source: src/ResolvExpr/Unify.cc@ 0f6a7752

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 0f6a7752 was 2773ab8, checked in by Aaron Moss <a3moss@…>, 6 years ago

Add new resolver overload for WaitForStmt
  • Property mode set to 100644
File size: 48.4 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 : Aaron B. Moss
12// Last Modified On : Mon Jun 18 11:58:00 2018
13// Update Count : 43
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/Decl.hpp"
28#include "AST/Node.hpp"
29#include "AST/Pass.hpp"
30#include "AST/Type.hpp"
31#include "AST/TypeEnvironment.hpp"
32#include "Common/PassVisitor.h" // for PassVisitor
33#include "FindOpenVars.h" // for findOpenVars
34#include "Parser/LinkageSpec.h" // for C
35#include "SynTree/Constant.h" // for Constant
36#include "SynTree/Declaration.h" // for TypeDecl, TypeDecl::Data, Declarati...
37#include "SynTree/Expression.h" // for TypeExpr, Expression, ConstantExpr
38#include "SynTree/Mutator.h" // for Mutator
39#include "SynTree/Type.h" // for Type, TypeInstType, FunctionType
40#include "SynTree/Visitor.h" // for Visitor
41#include "Tuples/Tuples.h" // for isTtype
42#include "TypeEnvironment.h" // for EqvClass, AssertionSet, OpenVarSet
43#include "typeops.h" // for flatten, occurs, commonType
44
45namespace ast {
46 class SymbolTable;
47}
48
49namespace SymTab {
50class Indexer;
51} // namespace SymTab
52
53// #define DEBUG
54
55namespace ResolvExpr {
56
57 struct Unify_old : public WithShortCircuiting {
58 Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
59
60 bool get_result() const { return result; }
61
62 void previsit( BaseSyntaxNode * ) { visit_children = false; }
63
64 void postvisit( VoidType * voidType );
65 void postvisit( BasicType * basicType );
66 void postvisit( PointerType * pointerType );
67 void postvisit( ArrayType * arrayType );
68 void postvisit( ReferenceType * refType );
69 void postvisit( FunctionType * functionType );
70 void postvisit( StructInstType * aggregateUseType );
71 void postvisit( UnionInstType * aggregateUseType );
72 void postvisit( EnumInstType * aggregateUseType );
73 void postvisit( TraitInstType * aggregateUseType );
74 void postvisit( TypeInstType * aggregateUseType );
75 void postvisit( TupleType * tupleType );
76 void postvisit( VarArgsType * varArgsType );
77 void postvisit( ZeroType * zeroType );
78 void postvisit( OneType * oneType );
79
80 private:
81 template< typename RefType > void handleRefType( RefType *inst, Type *other );
82 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
83
84 bool result;
85 Type *type2; // inherited
86 TypeEnvironment &env;
87 AssertionSet &needAssertions;
88 AssertionSet &haveAssertions;
89 const OpenVarSet &openVars;
90 WidenMode widen;
91 const SymTab::Indexer &indexer;
92 };
93
94 /// Attempts an inexact unification of type1 and type2.
95 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
96 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common );
97 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
98
99 bool unifyExact(
100 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
101 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
102 WidenMode widen, const ast::SymbolTable & symtab );
103
104 bool typesCompatible( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
105 TypeEnvironment newEnv;
106 OpenVarSet openVars, closedVars; // added closedVars
107 AssertionSet needAssertions, haveAssertions;
108 Type *newFirst = first->clone(), *newSecond = second->clone();
109 env.apply( newFirst );
110 env.apply( newSecond );
111
112 // do we need to do this? Seems like we do, types should be able to be compatible if they
113 // have free variables that can unify
114 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
115 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
116
117 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
118 delete newFirst;
119 delete newSecond;
120 return result;
121 }
122
123 bool typesCompatible(
124 const ast::Type * first, const ast::Type * second, const ast::SymbolTable & symtab,
125 const ast::TypeEnvironment & env ) {
126 ast::TypeEnvironment newEnv;
127 ast::OpenVarSet open, closed;
128 ast::AssertionSet need, have;
129
130 ast::ptr<ast::Type> newFirst{ first }, newSecond{ second };
131 env.apply( newFirst );
132 env.apply( newSecond );
133
134 findOpenVars( newFirst, open, closed, need, have, FirstClosed );
135 findOpenVars( newSecond, open, closed, need, have, FirstOpen );
136
137 return unifyExact(
138 newFirst, newSecond, newEnv, need, have, open, noWiden(), symtab );
139 }
140
141 bool typesCompatibleIgnoreQualifiers( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
142 TypeEnvironment newEnv;
143 OpenVarSet openVars;
144 AssertionSet needAssertions, haveAssertions;
145 Type *newFirst = first->clone(), *newSecond = second->clone();
146 env.apply( newFirst );
147 env.apply( newSecond );
148 newFirst->get_qualifiers() = Type::Qualifiers();
149 newSecond->get_qualifiers() = Type::Qualifiers();
150/// std::cerr << "first is ";
151/// first->print( std::cerr );
152/// std::cerr << std::endl << "second is ";
153/// second->print( std::cerr );
154/// std::cerr << std::endl << "newFirst is ";
155/// newFirst->print( std::cerr );
156/// std::cerr << std::endl << "newSecond is ";
157/// newSecond->print( std::cerr );
158/// std::cerr << std::endl;
159 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
160 delete newFirst;
161 delete newSecond;
162 return result;
163 }
164
165 bool typesCompatibleIgnoreQualifiers(
166 const ast::Type * first, const ast::Type * second, const ast::SymbolTable & symtab,
167 const ast::TypeEnvironment & env ) {
168 ast::TypeEnvironment newEnv;
169 ast::OpenVarSet open;
170 ast::AssertionSet need, have;
171
