source: src/ResolvExpr/Unify.cc@ df00c78

ADT ast-experimental pthread-emulation
Last change on this file since df00c78 was 9d8124f, checked in by Fangren Yu <f37yu@…>, 4 years ago

fix some code that clearly does not accomplish the correct thing.
has no effect on tests; report if this changes anything
  • Property mode set to 100644
File size: 48.0 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 "FindOpenVars.h" // for findOpenVars
36#include "SynTree/LinkageSpec.h" // for C
37#include "SynTree/Constant.h" // for Constant
38#include "SynTree/Declaration.h" // for TypeDecl, TypeDecl::Data, Declarati...
39#include "SynTree/Expression.h" // for TypeExpr, Expression, ConstantExpr
40#include "SynTree/Mutator.h" // for Mutator
41#include "SynTree/Type.h" // for Type, TypeInstType, FunctionType
42#include "SynTree/Visitor.h" // for Visitor
43#include "Tuples/Tuples.h" // for isTtype
44#include "TypeEnvironment.h" // for EqvClass, AssertionSet, OpenVarSet
45#include "typeops.h" // for flatten, occurs, commonType
46
47namespace ast {
48 class SymbolTable;
49}
50
51namespace SymTab {
52class Indexer;
53} // namespace SymTab
54
55// #define DEBUG
56
57namespace ResolvExpr {
58
59 struct Unify_old : public WithShortCircuiting {
60 Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
61
62 bool get_result() const { return result; }
63
64 void previsit( BaseSyntaxNode * ) { visit_children = false; }
65
66 void postvisit( VoidType * voidType );
67 void postvisit( BasicType * basicType );
68 void postvisit( PointerType * pointerType );
69 void postvisit( ArrayType * arrayType );
70 void postvisit( ReferenceType * refType );
71 void postvisit( FunctionType * functionType );
72 void postvisit( StructInstType * aggregateUseType );
73 void postvisit( UnionInstType * aggregateUseType );
74 void postvisit( EnumInstType * aggregateUseType );
75 void postvisit( TraitInstType * aggregateUseType );
76 void postvisit( TypeInstType * aggregateUseType );
77 void postvisit( TupleType * tupleType );
78 void postvisit( VarArgsType * varArgsType );
79 void postvisit( ZeroType * zeroType );
80 void postvisit( OneType * oneType );
81
82 private:
83 template< typename RefType > void handleRefType( RefType *inst, Type *other );
84 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
85
86 bool result;
87 Type *type2; // inherited
88 TypeEnvironment &env;
89 AssertionSet &needAssertions;
90 AssertionSet &haveAssertions;
91 const OpenVarSet &openVars;
92 WidenMode widen;
93 const SymTab::Indexer &indexer;
94 };
95
96 /// Attempts an inexact unification of type1 and type2.
97 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
98 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common );
99 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
100
101 bool unifyExact(
102 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
103 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
104 WidenMode widen, const ast::SymbolTable & symtab );
105
106 bool typesCompatible( const Type * first, const Type * second, const SymTab::Indexer & indexer, const TypeEnvironment & env ) {
107 TypeEnvironment newEnv;
108 OpenVarSet openVars, closedVars; // added closedVars
109 AssertionSet needAssertions, haveAssertions;
110 Type * newFirst = first->clone(), * newSecond = second->clone();
111 env.apply( newFirst );
112 env.apply( newSecond );
113
114 // do we need to do this? Seems like we do, types should be able to be compatible if they
115 // have free variables that can unify
116 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
117 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
118
119 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
120 delete newFirst;
121 delete newSecond;
122 return result;
123 }
124
125 bool typesCompatible(
126 const ast::Type * first, const ast::Type * second, const ast::SymbolTable & symtab,
127 const ast::TypeEnvironment & env ) {
128 ast::TypeEnvironment newEnv;
129 ast::OpenVarSet open, closed;
130 ast::AssertionSet need, have;
131
132 ast::ptr<ast::Type> newFirst{ first }, newSecond{ second };
133 env.apply( newFirst );
134 env.apply( newSecond );
135
136 findOpenVars( newFirst, open, closed, need, have, FirstClosed );
137 findOpenVars( newSecond, open, closed, need, have, FirstOpen );
138
139 return unifyExact(newFirst, newSecond, newEnv, need, have, open, noWiden(), symtab );
140 }
141
142 bool typesCompatibleIgnoreQualifiers( const Type * first, const Type * second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
143 TypeEnvironment newEnv;
144 OpenVarSet openVars;
145 AssertionSet needAssertions, haveAssertions;
146 Type *newFirst = first->clone(), *newSecond = second->clone();
147 env.apply( newFirst );
148 env.apply( newSecond );
149 newFirst->get_qualifiers() = Type::Qualifiers();
150 newSecond->get_qualifiers() = Type::Qualifiers();
151
152 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
153 delete newFirst;
154 delete newSecond;
155 return result;
156 }
157
158 bool typesCompatibleIgnoreQualifiers(
159 const ast::Type * first, const ast::Type * second, const ast::SymbolTable & symtab,
160 const ast::TypeEnvironment & env ) {
161 ast::TypeEnvironment newEnv;
162 ast::OpenVarSet open;
163 ast::AssertionSet need, have;
164
165 ast::Type * newFirst = shallowCopy( first );
166 ast::Type * newSecond = shallowCopy( second );
167 newFirst ->qualifiers = {};
168 newSecond->qualifiers = {};
169 ast::ptr< ast::Type > t1_(newFirst );
170 ast::ptr< ast::Type > t2_(newSecond);
171
172 ast::ptr< ast::Type > subFirst = env.apply(newFirst).node;
