source: src/ResolvExpr/Unify.cc@ 81da70a5

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 81da70a5 was c7f834e, checked in by Fangren Yu <f37yu@…>, 5 years ago

fix destructed return value in TypeSubstitution
  • Property mode set to 100644
File size: 48.0 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// Unify.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sun May 17 12:27:10 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Fri Dec 13 23:43:05 2019
13// Update Count : 46
14//
15
16#include "Unify.h"
17
18#include <cassert> // for assertf, assert
19#include <iterator> // for back_insert_iterator, back_inserter
20#include <map> // for _Rb_tree_const_iterator, _Rb_tree_i...
21#include <memory> // for unique_ptr
22#include <set> // for set
23#include <string> // for string, operator==, operator!=, bas...
24#include <utility> // for pair, move
25#include <vector>
26
27#include "AST/Copy.hpp"
28#include "AST/Decl.hpp"
29#include "AST/Node.hpp"
30#include "AST/Pass.hpp"
31#include "AST/Print.hpp"
32#include "AST/Type.hpp"
33#include "AST/TypeEnvironment.hpp"
34#include "Common/PassVisitor.h" // for PassVisitor
35#include "FindOpenVars.h" // for findOpenVars
36#include "SynTree/LinkageSpec.h" // for C
37#include "SynTree/Constant.h" // for Constant
38#include "SynTree/Declaration.h" // for TypeDecl, TypeDecl::Data, Declarati...
39#include "SynTree/Expression.h" // for TypeExpr, Expression, ConstantExpr
40#include "SynTree/Mutator.h" // for Mutator
41#include "SynTree/Type.h" // for Type, TypeInstType, FunctionType
42#include "SynTree/Visitor.h" // for Visitor
43#include "Tuples/Tuples.h" // for isTtype
44#include "TypeEnvironment.h" // for EqvClass, AssertionSet, OpenVarSet
45#include "typeops.h" // for flatten, occurs, commonType
46
47namespace ast {
48 class SymbolTable;
49}
50
51namespace SymTab {
52class Indexer;
53} // namespace SymTab
54
55// #define DEBUG
56
57namespace ResolvExpr {
58
59 struct Unify_old : public WithShortCircuiting {
60 Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
61
62 bool get_result() const { return result; }
63
64 void previsit( BaseSyntaxNode * ) { visit_children = false; }
65
66 void postvisit( VoidType * voidType );
67 void postvisit( BasicType * basicType );
68 void postvisit( PointerType * pointerType );
69 void postvisit( ArrayType * arrayType );
70 void postvisit( ReferenceType * refType );
71 void postvisit( FunctionType * functionType );
72 void postvisit( StructInstType * aggregateUseType );
73 void postvisit( UnionInstType * aggregateUseType );
74 void postvisit( EnumInstType * aggregateUseType );
75 void postvisit( TraitInstType * aggregateUseType );
76 void postvisit( TypeInstType * aggregateUseType );
77 void postvisit( TupleType * tupleType );
78 void postvisit( VarArgsType * varArgsType );
79 void postvisit( ZeroType * zeroType );
80 void postvisit( OneType * oneType );
81
82 private:
83 template< typename RefType > void handleRefType( RefType *inst, Type *other );
84 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
85
86 bool result;
87 Type *type2; // inherited
88 TypeEnvironment &env;
89 AssertionSet &needAssertions;
90 AssertionSet &haveAssertions;
91 const OpenVarSet &openVars;
92 WidenMode widen;
93 const SymTab::Indexer &indexer;
94 };
95
96 /// Attempts an inexact unification of type1 and type2.
97 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
98 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common );
99 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
100
101 bool unifyExact(
102 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
103 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
104 WidenMode widen, const ast::SymbolTable & symtab );
105
106 bool typesCompatible( const Type * first, const Type * second, const SymTab::Indexer & indexer, const TypeEnvironment & env ) {
107 TypeEnvironment newEnv;
108 OpenVarSet openVars, closedVars; // added closedVars
109 AssertionSet needAssertions, haveAssertions;
110 Type * newFirst = first->clone(), * newSecond = second->clone();
111 env.apply( newFirst );
112 env.apply( newSecond );
113
114 // do we need to do this? Seems like we do, types should be able to be compatible if they
115 // have free variables that can unify
116 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
117 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
118
119 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
120 delete newFirst;
121 delete newSecond;
122 return result;
123 }
124
125 bool typesCompatible(
126 const ast::Type * first, const ast::Type * second, const ast::SymbolTable & symtab,
127 const ast::TypeEnvironment & env ) {
128 ast::TypeEnvironment newEnv;
129 ast::OpenVarSet open, closed;
130 ast::AssertionSet need, have;
131
132 ast::ptr<ast::Type> newFirst{ first }, newSecond{ second };
133 env.apply( newFirst );
134 env.apply( newSecond );
135
136 findOpenVars( newFirst, open, closed, need, have, FirstClosed );
137 findOpenVars( newSecond, open, closed, need, have, FirstOpen );
138
139 return unifyExact(newFirst, newSecond, newEnv, need, have, open, noWiden(), symtab );
140 }
141
142 bool typesCompatibleIgnoreQualifiers( const Type * first, const Type * second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
143 TypeEnvironment newEnv;
144 OpenVarSet openVars;
145 AssertionSet needAssertions, haveAssertions;
146 Type *newFirst = first->clone(), *newSecond = second->clone();
147 env.apply( newFirst );
148 env.apply( newSecond );
149 newFirst->get_qualifiers() = Type::Qualifiers();
150 newSecond->get_qualifiers() = Type::Qualifiers();
151
152 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
153 delete newFirst;
154 delete newSecond;
155 return result;
156 }
157
158 bool typesCompatibleIgnoreQualifiers(
159 const ast::Type * first, const ast::Type * second, const ast::SymbolTable & symtab,
160 const ast::TypeEnvironment & env ) {
161 ast::TypeEnvironment newEnv;
