source: src/ResolvExpr/Unify.cc@ 3f3bfe5a

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 3f3bfe5a was 90ce35aa, checked in by Michael Brooks <mlbrooks@…>, 6 years ago

Fixing new-resolver bug where libcfa build erroneously complains about ambiguous ?{} lookup.
  • 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 : Andrew Beach
12// Last Modified On : Wed Sep 4 10:00:00 2019
13// Update Count : 44
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 "Parser/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 return unifyExact(
173 env.apply( newFirst ).node,
174 env.apply( newSecond ).node,
175 newEnv, need, have, open, noWiden(), symtab );
176 }
177
178 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
179 OpenVarSet closedVars;
180 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
181 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
182 Type *commonType = 0;
183 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
184 if ( commonType ) {
185 delete commonType;
186 } // if
187 return true;
188 } else {
189 return false;
190 } // if
191 }
192
193 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
194 OpenVarSet closedVars;
195 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
196 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
197 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
198 }
199
200 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
201#ifdef DEBUG
202 TypeEnvironment debugEnv( env );
203#endif
204 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
205 return false;
206 }
207
208 bool result;
209 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
210 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
211 OpenVarSet::const_iterator entry1, entry2;
212 if ( var1 ) {
213 entry1 = openVars.find( var1->get_name() );
214 } // if
215 if ( var2 ) {
216 entry2 = openVars.find( var2->get_name() );
217 } // if
218 bool isopen1 = var1 && ( entry1 != openVars.end() );
219 bool isopen2 = var2 && ( entry2 != openVars.end() );
220
221 if ( isopen1 && isopen2 ) {
222 if ( entry1->second.kind != entry2->second.kind ) {
223 result = false;
224 } else {
225 result = env.bindVarToVar(
226 var1, var2, TypeDecl::Data{ entry1->second, entry2->second }, needAssertions,
227 haveAssertions, openVars, widen, indexer );
228 }
229 } else if ( isopen1 ) {
230 result = env.bindVar( var1, type2, entry1->second, needAssertions, haveAssertions, openVars, widen, indexer );
231 } else if ( isopen2 ) { // TODO: swap widen values in call, since type positions are flipped?
232 result = env.bindVar( var2, type1, entry2->second, needAssertions, haveAssertions, openVars, widen, indexer );
233 } else {
234 PassVisitor<Unify_old> comparator( type2, env, needAssertions, haveAssertions, openVars, widen, indexer );
235 type1->accept( comparator );
236 result = comparator.pass.get_result();
237 } // if
238#ifdef DEBUG
239 std::cerr << "============ unifyExact" << std::endl;
240 std::cerr << "type1 is ";
241 type1->print( std::cerr );
242 std::cerr << std::endl << "type2 is ";
243 type2->print( std::cerr );
244 std::cerr << std::endl << "openVars are ";
245 printOpenVarSet( openVars, std::cerr, 8 );
246 std::cerr << std::endl << "input env is " << std::endl;
247 debugEnv.print( std::cerr, 8 );
248 std::cerr << std::endl << "result env is " << std::endl;
249 env.print( std::cerr, 8 );
250 std::cerr << "result is " << result << std::endl;
251#endif
252 return result;
253 }
254
255 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
256 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
257 }
258
259 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common ) {
260 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
261 type1->get_qualifiers() = Type::Qualifiers();
262 type2->get_qualifiers() = Type::Qualifiers();
263 bool result;
264#ifdef DEBUG
265 std::cerr << "unifyInexact type 1 is ";
266 type1->print( std::cerr );
267 std::cerr << " type 2 is ";
268 type2->print( std::cerr );
269 std::cerr << std::endl;
270#endif
271 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widen, indexer ) ) {
272#ifdef DEBUG
273 std::cerr << "unifyInexact: no exact unification found" << std::endl;
274#endif
275 if ( ( common = commonType( type1, type2, widen.first, widen.second, indexer, env, openVars ) ) ) {
276 common->tq = tq1.unify( tq2 );
277#ifdef DEBUG
278 std::cerr << "unifyInexact: common type is ";
279 common->print( std::cerr );
280 std::cerr << std::endl;
281#endif
282 result = true;
283 } else {
284#ifdef DEBUG
285 std::cerr << "unifyInexact: no common type found" << std::endl;
286#endif
287 result = false;
288 } // if
289 } else {
290 if ( tq1 != tq2 ) {
291 if ( ( tq1 > tq2 || widen.first ) && ( tq2 > tq1 || widen.second ) ) {
292 common = type1->clone();
293 common->tq = tq1.unify( tq2 );
294 result = true;
295 } else {
296 result = false;
297 } // if
298 } else {
299 common = type1->clone();
300 common->tq = tq1.unify( tq2 );
301 result = true;
302 } // if
303 } // if
304 type1->get_qualifiers() = tq1;
305 type2->get_qualifiers() = tq2;
306 return result;
307 }
308
309 Unify_old::Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer )
310 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widen( widen ), indexer( indexer ) {
311 }
312
313 void Unify_old::postvisit( __attribute__((unused)) VoidType *voidType) {
314 result = dynamic_cast< VoidType* >( type2 );
315 }
316
317 void Unify_old::postvisit(BasicType *basicType) {
318 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
319 result = basicType->get_kind() == otherBasic->get_kind();