172 ast::ptr<ast::Type> newFirst{ first }, newSecond{ second };
173 env.apply( newFirst );
174 env.apply( newSecond );
175 reset_qualifiers( newFirst );
176 reset_qualifiers( newSecond );
177
178 return unifyExact(
179 newFirst, newSecond, newEnv, need, have, open, noWiden(), symtab );
180 }
181
182 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
183 OpenVarSet closedVars;
184 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
185 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
186 Type *commonType = 0;
187 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
188 if ( commonType ) {
189 delete commonType;
190 } // if
191 return true;
192 } else {
193 return false;
194 } // if
195 }
196
197 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
198 OpenVarSet closedVars;
199 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
200 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
201 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
202 }
203
204 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
205#ifdef DEBUG
206 TypeEnvironment debugEnv( env );
207#endif
208 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
209 return false;
210 }
211
212 bool result;
213 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
214 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
215 OpenVarSet::const_iterator entry1, entry2;
216 if ( var1 ) {
217 entry1 = openVars.find( var1->get_name() );
218 } // if
219 if ( var2 ) {
220 entry2 = openVars.find( var2->get_name() );
221 } // if
222 bool isopen1 = var1 && ( entry1 != openVars.end() );
223 bool isopen2 = var2 && ( entry2 != openVars.end() );
224
225 if ( isopen1 && isopen2 ) {
226 if ( entry1->second.kind != entry2->second.kind ) {
227 result = false;
228 } else {
229 result = env.bindVarToVar(
230 var1, var2, TypeDecl::Data{ entry1->second, entry2->second }, needAssertions,
231 haveAssertions, openVars, widen, indexer );
232 }
233 } else if ( isopen1 ) {
234 result = env.bindVar( var1, type2, entry1->second, needAssertions, haveAssertions, openVars, widen, indexer );
235 } else if ( isopen2 ) { // TODO: swap widen values in call, since type positions are flipped?
236 result = env.bindVar( var2, type1, entry2->second, needAssertions, haveAssertions, openVars, widen, indexer );
237 } else {
238 PassVisitor<Unify_old> comparator( type2, env, needAssertions, haveAssertions, openVars, widen, indexer );
239 type1->accept( comparator );
240 result = comparator.pass.get_result();
241 } // if
242#ifdef DEBUG
243 std::cerr << "============ unifyExact" << std::endl;
244 std::cerr << "type1 is ";
245 type1->print( std::cerr );
246 std::cerr << std::endl << "type2 is ";
247 type2->print( std::cerr );
248 std::cerr << std::endl << "openVars are ";
249 printOpenVarSet( openVars, std::cerr, 8 );
250 std::cerr << std::endl << "input env is " << std::endl;
251 debugEnv.print( std::cerr, 8 );
252 std::cerr << std::endl << "result env is " << std::endl;
253 env.print( std::cerr, 8 );
254 std::cerr << "result is " << result << std::endl;
255#endif
256 return result;
257 }
258
259 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
260 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
261 }
262
263 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common ) {
264 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
265 type1->get_qualifiers() = Type::Qualifiers();
266 type2->get_qualifiers() = Type::Qualifiers();
267 bool result;
268#ifdef DEBUG
269 std::cerr << "unifyInexact type 1 is ";
270 type1->print( std::cerr );
271 std::cerr << " type 2 is ";
272 type2->print( std::cerr );
273 std::cerr << std::endl;
274#endif
275 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widen, indexer ) ) {
276#ifdef DEBUG
277 std::cerr << "unifyInexact: no exact unification found" << std::endl;
278#endif
279 if ( ( common = commonType( type1, type2, widen.first, widen.second, indexer, env, openVars ) ) ) {
280 common->get_qualifiers() = tq1 | tq2;
281#ifdef DEBUG
282 std::cerr << "unifyInexact: common type is ";
283 common->print( std::cerr );
284 std::cerr << std::endl;
285#endif
286 result = true;
287 } else {
288#ifdef DEBUG
289 std::cerr << "unifyInexact: no common type found" << std::endl;
290#endif
291 result = false;
292 } // if
293 } else {
294 if ( tq1 != tq2 ) {
295 if ( ( tq1 > tq2 || widen.first ) && ( tq2 > tq1 || widen.second ) ) {
296 common = type1->clone();
297 common->get_qualifiers() = tq1 | tq2;
298 result = true;
299 } else {
300 result = false;
301 } // if
302 } else {
303 common = type1->clone();
304 common->get_qualifiers() = tq1 | tq2;
305 result = true;
306 } // if
307 } // if
308 type1->get_qualifiers() = tq1;
309 type2->get_qualifiers() = tq2;
310 return result;
311 }
312
313 Unify_old::Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer )
314 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widen( widen ), indexer( indexer ) {
315 }
316
317 void Unify_old::postvisit( __attribute__((unused)) VoidType *voidType) {
318 result = dynamic_cast< VoidType* >( type2 );
319 }
320
321 void Unify_old::postvisit(BasicType *basicType) {
322 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
323 result = basicType->get_kind() == otherBasic->get_kind();
324 } // if
325 }
326
327 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
328/// std::cerr << "assertion set is" << std::endl;
329/// printAssertionSet( assertions, std::cerr, 8 );
330/// std::cerr << "looking for ";
331/// assert->print( std::cerr );
332/// std::cerr << std::endl;
333 AssertionSet::iterator i = assertions.find( assert );
334 if ( i != assertions.end() ) {
335/// std::cerr << "found it!" << std::endl;
336 i->second.isUsed = true;
337 } // if
338 }
339
340 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
341 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