162 ast::OpenVarSet open;
163 ast::AssertionSet need, have;
164
165 ast::Type * newFirst = shallowCopy( first );
166 ast::Type * newSecond = shallowCopy( second );
167 newFirst ->qualifiers = {};
168 newSecond->qualifiers = {};
169 ast::ptr< ast::Type > t1_(newFirst );
170 ast::ptr< ast::Type > t2_(newSecond);
171
172 ast::ptr< ast::Type > subFirst = env.apply(newFirst).node;
173 ast::ptr< ast::Type > subSecond = env.apply(newSecond).node;
174
175 return unifyExact(
176 subFirst,
177 subSecond,
178 newEnv, need, have, open, noWiden(), symtab );
179 }
180
181 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
182 OpenVarSet closedVars;
183 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
184 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
185 Type *commonType = 0;
186 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
187 if ( commonType ) {
188 delete commonType;
189 } // if
190 return true;
191 } else {
192 return false;
193 } // if
194 }
195
196 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
197 OpenVarSet closedVars;
198 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
199 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
200 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
201 }
202
203 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
204#ifdef DEBUG
205 TypeEnvironment debugEnv( env );
206#endif
207 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
208 return false;
209 }
210
211 bool result;
212 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
213 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
214 OpenVarSet::const_iterator entry1, entry2;
215 if ( var1 ) {
216 entry1 = openVars.find( var1->get_name() );
217 } // if
218 if ( var2 ) {
219 entry2 = openVars.find( var2->get_name() );
220 } // if
221 bool isopen1 = var1 && ( entry1 != openVars.end() );
222 bool isopen2 = var2 && ( entry2 != openVars.end() );
223
224 if ( isopen1 && isopen2 ) {
225 if ( entry1->second.kind != entry2->second.kind ) {
226 result = false;
227 } else {
228 result = env.bindVarToVar(
229 var1, var2, TypeDecl::Data{ entry1->second, entry2->second }, needAssertions,
230 haveAssertions, openVars, widen, indexer );
231 }
232 } else if ( isopen1 ) {
233 result = env.bindVar( var1, type2, entry1->second, needAssertions, haveAssertions, openVars, widen, indexer );
234 } else if ( isopen2 ) { // TODO: swap widen values in call, since type positions are flipped?
235 result = env.bindVar( var2, type1, entry2->second, needAssertions, haveAssertions, openVars, widen, indexer );
236 } else {
237 PassVisitor<Unify_old> comparator( type2, env, needAssertions, haveAssertions, openVars, widen, indexer );
238 type1->accept( comparator );
239 result = comparator.pass.get_result();
240 } // if
241#ifdef DEBUG
242 std::cerr << "============ unifyExact" << std::endl;
243 std::cerr << "type1 is ";
244 type1->print( std::cerr );
245 std::cerr << std::endl << "type2 is ";
246 type2->print( std::cerr );
247 std::cerr << std::endl << "openVars are ";
248 printOpenVarSet( openVars, std::cerr, 8 );
249 std::cerr << std::endl << "input env is " << std::endl;
250 debugEnv.print( std::cerr, 8 );
251 std::cerr << std::endl << "result env is " << std::endl;
252 env.print( std::cerr, 8 );
253 std::cerr << "result is " << result << std::endl;
254#endif
255 return result;
256 }
257
258 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
259 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
260 }
261
262 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common ) {
263 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
264 type1->get_qualifiers() = Type::Qualifiers();
265 type2->get_qualifiers() = Type::Qualifiers();
266 bool result;
267#ifdef DEBUG
268 std::cerr << "unifyInexact type 1 is ";
269 type1->print( std::cerr );
270 std::cerr << " type 2 is ";
271 type2->print( std::cerr );
272 std::cerr << std::endl;
273#endif
274 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widen, indexer ) ) {
275#ifdef DEBUG
276 std::cerr << "unifyInexact: no exact unification found" << std::endl;
277#endif
278 if ( ( common = commonType( type1, type2, widen.first, widen.second, indexer, env, openVars ) ) ) {
279 common->tq = tq1.unify( tq2 );
280#ifdef DEBUG
281 std::cerr << "unifyInexact: common type is ";
282 common->print( std::cerr );
283 std::cerr << std::endl;
284#endif
285 result = true;
286 } else {
287#ifdef DEBUG
288 std::cerr << "unifyInexact: no common type found" << std::endl;
289#endif
290 result = false;
291 } // if
292 } else {
293 if ( tq1 != tq2 ) {
294 if ( ( tq1 > tq2 || widen.first ) && ( tq2 > tq1 || widen.second ) ) {
295 common = type1->clone();
296 common->tq = tq1.unify( tq2 );
297 result = true;
298 } else {
299 result = false;
300 } // if
301 } else {
302 common = type1->clone();
303 common->tq = tq1.unify( tq2 );
304 result = true;
305 } // if
306 } // if
307 type1->get_qualifiers() = tq1;
308 type2->get_qualifiers() = tq2;
309 return result;
310 }
311
312 Unify_old::Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer )
313 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widen( widen ), indexer( indexer ) {
314 }
315
316 void Unify_old::postvisit( __attribute__((unused)) VoidType *voidType) {
317 result = dynamic_cast< VoidType* >( type2 );
318 }
319
320 void Unify_old::postvisit(BasicType *basicType) {
321 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
322 result = basicType->get_kind() == otherBasic->get_kind();
323 } // if
324 }
325
326 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
327 AssertionSet::iterator i = assertions.find( assert );
328 if ( i != assertions.end() ) {
329 i->second.isUsed = true;
330 } // if
331 }
332
333 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
334 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
335 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
336 markAssertionSet( assertion1, *assert );
337 markAssertionSet( assertion2, *assert );
