source: src/ResolvExpr/Unify.cc@ 1b0184b

Last change on this file since 1b0184b was 8f31be6, checked in by Andrew Beach <ajbeach@…>, 2 years ago

Fixed some warnings, deleted some commented out code.
  • Property mode set to 100644
File size: 51.7 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// Unify.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sun May 17 12:27:10 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Fri Dec 13 23:43:05 2019
13// Update Count : 46
14//
15
16#include "Unify.h"
17
18#include <cassert> // for assertf, assert
19#include <iterator> // for back_insert_iterator, back_inserter
20#include <map> // for _Rb_tree_const_iterator, _Rb_tree_i...
21#include <memory> // for unique_ptr
22#include <set> // for set
23#include <string> // for string, operator==, operator!=, bas...
24#include <utility> // for pair, move
25#include <vector>
26
27#include "AST/Copy.hpp"
28#include "AST/Decl.hpp"
29#include "AST/Node.hpp"
30#include "AST/Pass.hpp"
31#include "AST/Print.hpp"
32#include "AST/Type.hpp"
33#include "AST/TypeEnvironment.hpp"
34#include "Common/Eval.h" // for eval
35#include "Common/PassVisitor.h" // for PassVisitor
36#include "CommonType.hpp" // for commonType
37#include "FindOpenVars.h" // for findOpenVars
38#include "SpecCost.hpp" // for SpecCost
39#include "SynTree/LinkageSpec.h" // for C
40#include "SynTree/Constant.h" // for Constant
41#include "SynTree/Declaration.h" // for TypeDecl, TypeDecl::Data, Declarati...
42#include "SynTree/Expression.h" // for TypeExpr, Expression, ConstantExpr
43#include "SynTree/Mutator.h" // for Mutator
44#include "SynTree/Type.h" // for Type, TypeInstType, FunctionType
45#include "SynTree/Visitor.h" // for Visitor
46#include "Tuples/Tuples.h" // for isTtype
47#include "TypeEnvironment.h" // for EqvClass, AssertionSet, OpenVarSet
48#include "typeops.h" // for flatten, occurs
49
50namespace ast {
51 class SymbolTable;
52}
53
54namespace SymTab {
55 class Indexer;
56} // namespace SymTab
57
58// #define DEBUG
59
60namespace ResolvExpr {
61
62// Template Helpers:
63template< typename Iterator1, typename Iterator2 >
64bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, std::list< Type* > &commonTypes ) {
65 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
66 Type *commonType = 0;
67 if ( ! unify( *list1Begin, *list2Begin, env, needAssertions, haveAssertions, openVars, indexer, commonType ) ) {
68 return false;
69 } // if
70 commonTypes.push_back( commonType );
71 } // for
72 return ( list1Begin == list1End && list2Begin == list2End );
73}
74
75template< typename Iterator1, typename Iterator2 >
76bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
77 std::list< Type* > commonTypes;
78 if ( unifyList( list1Begin, list1End, list2Begin, list2End, env, needAssertions, haveAssertions, openVars, indexer, commonTypes ) ) {
79 deleteAll( commonTypes );
80 return true;
81 } else {
82 return false;
83 } // if
84}
85
86 struct Unify_old : public WithShortCircuiting {
87 Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
88
89 bool get_result() const { return result; }
90
91 void previsit( BaseSyntaxNode * ) { visit_children = false; }
92
93 void postvisit( VoidType * voidType );
94 void postvisit( BasicType * basicType );
95 void postvisit( PointerType * pointerType );
96 void postvisit( ArrayType * arrayType );
97 void postvisit( ReferenceType * refType );
98 void postvisit( FunctionType * functionType );
99 void postvisit( StructInstType * aggregateUseType );
100 void postvisit( UnionInstType * aggregateUseType );
101 void postvisit( EnumInstType * aggregateUseType );
102 void postvisit( TraitInstType * aggregateUseType );
103 void postvisit( TypeInstType * aggregateUseType );
104 void postvisit( TupleType * tupleType );
105 void postvisit( VarArgsType * varArgsType );
106 void postvisit( ZeroType * zeroType );
107 void postvisit( OneType * oneType );
108
109 private:
110 template< typename RefType > void handleRefType( RefType *inst, Type *other );
111 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
112
113 bool result;
114 Type *type2; // inherited
115 TypeEnvironment &env;
116 AssertionSet &needAssertions;
117 AssertionSet &haveAssertions;
118 const OpenVarSet &openVars;
119 WidenMode widen;
120 const SymTab::Indexer &indexer;
121 };
122
123 /// Attempts an inexact unification of type1 and type2.