320 } // if
321 }
322
323 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
324 AssertionSet::iterator i = assertions.find( assert );
325 if ( i != assertions.end() ) {
326 i->second.isUsed = true;
327 } // if
328 }
329
330 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
331 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
332 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
333 markAssertionSet( assertion1, *assert );
334 markAssertionSet( assertion2, *assert );
335 } // for
336 } // for
337 }
338
339 void Unify_old::postvisit(PointerType *pointerType) {
340 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
341 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
342 markAssertions( haveAssertions, needAssertions, pointerType );
343 markAssertions( haveAssertions, needAssertions, otherPointer );
344 } // if
345 }
346
347 void Unify_old::postvisit(ReferenceType *refType) {
348 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
349 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
350 markAssertions( haveAssertions, needAssertions, refType );
351 markAssertions( haveAssertions, needAssertions, otherRef );
352 } // if
353 }
354
355 void Unify_old::postvisit(ArrayType *arrayType) {
356 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
357 // to unify, array types must both be VLA or both not VLA
358 // and must both have a dimension expression or not have a dimension
359 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
360
361 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
362 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
363 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
364 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
365 // see C11 Reference Manual 6.7.6.2.6
366 // two array types with size specifiers that are integer constant expressions are
367 // compatible if both size specifiers have the same constant value
368 if ( ce1 && ce2 ) {
369 Constant * c1 = ce1->get_constant();
370 Constant * c2 = ce2->get_constant();
371
372 if ( c1->get_value() != c2->get_value() ) {
373 // does not unify if the dimension is different
374 return;
375 }
376 }
377 }
378
379 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
380 } // if
381 }
382
383 template< typename Iterator, typename Func >
384 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
385 std::list< Type * > types;
386 for ( ; begin != end; ++begin ) {
387 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
388 flatten( toType( *begin ), back_inserter( types ) );
389 }
390 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
391 }
392
393 template< typename Iterator1, typename Iterator2 >
394 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
395 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
396 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
397 Type * t1 = (*list1Begin)->get_type();
398 Type * t2 = (*list2Begin)->get_type();
399 bool isTtype1 = Tuples::isTtype( t1 );
400 bool isTtype2 = Tuples::isTtype( t2 );
401 // xxx - assumes ttype must be last parameter
402 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
403 if ( isTtype1 && ! isTtype2 ) {
404 // combine all of the things in list2, then unify
405 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
406 } else if ( isTtype2 && ! isTtype1 ) {
407 // combine all of the things in list1, then unify
408 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
409 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
410 return false;
411 } // if
412 } // for
413 // 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
414 if ( list1Begin != list1End ) {
415 // try unifying empty tuple type with ttype
416 Type * t1 = (*list1Begin)->get_type();
417 if ( Tuples::isTtype( t1 ) ) {
418 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
419 } else return false;
420 } else if ( list2Begin != list2End ) {
421 // try unifying empty tuple type with ttype
422 Type * t2 = (*list2Begin)->get_type();
423 if ( Tuples::isTtype( t2 ) ) {
424 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
425 } else return false;
426 } else {
427 return true;
428 } // if
429 }
430
431 /// Finds ttypes and replaces them with their expansion, if known.
432 /// This needs to be done so that satisfying ttype assertions is easier.
433 /// If this isn't done then argument lists can have wildly different
434 /// size and structure, when they should be compatible.
435 struct TtypeExpander_old : public WithShortCircuiting {
436 TypeEnvironment & tenv;
437 TtypeExpander_old( TypeEnvironment & tenv ) : tenv( tenv ) {}
438 void premutate( TypeInstType * ) { visit_children = false; }
439 Type * postmutate( TypeInstType * typeInst ) {
440 if ( const EqvClass *eqvClass = tenv.lookup( typeInst->get_name() ) ) {
441 // expand ttype parameter into its actual type
442 if ( eqvClass->data.kind == TypeDecl::Ttype && eqvClass->type ) {
443 delete typeInst;
444 return eqvClass->type->clone();
445 }
446 }
447 return typeInst;
448 }
449 };
450
451 /// flattens a list of declarations, so that each tuple type has a single declaration.
452 /// makes use of TtypeExpander to ensure ttypes are flat as well.
453 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
454 dst.clear();
455 for ( DeclarationWithType * dcl : src ) {
456 PassVisitor<TtypeExpander_old> expander( env );
457 dcl->acceptMutator( expander );
458 std::list< Type * > types;
459 flatten( dcl->get_type(), back_inserter( types ) );
460 for ( Type * t : types ) {
461 // 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.