342 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
343 markAssertionSet( assertion1, *assert );
344 markAssertionSet( assertion2, *assert );
345 } // for
346 } // for
347 }
348
349 void Unify_old::postvisit(PointerType *pointerType) {
350 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
351 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
352 markAssertions( haveAssertions, needAssertions, pointerType );
353 markAssertions( haveAssertions, needAssertions, otherPointer );
354 } // if
355 }
356
357 void Unify_old::postvisit(ReferenceType *refType) {
358 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
359 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
360 markAssertions( haveAssertions, needAssertions, refType );
361 markAssertions( haveAssertions, needAssertions, otherRef );
362 } // if
363 }
364
365 void Unify_old::postvisit(ArrayType *arrayType) {
366 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
367 // to unify, array types must both be VLA or both not VLA
368 // and must both have a dimension expression or not have a dimension
369 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
370
371 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
372 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
373 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
374 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
375 // see C11 Reference Manual 6.7.6.2.6
376 // two array types with size specifiers that are integer constant expressions are
377 // compatible if both size specifiers have the same constant value
378 if ( ce1 && ce2 ) {
379 Constant * c1 = ce1->get_constant();
380 Constant * c2 = ce2->get_constant();
381
382 if ( c1->get_value() != c2->get_value() ) {
383 // does not unify if the dimension is different
384 return;
385 }
386 }
387 }
388
389 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
390 } // if
391 }
392
393 template< typename Iterator, typename Func >
394 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
395 std::list< Type * > types;
396 for ( ; begin != end; ++begin ) {
397 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
398 flatten( toType( *begin ), back_inserter( types ) );
399 }
400 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
401 }
402
403 template< typename Iterator1, typename Iterator2 >
404 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
405 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
406 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
407 Type * t1 = (*list1Begin)->get_type();
408 Type * t2 = (*list2Begin)->get_type();
409 bool isTtype1 = Tuples::isTtype( t1 );
410 bool isTtype2 = Tuples::isTtype( t2 );
411 // xxx - assumes ttype must be last parameter
412 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
413 if ( isTtype1 && ! isTtype2 ) {
414 // combine all of the things in list2, then unify
415 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
416 } else if ( isTtype2 && ! isTtype1 ) {
417 // combine all of the things in list1, then unify
418 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
419 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
420 return false;
421 } // if
422 } // for
423 // 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
424 if ( list1Begin != list1End ) {
425 // try unifying empty tuple type with ttype
426 Type * t1 = (*list1Begin)->get_type();
427 if ( Tuples::isTtype( t1 ) ) {
428 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
429 } else return false;
430 } else if ( list2Begin != list2End ) {
431 // try unifying empty tuple type with ttype
432 Type * t2 = (*list2Begin)->get_type();
433 if ( Tuples::isTtype( t2 ) ) {
434 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
435 } else return false;
436 } else {
437 return true;
438 } // if
439 }
440
441 /// Finds ttypes and replaces them with their expansion, if known.
442 /// This needs to be done so that satisfying ttype assertions is easier.
443 /// If this isn't done then argument lists can have wildly different
444 /// size and structure, when they should be compatible.
445 struct TtypeExpander_old : public WithShortCircuiting {
446 TypeEnvironment & tenv;
447 TtypeExpander_old( TypeEnvironment & tenv ) : tenv( tenv ) {}
448 void premutate( TypeInstType * ) { visit_children = false; }
449 Type * postmutate( TypeInstType * typeInst ) {
450 if ( const EqvClass *eqvClass = tenv.lookup( typeInst->get_name() ) ) {
451 // expand ttype parameter into its actual type
452 if ( eqvClass->data.kind == TypeDecl::Ttype && eqvClass->type ) {
453 delete typeInst;
454 return eqvClass->type->clone();
455 }
456 }
457 return typeInst;
458 }
459 };
460
461 /// flattens a list of declarations, so that each tuple type has a single declaration.
462 /// makes use of TtypeExpander to ensure ttypes are flat as well.
463 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
464 dst.clear();
465 for ( DeclarationWithType * dcl : src ) {
466 PassVisitor<TtypeExpander_old> expander( env );
467 dcl->acceptMutator( expander );
468 std::list< Type * > types;
469 flatten( dcl->get_type(), back_inserter( types ) );
470 for ( Type * t : types ) {
471 // 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.
472 // 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.
473 t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic);
474
475 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
476 }
477 delete dcl;
478 }
479 }
480
481 void Unify_old::postvisit(FunctionType *functionType) {
482 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
483 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
484 // flatten the parameter lists for both functions so that tuple structure
485 // doesn't affect unification. Must be a clone so that the types don't change.
