
688 return true;
689 } // if
690 }
691
692 void Unify_old::postvisit(TupleType *tupleType) {
693 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
694 std::unique_ptr<TupleType> flat1( tupleType->clone() );
695 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
696 std::list<Type *> types1, types2;
697
698 PassVisitor<TtypeExpander_old> expander( env );
699 flat1->acceptMutator( expander );
700 flat2->acceptMutator( expander );
701
702 flatten( flat1.get(), back_inserter( types1 ) );
703 flatten( flat2.get(), back_inserter( types2 ) );
704
705 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
706 } // if
707 }
708
709 void Unify_old::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) {
710 result = dynamic_cast< VarArgsType* >( type2 );
711 }
712
713 void Unify_old::postvisit( __attribute__((unused)) ZeroType *zeroType ) {
714 result = dynamic_cast< ZeroType* >( type2 );
715 }
716
717 void Unify_old::postvisit( __attribute__((unused)) OneType *oneType ) {
718 result = dynamic_cast< OneType* >( type2 );
719 }
720
721 Type * extractResultType( FunctionType * function ) {
722 if ( function->get_returnVals().size() == 0 ) {
723 return new VoidType( Type::Qualifiers() );
724 } else if ( function->get_returnVals().size() == 1 ) {
725 return function->get_returnVals().front()->get_type()->clone();
726 } else {
727 std::list< Type * > types;
728 for ( DeclarationWithType * decl : function->get_returnVals() ) {
729 types.push_back( decl->get_type()->clone() );
730 } // for
731 return new TupleType( Type::Qualifiers(), types );
732 }
733 }
734
735 namespace {
736 /// Replaces ttype variables with their bound types.
737 /// If this isn't done when satifying ttype assertions, then argument lists can have
738 /// different size and structure when they should be compatible.
739 struct TtypeExpander_new : public ast::WithShortCircuiting, public ast::PureVisitor {
740 ast::TypeEnvironment & tenv;
741
742 TtypeExpander_new( ast::TypeEnvironment & env ) : tenv( env ) {}
743
744 const ast::Type * postvisit( const ast::TypeInstType * typeInst ) {
745 if ( const ast::EqvClass * clz = tenv.lookup( *typeInst ) ) {
746 // expand ttype parameter into its actual type
747 if ( clz->data.kind == ast::TypeDecl::Ttype && clz->bound ) {
748 return clz->bound;
749 }
750 }
751 return typeInst;
752 }
753 };
754 }
755
756 std::vector< ast::ptr< ast::Type > > flattenList(
757 const std::vector< ast::ptr< ast::Type > > & src, ast::TypeEnvironment & env
758 ) {
759 std::vector< ast::ptr< ast::Type > > dst;
760 dst.reserve( src.size() );
761 for ( const auto & d : src ) {
762 ast::Pass<TtypeExpander_new> expander{ env };
763 // TtypeExpander pass is impure (may mutate nodes in place)
764 // need to make nodes shared to prevent accidental mutation
765 ast::ptr<ast::Type> dc = d->accept(expander);
766 auto types = flatten( dc );
767 for ( ast::ptr< ast::Type > & t : types ) {
768 // outermost const, volatile, _Atomic qualifiers in parameters should not play
769 // a role in the unification of function types, since they do not determine
770 // whether a function is callable.
