source: src/Tuples/TupleExpansion.cc@ b726084

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 b726084 was 141b786, checked in by Rob Schluntz <rschlunt@…>, 9 years ago

rework UniqueExpr, handle UniqueExpr in FixInit, fix translation for UniqueExprs, refactor explode functions and fix AddressExpr distribution over exploded tuple exprs
  • Property mode set to 100644
File size: 12.2 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 : Mon May 18 15:02:53 2015
13// Update Count : 2
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
32namespace Tuples {
33 namespace {
34 class MemberTupleExpander : public Mutator {
35 public:
36 typedef Mutator Parent;
37 virtual Expression * mutate( UntypedMemberExpr * memberExpr );
38 };
39
40 class UniqueExprExpander : public GenPoly::DeclMutator {
41 public:
42 typedef GenPoly::DeclMutator Parent;
43
44 virtual Expression * mutate( UniqueExpr * unqExpr );
45
46 std::map< int, Expression * > decls; // not vector, because order added may not be increasing order
47
48 ~UniqueExprExpander() {
49 for ( std::pair<const int, Expression *> & p : decls ) {
50 delete p.second;
51 }
52 }
53 };
54
55 class TupleAssignExpander : public Mutator {
56 public:
57 typedef Mutator Parent;
58 virtual Expression * mutate( TupleAssignExpr * tupleExpr );
59 };
60
61 class TupleTypeReplacer : public GenPoly::DeclMutator {
62 public:
63 typedef GenPoly::DeclMutator Parent;
64
65 virtual Type * mutate( TupleType * tupleType );
66
67 virtual CompoundStmt * mutate( CompoundStmt * stmt ) {
68 typeMap.beginScope();
69 stmt = Parent::mutate( stmt );
70 typeMap.endScope();
71 return stmt;
72 }
73 private:
74 ScopedMap< std::string, StructDecl * > typeMap;
75 };
76
77 class TupleIndexExpander : public Mutator {
78 public:
79 typedef Mutator Parent;
80 virtual Expression * mutate( TupleIndexExpr * tupleExpr );
81 };
82
83 class TupleExprExpander : public Mutator {
84 public:
85 typedef Mutator Parent;
86 virtual Expression * mutate( TupleExpr * tupleExpr );
87 };
88 }
89
90 void expandMemberTuples( std::list< Declaration * > & translationUnit ) {
91 MemberTupleExpander expander;
92 mutateAll( translationUnit, expander );
93 }
94
95 void expandUniqueExpr( std::list< Declaration * > & translationUnit ) {
96 UniqueExprExpander unqExpander;
97 unqExpander.mutateDeclarationList( translationUnit );
98 }
99
100 void expandTuples( std::list< Declaration * > & translationUnit ) {
101 TupleAssignExpander assnExpander;
102 mutateAll( translationUnit, assnExpander );
103
104 TupleTypeReplacer replacer;
105 replacer.mutateDeclarationList( translationUnit );
106
107 TupleIndexExpander idxExpander;
108 mutateAll( translationUnit, idxExpander );
109
110 TupleExprExpander exprExpander;
111 mutateAll( translationUnit, exprExpander );
112 }
113
114 namespace {
115 /// given a expression representing the member and an expression representing the aggregate,
116 /// reconstructs a flattened UntypedMemberExpr with the right precedence
117 Expression * reconstructMemberExpr( Expression * member, Expression * aggr ) {
118 if ( UntypedMemberExpr * memberExpr = dynamic_cast< UntypedMemberExpr * >( member ) ) {
119 // construct a new UntypedMemberExpr with the correct structure , and recursively
120 // expand that member expression.