338 } // for
339 } // for
340 }
341
342 void Unify_old::postvisit(PointerType *pointerType) {
343 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
344 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
345 markAssertions( haveAssertions, needAssertions, pointerType );
346 markAssertions( haveAssertions, needAssertions, otherPointer );
347 } // if
348 }
349
350 void Unify_old::postvisit(ReferenceType *refType) {
351 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
352 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
353 markAssertions( haveAssertions, needAssertions, refType );
354 markAssertions( haveAssertions, needAssertions, otherRef );
355 } // if
356 }
357
358 void Unify_old::postvisit(ArrayType *arrayType) {
359 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
360 // to unify, array types must both be VLA or both not VLA
361 // and must both have a dimension expression or not have a dimension
362 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
363
364 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
365 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
366 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
367 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
368 // see C11 Reference Manual 6.7.6.2.6
369 // two array types with size specifiers that are integer constant expressions are
370 // compatible if both size specifiers have the same constant value
371 if ( ce1 && ce2 ) {
372 Constant * c1 = ce1->get_constant();
373 Constant * c2 = ce2->get_constant();
374
375 if ( c1->get_value() != c2->get_value() ) {
376 // does not unify if the dimension is different
377 return;
378 }
379 }
380 }
381
382 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
383 } // if
384 }
385
386 template< typename Iterator, typename Func >
387 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
388 std::list< Type * > types;
389 for ( ; begin != end; ++begin ) {
390 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
391 flatten( toType( *begin ), back_inserter( types ) );
392 }
393 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
394 }
395
396 template< typename Iterator1, typename Iterator2 >
397 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
398 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
399 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
400 Type * t1 = (*list1Begin)->get_type();
401 Type * t2 = (*list2Begin)->get_type();
402 bool isTtype1 = Tuples::isTtype( t1 );
403 bool isTtype2 = Tuples::isTtype( t2 );
404 // xxx - assumes ttype must be last parameter
405 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
406 if ( isTtype1 && ! isTtype2 ) {
407 // combine all of the things in list2, then unify
408 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
409 } else if ( isTtype2 && ! isTtype1 ) {
410 // combine all of the things in list1, then unify
411 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
412 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
413 return false;
414 } // if
415 } // for
416 // may get to the end of one argument list before the end of the other. This is only okay when the other is a ttype
417 if ( list1Begin != list1End ) {
418 // try unifying empty tuple type with ttype
419 Type * t1 = (*list1Begin)->get_type();
420 if ( Tuples::isTtype( t1 ) ) {
421 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
422 } else return false;
423 } else if ( list2Begin != list2End ) {
424 // try unifying empty tuple type with ttype
425 Type * t2 = (*list2Begin)->get_type();
426 if ( Tuples::isTtype( t2 ) ) {
427 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
428 } else return false;
429 } else {
430 return true;
431 } // if
432 }
433
434 /// Finds ttypes and replaces them with their expansion, if known.
435 /// This needs to be done so that satisfying ttype assertions is easier.
436 /// If this isn't done then argument lists can have wildly different
437 /// size and structure, when they should be compatible.
438 struct TtypeExpander_old : public WithShortCircuiting {
439 TypeEnvironment & tenv;
440 TtypeExpander_old( TypeEnvironment & tenv ) : tenv( tenv ) {}
441 void premutate( TypeInstType * ) { visit_children = false; }
442 Type * postmutate( TypeInstType * typeInst ) {
443 if ( const EqvClass *eqvClass = tenv.lookup( typeInst->get_name() ) ) {
444 // expand ttype parameter into its actual type
445 if ( eqvClass->data.kind == TypeDecl::Ttype && eqvClass->type ) {
446 delete typeInst;
447 return eqvClass->type->clone();
448 }
449 }
450 return typeInst;
451 }
452 };
453
454 /// flattens a list of declarations, so that each tuple type has a single declaration.
455 /// makes use of TtypeExpander to ensure ttypes are flat as well.
456 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
457 dst.clear();
458 for ( DeclarationWithType * dcl : src ) {
459 PassVisitor<TtypeExpander_old> expander( env );
460 dcl->acceptMutator( expander );
461 std::list< Type * > types;
462 flatten( dcl->get_type(), back_inserter( types ) );
463 for ( Type * t : types ) {
464 // outermost const, volatile, _Atomic qualifiers in parameters should not play a role in the unification of function types, since they do not determine whether a function is callable.
465 // Note: MUST consider at least mutex qualifier, since functions can be overloaded on outermost mutex and a mutex function has different requirements than a non-mutex function.
466 t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic);
467
468 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
469 }
470 delete dcl;
471 }
472 }
473
474 void Unify_old::postvisit(FunctionType *functionType) {
475 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
476 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
477 // flatten the parameter lists for both functions so that tuple structure
478 // doesn't affect unification. Must be a clone so that the types don't change.
