source: src/ResolvExpr/Unify.cc@ 3eab0ef6

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors deferred_resn demangler enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr new-env no_list persistent-indexer pthread-emulation qualifiedEnum resolv-new with_gc
Last change on this file since 3eab0ef6 was ea6332d, checked in by Thierry Delisle <tdelisle@…>, 8 years ago

Big header cleaning pass - commit 3
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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 : Thu Mar 16 16:22:54 2017
13// Update Count : 42
14//
15
16#include <cassert> // for assertf, assert
17#include <iterator> // for back_insert_iterator, back_inserter
18#include <map> // for _Rb_tree_const_iterator, _Rb_tree_i...
19#include <memory> // for unique_ptr, auto_ptr
20#include <set> // for set
21#include <string> // for string, operator==, operator!=, bas...
22#include <utility> // for pair
23
24#include "FindOpenVars.h" // for findOpenVars
25#include "Parser/LinkageSpec.h" // for C
26#include "SynTree/Constant.h" // for Constant
27#include "SynTree/Declaration.h" // for TypeDecl, TypeDecl::Data, Declarati...
28#include "SynTree/Expression.h" // for TypeExpr, Expression, ConstantExpr
29#include "SynTree/Mutator.h" // for Mutator
30#include "SynTree/Type.h" // for Type, TypeInstType, FunctionType
31#include "SynTree/Visitor.h" // for Visitor
32#include "Tuples/Tuples.h" // for isTtype
33#include "TypeEnvironment.h" // for EqvClass, AssertionSet, OpenVarSet
34#include "Unify.h"
35#include "typeops.h" // for flatten, occurs, commonType
36
37namespace SymTab {
38class Indexer;
39} // namespace SymTab
40
41// #define DEBUG
42
43namespace ResolvExpr {
44
45 class Unify : public Visitor {
46 public:
47 Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
48
49 bool get_result() const { return result; }
50 private:
51 virtual void visit(VoidType *voidType);
52 virtual void visit(BasicType *basicType);
53 virtual void visit(PointerType *pointerType);
54 virtual void visit(ArrayType *arrayType);
55 virtual void visit(FunctionType *functionType);
56 virtual void visit(StructInstType *aggregateUseType);
57 virtual void visit(UnionInstType *aggregateUseType);
58 virtual void visit(EnumInstType *aggregateUseType);
59 virtual void visit(TraitInstType *aggregateUseType);
60 virtual void visit(TypeInstType *aggregateUseType);
61 virtual void visit(TupleType *tupleType);
62 virtual void visit(VarArgsType *varArgsType);
63 virtual void visit(ZeroType *zeroType);
64 virtual void visit(OneType *oneType);
65
66 template< typename RefType > void handleRefType( RefType *inst, Type *other );
67 template< typename RefType > void handleGenericRefType( RefType *inst, Type *other );
68
69 bool result;
70 Type *type2; // inherited
71 TypeEnvironment &env;
72 AssertionSet &needAssertions;
73 AssertionSet &haveAssertions;
74 const OpenVarSet &openVars;
75 WidenMode widenMode;
76 const SymTab::Indexer &indexer;
77 };
78
79 /// Attempts an inexact unification of type1 and type2.
