source: src/Tuples/TupleExpansion.cc@ 946bcca

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 946bcca was 64ac636, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

fix missing line numbers in some places, including member constructor generation
  • Property mode set to 100644
File size: 14.4 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// TupleAssignment.cc --
8//
9// Author : Rodolfo G. Esteves
10// Created On : Mon May 18 07:44:20 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Thu Mar 16 08:05:17 2017
13// Update Count : 15
14//
15
16#include <iterator>
17#include <iostream>
18#include <cassert>
19#include "Tuples.h"
20#include "GenPoly/DeclMutator.h"
21#include "SynTree/Mutator.h"
22#include "SynTree/Statement.h"
23#include "SynTree/Declaration.h"
24#include "SynTree/Type.h"
25#include "SynTree/Expression.h"
26#include "SynTree/Initializer.h"
27#include "SymTab/Mangler.h"
28#include "Common/ScopedMap.h"
29#include "ResolvExpr/typeops.h"
30#include "InitTweak/GenInit.h"
31#include "InitTweak/InitTweak.h"
32
33namespace Tuples {
34 namespace {
35 class MemberTupleExpander final : public Mutator {
36 public:
37 typedef Mutator Parent;
38 using Parent::mutate;
39
40 virtual Expression * mutate( UntypedMemberExpr * memberExpr ) override;
41 };
42
43 class UniqueExprExpander final : public GenPoly::DeclMutator {
44 public:
45 typedef GenPoly::DeclMutator Parent;
46 using Parent::mutate;
47
48 virtual Expression * mutate( UniqueExpr * unqExpr ) override;
49
50 std::map< int, Expression * > decls; // not vector, because order added may not be increasing order
51
52 ~UniqueExprExpander() {
53 for ( std::pair<const int, Expression *> & p : decls ) {
54 delete p.second;
55 }
56 }
57 };
58
59 class TupleAssignExpander : public Mutator {
60 public:
61 typedef Mutator Parent;
62 using Parent::mutate;
63
64 virtual Expression * mutate( TupleAssignExpr * tupleExpr );
65 };
66
67 class TupleTypeReplacer : public GenPoly::DeclMutator {
68 public:
69 typedef GenPoly::DeclMutator Parent;
70 using Parent::mutate;
71
72 virtual Type * mutate( TupleType * tupleType ) override;
73
74 virtual CompoundStmt * mutate( CompoundStmt * stmt ) override {
75 typeMap.beginScope();
76 stmt = Parent::mutate( stmt );
77 typeMap.endScope();
78 return stmt;
79 }
80 private:
81 ScopedMap< int, StructDecl * > typeMap;
82 };
83
84 class TupleIndexExpander final : public Mutator {
85 public:
86 typedef Mutator Parent;
87 using Parent::mutate;
88
89 virtual Expression * mutate( TupleIndexExpr * tupleExpr ) override;
90 };
91
92 class TupleExprExpander final : public Mutator {
93 public:
94 typedef Mutator Parent;
95 using Parent::mutate;
96
97 virtual Expression * mutate( TupleExpr * tupleExpr ) override;
98 };
99 }
100
101 void expandMemberTuples( std::list< Declaration * > & translationUnit ) {
102 MemberTupleExpander expander;
103 mutateAll( translationUnit, expander );
104 }
105
106 void expandUniqueExpr( std::list< Declaration * > & translationUnit ) {
107 UniqueExprExpander unqExpander;
108 unqExpander.mutateDeclarationList( translationUnit );
109 }
110
111 void expandTuples( std::list< Declaration * > & translationUnit ) {
112 TupleAssignExpander assnExpander;
113 mutateAll( translationUnit, assnExpander );
114
115 TupleTypeReplacer replacer;
116 replacer.mutateDeclarationList( translationUnit );
117
118 TupleIndexExpander idxExpander;
119 mutateAll( translationUnit, idxExpander );
120
121 TupleExprExpander exprExpander;
122 mutateAll( translationUnit, exprExpander );
123 }
124
125 namespace {
126 /// given a expression representing the member and an expression representing the aggregate,
127 /// reconstructs a flattened UntypedMemberExpr with the right precedence
128 Expression * reconstructMemberExpr( Expression * member, Expression * aggr, CodeLocation & loc ) {
129 if ( UntypedMemberExpr * memberExpr = dynamic_cast< UntypedMemberExpr * >( member ) ) {
130 // construct a new UntypedMemberExpr with the correct structure , and recursively
131 // expand that member expression.
