source: src/GenPoly/InstantiateGeneric.cc@ 3bff885

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 3bff885 was e58dfb9, checked in by Aaron Moss <a3moss@…>, 9 years ago

Fix scoping bug with generic type instantiations (thanks Rob!)
  • Property mode set to 100644
File size: 17.1 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2016 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// InstantiateGeneric.cc --
8//
9// Author : Aaron B. Moss
10// Created On : Thu Aug 04 18:33:00 2016
11// Last Modified By : Aaron B. Moss
12// Last Modified On : Thu Aug 04 18:33:00 2016
13// Update Count : 1
14//
15
16#include <cassert>
17#include <list>
18#include <utility>
19#include <vector>
20#include <unordered_map>
21
22#include "InstantiateGeneric.h"
23
24#include "DeclMutator.h"
25#include "GenPoly.h"
26#include "ScopedSet.h"
27#include "PolyMutator.h"
28
29#include "ResolvExpr/typeops.h"
30
31#include "SynTree/Declaration.h"
32#include "SynTree/Expression.h"
33#include "SynTree/Type.h"
34
35#include "Common/ScopedMap.h"
36#include "Common/UniqueName.h"
37#include "Common/utility.h"
38
39namespace GenPoly {
40
41 /// Abstracts type equality for a list of parameter types
42 struct TypeList {
43 TypeList() : params() {}
44 TypeList( const std::list< Type* > &_params ) : params() { cloneAll(_params, params); }
45 TypeList( std::list< Type* > &&_params ) : params( _params ) {}
46
47 TypeList( const TypeList &that ) : params() { cloneAll(that.params, params); }
48 TypeList( TypeList &&that ) : params( std::move( that.params ) ) {}
49
50 /// Extracts types from a list of TypeExpr*
51 TypeList( const std::list< TypeExpr* >& _params ) : params() {
52 for ( std::list< TypeExpr* >::const_iterator param = _params.begin(); param != _params.end(); ++param ) {
53 params.push_back( (*param)->get_type()->clone() );
54 }
55 }
56
57 TypeList& operator= ( const TypeList &that ) {
58 deleteAll( params );
59
60 params.clear();
61 cloneAll( that.params, params );
62
63 return *this;
64 }
65
66 TypeList& operator= ( TypeList &&that ) {
67 deleteAll( params );
68
69 params = std::move( that.params );
70
71 return *this;
72 }
73
74 ~TypeList() { deleteAll( params ); }
75
76 bool operator== ( const TypeList& that ) const {
77 if ( params.size() != that.params.size() ) return false;
78
79 SymTab::Indexer dummy;
80 for ( std::list< Type* >::const_iterator it = params.begin(), jt = that.params.begin(); it != params.end(); ++it, ++jt ) {
81 if ( ! ResolvExpr::typesCompatible( *it, *jt, dummy ) ) return false;
82 }
83 return true;
84 }
85
86 std::list< Type* > params; ///< Instantiation parameters
87 };
88
89 /// Maps a key and a TypeList to the some value, accounting for scope
90 template< typename Key, typename Value >
91 class InstantiationMap {
92 /// Wraps value for a specific (Key, TypeList) combination
93 typedef std::pair< TypeList, Value* > Instantiation;
94 /// List of TypeLists paired with their appropriate values
95 typedef std::vector< Instantiation > ValueList;
96 /// Underlying map type; maps keys to a linear list of corresponding TypeLists and values
97 typedef ScopedMap< Key*, ValueList > InnerMap;
98
99 InnerMap instantiations; ///< instantiations
100
101 public:
102 /// Starts a new scope
103 void beginScope() { instantiations.beginScope(); }
104
105 /// Ends a scope
106 void endScope() { instantiations.endScope(); }
107
108 /// Gets the value for the (key, typeList) pair, returns NULL on none such.
