source: src/ResolvExpr/Unify.cc@ bc4bea8

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 bc4bea8 was f474e91, checked in by Aaron Moss <a3moss@…>, 6 years ago

Port unification calculations to new AST
  • 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 : 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, WidenMode{ false, false }, 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 clear_qualifiers( newFirst );
176 clear_qualifiers( newSecond );
177
178 return unifyExact(
179 newFirst, newSecond, newEnv, need, have, open, WidenMode{ false, false }, 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 : 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 previsit( const ast::VoidType * ) {
723 visit_children = false;
724 result = dynamic_cast< const ast::VoidType * >( type2 );
725 }
726
727 void previsit( const ast::BasicType * basic ) {
728 visit_children = false;
729 if ( auto basic2 = dynamic_cast< const ast::BasicType * >( type2 ) ) {
730 result = basic->kind == basic2->kind;
731 }
732 }
733
734 void previsit( const ast::PointerType * pointer ) {
735 visit_children = false;
736 if ( auto pointer2 = dynamic_cast< const ast::PointerType * >( type2 ) ) {
737 result = unifyExact(
738 pointer->base, pointer2->base, tenv, need, have, open,
739 WidenMode{ false, false }, symtab );
740 }
741 }
742
743 void previsit( const ast::ArrayType * array ) {
744 visit_children = false;
745 auto array2 = dynamic_cast< const ast::ArrayType * >( type2 );
746 if ( ! array2 ) return;
747
748 // to unify, array types must both be VLA or both not VLA and both must have a
749 // dimension expression or not have a dimension
750 if ( array->isVarLen != array2->isVarLen ) return;
751 if ( ! array->isVarLen && ! array2->isVarLen
752 && array->dimension && array2->dimension ) {
753 auto ce1 = array->dimension.as< ast::ConstantExpr >();
754 auto ce2 = array2->dimension.as< ast::ConstantExpr >();
755
756 // see C11 Reference Manual 6.7.6.2.6
757 // two array types with size specifiers that are integer constant expressions are
758 // compatible if both size specifiers have the same constant value
759 if ( ce1 && ce2 && ce1->intValue() != ce2->intValue() ) return;
760 }
761
762 result = unifyExact(
763 array->base, array2->base, tenv, need, have, open, WidenMode{ false, false },
764 symtab );
765 }
766
767 void previsit( const ast::ReferenceType * ref ) {
768 visit_children = false;
769 if ( auto ref2 = dynamic_cast< const ast::ReferenceType * >( type2 ) ) {
770 result = unifyExact(
771 ref->base, ref2->base, tenv, need, have, open, WidenMode{ false, false },
772 symtab );
773 }
774 }
775
776 private:
777 /// Replaces ttype variables with their bound types.
778 /// If this isn't done when satifying ttype assertions, then argument lists can have
779 /// different size and structure when they should be compatible.
780 struct TtypeExpander_new : public ast::WithShortCircuiting {
781 ast::TypeEnvironment & tenv;
782
783 TtypeExpander_new( ast::TypeEnvironment & env ) : tenv( env ) {}
784
785 const ast::Type * postmutate( const ast::TypeInstType * typeInst ) {
786 if ( const ast::EqvClass * clz = tenv.lookup( typeInst->name ) ) {
787 // expand ttype parameter into its actual type
788 if ( clz->data.kind == ast::TypeVar::Ttype && clz->bound ) {
789 return clz->bound;
790 }
791 }
792 return typeInst;
793 }
794 };
795
796 /// returns flattened version of `src`
797 static std::vector< ast::ptr< ast::DeclWithType > > flattenList(
798 const std::vector< ast::ptr< ast::DeclWithType > > & src, ast::TypeEnvironment & env
799 ) {
800 std::vector< ast::ptr< ast::DeclWithType > > dst;
801 dst.reserve( src.size() );
802 for ( const ast::DeclWithType * d : src ) {
803 ast::Pass<TtypeExpander_new> expander{ env };
804 d = d->accept( expander );
805 auto types = flatten( d->get_type() );
806 for ( ast::ptr< ast::Type > & t : types ) {
807 // outermost const, volatile, _Atomic qualifiers in parameters should not play
808 // a role in the unification of function types, since they do not determine
809 // whether a function is callable.
