source: src/ResolvExpr/Unify.cc@ fed6a0f

ADT ast-experimental
Last change on this file since fed6a0f was e563edf, checked in by Andrew Beach <ajbeach@…>, 3 years ago

Header Clean-up: Clearing out typeops, moving things to Unify because that header already exist.
  • Property mode set to 100644
File size: 48.9 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 {
52 class Indexer;
53} // namespace SymTab
54
55// #define DEBUG
56
57namespace ResolvExpr {
58
59// Template Helpers:
60template< typename Iterator1, typename Iterator2 >
61bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, std::list< Type* > &commonTypes ) {
62 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
63 Type *commonType = 0;
64 if ( ! unify( *list1Begin, *list2Begin, env, needAssertions, haveAssertions, openVars, indexer, commonType ) ) {
65 return false;
66 } // if
67 commonTypes.push_back( commonType );
68 } // for
69 return ( list1Begin == list1End && list2Begin == list2End );
70}
71
72template< typename Iterator1, typename Iterator2 >
73bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
74 std::list< Type* > commonTypes;
75 if ( unifyList( list1Begin, list1End, list2Begin, list2End, env, needAssertions, haveAssertions, openVars, indexer, commonTypes ) ) {
76 deleteAll( commonTypes );
77 return true;
78 } else {
79 return false;
80 } // if
81}
82
83 struct Unify_old : public WithShortCircuiting {
84 Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
85
86 bool get_result() const { return result; }
87
88 void previsit( BaseSyntaxNode * ) { visit_children = false; }
89
90 void postvisit( VoidType * voidType );
91 void postvisit( BasicType * basicType );
92 void postvisit( PointerType * pointerType );
93 void postvisit( ArrayType * arrayType );
94 void postvisit( ReferenceType * refType );
95 void postvisit( FunctionType * functionType );
96 void postvisit( StructInstType * aggregateUseType );
97 void postvisit( UnionInstType * aggregateUseType );
98 void postvisit( EnumInstType * aggregateUseType );
99 void postvisit( TraitInstType * aggregateUseType );
100 void postvisit( TypeInstType * aggregateUseType );
101 void postvisit( TupleType * tupleType );
102 void postvisit( VarArgsType * varArgsType );
103 void postvisit( ZeroType * zeroType );
104 void postvisit( OneType * oneType );
105
106 private:
107 template< typename RefType > void handleRefType( RefType *inst, Type *other );
108 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
109
110 bool result;
111 Type *type2; // inherited
112 TypeEnvironment &env;
113 AssertionSet &needAssertions;
114 AssertionSet &haveAssertions;
115 const OpenVarSet &openVars;
116 WidenMode widen;
117 const SymTab::Indexer &indexer;
118 };
119
120 /// Attempts an inexact unification of type1 and type2.
121 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
122 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common );
123 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
124
125 bool unifyExact(
126 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
127 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
128 WidenMode widen, const ast::SymbolTable & symtab );
129
130 bool typesCompatible( const Type * first, const Type * second, const SymTab::Indexer & indexer, const TypeEnvironment & env ) {
131 TypeEnvironment newEnv;
132 OpenVarSet openVars, closedVars; // added closedVars
133 AssertionSet needAssertions, haveAssertions;
134 Type * newFirst = first->clone(), * newSecond = second->clone();
135 env.apply( newFirst );
136 env.apply( newSecond );
137
138 // do we need to do this? Seems like we do, types should be able to be compatible if they
139 // have free variables that can unify
140 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
141 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
142
143 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
144 delete newFirst;
145 delete newSecond;
146 return result;
147 }
148
149 bool typesCompatible(
150 const ast::Type * first, const ast::Type * second, const ast::SymbolTable & symtab,
151 const ast::TypeEnvironment & env ) {
152 ast::TypeEnvironment newEnv;
153 ast::OpenVarSet open, closed;
154 ast::AssertionSet need, have;
155
156 ast::ptr<ast::Type> newFirst{ first }, newSecond{ second };
157 env.apply( newFirst );
158 env.apply( newSecond );
159
160 findOpenVars( newFirst, open, closed, need, have, FirstClosed );
161 findOpenVars( newSecond, open, closed, need, have, FirstOpen );
162
163 return unifyExact(newFirst, newSecond, newEnv, need, have, open, noWiden(), symtab );
164 }
165
166 bool typesCompatibleIgnoreQualifiers( const Type * first, const Type * second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
167 TypeEnvironment newEnv;
168 OpenVarSet openVars;
169 AssertionSet needAssertions, haveAssertions;
170 Type *newFirst = first->clone(), *newSecond = second->clone();
171 env.apply( newFirst );
172 env.apply( newSecond );
173 newFirst->get_qualifiers() = Type::Qualifiers();
174 newSecond->get_qualifiers() = Type::Qualifiers();
175
176 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
177 delete newFirst;
178 delete newSecond;
179 return result;
180 }
181
182 bool typesCompatibleIgnoreQualifiers(
183 const ast::Type * first, const ast::Type * second, const ast::SymbolTable & symtab,
184 const ast::TypeEnvironment & env ) {
185 ast::TypeEnvironment newEnv;
186 ast::OpenVarSet open;
187 ast::AssertionSet need, have;
188
189 ast::Type * newFirst = shallowCopy( first );
190 ast::Type * newSecond = shallowCopy( second );
191 if ( auto temp = dynamic_cast<const ast::EnumInstType *>(first) ) {
192 if ( !dynamic_cast< const ast::EnumInstType * >( second ) ) {
193 const ast::EnumDecl * baseEnum = dynamic_cast<const ast::EnumDecl *>(temp->base.get());
194 if ( auto t = baseEnum->base.get() ) {
195 newFirst = ast::shallowCopy( t );