80 /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers)
81 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common );
82 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer );
83
84 bool typesCompatible( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
85 TypeEnvironment newEnv;
86 OpenVarSet openVars, closedVars; // added closedVars
87 AssertionSet needAssertions, haveAssertions;
88 Type *newFirst = first->clone(), *newSecond = second->clone();
89 env.apply( newFirst );
90 env.apply( newSecond );
91
92 // do we need to do this? Seems like we do, types should be able to be compatible if they
93 // have free variables that can unify
94 findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false );
95 findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true );
96
97 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
98 delete newFirst;
99 delete newSecond;
100 return result;
101 }
102
103 bool typesCompatibleIgnoreQualifiers( Type *first, Type *second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
104 TypeEnvironment newEnv;
105 OpenVarSet openVars;
106 AssertionSet needAssertions, haveAssertions;
107 Type *newFirst = first->clone(), *newSecond = second->clone();
108 env.apply( newFirst );
109 env.apply( newSecond );
110 newFirst->get_qualifiers() = Type::Qualifiers();
111 newSecond->get_qualifiers() = Type::Qualifiers();
112/// std::cerr << "first is ";
113/// first->print( std::cerr );
114/// std::cerr << std::endl << "second is ";
115/// second->print( std::cerr );
116/// std::cerr << std::endl << "newFirst is ";
117/// newFirst->print( std::cerr );
118/// std::cerr << std::endl << "newSecond is ";
119/// newSecond->print( std::cerr );
120/// std::cerr << std::endl;
121 bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
122 delete newFirst;
123 delete newSecond;
124 return result;
125 }
126
127 bool isFtype( Type *type ) {
128 if ( dynamic_cast< FunctionType* >( type ) ) {
129 return true;
130 } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( type ) ) {
131 return typeInst->get_isFtype();
132 } // if
133 return false;
134 }
135
136 bool tyVarCompatible( const TypeDecl::Data & data, Type *type ) {
137 switch ( data.kind ) {
138 case TypeDecl::Any:
139 case TypeDecl::Dtype:
140 // to bind to an object type variable, the type must not be a function type.
141 // if the type variable is specified to be a complete type then the incoming
142 // type must also be complete
143 // xxx - should this also check that type is not a tuple type and that it's not a ttype?
144 return ! isFtype( type ) && (! data.isComplete || type->isComplete() );
145 case TypeDecl::Ftype:
146 return isFtype( type );
147 case TypeDecl::Ttype:
148 // ttype unifies with any tuple type
149 return dynamic_cast< TupleType * >( type ) || Tuples::isTtype( type );
150 } // switch
151 return false;
152 }
153
154 bool bindVar( TypeInstType *typeInst, Type *other, const TypeDecl::Data & data, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
155 OpenVarSet::const_iterator tyvar = openVars.find( typeInst->get_name() );
156 assert( tyvar != openVars.end() );
157 if ( ! tyVarCompatible( tyvar->second, other ) ) {
158 return false;
159 } // if
160 if ( occurs( other, typeInst->get_name(), env ) ) {
161 return false;
162 } // if
163 EqvClass curClass;
164 if ( env.lookup( typeInst->get_name(), curClass ) ) {
165 if ( curClass.type ) {
166 Type *common = 0;
167 // attempt to unify equivalence class type (which has qualifiers stripped, so they must be restored) with the type to bind to
168 std::auto_ptr< Type > newType( curClass.type->clone() );
169 newType->get_qualifiers() = typeInst->get_qualifiers();
170 if ( unifyInexact( newType.get(), other, env, needAssertions, haveAssertions, openVars, widenMode & WidenMode( curClass.allowWidening, true ), indexer, common ) ) {
171 if ( common ) {
172 common->get_qualifiers() = Type::Qualifiers();
173 delete curClass.type;
174 curClass.type = common;
175 env.add( curClass );
176 } // if
177 return true;
178 } else {
179 return false;
180 } // if
181 } else {
182 curClass.type = other->clone();
183 curClass.type->get_qualifiers() = Type::Qualifiers();
184 curClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
185 env.add( curClass );
186 } // if
187 } else {
188 EqvClass newClass;
189 newClass.vars.insert( typeInst->get_name() );
190 newClass.type = other->clone();
191 newClass.type->get_qualifiers() = Type::Qualifiers();
