source: src/InitTweak/GenInit.cc@ 40e636a

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors ctor deferred_resn demangler enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox memory 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 40e636a was 40e636a, checked in by Rob Schluntz <rschlunt@…>, 9 years ago

only generate array dimension constant inside of functions, recursively mutate array types into pointer types in function parameter lists, fix bug where global compound literal object is lost
  • Property mode set to 100644
File size: 11.8 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// GenInit.cc --
8//
9// Author : Rob Schluntz
10// Created On : Mon May 18 07:44:20 2015
11// Last Modified By : Rob Schluntz
12// Last Modified On : Fri May 13 11:37:48 2016
13// Update Count : 166
14//
15
16#include <stack>
17#include <list>
18#include "GenInit.h"
19#include "InitTweak.h"
20#include "SynTree/Declaration.h"
21#include "SynTree/Type.h"
22#include "SynTree/Expression.h"
23#include "SynTree/Statement.h"
24#include "SynTree/Initializer.h"
25#include "SynTree/Mutator.h"
26#include "SymTab/Autogen.h"
27#include "GenPoly/PolyMutator.h"
28#include "GenPoly/DeclMutator.h"
29
30namespace InitTweak {
31 namespace {
32 const std::list<Label> noLabels;
33 const std::list<Expression *> noDesignators;
34 }
35
36 class ReturnFixer : public GenPoly::PolyMutator {
37 public:
38 /// consistently allocates a temporary variable for the return value
39 /// of a function so that anything which the resolver decides can be constructed
40 /// into the return type of a function can be returned.
41 static void makeReturnTemp( std::list< Declaration * > &translationUnit );
42
43 ReturnFixer();
44
45 virtual DeclarationWithType * mutate( FunctionDecl *functionDecl );
46
47 virtual Statement * mutate( ReturnStmt * returnStmt );
48
49 protected:
50 std::list<DeclarationWithType*> returnVals;
51 UniqueName tempNamer;
52 std::string funcName;
53 };
54
55 class CtorDtor : public GenPoly::PolyMutator {
56 public:
57 /// create constructor and destructor statements for object declarations.
58 /// the actual call statements will be added in after the resolver has run
59 /// so that the initializer expression is only removed if a constructor is found
60 /// and the same destructor call is inserted in all of the appropriate locations.
61 static void generateCtorDtor( std::list< Declaration * > &translationUnit );
62
63 CtorDtor() : inFunction( false ) {}
64
65 virtual DeclarationWithType * mutate( ObjectDecl * );
66 virtual DeclarationWithType * mutate( FunctionDecl *functionDecl );
67 // should not traverse into any of these declarations to find objects
68 // that need to be constructed or destructed
69 virtual Declaration* mutate( StructDecl *aggregateDecl ) { return aggregateDecl; }
70 virtual Declaration* mutate( UnionDecl *aggregateDecl ) { return aggregateDecl; }
71 virtual Declaration* mutate( EnumDecl *aggregateDecl ) { return aggregateDecl; }
72 virtual Declaration* mutate( TraitDecl *aggregateDecl ) { return aggregateDecl; }
73 virtual TypeDecl* mutate( TypeDecl *typeDecl ) { return typeDecl; }
74 virtual Declaration* mutate( TypedefDecl *typeDecl ) { return typeDecl; }
75
76 virtual Type * mutate( FunctionType *funcType ) { return funcType; }
77
78 protected:
79 bool inFunction;
80 };
81
82 class HoistArrayDimension : public GenPoly::DeclMutator {
83 public:
84 typedef GenPoly::DeclMutator Parent;
85
86 /// hoist dimension from array types in object declaration so that it uses a single
87 /// const variable of type size_t, so that side effecting array dimensions are only
88 /// computed once.