109 Value *lookup( Key *key, const std::list< TypeExpr* >& params ) const {
110 TypeList typeList( params );
111
112 // scan scopes for matches to the key
113 for ( typename InnerMap::const_iterator insts = instantiations.find( key ); insts != instantiations.end(); insts = instantiations.findNext( insts, key ) ) {
114 for ( typename ValueList::const_reverse_iterator inst = insts->second.rbegin(); inst != insts->second.rend(); ++inst ) {
115 if ( inst->first == typeList ) return inst->second;
116 }
117 }
118 // no matching instantiations found
119 return 0;
120 }
121
122 /// Adds a value for a (key, typeList) pair to the current scope
123 void insert( Key *key, const std::list< TypeExpr* > &params, Value *value ) {
124 auto it = instantiations.findAt( instantiations.currentScope(), key );
125 if ( it == instantiations.end() ) {
126 instantiations.insert( key, ValueList{ Instantiation{ TypeList( params ), value } } );
127 } else {
128 it->second.push_back( Instantiation{ TypeList( params ), value } );
129 }
130 }
131 };
132
133 /// Possible options for a given specialization of a generic type
134 enum class genericType {
135 dtypeStatic, ///< Concrete instantiation based solely on {d,f}type-to-void conversions
136 concrete, ///< Concrete instantiation requiring at least one parameter type
137 dynamic ///< No concrete instantiation
138 };
139
140 genericType& operator |= ( genericType& gt, const genericType& ht ) {
141 switch ( gt ) {
142 case genericType::dtypeStatic:
143 gt = ht;
144 break;
145 case genericType::concrete:
146 if ( ht == genericType::dynamic ) { gt = genericType::dynamic; }
147 break;
148 case genericType::dynamic:
149 // nothing possible
150 break;
151 }
152 return gt;
153 }
154
155 // collect the environments of each TypeInstType so that type variables can be replaced
156 // xxx - possibly temporary solution. Access to type environments is required in GenericInstantiator, but it needs to be a DeclMutator which does not provide easy access to the type environments.
157 class EnvFinder final : public GenPoly::PolyMutator {
158 public:
159 using GenPoly::PolyMutator::mutate;
160 virtual Type * mutate( TypeInstType * inst ) override {
161 if ( env ) envMap[inst] = env;
162 return inst;
163 }
164
165 // don't want to associate an environment with TypeInstTypes that occur in function types - this may actually only apply to function types belonging to DeclarationWithTypes (or even just FunctionDecl)?
166 virtual Type * mutate( FunctionType * ftype ) override {
167 return ftype;
168 }
169 std::unordered_map< ReferenceToType *, TypeSubstitution * > envMap;
170 };
171
172 /// Mutator pass that replaces concrete instantiations of generic types with actual struct declarations, scoped appropriately
173 class GenericInstantiator final : public DeclMutator {
174 /// Map of (generic type, parameter list) pairs to concrete type instantiations
175 InstantiationMap< AggregateDecl, AggregateDecl > instantiations;
176 /// Set of types which are dtype-only generic (and therefore have static layout)
177 ScopedSet< AggregateDecl* > dtypeStatics;
178 /// Namer for concrete types
179 UniqueName typeNamer;
180 /// Reference to mapping of environments
181 const std::unordered_map< ReferenceToType *, TypeSubstitution * > & envMap;
182 public:
183 GenericInstantiator( const std::unordered_map< ReferenceToType *, TypeSubstitution * > & envMap ) : DeclMutator(), instantiations(), dtypeStatics(), typeNamer("_conc_"), envMap( envMap ) {}
184
185 using DeclMutator::mutate;
186 virtual Type* mutate( StructInstType *inst ) override;
187 virtual Type* mutate( UnionInstType *inst ) override;
188