192 newClass.allowWidening = widenMode.widenFirst && widenMode.widenSecond;
193 newClass.data = data;
194 env.add( newClass );
195 } // if
196 return true;
197 }
198
199 bool bindVarToVar( TypeInstType *var1, TypeInstType *var2, const TypeDecl::Data & data, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
200 bool result = true;
201 EqvClass class1, class2;
202 bool hasClass1 = false, hasClass2 = false;
203 bool widen1 = false, widen2 = false;
204 Type *type1 = 0, *type2 = 0;
205
206 if ( env.lookup( var1->get_name(), class1 ) ) {
207 hasClass1 = true;
208 if ( class1.type ) {
209 if ( occurs( class1.type, var2->get_name(), env ) ) {
210 return false;
211 } // if
212 type1 = class1.type->clone();
213 } // if
214 widen1 = widenMode.widenFirst && class1.allowWidening;
215 } // if
216 if ( env.lookup( var2->get_name(), class2 ) ) {
217 hasClass2 = true;
218 if ( class2.type ) {
219 if ( occurs( class2.type, var1->get_name(), env ) ) {
220 return false;
221 } // if
222 type2 = class2.type->clone();
223 } // if
224 widen2 = widenMode.widenSecond && class2.allowWidening;
225 } // if
226
227 if ( type1 && type2 ) {
228// std::cerr << "has type1 && type2" << std::endl;
229 WidenMode newWidenMode ( widen1, widen2 );
230 Type *common = 0;
231 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, newWidenMode, indexer, common ) ) {
232 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
233 class1.allowWidening = widen1 && widen2;
234 if ( common ) {
235 common->get_qualifiers() = Type::Qualifiers();
236 delete class1.type;
237 class1.type = common;
238 } // if
239 env.add( class1 );
240 } else {
241 result = false;
242 } // if
243 } else if ( hasClass1 && hasClass2 ) {
244 if ( type1 ) {
245 class1.vars.insert( class2.vars.begin(), class2.vars.end() );
246 class1.allowWidening = widen1;
247 env.add( class1 );
248 } else {
249 class2.vars.insert( class1.vars.begin(), class1.vars.end() );
250 class2.allowWidening = widen2;
251 env.add( class2 );
252 } // if
253 } else if ( hasClass1 ) {
254 class1.vars.insert( var2->get_name() );
255 class1.allowWidening = widen1;
256 env.add( class1 );
257 } else if ( hasClass2 ) {
258 class2.vars.insert( var1->get_name() );
259 class2.allowWidening = widen2;
260 env.add( class2 );
261 } else {
262 EqvClass newClass;
263 newClass.vars.insert( var1->get_name() );
264 newClass.vars.insert( var2->get_name() );
265 newClass.allowWidening = widen1 && widen2;
266 newClass.data = data;
267 env.add( newClass );
268 } // if
269 delete type1;
270 delete type2;
271 return result;
272 }
273
274 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
275 OpenVarSet closedVars;
276 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
277 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
278 Type *commonType = 0;
279 if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) {
280 if ( commonType ) {
281 delete commonType;
282 } // if
283 return true;
284 } else {
285 return false;
286 } // if
287 }
288
289 bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) {
290 OpenVarSet closedVars;
291 findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false );
292 findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true );
293 return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType );
294 }
295
296 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer ) {
297#ifdef DEBUG
298 TypeEnvironment debugEnv( env );
299#endif
300 if ( type1->get_qualifiers() != type2->get_qualifiers() ) {
301 return false;
302 }
303
304 bool result;
305 TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 );
306 TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 );
307 OpenVarSet::const_iterator entry1, entry2;
308 if ( var1 ) {
309 entry1 = openVars.find( var1->get_name() );
310 } // if
311 if ( var2 ) {
312 entry2 = openVars.find( var2->get_name() );
313 } // if
314 bool isopen1 = var1 && ( entry1 != openVars.end() );
315 bool isopen2 = var2 && ( entry2 != openVars.end() );
316
317 if ( isopen1 && isopen2 && entry1->second == entry2->second ) {
318 result = bindVarToVar( var1, var2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
319 } else if ( isopen1 ) {
320 result = bindVar( var1, type2, entry1->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
321 } else if ( isopen2 ) {
322 result = bindVar( var2, type1, entry2->second, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
323 } else {
324 Unify comparator( type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer );
325 type1->accept( comparator );
326 result = comparator.get_result();
327 } // if
328#ifdef DEBUG
329 std::cerr << "============ unifyExact" << std::endl;
330 std::cerr << "type1 is ";
331 type1->print( std::cerr );
332 std::cerr << std::endl << "type2 is ";
333 type2->print( std::cerr );
334 std::cerr << std::endl << "openVars are ";
335 printOpenVarSet( openVars, std::cerr, 8 );
336 std::cerr << std::endl << "input env is " << std::endl;
337 debugEnv.print( std::cerr, 8 );
338 std::cerr << std::endl << "result env is " << std::endl;
339 env.print( std::cerr, 8 );
340 std::cerr << "result is " << result << std::endl;
341#endif
342 return result;
343 }
344
345 bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
346 return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
347 }
348
349 bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer, Type *&common ) {
350 Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers();
351 type1->get_qualifiers() = Type::Qualifiers();
352 type2->get_qualifiers() = Type::Qualifiers();
353 bool result;
354#ifdef DEBUG
355 std::cerr << "unifyInexact type 1 is ";
356 type1->print( std::cerr );
357 std::cerr << " type 2 is ";
358 type2->print( std::cerr );
359 std::cerr << std::endl;
360#endif
361 if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widenMode, indexer ) ) {
362#ifdef DEBUG
363 std::cerr << "unifyInexact: no exact unification found" << std::endl;
364#endif
365 if ( ( common = commonType( type1, type2, widenMode.widenFirst, widenMode.widenSecond, indexer, env, openVars ) ) ) {
366 common->get_qualifiers() = tq1 | tq2;
367#ifdef DEBUG
368 std::cerr << "unifyInexact: common type is ";
369 common->print( std::cerr );
370 std::cerr << std::endl;
371#endif
372 result = true;
373 } else {
374#ifdef DEBUG
375 std::cerr << "unifyInexact: no common type found" << std::endl;
376#endif
377 result = false;
378 } // if
379 } else {
380 if ( tq1 != tq2 ) {
381 if ( ( tq1 > tq2 || widenMode.widenFirst ) && ( tq2 > tq1 || widenMode.widenSecond ) ) {
382 common = type1->clone();
383 common->get_qualifiers() = tq1 | tq2;
384 result = true;
385 } else {
386 result = false;
387 } // if
388 } else {
389 result = true;
390 } // if
391 } // if
392 type1->get_qualifiers() = tq1;
393 type2->get_qualifiers() = tq2;
394 return result;
395 }
396
397 Unify::Unify( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widenMode, const SymTab::Indexer &indexer )
398 : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widenMode( widenMode ), indexer( indexer ) {
399 }
400
401 void Unify::visit( __attribute__((unused)) VoidType *voidType) {
402 result = dynamic_cast< VoidType* >( type2 );
403 }
404
405 void Unify::visit(BasicType *basicType) {
406 if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) {
407 result = basicType->get_kind() == otherBasic->get_kind();
408 } // if
409 }
410
411 void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) {
412/// std::cerr << "assertion set is" << std::endl;
413/// printAssertionSet( assertions, std::cerr, 8 );
414/// std::cerr << "looking for ";
415/// assert->print( std::cerr );
416/// std::cerr << std::endl;
417 AssertionSet::iterator i = assertions.find( assert );
418 if ( i != assertions.end() ) {
419/// std::cerr << "found it!" << std::endl;
420 i->second.isUsed = true;
421 } // if
422 }
423
424 void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) {
425 for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) {
426 for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) {
427 markAssertionSet( assertion1, *assert );
428 markAssertionSet( assertion2, *assert );
429 } // for
430 } // for
431 }
432
433 void Unify::visit(PointerType *pointerType) {
434 if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) {
435 result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
436 markAssertions( haveAssertions, needAssertions, pointerType );
437 markAssertions( haveAssertions, needAssertions, otherPointer );
438 } // if
439 }
440
441 void Unify::visit(ArrayType *arrayType) {
442 ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 );
443 // to unify, array types must both be VLA or both not VLA
444 // and must both have a dimension expression or not have a dimension
445 if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) {
446
447 // not positive this is correct in all cases, but it's needed for typedefs
448 if ( arrayType->get_isVarLen() || otherArray->get_isVarLen() ) {
449 return;
