source: src/ResolvExpr/TypeEnvironment.cc@ 58688bf

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 58688bf was 7215000, checked in by Thierry Delisle <tdelisle@…>, 6 years ago

Added flag to disable non-deteministic parts of the output when testing
  • Property mode set to 100644
File size: 16.4 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// TypeEnvironment.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sun May 17 12:19:47 2015
11// Last Modified By : Andrew Beach
12// Last Modified On : Fri Jun 18 14:27:00 2019
13// Update Count : 5
14//
15
16#include <cassert> // for assert
17#include <algorithm> // for copy, set_intersection
18#include <iterator> // for ostream_iterator, insert_iterator
19#include <memory> // for unique_ptr
20#include <utility> // for pair, move
21
22#include "CompilationState.h" // for deterministic_output
23#include "Common/utility.h" // for maybeClone
24#include "SynTree/Type.h" // for Type, FunctionType, Type::Fora...
25#include "SynTree/TypeSubstitution.h" // for TypeSubstitution
26#include "Tuples/Tuples.h" // for isTtype
27#include "TypeEnvironment.h"
28#include "typeops.h" // for occurs
29#include "Unify.h" // for unifyInexact
30
31namespace ResolvExpr {
32 void printAssertionSet( const AssertionSet &assertions, std::ostream &os, int indent ) {
33 for ( AssertionSet::const_iterator i = assertions.begin(); i != assertions.end(); ++i ) {
34 i->first->print( os, indent );
35 if ( i->second.isUsed ) {
36 os << "(used)";
37 } else {
38 os << "(not used)";
39 } // if
40 } // for
41 }
42
43 void printOpenVarSet( const OpenVarSet &openVars, std::ostream &os, int indent ) {
44 os << std::string( indent, ' ' );
45 for ( OpenVarSet::const_iterator i = openVars.begin(); i != openVars.end(); ++i ) {
46 os << i->first << "(" << i->second << ") ";
47 } // for
48 }
49
50 void EqvClass::initialize( const EqvClass &src, EqvClass &dest ) {
51 initialize( src, dest, src.type );
52 }
53
54 void EqvClass::initialize( const EqvClass &src, EqvClass &dest, const Type *ty ) {
55 dest.vars = src.vars;
56 dest.type = maybeClone( ty );
57 dest.allowWidening = src.allowWidening;
58 dest.data = src.data;
59 }
60
61 EqvClass::EqvClass() : type( nullptr ), allowWidening( true ) {
62 }
63
64 EqvClass::EqvClass( const EqvClass &other ) {
65 initialize( other, *this );
66 }
67
68 EqvClass::EqvClass( const EqvClass &other, const Type *ty ) {
69 initialize( other, *this, ty );
70 }
71
72 EqvClass::EqvClass( EqvClass &&other )
73 : vars{std::move(other.vars)}, type{other.type},
74 allowWidening{std::move(other.allowWidening)}, data{std::move(other.data)} {
75 other.type = nullptr;
76 }
77
78 EqvClass &EqvClass::operator=( const EqvClass &other ) {
79 if ( this == &other ) return *this;
80 delete type;
81 initialize( other, *this );
82 return *this;
83 }
84
85 EqvClass &EqvClass::operator=( EqvClass &&other ) {
86 if ( this == &other ) return *this;
87 delete type;
88
89 vars = std::move(other.vars);
90 type = other.type;
91 other.type = nullptr;
92 allowWidening = std::move(other.allowWidening);
93 data = std::move(other.data);
94
95 return *this;
96 }
97
98 EqvClass::~EqvClass() {
99 delete type;
100 }
101
102 void EqvClass::set_type( Type* ty ) {
103 if ( ty == type ) return;
104 delete type;
105 type = ty;
106 }
107
108 void EqvClass::print( std::ostream &os, Indenter indent ) const {
109 if( !deterministic_output ) {
110 os << "( ";
111 std::copy( vars.begin(), vars.end(), std::ostream_iterator< std::string >( os, " " ) );
