source: src/GenPoly/InstantiateGeneric.cc@ 96fc67b

ADT arm-eh ast-experimental cleanup-dtors enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 96fc67b was 760ba67, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

Temporarily remove type parameter delete for dtype-static generics [fixes #55]
  • Property mode set to 100644
File size: 19.7 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#include "InstantiateGeneric.h"
16
17#include <cassert> // for assertf, assert
18#include <iterator> // for back_inserter, inserter
19#include <list> // for list, _List_const_iterator
20#include <utility> // for move, pair
21#include <vector> // for vector
22
23#include "Common/PassVisitor.h" // for PassVisitor, WithDeclsToAdd
24#include "Common/ScopedMap.h" // for ScopedMap
25#include "Common/SemanticError.h" // for SemanticError
26#include "Common/UniqueName.h" // for UniqueName
27#include "Common/utility.h" // for deleteAll, cloneAll
28#include "GenPoly.h" // for isPolyType, typesPolyCompatible
29#include "ScopedSet.h" // for ScopedSet, ScopedSet<>::iterator
30#include "ScrubTyVars.h" // for ScrubTyVars
31#include "SynTree/Declaration.h" // for StructDecl, UnionDecl, TypeDecl
32#include "SynTree/Expression.h" // for TypeExpr, Expression
33#include "SynTree/Mutator.h" // for mutateAll
34#include "SynTree/Type.h" // for StructInstType, UnionInstType
35#include "SynTree/TypeSubstitution.h" // for TypeSubstitution
36#include "SynTree/Visitor.h" // for acceptAll
37
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 for ( std::list< Type* >::const_iterator it = params.begin(), jt = that.params.begin(); it != params.end(); ++it, ++jt ) {
80 if ( ! typesPolyCompatible( *it, *jt ) ) return false;
81 }
82 return true;
83 }
84
85 std::list< Type* > params; ///< Instantiation parameters
86 };
87
88 /// Maps a key and a TypeList to the some value, accounting for scope
89 template< typename Key, typename Value >
90 class InstantiationMap {
91 /// Wraps value for a specific (Key, TypeList) combination
92 typedef std::pair< TypeList, Value* > Instantiation;
93 /// List of TypeLists paired with their appropriate values
94 typedef std::vector< Instantiation > ValueList;
95 /// Underlying map type; maps keys to a linear list of corresponding TypeLists and values
96 typedef ScopedMap< Key*, ValueList > InnerMap;
97
98 InnerMap instantiations; ///< instantiations
99
100 public:
101 /// Starts a new scope
102 void beginScope() { instantiations.beginScope(); }
103
104 /// Ends a scope
105 void endScope() { instantiations.endScope(); }
106
107 /// Gets the value for the (key, typeList) pair, returns NULL on none such.
108 Value *lookup( Key *key, const std::list< TypeExpr* >& params ) const {
109 TypeList typeList( params );
110
111 // scan scopes for matches to the key
112 for ( typename InnerMap::const_iterator insts = instantiations.find( key ); insts != instantiations.end(); insts = instantiations.findNext( insts, key ) ) {
113 for ( typename ValueList::const_reverse_iterator inst = insts->second.rbegin(); inst != insts->second.rend(); ++inst ) {
114 if ( inst->first == typeList ) return inst->second;
115 }
116 }
117 // no matching instantiations found
118 return 0;
119 }
120
121 /// Adds a value for a (key, typeList) pair to the current scope
122 void insert( Key *key, const std::list< TypeExpr* > &params, Value *value ) {
123 auto it = instantiations.findAt( instantiations.currentScope(), key );
124 if ( it == instantiations.end() ) {
125 instantiations.insert( key, ValueList{ Instantiation{ TypeList( params ), value } } );
126 } else {
127 it->second.push_back( Instantiation{ TypeList( params ), value } );
128 }
129 }
130 };
131
132 /// Possible options for a given specialization of a generic type
133 enum class genericType {
134 dtypeStatic, ///< Concrete instantiation based solely on {d,f}type-to-void conversions
135 concrete, ///< Concrete instantiation requiring at least one parameter type
136 dynamic ///< No concrete instantiation
137 };
138
139 genericType& operator |= ( genericType& gt, const genericType& ht ) {
140 switch ( gt ) {
141 case genericType::dtypeStatic:
142 gt = ht;
143 break;
144 case genericType::concrete:
145 if ( ht == genericType::dynamic ) { gt = genericType::dynamic; }
146 break;
147 case genericType::dynamic:
148 // nothing possible
149 break;
150 }
151 return gt;
152 }
153
154 /// Mutator pass that replaces concrete instantiations of generic types with actual struct declarations, scoped appropriately
155 struct GenericInstantiator final : public WithTypeSubstitution, public WithDeclsToAdd, public WithVisitorRef<GenericInstantiator>, public WithGuards {
156 /// Map of (generic type, parameter list) pairs to concrete type instantiations
157 InstantiationMap< AggregateDecl, AggregateDecl > instantiations;
158 /// Set of types which are dtype-only generic (and therefore have static layout)
159 ScopedSet< AggregateDecl* > dtypeStatics;
160 /// Namer for concrete types
161 UniqueName typeNamer;
162 /// Should not make use of type environment to replace types of function parameter and return values.