486 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
487 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
488 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
489 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
490
491 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
492 if (
493 (flatFunc->parameters.size() == flatOther->parameters.size() &&
494 flatFunc->returnVals.size() == flatOther->returnVals.size())
495 || flatFunc->isTtype()
496 || flatOther->isTtype()
497 ) {
498 if ( unifyDeclList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
499 if ( unifyDeclList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->returnVals.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
500
501 // the original types must be used in mark assertions, since pointer comparisons are used
502 markAssertions( haveAssertions, needAssertions, functionType );
503 markAssertions( haveAssertions, needAssertions, otherFunction );
504
505 result = true;
506 } // if
507 } // if
508 } // if
509 } // if
510 }
511
512 template< typename RefType >
513 void Unify_old::handleRefType( RefType *inst, Type *other ) {
514 // check that other type is compatible and named the same
515 RefType *otherStruct = dynamic_cast< RefType* >( other );
516 result = otherStruct && inst->name == otherStruct->name;
517 }
518
519 template< typename RefType >
520 void Unify_old::handleGenericRefType( RefType *inst, Type *other ) {
521 // Check that other type is compatible and named the same
522 handleRefType( inst, other );
523 if ( ! result ) return;
524 // Check that parameters of types unify, if any
525 std::list< Expression* > params = inst->parameters;
526 std::list< Expression* > otherParams = ((RefType*)other)->parameters;
527
528 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
529 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
530 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
531 assertf(param, "Aggregate parameters should be type expressions");
532 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
533 assertf(otherParam, "Aggregate parameters should be type expressions");
534
535 Type* paramTy = param->get_type();
536 Type* otherParamTy = otherParam->get_type();
537
538 bool tupleParam = Tuples::isTtype( paramTy );
539 bool otherTupleParam = Tuples::isTtype( otherParamTy );
540
541 if ( tupleParam && otherTupleParam ) {
542 ++it; ++jt; // skip ttype parameters for break
543 } else if ( tupleParam ) {
544 // bundle other parameters into tuple to match
545 std::list< Type * > binderTypes;
546
547 do {
548 binderTypes.push_back( otherParam->get_type()->clone() );
549 ++jt;
550
551 if ( jt == otherParams.end() ) break;
552
553 otherParam = dynamic_cast< TypeExpr* >(*jt);
554 assertf(otherParam, "Aggregate parameters should be type expressions");
555 } while (true);
556
557 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
558 ++it; // skip ttype parameter for break
559 } else if ( otherTupleParam ) {
560 // bundle parameters into tuple to match other
561 std::list< Type * > binderTypes;
562
563 do {
564 binderTypes.push_back( param->get_type()->clone() );
565 ++it;
566
567 if ( it == params.end() ) break;
568
569 param = dynamic_cast< TypeExpr* >(*it);
570 assertf(param, "Aggregate parameters should be type expressions");
571 } while (true);
572
573 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
574 ++jt; // skip ttype parameter for break
575 }
576
577 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
578 result = false;
579 return;
580 }
581
582 // ttype parameter should be last
583 if ( tupleParam || otherTupleParam ) break;
584 }
585 result = ( it == params.end() && jt == otherParams.end() );
586 }
587
588 void Unify_old::postvisit(StructInstType *structInst) {
589 handleGenericRefType( structInst, type2 );
590 }
591
592 void Unify_old::postvisit(UnionInstType *unionInst) {
593 handleGenericRefType( unionInst, type2 );
594 }
595
596 void Unify_old::postvisit(EnumInstType *enumInst) {
597 handleRefType( enumInst, type2 );
598 }
599
600 void Unify_old::postvisit(TraitInstType *contextInst) {
601 handleRefType( contextInst, type2 );
602 }
603
604 void Unify_old::postvisit(TypeInstType *typeInst) {
605 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
606 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
607 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
608 result = true;
609/// } else {
610/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
611/// if ( nt ) {
612/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
613/// assert( type );
614/// if ( type->get_base() ) {
615/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
616/// }
617/// }
618 } // if
619 }
620
621 template< typename Iterator1, typename Iterator2 >
622 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
623 auto get_type = [](Type * t) { return t; };
624 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
625 Type * t1 = *list1Begin;
626 Type * t2 = *list2Begin;
627 bool isTtype1 = Tuples::isTtype( t1 );
628 bool isTtype2 = Tuples::isTtype( t2 );
629 // xxx - assumes ttype must be last parameter
630 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
631 if ( isTtype1 && ! isTtype2 ) {
632 // combine all of the things in list2, then unify
633 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
634 } else if ( isTtype2 && ! isTtype1 ) {
635 // combine all of the things in list1, then unify
636 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
637 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
638 return false;
639 } // if
640
641 } // for
642 if ( list1Begin != list1End ) {
643 // try unifying empty tuple type with ttype
644 Type * t1 = *list1Begin;
645 if ( Tuples::isTtype( t1 ) ) {
646 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
