source: src/InitTweak/GenInit.cc@ 7ecbb7e

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 7ecbb7e was f9cebb5, checked in by Rob Schluntz <rschlunt@…>, 9 years ago

add gcc attributes to ObjectDecl, hoist destructed static variables, add breaks to end of generated switch
  • Property mode set to 100644
File size: 10.6 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 virtual DeclarationWithType * mutate( ObjectDecl * );
64 virtual DeclarationWithType * mutate( FunctionDecl *functionDecl );
65 // should not traverse into any of these declarations to find objects
66 // that need to be constructed or destructed
67 virtual Declaration* mutate( StructDecl *aggregateDecl ) { return aggregateDecl; }
68 virtual Declaration* mutate( UnionDecl *aggregateDecl ) { return aggregateDecl; }
69 virtual Declaration* mutate( EnumDecl *aggregateDecl ) { return aggregateDecl; }
70 virtual Declaration* mutate( TraitDecl *aggregateDecl ) { return aggregateDecl; }
71 virtual TypeDecl* mutate( TypeDecl *typeDecl ) { return typeDecl; }
72 virtual Declaration* mutate( TypedefDecl *typeDecl ) { return typeDecl; }
73
74 virtual Type * mutate( FunctionType *funcType ) { return funcType; }
75
76 protected:
77 };
78
79 class HoistArrayDimension : public GenPoly::DeclMutator {
80 public:
81 typedef GenPoly::DeclMutator Parent;
82
83 /// hoist dimension from array types in object declaration so that it uses a single
84 /// const variable of type size_t, so that side effecting array dimensions are only
85 /// computed once.
86 static void hoistArrayDimension( std::list< Declaration * > & translationUnit );
87
88 private:
89 virtual DeclarationWithType * mutate( ObjectDecl * objectDecl );
90 virtual DeclarationWithType * mutate( FunctionDecl *functionDecl );
91 // should not traverse into any of these declarations to find objects
92 // that need to be constructed or destructed
93 virtual Declaration* mutate( StructDecl *aggregateDecl ) { return aggregateDecl; }
94 virtual Declaration* mutate( UnionDecl *aggregateDecl ) { return aggregateDecl; }
95 virtual Declaration* mutate( EnumDecl *aggregateDecl ) { return aggregateDecl; }
96 virtual Declaration* mutate( TraitDecl *aggregateDecl ) { return aggregateDecl; }
97 virtual TypeDecl* mutate( TypeDecl *typeDecl ) { return typeDecl; }
98 virtual Declaration* mutate( TypedefDecl *typeDecl ) { return typeDecl; }
99
100 virtual Type* mutate( FunctionType *funcType ) { return funcType; }
101
102 void hoist( Type * type );
103
104 DeclarationNode::StorageClass storageclass = DeclarationNode::NoStorageClass;
105 bool inFunction = false;
106 };
107
108 void genInit( std::list< Declaration * > & translationUnit ) {
109 ReturnFixer::makeReturnTemp( translationUnit );
110 HoistArrayDimension::hoistArrayDimension( translationUnit );
111 CtorDtor::generateCtorDtor( translationUnit );
112 }
113
114 void ReturnFixer::makeReturnTemp( std::list< Declaration * > & translationUnit ) {
115 ReturnFixer fixer;
116 mutateAll( translationUnit, fixer );
117 }
118
119 ReturnFixer::ReturnFixer() : tempNamer( "_retVal" ) {}
120
121 Statement *ReturnFixer::mutate( ReturnStmt *returnStmt ) {
122 // update for multiple return values
123 assert( returnVals.size() == 0 || returnVals.size() == 1 );
124 // hands off if the function returns an lvalue - we don't want to allocate a temporary if a variable's address
125 // is being returned
126 if ( returnStmt->get_expr() && returnVals.size() == 1 && funcName != "?=?" && ! returnVals.front()->get_type()->get_isLvalue() ) {
127 // ensure return value is not destructed by explicitly creating
128 // an empty SingleInit node wherein maybeConstruct is false
129 ObjectDecl *newObj = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, returnVals.front()->get_type()->clone(), new ListInit( std::list<Initializer*>(), noDesignators, false ) );
130 stmtsToAdd.push_back( new DeclStmt( noLabels, newObj ) );
131
132 // and explicitly create the constructor expression separately
133 UntypedExpr *construct = new UntypedExpr( new NameExpr( "?{}" ) );
134 construct->get_args().push_back( new AddressExpr( new VariableExpr( newObj ) ) );
135 construct->get_args().push_back( returnStmt->get_expr() );
136 stmtsToAdd.push_back(new ExprStmt(noLabels, construct));
137
138 returnStmt->set_expr( new VariableExpr( newObj ) );
139 } // if
140 return returnStmt;
141 }
142
143 DeclarationWithType* ReturnFixer::mutate( FunctionDecl *functionDecl ) {
144 std::list<DeclarationWithType*> oldReturnVals = returnVals;
145 std::string oldFuncName = funcName;
146
147 FunctionType * type = functionDecl->get_functionType();
148 returnVals = type->get_returnVals();
149 funcName = functionDecl->get_name();
150 DeclarationWithType * decl = Mutator::mutate( functionDecl );
151 returnVals = oldReturnVals;
152 funcName = oldFuncName;
153 return decl;
154 }
155
156 // precompute array dimension expression, because constructor generation may duplicate it,
157 // which would be incorrect if it is a side-effecting computation.
