source: src/ResolvExpr/Unify.cc@ affb51b

ADT ast-experimental
Last change on this file since affb51b was 5d8dae7, checked in by Andrew Beach <ajbeach@…>, 3 years ago

Used Pass::read in Unify in one place.
  • Property mode set to 100644
File size: 47.6 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 if ( auto temp = dynamic_cast<const ast::EnumInstType *>(first) ) {
168 if ( !dynamic_cast< const ast::EnumInstType * >( second ) ) {
169 const ast::EnumDecl * baseEnum = dynamic_cast<const ast::EnumDecl *>(temp->base.get());
170 if ( auto t = baseEnum->base.get() ) {
171 newFirst = ast::shallowCopy( t );
172 }
173 }
174 } else if ( auto temp = dynamic_cast<const ast::EnumInstType *>(second) ) {
175 const ast::EnumDecl * baseEnum = dynamic_cast<const ast::EnumDecl *>(temp->base.get());
176 if ( auto t = baseEnum->base.get() ) {
177 newSecond = ast::shallowCopy( t );
178 }
179 }
180
181 newFirst ->qualifiers = {};
182 newSecond->qualifiers = {};
183 ast::ptr< ast::Type > t1_(newFirst );
184 ast::ptr< ast::Type > t2_(newSecond);
185
186 ast::ptr< ast::Type > subFirst = env.apply(newFirst).node;
187 ast::ptr< ast::Type > subSecond = env.apply(newSecond).node;
188
189 return unifyExact(
190 subFirst,
191 subSecond,
192 newEnv, need, have, open, noWiden(), symtab );
193 }
194
195 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
196 OpenVarSet closedVars;
197 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
198 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
199 Type *commonType = 0;
200 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
201 if ( commonType ) {
202 delete commonType;
203 } // if
204 return true;
205 } else {
206 return false;
207 } // if
208 }
209
210 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
211 OpenVarSet closedVars;
212 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
213 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
214 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
215 }
216
217 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
218#ifdef DEBUG
219 TypeEnvironment debugEnv( env );
220#endif
221 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
222 return false;
223 }
224
225 bool result;
226 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
227 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
228 OpenVarSet::const_iterator entry1, entry2;
229 if ( var1 ) {
230 entry1 = openVars.find( var1->get_name() );
231 } // if
232 if ( var2 ) {
233 entry2 = openVars.find( var2->get_name() );
234 } // if
235 bool isopen1 = var1 && ( entry1 != openVars.end() );
236 bool isopen2 = var2 && ( entry2 != openVars.end() );
237
238 if ( isopen1 && isopen2 ) {
239 if ( entry1->second.kind != entry2->second.kind ) {
240 result = false;
241 } else {
242 result = env.bindVarToVar(
243 var1, var2, TypeDecl::Data{ entry1->second, entry2->second }, needAssertions,
244 haveAssertions, openVars, widen, indexer );
245 }
246 } else if ( isopen1 ) {
247 result = env.bindVar( var1, type2, entry1->second, needAssertions, haveAssertions, openVars, widen, indexer );
248 } else if ( isopen2 ) { // TODO: swap widen values in call, since type positions are flipped?
249 result = env.bindVar( var2, type1, entry2->second, needAssertions, haveAssertions, openVars, widen, indexer );
250 } else {
251 PassVisitor<Unify_old> comparator( type2, env, needAssertions, haveAssertions, openVars, widen, indexer );
252 type1->accept( comparator );
253 result = comparator.pass.get_result();
254 } // if
255#ifdef DEBUG
256 std::cerr << "============ unifyExact" << std::endl;
257 std::cerr << "type1 is ";
258 type1->print( std::cerr );
259 std::cerr << std::endl << "type2 is ";
260 type2->print( std::cerr );
261 std::cerr << std::endl << "openVars are ";
262 printOpenVarSet( openVars, std::cerr, 8 );
263 std::cerr << std::endl << "input env is " << std::endl;
264 debugEnv.print( std::cerr, 8 );
265 std::cerr << std::endl << "result env is " << std::endl;
266 env.print( std::cerr, 8 );
267 std::cerr << "result is " << result << std::endl;
268#endif
269 return result;
270 }
271
272 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
273 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
274 }
275
276 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common ) {
277 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
278 type1->get_qualifiers() = Type::Qualifiers();
279 type2->get_qualifiers() = Type::Qualifiers();
280 bool result;
281#ifdef DEBUG
282 std::cerr << "unifyInexact type 1 is ";
283 type1->print( std::cerr );
284 std::cerr << " type 2 is ";
285 type2->print( std::cerr );
286 std::cerr << std::endl;
287#endif
288 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widen, indexer ) ) {
289#ifdef DEBUG
290 std::cerr << "unifyInexact: no exact unification found" << std::endl;
291#endif
292 if ( ( common = commonType( type1, type2, widen.first, widen.second, indexer, env, openVars ) ) ) {
293 common->tq = tq1.unify( tq2 );
294#ifdef DEBUG
295 std::cerr << "unifyInexact: common type is ";
296 common->print( std::cerr );
297 std::cerr << std::endl;
298#endif
299 result = true;
300 } else {
301#ifdef DEBUG
302 std::cerr << "unifyInexact: no common type found" << std::endl;
303#endif
304 result = false;
305 } // if
306 } else {
307 if ( tq1 != tq2 ) {