647 } else return false;
648 } else if ( list2Begin != list2End ) {
649 // try unifying empty tuple type with ttype
650 Type * t2 = *list2Begin;
651 if ( Tuples::isTtype( t2 ) ) {
652 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
653 } else return false;
654 } else {
655 return true;
656 } // if
657 }
658
659 void Unify_old::postvisit(TupleType *tupleType) {
660 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
661 std::unique_ptr<TupleType> flat1( tupleType->clone() );
662 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
663 std::list<Type *> types1, types2;
664
665 PassVisitor<TtypeExpander_old> expander( env );
666 flat1->acceptMutator( expander );
667 flat2->acceptMutator( expander );
668
669 flatten( flat1.get(), back_inserter( types1 ) );
670 flatten( flat2.get(), back_inserter( types2 ) );
671
672 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
673 } // if
674 }
675
676 void Unify_old::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) {
677 result = dynamic_cast< VarArgsType* >( type2 );
678 }
679
680 void Unify_old::postvisit( __attribute__((unused)) ZeroType *zeroType ) {
681 result = dynamic_cast< ZeroType* >( type2 );
682 }
683
684 void Unify_old::postvisit( __attribute__((unused)) OneType *oneType ) {
685 result = dynamic_cast< OneType* >( type2 );
686 }
687
688 Type * extractResultType( FunctionType * function ) {
689 if ( function->get_returnVals().size() == 0 ) {
690 return new VoidType( Type::Qualifiers() );
691 } else if ( function->get_returnVals().size() == 1 ) {
692 return function->get_returnVals().front()->get_type()->clone();
693 } else {
694 std::list< Type * > types;
695 for ( DeclarationWithType * decl : function->get_returnVals() ) {
696 types.push_back( decl->get_type()->clone() );
697 } // for
698 return new TupleType( Type::Qualifiers(), types );
699 }
700 }
701
702 class Unify_new final : public ast::WithShortCircuiting {
703 const ast::Type * type2;
704 ast::TypeEnvironment & tenv;
705 ast::AssertionSet & need;
706 ast::AssertionSet & have;
707 const ast::OpenVarSet & open;
708 WidenMode widen;
709 const ast::SymbolTable & symtab;
710 public:
711 bool result;
712
713 Unify_new(
714 const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need,
715 ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen,
716 const ast::SymbolTable & symtab )
717 : type2(type2), tenv(env), need(need), have(have), open(open), widen(widen),
718 symtab(symtab), result(false) {}
719
720 void previsit( const ast::Node * ) { visit_children = false; }
721
722 void postvisit( const ast::VoidType * ) {
723 result = dynamic_cast< const ast::VoidType * >( type2 );
724 }
725
726 void postvisit( const ast::BasicType * basic ) {
727 if ( auto basic2 = dynamic_cast< const ast::BasicType * >( type2 ) ) {
728 result = basic->kind == basic2->kind;
729 }
730 }
731
732 void postvisit( const ast::PointerType * pointer ) {
733 if ( auto pointer2 = dynamic_cast< const ast::PointerType * >( type2 ) ) {
734 result = unifyExact(
735 pointer->base, pointer2->base, tenv, need, have, open,
736 noWiden(), symtab );
737 }
738 }
739
740 void postvisit( const ast::ArrayType * array ) {
741 auto array2 = dynamic_cast< const ast::ArrayType * >( type2 );
742 if ( ! array2 ) return;
743
744 // to unify, array types must both be VLA or both not VLA and both must have a
745 // dimension expression or not have a dimension
746 if ( array->isVarLen != array2->isVarLen ) return;
747 if ( ! array->isVarLen && ! array2->isVarLen
748 && array->dimension && array2->dimension ) {
749 auto ce1 = array->dimension.as< ast::ConstantExpr >();
750 auto ce2 = array2->dimension.as< ast::ConstantExpr >();
751
752 // see C11 Reference Manual 6.7.6.2.6
753 // two array types with size specifiers that are integer constant expressions are
754 // compatible if both size specifiers have the same constant value
755 if ( ce1 && ce2 && ce1->intValue() != ce2->intValue() ) return;
756 }
757
758 result = unifyExact(
759 array->base, array2->base, tenv, need, have, open, noWiden(),
760 symtab );
761 }
762
763 void postvisit( const ast::ReferenceType * ref ) {
764 if ( auto ref2 = dynamic_cast< const ast::ReferenceType * >( type2 ) ) {
765 result = unifyExact(
766 ref->base, ref2->base, tenv, need, have, open, noWiden(),
767 symtab );
768 }
769 }
770
771 private:
772 /// Replaces ttype variables with their bound types.
773 /// If this isn't done when satifying ttype assertions, then argument lists can have
774 /// different size and structure when they should be compatible.
775 struct TtypeExpander_new : public ast::WithShortCircuiting {
776 ast::TypeEnvironment & tenv;
777
778 TtypeExpander_new( ast::TypeEnvironment & env ) : tenv( env ) {}
779
780 const ast::Type * postvisit( const ast::TypeInstType * typeInst ) {
781 if ( const ast::EqvClass * clz = tenv.lookup( typeInst->name ) ) {
782 // expand ttype parameter into its actual type
783 if ( clz->data.kind == ast::TypeVar::Ttype && clz->bound ) {
784 return clz->bound;
785 }
786 }
787 return typeInst;
788 }
789 };
790
791 /// returns flattened version of `src`
792 static std::vector< ast::ptr< ast::DeclWithType > > flattenList(
793 const std::vector< ast::ptr< ast::DeclWithType > > & src, ast::TypeEnvironment & env
794 ) {
795 std::vector< ast::ptr< ast::DeclWithType > > dst;
796 dst.reserve( src.size() );
797 for ( const ast::DeclWithType * d : src ) {
798 ast::Pass<TtypeExpander_new> expander{ env };
799 d = d->accept( expander );
800 auto types = flatten( d->get_type() );
801 for ( ast::ptr< ast::Type > & t : types ) {
802 // outermost const, volatile, _Atomic qualifiers in parameters should not play
803 // a role in the unification of function types, since they do not determine
804 // whether a function is callable.