173 ast::ptr< ast::Type > subSecond = env.apply(newSecond).node;
174
175 return unifyExact(
176 subFirst,
177 subSecond,
178 newEnv, need, have, open, noWiden(), symtab );
179 }
180
181 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
182 OpenVarSet closedVars;
183 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
184 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
185 Type *commonType = 0;
186 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
187 if ( commonType ) {
188 delete commonType;
189 } // if
190 return true;
191 } else {
192 return false;
193 } // if
194 }
195
196 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
197 OpenVarSet closedVars;
198 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
199 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
200 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
201 }
202
203 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
204#ifdef DEBUG
205 TypeEnvironment debugEnv( env );
206#endif
207 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
208 return false;
209 }
210
211 bool result;
212 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
213 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
214 OpenVarSet::const_iterator entry1, entry2;
215 if ( var1 ) {
216 entry1 = openVars.find( var1->get_name() );
217 } // if
218 if ( var2 ) {
219 entry2 = openVars.find( var2->get_name() );
220 } // if
221 bool isopen1 = var1 && ( entry1 != openVars.end() );
222 bool isopen2 = var2 && ( entry2 != openVars.end() );
223
224 if ( isopen1 && isopen2 ) {
225 if ( entry1->second.kind != entry2->second.kind ) {
226 result = false;
227 } else {
228 result = env.bindVarToVar(
229 var1, var2, TypeDecl::Data{ entry1->second, entry2->second }, needAssertions,
230 haveAssertions, openVars, widen, indexer );
231 }
232 } else if ( isopen1 ) {
233 result = env.bindVar( var1, type2, entry1->second, needAssertions, haveAssertions, openVars, widen, indexer );
234 } else if ( isopen2 ) { // TODO: swap widen values in call, since type positions are flipped?
235 result = env.bindVar( var2, type1, entry2->second, needAssertions, haveAssertions, openVars, widen, indexer );
236 } else {
237 PassVisitor<Unify_old> comparator( type2, env, needAssertions, haveAssertions, openVars, widen, indexer );
238 type1->accept( comparator );
239 result = comparator.pass.get_result();
240 } // if
241#ifdef DEBUG
242 std::cerr << "============ unifyExact" << std::endl;
243 std::cerr << "type1 is ";
244 type1->print( std::cerr );
245 std::cerr << std::endl << "type2 is ";
246 type2->print( std::cerr );
247 std::cerr << std::endl << "openVars are ";
248 printOpenVarSet( openVars, std::cerr, 8 );
249 std::cerr << std::endl << "input env is " << std::endl;
250 debugEnv.print( std::cerr, 8 );
251 std::cerr << std::endl << "result env is " << std::endl;
252 env.print( std::cerr, 8 );
253 std::cerr << "result is " << result << std::endl;
254#endif
255 return result;
256 }
257
258 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
259 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
260 }
261
262 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common ) {
263 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
264 type1->get_qualifiers() = Type::Qualifiers();
265 type2->get_qualifiers() = Type::Qualifiers();
266 bool result;
267#ifdef DEBUG
268 std::cerr << "unifyInexact type 1 is ";
269 type1->print( std::cerr );
270 std::cerr << " type 2 is ";
271 type2->print( std::cerr );
272 std::cerr << std::endl;
273#endif
274 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widen, indexer ) ) {
275#ifdef DEBUG
276 std::cerr << "unifyInexact: no exact unification found" << std::endl;
277#endif
278 if ( ( common = commonType( type1, type2, widen.first, widen.second, indexer, env, openVars ) ) ) {
279 common->tq = tq1.unify( tq2 );
280#ifdef DEBUG
281 std::cerr << "unifyInexact: common type is ";
282 common->print( std::cerr );
283 std::cerr << std::endl;
284#endif
285 result = true;
286 } else {
287#ifdef DEBUG
288 std::cerr << "unifyInexact: no common type found" << std::endl;
289#endif
290 result = false;
291 } // if
292 } else {
293 if ( tq1 != tq2 ) {
294 if ( ( tq1 > tq2 || widen.first ) && ( tq2 > tq1 || widen.second ) ) {
295 common = type1->clone();
296 common->tq = tq1.unify( tq2 );
297 result = true;
298 } else {
299 result = false;
300 } // if
301 } else {
302 common = type1->clone();
303 common->tq = tq1.unify( tq2 );
304 result = true;
305 } // if
306 } // if
307 type1->get_qualifiers() = tq1;
308 type2->get_qualifiers() = tq2;
309 return result;
310 }
311
312 Unify_old::Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer )
313 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widen( widen ), indexer( indexer ) {
314 }
315
316 void Unify_old::postvisit( __attribute__((unused)) VoidType *voidType) {
317 result = dynamic_cast< VoidType* >( type2 );
318 }
319
320 void Unify_old::postvisit(BasicType *basicType) {
321 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
322 result = basicType->get_kind() == otherBasic->get_kind();
323 } // if
324 }
325
326 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
327 AssertionSet::iterator i = assertions.find( assert );
328 if ( i != assertions.end() ) {
329 i->second.isUsed = true;
330 } // if
331 }
332
333 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
334 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
335 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
336 markAssertionSet( assertion1, *assert );
337 markAssertionSet( assertion2, *assert );
338 } // for
339 } // for
340 }
341