112 os << ")";
113 }
114 if ( type ) {
115 os << " -> ";
116 type->print( os, indent+1 );
117 } // if
118 if ( ! allowWidening ) {
119 os << " (no widening)";
120 } // if
121 os << std::endl;
122 }
123
124 const EqvClass* TypeEnvironment::lookup( const std::string &var ) const {
125 for ( ClassList::const_iterator i = env.begin(); i != env.end(); ++i ) {
126 if ( i->vars.find( var ) != i->vars.end() ) return &*i;
127 } // for
128 return nullptr;
129 }
130
131 /// Removes any class from env that intersects eqvClass
132 void filterOverlappingClasses( std::list<EqvClass> &env, const EqvClass &eqvClass ) {
133 for ( auto i = env.begin(); i != env.end(); ) {
134 auto next = i;
135 ++next;
136 std::set<std::string> intersection;
137 std::set_intersection( i->vars.begin(), i->vars.end(), eqvClass.vars.begin(), eqvClass.vars.end(),
138 std::inserter( intersection, intersection.begin() ) );
139 if ( ! intersection.empty() ) { env.erase( i ); }
140 i = next;
141 }
142 }
143
144 void TypeEnvironment::add( EqvClass &&eqvClass ) {
145 filterOverlappingClasses( env, eqvClass );
146 env.push_back( std::move(eqvClass) );
147 }
148
149 void TypeEnvironment::add( const Type::ForallList &tyDecls ) {
150 for ( Type::ForallList::const_iterator i = tyDecls.begin(); i != tyDecls.end(); ++i ) {
151 EqvClass newClass;
152 newClass.vars.insert( (*i)->get_name() );
153 newClass.data = TypeDecl::Data{ (*i) };
154 env.push_back( std::move(newClass) );
155 } // for
156 }
157
158 void TypeEnvironment::add( const TypeSubstitution & sub ) {
159 EqvClass newClass;
160 for ( auto p : sub ) {
161 newClass.vars.insert( p.first );
162 newClass.type = p.second->clone();
163 newClass.allowWidening = false;
164 // Minimal assumptions. Not technically correct, but might be good enough, and
165 // is the best we can do at the moment since information is lost in the
166 // transition to TypeSubstitution
167 newClass.data = TypeDecl::Data{ TypeDecl::Dtype, false };
168 add( std::move(newClass) );
169 }
170 }
171
172 void TypeEnvironment::makeSubstitution( TypeSubstitution &sub ) const {
173 for ( ClassList::const_iterator theClass = env.begin(); theClass != env.end(); ++theClass ) {
174 for ( std::set< std::string >::const_iterator theVar = theClass->vars.begin(); theVar != theClass->vars.end(); ++theVar ) {
175 if ( theClass->type ) {
176 sub.add( *theVar, theClass->type );
177 } else if ( theVar != theClass->vars.begin() ) {
178 TypeInstType *newTypeInst = new TypeInstType( Type::Qualifiers(), *theClass->vars.begin(), theClass->data.kind == TypeDecl::Ftype );
179 sub.add( *theVar, newTypeInst );
180 delete newTypeInst;
181 } // if
182 } // for
183 } // for
184 sub.normalize();
185 }
186
187 void TypeEnvironment::print( std::ostream &os, Indenter indent ) const {
188 for ( const EqvClass & theClass : env ) {
189 theClass.print( os, indent );
190 } // for
191 }
192
193 TypeEnvironment::ClassList::iterator TypeEnvironment::internal_lookup( const std::string &var ) {
194 for ( ClassList::iterator i = env.begin(); i != env.end(); ++i ) {
195 if ( i->vars.count( var ) ) return i;
196 } // for
197 return env.end();
198 }
199
200 void TypeEnvironment::simpleCombine( const TypeEnvironment &second ) {
201 env.insert( env.end(), second.env.begin(), second.env.end() );
202 }
203
204 // xxx -- this should maybe be worrying about iterator invalidation (see resolv-proto)
205 bool TypeEnvironment::mergeBound( EqvClass& to, const EqvClass& from, OpenVarSet& openVars, const SymTab::Indexer& indexer ) {