805 // NOTE: **must** consider at least mutex qualifier, since functions can be
806 // overloaded on outermost mutex and a mutex function has different
807 // requirements than a non-mutex function
808 remove_qualifiers( t, ast::CV::Const | ast::CV::Volatile | ast::CV::Atomic );
809 dst.emplace_back( new ast::ObjectDecl{ d->location, "", t } );
810 }
811 }
812 return dst;
813 }
814
815 /// Creates a tuple type based on a list of DeclWithType
816 template< typename Iter >
817 static ast::ptr< ast::Type > tupleFromDecls( Iter crnt, Iter end ) {
818 std::vector< ast::ptr< ast::Type > > types;
819 while ( crnt != end ) {
820 // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure
821 // that this results in a flat tuple
822 flatten( (*crnt)->get_type(), types );
823
824 ++crnt;
825 }
826
827 return { new ast::TupleType{ std::move(types) } };
828 }
829
830 template< typename Iter >
831 static bool unifyDeclList(
832 Iter crnt1, Iter end1, Iter crnt2, Iter end2, ast::TypeEnvironment & env,
833 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
834 const ast::SymbolTable & symtab
835 ) {
836 while ( crnt1 != end1 && crnt2 != end2 ) {
837 const ast::Type * t1 = (*crnt1)->get_type();
838 const ast::Type * t2 = (*crnt2)->get_type();
839 bool isTuple1 = Tuples::isTtype( t1 );
840 bool isTuple2 = Tuples::isTtype( t2 );
841
842 // assumes here that ttype *must* be last parameter
843 if ( isTuple1 && ! isTuple2 ) {
844 // combine remainder of list2, then unify
845 return unifyExact(
846 t1, tupleFromDecls( crnt2, end2 ), env, need, have, open,
847 noWiden(), symtab );
848 } else if ( ! isTuple1 && isTuple2 ) {
849 // combine remainder of list1, then unify
850 return unifyExact(
851 tupleFromDecls( crnt1, end1 ), t2, env, need, have, open,
852 noWiden(), symtab );
853 }
854
855 if ( ! unifyExact(
856 t1, t2, env, need, have, open, noWiden(), symtab )
857 ) return false;
858
859 ++crnt1; ++crnt2;
860 }
861
862 // May get to the end of one argument list before the other. This is only okay if the
863 // other is a ttype
864 if ( crnt1 != end1 ) {
865 // try unifying empty tuple with ttype
866 const ast::Type * t1 = (*crnt1)->get_type();
867 if ( ! Tuples::isTtype( t1 ) ) return false;
868 return unifyExact(
869 t1, tupleFromDecls( crnt2, end2 ), env, need, have, open,
870 noWiden(), symtab );
871 } else if ( crnt2 != end2 ) {
872 // try unifying empty tuple with ttype
873 const ast::Type * t2 = (*crnt2)->get_type();
874 if ( ! Tuples::isTtype( t2 ) ) return false;
875 return unifyExact(
876 tupleFromDecls( crnt1, end1 ), t2, env, need, have, open,
877 noWiden(), symtab );
878 }
879
880 return true;
881 }
882
883 static bool unifyDeclList(
884 const std::vector< ast::ptr< ast::DeclWithType > > & list1,
885 const std::vector< ast::ptr< ast::DeclWithType > > & list2,
886 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
887 const ast::OpenVarSet & open, const ast::SymbolTable & symtab
888 ) {
889 return unifyDeclList(
890 list1.begin(), list1.end(), list2.begin(), list2.end(), env, need, have, open,
891 symtab );
892 }
893
894 static void markAssertionSet( ast::AssertionSet & assns, const ast::DeclWithType * assn ) {
895 auto i = assns.find( assn );
896 if ( i != assns.end() ) {
897 i->second.isUsed = true;
898 }
899 }
900
901 /// mark all assertions in `type` used in both `assn1` and `assn2`
902 static void markAssertions(
903 ast::AssertionSet & assn1, ast::AssertionSet & assn2,
904 const ast::ParameterizedType * type
905 ) {
906 for ( const auto & tyvar : type->forall ) {
907 for ( const ast::DeclWithType * assert : tyvar->assertions ) {
908 markAssertionSet( assn1, assert );
909 markAssertionSet( assn2, assert );
910 }
911 }
912 }
913
914 public:
915 void postvisit( const ast::FunctionType * func ) {
916 auto func2 = dynamic_cast< const ast::FunctionType * >( type2 );
917 if ( ! func2 ) return;
918
919 if ( func->isVarArgs != func2->isVarArgs ) return;
920
921 // Flatten the parameter lists for both functions so that tuple structure does not
922 // affect unification. Does not actually mutate function parameters.
923 auto params = flattenList( func->params, tenv );
924 auto params2 = flattenList( func2->params, tenv );
925
926 // sizes don't have to match if ttypes are involved; need to be more precise w.r.t.