121 MemberTupleExpander expander;
122 UntypedMemberExpr * newMemberExpr = new UntypedMemberExpr( memberExpr->get_member(), new UntypedMemberExpr( memberExpr->get_aggregate(), aggr->clone() ) );
123
124 memberExpr->set_member(nullptr);
125 memberExpr->set_aggregate(nullptr);
126 delete memberExpr;
127 return newMemberExpr->acceptMutator( expander );
128 } else {
129 // not a member expression, so there is nothing to do but attach and return
130 return new UntypedMemberExpr( member, aggr->clone() );
131 }
132 }
133 }
134
135 Expression * MemberTupleExpander::mutate( UntypedMemberExpr * memberExpr ) {
136 if ( TupleExpr * tupleExpr = dynamic_cast< TupleExpr * > ( memberExpr->get_member() ) ) {
137 Expression * aggr = memberExpr->get_aggregate()->clone()->acceptMutator( *this );
138 // aggregate expressions which might be impure must be wrapped in unique expressions
139 // 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
140 // if ( Tuples::maybeImpure( memberExpr->get_aggregate() ) ) aggr = new UniqueExpr( aggr );
141 aggr = new UniqueExpr( aggr );
142 for ( Expression *& expr : tupleExpr->get_exprs() ) {
143 expr = reconstructMemberExpr( expr, aggr );
144 }
145 delete aggr;
146 return tupleExpr;
147 } else {
148 // there may be a tuple expr buried in the aggregate
149 // xxx - this is a memory leak
150 return new UntypedMemberExpr( memberExpr->get_member()->clone(), memberExpr->get_aggregate()->acceptMutator( *this ) );
151 }
152 }
153
154 Expression * UniqueExprExpander::mutate( UniqueExpr * unqExpr ) {
155 unqExpr = safe_dynamic_cast< UniqueExpr * > ( Parent::mutate( unqExpr ) );
156 const int id = unqExpr->get_id();
157
158 // on first time visiting a unique expr with a particular ID, generate the expression that replaces all UniqueExprs with that ID,
159 // and lookup on subsequent hits. This ensures that all unique exprs with the same ID reference the same variable.
160 if ( ! decls.count( id ) ) {
161 Expression * assignUnq;
162 Expression * var = unqExpr->get_var();
163 if ( unqExpr->get_object() ) {
164 // an object was generated to represent this unique expression -- it should be added to the list of declarations now
165 addDeclaration( unqExpr->get_object() );
166 unqExpr->set_object( nullptr );
167 // steal the expr from the unqExpr
168 assignUnq = UntypedExpr::createAssign( unqExpr->get_var()->clone(), unqExpr->get_expr() );
169 unqExpr->set_expr( nullptr );
170 } else {
171 // steal the already generated assignment to var from the unqExpr - this has been generated by FixInit
172 Expression * expr = unqExpr->get_expr();
173 CommaExpr * commaExpr = safe_dynamic_cast< CommaExpr * >( expr );
174 assignUnq = commaExpr->get_arg1();
175 commaExpr->set_arg1( nullptr );
176 }
177 BasicType * boolType = new BasicType( Type::Qualifiers(), BasicType::Bool );
178 ObjectDecl * finished = new ObjectDecl( toString( "_unq_expr_finished_", id ), DeclarationNode::NoStorageClass, LinkageSpec::Cforall, nullptr, new BasicType( Type::Qualifiers(), BasicType::Bool ), new SingleInit( new ConstantExpr( Constant( boolType->clone(), "0" ) ), noDesignators ) );
179 addDeclaration( finished );
180 // (finished ? _unq_expr_N : (_unq_expr_N = <unqExpr->get_expr()>, finished = 1, _unq_expr_N))
181 // This pattern ensures that each unique expression is evaluated once, regardless of evaluation order of the generated C code.
182 Expression * assignFinished = UntypedExpr::createAssign( new VariableExpr(finished), new ConstantExpr( Constant( boolType->clone(), "1" ) ) );
183 ConditionalExpr * condExpr = new ConditionalExpr( new VariableExpr( finished ), var->clone(),
184 new CommaExpr( new CommaExpr( assignUnq, assignFinished ), var->clone() ) );
185 condExpr->set_result( var->get_result()->clone() );
186 decls[id] = condExpr;
187 }
188 delete unqExpr;
189 return decls[id]->clone();
190 }
191
192 Expression * TupleAssignExpander::mutate( TupleAssignExpr * assnExpr ) {
193 assnExpr = safe_dynamic_cast< TupleAssignExpr * >( Parent::mutate( assnExpr ) );
194 CompoundStmt * compoundStmt = new CompoundStmt( noLabels );
195 std::list< Statement * > & stmts = compoundStmt->get_kids();
196 for ( ObjectDecl * obj : assnExpr->get_tempDecls() ) {
197 stmts.push_back( new DeclStmt( noLabels, obj ) );
198 }
199 TupleExpr * tupleExpr = new TupleExpr( assnExpr->get_assigns() );
200 assert( tupleExpr->get_result() );
201 stmts.push_back( new ExprStmt( noLabels, tupleExpr ) );
202 assnExpr->get_tempDecls().clear();
203 assnExpr->get_assigns().clear();
204 delete assnExpr;
205 return new StmtExpr( compoundStmt );