206 if ( from.type ) {
207 if ( to.type ) {
208 // attempt to unify bound types
209 std::unique_ptr<Type> toType{ to.type->clone() }, fromType{ from.type->clone() };
210 WidenMode widen{ to.allowWidening, from.allowWidening };
211 Type* common = nullptr;
212 AssertionSet need, have;
213 if ( unifyInexact( toType.get(), fromType.get(), *this, need, have, openVars, widen, indexer, common ) ) {
214 // unifies, set common type if necessary
215 if ( common ) {
216 common->get_qualifiers() = Type::Qualifiers{};
217 to.set_type( common );
218 }
219 } else return false; // cannot unify
220 } else {
221 to.type = from.type->clone();
222 }
223 }
224
225 // unify widening if matches
226 to.allowWidening &= from.allowWidening;
227 return true;
228 }
229
230 // xxx -- this should maybe be worrying about iterator invalidation (see resolv-proto)
231 bool TypeEnvironment::mergeClasses( TypeEnvironment::ClassList::iterator to, TypeEnvironment::ClassList::iterator from, OpenVarSet& openVars, const SymTab::Indexer& indexer ) {
232 EqvClass& r = *to;
233 EqvClass& s = *from;
234
235 // ensure bounds match
236 if ( ! mergeBound( r, s, openVars, indexer ) ) return false;
237
238 // check safely bindable
239 if ( r.type && occursIn( r.type, s.vars.begin(), s.vars.end(), *this ) ) return false;
240
241 // merge classes in
242 r.vars.insert( s.vars.begin(), s.vars.end() );
243 r.allowWidening &= s.allowWidening;
244 env.erase( from );
245
246 return true;
247 }
248
249 bool TypeEnvironment::combine( const TypeEnvironment& o, OpenVarSet& openVars, const SymTab::Indexer& indexer ) {
250 // short-circuit easy cases
251 if ( o.isEmpty() ) return true;
252 if ( isEmpty() ) {
253 simpleCombine( o );
254 return true;
255 }
256
257 // merge classes
258 for ( auto ct = o.env.begin(); ct != o.env.end(); ++ct ) {
259 const EqvClass& c = *ct;
260
261 // typeclass in local environment bound to c
262 auto rt = env.end();
263
264 // look for first existing bound variable
265 auto vt = c.vars.begin();
266 for ( ; vt != c.vars.end(); ++vt ) {
267 rt = internal_lookup( *vt );
268 if ( rt != env.end() ) break;
269 }
270
271 if ( rt != env.end() ) { // c needs to be merged into *rt
272 EqvClass& r = *rt;
273 // merge bindings
274 if ( ! mergeBound( r, c, openVars, indexer ) ) return false;
275 // merge previous unbound variables into this class, checking occurs if needed
276 if ( r.type ) for ( auto ut = c.vars.begin(); ut != vt; ++ut ) {
277 if ( occurs( r.type, *ut, *this ) ) return false;
278 r.vars.insert( *ut );
279 } else { r.vars.insert( c.vars.begin(), vt ); }
280 // merge subsequent variables into this class (skipping *vt, already there)
281 while ( ++vt != c.vars.end() ) {
282 auto st = internal_lookup( *vt );
283 if ( st == env.end() ) {
284 // unbound, safe to add if passes occurs
285 if ( r.type && occurs( r.type, *vt, *this ) ) return false;
286 r.vars.insert( *vt );
287 } else if ( st != rt ) {
288 // bound, but not to the same class
289 if ( ! mergeClasses( rt, st, openVars, indexer ) ) return false;
290 } // ignore bound into the same class
291 }
292 } else { // no variables in c bound; just copy up
293 env.push_back( c );
294 }
295 }
296
297 // merged all classes
298 return true;
299 }
300
301 void TypeEnvironment::extractOpenVars( OpenVarSet &openVars ) const {
302 for ( ClassList::const_iterator eqvClass = env.begin(); eqvClass != env.end(); ++eqvClass ) {