342 void Unify_old::postvisit(PointerType *pointerType) {
343 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
344 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
345 markAssertions( haveAssertions, needAssertions, pointerType );
346 markAssertions( haveAssertions, needAssertions, otherPointer );
347 } // if
348 }
349
350 void Unify_old::postvisit(ReferenceType *refType) {
351 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
352 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
353 markAssertions( haveAssertions, needAssertions, refType );
354 markAssertions( haveAssertions, needAssertions, otherRef );
355 } // if
356 }
357
358 void Unify_old::postvisit(ArrayType *arrayType) {
359 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
360 // to unify, array types must both be VLA or both not VLA
361 // and must both have a dimension expression or not have a dimension
362 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
363
364 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
365 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
366 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
367 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
368 // see C11 Reference Manual 6.7.6.2.6
369 // two array types with size specifiers that are integer constant expressions are
370 // compatible if both size specifiers have the same constant value
371 if ( ce1 && ce2 ) {
372 Constant * c1 = ce1->get_constant();
373 Constant * c2 = ce2->get_constant();
374
375 if ( c1->get_value() != c2->get_value() ) {
376 // does not unify if the dimension is different
377 return;
378 }
379 }
380 }
381
382 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
383 } // if
384 }
385
386 template< typename Iterator, typename Func >
387 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
388 std::list< Type * > types;
389 for ( ; begin != end; ++begin ) {
390 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
391 flatten( toType( *begin ), back_inserter( types ) );
392 }
393 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
394 }
395
396 template< typename Iterator1, typename Iterator2 >
397 bool unifyTypeList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
398 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
399 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
400 Type * t1 = (*list1Begin)->get_type();
401 Type * t2 = (*list2Begin)->get_type();
402 bool isTtype1 = Tuples::isTtype( t1 );
403 bool isTtype2 = Tuples::isTtype( t2 );
404 // xxx - assumes ttype must be last parameter
405 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
406 if ( isTtype1 && ! isTtype2 ) {
407 // combine all of the things in list2, then unify
408 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
409 } else if ( isTtype2 && ! isTtype1 ) {
410 // combine all of the things in list1, then unify
411 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
412 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
413 return false;
414 } // if
415 } // for
416 // 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
417 if ( list1Begin != list1End ) {
418 // try unifying empty tuple type with ttype
419 Type * t1 = (*list1Begin)->get_type();
420 if ( Tuples::isTtype( t1 ) ) {
421 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
422 } else return false;
423 } else if ( list2Begin != list2End ) {
424 // try unifying empty tuple type with ttype
425 Type * t2 = (*list2Begin)->get_type();
426 if ( Tuples::isTtype( t2 ) ) {
427 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
428 } else return false;
429 } else {
430 return true;
431 } // if
432 }
433
434 /// Finds ttypes and replaces them with their expansion, if known.
435 /// This needs to be done so that satisfying ttype assertions is easier.
436 /// If this isn't done then argument lists can have wildly different
437 /// size and structure, when they should be compatible.
438 struct TtypeExpander_old : public WithShortCircuiting {
439 TypeEnvironment & tenv;
440 TtypeExpander_old( TypeEnvironment & tenv ) : tenv( tenv ) {}
441 void premutate( TypeInstType * ) { visit_children = false; }
442 Type * postmutate( TypeInstType * typeInst ) {
443 if ( const EqvClass *eqvClass = tenv.lookup( typeInst->get_name() ) ) {
444 // expand ttype parameter into its actual type
445 if ( eqvClass->data.kind == TypeDecl::Ttype && eqvClass->type ) {
446 delete typeInst;
447 return eqvClass->type->clone();
448 }
449 }
450 return typeInst;
451 }
452 };
453
454 /// flattens a list of declarations, so that each tuple type has a single declaration.
455 /// makes use of TtypeExpander to ensure ttypes are flat as well.
456 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
457 dst.clear();
458 for ( DeclarationWithType * dcl : src ) {
459 PassVisitor<TtypeExpander_old> expander( env );
460 dcl->acceptMutator( expander );
461 std::list< Type * > types;
462 flatten( dcl->get_type(), back_inserter( types ) );
463 for ( Type * t : types ) {
464 // 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.
465 // 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.
466 t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic);
467
468 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
469 }
470 delete dcl;
471 }
472 }
473
474 void Unify_old::postvisit(FunctionType *functionType) {
475 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
476 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
477 // flatten the parameter lists for both functions so that tuple structure
478 // doesn't affect unification. Must be a clone so that the types don't change.