771 // NOTE: **must** consider at least mutex qualifier, since functions can be
772 // overloaded on outermost mutex and a mutex function has different
773 // requirements than a non-mutex function
774 remove_qualifiers( t, ast::CV::Const | ast::CV::Volatile | ast::CV::Atomic );
775 dst.emplace_back( t );
776 }
777 }
778 return dst;
779 }
780
781 class Unify_new final : public ast::WithShortCircuiting {
782 const ast::Type * type2;
783 ast::TypeEnvironment & tenv;
784 ast::AssertionSet & need;
785 ast::AssertionSet & have;
786 const ast::OpenVarSet & open;
787 WidenMode widen;
788 public:
789 static size_t traceId;
790 bool result;
791
792 Unify_new(
793 const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need,
794 ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen )
795 : type2(type2), tenv(env), need(need), have(have), open(open), widen(widen),
796 result(false) {}
797
798 void previsit( const ast::Node * ) { visit_children = false; }
799
800 void postvisit( const ast::VoidType * ) {
801 result = dynamic_cast< const ast::VoidType * >( type2 );
802 }
803
804 void postvisit( const ast::BasicType * basic ) {
805 if ( auto basic2 = dynamic_cast< const ast::BasicType * >( type2 ) ) {
806 result = basic->kind == basic2->kind;
807 }
808 }
809
810 void postvisit( const ast::PointerType * pointer ) {
811 if ( auto pointer2 = dynamic_cast< const ast::PointerType * >( type2 ) ) {
812 result = unifyExact(
813 pointer->base, pointer2->base, tenv, need, have, open,
814 noWiden());
815 }
816 }
817
818 void postvisit( const ast::ArrayType * array ) {
819 auto array2 = dynamic_cast< const ast::ArrayType * >( type2 );
820 if ( ! array2 ) return;
821
822 // to unify, array types must both be VLA or both not VLA and both must have a
823 // dimension expression or not have a dimension
824 if ( array->isVarLen != array2->isVarLen ) return;
825 if ( ! array->isVarLen && ! array2->isVarLen
826 && array->dimension && array2->dimension ) {
827 auto ce1 = array->dimension.as< ast::ConstantExpr >();
828 auto ce2 = array2->dimension.as< ast::ConstantExpr >();
829
830 // see C11 Reference Manual 6.7.6.2.6
831 // two array types with size specifiers that are integer constant expressions are
832 // compatible if both size specifiers have the same constant value
833 if ( ce1 && ce2 && ce1->intValue() != ce2->intValue() ) return;
834 }
835
836 result = unifyExact(
837 array->base, array2->base, tenv, need, have, open, noWiden());
838 }
839
840 void postvisit( const ast::ReferenceType * ref ) {
841 if ( auto ref2 = dynamic_cast< const ast::ReferenceType * >( type2 ) ) {
842 result = unifyExact(
843 ref->base, ref2->base, tenv, need, have, open, noWiden());
844 }
845 }
846
847 private:
848
849 template< typename Iter >
850 static bool unifyTypeList(
851 Iter crnt1, Iter end1, Iter crnt2, Iter end2, ast::TypeEnvironment & env,
852 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open
853 ) {
854 while ( crnt1 != end1 && crnt2 != end2 ) {
855 const ast::Type * t1 = *crnt1;
856 const ast::Type * t2 = *crnt2;
857 bool isTuple1 = Tuples::isTtype( t1 );
858 bool isTuple2 = Tuples::isTtype( t2 );
859
860 // assumes here that ttype *must* be last parameter
861 if ( isTuple1 && ! isTuple2 ) {
862 // combine remainder of list2, then unify
863 return unifyExact(
864 t1, tupleFromTypes( crnt2, end2 ), env, need, have, open,
865 noWiden() );
866 } else if ( ! isTuple1 && isTuple2 ) {
867 // combine remainder of list1, then unify
868 return unifyExact(
869 tupleFromTypes( crnt1, end1 ), t2, env, need, have, open,
870 noWiden() );
871 }
872
873 if ( ! unifyExact(
874 t1, t2, env, need, have, open, noWiden() )
875 ) return false;
876
877 ++crnt1; ++crnt2;
878 }
879
880 // May get to the end of one argument list before the other. This is only okay if the
881 // other is a ttype
882 if ( crnt1 != end1 ) {
883 // try unifying empty tuple with ttype
884 const ast::Type * t1 = *crnt1;
885 if ( ! Tuples::isTtype( t1 ) ) return false;
886 return unifyExact(
887 t1, tupleFromTypes( crnt2, end2 ), env, need, have, open,
888 noWiden() );
889 } else if ( crnt2 != end2 ) {
890 // try unifying empty tuple with ttype
891 const ast::Type * t2 = *crnt2;
892 if ( ! Tuples::isTtype( t2 ) ) return false;
893 return unifyExact(
894 tupleFromTypes( crnt1, end1 ), t2, env, need, have, open,
895 noWiden() );
896 }
897
898 return true;
899 }
900
901 static bool unifyTypeList(
902 const std::vector< ast::ptr< ast::Type > > & list1,
903 const std::vector< ast::ptr< ast::Type > > & list2,
904 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
905 const ast::OpenVarSet & open
906 ) {
907 return unifyTypeList(
908 list1.begin(), list1.end(), list2.begin(), list2.end(), env, need, have, open);
909 }
910
911 static void markAssertionSet( ast::AssertionSet & assns, const ast::VariableExpr * assn ) {
912 auto i = assns.find( assn );
913 if ( i != assns.end() ) {
914 i->second.isUsed = true;
915 }
916 }
917
918 /// mark all assertions in `type` used in both `assn1` and `assn2`
919 static void markAssertions(
920 ast::AssertionSet & assn1, ast::AssertionSet & assn2,
921 const ast::FunctionType * type
922 ) {
923 for ( auto & assert : type->assertions ) {
924 markAssertionSet( assn1, assert );
925 markAssertionSet( assn2, assert );
926 }
927 }
928
929 public:
930 void postvisit( const ast::FunctionType * func ) {
931 auto func2 = dynamic_cast< const ast::FunctionType * >( type2 );
932 if ( ! func2 ) return;
933
934 if ( func->isVarArgs != func2->isVarArgs ) return;
935
936 // Flatten the parameter lists for both functions so that tuple structure does not
937 // affect unification. Does not actually mutate function parameters.