124 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
125 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common );
126 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
127
128 bool unifyExact(
129 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
130 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
131 WidenMode widen );
132
133 bool typesCompatible( const Type * first, const Type * second, const SymTab::Indexer & indexer, const TypeEnvironment & env ) {
134 TypeEnvironment newEnv;
135 OpenVarSet openVars, closedVars; // added closedVars
136 AssertionSet needAssertions, haveAssertions;
137 Type * newFirst = first->clone(), * newSecond = second->clone();
138 env.apply( newFirst );
139 env.apply( newSecond );
140
141 // do we need to do this? Seems like we do, types should be able to be compatible if they
142 // have free variables that can unify
143 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
144 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
145
146 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
147 delete newFirst;
148 delete newSecond;
149 return result;
150 }
151
152 bool typesCompatible(
153 const ast::Type * first, const ast::Type * second,
154 const ast::TypeEnvironment & env ) {
155 ast::TypeEnvironment newEnv;
156 ast::OpenVarSet open, closed;
157 ast::AssertionSet need, have;
158
159 ast::ptr<ast::Type> newFirst{ first }, newSecond{ second };
160 env.apply( newFirst );
161 env.apply( newSecond );
162
163 // findOpenVars( newFirst, open, closed, need, have, FirstClosed );
164 findOpenVars( newSecond, open, closed, need, have, newEnv, FirstOpen );
165
166 return unifyExact(newFirst, newSecond, newEnv, need, have, open, noWiden() );
167 }
168
169 bool typesCompatibleIgnoreQualifiers( const Type * first, const Type * second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
170 TypeEnvironment newEnv;
171 OpenVarSet openVars;
172 AssertionSet needAssertions, haveAssertions;
173 Type *newFirst = first->clone(), *newSecond = second->clone();
174 env.apply( newFirst );
175 env.apply( newSecond );
176 newFirst->get_qualifiers() = Type::Qualifiers();
177 newSecond->get_qualifiers() = Type::Qualifiers();
178
179 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
180 delete newFirst;
181 delete newSecond;
182 return result;
183 }
184
185 bool typesCompatibleIgnoreQualifiers(
186 const ast::Type * first, const ast::Type * second,
187 const ast::TypeEnvironment & env ) {
188 ast::TypeEnvironment newEnv;
189 ast::OpenVarSet open;
190 ast::AssertionSet need, have;
191
192 ast::Type * newFirst = shallowCopy( first );
193 ast::Type * newSecond = shallowCopy( second );
194 if ( auto temp = dynamic_cast<const ast::EnumInstType *>(first) ) {
195 if ( !dynamic_cast< const ast::EnumInstType * >( second ) ) {
196 const ast::EnumDecl * baseEnum = dynamic_cast<const ast::EnumDecl *>(temp->base.get());
197 if ( auto t = baseEnum->base.get() ) {
198 newFirst = ast::shallowCopy( t );
199 }
200 }
201 } else if ( auto temp = dynamic_cast<const ast::EnumInstType *>(second) ) {
202 const ast::EnumDecl * baseEnum = dynamic_cast<const ast::EnumDecl *>(temp->base.get());
203 if ( auto t = baseEnum->base.get() ) {
204 newSecond = ast::shallowCopy( t );
205 }
206 }
207
208 newFirst ->qualifiers = {};
209 newSecond->qualifiers = {};
210 ast::ptr< ast::Type > t1_(newFirst );
211 ast::ptr< ast::Type > t2_(newSecond);
212
213 ast::ptr< ast::Type > subFirst = env.apply(newFirst).node;
214 ast::ptr< ast::Type > subSecond = env.apply(newSecond).node;
215
216 return unifyExact(
217 subFirst,
218 subSecond,
219 newEnv, need, have, open, noWiden() );
220 }
221
222 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
223 OpenVarSet closedVars;
224 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
225 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
226 Type *commonType = 0;
227 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
228 if ( commonType ) {
229 delete commonType;
230 } // if
231 return true;
232 } else {
233 return false;
234 } // if
235 }
236
237 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
238 OpenVarSet closedVars;
239 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
240 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
241 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
242 }
243
244 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
245#ifdef DEBUG
246 TypeEnvironment debugEnv( env );
247#endif
248 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
249 return false;
250 }
251
252 bool result;
253 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
254 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
255 OpenVarSet::const_iterator entry1, entry2;
256 if ( var1 ) {
257 entry1 = openVars.find( var1->get_name() );
258 } // if
259 if ( var2 ) {
260 entry2 = openVars.find( var2->get_name() );
261 } // if
262 bool isopen1 = var1 && ( entry1 != openVars.end() );
263 bool isopen2 = var2 && ( entry2 != openVars.end() );
264
265 if ( isopen1 && isopen2 ) {
266 if ( entry1->second.kind != entry2->second.kind ) {
267 result = false;
268 } else {
269 result = env.bindVarToVar(
270 var1, var2, TypeDecl::Data{ entry1->second, entry2->second }, needAssertions,
271 haveAssertions, openVars, widen, indexer );
272 }
273 } else if ( isopen1 ) {
274 result = env.bindVar( var1, type2, entry1->second, needAssertions, haveAssertions, openVars, widen, indexer );
275 } else if ( isopen2 ) { // TODO: swap widen values in call, since type positions are flipped?
276 result = env.bindVar( var2, type1, entry2->second, needAssertions, haveAssertions, openVars, widen, indexer );
277 } else {
278 PassVisitor<Unify_old> comparator( type2, env, needAssertions, haveAssertions, openVars, widen, indexer );
279 type1->accept( comparator );
280 result = comparator.pass.get_result();
281 } // if
282#ifdef DEBUG
283 std::cerr << "============ unifyExact" << std::endl;
284 std::cerr << "type1 is ";
285 type1->print( std::cerr );
286 std::cerr << std::endl << "type2 is ";
287 type2->print( std::cerr );
288 std::cerr << std::endl << "openVars are ";
289 printOpenVarSet( openVars, std::cerr, 8 );
290 std::cerr << std::endl << "input env is " << std::endl;
291 debugEnv.print( std::cerr, 8 );
292 std::cerr << std::endl << "result env is " << std::endl;
293 env.print( std::cerr, 8 );
294 std::cerr << "result is " << result << std::endl;
295#endif
296 return result;
297 }
298
299 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
300 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
301 }
302
303 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common ) {
304 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
305 type1->get_qualifiers() = Type::Qualifiers();
306 type2->get_qualifiers() = Type::Qualifiers();
307 bool result;
308#ifdef DEBUG
309 std::cerr << "unifyInexact type 1 is ";
310 type1->print( std::cerr );
311 std::cerr << " type 2 is ";
312 type2->print( std::cerr );
313 std::cerr << std::endl;
314#endif
315 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widen, indexer ) ) {
316#ifdef DEBUG
317 std::cerr << "unifyInexact: no exact unification found" << std::endl;
318#endif
319 if ( ( common = commonType( type1, type2, widen.first, widen.second, indexer, env, openVars ) ) ) {
320 common->tq = tq1.unify( tq2 );
321#ifdef DEBUG