158 void HoistArrayDimension::hoistArrayDimension( std::list< Declaration * > & translationUnit ) {
159 HoistArrayDimension hoister;
160 hoister.mutateDeclarationList( translationUnit );
161 }
162
163 DeclarationWithType * HoistArrayDimension::mutate( ObjectDecl * objectDecl ) {
164 storageclass = objectDecl->get_storageClass();
165 DeclarationWithType * temp = Parent::mutate( objectDecl );
166 hoist( objectDecl->get_type() );
167 storageclass = DeclarationNode::NoStorageClass;
168 return temp;
169 }
170
171 void HoistArrayDimension::hoist( Type * type ) {
172 // if in function, generate const size_t var
173 static UniqueName dimensionName( "_array_dim" );
174
175 // C doesn't allow variable sized arrays at global scope or for static variables,
176 // so don't hoist dimension.
177 if ( ! inFunction ) return;
178 if ( storageclass == DeclarationNode::Static ) return;
179
180 if ( ArrayType * arrayType = dynamic_cast< ArrayType * >( type ) ) {
181 if ( ! arrayType->get_dimension() ) return; // xxx - recursive call to hoist?
182
183 // don't need to hoist dimension if it's a constexpr - only need to if there's potential
184 // for side effects.
185 if ( isConstExpr( arrayType->get_dimension() ) ) return;
186
187 ObjectDecl * arrayDimension = new ObjectDecl( dimensionName.newName(), storageclass, LinkageSpec::C, 0, SymTab::SizeType->clone(), new SingleInit( arrayType->get_dimension() ) );
188 arrayDimension->get_type()->set_isConst( true );
189
190 arrayType->set_dimension( new VariableExpr( arrayDimension ) );
191 addDeclaration( arrayDimension );
192
193 hoist( arrayType->get_base() );
194 return;
195 }
196 }
197
198 DeclarationWithType * HoistArrayDimension::mutate( FunctionDecl *functionDecl ) {
199 bool oldInFunc = inFunction;
200 inFunction = true;
201 DeclarationWithType * decl = Parent::mutate( functionDecl );
202 inFunction = oldInFunc;
203 return decl;
204 }
205
206 void CtorDtor::generateCtorDtor( std::list< Declaration * > & translationUnit ) {
207 CtorDtor ctordtor;
208 mutateAll( translationUnit, ctordtor );
209 }
210
211 DeclarationWithType * CtorDtor::mutate( ObjectDecl * objDecl ) {
212 // hands off if designated, if @=, or if extern
213 if ( tryConstruct( objDecl ) ) {
214 // call into genImplicitCall from Autogen.h to generate calls to ctor/dtor
215 // for each constructable object
216 std::list< Statement * > ctor;
217 std::list< Statement * > dtor;
218
219 InitExpander srcParam( objDecl->get_init() );
220 InitExpander nullParam( (Initializer *)NULL );
221 SymTab::genImplicitCall( srcParam, new VariableExpr( objDecl ), "?{}", back_inserter( ctor ), objDecl );
222 SymTab::genImplicitCall( nullParam, new VariableExpr( objDecl ), "^?{}", front_inserter( dtor ), objDecl, false );
223
224 // Currently genImplicitCall produces a single Statement - a CompoundStmt
225 // which wraps everything that needs to happen. As such, it's technically
226 // possible to use a Statement ** in the above calls, but this is inherently
227 // unsafe, so instead we take the slightly less efficient route, but will be
228 // immediately informed if somehow the above assumption is broken. In this case,
229 // we could always wrap the list of statements at this point with a CompoundStmt,
230 // but it seems reasonable at the moment for this to be done by genImplicitCall
231 // itself. It is possible that genImplicitCall produces no statements (e.g. if
232 // an array type does not have a dimension). In this case, it's fine to ignore
233 // the object for the purposes of construction.
234 assert( ctor.size() == dtor.size() && ctor.size() <= 1 );
235 if ( ctor.size() == 1 ) {
236 // need to remember init expression, in case no ctors exist
237 // if ctor does exist, want to use ctor expression instead of init
238 // push this decision to the resolver
239 assert( dynamic_cast< ImplicitCtorDtorStmt * > ( ctor.front() ) && dynamic_cast< ImplicitCtorDtorStmt * > ( dtor.front() ) );
240 objDecl->set_init( new ConstructorInit( ctor.front(), dtor.front(), objDecl->get_init() ) );
241 }
242 }
243 return Mutator::mutate( objDecl );
244 }
245
246 DeclarationWithType * CtorDtor::mutate( FunctionDecl *functionDecl ) {
247 // parameters should not be constructed and destructed, so don't mutate FunctionType
248 mutateAll( functionDecl->get_oldDecls(), *this );
249 functionDecl->set_statements( maybeMutate( functionDecl->get_statements(), *this ) );
250 return functionDecl;
251 }
252} // namespace InitTweak
253
254// Local Variables: //
255// tab-width: 4 //
256// mode: c++ //
257// compile-command: "make install" //
258// End: //
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