938 auto params = flattenList( func->params, tenv );
939 auto params2 = flattenList( func2->params, tenv );
940
941 // sizes don't have to match if ttypes are involved; need to be more precise w.r.t.
942 // where the ttype is to prevent errors
943 if (
944 ( params.size() != params2.size() || func->returns.size() != func2->returns.size() )
945 && ! func->isTtype()
946 && ! func2->isTtype()
947 ) return;
948
949 if ( ! unifyTypeList( params, params2, tenv, need, have, open ) ) return;
950 if ( ! unifyTypeList(
951 func->returns, func2->returns, tenv, need, have, open ) ) return;
952
953 markAssertions( have, need, func );
954 markAssertions( have, need, func2 );
955
956 result = true;
957 }
958
959 private:
960 // Returns: other, cast as XInstType
961 // Assigns this->result: whether types are compatible (up to generic parameters)
962 template< typename XInstType >
963 const XInstType * handleRefType( const XInstType * inst, const ast::Type * other ) {
964 // check that the other type is compatible and named the same
965 auto otherInst = dynamic_cast< const XInstType * >( other );
966 if (otherInst && inst->name == otherInst->name) this->result = otherInst;
967 return otherInst;
968 }
969
970 /// Creates a tuple type based on a list of TypeExpr
971 template< typename Iter >
972 static const ast::Type * tupleFromExprs(
973 const ast::TypeExpr * param, Iter & crnt, Iter end, ast::CV::Qualifiers qs
974 ) {
975 std::vector< ast::ptr< ast::Type > > types;
976 do {
977 types.emplace_back( param->type );
978
979 ++crnt;
980 if ( crnt == end ) break;
981 param = strict_dynamic_cast< const ast::TypeExpr * >( crnt->get() );
982 } while(true);
983
984 return new ast::TupleType{ std::move(types), qs };
985 }
986
987 template< typename XInstType >
988 void handleGenericRefType( const XInstType * inst, const ast::Type * other ) {
989 // check that other type is compatible and named the same
990 const XInstType * otherInst = handleRefType( inst, other );
991 if ( ! this->result ) return;
992
993 // check that parameters of types unify, if any
994 const std::vector< ast::ptr< ast::Expr > > & params = inst->params;
995 const std::vector< ast::ptr< ast::Expr > > & params2 = otherInst->params;
996
997 auto it = params.begin();
998 auto jt = params2.begin();
999 for ( ; it != params.end() && jt != params2.end(); ++it, ++jt ) {
1000 auto param = strict_dynamic_cast< const ast::TypeExpr * >( it->get() );
1001 auto param2 = strict_dynamic_cast< const ast::TypeExpr * >( jt->get() );
1002
1003 ast::ptr< ast::Type > pty = param->type;
1004 ast::ptr< ast::Type > pty2 = param2->type;
1005
1006 bool isTuple = Tuples::isTtype( pty );
1007 bool isTuple2 = Tuples::isTtype( pty2 );
1008
1009 if ( isTuple && isTuple2 ) {
1010 ++it; ++jt; // skip ttype parameters before break
1011 } else if ( isTuple ) {
1012 // bundle remaining params into tuple
1013 pty2 = tupleFromExprs( param2, jt, params2.end(), pty->qualifiers );
1014 ++it; // skip ttype parameter for break
1015 } else if ( isTuple2 ) {
1016 // bundle remaining params into tuple
1017 pty = tupleFromExprs( param, it, params.end(), pty2->qualifiers );
1018 ++jt; // skip ttype parameter for break
1019 }
1020
1021 if ( ! unifyExact(
1022 pty, pty2, tenv, need, have, open, noWiden() ) ) {
1023 result = false;
1024 return;
1025 }
1026
1027 // ttype parameter should be last
1028 if ( isTuple || isTuple2 ) break;
1029 }
1030 result = it == params.end() && jt == params2.end();
1031 }
1032
1033 public:
1034 void postvisit( const ast::StructInstType * aggrType ) {
1035 handleGenericRefType( aggrType, type2 );
1036 }
1037
1038 void postvisit( const ast::UnionInstType * aggrType ) {