303 for ( std::set< std::string >::const_iterator var = eqvClass->vars.begin(); var != eqvClass->vars.end(); ++var ) {
304 openVars[ *var ] = eqvClass->data;
305 } // for
306 } // for
307 }
308
309 void TypeEnvironment::addActual( const TypeEnvironment& actualEnv, OpenVarSet& openVars ) {
310 for ( const EqvClass& c : actualEnv ) {
311 EqvClass c2 = c;
312 c2.allowWidening = false;
313 for ( const std::string& var : c2.vars ) {
314 openVars[ var ] = c2.data;
315 }
316 env.push_back( std::move(c2) );
317 }
318 }
319
320 bool isFtype( const Type * type ) {
321 if ( dynamic_cast< const FunctionType * >( type ) ) {
322 return true;
323 } else if ( const TypeInstType *typeInst = dynamic_cast< const TypeInstType * >( type ) ) {
324 return typeInst->get_isFtype();
325 } // if
326 return false;
327 }
328
329 bool tyVarCompatible( const TypeDecl::Data & data, const Type * type ) {
330 switch ( data.kind ) {
331 case TypeDecl::Dtype:
332 // to bind to an object type variable, the type must not be a function type.
333 // if the type variable is specified to be a complete type then the incoming
334 // type must also be complete
335 // xxx - should this also check that type is not a tuple type and that it's not a ttype?
336 return ! isFtype( type ) && (! data.isComplete || type->isComplete() );
337 case TypeDecl::Ftype:
338 return isFtype( type );
339 case TypeDecl::Ttype:
340 // ttype unifies with any tuple type
341 return dynamic_cast< const TupleType * >( type ) || Tuples::isTtype( type );
342 default:
343 assertf(false, "Unhandled tyvar kind: %d", data.kind);
344 } // switch
345 return false;
346 }
347
348 bool TypeEnvironment::bindVar( const TypeInstType *typeInst, Type *bindTo, const TypeDecl::Data & data, AssertionSet &need, AssertionSet &have, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
349
350 // remove references from other, so that type variables can only bind to value types
351 bindTo = bindTo->stripReferences();
352 OpenVarSet::const_iterator tyvar = openVars.find( typeInst->get_name() );
353 assert( tyvar != openVars.end() );
354 if ( ! tyVarCompatible( tyvar->second, bindTo ) ) {
355 return false;
356 } // if
357 if ( occurs( bindTo, typeInst->get_name(), *this ) ) {
358 return false;
359 } // if
360 auto curClass = internal_lookup( typeInst->get_name() );
361 if ( curClass != env.end() ) {
362 if ( curClass->type ) {
363 Type *common = 0;
364 // attempt to unify equivalence class type (which has qualifiers stripped, so they must be restored) with the type to bind to
365 std::unique_ptr< Type > newType( curClass->type->clone() );
366 newType->tq = typeInst->tq;
367 if ( unifyInexact( newType.get(), bindTo, *this, need, have, openVars, widen & WidenMode( curClass->allowWidening, true ), indexer, common ) ) {
368 if ( common ) {
369 common->get_qualifiers() = Type::Qualifiers{};
370 curClass->set_type( common );
371 } // if
372 } else return false;
373 } else {
374 Type* newType = bindTo->clone();
375 newType->get_qualifiers() = Type::Qualifiers{};
376 curClass->set_type( newType );
377 curClass->allowWidening = widen.first && widen.second;
378 } // if
379 } else {
380 EqvClass newClass;
381 newClass.vars.insert( typeInst->get_name() );
382 newClass.type = bindTo->clone();
383 newClass.type->get_qualifiers() = Type::Qualifiers();
384 newClass.allowWidening = widen.first && widen.second;
385 newClass.data = data;
386 env.push_back( std::move(newClass) );
387 } // if
388 return true;
389 }
390
391 bool TypeEnvironment::bindVarToVar( const TypeInstType * var1, const TypeInstType * var2,