450 }
451
452 if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() &&
453 arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) {
454 ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
455 ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() );
456 // see C11 Reference Manual 6.7.6.2.6
457 // two array types with size specifiers that are integer constant expressions are
458 // compatible if both size specifiers have the same constant value
459 if ( ce1 && ce2 ) {
460 Constant * c1 = ce1->get_constant();
461 Constant * c2 = ce2->get_constant();
462
463 if ( c1->get_value() != c2->get_value() ) {
464 // does not unify if the dimension is different
465 return;
466 }
467 }
468 }
469
470 result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
471 } // if
472 }
473
474 template< typename Iterator, typename Func >
475 std::unique_ptr<Type> combineTypes( Iterator begin, Iterator end, Func & toType ) {
476 std::list< Type * > types;
477 for ( ; begin != end; ++begin ) {
478 // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple
479 flatten( toType( *begin ), back_inserter( types ) );
480 }
481 return std::unique_ptr<Type>( new TupleType( Type::Qualifiers(), types ) );
482 }
483
484 template< typename Iterator1, typename Iterator2 >
485 bool unifyDeclList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
486 auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); };
487 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
488 Type * t1 = (*list1Begin)->get_type();
489 Type * t2 = (*list2Begin)->get_type();
490 bool isTtype1 = Tuples::isTtype( t1 );
491 bool isTtype2 = Tuples::isTtype( t2 );
492 // xxx - assumes ttype must be last parameter
493 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
494 if ( isTtype1 && ! isTtype2 ) {
495 // combine all of the things in list2, then unify
496 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
497 } else if ( isTtype2 && ! isTtype1 ) {
498 // combine all of the things in list1, then unify
499 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
500 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
501 return false;
502 } // if
503 } // for
504 // 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
505 if ( list1Begin != list1End ) {
506 // try unifying empty tuple type with ttype
507 Type * t1 = (*list1Begin)->get_type();
508 if ( Tuples::isTtype( t1 ) ) {
509 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
510 } else return false;
511 } else if ( list2Begin != list2End ) {
512 // try unifying empty tuple type with ttype
513 Type * t2 = (*list2Begin)->get_type();
514 if ( Tuples::isTtype( t2 ) ) {
515 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
516 } else return false;
517 } else {
518 return true;
519 } // if
520 }
521
522 /// Finds ttypes and replaces them with their expansion, if known.
523 /// This needs to be done so that satisfying ttype assertions is easier.
524 /// If this isn't done then argument lists can have wildly different
525 /// size and structure, when they should be compatible.
526 struct TtypeExpander : public Mutator {
527 TypeEnvironment & env;
528 TtypeExpander( TypeEnvironment & env ) : env( env ) {}
529 Type * mutate( TypeInstType * typeInst ) {
530 EqvClass eqvClass;
531 if ( env.lookup( typeInst->get_name(), eqvClass ) ) {
532 if ( eqvClass.data.kind == TypeDecl::Ttype ) {
533 // expand ttype parameter into its actual type
534 if ( eqvClass.type ) {
535 delete typeInst;
536 return eqvClass.type->clone();
537 }
538 }
539 }
540 return typeInst;
541 }
542 };
543
544 /// flattens a list of declarations, so that each tuple type has a single declaration.
545 /// makes use of TtypeExpander to ensure ttypes are flat as well.
546 void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) {
547 dst.clear();
548 for ( DeclarationWithType * dcl : src ) {
549 TtypeExpander expander( env );
550 dcl->acceptMutator( expander );
551 std::list< Type * > types;
552 flatten( dcl->get_type(), back_inserter( types ) );
553 for ( Type * t : types ) {
554 dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) );
555 }
556 delete dcl;
557 }
558 }
559
560 void Unify::visit(FunctionType *functionType) {
561 FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 );
562 if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) {
563 // flatten the parameter lists for both functions so that tuple structure
564 // doesn't affect unification. Must be a clone so that the types don't change.