810 // NOTE: **must** consider at least mutex qualifier, since functions can be
811 // overloaded on outermost mutex and a mutex function has different
812 // requirements than a non-mutex function
813 t.get_and_mutate()->qualifiers
814 -= ast::CV::Const | ast::CV::Volatile | ast::CV::Atomic;
815 dst.emplace_back( new ast::ObjectDecl{ d->location, "", t } );
816 }
817 }
818 return dst;
819 }
820
821 /// Creates a tuple type based on a list of DeclWithType
822 template< typename Iter >
823 static ast::ptr< ast::Type > tupleFromDecls( Iter crnt, Iter end ) {
824 std::vector< ast::ptr< ast::Type > > types;
825 while ( crnt != end ) {
826 // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure
827 // that this results in a flat tuple
828 flatten( (*crnt)->get_type(), types );
829
830 ++crnt;
831 }
832
833 return { new ast::TupleType{ std::move(types) } };
834 }
835
836 template< typename Iter >
837 static bool unifyDeclList(
838 Iter crnt1, Iter end1, Iter crnt2, Iter end2, ast::TypeEnvironment & env,
839 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
840 const ast::SymbolTable & symtab
841 ) {
842 while ( crnt1 != end1 && crnt2 != end2 ) {
843 const ast::Type * t1 = (*crnt1)->get_type();
844 const ast::Type * t2 = (*crnt2)->get_type();
845 bool isTuple1 = Tuples::isTtype( t1 );
846 bool isTuple2 = Tuples::isTtype( t2 );
847
848 // assumes here that ttype *must* be last parameter
849 if ( isTuple1 && ! isTuple2 ) {
850 // combine remainder of list2, then unify
851 return unifyExact(
852 t1, tupleFromDecls( crnt2, end2 ), env, need, have, open,
853 WidenMode{ false, false }, symtab );
854 } else if ( ! isTuple1 && isTuple2 ) {
855 // combine remainder of list1, then unify
856 return unifyExact(
857 tupleFromDecls( crnt1, end1 ), t2, env, need, have, open,
858 WidenMode{ false, false }, symtab );
859 }
860
861 if ( ! unifyExact(
862 t1, t2, env, need, have, open, WidenMode{ false, false }, symtab )
863 ) return false;
864
865 ++crnt1; ++crnt2;
866 }
867
868 // May get to the end of one argument list before the other. This is only okay if the
869 // other is a ttype
870 if ( crnt1 != end1 ) {
871 // try unifying empty tuple with ttype
872 const ast::Type * t1 = (*crnt1)->get_type();
873 if ( ! Tuples::isTtype( t1 ) ) return false;
874 return unifyExact(
875 t1, tupleFromDecls( crnt2, end2 ), env, need, have, open,
876 WidenMode{ false, false }, symtab );
877 } else if ( crnt2 != end2 ) {
878 // try unifying empty tuple with ttype
879 const ast::Type * t2 = (*crnt2)->get_type();
880 if ( ! Tuples::isTtype( t2 ) ) return false;
881 return unifyExact(
882 tupleFromDecls( crnt1, end1 ), t2, env, need, have, open,
883 WidenMode{ false, false }, symtab );
884 }
885
886 return true;
887 }
888
889 static bool unifyDeclList(
890 const std::vector< ast::ptr< ast::DeclWithType > > & list1,
891 const std::vector< ast::ptr< ast::DeclWithType > > & list2,
892 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
893 const ast::OpenVarSet & open, const ast::SymbolTable & symtab
894 ) {
895 return unifyDeclList(
896 list1.begin(), list1.end(), list2.begin(), list2.end(), env, need, have, open,
897 symtab );
898 }
899
900 static void markAssertionSet( ast::AssertionSet & assns, const ast::DeclWithType * assn ) {
901 auto i = assns.find( assn );
902 if ( i != assns.end() ) {
903 i->second.isUsed = true;
904 }
905 }
906
907 /// mark all assertions in `type` used in both `assn1` and `assn2`
908 static void markAssertions(
909 ast::AssertionSet & assn1, ast::AssertionSet & assn2,
910 const ast::ParameterizedType * type
911 ) {
912 for ( const auto & tyvar : type->forall ) {
913 for ( const ast::DeclWithType * assert : tyvar->assertions ) {
914 markAssertionSet( assn1, assert );
915 markAssertionSet( assn2, assert );
916 }
917 }
918 }
919
920 public:
921 void previsit( const ast::FunctionType * func ) {
922 visit_children = false;
923 auto func2 = dynamic_cast< const ast::FunctionType * >( type2 );
924 if ( ! func2 ) return;
925
926 if ( func->isVarArgs != func2->isVarArgs ) return;
927
928 // Flatten the parameter lists for both functions so that tuple structure does not
929 // affect unification. Does not actually mutate function parameters.