462 // 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.
463 t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic);
464
465 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
466 }
467 delete dcl;
468 }
469 }
470
471 void Unify_old::postvisit(FunctionType *functionType) {
472 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
473 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
474 // flatten the parameter lists for both functions so that tuple structure
475 // doesn't affect unification. Must be a clone so that the types don't change.
476 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
477 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
478 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
479 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
480
481 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
482 if (
483 (flatFunc->parameters.size() == flatOther->parameters.size() &&
484 flatFunc->returnVals.size() == flatOther->returnVals.size())
485 || flatFunc->isTtype()
486 || flatOther->isTtype()
487 ) {
488 if ( unifyDeclList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
489 if ( unifyDeclList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->returnVals.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
490
491 // the original types must be used in mark assertions, since pointer comparisons are used
492 markAssertions( haveAssertions, needAssertions, functionType );
493 markAssertions( haveAssertions, needAssertions, otherFunction );
494
495 result = true;
496 } // if
497 } // if
498 } // if
499 } // if
500 }
501
502 template< typename RefType >
503 void Unify_old::handleRefType( RefType *inst, Type *other ) {
504 // check that other type is compatible and named the same
505 RefType *otherStruct = dynamic_cast< RefType* >( other );
506 result = otherStruct && inst->name == otherStruct->name;
507 }
508
509 template< typename RefType >
510 void Unify_old::handleGenericRefType( RefType *inst, Type *other ) {
511 // Check that other type is compatible and named the same
512 handleRefType( inst, other );
513 if ( ! result ) return;
514 // Check that parameters of types unify, if any
515 std::list< Expression* > params = inst->parameters;
516 std::list< Expression* > otherParams = ((RefType*)other)->parameters;
517
518 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
519 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
520 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
521 assertf(param, "Aggregate parameters should be type expressions");
522 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
523 assertf(otherParam, "Aggregate parameters should be type expressions");
524
525 Type* paramTy = param->get_type();
526 Type* otherParamTy = otherParam->get_type();
527
528 bool tupleParam = Tuples::isTtype( paramTy );
529 bool otherTupleParam = Tuples::isTtype( otherParamTy );
530
531 if ( tupleParam && otherTupleParam ) {
532 ++it; ++jt; // skip ttype parameters for break
533 } else if ( tupleParam ) {
534 // bundle other parameters into tuple to match
535 std::list< Type * > binderTypes;
536
537 do {
538 binderTypes.push_back( otherParam->get_type()->clone() );
539 ++jt;
540
541 if ( jt == otherParams.end() ) break;
542
543 otherParam = dynamic_cast< TypeExpr* >(*jt);
544 assertf(otherParam, "Aggregate parameters should be type expressions");
545 } while (true);
546
547 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
548 ++it; // skip ttype parameter for break
549 } else if ( otherTupleParam ) {
550 // bundle parameters into tuple to match other
551 std::list< Type * > binderTypes;
552
553 do {
554 binderTypes.push_back( param->get_type()->clone() );
555 ++it;
556
557 if ( it == params.end() ) break;
558
559 param = dynamic_cast< TypeExpr* >(*it);
560 assertf(param, "Aggregate parameters should be type expressions");
561 } while (true);
562
563 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
564 ++jt; // skip ttype parameter for break
565 }
566
567 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
568 result = false;
569 return;
570 }
571
572 // ttype parameter should be last
573 if ( tupleParam || otherTupleParam ) break;
574 }
575 result = ( it == params.end() && jt == otherParams.end() );
576 }
577
578 void Unify_old::postvisit(StructInstType *structInst) {
579 handleGenericRefType( structInst, type2 );
580 }
581
582 void Unify_old::postvisit(UnionInstType *unionInst) {
583 handleGenericRefType( unionInst, type2 );
584 }
585
586 void Unify_old::postvisit(EnumInstType *enumInst) {
587 handleRefType( enumInst, type2 );
588 }
589
590 void Unify_old::postvisit(TraitInstType *contextInst) {
591 handleRefType( contextInst, type2 );
592 }
593
594 void Unify_old::postvisit(TypeInstType *typeInst) {
595 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
596 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
597 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
598 result = true;
599/// } else {
600/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
601/// if ( nt ) {
602/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
603/// assert( type );
604/// if ( type->get_base() ) {
605/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
606/// }
607/// }
608 } // if
609 }
610
611 template< typename Iterator1, typename Iterator2 >
612 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