206 }
207
208 Type * TupleTypeReplacer::mutate( TupleType * tupleType ) {
209 std::string mangleName = SymTab::Mangler::mangleType( tupleType );
210 TupleType * newType = safe_dynamic_cast< TupleType * > ( Parent::mutate( tupleType ) );
211 if ( ! typeMap.count( mangleName ) ) {
212 // generate struct type to replace tuple type
213 StructDecl * decl = new StructDecl( "_tuple_type_" + mangleName );
214 decl->set_body( true );
215 int cnt = 0;
216 for ( Type * t : *newType ) {
217 decl->get_members().push_back( new ObjectDecl( toString("field_", cnt++), DeclarationNode::NoStorageClass, LinkageSpec::C, nullptr, t->clone(), nullptr ) );
218 }
219 typeMap[mangleName] = decl;
220 addDeclaration( decl );
221 }
222 Type::Qualifiers qualifiers = newType->get_qualifiers();
223 delete newType;
224 return new StructInstType( qualifiers, typeMap[mangleName] );
225 }
226
227 Expression * TupleIndexExpander::mutate( TupleIndexExpr * tupleExpr ) {
228 Expression * tuple = maybeMutate( tupleExpr->get_tuple(), *this );
229 assert( tuple );
230 tupleExpr->set_tuple( nullptr );
231 unsigned int idx = tupleExpr->get_index();
232 delete tupleExpr;
233
234 StructInstType * type = safe_dynamic_cast< StructInstType * >( tuple->get_result() );
235 StructDecl * structDecl = type->get_baseStruct();
236 assert( structDecl->get_members().size() > idx );
237 Declaration * member = *std::next(structDecl->get_members().begin(), idx);
238 return new MemberExpr( safe_dynamic_cast< DeclarationWithType * >( member ), tuple );
239 }
240
241 Expression * replaceTupleExpr( Type * result, const std::list< Expression * > & exprs ) {
242 if ( result->isVoid() ) {
243 // void result - don't need to produce a value for cascading - just output a chain of comma exprs
244 assert( ! exprs.empty() );
245 std::list< Expression * >::const_iterator iter = exprs.begin();
246 Expression * expr = *iter++;
247 for ( ; iter != exprs.end(); ++iter ) {
248 expr = new CommaExpr( expr, *iter );
249 }
250 return expr;
251 } else {
252 // typed tuple expression - produce a compound literal which performs each of the expressions
253 // as a distinct part of its initializer - the produced compound literal may be used as part of
254 // another expression
255 std::list< Initializer * > inits;
256 for ( Expression * expr : exprs ) {
257 inits.push_back( new SingleInit( expr ) );
258 }
259 return new CompoundLiteralExpr( result, new ListInit( inits ) );
260 }
261 }
262
263 Expression * TupleExprExpander::mutate( TupleExpr * tupleExpr ) {
264 // recursively expand sub-tuple-expressions
265 tupleExpr = safe_dynamic_cast<TupleExpr *>(Parent::mutate(tupleExpr));
266 Type * result = tupleExpr->get_result();
267 std::list< Expression * > exprs = tupleExpr->get_exprs();
268 assert( result );
269
270 // remove data from shell and delete it
271 tupleExpr->set_result( nullptr );
272 tupleExpr->get_exprs().clear();
273 delete tupleExpr;
274
275 return replaceTupleExpr( result, exprs );
276 }
277
278 Type * makeTupleType( const std::list< Expression * > & exprs ) {
279 // produce the TupleType which aggregates the types of the exprs
280 TupleType *tupleType = new TupleType( Type::Qualifiers(true, true, true, true, true, false) );
281 Type::Qualifiers &qualifiers = tupleType->get_qualifiers();
282 for ( Expression * expr : exprs ) {
283 assert( expr->get_result() );
284 if ( expr->get_result()->isVoid() ) {
285 // if the type of any expr is void, the type of the entire tuple is void
286 delete tupleType;
287 return new VoidType( Type::Qualifiers() );
288 }
289 Type * type = expr->get_result()->clone();
290 tupleType->get_types().push_back( type );
291 // the qualifiers on the tuple type are the qualifiers that exist on all component types
292 qualifiers &= type->get_qualifiers();
293 } // for
294 return tupleType;
295 }
296
297 namespace {
298 /// 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
299 class ImpurityDetector : public Visitor {
300 public:
301 typedef Visitor Parent;
302 virtual void visit( ApplicationExpr * appExpr ) { maybeImpure = true; }
303 virtual void visit( UntypedExpr * untypedExpr ) { maybeImpure = true; }
304 bool maybeImpure = false;
305 };
306 } // namespace
307
308 bool maybeImpure( Expression * expr ) {
309 ImpurityDetector detector;
310 expr->accept( detector );
311 return detector.maybeImpure;
312 }
313} // namespace Tuples
314
315// Local Variables: //
316// tab-width: 4 //
317// mode: c++ //
318// compile-command: "make install" //
319// End: //
320
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