479 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
480 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
481 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
482 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
483
484 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
485 if (
486 (flatFunc->parameters.size() == flatOther->parameters.size() &&
487 flatFunc->returnVals.size() == flatOther->returnVals.size())
488 || flatFunc->isTtype()
489 || flatOther->isTtype()
490 ) {
491 if ( unifyDeclList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
492 if ( unifyDeclList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->returnVals.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
493
494 // the original types must be used in mark assertions, since pointer comparisons are used
495 markAssertions( haveAssertions, needAssertions, functionType );
496 markAssertions( haveAssertions, needAssertions, otherFunction );
497
498 result = true;
499 } // if
500 } // if
501 } // if
502 } // if
503 }
504
505 template< typename RefType >
506 void Unify_old::handleRefType( RefType *inst, Type *other ) {
507 // check that other type is compatible and named the same
508 RefType *otherStruct = dynamic_cast< RefType* >( other );
509 result = otherStruct && inst->name == otherStruct->name;
510 }
511
512 template< typename RefType >
513 void Unify_old::handleGenericRefType( RefType *inst, Type *other ) {
514 // Check that other type is compatible and named the same
515 handleRefType( inst, other );
516 if ( ! result ) return;
517 // Check that parameters of types unify, if any
518 std::list< Expression* > params = inst->parameters;
519 std::list< Expression* > otherParams = ((RefType*)other)->parameters;
520
521 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
522 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
523 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
524 assertf(param, "Aggregate parameters should be type expressions");
525 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
526 assertf(otherParam, "Aggregate parameters should be type expressions");
527
528 Type* paramTy = param->get_type();
529 Type* otherParamTy = otherParam->get_type();
530
531 bool tupleParam = Tuples::isTtype( paramTy );
532 bool otherTupleParam = Tuples::isTtype( otherParamTy );
533
534 if ( tupleParam && otherTupleParam ) {
535 ++it; ++jt; // skip ttype parameters for break
536 } else if ( tupleParam ) {
537 // bundle other parameters into tuple to match
538 std::list< Type * > binderTypes;
539
540 do {
541 binderTypes.push_back( otherParam->get_type()->clone() );
542 ++jt;
543
544 if ( jt == otherParams.end() ) break;
545
546 otherParam = dynamic_cast< TypeExpr* >(*jt);
547 assertf(otherParam, "Aggregate parameters should be type expressions");
548 } while (true);
549
550 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
551 ++it; // skip ttype parameter for break
552 } else if ( otherTupleParam ) {
553 // bundle parameters into tuple to match other
554 std::list< Type * > binderTypes;
555
556 do {
557 binderTypes.push_back( param->get_type()->clone() );
558 ++it;
559
560 if ( it == params.end() ) break;
561
562 param = dynamic_cast< TypeExpr* >(*it);
563 assertf(param, "Aggregate parameters should be type expressions");
564 } while (true);
565
566 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
567 ++jt; // skip ttype parameter for break
568 }
569
570 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
571 result = false;
572 return;
573 }
574
575 // ttype parameter should be last
576 if ( tupleParam || otherTupleParam ) break;
577 }
578 result = ( it == params.end() && jt == otherParams.end() );
579 }
580
581 void Unify_old::postvisit(StructInstType *structInst) {
582 handleGenericRefType( structInst, type2 );
583 }
584
585 void Unify_old::postvisit(UnionInstType *unionInst) {
586 handleGenericRefType( unionInst, type2 );
587 }
588
589 void Unify_old::postvisit(EnumInstType *enumInst) {
590 handleRefType( enumInst, type2 );
591 }
592
593 void Unify_old::postvisit(TraitInstType *contextInst) {
594 handleRefType( contextInst, type2 );
595 }
596
597 void Unify_old::postvisit(TypeInstType *typeInst) {
598 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
599 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
600 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
601 result = true;
602/// } else {
603/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
604/// if ( nt ) {
605/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
606/// assert( type );
607/// if ( type->get_base() ) {
608/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
609/// }
610/// }
611 } // if
612 }
613
614 template< typename Iterator1, typename Iterator2 >
615 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
616 auto get_type = [](Type * t) { return t; };
617 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
618 Type * t1 = *list1Begin;
619 Type * t2 = *list2Begin;
620 bool isTtype1 = Tuples::isTtype( t1 );
621 bool isTtype2 = Tuples::isTtype( t2 );
622 // xxx - assumes ttype must be last parameter
623 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
624 if ( isTtype1 && ! isTtype2 ) {
625 // combine all of the things in list2, then unify
626 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
627 } else if ( isTtype2 && ! isTtype1 ) {
628 // combine all of the things in list1, then unify
629 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
630 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
631 return false;
632 } // if
633
634 } // for
635 if ( list1Begin != list1End ) {
636 // try unifying empty tuple type with ttype
637 Type * t1 = *list1Begin;
638 if ( Tuples::isTtype( t1 ) ) {
639 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