322 std::cerr << "unifyInexact: common type is ";
323 common->print( std::cerr );
324 std::cerr << std::endl;
325#endif
326 result = true;
327 } else {
328#ifdef DEBUG
329 std::cerr << "unifyInexact: no common type found" << std::endl;
330#endif
331 result = false;
332 } // if
333 } else {
334 if ( tq1 != tq2 ) {
335 if ( ( tq1 > tq2 || widen.first ) && ( tq2 > tq1 || widen.second ) ) {
336 common = type1->clone();
337 common->tq = tq1.unify( tq2 );
338 result = true;
339 } else {
340 result = false;
341 } // if
342 } else {
343 common = type1->clone();
344 common->tq = tq1.unify( tq2 );
345 result = true;
346 } // if
347 } // if
348 type1->get_qualifiers() = tq1;
349 type2->get_qualifiers() = tq2;
350 return result;
351 }
352
353 Unify_old::Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer )
354 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widen( widen ), indexer( indexer ) {
355 }
356
357 void Unify_old::postvisit( __attribute__((unused)) VoidType *voidType) {
358 result = dynamic_cast< VoidType* >( type2 );
359 }
360
361 void Unify_old::postvisit(BasicType *basicType) {
362 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
363 result = basicType->get_kind() == otherBasic->get_kind();
364 } // if
365 }
366
367 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
368 AssertionSet::iterator i = assertions.find( assert );
369 if ( i != assertions.end() ) {
370 i->second.isUsed = true;
371 } // if
372 }
373
374 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
375 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
376 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
377 markAssertionSet( assertion1, *assert );
378 markAssertionSet( assertion2, *assert );
379 } // for
380 } // for
381 }
382
383 void Unify_old::postvisit(PointerType *pointerType) {
384 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
385 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
386 markAssertions( haveAssertions, needAssertions, pointerType );
387 markAssertions( haveAssertions, needAssertions, otherPointer );
388 } // if
389 }
390
391 void Unify_old::postvisit(ReferenceType *refType) {
392 if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) {
393 result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
394 markAssertions( haveAssertions, needAssertions, refType );
395 markAssertions( haveAssertions, needAssertions, otherRef );
396 } // if
397 }
398
399 void Unify_old::postvisit(ArrayType *arrayType) {
400 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
401 // to unify, array types must both be VLA or both not VLA
402 // and must both have a dimension expression or not have a dimension
403 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
404
405 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
406 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
407 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
408 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
409 // see C11 Reference Manual 6.7.6.2.6
410 // two array types with size specifiers that are integer constant expressions are
411 // compatible if both size specifiers have the same constant value
412 if ( ce1 && ce2 ) {
413 Constant * c1 = ce1->get_constant();
414 Constant * c2 = ce2->get_constant();
415
416 if ( c1->get_value() != c2->get_value() ) {
417 // does not unify if the dimension is different
418 return;
419 }
420 }
421 }
422
423 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
424 } // if
425 }
426
427 template< typename Iterator, typename Func >
428 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
429 std::list< Type * > types;
430 for ( ; begin != end; ++begin ) {
431 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
432 flatten( toType( *begin ), back_inserter( types ) );
433 }
434 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
435 }
436
437 template< typename Iterator1, typename Iterator2 >
438 bool unifyTypeList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
439 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
440 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
441 Type * t1 = (*list1Begin)->get_type();
442 Type * t2 = (*list2Begin)->get_type();
443 bool isTtype1 = Tuples::isTtype( t1 );
444 bool isTtype2 = Tuples::isTtype( t2 );
445 // xxx - assumes ttype must be last parameter
446 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
447 if ( isTtype1 && ! isTtype2 ) {
448 // combine all of the things in list2, then unify
449 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
450 } else if ( isTtype2 && ! isTtype1 ) {
451 // combine all of the things in list1, then unify
452 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
453 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
454 return false;
455 } // if
456 } // for
457 // 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
458 if ( list1Begin != list1End ) {
459 // try unifying empty tuple type with ttype
460 Type * t1 = (*list1Begin)->get_type();
461 if ( Tuples::isTtype( t1 ) ) {
462 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
463 } else return false;
464 } else if ( list2Begin != list2End ) {
465 // try unifying empty tuple type with ttype
466 Type * t2 = (*list2Begin)->get_type();
467 if ( Tuples::isTtype( t2 ) ) {
468 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
469 } else return false;
470 } else {
471 return true;
472 } // if
473 }
474
475 /// Finds ttypes and replaces them with their expansion, if known.
476 /// This needs to be done so that satisfying ttype assertions is easier.
477 /// If this isn't done then argument lists can have wildly different
478 /// size and structure, when they should be compatible.
479 struct TtypeExpander_old : public WithShortCircuiting {
480 TypeEnvironment & tenv;
481 TtypeExpander_old( TypeEnvironment & tenv ) : tenv( tenv ) {}
482 void premutate( TypeInstType * ) { visit_children = false; }
483 Type * postmutate( TypeInstType * typeInst ) {
484 if ( const EqvClass *eqvClass = tenv.lookup( typeInst->get_name() ) ) {
485 // expand ttype parameter into its actual type
486 if ( eqvClass->data.kind == TypeDecl::Ttype && eqvClass->type ) {
487 delete typeInst;
488 return eqvClass->type->clone();
489 }
490 }
491 return typeInst;
492 }
493 };
494
495 /// flattens a list of declarations, so that each tuple type has a single declaration.
496 /// makes use of TtypeExpander to ensure ttypes are flat as well.
497 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
498 dst.clear();
499 for ( DeclarationWithType * dcl : src ) {
500 PassVisitor<TtypeExpander_old> expander( env );
501 dcl->acceptMutator( expander );
502 std::list< Type * > types;
503 flatten( dcl->get_type(), back_inserter( types ) );
504 for ( Type * t : types ) {
505 // 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.
506 // 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.
507 t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic);
508
509 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
510 }
511 delete dcl;
512 }
513 }
514
515 void Unify_old::postvisit(FunctionType *functionType) {
516 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
517 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
518 // flatten the parameter lists for both functions so that tuple structure
519 // doesn't affect unification. Must be a clone so that the types don't change.