163 bool inFunctionType = false;
164 /// Index of current member, used to recreate MemberExprs with the member from an instantiation
165 int memberIndex = -1;
166 GenericInstantiator() : instantiations(), dtypeStatics(), typeNamer("_conc_") {}
167
168 Type* postmutate( StructInstType *inst );
169 Type* postmutate( UnionInstType *inst );
170
171 // fix MemberExprs to use the member from the instantiation
172 void premutate( MemberExpr * memberExpr );
173 Expression * postmutate( MemberExpr * memberExpr );
174
175 void premutate( FunctionType * ) {
176 GuardValue( inFunctionType );
177 inFunctionType = true;
178 }
179
180 void beginScope();
181 void endScope();
182 private:
183 /// Wrap instantiation lookup for structs
184 StructDecl* lookup( StructInstType *inst, const std::list< TypeExpr* > &typeSubs ) { return (StructDecl*)instantiations.lookup( inst->get_baseStruct(), typeSubs ); }
185 /// Wrap instantiation lookup for unions
186 UnionDecl* lookup( UnionInstType *inst, const std::list< TypeExpr* > &typeSubs ) { return (UnionDecl*)instantiations.lookup( inst->get_baseUnion(), typeSubs ); }
187 /// Wrap instantiation insertion for structs
188 void insert( StructInstType *inst, const std::list< TypeExpr* > &typeSubs, StructDecl *decl ) { instantiations.insert( inst->get_baseStruct(), typeSubs, decl ); }
189 /// Wrap instantiation insertion for unions
190 void insert( UnionInstType *inst, const std::list< TypeExpr* > &typeSubs, UnionDecl *decl ) { instantiations.insert( inst->get_baseUnion(), typeSubs, decl ); }
191
192 void replaceParametersWithConcrete( std::list< Expression* >& params );
193 Type *replaceWithConcrete( Type *type, bool doClone );
194
195 /// Strips a dtype-static aggregate decl of its type parameters, marks it as stripped
196 void stripDtypeParams( AggregateDecl *base, std::list< TypeDecl* >& baseParams, const std::list< TypeExpr* >& typeSubs );
197 };
198
199 void instantiateGeneric( std::list< Declaration* > &translationUnit ) {
200 PassVisitor<GenericInstantiator> instantiator;
201 mutateAll( translationUnit, instantiator );
202 }
203
204 /// Makes substitutions of params into baseParams; returns dtypeStatic if there is a concrete instantiation based only on {d,f}type-to-void conversions,
205 /// concrete if there is a concrete instantiation requiring at least one parameter type, and dynamic if there is no concrete instantiation
206 genericType makeSubstitutions( const std::list< TypeDecl* >& baseParams, const std::list< Expression* >& params, std::list< TypeExpr* >& out ) {
207 genericType gt = genericType::dtypeStatic;
208
209 // substitute concrete types for given parameters, and incomplete types for placeholders
210 std::list< TypeDecl* >::const_iterator baseParam = baseParams.begin();
211 std::list< Expression* >::const_iterator param = params.begin();
212 for ( ; baseParam != baseParams.end() && param != params.end(); ++baseParam, ++param ) {
213 TypeExpr *paramType = dynamic_cast< TypeExpr* >( *param );
214 assert(paramType && "Aggregate parameters should be type expressions");
215
216 if ( (*baseParam)->isComplete() ) {