1039 handleGenericRefType( aggrType, type2 );
1040 }
1041
1042 void postvisit( const ast::EnumInstType * aggrType ) {
1043 handleRefType( aggrType, type2 );
1044 }
1045
1046 void postvisit( const ast::TraitInstType * aggrType ) {
1047 handleRefType( aggrType, type2 );
1048 }
1049
1050 void postvisit( const ast::TypeInstType * typeInst ) {
1051 assert( open.find( *typeInst ) == open.end() );
1052 handleRefType( typeInst, type2 );
1053 }
1054
1055 private:
1056 /// Creates a tuple type based on a list of Type
1057
1058 static bool unifyList(
1059 const std::vector< ast::ptr< ast::Type > > & list1,
1060 const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env,
1061 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open
1062 ) {
1063 auto crnt1 = list1.begin();
1064 auto crnt2 = list2.begin();
1065 while ( crnt1 != list1.end() && crnt2 != list2.end() ) {
1066 const ast::Type * t1 = *crnt1;
1067 const ast::Type * t2 = *crnt2;
1068 bool isTuple1 = Tuples::isTtype( t1 );
1069 bool isTuple2 = Tuples::isTtype( t2 );
1070
1071 // assumes ttype must be last parameter
1072 if ( isTuple1 && ! isTuple2 ) {
1073 // combine entirety of list2, then unify
1074 return unifyExact(
1075 t1, tupleFromTypes( list2 ), env, need, have, open,
1076 noWiden() );
1077 } else if ( ! isTuple1 && isTuple2 ) {
1078 // combine entirety of list1, then unify
1079 return unifyExact(
1080 tupleFromTypes( list1 ), t2, env, need, have, open,
1081 noWiden() );
1082 }
1083
1084 if ( ! unifyExact(
1085 t1, t2, env, need, have, open, noWiden() )
1086 ) return false;
1087
1088 ++crnt1; ++crnt2;
1089 }
1090
1091 if ( crnt1 != list1.end() ) {
1092 // try unifying empty tuple type with ttype
1093 const ast::Type * t1 = *crnt1;
1094 if ( ! Tuples::isTtype( t1 ) ) return false;
1095 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1096 // from Rob's code
1097 return unifyExact(
1098 t1, tupleFromTypes( list2 ), env, need, have, open,
1099 noWiden() );
1100 } else if ( crnt2 != list2.end() ) {
1101 // try unifying empty tuple with ttype
1102 const ast::Type * t2 = *crnt2;
1103 if ( ! Tuples::isTtype( t2 ) ) return false;
1104 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1105 // from Rob's code
1106 return unifyExact(
1107 tupleFromTypes( list1 ), t2, env, need, have, open,
1108 noWiden() );
1109 }
1110
1111 return true;
1112 }
1113
1114 public:
1115 void postvisit( const ast::TupleType * tuple ) {
1116 auto tuple2 = dynamic_cast< const ast::TupleType * >( type2 );
1117 if ( ! tuple2 ) return;
1118
1119 ast::Pass<TtypeExpander_new> expander{ tenv };
1120
1121 const ast::Type * flat = tuple->accept( expander );
1122 const ast::Type * flat2 = tuple2->accept( expander );
1123
1124 auto types = flatten( flat );
1125 auto types2 = flatten( flat2 );
1126
1127 result = unifyList( types, types2, tenv, need, have, open );
1128 }
1129
1130 void postvisit( const ast::VarArgsType * ) {
1131 result = dynamic_cast< const ast::VarArgsType * >( type2 );
1132 }
1133
1134 void postvisit( const ast::ZeroType * ) {
1135 result = dynamic_cast< const ast::ZeroType * >( type2 );
1136 }
1137
1138 void postvisit( const ast::OneType * ) {
1139 result = dynamic_cast< const ast::OneType * >( type2 );
1140 }
1141
1142 private:
1143 template< typename RefType > void handleRefType( RefType *inst, Type *other );
1144 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
1145 };
1146
1147 // size_t Unify_new::traceId = Stats::Heap::new_stacktrace_id("Unify_new");
1148 bool unify(
1149 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1150 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1151 ast::OpenVarSet & open
1152 ) {
1153 ast::ptr<ast::Type> common;