189 virtual void doBeginScope() override;
190 virtual void doEndScope() override;
191 private:
192 /// Wrap instantiation lookup for structs
193 StructDecl* lookup( StructInstType *inst, const std::list< TypeExpr* > &typeSubs ) { return (StructDecl*)instantiations.lookup( inst->get_baseStruct(), typeSubs ); }
194 /// Wrap instantiation lookup for unions
195 UnionDecl* lookup( UnionInstType *inst, const std::list< TypeExpr* > &typeSubs ) { return (UnionDecl*)instantiations.lookup( inst->get_baseUnion(), typeSubs ); }
196 /// Wrap instantiation insertion for structs
197 void insert( StructInstType *inst, const std::list< TypeExpr* > &typeSubs, StructDecl *decl ) { instantiations.insert( inst->get_baseStruct(), typeSubs, decl ); }
198 /// Wrap instantiation insertion for unions
199 void insert( UnionInstType *inst, const std::list< TypeExpr* > &typeSubs, UnionDecl *decl ) { instantiations.insert( inst->get_baseUnion(), typeSubs, decl ); }
200
201 void replaceParametersWithConcrete( std::list< Expression* >& params );
202 Type *replaceWithConcrete( Type *type, bool doClone );
203
204 /// Strips a dtype-static aggregate decl of its type parameters, marks it as stripped
205 void stripDtypeParams( AggregateDecl *base, std::list< TypeDecl* >& baseParams, const std::list< TypeExpr* >& typeSubs );
206 };
207
208 void instantiateGeneric( std::list< Declaration* > &translationUnit ) {
209 EnvFinder finder;
210 mutateAll( translationUnit, finder );
211 GenericInstantiator instantiator( finder.envMap );
212 instantiator.mutateDeclarationList( translationUnit );
213 }
214
215 /// Makes substitutions of params into baseParams; returns dtypeStatic if there is a concrete instantiation based only on {d,f}type-to-void conversions,
216 /// concrete if there is a concrete instantiation requiring at least one parameter type, and dynamic if there is no concrete instantiation
217 genericType makeSubstitutions( const std::list< TypeDecl* >& baseParams, const std::list< Expression* >& params, std::list< TypeExpr* >& out ) {
218 genericType gt = genericType::dtypeStatic;
219
220 // substitute concrete types for given parameters, and incomplete types for placeholders
221 std::list< TypeDecl* >::const_iterator baseParam = baseParams.begin();
222 std::list< Expression* >::const_iterator param = params.begin();
223 for ( ; baseParam != baseParams.end() && param != params.end(); ++baseParam, ++param ) {
224 TypeExpr *paramType = dynamic_cast< TypeExpr* >( *param );
225 assert(paramType && "Aggregate parameters should be type expressions");
226
227 if ( (*baseParam)->isComplete() ) {
228 // substitute parameter for complete (otype or sized dtype) type; makes the struct concrete or dynamic depending on the parameter
229 out.push_back( paramType->clone() );
230 gt |= isPolyType( paramType->get_type() ) ? genericType::dynamic : genericType::concrete;
231 } else switch ( (*baseParam)->get_kind() ) {
232 case TypeDecl::Dtype:
233 // can pretend that any incomplete dtype is `void`
234 out.push_back( new TypeExpr( new VoidType( Type::Qualifiers() ) ) );
235 break;
236 case TypeDecl::Ftype:
237 // can pretend that any ftype is `void (*)(void)`
238 out.push_back( new TypeExpr( new FunctionType( Type::Qualifiers(), false ) ) );
239 break;
240 case TypeDecl::Ttype:
241 assertf( false, "Ttype parameters are not currently allowed as parameters to generic types." );
242 break;
243 case TypeDecl::Any:
244 assertf( false, "otype parameters handled by baseParam->isComplete()." );
245 break;
246 }
247 }
248
249 assert( baseParam == baseParams.end() && param == params.end() && "Type parameters should match type variables" );
250 return gt;
251 }
252