927 // where the ttype is to prevent errors
928 if (
929 ( params.size() != params2.size() || func->returns.size() != func2->returns.size() )
930 && ! func->isTtype()
931 && ! func2->isTtype()
932 ) return;
933
934 if ( ! unifyDeclList( params, params2, tenv, need, have, open, symtab ) ) return;
935 if ( ! unifyDeclList(
936 func->returns, func2->returns, tenv, need, have, open, symtab ) ) return;
937
938 markAssertions( have, need, func );
939 markAssertions( have, need, func2 );
940
941 result = true;
942 }
943
944 private:
945 template< typename RefType >
946 const RefType * handleRefType( const RefType * inst, const ast::Type * other ) {
947 // check that the other type is compatible and named the same
948 auto otherInst = dynamic_cast< const RefType * >( other );
949 result = otherInst && inst->name == otherInst->name;
950 return otherInst;
951 }
952
953 /// Creates a tuple type based on a list of TypeExpr
954 template< typename Iter >
955 static const ast::Type * tupleFromExprs(
956 const ast::TypeExpr * param, Iter & crnt, Iter end, ast::CV::Qualifiers qs
957 ) {
958 std::vector< ast::ptr< ast::Type > > types;
959 do {
960 types.emplace_back( param->type );
961
962 ++crnt;
963 if ( crnt == end ) break;
964 param = strict_dynamic_cast< const ast::TypeExpr * >( crnt->get() );
965 } while(true);
966
967 return new ast::TupleType{ std::move(types), qs };
968 }
969
970 template< typename RefType >
971 void handleGenericRefType( const RefType * inst, const ast::Type * other ) {
972 // check that other type is compatible and named the same
973 const RefType * inst2 = handleRefType( inst, other );
974 if ( ! inst2 ) return;
975
976 // check that parameters of types unify, if any
977 const std::vector< ast::ptr< ast::Expr > > & params = inst->params;
978 const std::vector< ast::ptr< ast::Expr > > & params2 = inst2->params;
979
980 auto it = params.begin();
981 auto jt = params2.begin();
982 for ( ; it != params.end() && jt != params2.end(); ++it, ++jt ) {
983 auto param = strict_dynamic_cast< const ast::TypeExpr * >( it->get() );
984 auto param2 = strict_dynamic_cast< const ast::TypeExpr * >( jt->get() );
985
986 ast::ptr< ast::Type > pty = param->type;
987 ast::ptr< ast::Type > pty2 = param2->type;
988
989 bool isTuple = Tuples::isTtype( pty );
990 bool isTuple2 = Tuples::isTtype( pty2 );
991
992 if ( isTuple && isTuple2 ) {
993 ++it; ++jt; // skip ttype parameters before break
994 } else if ( isTuple ) {
995 // bundle remaining params into tuple
996 pty2 = tupleFromExprs( param2, jt, params2.end(), pty->qualifiers );
997 ++it; // skip ttype parameter for break
998 } else if ( isTuple2 ) {
999 // bundle remaining params into tuple
1000 pty = tupleFromExprs( param, it, params.end(), pty2->qualifiers );
1001 ++jt; // skip ttype parameter for break
1002 }
1003
1004 if ( ! unifyExact(
1005 pty, pty2, tenv, need, have, open, noWiden(), symtab ) ) {
1006 result = false;
1007 return;
1008 }
1009
1010 // ttype parameter should be last
1011 if ( isTuple || isTuple2 ) break;
1012 }
1013 result = it == params.end() && jt == params2.end();
1014 }
1015
1016 public:
1017 void postvisit( const ast::StructInstType * aggrType ) {
1018 handleGenericRefType( aggrType, type2 );
1019 }
1020
1021 void postvisit( const ast::UnionInstType * aggrType ) {
1022 handleGenericRefType( aggrType, type2 );
1023 }
1024
1025 void postvisit( const ast::EnumInstType * aggrType ) {
1026 handleRefType( aggrType, type2 );
1027 }
1028
1029 void postvisit( const ast::TraitInstType * aggrType ) {
1030 handleRefType( aggrType, type2 );
1031 }
1032
1033 void postvisit( const ast::TypeInstType * typeInst ) {
1034 assert( open.find( typeInst->name ) == open.end() );
1035 handleRefType( typeInst, type2 );
1036 }
1037
1038 private:
1039 /// Creates a tuple type based on a list of Type
1040 static ast::ptr< ast::Type > tupleFromTypes(
1041 const std::vector< ast::ptr< ast::Type > > & tys
1042 ) {
1043 std::vector< ast::ptr< ast::Type > > out;
1044 for ( const ast::Type * ty : tys ) {
1045 // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure
1046 // that this results in a flat tuple
1047 flatten( ty, out );
1048 }
1049
1050 return { new ast::TupleType{ std::move(out) } };
1051 }
1052
1053 static bool unifyList(
1054 const std::vector< ast::ptr< ast::Type > > & list1,
1055 const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env,
1056 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1057 const ast::SymbolTable & symtab
1058 ) {
1059 auto crnt1 = list1.begin();
1060 auto crnt2 = list2.begin();
1061 while ( crnt1 != list1.end() && crnt2 != list2.end() ) {
1062 const ast::Type * t1 = *crnt1;
1063 const ast::Type * t2 = *crnt2;
1064 bool isTuple1 = Tuples::isTtype( t1 );
1065 bool isTuple2 = Tuples::isTtype( t2 );
1066
1067 // assumes ttype must be last parameter
1068 if ( isTuple1 && ! isTuple2 ) {
1069 // combine entirety of list2, then unify
1070 return unifyExact(
1071 t1, tupleFromTypes( list2 ), env, need, have, open,
1072 noWiden(), symtab );
1073 } else if ( ! isTuple1 && isTuple2 ) {
1074 // combine entirety of list1, then unify
1075 return unifyExact(
1076 tupleFromTypes( list1 ), t2, env, need, have, open,
1077 noWiden(), symtab );
1078 }
1079
1080 if ( ! unifyExact(
1081 t1, t2, env, need, have, open, noWiden(), symtab )
1082 ) return false;
1083
1084 ++crnt1; ++crnt2;
1085 }
1086
1087 if ( crnt1 != list1.end() ) {
1088 // try unifying empty tuple type with ttype
1089 const ast::Type * t1 = *crnt1;
1090 if ( ! Tuples::isTtype( t1 ) ) return false;
1091 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1092 // from Rob's code
1093 return unifyExact(