308 if ( ( tq1 > tq2 || widen.first ) && ( tq2 > tq1 || widen.second ) ) {
309 common = type1->clone();
310 common->tq = tq1.unify( tq2 );
311 result = true;
312 } else {
313 result = false;
314 } // if
315 } else {
316 common = type1->clone();
317 common->tq = tq1.unify( tq2 );
318 result = true;
319 } // if
320 } // if
321 type1->get_qualifiers() = tq1;
322 type2->get_qualifiers() = tq2;
323 return result;
324 }
325
326 Unify_old::Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer )
327 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widen( widen ), indexer( indexer ) {
328 }
329
330 void Unify_old::postvisit( __attribute__((unused)) VoidType *voidType) {
331 result = dynamic_cast< VoidType* >( type2 );
332 }
333
334 void Unify_old::postvisit(BasicType *basicType) {
335 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
336 result = basicType->get_kind() == otherBasic->get_kind();
337 } // if
338 }
339
340 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
341 AssertionSet::iterator i = assertions.find( assert );
342 if ( i != assertions.end() ) {
343 i->second.isUsed = true;
344 } // if
345 }
346
347 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
348 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
349 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
350 markAssertionSet( assertion1, *assert );
351 markAssertionSet( assertion2, *assert );
352 } // for
353 } // for
354 }
355
356 void Unify_old::postvisit(PointerType *pointerType) {
357 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
358 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
359 markAssertions( haveAssertions, needAssertions, pointerType );
360 markAssertions( haveAssertions, needAssertions, otherPointer );
361 } // if
362 }
363
364 void Unify_old::postvisit(ReferenceType *refType) {
365 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
366 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
367 markAssertions( haveAssertions, needAssertions, refType );
368 markAssertions( haveAssertions, needAssertions, otherRef );
369 } // if
370 }
371
372 void Unify_old::postvisit(ArrayType *arrayType) {
373 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
374 // to unify, array types must both be VLA or both not VLA
375 // and must both have a dimension expression or not have a dimension
376 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
377
378 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
379 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
380 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
381 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
382 // see C11 Reference Manual 6.7.6.2.6
383 // two array types with size specifiers that are integer constant expressions are
384 // compatible if both size specifiers have the same constant value
385 if ( ce1 && ce2 ) {
386 Constant * c1 = ce1->get_constant();
387 Constant * c2 = ce2->get_constant();
388
389 if ( c1->get_value() != c2->get_value() ) {
390 // does not unify if the dimension is different
391 return;
392 }
393 }
394 }
395
396 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
397 } // if
398 }
399
400 template< typename Iterator, typename Func >
401 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
402 std::list< Type * > types;
403 for ( ; begin != end; ++begin ) {
404 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
405 flatten( toType( *begin ), back_inserter( types ) );
406 }
407 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
408 }
409
410 template< typename Iterator1, typename Iterator2 >
411 bool unifyTypeList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
412 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
413 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
414 Type * t1 = (*list1Begin)->get_type();
415 Type * t2 = (*list2Begin)->get_type();
416 bool isTtype1 = Tuples::isTtype( t1 );
417 bool isTtype2 = Tuples::isTtype( t2 );
418 // xxx - assumes ttype must be last parameter
419 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
420 if ( isTtype1 && ! isTtype2 ) {
421 // combine all of the things in list2, then unify
422 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
423 } else if ( isTtype2 && ! isTtype1 ) {
424 // combine all of the things in list1, then unify
425 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
426 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
427 return false;
428 } // if
429 } // for
430 // 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
431 if ( list1Begin != list1End ) {
432 // try unifying empty tuple type with ttype
433 Type * t1 = (*list1Begin)->get_type();
434 if ( Tuples::isTtype( t1 ) ) {
435 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
436 } else return false;
437 } else if ( list2Begin != list2End ) {
438 // try unifying empty tuple type with ttype
439 Type * t2 = (*list2Begin)->get_type();
440 if ( Tuples::isTtype( t2 ) ) {
441 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
442 } else return false;
443 } else {
444 return true;
445 } // if
446 }
447
448 /// Finds ttypes and replaces them with their expansion, if known.
449 /// This needs to be done so that satisfying ttype assertions is easier.
450 /// If this isn't done then argument lists can have wildly different
451 /// size and structure, when they should be compatible.