253 /// Substitutes types of members of in according to baseParams => typeSubs, appending the result to out
254 void substituteMembers( const std::list< Declaration* >& in, const std::list< TypeDecl* >& baseParams, const std::list< TypeExpr* >& typeSubs,
255 std::list< Declaration* >& out ) {
256 // substitute types into new members
257 TypeSubstitution subs( baseParams.begin(), baseParams.end(), typeSubs.begin() );
258 for ( std::list< Declaration* >::const_iterator member = in.begin(); member != in.end(); ++member ) {
259 Declaration *newMember = (*member)->clone();
260 subs.apply(newMember);
261 out.push_back( newMember );
262 }
263 }
264
265 /// Substitutes types of members according to baseParams => typeSubs, working in-place
266 void substituteMembers( std::list< Declaration* >& members, const std::list< TypeDecl* >& baseParams, const std::list< TypeExpr* >& typeSubs ) {
267 // substitute types into new members
268 TypeSubstitution subs( baseParams.begin(), baseParams.end(), typeSubs.begin() );
269 for ( std::list< Declaration* >::iterator member = members.begin(); member != members.end(); ++member ) {
270 subs.apply(*member);
271 }
272 }
273
274 /// Strips the instances's type parameters
275 void stripInstParams( ReferenceToType *inst ) {
276 deleteAll( inst->get_parameters() );
277 inst->get_parameters().clear();
278 }
279
280 void GenericInstantiator::stripDtypeParams( AggregateDecl *base, std::list< TypeDecl* >& baseParams, const std::list< TypeExpr* >& typeSubs ) {
281 substituteMembers( base->get_members(), baseParams, typeSubs );
282
283 deleteAll( baseParams );
284 baseParams.clear();
285
286 dtypeStatics.insert( base );
287 }
288
289 /// xxx - more or less copied from box -- these should be merged with those somehow...
290 void GenericInstantiator::replaceParametersWithConcrete( std::list< Expression* >& params ) {
291 for ( std::list< Expression* >::iterator param = params.begin(); param != params.end(); ++param ) {
292 TypeExpr *paramType = dynamic_cast< TypeExpr* >( *param );
293 assertf(paramType, "Aggregate parameters should be type expressions");
294 paramType->set_type( replaceWithConcrete( paramType->get_type(), false ) );
295 }
296 }
297
298 Type *GenericInstantiator::replaceWithConcrete( Type *type, bool doClone ) {
299 if ( TypeInstType *typeInst = dynamic_cast< TypeInstType * >( type ) ) {
300 if ( envMap.count( typeInst ) ) {
301 TypeSubstitution * env = envMap.at( typeInst );
302 Type *concrete = env->lookup( typeInst->get_name() );
303 if ( concrete ) {
304 return concrete->clone();
305 }
306 else return typeInst->clone();
307 }
308 } else if ( StructInstType *structType = dynamic_cast< StructInstType* >( type ) ) {
309 if ( doClone ) {
310 structType = structType->clone();
311 }
312 replaceParametersWithConcrete( structType->get_parameters() );
313 return structType;
314 } else if ( UnionInstType *unionType = dynamic_cast< UnionInstType* >( type ) ) {
315 if ( doClone ) {
316 unionType = unionType->clone();
317 }
318 replaceParametersWithConcrete( unionType->get_parameters() );
319 return unionType;
320 }
321 return type;
322 }
323
324
325 Type* GenericInstantiator::mutate( StructInstType *inst ) {
326 // mutate subtypes
327 Type *mutated = Mutator::mutate( inst );
328 inst = dynamic_cast< StructInstType* >( mutated );
329 if ( ! inst ) return mutated;
330
331 // exit early if no need for further mutation
332 if ( inst->get_parameters().empty() ) return inst;
333
334 // need to replace type variables to ensure that generic types are instantiated for the return values of polymorphic functions (in particular, for thunks, because they are not [currently] copy constructed).