196 }
197 }
198 } else if ( auto temp = dynamic_cast<const ast::EnumInstType *>(second) ) {
199 const ast::EnumDecl * baseEnum = dynamic_cast<const ast::EnumDecl *>(temp->base.get());
200 if ( auto t = baseEnum->base.get() ) {
201 newSecond = ast::shallowCopy( t );
202 }
203 }
204
205 newFirst ->qualifiers = {};
206 newSecond->qualifiers = {};
207 ast::ptr< ast::Type > t1_(newFirst );
208 ast::ptr< ast::Type > t2_(newSecond);
209
210 ast::ptr< ast::Type > subFirst = env.apply(newFirst).node;
211 ast::ptr< ast::Type > subSecond = env.apply(newSecond).node;
212
213 return unifyExact(
214 subFirst,
215 subSecond,
216 newEnv, need, have, open, noWiden(), symtab );
217 }
218
219 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
220 OpenVarSet closedVars;
221 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
222 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
223 Type *commonType = 0;
224 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
225 if ( commonType ) {
226 delete commonType;
227 } // if
228 return true;
229 } else {
230 return false;
231 } // if
232 }
233
234 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
235 OpenVarSet closedVars;
236 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
237 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
238 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
239 }
240
241 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
242#ifdef DEBUG
243 TypeEnvironment debugEnv( env );
244#endif
245 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
246 return false;
247 }
248
249 bool result;
250 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
251 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
252 OpenVarSet::const_iterator entry1, entry2;
253 if ( var1 ) {
254 entry1 = openVars.find( var1->get_name() );
255 } // if
256 if ( var2 ) {
257 entry2 = openVars.find( var2->get_name() );
258 } // if
259 bool isopen1 = var1 && ( entry1 != openVars.end() );
260 bool isopen2 = var2 && ( entry2 != openVars.end() );
261
262 if ( isopen1 && isopen2 ) {
263 if ( entry1->second.kind != entry2->second.kind ) {
264 result = false;
265 } else {
266 result = env.bindVarToVar(
267 var1, var2, TypeDecl::Data{ entry1->second, entry2->second }, needAssertions,
268 haveAssertions, openVars, widen, indexer );
269 }
270 } else if ( isopen1 ) {
271 result = env.bindVar( var1, type2, entry1->second, needAssertions, haveAssertions, openVars, widen, indexer );
272 } else if ( isopen2 ) { // TODO: swap widen values in call, since type positions are flipped?
273 result = env.bindVar( var2, type1, entry2->second, needAssertions, haveAssertions, openVars, widen, indexer );
274 } else {
275 PassVisitor<Unify_old> comparator( type2, env, needAssertions, haveAssertions, openVars, widen, indexer );
276 type1->accept( comparator );
277 result = comparator.pass.get_result();
278 } // if
279#ifdef DEBUG
280 std::cerr << "============ unifyExact" << std::endl;
281 std::cerr << "type1 is ";
282 type1->print( std::cerr );
283 std::cerr << std::endl << "type2 is ";
284 type2->print( std::cerr );
285 std::cerr << std::endl << "openVars are ";
286 printOpenVarSet( openVars, std::cerr, 8 );
287 std::cerr << std::endl << "input env is " << std::endl;
288 debugEnv.print( std::cerr, 8 );
289 std::cerr << std::endl << "result env is " << std::endl;
290 env.print( std::cerr, 8 );
291 std::cerr << "result is " << result << std::endl;
292#endif
293 return result;
294 }
295
296 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
297 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
298 }
299
300 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common ) {
301 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
302 type1->get_qualifiers() = Type::Qualifiers();
303 type2->get_qualifiers() = Type::Qualifiers();
304 bool result;
305#ifdef DEBUG
306 std::cerr << "unifyInexact type 1 is ";
307 type1->print( std::cerr );
308 std::cerr << " type 2 is ";
309 type2->print( std::cerr );
310 std::cerr << std::endl;
311#endif
312 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widen, indexer ) ) {
313#ifdef DEBUG
314 std::cerr << "unifyInexact: no exact unification found" << std::endl;
315#endif
316 if ( ( common = commonType( type1, type2, widen.first, widen.second, indexer, env, openVars ) ) ) {
317 common->tq = tq1.unify( tq2 );
318#ifdef DEBUG
319 std::cerr << "unifyInexact: common type is ";
320 common->print( std::cerr );
321 std::cerr << std::endl;
322#endif
323 result = true;
324 } else {
325#ifdef DEBUG
326 std::cerr << "unifyInexact: no common type found" << std::endl;
327#endif
328 result = false;
329 } // if
330 } else {
331 if ( tq1 != tq2 ) {
332 if ( ( tq1 > tq2 || widen.first ) && ( tq2 > tq1 || widen.second ) ) {
333 common = type1->clone();
334 common->tq = tq1.unify( tq2 );
335 result = true;
336 } else {
337 result = false;
338 } // if
339 } else {
340 common = type1->clone();
341 common->tq = tq1.unify( tq2 );
342 result = true;
343 } // if
344 } // if
345 type1->get_qualifiers() = tq1;
346 type2->get_qualifiers() = tq2;
347 return result;
348 }
349
350 Unify_old::Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer )
351 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widen( widen ), indexer( indexer ) {
352 }
353
354 void Unify_old::postvisit( __attribute__((unused)) VoidType *voidType) {
355 result = dynamic_cast< VoidType* >( type2 );
356 }
357
358 void Unify_old::postvisit(BasicType *basicType) {
359 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
360 result = basicType->get_kind() == otherBasic->get_kind();
361 } // if
362 }
363
364 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
365 AssertionSet::iterator i = assertions.find( assert );
366 if ( i != assertions.end() ) {
367 i->second.isUsed = true;
368 } // if
369 }
370
371 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