452 struct TtypeExpander_old : public WithShortCircuiting {
453 TypeEnvironment & tenv;
454 TtypeExpander_old( TypeEnvironment & tenv ) : tenv( tenv ) {}
455 void premutate( TypeInstType * ) { visit_children = false; }
456 Type * postmutate( TypeInstType * typeInst ) {
457 if ( const EqvClass *eqvClass = tenv.lookup( typeInst->get_name() ) ) {
458 // expand ttype parameter into its actual type
459 if ( eqvClass->data.kind == TypeDecl::Ttype && eqvClass->type ) {
460 delete typeInst;
461 return eqvClass->type->clone();
462 }
463 }
464 return typeInst;
465 }
466 };
467
468 /// flattens a list of declarations, so that each tuple type has a single declaration.
469 /// makes use of TtypeExpander to ensure ttypes are flat as well.
470 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
471 dst.clear();
472 for ( DeclarationWithType * dcl : src ) {
473 PassVisitor<TtypeExpander_old> expander( env );
474 dcl->acceptMutator( expander );
475 std::list< Type * > types;
476 flatten( dcl->get_type(), back_inserter( types ) );
477 for ( Type * t : types ) {
478 // 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.
479 // 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.
480 t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic);
481
482 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
483 }
484 delete dcl;
485 }
486 }
487
488 void Unify_old::postvisit(FunctionType *functionType) {
489 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
490 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
491 // flatten the parameter lists for both functions so that tuple structure
492 // doesn't affect unification. Must be a clone so that the types don't change.
493 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
494 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
495 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
496 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
497
498 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
499 if (
500 (flatFunc->parameters.size() == flatOther->parameters.size() &&
501 flatFunc->returnVals.size() == flatOther->returnVals.size())
502 || flatFunc->isTtype()
503 || flatOther->isTtype()
504 ) {
505 if ( unifyTypeList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
506 if ( unifyTypeList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->returnVals.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
507
508 // the original types must be used in mark assertions, since pointer comparisons are used
509 markAssertions( haveAssertions, needAssertions, functionType );
510 markAssertions( haveAssertions, needAssertions, otherFunction );
511
512 result = true;
513 } // if
514 } // if
515 } // if
516 } // if
517 }
518
519 template< typename RefType >
520 void Unify_old::handleRefType( RefType *inst, Type *other ) {
521 // check that other type is compatible and named the same
522 RefType *otherStruct = dynamic_cast< RefType* >( other );
523 result = otherStruct && inst->name == otherStruct->name;
524 }
525
526 template< typename RefType >
527 void Unify_old::handleGenericRefType( RefType *inst, Type *other ) {
528 // Check that other type is compatible and named the same
529 handleRefType( inst, other );
530 if ( ! result ) return;
531 // Check that parameters of types unify, if any
532 std::list< Expression* > params = inst->parameters;
533 std::list< Expression* > otherParams = ((RefType*)other)->parameters;
534
535 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
536 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
537 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
538 assertf(param, "Aggregate parameters should be type expressions");
539 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
540 assertf(otherParam, "Aggregate parameters should be type expressions");
541
542 Type* paramTy = param->get_type();
543 Type* otherParamTy = otherParam->get_type();
544
545 bool tupleParam = Tuples::isTtype( paramTy );
546 bool otherTupleParam = Tuples::isTtype( otherParamTy );
547
548 if ( tupleParam && otherTupleParam ) {
549 ++it; ++jt; // skip ttype parameters for break
550 } else if ( tupleParam ) {
551 // bundle other parameters into tuple to match
552 std::list< Type * > binderTypes;
553
554 do {
555 binderTypes.push_back( otherParam->get_type()->clone() );
556 ++jt;
557
558 if ( jt == otherParams.end() ) break;
559
560 otherParam = dynamic_cast< TypeExpr* >(*jt);
561 assertf(otherParam, "Aggregate parameters should be type expressions");
562 } while (true);
563
564 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
565 ++it; // skip ttype parameter for break
566 } else if ( otherTupleParam ) {
567 // bundle parameters into tuple to match other
568 std::list< Type * > binderTypes;
569
570 do {
571 binderTypes.push_back( param->get_type()->clone() );
572 ++it;
573
574 if ( it == params.end() ) break;
575
576 param = dynamic_cast< TypeExpr* >(*it);
577 assertf(param, "Aggregate parameters should be type expressions");
578 } while (true);
579
580 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
581 ++jt; // skip ttype parameter for break
582 }
583
584 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
585 result = false;
586 return;
587 }
588
589 // ttype parameter should be last
590 if ( tupleParam || otherTupleParam ) break;
591 }
592 result = ( it == params.end() && jt == otherParams.end() );
593 }
594
595 void Unify_old::postvisit(StructInstType *structInst) {