613 auto get_type = [](Type * t) { return t; };
614 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
615 Type * t1 = *list1Begin;
616 Type * t2 = *list2Begin;
617 bool isTtype1 = Tuples::isTtype( t1 );
618 bool isTtype2 = Tuples::isTtype( t2 );
619 // xxx - assumes ttype must be last parameter
620 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
621 if ( isTtype1 && ! isTtype2 ) {
622 // combine all of the things in list2, then unify
623 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
624 } else if ( isTtype2 && ! isTtype1 ) {
625 // combine all of the things in list1, then unify
626 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
627 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
628 return false;
629 } // if
630
631 } // for
632 if ( list1Begin != list1End ) {
633 // try unifying empty tuple type with ttype
634 Type * t1 = *list1Begin;
635 if ( Tuples::isTtype( t1 ) ) {
636 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
637 } else return false;
638 } else if ( list2Begin != list2End ) {
639 // try unifying empty tuple type with ttype
640 Type * t2 = *list2Begin;
641 if ( Tuples::isTtype( t2 ) ) {
642 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
643 } else return false;
644 } else {
645 return true;
646 } // if
647 }
648
649 void Unify_old::postvisit(TupleType *tupleType) {
650 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
651 std::unique_ptr<TupleType> flat1( tupleType->clone() );
652 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
653 std::list<Type *> types1, types2;
654
655 PassVisitor<TtypeExpander_old> expander( env );
656 flat1->acceptMutator( expander );
657 flat2->acceptMutator( expander );
658
659 flatten( flat1.get(), back_inserter( types1 ) );
660 flatten( flat2.get(), back_inserter( types2 ) );
661
662 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
663 } // if
664 }
665
666 void Unify_old::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) {
667 result = dynamic_cast< VarArgsType* >( type2 );
668 }
669
670 void Unify_old::postvisit( __attribute__((unused)) ZeroType *zeroType ) {
671 result = dynamic_cast< ZeroType* >( type2 );
672 }
673
674 void Unify_old::postvisit( __attribute__((unused)) OneType *oneType ) {
675 result = dynamic_cast< OneType* >( type2 );
676 }
677
678 Type * extractResultType( FunctionType * function ) {
679 if ( function->get_returnVals().size() == 0 ) {
680 return new VoidType( Type::Qualifiers() );
681 } else if ( function->get_returnVals().size() == 1 ) {
682 return function->get_returnVals().front()->get_type()->clone();
683 } else {
684 std::list< Type * > types;
685 for ( DeclarationWithType * decl : function->get_returnVals() ) {
686 types.push_back( decl->get_type()->clone() );
687 } // for
688 return new TupleType( Type::Qualifiers(), types );
689 }
690 }
691
692 class Unify_new final : public ast::WithShortCircuiting {
693 const ast::Type * type2;
694 ast::TypeEnvironment & tenv;
695 ast::AssertionSet & need;
696 ast::AssertionSet & have;
697 const ast::OpenVarSet & open;
698 WidenMode widen;
699 const ast::SymbolTable & symtab;
700 public:
701 bool result;
702
703 Unify_new(
704 const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need,
705 ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen,
706 const ast::SymbolTable & symtab )
707 : type2(type2), tenv(env), need(need), have(have), open(open), widen(widen),
708 symtab(symtab), result(false) {}
709
710 void previsit( const ast::Node * ) { visit_children = false; }
711
712 void postvisit( const ast::VoidType * ) {
713 result = dynamic_cast< const ast::VoidType * >( type2 );
714 }
715
716 void postvisit( const ast::BasicType * basic ) {
717 if ( auto basic2 = dynamic_cast< const ast::BasicType * >( type2 ) ) {
718 result = basic->kind == basic2->kind;
719 }
720 }
721
722 void postvisit( const ast::PointerType * pointer ) {
723 if ( auto pointer2 = dynamic_cast< const ast::PointerType * >( type2 ) ) {
724 result = unifyExact(
725 pointer->base, pointer2->base, tenv, need, have, open,
726 noWiden(), symtab );
727 }
728 }
729
730 void postvisit( const ast::ArrayType * array ) {
731 auto array2 = dynamic_cast< const ast::ArrayType * >( type2 );
732 if ( ! array2 ) return;
733
734 // to unify, array types must both be VLA or both not VLA and both must have a
735 // dimension expression or not have a dimension
736 if ( array->isVarLen != array2->isVarLen ) return;
737 if ( ! array->isVarLen && ! array2->isVarLen
738 && array->dimension && array2->dimension ) {
739 auto ce1 = array->dimension.as< ast::ConstantExpr >();
740 auto ce2 = array2->dimension.as< ast::ConstantExpr >();
741
742 // see C11 Reference Manual 6.7.6.2.6
743 // two array types with size specifiers that are integer constant expressions are
744 // compatible if both size specifiers have the same constant value
745 if ( ce1 && ce2 && ce1->intValue() != ce2->intValue() ) return;
746 }
747
748 result = unifyExact(
749 array->base, array2->base, tenv, need, have, open, noWiden(),
750 symtab );
751 }
752
753 void postvisit( const ast::ReferenceType * ref ) {
754 if ( auto ref2 = dynamic_cast< const ast::ReferenceType * >( type2 ) ) {
755 result = unifyExact(
756 ref->base, ref2->base, tenv, need, have, open, noWiden(),
757 symtab );
758 }
759 }
760
761 private:
762 /// Replaces ttype variables with their bound types.