372 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
373 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
374 markAssertionSet( assertion1, *assert );
375 markAssertionSet( assertion2, *assert );
376 } // for
377 } // for
378 }
379
380 void Unify_old::postvisit(PointerType *pointerType) {
381 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
382 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
383 markAssertions( haveAssertions, needAssertions, pointerType );
384 markAssertions( haveAssertions, needAssertions, otherPointer );
385 } // if
386 }
387
388 void Unify_old::postvisit(ReferenceType *refType) {
389 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
390 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
391 markAssertions( haveAssertions, needAssertions, refType );
392 markAssertions( haveAssertions, needAssertions, otherRef );
393 } // if
394 }
395
396 void Unify_old::postvisit(ArrayType *arrayType) {
397 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
398 // to unify, array types must both be VLA or both not VLA
399 // and must both have a dimension expression or not have a dimension
400 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
401
402 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
403 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
404 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
405 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
406 // see C11 Reference Manual 6.7.6.2.6
407 // two array types with size specifiers that are integer constant expressions are
408 // compatible if both size specifiers have the same constant value
409 if ( ce1 && ce2 ) {
410 Constant * c1 = ce1->get_constant();
411 Constant * c2 = ce2->get_constant();
412
413 if ( c1->get_value() != c2->get_value() ) {
414 // does not unify if the dimension is different
415 return;
416 }
417 }
418 }
419
420 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
421 } // if
422 }
423
424 template< typename Iterator, typename Func >
425 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
426 std::list< Type * > types;
427 for ( ; begin != end; ++begin ) {
428 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
429 flatten( toType( *begin ), back_inserter( types ) );
430 }
431 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
432 }
433
434 template< typename Iterator1, typename Iterator2 >
435 bool unifyTypeList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
436 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
437 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
438 Type * t1 = (*list1Begin)->get_type();
439 Type * t2 = (*list2Begin)->get_type();
440 bool isTtype1 = Tuples::isTtype( t1 );
441 bool isTtype2 = Tuples::isTtype( t2 );
442 // xxx - assumes ttype must be last parameter
443 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
444 if ( isTtype1 && ! isTtype2 ) {
445 // combine all of the things in list2, then unify
446 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
447 } else if ( isTtype2 && ! isTtype1 ) {
448 // combine all of the things in list1, then unify
449 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
450 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
451 return false;
452 } // if
453 } // for
454 // 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
455 if ( list1Begin != list1End ) {
456 // try unifying empty tuple type with ttype
457 Type * t1 = (*list1Begin)->get_type();
458 if ( Tuples::isTtype( t1 ) ) {
459 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
460 } else return false;
461 } else if ( list2Begin != list2End ) {
462 // try unifying empty tuple type with ttype
463 Type * t2 = (*list2Begin)->get_type();
464 if ( Tuples::isTtype( t2 ) ) {
465 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
466 } else return false;
467 } else {
468 return true;
469 } // if
470 }
471
472 /// Finds ttypes and replaces them with their expansion, if known.
473 /// This needs to be done so that satisfying ttype assertions is easier.
474 /// If this isn't done then argument lists can have wildly different
475 /// size and structure, when they should be compatible.
476 struct TtypeExpander_old : public WithShortCircuiting {
477 TypeEnvironment & tenv;
478 TtypeExpander_old( TypeEnvironment & tenv ) : tenv( tenv ) {}
479 void premutate( TypeInstType * ) { visit_children = false; }
480 Type * postmutate( TypeInstType * typeInst ) {
481 if ( const EqvClass *eqvClass = tenv.lookup( typeInst->get_name() ) ) {
482 // expand ttype parameter into its actual type
483 if ( eqvClass->data.kind == TypeDecl::Ttype && eqvClass->type ) {
484 delete typeInst;
485 return eqvClass->type->clone();
486 }
487 }
488 return typeInst;
489 }
490 };
491
492 /// flattens a list of declarations, so that each tuple type has a single declaration.
493 /// makes use of TtypeExpander to ensure ttypes are flat as well.
494 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
495 dst.clear();
496 for ( DeclarationWithType * dcl : src ) {
497 PassVisitor<TtypeExpander_old> expander( env );
498 dcl->acceptMutator( expander );
499 std::list< Type * > types;
500 flatten( dcl->get_type(), back_inserter( types ) );
501 for ( Type * t : types ) {
502 // 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.
503 // 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.
504 t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic);
505
506 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
507 }
508 delete dcl;
509 }
510 }
511
512 void Unify_old::postvisit(FunctionType *functionType) {
513 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
514 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
515 // flatten the parameter lists for both functions so that tuple structure
516 // doesn't affect unification. Must be a clone so that the types don't change.