640 } else return false;
641 } else if ( list2Begin != list2End ) {
642 // try unifying empty tuple type with ttype
643 Type * t2 = *list2Begin;
644 if ( Tuples::isTtype( t2 ) ) {
645 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
646 } else return false;
647 } else {
648 return true;
649 } // if
650 }
651
652 void Unify_old::postvisit(TupleType *tupleType) {
653 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
654 std::unique_ptr<TupleType> flat1( tupleType->clone() );
655 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
656 std::list<Type *> types1, types2;
657
658 PassVisitor<TtypeExpander_old> expander( env );
659 flat1->acceptMutator( expander );
660 flat2->acceptMutator( expander );
661
662 flatten( flat1.get(), back_inserter( types1 ) );
663 flatten( flat2.get(), back_inserter( types2 ) );
664
665 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
666 } // if
667 }
668
669 void Unify_old::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) {
670 result = dynamic_cast< VarArgsType* >( type2 );
671 }
672
673 void Unify_old::postvisit( __attribute__((unused)) ZeroType *zeroType ) {
674 result = dynamic_cast< ZeroType* >( type2 );
675 }
676
677 void Unify_old::postvisit( __attribute__((unused)) OneType *oneType ) {
678 result = dynamic_cast< OneType* >( type2 );
679 }
680
681 Type * extractResultType( FunctionType * function ) {
682 if ( function->get_returnVals().size() == 0 ) {
683 return new VoidType( Type::Qualifiers() );
684 } else if ( function->get_returnVals().size() == 1 ) {
685 return function->get_returnVals().front()->get_type()->clone();
686 } else {
687 std::list< Type * > types;
688 for ( DeclarationWithType * decl : function->get_returnVals() ) {
689 types.push_back( decl->get_type()->clone() );
690 } // for
691 return new TupleType( Type::Qualifiers(), types );
692 }
693 }
694
695 class Unify_new final : public ast::WithShortCircuiting {
696 const ast::Type * type2;
697 ast::TypeEnvironment & tenv;
698 ast::AssertionSet & need;
699 ast::AssertionSet & have;
700 const ast::OpenVarSet & open;
701 WidenMode widen;
702 const ast::SymbolTable & symtab;
703 public:
704 bool result;
705
706 Unify_new(
707 const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need,
708 ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen,
709 const ast::SymbolTable & symtab )
710 : type2(type2), tenv(env), need(need), have(have), open(open), widen(widen),
711 symtab(symtab), result(false) {}
712
713 void previsit( const ast::Node * ) { visit_children = false; }
714
715 void postvisit( const ast::VoidType * ) {
716 result = dynamic_cast< const ast::VoidType * >( type2 );
717 }
718
719 void postvisit( const ast::BasicType * basic ) {
720 if ( auto basic2 = dynamic_cast< const ast::BasicType * >( type2 ) ) {
721 result = basic->kind == basic2->kind;
722 }
723 }
724
725 void postvisit( const ast::PointerType * pointer ) {
726 if ( auto pointer2 = dynamic_cast< const ast::PointerType * >( type2 ) ) {
727 result = unifyExact(
728 pointer->base, pointer2->base, tenv, need, have, open,
729 noWiden(), symtab );
730 }
731 }
732
733 void postvisit( const ast::ArrayType * array ) {
734 auto array2 = dynamic_cast< const ast::ArrayType * >( type2 );
735 if ( ! array2 ) return;
736
737 // to unify, array types must both be VLA or both not VLA and both must have a
738 // dimension expression or not have a dimension
739 if ( array->isVarLen != array2->isVarLen ) return;
740 if ( ! array->isVarLen && ! array2->isVarLen
741 && array->dimension && array2->dimension ) {
742 auto ce1 = array->dimension.as< ast::ConstantExpr >();
743 auto ce2 = array2->dimension.as< ast::ConstantExpr >();
744
745 // see C11 Reference Manual 6.7.6.2.6
746 // two array types with size specifiers that are integer constant expressions are
747 // compatible if both size specifiers have the same constant value
748 if ( ce1 && ce2 && ce1->intValue() != ce2->intValue() ) return;
749 }
750
751 result = unifyExact(
752 array->base, array2->base, tenv, need, have, open, noWiden(),
753 symtab );
754 }
755
756 void postvisit( const ast::ReferenceType * ref ) {
757 if ( auto ref2 = dynamic_cast< const ast::ReferenceType * >( type2 ) ) {
758 result = unifyExact(
759 ref->base, ref2->base, tenv, need, have, open, noWiden(),
760 symtab );
761 }
762 }
763
764 private:
765 /// Replaces ttype variables with their bound types.
766 /// If this isn't done when satifying ttype assertions, then argument lists can have
767 /// different size and structure when they should be compatible.
768 struct TtypeExpander_new : public ast::WithShortCircuiting {
769 ast::TypeEnvironment & tenv;
770
771 TtypeExpander_new( ast::TypeEnvironment & env ) : tenv( env ) {}
772
773 const ast::Type * postvisit( const ast::TypeInstType * typeInst ) {
774 if ( const ast::EqvClass * clz = tenv.lookup( typeInst->name ) ) {
775 // expand ttype parameter into its actual type
776 if ( clz->data.kind == ast::TypeDecl::Ttype && clz->bound ) {
777 return clz->bound;
778 }
779 }
780 return typeInst;
781 }
782 };
783
784 /// returns flattened version of `src`
785 static std::vector< ast::ptr< ast::DeclWithType > > flattenList(
786 const std::vector< ast::ptr< ast::DeclWithType > > & src, ast::TypeEnvironment & env
787 ) {
788 std::vector< ast::ptr< ast::DeclWithType > > dst;
789 dst.reserve( src.size() );
790 for ( const ast::DeclWithType * d : src ) {
791 ast::Pass<TtypeExpander_new> expander{ env };
792 d = d->accept( expander );
793 auto types = flatten( d->get_type() );
794 for ( ast::ptr< ast::Type > & t : types ) {
795 // outermost const, volatile, _Atomic qualifiers in parameters should not play
796 // a role in the unification of function types, since they do not determine
797 // whether a function is callable.