520 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
521 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
522 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
523 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
524
525 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
526 if (
527 (flatFunc->parameters.size() == flatOther->parameters.size() &&
528 flatFunc->returnVals.size() == flatOther->returnVals.size())
529 || flatFunc->isTtype()
530 || flatOther->isTtype()
531 ) {
532 if ( unifyTypeList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
533 if ( unifyTypeList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->returnVals.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
534
535 // the original types must be used in mark assertions, since pointer comparisons are used
536 markAssertions( haveAssertions, needAssertions, functionType );
537 markAssertions( haveAssertions, needAssertions, otherFunction );
538
539 result = true;
540 } // if
541 } // if
542 } // if
543 } // if
544 }
545
546 template< typename RefType >
547 void Unify_old::handleRefType( RefType *inst, Type *other ) {
548 // check that other type is compatible and named the same
549 RefType *otherStruct = dynamic_cast< RefType* >( other );
550 result = otherStruct && inst->name == otherStruct->name;
551 }
552
553 template< typename RefType >
554 void Unify_old::handleGenericRefType( RefType *inst, Type *other ) {
555 // Check that other type is compatible and named the same
556 handleRefType( inst, other );
557 if ( ! result ) return;
558 // Check that parameters of types unify, if any
559 std::list< Expression* > params = inst->parameters;
560 std::list< Expression* > otherParams = ((RefType*)other)->parameters;
561
562 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
563 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
564 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
565 assertf(param, "Aggregate parameters should be type expressions");
566 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
567 assertf(otherParam, "Aggregate parameters should be type expressions");
568
569 Type* paramTy = param->get_type();
570 Type* otherParamTy = otherParam->get_type();
571
572 bool tupleParam = Tuples::isTtype( paramTy );
573 bool otherTupleParam = Tuples::isTtype( otherParamTy );
574
575 if ( tupleParam && otherTupleParam ) {
576 ++it; ++jt; // skip ttype parameters for break
577 } else if ( tupleParam ) {
578 // bundle other parameters into tuple to match
579 std::list< Type * > binderTypes;
580
581 do {
582 binderTypes.push_back( otherParam->get_type()->clone() );
583 ++jt;
584
585 if ( jt == otherParams.end() ) break;
586
587 otherParam = dynamic_cast< TypeExpr* >(*jt);
588 assertf(otherParam, "Aggregate parameters should be type expressions");
589 } while (true);
590
591 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
592 ++it; // skip ttype parameter for break
593 } else if ( otherTupleParam ) {
594 // bundle parameters into tuple to match other
595 std::list< Type * > binderTypes;
596
597 do {
598 binderTypes.push_back( param->get_type()->clone() );
599 ++it;
600
601 if ( it == params.end() ) break;
602
603 param = dynamic_cast< TypeExpr* >(*it);
604 assertf(param, "Aggregate parameters should be type expressions");
605 } while (true);
606
607 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
608 ++jt; // skip ttype parameter for break
609 }
610
611 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
612 result = false;
613 return;
614 }
615
616 // ttype parameter should be last
617 if ( tupleParam || otherTupleParam ) break;
618 }
619 result = ( it == params.end() && jt == otherParams.end() );
620 }
621
622 void Unify_old::postvisit(StructInstType *structInst) {
623 handleGenericRefType( structInst, type2 );
624 }
625
626 void Unify_old::postvisit(UnionInstType *unionInst) {
627 handleGenericRefType( unionInst, type2 );
628 }
629
630 void Unify_old::postvisit(EnumInstType *enumInst) {
631 handleRefType( enumInst, type2 );
632 }
633
634 void Unify_old::postvisit(TraitInstType *contextInst) {
635 handleRefType( contextInst, type2 );
636 }
637
638 void Unify_old::postvisit(TypeInstType *typeInst) {
639 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
640 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
641 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
642 result = true;
643/// } else {
644/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
645/// if ( nt ) {
646/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
647/// assert( type );
648/// if ( type->get_base() ) {
649/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
650/// }
651/// }
652 } // if
653 }
654
655 template< typename Iterator1, typename Iterator2 >
656 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
657 auto get_type = [](Type * t) { return t; };
658 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
659 Type * t1 = *list1Begin;
660 Type * t2 = *list2Begin;
661 bool isTtype1 = Tuples::isTtype( t1 );
662 bool isTtype2 = Tuples::isTtype( t2 );
663 // xxx - assumes ttype must be last parameter
664 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
665 if ( isTtype1 && ! isTtype2 ) {
666 // combine all of the things in list2, then unify
667 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
668 } else if ( isTtype2 && ! isTtype1 ) {
669 // combine all of the things in list1, then unify
670 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
671 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
672 return false;
673 } // if
674
675 } // for
676 if ( list1Begin != list1End ) {
677 // try unifying empty tuple type with ttype
678 Type * t1 = *list1Begin;
679 if ( Tuples::isTtype( t1 ) ) {
680 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
681 } else return false;
682 } else if ( list2Begin != list2End ) {
683 // try unifying empty tuple type with ttype
684 Type * t2 = *list2Begin;
685 if ( Tuples::isTtype( t2 ) ) {
686 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
687 } else return false;
688 } else {
689 return true;
690 } // if
691 }
692
693 void Unify_old::postvisit(TupleType *tupleType) {
694 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
695 std::unique_ptr<TupleType> flat1( tupleType->clone() );
696 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
697 std::list<Type *> types1, types2;
698
699 PassVisitor<TtypeExpander_old> expander( env );
700 flat1->acceptMutator( expander );
701 flat2->acceptMutator( expander );
702
703 flatten( flat1.get(), back_inserter( types1 ) );
704 flatten( flat2.get(), back_inserter( types2 ) );
705
706 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
707 } // if
708 }
709
710 void Unify_old::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) {
711 result = dynamic_cast< VarArgsType* >( type2 );
712 }
713
714 void Unify_old::postvisit( __attribute__((unused)) ZeroType *zeroType ) {
715 result = dynamic_cast< ZeroType* >( type2 );
716 }
717
718 void Unify_old::postvisit( __attribute__((unused)) OneType *oneType ) {
719 result = dynamic_cast< OneType* >( type2 );
720 }
721
722 Type * extractResultType( FunctionType * function ) {
723 if ( function->get_returnVals().size() == 0 ) {
724 return new VoidType( Type::Qualifiers() );
725 } else if ( function->get_returnVals().size() == 1 ) {
726 return function->get_returnVals().front()->get_type()->clone();
727 } else {
728 std::list< Type * > types;
729 for ( DeclarationWithType * decl : function->get_returnVals() ) {
730 types.push_back( decl->get_type()->clone() );
731 } // for
732 return new TupleType( Type::Qualifiers(), types );
733 }
734 }
735
736 namespace {
737 /// Replaces ttype variables with their bound types.
738 /// If this isn't done when satifying ttype assertions, then argument lists can have
739 /// different size and structure when they should be compatible.