565 std::unique_ptr<FunctionType> flatFunc( functionType->clone() );
566 std::unique_ptr<FunctionType> flatOther( otherFunction->clone() );
567 flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env );
568 flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env );
569
570 // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors
571 if ( (flatFunc->get_parameters().size() == flatOther->get_parameters().size() && flatFunc->get_returnVals().size() == flatOther->get_returnVals().size()) || flatFunc->isTtype() || flatOther->isTtype() ) {
572 if ( unifyDeclList( flatFunc->get_parameters().begin(), flatFunc->get_parameters().end(), flatOther->get_parameters().begin(), flatOther->get_parameters().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
573 if ( unifyDeclList( flatFunc->get_returnVals().begin(), flatFunc->get_returnVals().end(), flatOther->get_returnVals().begin(), flatOther->get_returnVals().end(), env, needAssertions, haveAssertions, openVars, indexer ) ) {
574
575 // the original types must be used in mark assertions, since pointer comparisons are used
576 markAssertions( haveAssertions, needAssertions, functionType );
577 markAssertions( haveAssertions, needAssertions, otherFunction );
578
579 result = true;
580 } // if
581 } // if
582 } // if
583 } // if
584 }
585
586 template< typename RefType >
587 void Unify::handleRefType( RefType *inst, Type *other ) {
588 // check that other type is compatible and named the same
589 RefType *otherStruct = dynamic_cast< RefType* >( other );
590 result = otherStruct && inst->get_name() == otherStruct->get_name();
591 }
592
593 template< typename RefType >
594 void Unify::handleGenericRefType( RefType *inst, Type *other ) {
595 // Check that other type is compatible and named the same
596 handleRefType( inst, other );
597 if ( ! result ) return;
598 // Check that parameters of types unify, if any
599 std::list< Expression* > params = inst->get_parameters();
600 std::list< Expression* > otherParams = ((RefType*)other)->get_parameters();
601
602 std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin();
603 for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) {
604 TypeExpr *param = dynamic_cast< TypeExpr* >(*it);
605 assertf(param, "Aggregate parameters should be type expressions");
606 TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt);
607 assertf(otherParam, "Aggregate parameters should be type expressions");
608
609 Type* paramTy = param->get_type();
610 Type* otherParamTy = otherParam->get_type();
611
612 bool tupleParam = Tuples::isTtype( paramTy );
613 bool otherTupleParam = Tuples::isTtype( otherParamTy );
614
615 if ( tupleParam && otherTupleParam ) {
616 ++it; ++jt; // skip ttype parameters for break
617 } else if ( tupleParam ) {
618 // bundle other parameters into tuple to match
619 std::list< Type * > binderTypes;
620
621 do {
622 binderTypes.push_back( otherParam->get_type()->clone() );
623 ++jt;
624
625 if ( jt == otherParams.end() ) break;
626
627 otherParam = dynamic_cast< TypeExpr* >(*jt);
628 assertf(otherParam, "Aggregate parameters should be type expressions");
629 } while (true);
630
631 otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes };
632 ++it; // skip ttype parameter for break
633 } else if ( otherTupleParam ) {
634 // bundle parameters into tuple to match other
635 std::list< Type * > binderTypes;
636
637 do {
638 binderTypes.push_back( param->get_type()->clone() );
639 ++it;
640
641 if ( it == params.end() ) break;
642
643 param = dynamic_cast< TypeExpr* >(*it);
644 assertf(param, "Aggregate parameters should be type expressions");
645 } while (true);
646
647 paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes };
648 ++jt; // skip ttype parameter for break
649 }
650
651 if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) {
652 result = false;
653 return;
654 }
655
656 // ttype parameter should be last
657 if ( tupleParam || otherTupleParam ) break;
658 }
659 result = ( it == params.end() && jt == otherParams.end() );
660 }
661
662 void Unify::visit(StructInstType *structInst) {
663 handleGenericRefType( structInst, type2 );