798 // NOTE: **must** consider at least mutex qualifier, since functions can be
799 // overloaded on outermost mutex and a mutex function has different
800 // requirements than a non-mutex function
801 remove_qualifiers( t, ast::CV::Const | ast::CV::Volatile | ast::CV::Atomic );
802 dst.emplace_back( new ast::ObjectDecl{ d->location, "", t } );
803 }
804 }
805 return dst;
806 }
807
808 /// Creates a tuple type based on a list of DeclWithType
809 template< typename Iter >
810 static ast::ptr< ast::Type > tupleFromDecls( Iter crnt, Iter end ) {
811 std::vector< ast::ptr< ast::Type > > types;
812 while ( crnt != end ) {
813 // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure
814 // that this results in a flat tuple
815 flatten( (*crnt)->get_type(), types );
816
817 ++crnt;
818 }
819
820 return { new ast::TupleType{ std::move(types) } };
821 }
822
823 template< typename Iter >
824 static bool unifyDeclList(
825 Iter crnt1, Iter end1, Iter crnt2, Iter end2, ast::TypeEnvironment & env,
826 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
827 const ast::SymbolTable & symtab
828 ) {
829 while ( crnt1 != end1 && crnt2 != end2 ) {
830 const ast::Type * t1 = (*crnt1)->get_type();
831 const ast::Type * t2 = (*crnt2)->get_type();
832 bool isTuple1 = Tuples::isTtype( t1 );
833 bool isTuple2 = Tuples::isTtype( t2 );
834
835 // assumes here that ttype *must* be last parameter
836 if ( isTuple1 && ! isTuple2 ) {
837 // combine remainder of list2, then unify
838 return unifyExact(
839 t1, tupleFromDecls( crnt2, end2 ), env, need, have, open,
840 noWiden(), symtab );
841 } else if ( ! isTuple1 && isTuple2 ) {
842 // combine remainder of list1, then unify
843 return unifyExact(
844 tupleFromDecls( crnt1, end1 ), t2, env, need, have, open,
845 noWiden(), symtab );
846 }
847
848 if ( ! unifyExact(
849 t1, t2, env, need, have, open, noWiden(), symtab )
850 ) return false;
851
852 ++crnt1; ++crnt2;
853 }
854
855 // May get to the end of one argument list before the other. This is only okay if the
856 // other is a ttype
857 if ( crnt1 != end1 ) {
858 // try unifying empty tuple with ttype
859 const ast::Type * t1 = (*crnt1)->get_type();
860 if ( ! Tuples::isTtype( t1 ) ) return false;
861 return unifyExact(
862 t1, tupleFromDecls( crnt2, end2 ), env, need, have, open,
863 noWiden(), symtab );
864 } else if ( crnt2 != end2 ) {
865 // try unifying empty tuple with ttype
866 const ast::Type * t2 = (*crnt2)->get_type();
867 if ( ! Tuples::isTtype( t2 ) ) return false;
868 return unifyExact(
869 tupleFromDecls( crnt1, end1 ), t2, env, need, have, open,
870 noWiden(), symtab );
871 }
872
873 return true;
874 }
875
876 static bool unifyDeclList(
877 const std::vector< ast::ptr< ast::DeclWithType > > & list1,
878 const std::vector< ast::ptr< ast::DeclWithType > > & list2,
879 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
880 const ast::OpenVarSet & open, const ast::SymbolTable & symtab
881 ) {
882 return unifyDeclList(
883 list1.begin(), list1.end(), list2.begin(), list2.end(), env, need, have, open,
884 symtab );
885 }
886
887 static void markAssertionSet( ast::AssertionSet & assns, const ast::DeclWithType * assn ) {
888 auto i = assns.find( assn );
889 if ( i != assns.end() ) {
890 i->second.isUsed = true;
891 }
892 }
893
894 /// mark all assertions in `type` used in both `assn1` and `assn2`
895 static void markAssertions(
896 ast::AssertionSet & assn1, ast::AssertionSet & assn2,
897 const ast::ParameterizedType * type
898 ) {
899 for ( const auto & tyvar : type->forall ) {
900 for ( const ast::DeclWithType * assert : tyvar->assertions ) {
901 markAssertionSet( assn1, assert );
902 markAssertionSet( assn2, assert );
903 }
904 }
905 }
906
907 public:
908 void postvisit( const ast::FunctionType * func ) {
909 auto func2 = dynamic_cast< const ast::FunctionType * >( type2 );
910 if ( ! func2 ) return;
911
912 if ( func->isVarArgs != func2->isVarArgs ) return;
913
914 // Flatten the parameter lists for both functions so that tuple structure does not
915 // affect unification. Does not actually mutate function parameters.
916 auto params = flattenList( func->params, tenv );
917 auto params2 = flattenList( func2->params, tenv );
918
919 // sizes don't have to match if ttypes are involved; need to be more precise w.r.t.