740 struct TtypeExpander_new : public ast::WithShortCircuiting, public ast::PureVisitor {
741 ast::TypeEnvironment & tenv;
742
743 TtypeExpander_new( ast::TypeEnvironment & env ) : tenv( env ) {}
744
745 const ast::Type * postvisit( const ast::TypeInstType * typeInst ) {
746 if ( const ast::EqvClass * clz = tenv.lookup( *typeInst ) ) {
747 // expand ttype parameter into its actual type
748 if ( clz->data.kind == ast::TypeDecl::Ttype && clz->bound ) {
749 return clz->bound;
750 }
751 }
752 return typeInst;
753 }
754 };
755 }
756
757 std::vector< ast::ptr< ast::Type > > flattenList(
758 const std::vector< ast::ptr< ast::Type > > & src, ast::TypeEnvironment & env
759 ) {
760 std::vector< ast::ptr< ast::Type > > dst;
761 dst.reserve( src.size() );
762 for ( const auto & d : src ) {
763 ast::Pass<TtypeExpander_new> expander{ env };
764 // TtypeExpander pass is impure (may mutate nodes in place)
765 // need to make nodes shared to prevent accidental mutation
766 ast::ptr<ast::Type> dc = d->accept(expander);
767 auto types = flatten( dc );
768 for ( ast::ptr< ast::Type > & t : types ) {
769 // outermost const, volatile, _Atomic qualifiers in parameters should not play
770 // a role in the unification of function types, since they do not determine
771 // whether a function is callable.
772 // NOTE: **must** consider at least mutex qualifier, since functions can be
773 // overloaded on outermost mutex and a mutex function has different
774 // requirements than a non-mutex function
775 remove_qualifiers( t, ast::CV::Const | ast::CV::Volatile | ast::CV::Atomic );
776 dst.emplace_back( t );
777 }
778 }
779 return dst;
780 }
781
782 // Unification of Expressions
783 //
784 // Boolean outcome (obvious): Are they basically spelled the same?
785 // Side effect of binding variables (subtle): if `sizeof(int)` ===_expr `sizeof(T)` then `int` ===_ty `T`
786 //
787 // Context: if `float[VAREXPR1]` ===_ty `float[VAREXPR2]` then `VAREXPR1` ===_expr `VAREXPR2`
788 // where the VAREXPR are meant as notational metavariables representing the fact that unification always
789 // sees distinct ast::VariableExpr objects at these positions
790
791 static bool unify( const ast::Expr * e1, const ast::Expr * e2, ast::TypeEnvironment & env,
792 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
793 WidenMode widen );
794
795 class UnifyExpr final : public ast::WithShortCircuiting {
796 const ast::Expr * e2;
797 ast::TypeEnvironment & tenv;
798 ast::AssertionSet & need;
799 ast::AssertionSet & have;
800 const ast::OpenVarSet & open;
801 WidenMode widen;
802 public:
803 bool result;
804
805 private:
806
807 void tryMatchOnStaticValue( const ast::Expr * e1 ) {
808 Evaluation r1 = eval(e1);
809 Evaluation r2 = eval(e2);
810
811 if ( ! r1.hasKnownValue ) return;
812 if ( ! r2.hasKnownValue ) return;
813
814 if (r1.knownValue != r2.knownValue) return;
815
816 visit_children = false;
817 result = true;
818 }
819
820 public:
821
822 void previsit( const ast::Node * ) { assert(false); }
823
824 void previsit( const ast::Expr * e1 ) {
825 tryMatchOnStaticValue( e1 );
826 visit_children = false;
827 }
828
829 void previsit( const ast::CastExpr * e1 ) {
830 tryMatchOnStaticValue( e1 );
831
832 if (result) {
833 assert (visit_children == false);
834 } else {
835 assert (visit_children == true);
836 visit_children = false;
837
838 auto e2c = dynamic_cast< const ast::CastExpr * >( e2 );
839 if ( ! e2c ) return;
840
841 // inspect casts' target types
842 if ( ! unifyExact(
843 e1->result, e2c->result, tenv, need, have, open, widen ) ) return;
844
845 // inspect casts' inner expressions
846 result = unify( e1->arg, e2c->arg, tenv, need, have, open, widen );
847 }
848 }
849
850 void previsit( const ast::VariableExpr * e1 ) {
851 tryMatchOnStaticValue( e1 );
852
853 if (result) {
854 assert (visit_children == false);
855 } else {
856 assert (visit_children == true);
857 visit_children = false;
858
859 auto e2v = dynamic_cast< const ast::VariableExpr * >( e2 );
860 if ( ! e2v ) return;
861
862 assert(e1->var);
863 assert(e2v->var);
864
865 // conservative: variable exprs match if their declarations are represented by the same C++ AST object
866 result = (e1->var == e2v->var);
867 }
868 }
869
870 void previsit( const ast::SizeofExpr * e1 ) {
871 tryMatchOnStaticValue( e1 );
872
873 if (result) {
874 assert (visit_children == false);
875 } else {
876 assert (visit_children == true);
877 visit_children = false;
878
879 auto e2so = dynamic_cast< const ast::SizeofExpr * >( e2 );
880 if ( ! e2so ) return;
881
882 assert((e1->type != nullptr) ^ (e1->expr != nullptr));
883 assert((e2so->type != nullptr) ^ (e2so->expr != nullptr));
884 if ( ! (e1->type && e2so->type) ) return;
885
886 // expression unification calls type unification (mutual recursion)
887 result = unifyExact( e1->type, e2so->type, tenv, need, have, open, widen );
888 }
889 }
890
891 UnifyExpr( const ast::Expr * e2, ast::TypeEnvironment & env, ast::AssertionSet & need,
892 ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen )
893 : e2( e2 ), tenv(env), need(need), have(have), open(open), widen(widen), result(false) {}
894 };
895
896 static bool unify( const ast::Expr * e1, const ast::Expr * e2, ast::TypeEnvironment & env,
897 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
898 WidenMode widen ) {
899 assert( e1 && e2 );