132 MemberTupleExpander expander;
133 UntypedMemberExpr * inner = new UntypedMemberExpr( memberExpr->get_aggregate(), aggr->clone() );
134 UntypedMemberExpr * newMemberExpr = new UntypedMemberExpr( memberExpr->get_member(), inner );
135 inner->location = newMemberExpr->location = loc;
136 memberExpr->set_member(nullptr);
137 memberExpr->set_aggregate(nullptr);
138 delete memberExpr;
139 return newMemberExpr->acceptMutator( expander );
140 } else {
141 // not a member expression, so there is nothing to do but attach and return
142 UntypedMemberExpr * newMemberExpr = new UntypedMemberExpr( member, aggr->clone() );
143 newMemberExpr->location = loc;
144 return newMemberExpr;
145 }
146 }
147 }
148
149 Expression * MemberTupleExpander::mutate( UntypedMemberExpr * memberExpr ) {
150 if ( UntypedTupleExpr * tupleExpr = dynamic_cast< UntypedTupleExpr * > ( memberExpr->get_member() ) ) {
151 Expression * aggr = memberExpr->get_aggregate()->clone()->acceptMutator( *this );
152 // aggregate expressions which might be impure must be wrapped in unique expressions
153 // xxx - if there's a member-tuple expression nested in the aggregate, this currently generates the wrong code if a UniqueExpr is not used, and it's purely an optimization to remove the UniqueExpr
154 // if ( Tuples::maybeImpure( memberExpr->get_aggregate() ) ) aggr = new UniqueExpr( aggr );
155 aggr = new UniqueExpr( aggr );
156 for ( Expression *& expr : tupleExpr->get_exprs() ) {
157 expr = reconstructMemberExpr( expr, aggr, memberExpr->location );
158 expr->location = memberExpr->location;
159 }
160 delete aggr;
161 tupleExpr->location = memberExpr->location;
162 return tupleExpr;
163 } else {
164 // there may be a tuple expr buried in the aggregate
165 // xxx - this is a memory leak
166 UntypedMemberExpr * newMemberExpr = new UntypedMemberExpr( memberExpr->get_member()->clone(), memberExpr->get_aggregate()->acceptMutator( *this ) );
167 newMemberExpr->location = memberExpr->location;
168 return newMemberExpr;
169 }
170 }
171
172 Expression * UniqueExprExpander::mutate( UniqueExpr * unqExpr ) {
173 unqExpr = safe_dynamic_cast< UniqueExpr * > ( Parent::mutate( unqExpr ) );
174 const int id = unqExpr->get_id();
175
176 // on first time visiting a unique expr with a particular ID, generate the expression that replaces all UniqueExprs with that ID,
177 // and lookup on subsequent hits. This ensures that all unique exprs with the same ID reference the same variable.
178 if ( ! decls.count( id ) ) {
179 Expression * assignUnq;
180 Expression * var = unqExpr->get_var();
181 if ( unqExpr->get_object() ) {
182 // an object was generated to represent this unique expression -- it should be added to the list of declarations now
183 addDeclaration( unqExpr->get_object() );
184 unqExpr->set_object( nullptr );
185 // steal the expr from the unqExpr
186 assignUnq = UntypedExpr::createAssign( unqExpr->get_var()->clone(), unqExpr->get_expr() );
187 unqExpr->set_expr( nullptr );
188 } else {
189 // steal the already generated assignment to var from the unqExpr - this has been generated by FixInit
190 Expression * expr = unqExpr->get_expr();
191 CommaExpr * commaExpr = safe_dynamic_cast< CommaExpr * >( expr );
192 assignUnq = commaExpr->get_arg1();
193 commaExpr->set_arg1( nullptr );
194 }
195 BasicType * boolType = new BasicType( Type::Qualifiers(), BasicType::Bool );
196 ObjectDecl * finished = new ObjectDecl( toString( "_unq_expr_finished_", id ), Type::StorageClasses(), LinkageSpec::Cforall, nullptr, new BasicType( Type::Qualifiers(), BasicType::Bool ), new SingleInit( new ConstantExpr( Constant( boolType->clone(), "0" ) ), noDesignators ) );
197 addDeclaration( finished );
198 // (finished ? _unq_expr_N : (_unq_expr_N = <unqExpr->get_expr()>, finished = 1, _unq_expr_N))
199 // This pattern ensures that each unique expression is evaluated once, regardless of evaluation order of the generated C code.