930 auto params = flattenList( func->params, tenv );
931 auto params2 = flattenList( func2->params, tenv );
932
933 // sizes don't have to match if ttypes are involved; need to be more precise w.r.t.
934 // where the ttype is to prevent errors
935 if (
936 ( params.size() != params2.size() || func->returns.size() != func2->returns.size() )
937 && ! func->isTtype()
938 && ! func2->isTtype()
939 ) return;
940
941 if ( ! unifyDeclList( params, params2, tenv, need, have, open, symtab ) ) return;
942 if ( ! unifyDeclList(
943 func->returns, func2->returns, tenv, need, have, open, symtab ) ) return;
944
945 markAssertions( have, need, func );
946 markAssertions( have, need, func2 );
947
948 result = true;
949 }
950
951 private:
952 template< typename RefType >
953 const RefType * handleRefType( const RefType * inst, const ast::Type * other ) {
954 visit_children = false;
955 // check that the other type is compatible and named the same
956 auto otherInst = dynamic_cast< const RefType * >( other );
957 result = otherInst && inst->name == otherInst->name;
958 return otherInst;
959 }
960
961 /// Creates a tuple type based on a list of TypeExpr
962 template< typename Iter >
963 static const ast::Type * tupleFromExprs(
964 const ast::TypeExpr * param, Iter & crnt, Iter end, ast::CV::Qualifiers qs
965 ) {
966 std::vector< ast::ptr< ast::Type > > types;
967 do {
968 types.emplace_back( param->type );
969
970 ++crnt;
971 if ( crnt == end ) break;
972 param = strict_dynamic_cast< const ast::TypeExpr * >( crnt->get() );
973 } while(true);
974
975 return new ast::TupleType{ std::move(types), qs };
976 }
977
978 template< typename RefType >
979 void handleGenericRefType( const RefType * inst, const ast::Type * other ) {
980 // check that other type is compatible and named the same
981 const RefType * inst2 = handleRefType( inst, other );
982 if ( ! inst2 ) return;
983
984 // check that parameters of types unify, if any
985 const std::vector< ast::ptr< ast::Expr > > & params = inst->params;
986 const std::vector< ast::ptr< ast::Expr > > & params2 = inst2->params;
987
988 auto it = params.begin();
989 auto jt = params2.begin();
990 for ( ; it != params.end() && jt != params2.end(); ++it, ++jt ) {
991 auto param = strict_dynamic_cast< const ast::TypeExpr * >( it->get() );
992 auto param2 = strict_dynamic_cast< const ast::TypeExpr * >( jt->get() );
993
994 ast::ptr< ast::Type > pty = param->type;
995 ast::ptr< ast::Type > pty2 = param2->type;
996
997 bool isTuple = Tuples::isTtype( pty );
998 bool isTuple2 = Tuples::isTtype( pty2 );
999
1000 if ( isTuple && isTuple2 ) {
1001 ++it; ++jt; // skip ttype parameters before break
1002 } else if ( isTuple ) {
1003 // bundle remaining params into tuple
1004 pty2 = tupleFromExprs( param2, jt, params2.end(), pty->qualifiers );
1005 ++it; // skip ttype parameter for break
1006 } else if ( isTuple2 ) {
1007 // bundle remaining params into tuple
1008 pty = tupleFromExprs( param, it, params.end(), pty2->qualifiers );
1009 ++jt; // skip ttype parameter for break
1010 }
1011
1012 if ( ! unifyExact(
1013 pty, pty2, tenv, need, have, open, WidenMode{ false, false }, symtab ) ) {
1014 result = false;
1015 return;
1016 }
1017
1018 // ttype parameter should be last
1019 if ( isTuple || isTuple2 ) break;
1020 }
1021 result = it == params.end() && jt == params2.end();
1022 }
1023
1024 public:
1025 void previsit( const ast::StructInstType * aggrType ) {
1026 handleGenericRefType( aggrType, type2 );
1027 }
1028
1029 void previsit( const ast::UnionInstType * aggrType ) {
1030 handleGenericRefType( aggrType, type2 );
1031 }
1032
1033 void previsit( const ast::EnumInstType * aggrType ) {