596 handleGenericRefType( structInst, type2 );
597 }
598
599 void Unify_old::postvisit(UnionInstType *unionInst) {
600 handleGenericRefType( unionInst, type2 );
601 }
602
603 void Unify_old::postvisit(EnumInstType *enumInst) {
604 handleRefType( enumInst, type2 );
605 }
606
607 void Unify_old::postvisit(TraitInstType *contextInst) {
608 handleRefType( contextInst, type2 );
609 }
610
611 void Unify_old::postvisit(TypeInstType *typeInst) {
612 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
613 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
614 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
615 result = true;
616/// } else {
617/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
618/// if ( nt ) {
619/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
620/// assert( type );
621/// if ( type->get_base() ) {
622/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
623/// }
624/// }
625 } // if
626 }
627
628 template< typename Iterator1, typename Iterator2 >
629 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
630 auto get_type = [](Type * t) { return t; };
631 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
632 Type * t1 = *list1Begin;
633 Type * t2 = *list2Begin;
634 bool isTtype1 = Tuples::isTtype( t1 );
635 bool isTtype2 = Tuples::isTtype( t2 );
636 // xxx - assumes ttype must be last parameter
637 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
638 if ( isTtype1 && ! isTtype2 ) {
639 // combine all of the things in list2, then unify
640 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
641 } else if ( isTtype2 && ! isTtype1 ) {
642 // combine all of the things in list1, then unify
643 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
644 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
645 return false;
646 } // if
647
648 } // for
649 if ( list1Begin != list1End ) {
650 // try unifying empty tuple type with ttype
651 Type * t1 = *list1Begin;
652 if ( Tuples::isTtype( t1 ) ) {
653 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
654 } else return false;
655 } else if ( list2Begin != list2End ) {
656 // try unifying empty tuple type with ttype
657 Type * t2 = *list2Begin;
658 if ( Tuples::isTtype( t2 ) ) {
659 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
660 } else return false;
661 } else {
662 return true;
663 } // if
664 }
665
666 void Unify_old::postvisit(TupleType *tupleType) {
667 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
668 std::unique_ptr<TupleType> flat1( tupleType->clone() );
669 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
670 std::list<Type *> types1, types2;
671
672 PassVisitor<TtypeExpander_old> expander( env );
673 flat1->acceptMutator( expander );
674 flat2->acceptMutator( expander );
675
676 flatten( flat1.get(), back_inserter( types1 ) );
677 flatten( flat2.get(), back_inserter( types2 ) );
678
679 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
680 } // if
681 }
682
683 void Unify_old::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) {
684 result = dynamic_cast< VarArgsType* >( type2 );
685 }
686
687 void Unify_old::postvisit( __attribute__((unused)) ZeroType *zeroType ) {
688 result = dynamic_cast< ZeroType* >( type2 );
689 }
690
691 void Unify_old::postvisit( __attribute__((unused)) OneType *oneType ) {
692 result = dynamic_cast< OneType* >( type2 );
693 }
694
695 Type * extractResultType( FunctionType * function ) {
696 if ( function->get_returnVals().size() == 0 ) {
697 return new VoidType( Type::Qualifiers() );
698 } else if ( function->get_returnVals().size() == 1 ) {
699 return function->get_returnVals().front()->get_type()->clone();
700 } else {
701 std::list< Type * > types;
702 for ( DeclarationWithType * decl : function->get_returnVals() ) {
703 types.push_back( decl->get_type()->clone() );
704 } // for
705 return new TupleType( Type::Qualifiers(), types );
706 }
707 }
708
709 namespace {
710 /// Replaces ttype variables with their bound types.
711 /// If this isn't done when satifying ttype assertions, then argument lists can have
712 /// different size and structure when they should be compatible.
713 struct TtypeExpander_new : public ast::WithShortCircuiting, public ast::PureVisitor {
714 ast::TypeEnvironment & tenv;
715
716 TtypeExpander_new( ast::TypeEnvironment & env ) : tenv( env ) {}
717
718 const ast::Type * postvisit( const ast::TypeInstType * typeInst ) {
719 if ( const ast::EqvClass * clz = tenv.lookup( *typeInst ) ) {
720 // expand ttype parameter into its actual type
721 if ( clz->data.kind == ast::TypeDecl::Ttype && clz->bound ) {
722 return clz->bound;
723 }
724 }
725 return typeInst;
726 }
727 };
728 }
729
730 std::vector< ast::ptr< ast::Type > > flattenList(
731 const std::vector< ast::ptr< ast::Type > > & src, ast::TypeEnvironment & env
732 ) {
733 std::vector< ast::ptr< ast::Type > > dst;
734 dst.reserve( src.size() );
735 for ( const auto & d : src ) {
736 ast::Pass<TtypeExpander_new> expander{ env };
737 // TtypeExpander pass is impure (may mutate nodes in place)
738 // need to make nodes shared to prevent accidental mutation
739 ast::ptr<ast::Type> dc = d->accept(expander);
740 auto types = flatten( dc );
741 for ( ast::ptr< ast::Type > & t : types ) {
742 // outermost const, volatile, _Atomic qualifiers in parameters should not play
743 // a role in the unification of function types, since they do not determine
744 // whether a function is callable.