900 return ast::Pass<UnifyExpr>::read( e1, e2, env, need, have, open, widen );
901 }
902
903 class Unify_new final : public ast::WithShortCircuiting {
904 const ast::Type * type2;
905 ast::TypeEnvironment & tenv;
906 ast::AssertionSet & need;
907 ast::AssertionSet & have;
908 const ast::OpenVarSet & open;
909 WidenMode widen;
910 public:
911 static size_t traceId;
912 bool result;
913
914 Unify_new(
915 const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need,
916 ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen )
917 : type2(type2), tenv(env), need(need), have(have), open(open), widen(widen),
918 result(false) {}
919
920 void previsit( const ast::Node * ) { visit_children = false; }
921
922 void postvisit( const ast::VoidType * ) {
923 result = dynamic_cast< const ast::VoidType * >( type2 );
924 }
925
926 void postvisit( const ast::BasicType * basic ) {
927 if ( auto basic2 = dynamic_cast< const ast::BasicType * >( type2 ) ) {
928 result = basic->kind == basic2->kind;
929 }
930 }
931
932 void postvisit( const ast::PointerType * pointer ) {
933 if ( auto pointer2 = dynamic_cast< const ast::PointerType * >( type2 ) ) {
934 result = unifyExact(
935 pointer->base, pointer2->base, tenv, need, have, open,
936 noWiden());
937 }
938 }
939
940 void postvisit( const ast::ArrayType * array ) {
941 auto array2 = dynamic_cast< const ast::ArrayType * >( type2 );
942 if ( ! array2 ) return;
943
944 if ( array->isVarLen != array2->isVarLen ) return;
945 if ( (array->dimension != nullptr) != (array2->dimension != nullptr) ) return;
946
947 if ( array->dimension ) {
948 assert( array2->dimension );
949 // type unification calls expression unification (mutual recursion)
950 if ( ! unify(array->dimension, array2->dimension,
951 tenv, need, have, open, widen) ) return;
952 }
953
954 result = unifyExact(
955 array->base, array2->base, tenv, need, have, open, noWiden());
956 }
957
958 void postvisit( const ast::ReferenceType * ref ) {
959 if ( auto ref2 = dynamic_cast< const ast::ReferenceType * >( type2 ) ) {
960 result = unifyExact(
961 ref->base, ref2->base, tenv, need, have, open, noWiden());
962 }
963 }
964
965 private:
966
967 template< typename Iter >
968 static bool unifyTypeList(
969 Iter crnt1, Iter end1, Iter crnt2, Iter end2, ast::TypeEnvironment & env,
970 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open
971 ) {
972 while ( crnt1 != end1 && crnt2 != end2 ) {
973 const ast::Type * t1 = *crnt1;
974 const ast::Type * t2 = *crnt2;
975 bool isTuple1 = Tuples::isTtype( t1 );
976 bool isTuple2 = Tuples::isTtype( t2 );
977
978 // assumes here that ttype *must* be last parameter
979 if ( isTuple1 && ! isTuple2 ) {
980 // combine remainder of list2, then unify
981 return unifyExact(
982 t1, tupleFromTypes( crnt2, end2 ), env, need, have, open,
983 noWiden() );
984 } else if ( ! isTuple1 && isTuple2 ) {
985 // combine remainder of list1, then unify
986 return unifyExact(
987 tupleFromTypes( crnt1, end1 ), t2, env, need, have, open,
988 noWiden() );
989 }
990
991 if ( ! unifyExact(
992 t1, t2, env, need, have, open, noWiden() )
993 ) return false;
994
995 ++crnt1; ++crnt2;
996 }
997
998 // May get to the end of one argument list before the other. This is only okay if the
999 // other is a ttype
1000 if ( crnt1 != end1 ) {
1001 // try unifying empty tuple with ttype
1002 const ast::Type * t1 = *crnt1;
1003 if ( ! Tuples::isTtype( t1 ) ) return false;
1004 return unifyExact(
1005 t1, tupleFromTypes( crnt2, end2 ), env, need, have, open,
1006 noWiden() );
1007 } else if ( crnt2 != end2 ) {
1008 // try unifying empty tuple with ttype
1009 const ast::Type * t2 = *crnt2;
1010 if ( ! Tuples::isTtype( t2 ) ) return false;
1011 return unifyExact(
1012 tupleFromTypes( crnt1, end1 ), t2, env, need, have, open,
1013 noWiden() );
1014 }
1015
1016 return true;
1017 }
1018
1019 static bool unifyTypeList(
1020 const std::vector< ast::ptr< ast::Type > > & list1,
1021 const std::vector< ast::ptr< ast::Type > > & list2,
1022 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1023 const ast::OpenVarSet & open
1024 ) {
1025 return unifyTypeList(
1026 list1.begin(), list1.end(), list2.begin(), list2.end(), env, need, have, open);
1027 }
1028
1029 static void markAssertionSet( ast::AssertionSet & assns, const ast::VariableExpr * assn ) {
1030 auto i = assns.find( assn );
1031 if ( i != assns.end() ) {
1032 i->second.isUsed = true;
1033 }
1034 }
1035
1036 /// mark all assertions in `type` used in both `assn1` and `assn2`
1037 static void markAssertions(
1038 ast::AssertionSet & assn1, ast::AssertionSet & assn2,
1039 const ast::FunctionType * type
1040 ) {
1041 for ( auto & assert : type->assertions ) {
1042 markAssertionSet( assn1, assert );
1043 markAssertionSet( assn2, assert );
1044 }
1045 }
1046
1047 public:
1048 void postvisit( const ast::FunctionType * func ) {
1049 auto func2 = dynamic_cast< const ast::FunctionType * >( type2 );
1050 if ( ! func2 ) return;
1051
1052 if ( func->isVarArgs != func2->isVarArgs ) return;
1053
1054 // Flatten the parameter lists for both functions so that tuple structure does not
1055 // affect unification. Does not actually mutate function parameters.
1056 auto params = flattenList( func->params, tenv );
1057 auto params2 = flattenList( func2->params, tenv );
1058
1059 // sizes don't have to match if ttypes are involved; need to be more precise w.r.t.