517 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
518 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
519 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
520 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
521
522 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
523 if (
524 (flatFunc->parameters.size() == flatOther->parameters.size() &&
525 flatFunc->returnVals.size() == flatOther->returnVals.size())
526 || flatFunc->isTtype()
527 || flatOther->isTtype()
528 ) {
529 if ( unifyTypeList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
530 if ( unifyTypeList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->returnVals.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
531
532 // the original types must be used in mark assertions, since pointer comparisons are used
533 markAssertions( haveAssertions, needAssertions, functionType );
534 markAssertions( haveAssertions, needAssertions, otherFunction );
535
536 result = true;
537 } // if
538 } // if
539 } // if
540 } // if
541 }
542
543 template< typename RefType >
544 void Unify_old::handleRefType( RefType *inst, Type *other ) {
545 // check that other type is compatible and named the same
546 RefType *otherStruct = dynamic_cast< RefType* >( other );
547 result = otherStruct && inst->name == otherStruct->name;
548 }
549
550 template< typename RefType >
551 void Unify_old::handleGenericRefType( RefType *inst, Type *other ) {
552 // Check that other type is compatible and named the same
553 handleRefType( inst, other );
554 if ( ! result ) return;
555 // Check that parameters of types unify, if any
556 std::list< Expression* > params = inst->parameters;
557 std::list< Expression* > otherParams = ((RefType*)other)->parameters;
558
559 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
560 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
561 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
562 assertf(param, "Aggregate parameters should be type expressions");
563 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
564 assertf(otherParam, "Aggregate parameters should be type expressions");
565
566 Type* paramTy = param->get_type();
567 Type* otherParamTy = otherParam->get_type();
568
569 bool tupleParam = Tuples::isTtype( paramTy );
570 bool otherTupleParam = Tuples::isTtype( otherParamTy );
571
572 if ( tupleParam && otherTupleParam ) {
573 ++it; ++jt; // skip ttype parameters for break
574 } else if ( tupleParam ) {
575 // bundle other parameters into tuple to match
576 std::list< Type * > binderTypes;
577
578 do {
579 binderTypes.push_back( otherParam->get_type()->clone() );
580 ++jt;
581
582 if ( jt == otherParams.end() ) break;
583
584 otherParam = dynamic_cast< TypeExpr* >(*jt);
585 assertf(otherParam, "Aggregate parameters should be type expressions");
586 } while (true);
587
588 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
589 ++it; // skip ttype parameter for break
590 } else if ( otherTupleParam ) {
591 // bundle parameters into tuple to match other
592 std::list< Type * > binderTypes;
593
594 do {
595 binderTypes.push_back( param->get_type()->clone() );
596 ++it;
597
598 if ( it == params.end() ) break;
599
600 param = dynamic_cast< TypeExpr* >(*it);
601 assertf(param, "Aggregate parameters should be type expressions");
602 } while (true);
603
604 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
605 ++jt; // skip ttype parameter for break
606 }
607
608 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
609 result = false;
610 return;
611 }
612
613 // ttype parameter should be last
614 if ( tupleParam || otherTupleParam ) break;
615 }
616 result = ( it == params.end() && jt == otherParams.end() );
617 }
618
619 void Unify_old::postvisit(StructInstType *structInst) {
620 handleGenericRefType( structInst, type2 );
621 }
622
623 void Unify_old::postvisit(UnionInstType *unionInst) {
624 handleGenericRefType( unionInst, type2 );
625 }
626
627 void Unify_old::postvisit(EnumInstType *enumInst) {
628 handleRefType( enumInst, type2 );
629 }
630
631 void Unify_old::postvisit(TraitInstType *contextInst) {
632 handleRefType( contextInst, type2 );
633 }
634
635 void Unify_old::postvisit(TypeInstType *typeInst) {
636 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
637 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
638 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
639 result = true;
640/// } else {
641/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
642/// if ( nt ) {
643/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
644/// assert( type );
645/// if ( type->get_base() ) {
646/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
647/// }
648/// }
649 } // if
650 }
651
652 template< typename Iterator1, typename Iterator2 >
653 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
654 auto get_type = [](Type * t) { return t; };
655 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
656 Type * t1 = *list1Begin;
657 Type * t2 = *list2Begin;
658 bool isTtype1 = Tuples::isTtype( t1 );
659 bool isTtype2 = Tuples::isTtype( t2 );
660 // xxx - assumes ttype must be last parameter
661 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
662 if ( isTtype1 && ! isTtype2 ) {
663 // combine all of the things in list2, then unify
664 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
665 } else if ( isTtype2 && ! isTtype1 ) {
666 // combine all of the things in list1, then unify
667 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
668 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
669 return false;
670 } // if
671
672 } // for
673 if ( list1Begin != list1End ) {
674 // try unifying empty tuple type with ttype
675 Type * t1 = *list1Begin;
676 if ( Tuples::isTtype( t1 ) ) {
677 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
678 } else return false;
679 } else if ( list2Begin != list2End ) {
680 // try unifying empty tuple type with ttype
681 Type * t2 = *list2Begin;
682 if ( Tuples::isTtype( t2 ) ) {
683 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
684 } else return false;
685 } else {
686 return true;
687 } // if
688 }
689
690 void Unify_old::postvisit(TupleType *tupleType) {
691 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
692 std::unique_ptr<TupleType> flat1( tupleType->clone() );
693 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
694 std::list<Type *> types1, types2;
695
696 PassVisitor<TtypeExpander_old> expander( env );
697 flat1->acceptMutator( expander );
698 flat2->acceptMutator( expander );
699
700 flatten( flat1.get(), back_inserter( types1 ) );
701 flatten( flat2.get(), back_inserter( types2 ) );
702
703 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
704 } // if
705 }
706
707 void Unify_old::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) {
708 result = dynamic_cast< VarArgsType* >( type2 );
709 }
710
711 void Unify_old::postvisit( __attribute__((unused)) ZeroType *zeroType ) {
712 result = dynamic_cast< ZeroType* >( type2 );
713 }
714
715 void Unify_old::postvisit( __attribute__((unused)) OneType *oneType ) {
716 result = dynamic_cast< OneType* >( type2 );
717 }
718
719 Type * extractResultType( FunctionType * function ) {
720 if ( function->get_returnVals().size() == 0 ) {
721 return new VoidType( Type::Qualifiers() );
722 } else if ( function->get_returnVals().size() == 1 ) {
723 return function->get_returnVals().front()->get_type()->clone();
724 } else {
725 std::list< Type * > types;
726 for ( DeclarationWithType * decl : function->get_returnVals() ) {
727 types.push_back( decl->get_type()->clone() );
728 } // for
729 return new TupleType( Type::Qualifiers(), types );
730 }
731 }
732
733 namespace {
734 /// Replaces ttype variables with their bound types.