763 /// If this isn't done when satifying ttype assertions, then argument lists can have
764 /// different size and structure when they should be compatible.
765 struct TtypeExpander_new : public ast::WithShortCircuiting {
766 ast::TypeEnvironment & tenv;
767
768 TtypeExpander_new( ast::TypeEnvironment & env ) : tenv( env ) {}
769
770 const ast::Type * postvisit( const ast::TypeInstType * typeInst ) {
771 if ( const ast::EqvClass * clz = tenv.lookup( typeInst->name ) ) {
772 // expand ttype parameter into its actual type
773 if ( clz->data.kind == ast::TypeVar::Ttype && clz->bound ) {
774 return clz->bound;
775 }
776 }
777 return typeInst;
778 }
779 };
780
781 /// returns flattened version of `src`
782 static std::vector< ast::ptr< ast::DeclWithType > > flattenList(
783 const std::vector< ast::ptr< ast::DeclWithType > > & src, ast::TypeEnvironment & env
784 ) {
785 std::vector< ast::ptr< ast::DeclWithType > > dst;
786 dst.reserve( src.size() );
787 for ( const ast::DeclWithType * d : src ) {
788 ast::Pass<TtypeExpander_new> expander{ env };
789 d = d->accept( expander );
790 auto types = flatten( d->get_type() );
791 for ( ast::ptr< ast::Type > & t : types ) {
792 // outermost const, volatile, _Atomic qualifiers in parameters should not play
793 // a role in the unification of function types, since they do not determine
794 // whether a function is callable.
795 // NOTE: **must** consider at least mutex qualifier, since functions can be
796 // overloaded on outermost mutex and a mutex function has different
797 // requirements than a non-mutex function
798 remove_qualifiers( t, ast::CV::Const | ast::CV::Volatile | ast::CV::Atomic );
799 dst.emplace_back( new ast::ObjectDecl{ d->location, "", t } );
800 }
801 }
802 return dst;
803 }
804
805 /// Creates a tuple type based on a list of DeclWithType
806 template< typename Iter >
807 static ast::ptr< ast::Type > tupleFromDecls( Iter crnt, Iter end ) {
808 std::vector< ast::ptr< ast::Type > > types;
809 while ( crnt != end ) {
810 // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure
811 // that this results in a flat tuple
812 flatten( (*crnt)->get_type(), types );
813
814 ++crnt;
815 }
816
817 return { new ast::TupleType{ std::move(types) } };
818 }
819
820 template< typename Iter >
821 static bool unifyDeclList(
822 Iter crnt1, Iter end1, Iter crnt2, Iter end2, ast::TypeEnvironment & env,
823 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
824 const ast::SymbolTable & symtab
825 ) {
826 while ( crnt1 != end1 && crnt2 != end2 ) {
827 const ast::Type * t1 = (*crnt1)->get_type();
828 const ast::Type * t2 = (*crnt2)->get_type();
829 bool isTuple1 = Tuples::isTtype( t1 );
830 bool isTuple2 = Tuples::isTtype( t2 );
831
832 // assumes here that ttype *must* be last parameter
833 if ( isTuple1 && ! isTuple2 ) {
834 // combine remainder of list2, then unify
835 return unifyExact(
836 t1, tupleFromDecls( crnt2, end2 ), env, need, have, open,
837 noWiden(), symtab );
838 } else if ( ! isTuple1 && isTuple2 ) {
839 // combine remainder of list1, then unify
840 return unifyExact(
841 tupleFromDecls( crnt1, end1 ), t2, env, need, have, open,
842 noWiden(), symtab );
843 }
844
845 if ( ! unifyExact(
846 t1, t2, env, need, have, open, noWiden(), symtab )
847 ) return false;
848
849 ++crnt1; ++crnt2;
850 }
851
852 // May get to the end of one argument list before the other. This is only okay if the
853 // other is a ttype
854 if ( crnt1 != end1 ) {
855 // try unifying empty tuple with ttype
856 const ast::Type * t1 = (*crnt1)->get_type();
857 if ( ! Tuples::isTtype( t1 ) ) return false;
858 return unifyExact(
859 t1, tupleFromDecls( crnt2, end2 ), env, need, have, open,
860 noWiden(), symtab );
861 } else if ( crnt2 != end2 ) {
862 // try unifying empty tuple with ttype
863 const ast::Type * t2 = (*crnt2)->get_type();
864 if ( ! Tuples::isTtype( t2 ) ) return false;
865 return unifyExact(
866 tupleFromDecls( crnt1, end1 ), t2, env, need, have, open,
867 noWiden(), symtab );
868 }
869
870 return true;
871 }
872
873 static bool unifyDeclList(
874 const std::vector< ast::ptr< ast::DeclWithType > > & list1,
875 const std::vector< ast::ptr< ast::DeclWithType > > & list2,
876 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
877 const ast::OpenVarSet & open, const ast::SymbolTable & symtab