920 // where the ttype is to prevent errors
921 if (
922 ( params.size() != params2.size() || func->returns.size() != func2->returns.size() )
923 && ! func->isTtype()
924 && ! func2->isTtype()
925 ) return;
926
927 if ( ! unifyDeclList( params, params2, tenv, need, have, open, symtab ) ) return;
928 if ( ! unifyDeclList(
929 func->returns, func2->returns, tenv, need, have, open, symtab ) ) return;
930
931 markAssertions( have, need, func );
932 markAssertions( have, need, func2 );
933
934 result = true;
935 }
936
937 private:
938 // Returns: other, cast as XInstType
939 // Assigns this->result: whether types are compatible (up to generic parameters)
940 template< typename XInstType >
941 const XInstType * handleRefType( const XInstType * inst, const ast::Type * other ) {
942 // check that the other type is compatible and named the same
943 auto otherInst = dynamic_cast< const XInstType * >( other );
944 this->result = otherInst && inst->name == otherInst->name;
945 return otherInst;
946 }
947
948 /// Creates a tuple type based on a list of TypeExpr
949 template< typename Iter >
950 static const ast::Type * tupleFromExprs(
951 const ast::TypeExpr * param, Iter & crnt, Iter end, ast::CV::Qualifiers qs
952 ) {
953 std::vector< ast::ptr< ast::Type > > types;
954 do {
955 types.emplace_back( param->type );
956
957 ++crnt;
958 if ( crnt == end ) break;
959 param = strict_dynamic_cast< const ast::TypeExpr * >( crnt->get() );
960 } while(true);
961
962 return new ast::TupleType{ std::move(types), qs };
963 }
964
965 template< typename XInstType >
966 void handleGenericRefType( const XInstType * inst, const ast::Type * other ) {
967 // check that other type is compatible and named the same
968 const XInstType * otherInst = handleRefType( inst, other );
969 if ( ! this->result ) return;
970
971 // check that parameters of types unify, if any
972 const std::vector< ast::ptr< ast::Expr > > & params = inst->params;
973 const std::vector< ast::ptr< ast::Expr > > & params2 = otherInst->params;
974
975 auto it = params.begin();
976 auto jt = params2.begin();
977 for ( ; it != params.end() && jt != params2.end(); ++it, ++jt ) {
978 auto param = strict_dynamic_cast< const ast::TypeExpr * >( it->get() );
979 auto param2 = strict_dynamic_cast< const ast::TypeExpr * >( jt->get() );
980
981 ast::ptr< ast::Type > pty = param->type;
982 ast::ptr< ast::Type > pty2 = param2->type;
983
984 bool isTuple = Tuples::isTtype( pty );
985 bool isTuple2 = Tuples::isTtype( pty2 );
986
987 if ( isTuple && isTuple2 ) {
988 ++it; ++jt; // skip ttype parameters before break
989 } else if ( isTuple ) {
990 // bundle remaining params into tuple
991 pty2 = tupleFromExprs( param2, jt, params2.end(), pty->qualifiers );
992 ++it; // skip ttype parameter for break
993 } else if ( isTuple2 ) {
994 // bundle remaining params into tuple
995 pty = tupleFromExprs( param, it, params.end(), pty2->qualifiers );
996 ++jt; // skip ttype parameter for break
997 }
998
999 if ( ! unifyExact(
1000 pty, pty2, tenv, need, have, open, noWiden(), symtab ) ) {
1001 result = false;
1002 return;
1003 }
1004
1005 // ttype parameter should be last
1006 if ( isTuple || isTuple2 ) break;
1007 }
1008 result = it == params.end() && jt == params2.end();
1009 }
1010
1011 public:
1012 void postvisit( const ast::StructInstType * aggrType ) {
1013 handleGenericRefType( aggrType, type2 );
1014 }
1015
1016 void postvisit( const ast::UnionInstType * aggrType ) {
1017 handleGenericRefType( aggrType, type2 );
1018 }
1019
1020 void postvisit( const ast::EnumInstType * aggrType ) {
1021 handleRefType( aggrType, type2 );
1022 }
1023
1024 void postvisit( const ast::TraitInstType * aggrType ) {
1025 handleRefType( aggrType, type2 );
1026 }
1027
1028 void postvisit( const ast::TypeInstType * typeInst ) {
1029 assert( open.find( typeInst->name ) == open.end() );
1030 handleRefType( typeInst, type2 );
1031 }
1032
1033 private:
1034 /// Creates a tuple type based on a list of Type
1035 static ast::ptr< ast::Type > tupleFromTypes(
1036 const std::vector< ast::ptr< ast::Type > > & tys
1037 ) {
1038 std::vector< ast::ptr< ast::Type > > out;
1039 for ( const ast::Type * ty : tys ) {
1040 // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure
1041 // that this results in a flat tuple
1042 flatten( ty, out );
1043 }
1044
1045 return { new ast::TupleType{ std::move(out) } };
1046 }
1047
1048 static bool unifyList(
1049 const std::vector< ast::ptr< ast::Type > > & list1,
1050 const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env,
1051 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1052 const ast::SymbolTable & symtab
1053 ) {
1054 auto crnt1 = list1.begin();
1055 auto crnt2 = list2.begin();
1056 while ( crnt1 != list1.end() && crnt2 != list2.end() ) {
1057 const ast::Type * t1 = *crnt1;
1058 const ast::Type * t2 = *crnt2;
1059 bool isTuple1 = Tuples::isTtype( t1 );
1060 bool isTuple2 = Tuples::isTtype( t2 );
1061
1062 // assumes ttype must be last parameter
1063 if ( isTuple1 && ! isTuple2 ) {
1064 // combine entirety of list2, then unify
1065 return unifyExact(
1066 t1, tupleFromTypes( list2 ), env, need, have, open,
1067 noWiden(), symtab );
1068 } else if ( ! isTuple1 && isTuple2 ) {
1069 // combine entirety of list1, then unify
1070 return unifyExact(
1071 tupleFromTypes( list1 ), t2, env, need, have, open,
1072 noWiden(), symtab );
1073 }
1074
1075 if ( ! unifyExact(
1076 t1, t2, env, need, have, open, noWiden(), symtab )
1077 ) return false;
1078
1079 ++crnt1; ++crnt2;
1080 }
1081
1082 if ( crnt1 != list1.end() ) {
1083 // try unifying empty tuple type with ttype
1084 const ast::Type * t1 = *crnt1;
1085 if ( ! Tuples::isTtype( t1 ) ) return false;
1086 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1087 // from Rob's code