1034 handleRefType( aggrType, type2 );
1035 }
1036
1037 void previsit( const ast::TraitInstType * aggrType ) {
1038 handleRefType( aggrType, type2 );
1039 }
1040
1041 void previsit( const ast::TypeInstType * typeInst ) {
1042 assert( open.find( typeInst->name ) == open.end() );
1043 handleRefType( typeInst, type2 );
1044 }
1045
1046 private:
1047 /// Creates a tuple type based on a list of Type
1048 static ast::ptr< ast::Type > tupleFromTypes(
1049 const std::vector< ast::ptr< ast::Type > > & tys
1050 ) {
1051 std::vector< ast::ptr< ast::Type > > out;
1052 for ( const ast::Type * ty : tys ) {
1053 // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure
1054 // that this results in a flat tuple
1055 flatten( ty, out );
1056 }
1057
1058 return { new ast::TupleType{ std::move(out) } };
1059 }
1060
1061 static bool unifyList(
1062 const std::vector< ast::ptr< ast::Type > > & list1,
1063 const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env,
1064 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1065 const ast::SymbolTable & symtab
1066 ) {
1067 auto crnt1 = list1.begin();
1068 auto crnt2 = list2.begin();
1069 while ( crnt1 != list1.end() && crnt2 != list2.end() ) {
1070 const ast::Type * t1 = *crnt1;
1071 const ast::Type * t2 = *crnt2;
1072 bool isTuple1 = Tuples::isTtype( t1 );
1073 bool isTuple2 = Tuples::isTtype( t2 );
1074
1075 // assumes ttype must be last parameter
1076 if ( isTuple1 && ! isTuple2 ) {
1077 // combine entirety of list2, then unify
1078 return unifyExact(
1079 t1, tupleFromTypes( list2 ), env, need, have, open,
1080 WidenMode{ false, false }, symtab );
1081 } else if ( ! isTuple1 && isTuple2 ) {
1082 // combine entirety of list1, then unify
1083 return unifyExact(
1084 tupleFromTypes( list1 ), t2, env, need, have, open,
1085 WidenMode{ false, false }, symtab );
1086 }
1087
1088 if ( ! unifyExact(
1089 t1, t2, env, need, have, open, WidenMode{ false, false }, symtab )
1090 ) return false;
1091
1092 ++crnt1; ++crnt2;
1093 }
1094
1095 if ( crnt1 != list1.end() ) {
1096 // try unifying empty tuple type with ttype
1097 const ast::Type * t1 = *crnt1;
1098 if ( ! Tuples::isTtype( t1 ) ) return false;
1099 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1100 // from Rob's code
1101 return unifyExact(
1102 t1, tupleFromTypes( list2 ), env, need, have, open,
1103 WidenMode{ false, false }, symtab );
1104 } else if ( crnt2 != list2.end() ) {
1105 // try unifying empty tuple with ttype
1106 const ast::Type * t2 = *crnt2;
1107 if ( ! Tuples::isTtype( t2 ) ) return false;
1108 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1109 // from Rob's code
1110 return unifyExact(
1111 tupleFromTypes( list1 ), t2, env, need, have, open,
1112 WidenMode{ false, false }, symtab );
1113 }
1114
1115 return true;
1116 }
1117
1118 public:
1119 void previsit( const ast::TupleType * tuple ) {
1120 visit_children = false;
1121 auto tuple2 = dynamic_cast< const ast::TupleType * >( type2 );
1122 if ( ! tuple2 ) return;
1123
1124 ast::Pass<TtypeExpander_new> expander{ tenv };
1125 const ast::Type * flat = tuple->accept( expander );
1126 const ast::Type * flat2 = tuple2->accept( expander );
1127
1128 auto types = flatten( flat );
1129 auto types2 = flatten( flat2 );
1130
1131 result = unifyList( types, types2, tenv, need, have, open, symtab );
1132 }
1133
1134 void previsit( const ast::VarArgsType * ) {
1135 visit_children = false;
1136 result = dynamic_cast< const ast::VarArgsType * >( type2 );
1137 }
1138
1139 void previsit( const ast::ZeroType * ) {
1140 visit_children = false;
1141 result = dynamic_cast< const ast::ZeroType * >( type2 );
1142 }
1143
1144 void previsit( const ast::OneType * ) {