745 // NOTE: **must** consider at least mutex qualifier, since functions can be
746 // overloaded on outermost mutex and a mutex function has different
747 // requirements than a non-mutex function
748 remove_qualifiers( t, ast::CV::Const | ast::CV::Volatile | ast::CV::Atomic );
749 dst.emplace_back( t );
750 }
751 }
752 return dst;
753 }
754
755 class Unify_new final : public ast::WithShortCircuiting {
756 const ast::Type * type2;
757 ast::TypeEnvironment & tenv;
758 ast::AssertionSet & need;
759 ast::AssertionSet & have;
760 const ast::OpenVarSet & open;
761 WidenMode widen;
762 const ast::SymbolTable & symtab;
763 public:
764 static size_t traceId;
765 bool result;
766
767 Unify_new(
768 const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need,
769 ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen,
770 const ast::SymbolTable & symtab )
771 : type2(type2), tenv(env), need(need), have(have), open(open), widen(widen),
772 symtab(symtab), result(false) {}
773
774 void previsit( const ast::Node * ) { visit_children = false; }
775
776 void postvisit( const ast::VoidType * ) {
777 result = dynamic_cast< const ast::VoidType * >( type2 );
778 }
779
780 void postvisit( const ast::BasicType * basic ) {
781 if ( auto basic2 = dynamic_cast< const ast::BasicType * >( type2 ) ) {
782 result = basic->kind == basic2->kind;
783 }
784 }
785
786 void postvisit( const ast::PointerType * pointer ) {
787 if ( auto pointer2 = dynamic_cast< const ast::PointerType * >( type2 ) ) {
788 result = unifyExact(
789 pointer->base, pointer2->base, tenv, need, have, open,
790 noWiden(), symtab );
791 }
792 }
793
794 void postvisit( const ast::ArrayType * array ) {
795 auto array2 = dynamic_cast< const ast::ArrayType * >( type2 );
796 if ( ! array2 ) return;
797
798 // to unify, array types must both be VLA or both not VLA and both must have a
799 // dimension expression or not have a dimension
800 if ( array->isVarLen != array2->isVarLen ) return;
801 if ( ! array->isVarLen && ! array2->isVarLen
802 && array->dimension && array2->dimension ) {
803 auto ce1 = array->dimension.as< ast::ConstantExpr >();
804 auto ce2 = array2->dimension.as< ast::ConstantExpr >();
805
806 // see C11 Reference Manual 6.7.6.2.6
807 // two array types with size specifiers that are integer constant expressions are
808 // compatible if both size specifiers have the same constant value
809 if ( ce1 && ce2 && ce1->intValue() != ce2->intValue() ) return;
810 }
811
812 result = unifyExact(
813 array->base, array2->base, tenv, need, have, open, noWiden(),
814 symtab );
815 }
816
817 void postvisit( const ast::ReferenceType * ref ) {
818 if ( auto ref2 = dynamic_cast< const ast::ReferenceType * >( type2 ) ) {
819 result = unifyExact(
820 ref->base, ref2->base, tenv, need, have, open, noWiden(),
821 symtab );
822 }
823 }
824
825 private:
826
827 template< typename Iter >
828 static bool unifyTypeList(
829 Iter crnt1, Iter end1, Iter crnt2, Iter end2, ast::TypeEnvironment & env,
830 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
831 const ast::SymbolTable & symtab
832 ) {
833 while ( crnt1 != end1 && crnt2 != end2 ) {
834 const ast::Type * t1 = *crnt1;
835 const ast::Type * t2 = *crnt2;
836 bool isTuple1 = Tuples::isTtype( t1 );
837 bool isTuple2 = Tuples::isTtype( t2 );
838
839 // assumes here that ttype *must* be last parameter
840 if ( isTuple1 && ! isTuple2 ) {
841 // combine remainder of list2, then unify
842 return unifyExact(
843 t1, tupleFromTypes( crnt2, end2 ), env, need, have, open,
844 noWiden(), symtab );
845 } else if ( ! isTuple1 && isTuple2 ) {
846 // combine remainder of list1, then unify
847 return unifyExact(
848 tupleFromTypes( crnt1, end1 ), t2, env, need, have, open,
849 noWiden(), symtab );
850 }
851
852 if ( ! unifyExact(
853 t1, t2, env, need, have, open, noWiden(), symtab )
854 ) return false;
855
856 ++crnt1; ++crnt2;
857 }
858
859 // May get to the end of one argument list before the other. This is only okay if the
860 // other is a ttype
861 if ( crnt1 != end1 ) {
862 // try unifying empty tuple with ttype
863 const ast::Type * t1 = *crnt1;
864 if ( ! Tuples::isTtype( t1 ) ) return false;
865 return unifyExact(
866 t1, tupleFromTypes( crnt2, end2 ), env, need, have, open,
867 noWiden(), symtab );
868 } else if ( crnt2 != end2 ) {