1088 return unifyExact(
1089 t1, tupleFromTypes( list2 ), env, need, have, open,
1090 noWiden(), symtab );
1091 } else if ( crnt2 != list2.end() ) {
1092 // try unifying empty tuple with ttype
1093 const ast::Type * t2 = *crnt2;
1094 if ( ! Tuples::isTtype( t2 ) ) return false;
1095 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1096 // from Rob's code
1097 return unifyExact(
1098 tupleFromTypes( list1 ), t2, env, need, have, open,
1099 noWiden(), symtab );
1100 }
1101
1102 return true;
1103 }
1104
1105 public:
1106 void postvisit( const ast::TupleType * tuple ) {
1107 auto tuple2 = dynamic_cast< const ast::TupleType * >( type2 );
1108 if ( ! tuple2 ) return;
1109
1110 ast::Pass<TtypeExpander_new> expander{ tenv };
1111 const ast::Type * flat = tuple->accept( expander );
1112 const ast::Type * flat2 = tuple2->accept( expander );
1113
1114 auto types = flatten( flat );
1115 auto types2 = flatten( flat2 );
1116
1117 result = unifyList( types, types2, tenv, need, have, open, symtab );
1118 }
1119
1120 void postvisit( const ast::VarArgsType * ) {
1121 result = dynamic_cast< const ast::VarArgsType * >( type2 );
1122 }
1123
1124 void postvisit( const ast::ZeroType * ) {
1125 result = dynamic_cast< const ast::ZeroType * >( type2 );
1126 }
1127
1128 void postvisit( const ast::OneType * ) {
1129 result = dynamic_cast< const ast::OneType * >( type2 );
1130 }
1131
1132 private:
1133 template< typename RefType > void handleRefType( RefType *inst, Type *other );
1134 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
1135 };
1136
1137 bool unify(
1138 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1139 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1140 ast::OpenVarSet & open, const ast::SymbolTable & symtab
1141 ) {
1142 ast::ptr<ast::Type> common;
1143 return unify( type1, type2, env, need, have, open, symtab, common );
1144 }
1145
1146 bool unify(
1147 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1148 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1149 ast::OpenVarSet & open, const ast::SymbolTable & symtab, ast::ptr<ast::Type> & common
1150 ) {
1151 ast::OpenVarSet closed;
1152 findOpenVars( type1, open, closed, need, have, FirstClosed );
1153 findOpenVars( type2, open, closed, need, have, FirstOpen );
1154 return unifyInexact(
1155 type1, type2, env, need, have, open, WidenMode{ true, true }, symtab, common );
1156 }
1157
1158 bool unifyExact(
1159 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
1160 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1161 WidenMode widen, const ast::SymbolTable & symtab
1162 ) {
1163 if ( type1->qualifiers != type2->qualifiers ) return false;
1164
1165 auto var1 = dynamic_cast< const ast::TypeInstType * >( type1 );
1166 auto var2 = dynamic_cast< const ast::TypeInstType * >( type2 );
1167 ast::OpenVarSet::const_iterator
1168 entry1 = var1 ? open.find( var1->name ) : open.end(),
1169 entry2 = var2 ? open.find( var2->name ) : open.end();
1170 bool isopen1 = entry1 != open.end();
1171 bool isopen2 = entry2 != open.end();
1172
1173 if ( isopen1 && isopen2 ) {
1174 if ( entry1->second.kind != entry2->second.kind ) return false;
1175 return env.bindVarToVar(
1176 var1, var2, ast::TypeDecl::Data{ entry1->second, entry2->second }, need, have,
1177 open, widen, symtab );
1178 } else if ( isopen1 ) {
1179 return env.bindVar( var1, type2, entry1->second, need, have, open, widen, symtab );
1180 } else if ( isopen2 ) {
1181 return env.bindVar( var2, type1, entry2->second, need, have, open, widen, symtab );
1182 } else {
1183 ast::Pass<Unify_new> comparator{ type2, env, need, have, open, widen, symtab };
1184 type1->accept( comparator );
1185 return comparator.pass.result;
1186 }
1187 }
1188
1189 bool unifyInexact(
1190 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1191 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1192 const ast::OpenVarSet & open, WidenMode widen, const ast::SymbolTable & symtab,
1193 ast::ptr<ast::Type> & common
1194 ) {
1195 ast::CV::Qualifiers q1 = type1->qualifiers, q2 = type2->qualifiers;
1196
1197 // force t1 and t2 to be cloned if their qualifiers must be stripped, so that type1 and
1198 // type2 are left unchanged; calling convention forces type{1,2}->strong_ref >= 1
1199 ast::Type * t1 = shallowCopy(type1.get());
1200 ast::Type * t2 = shallowCopy(type2.get());
1201 t1->qualifiers = {};
1202 t2->qualifiers = {};
1203 ast::ptr< ast::Type > t1_(t1);
1204 ast::ptr< ast::Type > t2_(t2);
1205
1206 if ( unifyExact( t1, t2, env, need, have, open, widen, symtab ) ) {
1207 // if exact unification on unqualified types, try to merge qualifiers
1208 if ( q1 == q2 || ( ( q1 > q2 || widen.first ) && ( q2 > q1 || widen.second ) ) ) {
1209 t1->qualifiers = q1 | q2;
1210 common = t1;
1211 return true;
1212 } else {
1213 return false;
1214 }
1215
1216 } else if (( common = commonType( t1, t2, widen, symtab, env, open ) )) {
1217 // no exact unification, but common type
1218 auto c = shallowCopy(common.get());
1219 c->qualifiers = q1 | q2;
1220 common = c;
1221 return true;
1222 } else {
1223 return false;
1224 }
1225 }
1226
1227 ast::ptr<ast::Type> extractResultType( const ast::FunctionType * func ) {
1228 if ( func->returns.empty() ) return new ast::VoidType{};
1229 if ( func->returns.size() == 1 ) return func->returns[0]->get_type();
1230
1231 std::vector<ast::ptr<ast::Type>> tys;
1232 for ( const ast::DeclWithType * decl : func->returns ) {
1233 tys.emplace_back( decl->get_type() );
1234 }
1235 return new ast::TupleType{ std::move(tys) };
1236 }
1237} // namespace ResolvExpr
1238
1239// Local Variables: //
1240// tab-width: 4 //
1241// mode: c++ //
1242// compile-command: "make install" //
1243// End: //
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