392 TypeDecl::Data && data, AssertionSet &need, AssertionSet &have,
393 const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
394
395 auto class1 = internal_lookup( var1->get_name() );
396 auto class2 = internal_lookup( var2->get_name() );
397
398 // exit early if variables already bound together
399 if ( class1 != env.end() && class1 == class2 ) {
400 class1->allowWidening &= widen;
401 return true;
402 }
403
404 bool widen1 = false, widen2 = false;
405 const Type *type1 = nullptr, *type2 = nullptr;
406
407 // check for existing bindings, perform occurs check
408 if ( class1 != env.end() ) {
409 if ( class1->type ) {
410 if ( occurs( class1->type, var2->get_name(), *this ) ) return false;
411 type1 = class1->type;
412 } // if
413 widen1 = widen.first && class1->allowWidening;
414 } // if
415 if ( class2 != env.end() ) {
416 if ( class2->type ) {
417 if ( occurs( class2->type, var1->get_name(), *this ) ) return false;
418 type2 = class2->type;
419 } // if
420 widen2 = widen.second && class2->allowWidening;
421 } // if
422
423 if ( type1 && type2 ) {
424 // both classes bound, merge if bound types can be unified
425 std::unique_ptr<Type> newType1{ type1->clone() }, newType2{ type2->clone() };
426 WidenMode newWidenMode{ widen1, widen2 };
427 Type *common = 0;
428 if ( unifyInexact( newType1.get(), newType2.get(), *this, need, have, openVars, newWidenMode, indexer, common ) ) {
429 class1->vars.insert( class2->vars.begin(), class2->vars.end() );
430 class1->allowWidening = widen1 && widen2;
431 if ( common ) {
432 common->get_qualifiers() = Type::Qualifiers{};
433 class1->set_type( common );
434 }
435 class1->data.isComplete |= data.isComplete;
436 env.erase( class2 );
437 } else return false;
438 } else if ( class1 != env.end() && class2 != env.end() ) {
439 // both classes exist, at least one unbound, merge unconditionally
440 if ( type1 ) {
441 class1->vars.insert( class2->vars.begin(), class2->vars.end() );
442 class1->allowWidening = widen1;
443 class1->data.isComplete |= data.isComplete;
444 env.erase( class2 );
445 } else {
446 class2->vars.insert( class1->vars.begin(), class1->vars.end() );
447 class2->allowWidening = widen2;
448 class2->data.isComplete |= data.isComplete;
449 env.erase( class1 );
450 } // if
451 } else if ( class1 != env.end() ) {
452 // var2 unbound, add to class1
453 class1->vars.insert( var2->get_name() );
454 class1->allowWidening = widen1;
455 class1->data.isComplete |= data.isComplete;
456 } else if ( class2 != env.end() ) {
457 // var1 unbound, add to class2
458 class2->vars.insert( var1->get_name() );
459 class2->allowWidening = widen2;
460 class2->data.isComplete |= data.isComplete;
461 } else {
462 // neither var bound, create new class
463 EqvClass newClass;
464 newClass.vars.insert( var1->get_name() );
465 newClass.vars.insert( var2->get_name() );
466 newClass.allowWidening = widen1 && widen2;
467 newClass.data = data;
468 env.push_back( std::move(newClass) );
469 } // if
470 return true;
471 }
472
473 void TypeEnvironment::forbidWidening() {
474 for ( EqvClass& c : env ) c.allowWidening = false;
475 }
476
477 std::ostream & operator<<( std::ostream & out, const TypeEnvironment & env ) {
478 env.print( out );
479 return out;
480 }
481} // namespace ResolvExpr
482
483// Local Variables: //
484// tab-width: 4 //
485// mode: c++ //
486// compile-command: "make install" //
487// End: //
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