1145 visit_children = false;
1146 result = dynamic_cast< const ast::OneType * >( type2 );
1147 }
1148
1149 private:
1150 template< typename RefType > void handleRefType( RefType *inst, Type *other );
1151 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
1152 };
1153
1154 bool unifyExact(
1155 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
1156 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1157 WidenMode widen, const ast::SymbolTable & symtab
1158 ) {
1159 if ( type1->qualifiers != type2->qualifiers ) return false;
1160
1161 auto var1 = dynamic_cast< const ast::TypeInstType * >( type1 );
1162 auto var2 = dynamic_cast< const ast::TypeInstType * >( type2 );
1163 ast::OpenVarSet::const_iterator
1164 entry1 = var1 ? open.find( var1->name ) : open.end(),
1165 entry2 = var2 ? open.find( var2->name ) : open.end();
1166 bool isopen1 = entry1 != open.end();
1167 bool isopen2 = entry2 != open.end();
1168
1169 if ( isopen1 && isopen2 ) {
1170 if ( entry1->second.kind != entry2->second.kind ) return false;
1171 return env.bindVarToVar(
1172 var1, var2, ast::TypeDecl::Data{ entry1->second, entry2->second }, need, have,
1173 open, widen, symtab );
1174 } else if ( isopen1 ) {
1175 return env.bindVar( var1, type2, entry1->second, need, have, open, widen, symtab );
1176 } else if ( isopen2 ) {
1177 return env.bindVar( var2, type1, entry2->second, need, have, open, widen, symtab );
1178 } else {
1179 ast::Pass<Unify_new> comparator{ type2, env, need, have, open, widen, symtab };
1180 type1->accept( comparator );
1181 return comparator.pass.result;
1182 }
1183 }
1184
1185 bool unifyInexact(
1186 ast::ptr<ast::Type> & type1, ast::ptr<ast::Type> & type2, ast::TypeEnvironment & env,
1187 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1188 WidenMode widen, const ast::SymbolTable & symtab, ast::ptr<ast::Type> & common
1189 ) {
1190 ast::CV::Qualifiers q1 = type1->qualifiers, q2 = type2->qualifiers;
1191
1192 // force t1 and t2 to be cloned if their qualifiers must be stripped, so that type1 and
1193 // type2 are left unchanged; calling convention forces type{1,2}->strong_ref >= 1
1194 ast::ptr<ast::Type> t1{ type1 }, t2{ type2 };
1195 clear_qualifiers( t1 );
1196 clear_qualifiers( t2 );
1197
1198 if ( unifyExact( t1, t2, env, need, have, open, widen, symtab ) ) {
1199 t1 = nullptr; t2 = nullptr; // release t1, t2 to avoid spurious clones
1200
1201 // if exact unification on unqualified types, try to merge qualifiers
1202 if ( q1 == q2 || ( ( q1 > q2 || widen.first ) && ( q2 > q1 || widen.second ) ) ) {
1203 common.set_and_mutate( type1 )->qualifiers = q1 | q2;
1204 return true;
1205 } else {
1206 return false;
1207 }
1208
1209 } else if (( common = commonType( t1, t2, widen, symtab, env, open ) )) {
1210 t1 = nullptr; t2 = nullptr; // release t1, t2 to avoid spurious clones
1211
1212 // no exact unification, but common type
1213 common.get_and_mutate()->qualifiers = q1 | q2;
1214 return true;
1215 } else {
1216 return false;
1217 }
1218 }
1219
1220 ast::ptr<ast::Type> extractResultType( const ast::FunctionType * func ) {
1221 if ( func->returns.empty() ) return new ast::VoidType{};
1222 if ( func->returns.size() == 1 ) return func->returns[0]->get_type();
1223
1224 std::vector<ast::ptr<ast::Type>> tys;
1225 for ( const ast::DeclWithType * decl : func->returns ) {
1226 tys.emplace_back( decl->get_type() );
1227 }
1228 return new ast::TupleType{ std::move(tys) };
1229 }
1230} // namespace ResolvExpr
1231
1232// Local Variables: //
1233// tab-width: 4 //
1234// mode: c++ //
1235// compile-command: "make install" //
1236// End: //
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