479 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
480 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
481 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
482 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
483
484 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
485 if (
486 (flatFunc->parameters.size() == flatOther->parameters.size() &&
487 flatFunc->returnVals.size() == flatOther->returnVals.size())
488 || flatFunc->isTtype()
489 || flatOther->isTtype()
490 ) {
491 if ( unifyTypeList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
492 if ( unifyTypeList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->returnVals.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
493
494 // the original types must be used in mark assertions, since pointer comparisons are used
495 markAssertions( haveAssertions, needAssertions, functionType );
496 markAssertions( haveAssertions, needAssertions, otherFunction );
497
498 result = true;
499 } // if
500 } // if
501 } // if
502 } // if
503 }
504
505 template< typename RefType >
506 void Unify_old::handleRefType( RefType *inst, Type *other ) {
507 // check that other type is compatible and named the same
508 RefType *otherStruct = dynamic_cast< RefType* >( other );
509 result = otherStruct && inst->name == otherStruct->name;
510 }
511
512 template< typename RefType >
513 void Unify_old::handleGenericRefType( RefType *inst, Type *other ) {
514 // Check that other type is compatible and named the same
515 handleRefType( inst, other );
516 if ( ! result ) return;
517 // Check that parameters of types unify, if any
518 std::list< Expression* > params = inst->parameters;
519 std::list< Expression* > otherParams = ((RefType*)other)->parameters;
520
521 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
522 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
523 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
524 assertf(param, "Aggregate parameters should be type expressions");
525 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
526 assertf(otherParam, "Aggregate parameters should be type expressions");
527
528 Type* paramTy = param->get_type();
529 Type* otherParamTy = otherParam->get_type();
530
531 bool tupleParam = Tuples::isTtype( paramTy );
532 bool otherTupleParam = Tuples::isTtype( otherParamTy );
533
534 if ( tupleParam && otherTupleParam ) {
535 ++it; ++jt; // skip ttype parameters for break
536 } else if ( tupleParam ) {
537 // bundle other parameters into tuple to match
538 std::list< Type * > binderTypes;
539
540 do {
541 binderTypes.push_back( otherParam->get_type()->clone() );
542 ++jt;
543
544 if ( jt == otherParams.end() ) break;
545
546 otherParam = dynamic_cast< TypeExpr* >(*jt);
547 assertf(otherParam, "Aggregate parameters should be type expressions");
548 } while (true);
549
550 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
551 ++it; // skip ttype parameter for break
552 } else if ( otherTupleParam ) {
553 // bundle parameters into tuple to match other
554 std::list< Type * > binderTypes;
555
556 do {
557 binderTypes.push_back( param->get_type()->clone() );
558 ++it;
559
560 if ( it == params.end() ) break;
561
562 param = dynamic_cast< TypeExpr* >(*it);
563 assertf(param, "Aggregate parameters should be type expressions");
564 } while (true);
565
566 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
567 ++jt; // skip ttype parameter for break
568 }
569
570 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
571 result = false;
572 return;
573 }
574
575 // ttype parameter should be last
576 if ( tupleParam || otherTupleParam ) break;
577 }
578 result = ( it == params.end() && jt == otherParams.end() );
579 }
580
581 void Unify_old::postvisit(StructInstType *structInst) {
582 handleGenericRefType( structInst, type2 );
583 }
584
585 void Unify_old::postvisit(UnionInstType *unionInst) {
586 handleGenericRefType( unionInst, type2 );
587 }
588
589 void Unify_old::postvisit(EnumInstType *enumInst) {
590 handleRefType( enumInst, type2 );
591 }
592
593 void Unify_old::postvisit(TraitInstType *contextInst) {
594 handleRefType( contextInst, type2 );
595 }
596
597 void Unify_old::postvisit(TypeInstType *typeInst) {
598 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
599 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
600 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
601 result = true;
602/// } else {
603/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
604/// if ( nt ) {
605/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
606/// assert( type );
607/// if ( type->get_base() ) {
608/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
609/// }
610/// }
611 } // if
612 }
613
614 template< typename Iterator1, typename Iterator2 >
615 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
616 auto get_type = [](Type * t) { return t; };
617 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
618 Type * t1 = *list1Begin;
619 Type * t2 = *list2Begin;
620 bool isTtype1 = Tuples::isTtype( t1 );
621 bool isTtype2 = Tuples::isTtype( t2 );
622 // xxx - assumes ttype must be last parameter
623 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
624 if ( isTtype1 && ! isTtype2 ) {
625 // combine all of the things in list2, then unify
626 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
627 } else if ( isTtype2 && ! isTtype1 ) {
628 // combine all of the things in list1, then unify
629 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
630 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
631 return false;
632 } // if
633
634 } // for
635 if ( list1Begin != list1End ) {
636 // try unifying empty tuple type with ttype
637 Type * t1 = *list1Begin;
638 if ( Tuples::isTtype( t1 ) ) {
639 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
640 } else return false;
641 } else if ( list2Begin != list2End ) {