869 // try unifying empty tuple with ttype
870 const ast::Type * t2 = *crnt2;
871 if ( ! Tuples::isTtype( t2 ) ) return false;
872 return unifyExact(
873 tupleFromTypes( crnt1, end1 ), t2, env, need, have, open,
874 noWiden(), symtab );
875 }
876
877 return true;
878 }
879
880 static bool unifyTypeList(
881 const std::vector< ast::ptr< ast::Type > > & list1,
882 const std::vector< ast::ptr< ast::Type > > & list2,
883 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
884 const ast::OpenVarSet & open, const ast::SymbolTable & symtab
885 ) {
886 return unifyTypeList(
887 list1.begin(), list1.end(), list2.begin(), list2.end(), env, need, have, open,
888 symtab );
889 }
890
891 static void markAssertionSet( ast::AssertionSet & assns, const ast::VariableExpr * assn ) {
892 auto i = assns.find( assn );
893 if ( i != assns.end() ) {
894 i->second.isUsed = true;
895 }
896 }
897
898 /// mark all assertions in `type` used in both `assn1` and `assn2`
899 static void markAssertions(
900 ast::AssertionSet & assn1, ast::AssertionSet & assn2,
901 const ast::FunctionType * type
902 ) {
903 for ( auto & assert : type->assertions ) {
904 markAssertionSet( assn1, assert );
905 markAssertionSet( assn2, assert );
906 }
907 }
908
909 public:
910 void postvisit( const ast::FunctionType * func ) {
911 auto func2 = dynamic_cast< const ast::FunctionType * >( type2 );
912 if ( ! func2 ) return;
913
914 if ( func->isVarArgs != func2->isVarArgs ) return;
915
916 // Flatten the parameter lists for both functions so that tuple structure does not
917 // affect unification. Does not actually mutate function parameters.
918 auto params = flattenList( func->params, tenv );
919 auto params2 = flattenList( func2->params, tenv );
920
921 // sizes don't have to match if ttypes are involved; need to be more precise w.r.t.
922 // where the ttype is to prevent errors
923 if (
924 ( params.size() != params2.size() || func->returns.size() != func2->returns.size() )
925 && ! func->isTtype()
926 && ! func2->isTtype()
927 ) return;
928
929 if ( ! unifyTypeList( params, params2, tenv, need, have, open, symtab ) ) return;
930 if ( ! unifyTypeList(
931 func->returns, func2->returns, tenv, need, have, open, symtab ) ) return;
932
933 markAssertions( have, need, func );
934 markAssertions( have, need, func2 );
935
936 result = true;
937 }
938
939 private:
940 // Returns: other, cast as XInstType
941 // Assigns this->result: whether types are compatible (up to generic parameters)
942 template< typename XInstType >
943 const XInstType * handleRefType( const XInstType * inst, const ast::Type * other ) {
944 // check that the other type is compatible and named the same
945 auto otherInst = dynamic_cast< const XInstType * >( other );
946 if (otherInst && inst->name == otherInst->name) this->result = otherInst;
947 return otherInst;
948 }
949
950 /// Creates a tuple type based on a list of TypeExpr
951 template< typename Iter >
952 static const ast::Type * tupleFromExprs(
953 const ast::TypeExpr * param, Iter & crnt, Iter end, ast::CV::Qualifiers qs
954 ) {
955 std::vector< ast::ptr< ast::Type > > types;
956 do {
957 types.emplace_back( param->type );
958
959 ++crnt;
960 if ( crnt == end ) break;
961 param = strict_dynamic_cast< const ast::TypeExpr * >( crnt->get() );
962 } while(true);
963
964 return new ast::TupleType{ std::move(types), qs };
965 }
966
967 template< typename XInstType >
968 void handleGenericRefType( const XInstType * inst, const ast::Type * other ) {
969 // check that other type is compatible and named the same
970 const XInstType * otherInst = handleRefType( inst, other );
971 if ( ! this->result ) return;
972
973 // check that parameters of types unify, if any
974 const std::vector< ast::ptr< ast::Expr > > & params = inst->params;
975 const std::vector< ast::ptr< ast::Expr > > & params2 = otherInst->params;
976
977 auto it = params.begin();
978 auto jt = params2.begin();
979 for ( ; it != params.end() && jt != params2.end(); ++it, ++jt ) {
980 auto param = strict_dynamic_cast< const ast::TypeExpr * >( it->get() );
981 auto param2 = strict_dynamic_cast< const ast::TypeExpr * >( jt->get() );
982
983 ast::ptr< ast::Type > pty = param->type;
984 ast::ptr< ast::Type > pty2 = param2->type;
985
986 bool isTuple = Tuples::isTtype( pty );
987 bool isTuple2 = Tuples::isTtype( pty2 );