335 replaceWithConcrete( inst, false );
336
337 // check for an already-instantiatiated dtype-static type
338 if ( dtypeStatics.find( inst->get_baseStruct() ) != dtypeStatics.end() ) {
339 stripInstParams( inst );
340 return inst;
341 }
342
343 // check if type can be concretely instantiated; put substitutions into typeSubs
344 assertf( inst->get_baseParameters(), "Base struct has parameters" );
345 std::list< TypeExpr* > typeSubs;
346 genericType gt = makeSubstitutions( *inst->get_baseParameters(), inst->get_parameters(), typeSubs );
347 switch ( gt ) {
348 case genericType::dtypeStatic:
349 stripDtypeParams( inst->get_baseStruct(), *inst->get_baseParameters(), typeSubs );
350 stripInstParams( inst );
351 break;
352
353 case genericType::concrete: {
354 // make concrete instantiation of generic type
355 StructDecl *concDecl = lookup( inst, typeSubs );
356 if ( ! concDecl ) {
357 // set concDecl to new type, insert type declaration into statements to add
358 concDecl = new StructDecl( typeNamer.newName( inst->get_name() ) );
359 concDecl->set_body( inst->get_baseStruct()->has_body() );
360 substituteMembers( inst->get_baseStruct()->get_members(), *inst->get_baseParameters(), typeSubs, concDecl->get_members() );
361 DeclMutator::addDeclaration( concDecl );
362 insert( inst, typeSubs, concDecl );
363 }
364 StructInstType *newInst = new StructInstType( inst->get_qualifiers(), concDecl->get_name() );
365 newInst->set_baseStruct( concDecl );
366
367 delete inst;
368 inst = newInst;
369 break;
370 }
371
372 case genericType::dynamic:
373 // do nothing
374 break;
375 }
376
377 deleteAll( typeSubs );
378 return inst;
379 }
380
381 Type* GenericInstantiator::mutate( UnionInstType *inst ) {
382 // mutate subtypes
383 Type *mutated = Mutator::mutate( inst );
384 inst = dynamic_cast< UnionInstType* >( mutated );
385 if ( ! inst ) return mutated;
386
387 // exit early if no need for further mutation
388 if ( inst->get_parameters().empty() ) return inst;
389
390 // check for an already-instantiatiated dtype-static type
391 if ( dtypeStatics.find( inst->get_baseUnion() ) != dtypeStatics.end() ) {
392 stripInstParams( inst );
393 return inst;
394 }
395
396 // check if type can be concretely instantiated; put substitutions into typeSubs
397 assert( inst->get_baseParameters() && "Base union has parameters" );
398 std::list< TypeExpr* > typeSubs;
399 genericType gt = makeSubstitutions( *inst->get_baseParameters(), inst->get_parameters(), typeSubs );
400 switch ( gt ) {
401 case genericType::dtypeStatic:
402 stripDtypeParams( inst->get_baseUnion(), *inst->get_baseParameters(), typeSubs );
403 stripInstParams( inst );
404 break;
405
406 case genericType::concrete:
407 {
408 // make concrete instantiation of generic type
409 UnionDecl *concDecl = lookup( inst, typeSubs );
410 if ( ! concDecl ) {
411 // set concDecl to new type, insert type declaration into statements to add
412 concDecl = new UnionDecl( typeNamer.newName( inst->get_name() ) );
413 concDecl->set_body( inst->get_baseUnion()->has_body() );
414 substituteMembers( inst->get_baseUnion()->get_members(), *inst->get_baseParameters(), typeSubs, concDecl->get_members() );
415 DeclMutator::addDeclaration( concDecl );
416 insert( inst, typeSubs, concDecl );
417 }
418 UnionInstType *newInst = new UnionInstType( inst->get_qualifiers(), concDecl->get_name() );
419 newInst->set_baseUnion( concDecl );
420
421 delete inst;
422 inst = newInst;
423 break;
424 }
425 case genericType::dynamic:
426 // do nothing
427 break;
428 }
429
430 deleteAll( typeSubs );
431 return inst;
432 }
433
434 void GenericInstantiator::doBeginScope() {
435 DeclMutator::doBeginScope();
436 instantiations.beginScope();
437 dtypeStatics.beginScope();
438 }
439
440 void GenericInstantiator::doEndScope() {
441 DeclMutator::doEndScope();
442 instantiations.endScope();
443 dtypeStatics.endScope();
444 }
445
446} // namespace GenPoly
447
448// Local Variables: //
449// tab-width: 4 //
450// mode: c++ //
451// compile-command: "make install" //
452// End: //
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