642 // try unifying empty tuple type with ttype
643 Type * t2 = *list2Begin;
644 if ( Tuples::isTtype( t2 ) ) {
645 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
646 } else return false;
647 } else {
648 return true;
649 } // if
650 }
651
652 void Unify_old::postvisit(TupleType *tupleType) {
653 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
654 std::unique_ptr<TupleType> flat1( tupleType->clone() );
655 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
656 std::list<Type *> types1, types2;
657
658 PassVisitor<TtypeExpander_old> expander( env );
659 flat1->acceptMutator( expander );
660 flat2->acceptMutator( expander );
661
662 flatten( flat1.get(), back_inserter( types1 ) );
663 flatten( flat2.get(), back_inserter( types2 ) );
664
665 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
666 } // if
667 }
668
669 void Unify_old::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) {
670 result = dynamic_cast< VarArgsType* >( type2 );
671 }
672
673 void Unify_old::postvisit( __attribute__((unused)) ZeroType *zeroType ) {
674 result = dynamic_cast< ZeroType* >( type2 );
675 }
676
677 void Unify_old::postvisit( __attribute__((unused)) OneType *oneType ) {
678 result = dynamic_cast< OneType* >( type2 );
679 }
680
681 Type * extractResultType( FunctionType * function ) {
682 if ( function->get_returnVals().size() == 0 ) {
683 return new VoidType( Type::Qualifiers() );
684 } else if ( function->get_returnVals().size() == 1 ) {
685 return function->get_returnVals().front()->get_type()->clone();
686 } else {
687 std::list< Type * > types;
688 for ( DeclarationWithType * decl : function->get_returnVals() ) {
689 types.push_back( decl->get_type()->clone() );
690 } // for
691 return new TupleType( Type::Qualifiers(), types );
692 }
693 }
694
695 class Unify_new final : public ast::WithShortCircuiting {
696 const ast::Type * type2;
697 ast::TypeEnvironment & tenv;
698 ast::AssertionSet & need;
699 ast::AssertionSet & have;
700 const ast::OpenVarSet & open;
701 WidenMode widen;
702 const ast::SymbolTable & symtab;
703 public:
704 static size_t traceId;
705 bool result;
706
707 Unify_new(
708 const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need,
709 ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen,
710 const ast::SymbolTable & symtab )
711 : type2(type2), tenv(env), need(need), have(have), open(open), widen(widen),
712 symtab(symtab), result(false) {}
713
714 void previsit( const ast::Node * ) { visit_children = false; }
715
716 void postvisit( const ast::VoidType * ) {
717 result = dynamic_cast< const ast::VoidType * >( type2 );
718 }
719
720 void postvisit( const ast::BasicType * basic ) {
721 if ( auto basic2 = dynamic_cast< const ast::BasicType * >( type2 ) ) {
722 result = basic->kind == basic2->kind;
723 }
724 }
725
726 void postvisit( const ast::PointerType * pointer ) {
727 if ( auto pointer2 = dynamic_cast< const ast::PointerType * >( type2 ) ) {
728 result = unifyExact(
729 pointer->base, pointer2->base, tenv, need, have, open,
730 noWiden(), symtab );
731 }
732 }
733
734 void postvisit( const ast::ArrayType * array ) {
735 auto array2 = dynamic_cast< const ast::ArrayType * >( type2 );
736 if ( ! array2 ) return;
737
738 // to unify, array types must both be VLA or both not VLA and both must have a
739 // dimension expression or not have a dimension
740 if ( array->isVarLen != array2->isVarLen ) return;
741 if ( ! array->isVarLen && ! array2->isVarLen
742 && array->dimension && array2->dimension ) {
743 auto ce1 = array->dimension.as< ast::ConstantExpr >();
744 auto ce2 = array2->dimension.as< ast::ConstantExpr >();
745
746 // see C11 Reference Manual 6.7.6.2.6
747 // two array types with size specifiers that are integer constant expressions are
748 // compatible if both size specifiers have the same constant value
749 if ( ce1 && ce2 && ce1->intValue() != ce2->intValue() ) return;
750 }
751
752 result = unifyExact(
753 array->base, array2->base, tenv, need, have, open, noWiden(),
754 symtab );
755 }
756
757 void postvisit( const ast::ReferenceType * ref ) {
758 if ( auto ref2 = dynamic_cast< const ast::ReferenceType * >( type2 ) ) {
759 result = unifyExact(
760 ref->base, ref2->base, tenv, need, have, open, noWiden(),
761 symtab );
762 }
763 }
764
765 private:
766 /// Replaces ttype variables with their bound types.
767 /// If this isn't done when satifying ttype assertions, then argument lists can have
768 /// different size and structure when they should be compatible.
769 struct TtypeExpander_new : public ast::WithShortCircuiting, public ast::PureVisitor {
770 ast::TypeEnvironment & tenv;
771
772 TtypeExpander_new( ast::TypeEnvironment & env ) : tenv( env ) {}
773
774 const ast::Type * postvisit( const ast::TypeInstType * typeInst ) {
775 if ( const ast::EqvClass * clz = tenv.lookup( *typeInst ) ) {
776 // expand ttype parameter into its actual type
777 if ( clz->data.kind == ast::TypeDecl::Ttype && clz->bound ) {
778 return clz->bound;
779 }
780 }
781 return typeInst;
782 }
783 };
784
785 /// returns flattened version of `src`
786 static std::vector< ast::ptr< ast::Type > > flattenList(
787 const std::vector< ast::ptr< ast::Type > > & src, ast::TypeEnvironment & env
788 ) {
789 std::vector< ast::ptr< ast::Type > > dst;
790 dst.reserve( src.size() );
791 for ( const auto & d : src ) {
792 ast::Pass<TtypeExpander_new> expander{ env };
793 // TtypeExpander pass is impure (may mutate nodes in place)
794 // need to make nodes shared to prevent accidental mutation
795 ast::ptr<ast::Type> dc = d->accept(expander);
796 auto types = flatten( dc );
797 for ( ast::ptr< ast::Type > & t : types ) {
798 // outermost const, volatile, _Atomic qualifiers in parameters should not play
799 // a role in the unification of function types, since they do not determine
800 // whether a function is callable.