878 ) {
879 return unifyDeclList(
880 list1.begin(), list1.end(), list2.begin(), list2.end(), env, need, have, open,
881 symtab );
882 }
883
884 static void markAssertionSet( ast::AssertionSet & assns, const ast::DeclWithType * assn ) {
885 auto i = assns.find( assn );
886 if ( i != assns.end() ) {
887 i->second.isUsed = true;
888 }
889 }
890
891 /// mark all assertions in `type` used in both `assn1` and `assn2`
892 static void markAssertions(
893 ast::AssertionSet & assn1, ast::AssertionSet & assn2,
894 const ast::ParameterizedType * type
895 ) {
896 for ( const auto & tyvar : type->forall ) {
897 for ( const ast::DeclWithType * assert : tyvar->assertions ) {
898 markAssertionSet( assn1, assert );
899 markAssertionSet( assn2, assert );
900 }
901 }
902 }
903
904 public:
905 void postvisit( const ast::FunctionType * func ) {
906 auto func2 = dynamic_cast< const ast::FunctionType * >( type2 );
907 if ( ! func2 ) return;
908
909 if ( func->isVarArgs != func2->isVarArgs ) return;
910
911 // Flatten the parameter lists for both functions so that tuple structure does not
912 // affect unification. Does not actually mutate function parameters.
913 auto params = flattenList( func->params, tenv );
914 auto params2 = flattenList( func2->params, tenv );
915
916 // sizes don't have to match if ttypes are involved; need to be more precise w.r.t.
917 // where the ttype is to prevent errors
918 if (
919 ( params.size() != params2.size() || func->returns.size() != func2->returns.size() )
920 && ! func->isTtype()
921 && ! func2->isTtype()
922 ) return;
923
924 if ( ! unifyDeclList( params, params2, tenv, need, have, open, symtab ) ) return;
925 if ( ! unifyDeclList(
926 func->returns, func2->returns, tenv, need, have, open, symtab ) ) return;
927
928 markAssertions( have, need, func );
929 markAssertions( have, need, func2 );
930
931 result = true;
932 }
933
934 private:
935 // Returns: other, cast as XInstType
936 // Assigns this->result: whether types are compatible (up to generic parameters)
937 template< typename XInstType >
938 const XInstType * handleRefType( const XInstType * inst, const ast::Type * other ) {
939 // check that the other type is compatible and named the same
940 auto otherInst = dynamic_cast< const XInstType * >( other );
941 this->result = otherInst && inst->name == otherInst->name;
942 return otherInst;
943 }
944
945 /// Creates a tuple type based on a list of TypeExpr
946 template< typename Iter >
947 static const ast::Type * tupleFromExprs(
948 const ast::TypeExpr * param, Iter & crnt, Iter end, ast::CV::Qualifiers qs
949 ) {
950 std::vector< ast::ptr< ast::Type > > types;
951 do {
952 types.emplace_back( param->type );
953
954 ++crnt;
955 if ( crnt == end ) break;
956 param = strict_dynamic_cast< const ast::TypeExpr * >( crnt->get() );
957 } while(true);
958
959 return new ast::TupleType{ std::move(types), qs };
960 }
961
962 template< typename XInstType >
963 void handleGenericRefType( const XInstType * inst, const ast::Type * other ) {
964 // check that other type is compatible and named the same
965 const XInstType * otherInst = handleRefType( inst, other );
966 if ( ! this->result ) return;
967
968 // check that parameters of types unify, if any
969 const std::vector< ast::ptr< ast::Expr > > & params = inst->params;
970 const std::vector< ast::ptr< ast::Expr > > & params2 = otherInst->params;
971
972 auto it = params.begin();
973 auto jt = params2.begin();
974 for ( ; it != params.end() && jt != params2.end(); ++it, ++jt ) {
975 auto param = strict_dynamic_cast< const ast::TypeExpr * >( it->get() );
976 auto param2 = strict_dynamic_cast< const ast::TypeExpr * >( jt->get() );
977
978 ast::ptr< ast::Type > pty = param->type;
979 ast::ptr< ast::Type > pty2 = param2->type;
980
981 bool isTuple = Tuples::isTtype( pty );
982 bool isTuple2 = Tuples::isTtype( pty2 );
983
984 if ( isTuple && isTuple2 ) {
985 ++it; ++jt; // skip ttype parameters before break
986 } else if ( isTuple ) {
987 // bundle remaining params into tuple
988 pty2 = tupleFromExprs( param2, jt, params2.end(), pty->qualifiers );
989 ++it; // skip ttype parameter for break
990 } else if ( isTuple2 ) {
991 // bundle remaining params into tuple
992 pty = tupleFromExprs( param, it, params.end(), pty2->qualifiers );