89 static void hoistArrayDimension( std::list< Declaration * > & translationUnit );
90
91 private:
92 virtual DeclarationWithType * mutate( ObjectDecl * objectDecl );
93 virtual DeclarationWithType * mutate( FunctionDecl *functionDecl );
94 // should not traverse into any of these declarations to find objects
95 // that need to be constructed or destructed
96 virtual Declaration* mutate( StructDecl *aggregateDecl ) { return aggregateDecl; }
97 virtual Declaration* mutate( UnionDecl *aggregateDecl ) { return aggregateDecl; }
98 virtual Declaration* mutate( EnumDecl *aggregateDecl ) { return aggregateDecl; }
99 virtual Declaration* mutate( TraitDecl *aggregateDecl ) { return aggregateDecl; }
100 virtual TypeDecl* mutate( TypeDecl *typeDecl ) { return typeDecl; }
101 virtual Declaration* mutate( TypedefDecl *typeDecl ) { return typeDecl; }
102
103 virtual Type* mutate( FunctionType *funcType ) { return funcType; }
104
105 void hoist( Type * type );
106
107 DeclarationNode::StorageClass storageclass = DeclarationNode::NoStorageClass;
108 bool inFunction = false;
109 };
110
111 void genInit( std::list< Declaration * > & translationUnit ) {
112 ReturnFixer::makeReturnTemp( translationUnit );
113 HoistArrayDimension::hoistArrayDimension( translationUnit );
114 CtorDtor::generateCtorDtor( translationUnit );
115 }
116
117 void ReturnFixer::makeReturnTemp( std::list< Declaration * > & translationUnit ) {
118 ReturnFixer fixer;
119 mutateAll( translationUnit, fixer );
120 }
121
122 ReturnFixer::ReturnFixer() : tempNamer( "_retVal" ) {}
123
124 Statement *ReturnFixer::mutate( ReturnStmt *returnStmt ) {
125 // update for multiple return values
126 assert( returnVals.size() == 0 || returnVals.size() == 1 );
127 // hands off if the function returns an lvalue - we don't want to allocate a temporary if a variable's address
128 // is being returned
129 if ( returnStmt->get_expr() && returnVals.size() == 1 && funcName != "?=?" && ! returnVals.front()->get_type()->get_isLvalue() ) {
130 // ensure return value is not destructed by explicitly creating
131 // an empty SingleInit node wherein maybeConstruct is false
132 ObjectDecl *newObj = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, returnVals.front()->get_type()->clone(), new ListInit( std::list<Initializer*>(), noDesignators, false ) );
133 stmtsToAdd.push_back( new DeclStmt( noLabels, newObj ) );
134
135 // and explicitly create the constructor expression separately
136 UntypedExpr *construct = new UntypedExpr( new NameExpr( "?{}" ) );
137 construct->get_args().push_back( new AddressExpr( new VariableExpr( newObj ) ) );
138 construct->get_args().push_back( returnStmt->get_expr() );
139 stmtsToAdd.push_back(new ExprStmt(noLabels, construct));
140
141 returnStmt->set_expr( new VariableExpr( newObj ) );
142 } // if
143 return returnStmt;
144 }
145
146 DeclarationWithType* ReturnFixer::mutate( FunctionDecl *functionDecl ) {
147 std::list<DeclarationWithType*> oldReturnVals = returnVals;
148 std::string oldFuncName = funcName;
149
150 FunctionType * type = functionDecl->get_functionType();
151 returnVals = type->get_returnVals();
152 funcName = functionDecl->get_name();
153 DeclarationWithType * decl = Mutator::mutate( functionDecl );
154 returnVals = oldReturnVals;
155 funcName = oldFuncName;
156 return decl;
157 }
158
159 void HoistArrayDimension::hoistArrayDimension( std::list< Declaration * > & translationUnit ) {
160 HoistArrayDimension hoister;
161 hoister.mutateDeclarationList( translationUnit );
162 }
163
164 DeclarationWithType * HoistArrayDimension::mutate( ObjectDecl * objectDecl ) {
165 storageclass = objectDecl->get_storageClass();
166 DeclarationWithType * temp = Parent::mutate( objectDecl );
167 hoist( objectDecl->get_type() );
168 storageclass = DeclarationNode::NoStorageClass;
169 return temp;
170 }
171
172 void HoistArrayDimension::hoist( Type * type ) {
173 // if in function, generate const size_t var
174 static UniqueName dimensionName( "_array_dim" );
175 if ( ArrayType * arrayType = dynamic_cast< ArrayType * >( type ) ) {
176 if ( ! inFunction ) return;
177
178 if ( ! arrayType->get_dimension() ) return; // xxx - recursive call to hoist?
179
180 // don't need to hoist dimension if it's a constexpr - only need to if there's potential
181 // for side effects.