735 /// If this isn't done when satifying ttype assertions, then argument lists can have
736 /// different size and structure when they should be compatible.
737 struct TtypeExpander_new : public ast::WithShortCircuiting, public ast::PureVisitor {
738 ast::TypeEnvironment & tenv;
739
740 TtypeExpander_new( ast::TypeEnvironment & env ) : tenv( env ) {}
741
742 const ast::Type * postvisit( const ast::TypeInstType * typeInst ) {
743 if ( const ast::EqvClass * clz = tenv.lookup( *typeInst ) ) {
744 // expand ttype parameter into its actual type
745 if ( clz->data.kind == ast::TypeDecl::Ttype && clz->bound ) {
746 return clz->bound;
747 }
748 }
749 return typeInst;
750 }
751 };
752 }
753
754 std::vector< ast::ptr< ast::Type > > flattenList(
755 const std::vector< ast::ptr< ast::Type > > & src, ast::TypeEnvironment & env
756 ) {
757 std::vector< ast::ptr< ast::Type > > dst;
758 dst.reserve( src.size() );
759 for ( const auto & d : src ) {
760 ast::Pass<TtypeExpander_new> expander{ env };
761 // TtypeExpander pass is impure (may mutate nodes in place)
762 // need to make nodes shared to prevent accidental mutation
763 ast::ptr<ast::Type> dc = d->accept(expander);
764 auto types = flatten( dc );
765 for ( ast::ptr< ast::Type > & t : types ) {
766 // outermost const, volatile, _Atomic qualifiers in parameters should not play
767 // a role in the unification of function types, since they do not determine
768 // whether a function is callable.
769 // NOTE: **must** consider at least mutex qualifier, since functions can be
770 // overloaded on outermost mutex and a mutex function has different
771 // requirements than a non-mutex function
772 remove_qualifiers( t, ast::CV::Const | ast::CV::Volatile | ast::CV::Atomic );
773 dst.emplace_back( t );
774 }
775 }
776 return dst;
777 }
778
779 class Unify_new final : public ast::WithShortCircuiting {
780 const ast::Type * type2;
781 ast::TypeEnvironment & tenv;
782 ast::AssertionSet & need;
783 ast::AssertionSet & have;
784 const ast::OpenVarSet & open;
785 WidenMode widen;
786 const ast::SymbolTable & symtab;
787 public:
788 static size_t traceId;
789 bool result;
790
791 Unify_new(
792 const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need,
793 ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen,
794 const ast::SymbolTable & symtab )
795 : type2(type2), tenv(env), need(need), have(have), open(open), widen(widen),
796 symtab(symtab), result(false) {}
797
798 void previsit( const ast::Node * ) { visit_children = false; }
799
800 void postvisit( const ast::VoidType * ) {
801 result = dynamic_cast< const ast::VoidType * >( type2 );
802 }
803
804 void postvisit( const ast::BasicType * basic ) {
805 if ( auto basic2 = dynamic_cast< const ast::BasicType * >( type2 ) ) {
806 result = basic->kind == basic2->kind;
807 }
808 }
809
810 void postvisit( const ast::PointerType * pointer ) {
811 if ( auto pointer2 = dynamic_cast< const ast::PointerType * >( type2 ) ) {
812 result = unifyExact(
813 pointer->base, pointer2->base, tenv, need, have, open,
814 noWiden(), symtab );
815 }
816 }
817
818 void postvisit( const ast::ArrayType * array ) {
819 auto array2 = dynamic_cast< const ast::ArrayType * >( type2 );
820 if ( ! array2 ) return;
821
822 // to unify, array types must both be VLA or both not VLA and both must have a
823 // dimension expression or not have a dimension
824 if ( array->isVarLen != array2->isVarLen ) return;
825 if ( ! array->isVarLen && ! array2->isVarLen
826 && array->dimension && array2->dimension ) {
827 auto ce1 = array->dimension.as< ast::ConstantExpr >();
828 auto ce2 = array2->dimension.as< ast::ConstantExpr >();
829
830 // see C11 Reference Manual 6.7.6.2.6
831 // two array types with size specifiers that are integer constant expressions are