993 ++jt; // skip ttype parameter for break
994 }
995
996 if ( ! unifyExact(
997 pty, pty2, tenv, need, have, open, noWiden(), symtab ) ) {
998 result = false;
999 return;
1000 }
1001
1002 // ttype parameter should be last
1003 if ( isTuple || isTuple2 ) break;
1004 }
1005 result = it == params.end() && jt == params2.end();
1006 }
1007
1008 public:
1009 void postvisit( const ast::StructInstType * aggrType ) {
1010 handleGenericRefType( aggrType, type2 );
1011 }
1012
1013 void postvisit( const ast::UnionInstType * aggrType ) {
1014 handleGenericRefType( aggrType, type2 );
1015 }
1016
1017 void postvisit( const ast::EnumInstType * aggrType ) {
1018 handleRefType( aggrType, type2 );
1019 }
1020
1021 void postvisit( const ast::TraitInstType * aggrType ) {
1022 handleRefType( aggrType, type2 );
1023 }
1024
1025 void postvisit( const ast::TypeInstType * typeInst ) {
1026 assert( open.find( typeInst->name ) == open.end() );
1027 handleRefType( typeInst, type2 );
1028 }
1029
1030 private:
1031 /// Creates a tuple type based on a list of Type
1032 static ast::ptr< ast::Type > tupleFromTypes(
1033 const std::vector< ast::ptr< ast::Type > > & tys
1034 ) {
1035 std::vector< ast::ptr< ast::Type > > out;
1036 for ( const ast::Type * ty : tys ) {
1037 // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure
1038 // that this results in a flat tuple
1039 flatten( ty, out );
1040 }
1041
1042 return { new ast::TupleType{ std::move(out) } };
1043 }
1044
1045 static bool unifyList(
1046 const std::vector< ast::ptr< ast::Type > > & list1,
1047 const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env,
1048 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1049 const ast::SymbolTable & symtab
1050 ) {
1051 auto crnt1 = list1.begin();
1052 auto crnt2 = list2.begin();
1053 while ( crnt1 != list1.end() && crnt2 != list2.end() ) {
1054 const ast::Type * t1 = *crnt1;
1055 const ast::Type * t2 = *crnt2;
1056 bool isTuple1 = Tuples::isTtype( t1 );
1057 bool isTuple2 = Tuples::isTtype( t2 );
1058
1059 // assumes ttype must be last parameter
1060 if ( isTuple1 && ! isTuple2 ) {
1061 // combine entirety of list2, then unify
1062 return unifyExact(
1063 t1, tupleFromTypes( list2 ), env, need, have, open,
1064 noWiden(), symtab );
1065 } else if ( ! isTuple1 && isTuple2 ) {
1066 // combine entirety of list1, then unify
1067 return unifyExact(
1068 tupleFromTypes( list1 ), t2, env, need, have, open,
1069 noWiden(), symtab );
1070 }
1071
1072 if ( ! unifyExact(
1073 t1, t2, env, need, have, open, noWiden(), symtab )
1074 ) return false;
1075
1076 ++crnt1; ++crnt2;
1077 }
1078
1079 if ( crnt1 != list1.end() ) {
1080 // try unifying empty tuple type with ttype
1081 const ast::Type * t1 = *crnt1;
1082 if ( ! Tuples::isTtype( t1 ) ) return false;
1083 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1084 // from Rob's code
1085 return unifyExact(
1086 t1, tupleFromTypes( list2 ), env, need, have, open,
1087 noWiden(), symtab );
1088 } else if ( crnt2 != list2.end() ) {
1089 // try unifying empty tuple with ttype
1090 const ast::Type * t2 = *crnt2;
1091 if ( ! Tuples::isTtype( t2 ) ) return false;
1092 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1093 // from Rob's code
1094 return unifyExact(
1095 tupleFromTypes( list1 ), t2, env, need, have, open,
1096 noWiden(), symtab );
1097 }
1098
1099 return true;
1100 }
1101
1102 public:
1103 void postvisit( const ast::TupleType * tuple ) {
1104 auto tuple2 = dynamic_cast< const ast::TupleType * >( type2 );
1105 if ( ! tuple2 ) return;
1106
1107 ast::Pass<TtypeExpander_new> expander{ tenv };
1108 const ast::Type * flat = tuple->accept( expander );
1109 const ast::Type * flat2 = tuple2->accept( expander );
1110
1111 auto types = flatten( flat );
1112 auto types2 = flatten( flat2 );
1113
1114 result = unifyList( types, types2, tenv, need, have, open, symtab );
1115 }
1116
1117 void postvisit( const ast::VarArgsType * ) {
1118 result = dynamic_cast< const ast::VarArgsType * >( type2 );
1119 }
1120
1121 void postvisit( const ast::ZeroType * ) {
1122 result = dynamic_cast< const ast::ZeroType * >( type2 );
1123 }
1124
1125 void postvisit( const ast::OneType * ) {
1126 result = dynamic_cast< const ast::OneType * >( type2 );
1127 }
1128
1129 private:
1130 template< typename RefType > void handleRefType( RefType *inst, Type *other );