801 // NOTE: **must** consider at least mutex qualifier, since functions can be
802 // overloaded on outermost mutex and a mutex function has different
803 // requirements than a non-mutex function
804 remove_qualifiers( t, ast::CV::Const | ast::CV::Volatile | ast::CV::Atomic );
805 dst.emplace_back( t );
806 }
807 }
808 return dst;
809 }
810
811 /// Creates a tuple type based on a list of DeclWithType
812 template< typename Iter >
813 static const ast::Type * tupleFromTypes( Iter crnt, Iter end ) {
814 std::vector< ast::ptr< ast::Type > > types;
815 while ( crnt != end ) {
816 // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure
817 // that this results in a flat tuple
818 flatten( *crnt, types );
819
820 ++crnt;
821 }
822
823 return new ast::TupleType{ std::move(types) };
824 }
825
826 template< typename Iter >
827 static bool unifyTypeList(
828 Iter crnt1, Iter end1, Iter crnt2, Iter end2, ast::TypeEnvironment & env,
829 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
830 const ast::SymbolTable & symtab
831 ) {
832 while ( crnt1 != end1 && crnt2 != end2 ) {
833 const ast::Type * t1 = *crnt1;
834 const ast::Type * t2 = *crnt2;
835 bool isTuple1 = Tuples::isTtype( t1 );
836 bool isTuple2 = Tuples::isTtype( t2 );
837
838 // assumes here that ttype *must* be last parameter
839 if ( isTuple1 && ! isTuple2 ) {
840 // combine remainder of list2, then unify
841 return unifyExact(
842 t1, tupleFromTypes( crnt2, end2 ), env, need, have, open,
843 noWiden(), symtab );
844 } else if ( ! isTuple1 && isTuple2 ) {
845 // combine remainder of list1, then unify
846 return unifyExact(
847 tupleFromTypes( crnt1, end1 ), t2, env, need, have, open,
848 noWiden(), symtab );
849 }
850
851 if ( ! unifyExact(
852 t1, t2, env, need, have, open, noWiden(), symtab )
853 ) return false;
854
855 ++crnt1; ++crnt2;
856 }
857
858 // May get to the end of one argument list before the other. This is only okay if the
859 // other is a ttype
860 if ( crnt1 != end1 ) {
861 // try unifying empty tuple with ttype
862 const ast::Type * t1 = *crnt1;
863 if ( ! Tuples::isTtype( t1 ) ) return false;
864 return unifyExact(
865 t1, tupleFromTypes( crnt2, end2 ), env, need, have, open,
866 noWiden(), symtab );
867 } else if ( crnt2 != end2 ) {
868 // try unifying empty tuple with ttype
869 const ast::Type * t2 = *crnt2;
870 if ( ! Tuples::isTtype( t2 ) ) return false;
871 return unifyExact(
872 tupleFromTypes( crnt1, end1 ), t2, env, need, have, open,
873 noWiden(), symtab );
874 }
875
876 return true;
877 }
878
879 static bool unifyTypeList(
880 const std::vector< ast::ptr< ast::Type > > & list1,
881 const std::vector< ast::ptr< ast::Type > > & list2,
882 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
883 const ast::OpenVarSet & open, const ast::SymbolTable & symtab
884 ) {
885 return unifyTypeList(
886 list1.begin(), list1.end(), list2.begin(), list2.end(), env, need, have, open,
887 symtab );
888 }
889
890 static void markAssertionSet( ast::AssertionSet & assns, const ast::VariableExpr * assn ) {
891 auto i = assns.find( assn );
892 if ( i != assns.end() ) {
893 i->second.isUsed = true;
894 }
895 }
896
897 /// mark all assertions in `type` used in both `assn1` and `assn2`
898 static void markAssertions(
899 ast::AssertionSet & assn1, ast::AssertionSet & assn2,
900 const ast::FunctionType * type
901 ) {
902 for ( auto & assert : type->assertions ) {
903 markAssertionSet( assn1, assert );
904 markAssertionSet( assn2, assert );
905 }
906 }
907
908 public:
909 void postvisit( const ast::FunctionType * func ) {
910 auto func2 = dynamic_cast< const ast::FunctionType * >( type2 );
911 if ( ! func2 ) return;
912
913 if ( func->isVarArgs != func2->isVarArgs ) return;
914
915 // Flatten the parameter lists for both functions so that tuple structure does not
916 // affect unification. Does not actually mutate function parameters.
917 auto params = flattenList( func->params, tenv );
918 auto params2 = flattenList( func2->params, tenv );
919
920 // sizes don't have to match if ttypes are involved; need to be more precise w.r.t.
921 // where the ttype is to prevent errors
922 if (
923 ( params.size() != params2.size() || func->returns.size() != func2->returns.size() )
924 && ! func->isTtype()
925 && ! func2->isTtype()
926 ) return;
927
928 if ( ! unifyTypeList( params, params2, tenv, need, have, open, symtab ) ) return;
929 if ( ! unifyTypeList(
930 func->returns, func2->returns, tenv, need, have, open, symtab ) ) return;
931
932 markAssertions( have, need, func );
933 markAssertions( have, need, func2 );
934
935 result = true;
936 }
937
938 private:
939 // Returns: other, cast as XInstType
940 // Assigns this->result: whether types are compatible (up to generic parameters)
941 template< typename XInstType >
942 const XInstType * handleRefType( const XInstType * inst, const ast::Type * other ) {
943 // check that the other type is compatible and named the same
944 auto otherInst = dynamic_cast< const XInstType * >( other );
945 if (otherInst && inst->name == otherInst->name) this->result = otherInst;
946 return otherInst;
947 }
948
949 /// Creates a tuple type based on a list of TypeExpr
950 template< typename Iter >
951 static const ast::Type * tupleFromExprs(