832 // compatible if both size specifiers have the same constant value
833 if ( ce1 && ce2 && ce1->intValue() != ce2->intValue() ) return;
834 }
835
836 result = unifyExact(
837 array->base, array2->base, tenv, need, have, open, noWiden(),
838 symtab );
839 }
840
841 void postvisit( const ast::ReferenceType * ref ) {
842 if ( auto ref2 = dynamic_cast< const ast::ReferenceType * >( type2 ) ) {
843 result = unifyExact(
844 ref->base, ref2->base, tenv, need, have, open, noWiden(),
845 symtab );
846 }
847 }
848
849 private:
850
851 template< typename Iter >
852 static bool unifyTypeList(
853 Iter crnt1, Iter end1, Iter crnt2, Iter end2, ast::TypeEnvironment & env,
854 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
855 const ast::SymbolTable & symtab
856 ) {
857 while ( crnt1 != end1 && crnt2 != end2 ) {
858 const ast::Type * t1 = *crnt1;
859 const ast::Type * t2 = *crnt2;
860 bool isTuple1 = Tuples::isTtype( t1 );
861 bool isTuple2 = Tuples::isTtype( t2 );
862
863 // assumes here that ttype *must* be last parameter
864 if ( isTuple1 && ! isTuple2 ) {
865 // combine remainder of list2, then unify
866 return unifyExact(
867 t1, tupleFromTypes( crnt2, end2 ), env, need, have, open,
868 noWiden(), symtab );
869 } else if ( ! isTuple1 && isTuple2 ) {
870 // combine remainder of list1, then unify
871 return unifyExact(
872 tupleFromTypes( crnt1, end1 ), t2, env, need, have, open,
873 noWiden(), symtab );
874 }
875
876 if ( ! unifyExact(
877 t1, t2, env, need, have, open, noWiden(), symtab )
878 ) return false;
879
880 ++crnt1; ++crnt2;
881 }
882
883 // May get to the end of one argument list before the other. This is only okay if the
884 // other is a ttype
885 if ( crnt1 != end1 ) {
886 // try unifying empty tuple with ttype
887 const ast::Type * t1 = *crnt1;
888 if ( ! Tuples::isTtype( t1 ) ) return false;
889 return unifyExact(
890 t1, tupleFromTypes( crnt2, end2 ), env, need, have, open,
891 noWiden(), symtab );
892 } else if ( crnt2 != end2 ) {
893 // try unifying empty tuple with ttype
894 const ast::Type * t2 = *crnt2;
895 if ( ! Tuples::isTtype( t2 ) ) return false;
896 return unifyExact(
897 tupleFromTypes( crnt1, end1 ), t2, env, need, have, open,
898 noWiden(), symtab );
899 }
900
901 return true;
902 }
903
904 static bool unifyTypeList(
905 const std::vector< ast::ptr< ast::Type > > & list1,
906 const std::vector< ast::ptr< ast::Type > > & list2,
907 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
908 const ast::OpenVarSet & open, const ast::SymbolTable & symtab
909 ) {
910 return unifyTypeList(
911 list1.begin(), list1.end(), list2.begin(), list2.end(), env, need, have, open,
912 symtab );
913 }
914
915 static void markAssertionSet( ast::AssertionSet & assns, const ast::VariableExpr * assn ) {
916 auto i = assns.find( assn );
917 if ( i != assns.end() ) {
918 i->second.isUsed = true;
919 }
920 }
921
922 /// mark all assertions in `type` used in both `assn1` and `assn2`
923 static void markAssertions(
924 ast::AssertionSet & assn1, ast::AssertionSet & assn2,
925 const ast::FunctionType * type
926 ) {
927 for ( auto & assert : type->assertions ) {
928 markAssertionSet( assn1, assert );
929 markAssertionSet( assn2, assert );
930 }
931 }
932
933 public:
934 void postvisit( const ast::FunctionType * func ) {
935 auto func2 = dynamic_cast< const ast::FunctionType * >( type2 );
936 if ( ! func2 ) return;
937
938 if ( func->isVarArgs != func2->isVarArgs ) return;
939
940 // Flatten the parameter lists for both functions so that tuple structure does not
941 // affect unification. Does not actually mutate function parameters.
942 auto params = flattenList( func->params, tenv );
943 auto params2 = flattenList( func2->params, tenv );
944
945 // sizes don't have to match if ttypes are involved; need to be more precise w.r.t.