664 }
665
666 void Unify::visit(UnionInstType *unionInst) {
667 handleGenericRefType( unionInst, type2 );
668 }
669
670 void Unify::visit(EnumInstType *enumInst) {
671 handleRefType( enumInst, type2 );
672 }
673
674 void Unify::visit(TraitInstType *contextInst) {
675 handleRefType( contextInst, type2 );
676 }
677
678 void Unify::visit(TypeInstType *typeInst) {
679 assert( openVars.find( typeInst->get_name() ) == openVars.end() );
680 TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 );
681 if ( otherInst && typeInst->get_name() == otherInst->get_name() ) {
682 result = true;
683/// } else {
684/// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() );
685/// if ( nt ) {
686/// TypeDecl *type = dynamic_cast< TypeDecl* >( nt );
687/// assert( type );
688/// if ( type->get_base() ) {
689/// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
690/// }
691/// }
692 } // if
693 }
694
695 template< typename Iterator1, typename Iterator2 >
696 bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) {
697 auto get_type = [](Type * t) { return t; };
698 for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) {
699 Type * t1 = *list1Begin;
700 Type * t2 = *list2Begin;
701 bool isTtype1 = Tuples::isTtype( t1 );
702 bool isTtype2 = Tuples::isTtype( t2 );
703 // xxx - assumes ttype must be last parameter
704 // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases.
705 if ( isTtype1 && ! isTtype2 ) {
706 // combine all of the things in list2, then unify
707 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
708 } else if ( isTtype2 && ! isTtype1 ) {
709 // combine all of the things in list1, then unify
710 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
711 } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) {
712 return false;
713 } // if
714
715 } // for
716 if ( list1Begin != list1End ) {
717 // try unifying empty tuple type with ttype
718 Type * t1 = *list1Begin;
719 if ( Tuples::isTtype( t1 ) ) {
720 return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
721 } else return false;
722 } else if ( list2Begin != list2End ) {
723 // try unifying empty tuple type with ttype
724 Type * t2 = *list2Begin;
725 if ( Tuples::isTtype( t2 ) ) {
726 return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer );
727 } else return false;
728 } else {
729 return true;
730 } // if
731 }
732
733 void Unify::visit(TupleType *tupleType) {
734 if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) {
735 std::unique_ptr<TupleType> flat1( tupleType->clone() );
736 std::unique_ptr<TupleType> flat2( otherTuple->clone() );
737 std::list<Type *> types1, types2;
738
739 TtypeExpander expander( env );
740 flat1->acceptMutator( expander );
741 flat2->acceptMutator( expander );
742
743 flatten( flat1.get(), back_inserter( types1 ) );
744 flatten( flat2.get(), back_inserter( types2 ) );
745
746 result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer );
747 } // if
748 }
749
750 void Unify::visit( __attribute__((unused)) VarArgsType *varArgsType ) {
751 result = dynamic_cast< VarArgsType* >( type2 );
752 }
753
754 void Unify::visit( __attribute__((unused)) ZeroType *zeroType ) {
755 result = dynamic_cast< ZeroType* >( type2 );
756 }
757
758 void Unify::visit( __attribute__((unused)) OneType *oneType ) {
759 result = dynamic_cast< OneType* >( type2 );
760 }
761
762 // xxx - compute once and store in the FunctionType?
763 Type * extractResultType( FunctionType * function ) {
764 if ( function->get_returnVals().size() == 0 ) {
765 return new VoidType( Type::Qualifiers() );
766 } else if ( function->get_returnVals().size() == 1 ) {
767 return function->get_returnVals().front()->get_type()->clone();
768 } else {
769 std::list< Type * > types;
770 for ( DeclarationWithType * decl : function->get_returnVals() ) {
771 types.push_back( decl->get_type()->clone() );
772 } // for
773 return new TupleType( Type::Qualifiers(), types );
774 }
775 }
776} // namespace ResolvExpr
777
778// Local Variables: //
779// tab-width: 4 //
780// mode: c++ //
781// compile-command: "make install" //
782// End: //
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