1154 return unify( type1, type2, env, need, have, open, common );
1155 }
1156
1157 bool unify(
1158 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1159 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1160 ast::OpenVarSet & open, ast::ptr<ast::Type> & common
1161 ) {
1162 ast::OpenVarSet closed;
1163 findOpenVars( type1, open, closed, need, have, FirstClosed );
1164 findOpenVars( type2, open, closed, need, have, FirstOpen );
1165 return unifyInexact(
1166 type1, type2, env, need, have, open, WidenMode{ true, true }, common );
1167 }
1168
1169 bool unifyExact(
1170 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
1171 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1172 WidenMode widen
1173 ) {
1174 if ( type1->qualifiers != type2->qualifiers ) return false;
1175
1176 auto var1 = dynamic_cast< const ast::TypeInstType * >( type1 );
1177 auto var2 = dynamic_cast< const ast::TypeInstType * >( type2 );
1178 ast::OpenVarSet::const_iterator
1179 entry1 = var1 ? open.find( *var1 ) : open.end(),
1180 entry2 = var2 ? open.find( *var2 ) : open.end();
1181 bool isopen1 = entry1 != open.end();
1182 bool isopen2 = entry2 != open.end();
1183
1184 if ( isopen1 && isopen2 ) {
1185 if ( entry1->second.kind != entry2->second.kind ) return false;
1186 return env.bindVarToVar(
1187 var1, var2, ast::TypeData{ entry1->second, entry2->second }, need, have,
1188 open, widen );
1189 } else if ( isopen1 ) {
1190 return env.bindVar( var1, type2, entry1->second, need, have, open, widen );
1191 } else if ( isopen2 ) {
1192 return env.bindVar( var2, type1, entry2->second, need, have, open, widen );
1193 } else {
1194 return ast::Pass<Unify_new>::read(
1195 type1, type2, env, need, have, open, widen );
1196 }
1197 }
1198
1199 bool unifyInexact(
1200 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1201 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1202 const ast::OpenVarSet & open, WidenMode widen,
1203 ast::ptr<ast::Type> & common
1204 ) {
1205 ast::CV::Qualifiers q1 = type1->qualifiers, q2 = type2->qualifiers;
1206
1207 // force t1 and t2 to be cloned if their qualifiers must be stripped, so that type1 and
1208 // type2 are left unchanged; calling convention forces type{1,2}->strong_ref >= 1
1209 ast::Type * t1 = shallowCopy(type1.get());
1210 ast::Type * t2 = shallowCopy(type2.get());
1211 t1->qualifiers = {};
1212 t2->qualifiers = {};
1213 ast::ptr< ast::Type > t1_(t1);
1214 ast::ptr< ast::Type > t2_(t2);
1215
1216 if ( unifyExact( t1, t2, env, need, have, open, widen ) ) {
1217 // if exact unification on unqualified types, try to merge qualifiers
1218 if ( q1 == q2 || ( ( q1 > q2 || widen.first ) && ( q2 > q1 || widen.second ) ) ) {
1219 t1->qualifiers = q1 | q2;
1220 common = t1;
1221 return true;
1222 } else {
1223 return false;
1224 }
1225
1226 } else if (( common = commonType( t1, t2, env, need, have, open, widen ))) {
1227 // no exact unification, but common type
1228 auto c = shallowCopy(common.get());
1229 c->qualifiers = q1 | q2;
1230 common = c;
1231 return true;
1232 } else {
1233 return false;
1234 }
1235 }
1236
1237 ast::ptr<ast::Type> extractResultType( const ast::FunctionType * func ) {
1238 if ( func->returns.empty() ) return new ast::VoidType{};
1239 if ( func->returns.size() == 1 ) return func->returns[0];
1240
1241 std::vector<ast::ptr<ast::Type>> tys;
1242 for ( const auto & decl : func->returns ) {
1243 tys.emplace_back( decl );
1244 }
1245 return new ast::TupleType{ std::move(tys) };
1246 }
1247} // namespace ResolvExpr
1248
1249// Local Variables: //
1250// tab-width: 4 //
1251// mode: c++ //
1252// compile-command: "make install" //
1253// End: //
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