1131 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
1132 };
1133
1134 bool unify(
1135 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1136 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1137 ast::OpenVarSet & open, const ast::SymbolTable & symtab
1138 ) {
1139 ast::ptr<ast::Type> common;
1140 return unify( type1, type2, env, need, have, open, symtab, common );
1141 }
1142
1143 bool unify(
1144 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1145 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1146 ast::OpenVarSet & open, const ast::SymbolTable & symtab, ast::ptr<ast::Type> & common
1147 ) {
1148 ast::OpenVarSet closed;
1149 findOpenVars( type1, open, closed, need, have, FirstClosed );
1150 findOpenVars( type2, open, closed, need, have, FirstOpen );
1151 return unifyInexact(
1152 type1, type2, env, need, have, open, WidenMode{ true, true }, symtab, common );
1153 }
1154
1155 bool unifyExact(
1156 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
1157 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1158 WidenMode widen, const ast::SymbolTable & symtab
1159 ) {
1160 if ( type1->qualifiers != type2->qualifiers ) return false;
1161
1162 auto var1 = dynamic_cast< const ast::TypeInstType * >( type1 );
1163 auto var2 = dynamic_cast< const ast::TypeInstType * >( type2 );
1164 ast::OpenVarSet::const_iterator
1165 entry1 = var1 ? open.find( var1->name ) : open.end(),
1166 entry2 = var2 ? open.find( var2->name ) : open.end();
1167 bool isopen1 = entry1 != open.end();
1168 bool isopen2 = entry2 != open.end();
1169
1170 if ( isopen1 && isopen2 ) {
1171 if ( entry1->second.kind != entry2->second.kind ) return false;
1172 return env.bindVarToVar(
1173 var1, var2, ast::TypeDecl::Data{ entry1->second, entry2->second }, need, have,
1174 open, widen, symtab );
1175 } else if ( isopen1 ) {
1176 return env.bindVar( var1, type2, entry1->second, need, have, open, widen, symtab );
1177 } else if ( isopen2 ) {
1178 return env.bindVar( var2, type1, entry2->second, need, have, open, widen, symtab );
1179 } else {
1180 ast::Pass<Unify_new> comparator{ type2, env, need, have, open, widen, symtab };
1181 type1->accept( comparator );
1182 return comparator.pass.result;
1183 }
1184 }
1185
1186 bool unifyInexact(
1187 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1188 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1189 const ast::OpenVarSet & open, WidenMode widen, const ast::SymbolTable & symtab,
1190 ast::ptr<ast::Type> & common
1191 ) {
1192 ast::CV::Qualifiers q1 = type1->qualifiers, q2 = type2->qualifiers;
1193
1194 // force t1 and t2 to be cloned if their qualifiers must be stripped, so that type1 and
1195 // type2 are left unchanged; calling convention forces type{1,2}->strong_ref >= 1
1196 ast::Type * t1 = shallowCopy(type1.get());
1197 ast::Type * t2 = shallowCopy(type2.get());
1198 t1->qualifiers = {};
1199 t2->qualifiers = {};
1200 ast::ptr< ast::Type > t1_(t1);
1201 ast::ptr< ast::Type > t2_(t2);
1202
1203 if ( unifyExact( t1, t2, env, need, have, open, widen, symtab ) ) {
1204 // if exact unification on unqualified types, try to merge qualifiers
1205 if ( q1 == q2 || ( ( q1 > q2 || widen.first ) && ( q2 > q1 || widen.second ) ) ) {
1206 t1->qualifiers = q1 | q2;
1207 common = t1;
1208 return true;
1209 } else {
1210 return false;
1211 }
1212
1213 } else if (( common = commonType( t1, t2, widen, symtab, env, open ) )) {
1214 // no exact unification, but common type
1215 auto c = shallowCopy(common.get());
1216 c->qualifiers = q1 | q2;
1217 common = c;
1218 return true;
1219 } else {
1220 return false;
1221 }
1222 }
1223
1224 ast::ptr<ast::Type> extractResultType( const ast::FunctionType * func ) {
1225 if ( func->returns.empty() ) return new ast::VoidType{};
1226 if ( func->returns.size() == 1 ) return func->returns[0]->get_type();
1227
1228 std::vector<ast::ptr<ast::Type>> tys;
1229 for ( const ast::DeclWithType * decl : func->returns ) {
1230 tys.emplace_back( decl->get_type() );
1231 }
1232 return new ast::TupleType{ std::move(tys) };
1233 }
1234} // namespace ResolvExpr
1235
1236// Local Variables: //
1237// tab-width: 4 //
1238// mode: c++ //
1239// compile-command: "make install" //
1240// End: //
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