1060 // where the ttype is to prevent errors
1061 if (
1062 ( params.size() != params2.size() || func->returns.size() != func2->returns.size() )
1063 && ! func->isTtype()
1064 && ! func2->isTtype()
1065 ) return;
1066
1067 if ( ! unifyTypeList( params, params2, tenv, need, have, open ) ) return;
1068 if ( ! unifyTypeList(
1069 func->returns, func2->returns, tenv, need, have, open ) ) return;
1070
1071 markAssertions( have, need, func );
1072 markAssertions( have, need, func2 );
1073
1074 result = true;
1075 }
1076
1077 private:
1078 // Returns: other, cast as XInstType
1079 // Assigns this->result: whether types are compatible (up to generic parameters)
1080 template< typename XInstType >
1081 const XInstType * handleRefType( const XInstType * inst, const ast::Type * other ) {
1082 // check that the other type is compatible and named the same
1083 auto otherInst = dynamic_cast< const XInstType * >( other );
1084 if (otherInst && inst->name == otherInst->name)
1085 this->result = otherInst;
1086 return otherInst;
1087 }
1088
1089 /// Creates a tuple type based on a list of TypeExpr
1090 template< typename Iter >
1091 static const ast::Type * tupleFromExprs(
1092 const ast::TypeExpr * param, Iter & crnt, Iter end, ast::CV::Qualifiers qs
1093 ) {
1094 std::vector< ast::ptr< ast::Type > > types;
1095 do {
1096 types.emplace_back( param->type );
1097
1098 ++crnt;
1099 if ( crnt == end ) break;
1100 param = strict_dynamic_cast< const ast::TypeExpr * >( crnt->get() );
1101 } while(true);
1102
1103 return new ast::TupleType{ std::move(types), qs };
1104 }
1105
1106 template< typename XInstType >
1107 void handleGenericRefType( const XInstType * inst, const ast::Type * other ) {
1108 // check that other type is compatible and named the same
1109 const XInstType * otherInst = handleRefType( inst, other );
1110 if ( ! this->result ) return;
1111
1112 // check that parameters of types unify, if any
1113 const std::vector< ast::ptr< ast::Expr > > & params = inst->params;
1114 const std::vector< ast::ptr< ast::Expr > > & params2 = otherInst->params;
1115
1116 auto it = params.begin();
1117 auto jt = params2.begin();
1118 for ( ; it != params.end() && jt != params2.end(); ++it, ++jt ) {
1119 auto param = strict_dynamic_cast< const ast::TypeExpr * >( it->get() );
1120 auto param2 = strict_dynamic_cast< const ast::TypeExpr * >( jt->get() );
1121
1122 ast::ptr< ast::Type > pty = param->type;
1123 ast::ptr< ast::Type > pty2 = param2->type;
1124
1125 bool isTuple = Tuples::isTtype( pty );
1126 bool isTuple2 = Tuples::isTtype( pty2 );
1127
1128 if ( isTuple && isTuple2 ) {
1129 ++it; ++jt; // skip ttype parameters before break
1130 } else if ( isTuple ) {
1131 // bundle remaining params into tuple
1132 pty2 = tupleFromExprs( param2, jt, params2.end(), pty->qualifiers );
1133 ++it; // skip ttype parameter for break
1134 } else if ( isTuple2 ) {
1135 // bundle remaining params into tuple
1136 pty = tupleFromExprs( param, it, params.end(), pty2->qualifiers );
1137 ++jt; // skip ttype parameter for break
1138 }
1139
1140 if ( ! unifyExact(
1141 pty, pty2, tenv, need, have, open, noWiden() ) ) {
1142 result = false;
1143 return;
1144 }
1145
1146 // ttype parameter should be last
1147 if ( isTuple || isTuple2 ) break;
1148 }
1149 result = it == params.end() && jt == params2.end();
1150 }
1151
1152 public:
1153 void postvisit( const ast::StructInstType * aggrType ) {
1154 handleGenericRefType( aggrType, type2 );
1155 }
1156
1157 void postvisit( const ast::UnionInstType * aggrType ) {
1158 handleGenericRefType( aggrType, type2 );
1159 }
1160
1161 void postvisit( const ast::EnumInstType * aggrType ) {
1162 handleRefType( aggrType, type2 );
1163 }
1164
1165 void postvisit( const ast::TraitInstType * aggrType ) {
1166 handleRefType( aggrType, type2 );
1167 }
1168
1169 void postvisit( const ast::TypeInstType * typeInst ) {
1170 // assert( open.find( *typeInst ) == open.end() );
1171 auto otherInst = dynamic_cast< const ast::TypeInstType * >( type2 );
1172 if (otherInst && typeInst->name == otherInst->name)
1173 this->result = otherInst;
1174 // return otherInst;
1175 }
1176
1177 private:
1178 /// Creates a tuple type based on a list of Type
1179
1180 static bool unifyList(
1181 const std::vector< ast::ptr< ast::Type > > & list1,
1182 const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env,
1183 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open
1184 ) {
1185 auto crnt1 = list1.begin();
1186 auto crnt2 = list2.begin();
1187 while ( crnt1 != list1.end() && crnt2 != list2.end() ) {
1188 const ast::Type * t1 = *crnt1;
1189 const ast::Type * t2 = *crnt2;
1190 bool isTuple1 = Tuples::isTtype( t1 );
1191 bool isTuple2 = Tuples::isTtype( t2 );
1192
1193 // assumes ttype must be last parameter
1194 if ( isTuple1 && ! isTuple2 ) {
1195 // combine entirety of list2, then unify
1196 return unifyExact(
1197 t1, tupleFromTypes( list2 ), env, need, have, open,
1198 noWiden() );
1199 } else if ( ! isTuple1 && isTuple2 ) {
1200 // combine entirety of list1, then unify
1201 return unifyExact(
1202 tupleFromTypes( list1 ), t2, env, need, have, open,
1203 noWiden() );
1204 }
1205
1206 if ( ! unifyExact(
1207 t1, t2, env, need, have, open, noWiden() )
1208 ) return false;
1209
1210 ++crnt1; ++crnt2;
1211 }
1212
1213 if ( crnt1 != list1.end() ) {
1214 // try unifying empty tuple type with ttype
1215 const ast::Type * t1 = *crnt1;
1216 if ( ! Tuples::isTtype( t1 ) ) return false;
1217 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1218 // from Rob's code