952 const ast::TypeExpr * param, Iter & crnt, Iter end, ast::CV::Qualifiers qs
953 ) {
954 std::vector< ast::ptr< ast::Type > > types;
955 do {
956 types.emplace_back( param->type );
957
958 ++crnt;
959 if ( crnt == end ) break;
960 param = strict_dynamic_cast< const ast::TypeExpr * >( crnt->get() );
961 } while(true);
962
963 return new ast::TupleType{ std::move(types), qs };
964 }
965
966 template< typename XInstType >
967 void handleGenericRefType( const XInstType * inst, const ast::Type * other ) {
968 // check that other type is compatible and named the same
969 const XInstType * otherInst = handleRefType( inst, other );
970 if ( ! this->result ) return;
971
972 // check that parameters of types unify, if any
973 const std::vector< ast::ptr< ast::Expr > > & params = inst->params;
974 const std::vector< ast::ptr< ast::Expr > > & params2 = otherInst->params;
975
976 auto it = params.begin();
977 auto jt = params2.begin();
978 for ( ; it != params.end() && jt != params2.end(); ++it, ++jt ) {
979 auto param = strict_dynamic_cast< const ast::TypeExpr * >( it->get() );
980 auto param2 = strict_dynamic_cast< const ast::TypeExpr * >( jt->get() );
981
982 ast::ptr< ast::Type > pty = param->type;
983 ast::ptr< ast::Type > pty2 = param2->type;
984
985 bool isTuple = Tuples::isTtype( pty );
986 bool isTuple2 = Tuples::isTtype( pty2 );
987
988 if ( isTuple && isTuple2 ) {
989 ++it; ++jt; // skip ttype parameters before break
990 } else if ( isTuple ) {
991 // bundle remaining params into tuple
992 pty2 = tupleFromExprs( param2, jt, params2.end(), pty->qualifiers );
993 ++it; // skip ttype parameter for break
994 } else if ( isTuple2 ) {
995 // bundle remaining params into tuple
996 pty = tupleFromExprs( param, it, params.end(), pty2->qualifiers );
997 ++jt; // skip ttype parameter for break
998 }
999
1000 if ( ! unifyExact(
1001 pty, pty2, tenv, need, have, open, noWiden(), symtab ) ) {
1002 result = false;
1003 return;
1004 }
1005
1006 // ttype parameter should be last
1007 if ( isTuple || isTuple2 ) break;
1008 }
1009 result = it == params.end() && jt == params2.end();
1010 }
1011
1012 public:
1013 void postvisit( const ast::StructInstType * aggrType ) {
1014 handleGenericRefType( aggrType, type2 );
1015 }
1016
1017 void postvisit( const ast::UnionInstType * aggrType ) {
1018 handleGenericRefType( aggrType, type2 );
1019 }
1020
1021 void postvisit( const ast::EnumInstType * aggrType ) {
1022 handleRefType( aggrType, type2 );
1023 }
1024
1025 void postvisit( const ast::TraitInstType * aggrType ) {
1026 handleRefType( aggrType, type2 );
1027 }
1028
1029 void postvisit( const ast::TypeInstType * typeInst ) {
1030 assert( open.find( *typeInst ) == open.end() );
1031 handleRefType( typeInst, type2 );
1032 }
1033
1034 private:
1035 /// Creates a tuple type based on a list of Type
1036 static const ast::Type * tupleFromTypes(
1037 const std::vector< ast::ptr< ast::Type > > & tys
1038 ) {
1039 std::vector< ast::ptr< ast::Type > > out;
1040 for ( const ast::Type * ty : tys ) {
1041 // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure
1042 // that this results in a flat tuple
1043 flatten( ty, out );
1044 }
1045
1046 return new ast::TupleType{ std::move(out) };
1047 }
1048
1049 static bool unifyList(
1050 const std::vector< ast::ptr< ast::Type > > & list1,
1051 const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env,
1052 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1053 const ast::SymbolTable & symtab
1054 ) {
1055 auto crnt1 = list1.begin();
1056 auto crnt2 = list2.begin();
1057 while ( crnt1 != list1.end() && crnt2 != list2.end() ) {
1058 const ast::Type * t1 = *crnt1;
1059 const ast::Type * t2 = *crnt2;
1060 bool isTuple1 = Tuples::isTtype( t1 );
1061 bool isTuple2 = Tuples::isTtype( t2 );
1062
1063 // assumes ttype must be last parameter
1064 if ( isTuple1 && ! isTuple2 ) {
1065 // combine entirety of list2, then unify
1066 return unifyExact(
1067 t1, tupleFromTypes( list2 ), env, need, have, open,
1068 noWiden(), symtab );
1069 } else if ( ! isTuple1 && isTuple2 ) {
1070 // combine entirety of list1, then unify
1071 return unifyExact(
1072 tupleFromTypes( list1 ), t2, env, need, have, open,
1073 noWiden(), symtab );
1074 }
1075
1076 if ( ! unifyExact(
1077 t1, t2, env, need, have, open, noWiden(), symtab )
1078 ) return false;
1079
1080 ++crnt1; ++crnt2;
1081 }
1082
1083 if ( crnt1 != list1.end() ) {
1084 // try unifying empty tuple type with ttype
1085 const ast::Type * t1 = *crnt1;
1086 if ( ! Tuples::isTtype( t1 ) ) return false;
1087 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1088 // from Rob's code
1089 return unifyExact(
1090 t1, tupleFromTypes( list2 ), env, need, have, open,
1091 noWiden(), symtab );
1092 } else if ( crnt2 != list2.end() ) {
1093 // try unifying empty tuple with ttype
1094 const ast::Type * t2 = *crnt2;
1095 if ( ! Tuples::isTtype( t2 ) ) return false;
1096 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1097 // from Rob's code
1098 return unifyExact(
1099 tupleFromTypes( list1 ), t2, env, need, have, open,
1100 noWiden(), symtab );
1101 }
1102
1103 return true;
1104 }
1105
1106 public:
1107 void postvisit( const ast::TupleType * tuple ) {