217 // substitute parameter for complete (otype or sized dtype) type
218 if ( isPolyType( paramType->get_type() ) ) {
219 // substitute polymorphic parameter type in to generic type
220 out.push_back( paramType->clone() );
221 gt = genericType::dynamic;
222 } else {
223 // normalize possibly dtype-static parameter type
224 out.push_back( new TypeExpr{
225 ScrubTyVars::scrubAll( paramType->get_type()->clone() ) } );
226 gt |= genericType::concrete;
227 }
228 } else switch ( (*baseParam)->get_kind() ) {
229 case TypeDecl::Dtype:
230 // can pretend that any incomplete dtype is `void`
231 out.push_back( new TypeExpr( new VoidType( Type::Qualifiers() ) ) );
232 break;
233 case TypeDecl::Ftype:
234 // can pretend that any ftype is `void (*)(void)`
235 out.push_back( new TypeExpr( new FunctionType( Type::Qualifiers(), false ) ) );
236 break;
237 case TypeDecl::Ttype:
238 assertf( false, "Ttype parameters are not currently allowed as parameters to generic types." );
239 break;
240 default:
241 assertf( false, "Unhandled type parameter kind" );
242 break;
243 }
244 }
245
246 assertf( baseParam == baseParams.end() && param == params.end(), "Type parameters should match type variables" );
247 return gt;
248 }
249
250 /// Substitutes types of members of in according to baseParams => typeSubs, appending the result to out
251 void substituteMembers( const std::list< Declaration* >& in, const std::list< TypeDecl* >& baseParams, const std::list< TypeExpr* >& typeSubs,
252 std::list< Declaration* >& out ) {
253 // substitute types into new members
254 TypeSubstitution subs( baseParams.begin(), baseParams.end(), typeSubs.begin() );
255 for ( std::list< Declaration* >::const_iterator member = in.begin(); member != in.end(); ++member ) {
256 Declaration *newMember = (*member)->clone();
257 subs.apply(newMember);
258 out.push_back( newMember );
259 }
260 }
261
262 /// Substitutes types of members according to baseParams => typeSubs, working in-place
263 void substituteMembers( std::list< Declaration* >& members, const std::list< TypeDecl* >& baseParams, const std::list< TypeExpr* >& typeSubs ) {
264 // substitute types into new members
265 TypeSubstitution subs( baseParams.begin(), baseParams.end(), typeSubs.begin() );
266 for ( std::list< Declaration* >::iterator member = members.begin(); member != members.end(); ++member ) {
267 subs.apply(*member);
268 }
269 }
270
271 /// Strips the instances's type parameters
272 void stripInstParams( ReferenceToType *inst ) {
273 deleteAll( inst->get_parameters() );
274 inst->get_parameters().clear();
275 }
276
277 void GenericInstantiator::stripDtypeParams( AggregateDecl *base, std::list< TypeDecl* >& baseParams, const std::list< TypeExpr* >& typeSubs ) {
278 substituteMembers( base->get_members(), baseParams, typeSubs );
279
280 // xxx - can't delete type parameters because they may have assertions that are used
281 // deleteAll( baseParams );
282 baseParams.clear();
283
284 dtypeStatics.insert( base );
285 }
286
287 /// xxx - more or less copied from box -- these should be merged with those somehow...