1219 return unifyExact(
1220 t1, tupleFromTypes( list2 ), env, need, have, open,
1221 noWiden() );
1222 } else if ( crnt2 != list2.end() ) {
1223 // try unifying empty tuple with ttype
1224 const ast::Type * t2 = *crnt2;
1225 if ( ! Tuples::isTtype( t2 ) ) return false;
1226 // xxx - this doesn't generate an empty tuple, contrary to comment; both ported
1227 // from Rob's code
1228 return unifyExact(
1229 tupleFromTypes( list1 ), t2, env, need, have, open,
1230 noWiden() );
1231 }
1232
1233 return true;
1234 }
1235
1236 public:
1237 void postvisit( const ast::TupleType * tuple ) {
1238 auto tuple2 = dynamic_cast< const ast::TupleType * >( type2 );
1239 if ( ! tuple2 ) return;
1240
1241 ast::Pass<TtypeExpander_new> expander{ tenv };
1242
1243 const ast::Type * flat = tuple->accept( expander );
1244 const ast::Type * flat2 = tuple2->accept( expander );
1245
1246 auto types = flatten( flat );
1247 auto types2 = flatten( flat2 );
1248
1249 result = unifyList( types, types2, tenv, need, have, open );
1250 }
1251
1252 void postvisit( const ast::VarArgsType * ) {
1253 result = dynamic_cast< const ast::VarArgsType * >( type2 );
1254 }
1255
1256 void postvisit( const ast::ZeroType * ) {
1257 result = dynamic_cast< const ast::ZeroType * >( type2 );
1258 }
1259
1260 void postvisit( const ast::OneType * ) {
1261 result = dynamic_cast< const ast::OneType * >( type2 );
1262 }
1263
1264 private:
1265 template< typename RefType > void handleRefType( RefType *inst, Type *other );
1266 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
1267 };
1268
1269 // size_t Unify_new::traceId = Stats::Heap::new_stacktrace_id("Unify_new");
1270 bool unify(
1271 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1272 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1273 ast::OpenVarSet & open
1274 ) {
1275 ast::ptr<ast::Type> common;
1276 return unify( type1, type2, env, need, have, open, common );
1277 }
1278
1279 bool unify(
1280 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1281 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1282 ast::OpenVarSet & open, ast::ptr<ast::Type> & common
1283 ) {
1284 ast::OpenVarSet closed;
1285 // findOpenVars( type1, open, closed, need, have, FirstClosed );
1286 findOpenVars( type2, open, closed, need, have, env, FirstOpen );
1287 return unifyInexact(
1288 type1, type2, env, need, have, open, WidenMode{ true, true }, common );
1289 }
1290
1291 bool unifyExact(
1292 const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env,
1293 ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open,
1294 WidenMode widen
1295 ) {
1296 if ( type1->qualifiers != type2->qualifiers ) return false;
1297
1298 auto var1 = dynamic_cast< const ast::TypeInstType * >( type1 );
1299 auto var2 = dynamic_cast< const ast::TypeInstType * >( type2 );
1300 bool isopen1 = var1 && env.lookup(*var1);
1301 bool isopen2 = var2 && env.lookup(*var2);
1302
1303 if ( isopen1 && isopen2 ) {
1304 if ( var1->base->kind != var2->base->kind ) return false;
1305 return env.bindVarToVar(
1306 var1, var2, ast::TypeData{ var1->base->kind, var1->base->sized||var2->base->sized }, need, have,
1307 open, widen );
1308 } else if ( isopen1 ) {
1309 return env.bindVar( var1, type2, ast::TypeData{var1->base}, need, have, open, widen );
1310 } else if ( isopen2 ) {
1311 return env.bindVar( var2, type1, ast::TypeData{var2->base}, need, have, open, widen );
1312 } else {
1313 return ast::Pass<Unify_new>::read(
1314 type1, type2, env, need, have, open, widen );
1315 }
1316 }
1317
1318 bool unifyInexact(
1319 const ast::ptr<ast::Type> & type1, const ast::ptr<ast::Type> & type2,
1320 ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have,
1321 const ast::OpenVarSet & open, WidenMode widen,
1322 ast::ptr<ast::Type> & common
1323 ) {
1324 ast::CV::Qualifiers q1 = type1->qualifiers, q2 = type2->qualifiers;
1325
1326 // force t1 and t2 to be cloned if their qualifiers must be stripped, so that type1 and
1327 // type2 are left unchanged; calling convention forces type{1,2}->strong_ref >= 1
1328 ast::Type * t1 = shallowCopy(type1.get());
1329 ast::Type * t2 = shallowCopy(type2.get());
1330 t1->qualifiers = {};
1331 t2->qualifiers = {};
1332 ast::ptr< ast::Type > t1_(t1);
1333 ast::ptr< ast::Type > t2_(t2);
1334
1335 if ( unifyExact( t1, t2, env, need, have, open, widen ) ) {
1336 // if exact unification on unqualified types, try to merge qualifiers
1337 if ( q1 == q2 || ( ( q1 > q2 || widen.first ) && ( q2 > q1 || widen.second ) ) ) {
1338 t1->qualifiers = q1 | q2;
1339 common = t1;
1340 return true;
1341 } else {
1342 return false;
1343 }
1344
1345 } else if (( common = commonType( t1, t2, env, need, have, open, widen ))) {
1346 // no exact unification, but common type
1347 auto c = shallowCopy(common.get());
1348 c->qualifiers = q1 | q2;
1349 common = c;
1350 return true;
1351 } else {
1352 return false;
1353 }
1354 }
1355
1356 ast::ptr<ast::Type> extractResultType( const ast::FunctionType * func ) {
1357 if ( func->returns.empty() ) return new ast::VoidType{};
1358 if ( func->returns.size() == 1 ) return func->returns[0];
1359
1360 std::vector<ast::ptr<ast::Type>> tys;
1361 for ( const auto & decl : func->returns ) {
1362 tys.emplace_back( decl );
1363 }
1364 return new ast::TupleType{ std::move(tys) };
1365 }
1366} // namespace ResolvExpr
1367
1368// Local Variables: //
1369// tab-width: 4 //
1370// mode: c++ //
1371// compile-command: "make install" //
1372// End: //
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