200 Expression * assignFinished = UntypedExpr::createAssign( new VariableExpr(finished), new ConstantExpr( Constant( boolType->clone(), "1" ) ) );
201 ConditionalExpr * condExpr = new ConditionalExpr( new VariableExpr( finished ), var->clone(),
202 new CommaExpr( new CommaExpr( assignUnq, assignFinished ), var->clone() ) );
203 condExpr->set_result( var->get_result()->clone() );
204 condExpr->set_env( maybeClone( unqExpr->get_env() ) );
205 decls[id] = condExpr;
206 }
207 delete unqExpr;
208 return decls[id]->clone();
209 }
210
211 Expression * TupleAssignExpander::mutate( TupleAssignExpr * assnExpr ) {
212 assnExpr = safe_dynamic_cast< TupleAssignExpr * >( Parent::mutate( assnExpr ) );
213 StmtExpr * ret = assnExpr->get_stmtExpr();
214 assnExpr->set_stmtExpr( nullptr );
215 // move env to StmtExpr
216 ret->set_env( assnExpr->get_env() );
217 assnExpr->set_env( nullptr );
218 delete assnExpr;
219 return ret;
220 }
221
222 Type * TupleTypeReplacer::mutate( TupleType * tupleType ) {
223 tupleType = safe_dynamic_cast< TupleType * > ( Parent::mutate( tupleType ) );
224 unsigned tupleSize = tupleType->size();
225 if ( ! typeMap.count( tupleSize ) ) {
226 // generate struct type to replace tuple type based on the number of components in the tuple
227 StructDecl * decl = new StructDecl( toString( "_tuple_type_", tupleSize ) );
228 decl->set_body( true );
229 for ( size_t i = 0; i < tupleSize; ++i ) {
230 TypeDecl * tyParam = new TypeDecl( toString( "tuple_param_", i ), Type::StorageClasses(), nullptr, TypeDecl::Any );
231 decl->get_members().push_back( new ObjectDecl( toString("field_", i ), Type::StorageClasses(), LinkageSpec::C, nullptr, new TypeInstType( Type::Qualifiers(), tyParam->get_name(), tyParam ), nullptr ) );
232 decl->get_parameters().push_back( tyParam );
233 }
234 if ( tupleSize == 0 ) {
235 // empty structs are not standard C. Add a dummy field to empty tuples to silence warnings when a compound literal Tuple0 is created.
236 decl->get_members().push_back( new ObjectDecl( "dummy", Type::StorageClasses(), LinkageSpec::C, nullptr, new BasicType( Type::Qualifiers(), BasicType::SignedInt ), nullptr ) );
237 }
238 typeMap[tupleSize] = decl;
239 addDeclaration( decl );
240 }
241 Type::Qualifiers qualifiers = tupleType->get_qualifiers();
242
243 StructDecl * decl = typeMap[tupleSize];
244 StructInstType * newType = new StructInstType( qualifiers, decl );
245 for ( Type * t : *tupleType ) {
246 newType->get_parameters().push_back( new TypeExpr( t->clone() ) );
247 }
248 delete tupleType;
249 return newType;
250 }
251
252 Expression * TupleIndexExpander::mutate( TupleIndexExpr * tupleExpr ) {
253 Expression * tuple = maybeMutate( tupleExpr->get_tuple(), *this );
254 assert( tuple );
255 tupleExpr->set_tuple( nullptr );
256 unsigned int idx = tupleExpr->get_index();
257 TypeSubstitution * env = tupleExpr->get_env();
258 tupleExpr->set_env( nullptr );
259 delete tupleExpr;
260
261 StructInstType * type = safe_dynamic_cast< StructInstType * >( tuple->get_result() );
262 StructDecl * structDecl = type->get_baseStruct();
263 assert( structDecl->get_members().size() > idx );
264 Declaration * member = *std::next(structDecl->get_members().begin(), idx);
265 MemberExpr * memExpr = new MemberExpr( safe_dynamic_cast< DeclarationWithType * >( member ), tuple );
266 memExpr->set_env( env );
267 return memExpr;
268 }
269
270 Expression * replaceTupleExpr( Type * result, const std::list< Expression * > & exprs, TypeSubstitution * env ) {
271 if ( result->isVoid() ) {
272 // void result - don't need to produce a value for cascading - just output a chain of comma exprs
273 assert( ! exprs.empty() );
274 std::list< Expression * >::const_iterator iter = exprs.begin();