1094 t1, tupleFromTypes( list2 ), env, need, have, open,
1095 noWiden(), symtab );
1096 } else if ( crnt2 != list2.end() ) {
1097 // try unifying empty tuple with ttype
1098 const ast::Type * t2 = *crnt2;
1099 if ( ! Tuples::isTtype( t2 ) ) 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 tupleFromTypes( list1 ), t2, env, need, have, open,
1104 noWiden(), symtab );
1105 }
1106
1107 return true;
1108 }
1109
1110 public:
1111 void postvisit( const ast::TupleType * tuple ) {
1112 auto tuple2 = dynamic_cast< const ast::TupleType * >( type2 );
1113 if ( ! tuple2 ) return;
1114
1115 ast::Pass<TtypeExpander_new> expander{ tenv };
1116 const ast::Type * flat = tuple->accept( expander );
1117 const ast::Type * flat2 = tuple2->accept( expander );
1118
1119 auto types = flatten( flat );
1120 auto types2 = flatten( flat2 );
1121
1122 result = unifyList( types, types2, tenv, need, have, open, symtab );
1123 }
1124
1125 void postvisit( const ast::VarArgsType * ) {
1126 result = dynamic_cast< const ast::VarArgsType * >( type2 );
1127 }
1128
1129 void postvisit( const ast::ZeroType * ) {
1130 result = dynamic_cast< const ast::ZeroType * >( type2 );
1131 }
1132
1133 void postvisit( const ast::OneType * ) {
1134 result = dynamic_cast< const ast::OneType * >( type2 );
1135 }
1136
1137 private:
1138 template< typename RefType > void handleRefType( RefType *inst, Type *other );
1139 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
1140 };
1141
1142 bool unify(
1143 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1144 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1145 ast::OpenVarSet & open, const ast::SymbolTable & symtab
1146 ) {
1147 ast::ptr<ast::Type> common;
1148 return unify( type1, type2, env, need, have, open, symtab, common );
1149 }
1150
1151 bool unify(
1152 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1153 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1154 ast::OpenVarSet & open, const ast::SymbolTable & symtab, ast::ptr<ast::Type> & common
1155 ) {
1156 ast::OpenVarSet closed;
1157 findOpenVars( type1, open, closed, need, have, FirstClosed );
1158 findOpenVars( type2, open, closed, need, have, FirstOpen );
1159 return unifyInexact(
1160 type1, type2, env, need, have, open, WidenMode{ true, true }, symtab, common );
1161 }
1162
1163 bool unifyExact(
1164 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
1165 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1166 WidenMode widen, const ast::SymbolTable & symtab
1167 ) {
1168 if ( type1->qualifiers != type2->qualifiers ) return false;
1169
1170 auto var1 = dynamic_cast< const ast::TypeInstType * >( type1 );
1171 auto var2 = dynamic_cast< const ast::TypeInstType * >( type2 );
1172 ast::OpenVarSet::const_iterator
1173 entry1 = var1 ? open.find( var1->name ) : open.end(),
1174 entry2 = var2 ? open.find( var2->name ) : open.end();
1175 bool isopen1 = entry1 != open.end();
1176 bool isopen2 = entry2 != open.end();
1177
1178 if ( isopen1 && isopen2 ) {
1179 if ( entry1->second.kind != entry2->second.kind ) return false;
1180 return env.bindVarToVar(
1181 var1, var2, ast::TypeDecl::Data{ entry1->second, entry2->second }, need, have,
1182 open, widen, symtab );
1183 } else if ( isopen1 ) {
1184 return env.bindVar( var1, type2, entry1->second, need, have, open, widen, symtab );
1185 } else if ( isopen2 ) {
1186 return env.bindVar( var2, type1, entry2->second, need, have, open, widen, symtab );
1187 } else {
1188 ast::Pass<Unify_new> comparator{ type2, env, need, have, open, widen, symtab };
1189 type1->accept( comparator );
1190 return comparator.pass.result;
1191 }
1192 }
1193
1194 bool unifyInexact(
1195 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1196 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1197 const ast::OpenVarSet & open, WidenMode widen, const ast::SymbolTable & symtab,
1198 ast::ptr<ast::Type> & common
1199 ) {
1200 ast::CV::Qualifiers q1 = type1->qualifiers, q2 = type2->qualifiers;
1201
1202 // force t1 and t2 to be cloned if their qualifiers must be stripped, so that type1 and
1203 // type2 are left unchanged; calling convention forces type{1,2}->strong_ref >= 1
1204 ast::ptr<ast::Type> t1{ type1 }, t2{ type2 };
1205 reset_qualifiers( t1 );
1206 reset_qualifiers( t2 );
1207
1208 if ( unifyExact( t1, t2, env, need, have, open, widen, symtab ) ) {
1209 t1 = nullptr; t2 = nullptr; // release t1, t2 to avoid spurious clones
1210
1211 // if exact unification on unqualified types, try to merge qualifiers
1212 if ( q1 == q2 || ( ( q1 > q2 || widen.first ) && ( q2 > q1 || widen.second ) ) ) {
1213 common = type1;
1214 reset_qualifiers( common, q1 | q2 );
1215 return true;
1216 } else {
1217 return false;
1218 }
1219
1220 } else if (( common = commonType( t1, t2, widen, symtab, env, open ) )) {
1221 t1 = nullptr; t2 = nullptr; // release t1, t2 to avoid spurious clones
1222
1223 // no exact unification, but common type
1224 reset_qualifiers( common, q1 | q2 );
1225 return true;
1226 } else {
1227 return false;
1228 }
1229 }
1230
1231 ast::ptr<ast::Type> extractResultType( const ast::FunctionType * func ) {
1232 if ( func->returns.empty() ) return new ast::VoidType{};
1233 if ( func->returns.size() == 1 ) return func->returns[0]->get_type();
1234
1235 std::vector<ast::ptr<ast::Type>> tys;
1236 for ( const ast::DeclWithType * decl : func->returns ) {
1237 tys.emplace_back( decl->get_type() );
1238 }
1239 return new ast::TupleType{ std::move(tys) };
1240 }
1241} // namespace ResolvExpr
1242
1243// Local Variables: //
1244// tab-width: 4 //
1245// mode: c++ //
1246// compile-command: "make install" //
1247// End: //
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