988
989 if ( isTuple && isTuple2 ) {
990 ++it; ++jt; // skip ttype parameters before break
991 } else if ( isTuple ) {
992 // bundle remaining params into tuple
993 pty2 = tupleFromExprs( param2, jt, params2.end(), pty->qualifiers );
994 ++it; // skip ttype parameter for break
995 } else if ( isTuple2 ) {
996 // bundle remaining params into tuple
997 pty = tupleFromExprs( param, it, params.end(), pty2->qualifiers );
998 ++jt; // skip ttype parameter for break
999 }
1000
1001 if ( ! unifyExact(
1002 pty, pty2, tenv, need, have, open, noWiden(), symtab ) ) {
1003 result = false;
1004 return;
1005 }
1006
1007 // ttype parameter should be last
1008 if ( isTuple || isTuple2 ) break;
1009 }
1010 result = it == params.end() && jt == params2.end();
1011 }
1012
1013 public:
1014 void postvisit( const ast::StructInstType * aggrType ) {
1015 handleGenericRefType( aggrType, type2 );
1016 }
1017
1018 void postvisit( const ast::UnionInstType * aggrType ) {
1019 handleGenericRefType( aggrType, type2 );
1020 }
1021
1022 void postvisit( const ast::EnumInstType * aggrType ) {
1023 handleRefType( aggrType, type2 );
1024 }
1025
1026 void postvisit( const ast::TraitInstType * aggrType ) {
1027 handleRefType( aggrType, type2 );
1028 }
1029
1030 void postvisit( const ast::TypeInstType * typeInst ) {
1031 assert( open.find( *typeInst ) == open.end() );
1032 handleRefType( typeInst, type2 );
1033 }
1034
1035 private:
1036 /// Creates a tuple type based on a list of Type
1037
1038 static bool unifyList(
1039 const std::vector< ast::ptr< ast::Type > > & list1,
1040 const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env,
1041 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1042 const ast::SymbolTable & symtab
1043 ) {
1044 auto crnt1 = list1.begin();
1045 auto crnt2 = list2.begin();
1046 while ( crnt1 != list1.end() && crnt2 != list2.end() ) {
1047 const ast::Type * t1 = *crnt1;
1048 const ast::Type * t2 = *crnt2;
1049 bool isTuple1 = Tuples::isTtype( t1 );
1050 bool isTuple2 = Tuples::isTtype( t2 );
1051
1052 // assumes ttype must be last parameter
1053 if ( isTuple1 && ! isTuple2 ) {
1054 // combine entirety of list2, then unify
1055 return unifyExact(
1056 t1, tupleFromTypes( list2 ), env, need, have, open,
1057 noWiden(), symtab );
1058 } else if ( ! isTuple1 && isTuple2 ) {
1059 // combine entirety of list1, then unify
1060 return unifyExact(
1061 tupleFromTypes( list1 ), t2, env, need, have, open,
1062 noWiden(), symtab );
1063 }
1064
1065 if ( ! unifyExact(
1066 t1, t2, env, need, have, open, noWiden(), symtab )
1067 ) return false;
1068
1069 ++crnt1; ++crnt2;
1070 }
1071
1072 if ( crnt1 != list1.end() ) {
1073 // try unifying empty tuple type with ttype
1074 const ast::Type * t1 = *crnt1;
1075 if ( ! Tuples::isTtype( t1 ) ) return false;
1076 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1077 // from Rob's code
1078 return unifyExact(
1079 t1, tupleFromTypes( list2 ), env, need, have, open,
1080 noWiden(), symtab );
1081 } else if ( crnt2 != list2.end() ) {
1082 // try unifying empty tuple with ttype
1083 const ast::Type * t2 = *crnt2;
1084 if ( ! Tuples::isTtype( t2 ) ) return false;
1085 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1086 // from Rob's code
1087 return unifyExact(
1088 tupleFromTypes( list1 ), t2, env, need, have, open,
1089 noWiden(), symtab );
1090 }
1091
1092 return true;
1093 }
1094
1095 public:
1096 void postvisit( const ast::TupleType * tuple ) {
1097 auto tuple2 = dynamic_cast< const ast::TupleType * >( type2 );
1098 if ( ! tuple2 ) return;
1099
1100 ast::Pass<TtypeExpander_new> expander{ tenv };
1101
1102 const ast::Type * flat = tuple->accept( expander );
1103 const ast::Type * flat2 = tuple2->accept( expander );
1104
1105 auto types = flatten( flat );
1106 auto types2 = flatten( flat2 );
1107
1108 result = unifyList( types, types2, tenv, need, have, open, symtab );
1109 }
1110
1111 void postvisit( const ast::VarArgsType * ) {
1112 result = dynamic_cast< const ast::VarArgsType * >( type2 );
1113 }
1114
1115 void postvisit( const ast::ZeroType * ) {
1116 result = dynamic_cast< const ast::ZeroType * >( type2 );
1117 }
1118
1119 void postvisit( const ast::OneType * ) {
1120 result = dynamic_cast< const ast::OneType * >( type2 );
1121 }
1122
1123 private:
1124 template< typename RefType > void handleRefType( RefType *inst, Type *other );
1125 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
1126 };
1127
1128 // size_t Unify_new::traceId = Stats::Heap::new_stacktrace_id("Unify_new");
1129 bool unify(
1130 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1131 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1132 ast::OpenVarSet & open, const ast::SymbolTable & symtab
1133 ) {
1134 ast::ptr<ast::Type> common;
1135 return unify( type1, type2, env, need, have, open, symtab, common );
1136 }
1137
1138 bool unify(
1139 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1140 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1141 ast::OpenVarSet & open, const ast::SymbolTable & symtab, ast::ptr<ast::Type> & common
1142 ) {
1143 ast::OpenVarSet closed;
1144 findOpenVars( type1, open, closed, need, have, FirstClosed );
1145 findOpenVars( type2, open, closed, need, have, FirstOpen );
1146 return unifyInexact(
1147 type1, type2, env, need, have, open, WidenMode{ true, true }, symtab, common );
1148 }
1149
1150 bool unifyExact(
1151 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
1152 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1153 WidenMode widen, const ast::SymbolTable & symtab
1154 ) {
1155 if ( type1->qualifiers != type2->qualifiers ) return false;
1156
1157 auto var1 = dynamic_cast< const ast::TypeInstType * >( type1 );
1158 auto var2 = dynamic_cast< const ast::TypeInstType * >( type2 );
1159 ast::OpenVarSet::const_iterator
1160 entry1 = var1 ? open.find( *var1 ) : open.end(),
1161 entry2 = var2 ? open.find( *var2 ) : open.end();
1162 bool isopen1 = entry1 != open.end();
1163 bool isopen2 = entry2 != open.end();
1164
1165 if ( isopen1 && isopen2 ) {
1166 if ( entry1->second.kind != entry2->second.kind ) return false;
1167 return env.bindVarToVar(
1168 var1, var2, ast::TypeDecl::Data{ entry1->second, entry2->second }, need, have,
1169 open, widen, symtab );
1170 } else if ( isopen1 ) {
1171 return env.bindVar( var1, type2, entry1->second, need, have, open, widen, symtab );
1172 } else if ( isopen2 ) {
1173 return env.bindVar( var2, type1, entry2->second, need, have, open, widen, symtab );
1174 } else {
1175 return ast::Pass<Unify_new>::read(
1176 type1, type2, env, need, have, open, widen, symtab );
1177 }
1178 }
1179
1180 bool unifyInexact(
1181 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1182 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1183 const ast::OpenVarSet & open, WidenMode widen, const ast::SymbolTable & symtab,
1184 ast::ptr<ast::Type> & common
1185 ) {
1186 ast::CV::Qualifiers q1 = type1->qualifiers, q2 = type2->qualifiers;
1187
1188 // force t1 and t2 to be cloned if their qualifiers must be stripped, so that type1 and
1189 // type2 are left unchanged; calling convention forces type{1,2}->strong_ref >= 1
1190 ast::Type * t1 = shallowCopy(type1.get());
1191 ast::Type * t2 = shallowCopy(type2.get());
1192 t1->qualifiers = {};
1193 t2->qualifiers = {};
1194 ast::ptr< ast::Type > t1_(t1);
1195 ast::ptr< ast::Type > t2_(t2);
1196
1197 if ( unifyExact( t1, t2, env, need, have, open, widen, symtab ) ) {
1198 // if exact unification on unqualified types, try to merge qualifiers
1199 if ( q1 == q2 || ( ( q1 > q2 || widen.first ) && ( q2 > q1 || widen.second ) ) ) {
1200 t1->qualifiers = q1 | q2;
1201 common = t1;
1202 return true;
1203 } else {
1204 return false;
1205 }
1206
1207 } else if (( common = commonType( t1, t2, env, need, have, open, widen, symtab ))) {
1208 // no exact unification, but common type
1209 auto c = shallowCopy(common.get());
1210 c->qualifiers = q1 | q2;
1211 common = c;
1212 return true;
1213 } else {
1214 return false;
1215 }
1216 }
1217
1218 ast::ptr<ast::Type> extractResultType( const ast::FunctionType * func ) {
1219 if ( func->returns.empty() ) return new ast::VoidType{};
1220 if ( func->returns.size() == 1 ) return func->returns[0];
1221
1222 std::vector<ast::ptr<ast::Type>> tys;
1223 for ( const auto & decl : func->returns ) {
1224 tys.emplace_back( decl );
1225 }
1226 return new ast::TupleType{ std::move(tys) };
1227 }
1228} // namespace ResolvExpr
1229
1230// Local Variables: //
1231// tab-width: 4 //
1232// mode: c++ //
1233// compile-command: "make install" //
1234// End: //
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