288 void GenericInstantiator::replaceParametersWithConcrete( std::list< Expression* >& params ) {
289 for ( std::list< Expression* >::iterator param = params.begin(); param != params.end(); ++param ) {
290 TypeExpr *paramType = dynamic_cast< TypeExpr* >( *param );
291 assertf(paramType, "Aggregate parameters should be type expressions");
292 paramType->set_type( replaceWithConcrete( paramType->get_type(), false ) );
293 }
294 }
295
296 Type *GenericInstantiator::replaceWithConcrete( Type *type, bool doClone ) {
297 if ( TypeInstType *typeInst = dynamic_cast< TypeInstType * >( type ) ) {
298 if ( env && ! inFunctionType ) {
299 Type *concrete = env->lookup( typeInst->get_name() );
300 if ( concrete ) {
301 return concrete->clone();
302 }
303 else return typeInst->clone();
304 }
305 } else if ( StructInstType *structType = dynamic_cast< StructInstType* >( type ) ) {
306 if ( doClone ) {
307 structType = structType->clone();
308 }
309 replaceParametersWithConcrete( structType->get_parameters() );
310 return structType;
311 } else if ( UnionInstType *unionType = dynamic_cast< UnionInstType* >( type ) ) {
312 if ( doClone ) {
313 unionType = unionType->clone();
314 }
315 replaceParametersWithConcrete( unionType->get_parameters() );
316 return unionType;
317 }
318 return type;
319 }
320
321
322 Type* GenericInstantiator::postmutate( StructInstType *inst ) {
323 // exit early if no need for further mutation
324 if ( inst->get_parameters().empty() ) return inst;
325
326 // 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).
327 replaceWithConcrete( inst, false );
328
329 // check for an already-instantiatiated dtype-static type
330 if ( dtypeStatics.find( inst->get_baseStruct() ) != dtypeStatics.end() ) {
331 stripInstParams( inst );
332 return inst;
333 }
334
335 // check if type can be concretely instantiated; put substitutions into typeSubs
336 assertf( inst->get_baseParameters(), "Base struct has parameters" );
337 std::list< TypeExpr* > typeSubs;
338 genericType gt = makeSubstitutions( *inst->get_baseParameters(), inst->get_parameters(), typeSubs );
339 switch ( gt ) {
340 case genericType::dtypeStatic:
341 stripDtypeParams( inst->get_baseStruct(), *inst->get_baseParameters(), typeSubs );
342 stripInstParams( inst );
343 break;
344
345 case genericType::concrete: {
346 // make concrete instantiation of generic type
347 StructDecl *concDecl = lookup( inst, typeSubs );
348 if ( ! concDecl ) {
349 // set concDecl to new type, insert type declaration into statements to add
350 concDecl = new StructDecl( typeNamer.newName( inst->get_name() ) );
351 concDecl->set_body( inst->get_baseStruct()->has_body() );
352 substituteMembers( inst->get_baseStruct()->get_members(), *inst->get_baseParameters(), typeSubs, concDecl->get_members() );
353 insert( inst, typeSubs, concDecl ); // must insert before recursion
354 concDecl->acceptMutator( *visitor ); // recursively instantiate members
355 declsToAddBefore.push_back( concDecl ); // must occur before declaration is added so that member instantiations appear first
356 }
357 StructInstType *newInst = new StructInstType( inst->get_qualifiers(), concDecl->get_name() );
358 newInst->set_baseStruct( concDecl );
359
360 delete inst;
361 inst = newInst;
362 break;
363 }
364
365 case genericType::dynamic:
366 // do nothing
367 break;
368 }
369
370 deleteAll( typeSubs );
371 return inst;
372 }
373
374 Type* GenericInstantiator::postmutate( UnionInstType *inst ) {
375 // exit early if no need for further mutation
376 if ( inst->get_parameters().empty() ) return inst;
377
378 // check for an already-instantiatiated dtype-static type
379 if ( dtypeStatics.find( inst->get_baseUnion() ) != dtypeStatics.end() ) {
380 stripInstParams( inst );
381 return inst;
382 }
383
384 // check if type can be concretely instantiated; put substitutions into typeSubs
385 assert( inst->get_baseParameters() && "Base union has parameters" );
386 std::list< TypeExpr* > typeSubs;
387 genericType gt = makeSubstitutions( *inst->get_baseParameters(), inst->get_parameters(), typeSubs );