1108 auto tuple2 = dynamic_cast< const ast::TupleType * >( type2 );
1109 if ( ! tuple2 ) return;
1110
1111 ast::Pass<TtypeExpander_new> expander{ tenv };
1112
1113 const ast::Type * flat = tuple->accept( expander );
1114 const ast::Type * flat2 = tuple2->accept( expander );
1115
1116 auto types = flatten( flat );
1117 auto types2 = flatten( flat2 );
1118
1119 result = unifyList( types, types2, tenv, need, have, open, symtab );
1120 }
1121
1122 void postvisit( const ast::VarArgsType * ) {
1123 result = dynamic_cast< const ast::VarArgsType * >( type2 );
1124 }
1125
1126 void postvisit( const ast::ZeroType * ) {
1127 result = dynamic_cast< const ast::ZeroType * >( type2 );
1128 }
1129
1130 void postvisit( const ast::OneType * ) {
1131 result = dynamic_cast< const ast::OneType * >( type2 );
1132 }
1133
1134 private:
1135 template< typename RefType > void handleRefType( RefType *inst, Type *other );
1136 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
1137 };
1138
1139 // size_t Unify_new::traceId = Stats::Heap::new_stacktrace_id("Unify_new");
1140 bool unify(
1141 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1142 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1143 ast::OpenVarSet & open, const ast::SymbolTable & symtab
1144 ) {
1145 ast::ptr<ast::Type> common;
1146 return unify( type1, type2, env, need, have, open, symtab, common );
1147 }
1148
1149 bool unify(
1150 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1151 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1152 ast::OpenVarSet & open, const ast::SymbolTable & symtab, ast::ptr<ast::Type> & common
1153 ) {
1154 ast::OpenVarSet closed;
1155 findOpenVars( type1, open, closed, need, have, FirstClosed );
1156 findOpenVars( type2, open, closed, need, have, FirstOpen );
1157 return unifyInexact(
1158 type1, type2, env, need, have, open, WidenMode{ true, true }, symtab, common );
1159 }
1160
1161 bool unifyExact(
1162 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
1163 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1164 WidenMode widen, const ast::SymbolTable & symtab
1165 ) {
1166 if ( type1->qualifiers != type2->qualifiers ) return false;
1167
1168 auto var1 = dynamic_cast< const ast::TypeInstType * >( type1 );
1169 auto var2 = dynamic_cast< const ast::TypeInstType * >( type2 );
1170 ast::OpenVarSet::const_iterator
1171 entry1 = var1 ? open.find( *var1 ) : open.end(),
1172 entry2 = var2 ? open.find( *var2 ) : open.end();
1173 bool isopen1 = entry1 != open.end();
1174 bool isopen2 = entry2 != open.end();
1175
1176 if ( isopen1 && isopen2 ) {
1177 if ( entry1->second.kind != entry2->second.kind ) return false;
1178 return env.bindVarToVar(
1179 var1, var2, ast::TypeDecl::Data{ entry1->second, entry2->second }, need, have,
1180 open, widen, symtab );
1181 } else if ( isopen1 ) {
1182 return env.bindVar( var1, type2, entry1->second, need, have, open, widen, symtab );
1183 } else if ( isopen2 ) {
1184 return env.bindVar( var2, type1, entry2->second, need, have, open, widen, symtab );
1185 } else {
1186 ast::Pass<Unify_new> comparator{ type2, env, need, have, open, widen, symtab };
1187 type1->accept( comparator );
1188 return comparator.core.result;
1189 }
1190 }
1191
1192 bool unifyInexact(
1193 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1194 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1195 const ast::OpenVarSet & open, WidenMode widen, const ast::SymbolTable & symtab,
1196 ast::ptr<ast::Type> & common
1197 ) {
1198 ast::CV::Qualifiers q1 = type1->qualifiers, q2 = type2->qualifiers;
1199
1200 // force t1 and t2 to be cloned if their qualifiers must be stripped, so that type1 and
1201 // type2 are left unchanged; calling convention forces type{1,2}->strong_ref >= 1
1202 ast::Type * t1 = shallowCopy(type1.get());
1203 ast::Type * t2 = shallowCopy(type2.get());
1204 t1->qualifiers = {};
1205 t2->qualifiers = {};
1206 ast::ptr< ast::Type > t1_(t1);
1207 ast::ptr< ast::Type > t2_(t2);
1208
1209 if ( unifyExact( t1, t2, env, need, have, open, widen, symtab ) ) {
1210 // if exact unification on unqualified types, try to merge qualifiers
1211 if ( q1 == q2 || ( ( q1 > q2 || widen.first ) && ( q2 > q1 || widen.second ) ) ) {
1212 t1->qualifiers = q1 | q2;
1213 common = t1;
1214 return true;
1215 } else {
1216 return false;
1217 }
1218
1219 } else if (( common = commonType( t1, t2, widen, symtab, env, open ) )) {
1220 // no exact unification, but common type
1221 auto c = shallowCopy(common.get());
1222 c->qualifiers = q1 | q2;
1223 common = c;
1224 return true;
1225 } else {
1226 return false;
1227 }
1228 }
1229
1230 ast::ptr<ast::Type> extractResultType( const ast::FunctionType * func ) {
1231 if ( func->returns.empty() ) return new ast::VoidType{};
1232 if ( func->returns.size() == 1 ) return func->returns[0];
1233
1234 std::vector<ast::ptr<ast::Type>> tys;
1235 for ( const auto & decl : func->returns ) {
1236 tys.emplace_back( decl );
1237 }
1238 return new ast::TupleType{ std::move(tys) };
1239 }
1240} // namespace ResolvExpr
1241
1242// Local Variables: //
1243// tab-width: 4 //
1244// mode: c++ //
1245// compile-command: "make install" //
1246// End: //
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