946 // where the ttype is to prevent errors
947 if (
948 ( params.size() != params2.size() || func->returns.size() != func2->returns.size() )
949 && ! func->isTtype()
950 && ! func2->isTtype()
951 ) return;
952
953 if ( ! unifyTypeList( params, params2, tenv, need, have, open, symtab ) ) return;
954 if ( ! unifyTypeList(
955 func->returns, func2->returns, tenv, need, have, open, symtab ) ) return;
956
957 markAssertions( have, need, func );
958 markAssertions( have, need, func2 );
959
960 result = true;
961 }
962
963 private:
964 // Returns: other, cast as XInstType
965 // Assigns this->result: whether types are compatible (up to generic parameters)
966 template< typename XInstType >
967 const XInstType * handleRefType( const XInstType * inst, const ast::Type * other ) {
968 // check that the other type is compatible and named the same
969 auto otherInst = dynamic_cast< const XInstType * >( other );
970 if (otherInst && inst->name == otherInst->name) this->result = otherInst;
971 return otherInst;
972 }
973
974 /// Creates a tuple type based on a list of TypeExpr
975 template< typename Iter >
976 static const ast::Type * tupleFromExprs(
977 const ast::TypeExpr * param, Iter & crnt, Iter end, ast::CV::Qualifiers qs
978 ) {
979 std::vector< ast::ptr< ast::Type > > types;
980 do {
981 types.emplace_back( param->type );
982
983 ++crnt;
984 if ( crnt == end ) break;
985 param = strict_dynamic_cast< const ast::TypeExpr * >( crnt->get() );
986 } while(true);
987
988 return new ast::TupleType{ std::move(types), qs };
989 }
990
991 template< typename XInstType >
992 void handleGenericRefType( const XInstType * inst, const ast::Type * other ) {
993 // check that other type is compatible and named the same
994 const XInstType * otherInst = handleRefType( inst, other );
995 if ( ! this->result ) return;
996
997 // check that parameters of types unify, if any
998 const std::vector< ast::ptr< ast::Expr > > & params = inst->params;
999 const std::vector< ast::ptr< ast::Expr > > & params2 = otherInst->params;
1000
1001 auto it = params.begin();
1002 auto jt = params2.begin();
1003 for ( ; it != params.end() && jt != params2.end(); ++it, ++jt ) {
1004 auto param = strict_dynamic_cast< const ast::TypeExpr * >( it->get() );
1005 auto param2 = strict_dynamic_cast< const ast::TypeExpr * >( jt->get() );
1006
1007 ast::ptr< ast::Type > pty = param->type;
1008 ast::ptr< ast::Type > pty2 = param2->type;
1009
1010 bool isTuple = Tuples::isTtype( pty );
1011 bool isTuple2 = Tuples::isTtype( pty2 );
1012
1013 if ( isTuple && isTuple2 ) {
1014 ++it; ++jt; // skip ttype parameters before break
1015 } else if ( isTuple ) {
1016 // bundle remaining params into tuple
1017 pty2 = tupleFromExprs( param2, jt, params2.end(), pty->qualifiers );
1018 ++it; // skip ttype parameter for break
1019 } else if ( isTuple2 ) {
1020 // bundle remaining params into tuple
1021 pty = tupleFromExprs( param, it, params.end(), pty2->qualifiers );
1022 ++jt; // skip ttype parameter for break
1023 }
1024
1025 if ( ! unifyExact(
1026 pty, pty2, tenv, need, have, open, noWiden(), symtab ) ) {
1027 result = false;
1028 return;
1029 }
1030
1031 // ttype parameter should be last
1032 if ( isTuple || isTuple2 ) break;
1033 }
1034 result = it == params.end() && jt == params2.end();
1035 }
1036
1037 public:
1038 void postvisit( const ast::StructInstType * aggrType ) {
1039 handleGenericRefType( aggrType, type2 );
1040 }
1041
1042 void postvisit( const ast::UnionInstType * aggrType ) {
1043 handleGenericRefType( aggrType, type2 );
1044 }
1045
1046 void postvisit( const ast::EnumInstType * aggrType ) {
1047 handleRefType( aggrType, type2 );
1048 }
1049
1050 void postvisit( const ast::TraitInstType * aggrType ) {
1051 handleRefType( aggrType, type2 );
1052 }
1053
1054 void postvisit( const ast::TypeInstType * typeInst ) {
1055 assert( open.find( *typeInst ) == open.end() );
1056 handleRefType( typeInst, type2 );
1057 }
1058
1059 private:
1060 /// Creates a tuple type based on a list of Type
1061
1062 static bool unifyList(
1063 const std::vector< ast::ptr< ast::Type > > & list1,
1064 const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env,
1065 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1066 const ast::SymbolTable & symtab
1067 ) {
1068 auto crnt1 = list1.begin();
1069 auto crnt2 = list2.begin();
1070 while ( crnt1 != list1.end() && crnt2 != list2.end() ) {
1071 const ast::Type * t1 = *crnt1;
1072 const ast::Type * t2 = *crnt2;
1073 bool isTuple1 = Tuples::isTtype( t1 );
1074 bool isTuple2 = Tuples::isTtype( t2 );
1075
1076 // assumes ttype must be last parameter
1077 if ( isTuple1 && ! isTuple2 ) {
1078 // combine entirety of list2, then unify
1079 return unifyExact(
1080 t1, tupleFromTypes( list2 ), env, need, have, open,
1081 noWiden(), symtab );
1082 } else if ( ! isTuple1 && isTuple2 ) {
1083 // combine entirety of list1, then unify
1084 return unifyExact(
1085 tupleFromTypes( list1 ), t2, env, need, have, open,
1086 noWiden(), symtab );
1087 }
1088
1089 if ( ! unifyExact(
1090 t1, t2, env, need, have, open, noWiden(), symtab )
1091 ) return false;
1092
1093 ++crnt1; ++crnt2;
1094 }
1095
1096 if ( crnt1 != list1.end() ) {
1097 // try unifying empty tuple type with ttype
1098 const ast::Type * t1 = *crnt1;
1099 if ( ! Tuples::isTtype( t1 ) ) return false;
1100 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1101 // from Rob's code
1102 return unifyExact(
1103 t1, tupleFromTypes( list2 ), env, need, have, open,
1104 noWiden(), symtab );
1105 } else if ( crnt2 != list2.end() ) {