388 switch ( gt ) {
389 case genericType::dtypeStatic:
390 stripDtypeParams( inst->get_baseUnion(), *inst->get_baseParameters(), typeSubs );
391 stripInstParams( inst );
392 break;
393
394 case genericType::concrete:
395 {
396 // make concrete instantiation of generic type
397 UnionDecl *concDecl = lookup( inst, typeSubs );
398 if ( ! concDecl ) {
399 // set concDecl to new type, insert type declaration into statements to add
400 concDecl = new UnionDecl( typeNamer.newName( inst->get_name() ) );
401 concDecl->set_body( inst->get_baseUnion()->has_body() );
402 substituteMembers( inst->get_baseUnion()->get_members(), *inst->get_baseParameters(), typeSubs, concDecl->get_members() );
403 insert( inst, typeSubs, concDecl ); // must insert before recursion
404 concDecl->acceptMutator( *visitor ); // recursively instantiate members
405 declsToAddBefore.push_back( concDecl ); // must occur before declaration is added so that member instantiations appear first
406 }
407 UnionInstType *newInst = new UnionInstType( inst->get_qualifiers(), concDecl->get_name() );
408 newInst->set_baseUnion( concDecl );
409
410 delete inst;
411 inst = newInst;
412 break;
413 }
414 case genericType::dynamic:
415 // do nothing
416 break;
417 }
418
419 deleteAll( typeSubs );
420 return inst;
421 }
422
423 namespace {
424 bool isGenericType( Type * t ) {
425 if ( StructInstType * inst = dynamic_cast< StructInstType * >( t ) ) {
426 return ! inst->parameters.empty();
427 } else if ( UnionInstType * inst = dynamic_cast< UnionInstType * >( t ) ) {
428 return ! inst->parameters.empty();
429 }
430 return false;
431 }
432
433 AggregateDecl * getAggr( Type * t ) {
434 if ( StructInstType * inst = dynamic_cast< StructInstType * >( t ) ) {
435 return inst->baseStruct;
436 } else if ( UnionInstType * inst = dynamic_cast< UnionInstType * >( t ) ) {
437 return inst->baseUnion;
438 }
439 assertf( false, "Non-aggregate type: %s", toString( t ).c_str() );
440 }
441 }
442
443 void GenericInstantiator::premutate( MemberExpr * memberExpr ) {
444 GuardValue( memberIndex );
445 memberIndex = -1;
446 if ( isGenericType( memberExpr->aggregate->result ) ) {
447 // find the location of the member
448 AggregateDecl * aggr = getAggr( memberExpr->aggregate->result );
449 std::list< Declaration * > & members = aggr->members;
450 memberIndex = std::distance( members.begin(), std::find( members.begin(), members.end(), memberExpr->member ) );
451 assertf( memberIndex < (int)members.size(), "Could not find member %s in generic type %s", toString( memberExpr->member ).c_str(), toString( memberExpr->aggregate ).c_str() );
452 }
453 }
454
455 Expression * GenericInstantiator::postmutate( MemberExpr * memberExpr ) {
456 if ( memberIndex != -1 ) {
457 // using the location from the generic type, find the member in the instantiation and rebuild the member expression
458 AggregateDecl * aggr = getAggr( memberExpr->aggregate->result );
459 assertf( memberIndex < (int)aggr->members.size(), "Instantiation somehow has fewer members than the generic type." );
460 Declaration * member = *std::next( aggr->members.begin(), memberIndex );
461 assertf( member->name == memberExpr->member->name, "Instantiation has different member order than the generic type. %s / %s", toString( member ).c_str(), toString( memberExpr->member ).c_str() );
462 DeclarationWithType * field = strict_dynamic_cast< DeclarationWithType * >( member );
463 MemberExpr * ret = new MemberExpr( field, memberExpr->aggregate->clone() );
464 std::swap( ret->env, memberExpr->env );
465 delete memberExpr;
466 return ret;
467 }
468 return memberExpr;
469 }
470
471 void GenericInstantiator::beginScope() {
472 instantiations.beginScope();
473 dtypeStatics.beginScope();
474 }
475
476 void GenericInstantiator::endScope() {
477 instantiations.endScope();
478 dtypeStatics.endScope();
479 }
480
481} // namespace GenPoly
482
483// Local Variables: //
484// tab-width: 4 //
485// mode: c++ //
486// compile-command: "make install" //
487// End: //
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