275 Expression * expr = new CastExpr( *iter++ );
276 for ( ; iter != exprs.end(); ++iter ) {
277 expr = new CommaExpr( expr, new CastExpr( *iter ) );
278 }
279 expr->set_env( env );
280 return expr;
281 } else {
282 // typed tuple expression - produce a compound literal which performs each of the expressions
283 // as a distinct part of its initializer - the produced compound literal may be used as part of
284 // another expression
285 std::list< Initializer * > inits;
286 for ( Expression * expr : exprs ) {
287 inits.push_back( new SingleInit( expr ) );
288 }
289 Expression * expr = new CompoundLiteralExpr( result, new ListInit( inits ) );
290 expr->set_env( env );
291 return expr;
292 }
293 }
294
295 Expression * TupleExprExpander::mutate( TupleExpr * tupleExpr ) {
296 // recursively expand sub-tuple-expressions
297 tupleExpr = safe_dynamic_cast<TupleExpr *>(Parent::mutate(tupleExpr));
298 Type * result = tupleExpr->get_result();
299 std::list< Expression * > exprs = tupleExpr->get_exprs();
300 assert( result );
301 TypeSubstitution * env = tupleExpr->get_env();
302
303 // remove data from shell and delete it
304 tupleExpr->set_result( nullptr );
305 tupleExpr->get_exprs().clear();
306 tupleExpr->set_env( nullptr );
307 delete tupleExpr;
308
309 return replaceTupleExpr( result, exprs, env );
310 }
311
312 Type * makeTupleType( const std::list< Expression * > & exprs ) {
313 // produce the TupleType which aggregates the types of the exprs
314 TupleType *tupleType = new TupleType( Type::Qualifiers( Type::Const | Type::Volatile | Type::Restrict | Type::Lvalue | Type::Atomic | Type::Mutex ) );
315 Type::Qualifiers &qualifiers = tupleType->get_qualifiers();
316 for ( Expression * expr : exprs ) {
317 assert( expr->get_result() );
318 if ( expr->get_result()->isVoid() ) {
319 // if the type of any expr is void, the type of the entire tuple is void
320 delete tupleType;
321 return new VoidType( Type::Qualifiers() );
322 }
323 Type * type = expr->get_result()->clone();
324 tupleType->get_types().push_back( type );
325 // the qualifiers on the tuple type are the qualifiers that exist on all component types
326 qualifiers &= type->get_qualifiers();
327 } // for
328 if ( exprs.empty() ) qualifiers = Type::Qualifiers();
329 return tupleType;
330 }
331
332 TypeInstType * isTtype( Type * type ) {
333 if ( TypeInstType * inst = dynamic_cast< TypeInstType * >( type ) ) {
334 if ( inst->get_baseType()->get_kind() == TypeDecl::Ttype ) {
335 return inst;
336 }
337 }
338 return nullptr;
339 }
340
341 namespace {
342 /// determines if impurity (read: side-effects) may exist in a piece of code. Currently gives a very crude approximation, wherein any function call expression means the code may be impure
343 class ImpurityDetector : public Visitor {
344 public:
345 typedef Visitor Parent;
346 virtual void visit( ApplicationExpr * appExpr ) {
347 if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
348 if ( function->get_linkage() == LinkageSpec::Intrinsic ) {
349 if ( function->get_name() == "*?" || function->get_name() == "?[?]" ) {
350 // intrinsic dereference, subscript are pure, but need to recursively look for impurity
351 Parent::visit( appExpr );
352 return;
353 }
354 }
355 }
356 maybeImpure = true;
357 }
358 virtual void visit( UntypedExpr * untypedExpr ) { maybeImpure = true; }
359 bool maybeImpure = false;
360 };
361 } // namespace
362
363 bool maybeImpure( Expression * expr ) {
364 ImpurityDetector detector;
365 expr->accept( detector );
366 return detector.maybeImpure;
367 }
368} // namespace Tuples
369
370// Local Variables: //
371// tab-width: 4 //
372// mode: c++ //
373// compile-command: "make install" //
374// End: //
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