1106 // try unifying empty tuple with ttype
1107 const ast::Type * t2 = *crnt2;
1108 if ( ! Tuples::isTtype( t2 ) ) return false;
1109 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1110 // from Rob's code
1111 return unifyExact(
1112 tupleFromTypes( list1 ), t2, env, need, have, open,
1113 noWiden(), symtab );
1114 }
1115
1116 return true;
1117 }
1118
1119 public:
1120 void postvisit( const ast::TupleType * tuple ) {
1121 auto tuple2 = dynamic_cast< const ast::TupleType * >( type2 );
1122 if ( ! tuple2 ) return;
1123
1124 ast::Pass<TtypeExpander_new> expander{ tenv };
1125
1126 const ast::Type * flat = tuple->accept( expander );
1127 const ast::Type * flat2 = tuple2->accept( expander );
1128
1129 auto types = flatten( flat );
1130 auto types2 = flatten( flat2 );
1131
1132 result = unifyList( types, types2, tenv, need, have, open, symtab );
1133 }
1134
1135 void postvisit( const ast::VarArgsType * ) {
1136 result = dynamic_cast< const ast::VarArgsType * >( type2 );
1137 }
1138
1139 void postvisit( const ast::ZeroType * ) {
1140 result = dynamic_cast< const ast::ZeroType * >( type2 );
1141 }
1142
1143 void postvisit( const ast::OneType * ) {
1144 result = dynamic_cast< const ast::OneType * >( type2 );
1145 }
1146
1147 private:
1148 template< typename RefType > void handleRefType( RefType *inst, Type *other );
1149 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
1150 };
1151
1152 // size_t Unify_new::traceId = Stats::Heap::new_stacktrace_id("Unify_new");
1153 bool unify(
1154 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1155 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1156 ast::OpenVarSet & open, const ast::SymbolTable & symtab
1157 ) {
1158 ast::ptr<ast::Type> common;
1159 return unify( type1, type2, env, need, have, open, symtab, common );
1160 }
1161
1162 bool unify(
1163 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1164 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1165 ast::OpenVarSet & open, const ast::SymbolTable & symtab, ast::ptr<ast::Type> & common
1166 ) {
1167 ast::OpenVarSet closed;
1168 findOpenVars( type1, open, closed, need, have, FirstClosed );
1169 findOpenVars( type2, open, closed, need, have, FirstOpen );
1170 return unifyInexact(
1171 type1, type2, env, need, have, open, WidenMode{ true, true }, symtab, common );
1172 }
1173
1174 bool unifyExact(
1175 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
1176 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1177 WidenMode widen, const ast::SymbolTable & symtab
1178 ) {
1179 if ( type1->qualifiers != type2->qualifiers ) return false;
1180
1181 auto var1 = dynamic_cast< const ast::TypeInstType * >( type1 );
1182 auto var2 = dynamic_cast< const ast::TypeInstType * >( type2 );
1183 ast::OpenVarSet::const_iterator
1184 entry1 = var1 ? open.find( *var1 ) : open.end(),
1185 entry2 = var2 ? open.find( *var2 ) : open.end();
1186 bool isopen1 = entry1 != open.end();
1187 bool isopen2 = entry2 != open.end();
1188
1189 if ( isopen1 && isopen2 ) {
1190 if ( entry1->second.kind != entry2->second.kind ) return false;
1191 return env.bindVarToVar(
1192 var1, var2, ast::TypeData{ entry1->second, entry2->second }, need, have,
1193 open, widen, symtab );
1194 } else if ( isopen1 ) {
1195 return env.bindVar( var1, type2, entry1->second, need, have, open, widen, symtab );
1196 } else if ( isopen2 ) {
1197 return env.bindVar( var2, type1, entry2->second, need, have, open, widen, symtab );
1198 } else {
1199 return ast::Pass<Unify_new>::read(
1200 type1, type2, env, need, have, open, widen, symtab );
1201 }
1202 }
1203
1204 bool unifyInexact(
1205 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1206 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1207 const ast::OpenVarSet & open, WidenMode widen, const ast::SymbolTable & symtab,
1208 ast::ptr<ast::Type> & common
1209 ) {
1210 ast::CV::Qualifiers q1 = type1->qualifiers, q2 = type2->qualifiers;
1211
1212 // force t1 and t2 to be cloned if their qualifiers must be stripped, so that type1 and
1213 // type2 are left unchanged; calling convention forces type{1,2}->strong_ref >= 1
1214 ast::Type * t1 = shallowCopy(type1.get());
1215 ast::Type * t2 = shallowCopy(type2.get());
1216 t1->qualifiers = {};
1217 t2->qualifiers = {};
1218 ast::ptr< ast::Type > t1_(t1);
1219 ast::ptr< ast::Type > t2_(t2);
1220
1221 if ( unifyExact( t1, t2, env, need, have, open, widen, symtab ) ) {
1222 // if exact unification on unqualified types, try to merge qualifiers
1223 if ( q1 == q2 || ( ( q1 > q2 || widen.first ) && ( q2 > q1 || widen.second ) ) ) {
1224 t1->qualifiers = q1 | q2;
1225 common = t1;
1226 return true;
1227 } else {
1228 return false;
1229 }
1230
1231 } else if (( common = commonType( t1, t2, env, need, have, open, widen, symtab ))) {
1232 // no exact unification, but common type
1233 auto c = shallowCopy(common.get());
1234 c->qualifiers = q1 | q2;
1235 common = c;
1236 return true;
1237 } else {
1238 return false;
1239 }
1240 }
1241
1242 ast::ptr<ast::Type> extractResultType( const ast::FunctionType * func ) {
1243 if ( func->returns.empty() ) return new ast::VoidType{};
1244 if ( func->returns.size() == 1 ) return func->returns[0];
1245
1246 std::vector<ast::ptr<ast::Type>> tys;
1247 for ( const auto & decl : func->returns ) {
1248 tys.emplace_back( decl );
1249 }
1250 return new ast::TupleType{ std::move(tys) };
1251 }
1252} // namespace ResolvExpr
1253
1254// Local Variables: //
1255// tab-width: 4 //
1256// mode: c++ //
1257// compile-command: "make install" //
1258// End: //
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