182 if ( isConstExpr( arrayType->get_dimension() ) ) return;
183
184 ObjectDecl * arrayDimension = new ObjectDecl( dimensionName.newName(), storageclass, LinkageSpec::C, 0, SymTab::SizeType->clone(), new SingleInit( arrayType->get_dimension() ) );
185 arrayDimension->get_type()->set_isConst( true );
186
187 arrayType->set_dimension( new VariableExpr( arrayDimension ) );
188 addDeclaration( arrayDimension );
189
190 hoist( arrayType->get_base() );
191 return;
192 }
193 }
194
195 DeclarationWithType * HoistArrayDimension::mutate( FunctionDecl *functionDecl ) {
196 bool oldInFunc = inFunction;
197 inFunction = true;
198 DeclarationWithType * decl = Parent::mutate( functionDecl );
199 inFunction = oldInFunc;
200 return decl;
201 }
202
203 void CtorDtor::generateCtorDtor( std::list< Declaration * > & translationUnit ) {
204 CtorDtor ctordtor;
205 mutateAll( translationUnit, ctordtor );
206 }
207
208 namespace {
209 Expression * makeCtorDtorExpr( std::string name, ObjectDecl * objDecl, std::list< Expression * > args ) {
210 UntypedExpr * expr = new UntypedExpr( new NameExpr( name ) );
211 expr->get_args().push_back( new AddressExpr( new VariableExpr( objDecl ) ) );
212 expr->get_args().splice( expr->get_args().end(), args );
213 return expr;
214 }
215 }
216
217 DeclarationWithType * CtorDtor::mutate( ObjectDecl * objDecl ) {
218 // hands off if designated or if @=
219 if ( tryConstruct( objDecl ) ) {
220 if ( inFunction ) {
221 if ( ArrayType * at = dynamic_cast< ArrayType * >( objDecl->get_type() ) ) {
222 // call into makeArrayFunction from validate.cc to generate calls to ctor/dtor for each element of array
223 // TODO: walk initializers and generate appropriate ctor if element has initializer.
224 // Initializer could be nested (depends on the depth of the array type on the object)
225
226 std::list< Expression * > args = makeInitList( objDecl->get_init() );
227 if ( args.empty() ) {
228 std::list< Statement * > ctor;
229 std::list< Statement * > dtor;
230
231 SymTab::genImplicitCall( NULL, new VariableExpr( objDecl ), "?{}", back_inserter( ctor ), objDecl );
232 SymTab::genImplicitCall( NULL, new VariableExpr( objDecl ), "^?{}", front_inserter( dtor ), objDecl, false );
233
234 // Currently genArrayCall produces a single Statement - a CompoundStmt
235 // which wraps everything that needs to happen. As such, it's technically
236 // possible to use a Statement ** in the above calls, but this is inherently
237 // unsafe, so instead we take the slightly less efficient route, but will be
238 // immediately informed if somehow the above assumption is broken. In this case,
239 // we could always wrap the list of statements at this point with a CompoundStmt,
240 // but it seems reasonable at the moment for this to be done by genArrayCall
241 // itself
242 assert( ctor.size() == 1 && dynamic_cast< ImplicitCtorDtorStmt * >( ctor.front() ) );
243 assert( dtor.size() == 1 && dynamic_cast< ImplicitCtorDtorStmt * >( dtor.front() ) );
244 objDecl->set_init( new ConstructorInit( ctor.front(), dtor.front(), objDecl->get_init() ) );
245 } else {
246 // array came with an initializer list: initialize each element
247 // may have more initializers than elements in the array - need to check at each index that
248 // we haven't exceeded size. This requires precomputing the size because it might be a side-effecting
249 // computation.
250 // may have fewer initializers than elements in the array - need to default construct
251 // remaining elements.
252 // might be able to merge this with the case above.
253
254 }
255 } else {
256 // it's sufficient to attempt to call the ctor/dtor for the given object and its initializer
257 Expression * ctor = makeCtorDtorExpr( "?{}", objDecl, makeInitList( objDecl->get_init() ) );
258 Expression * dtor = makeCtorDtorExpr( "^?{}", objDecl, std::list< Expression * >() );
259
260 // need to remember init expression, in case no ctors exist
261 // if ctor does exist, want to use ctor expression instead of init
262 // push this decision to the resolver
263 ExprStmt * ctorStmt = new ExprStmt( noLabels, ctor );
264 ExprStmt * dtorStmt = new ExprStmt( noLabels, dtor );
265 objDecl->set_init( new ConstructorInit( new ImplicitCtorDtorStmt( ctorStmt ), new ImplicitCtorDtorStmt( dtorStmt ), objDecl->get_init() ) );
266 }
267 }
268 }
269 return Mutator::mutate( objDecl );
270 }
271
272 DeclarationWithType * CtorDtor::mutate( FunctionDecl *functionDecl ) {
273 // parameters should not be constructed and destructed, so don't mutate FunctionType
274 bool oldInFunc = inFunction;
275 mutateAll( functionDecl->get_oldDecls(), *this );
276 inFunction = true;
277 functionDecl->set_statements( maybeMutate( functionDecl->get_statements(), *this ) );
278 inFunction = oldInFunc;
279 return functionDecl;
280 }
281} // namespace InitTweak
282
283// Local Variables: //
284// tab-width: 4 //
285// mode: c++ //
286// compile-command: "make install" //
287// End: //
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