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 "SymTab/Mangler.h" |
---|
28 | #include "GenPoly/PolyMutator.h" |
---|
29 | #include "GenPoly/DeclMutator.h" |
---|
30 | #include "GenPoly/ScopedSet.h" |
---|
31 | |
---|
32 | namespace InitTweak { |
---|
33 | namespace { |
---|
34 | const std::list<Label> noLabels; |
---|
35 | const std::list<Expression *> noDesignators; |
---|
36 | } |
---|
37 | |
---|
38 | class ReturnFixer : public GenPoly::PolyMutator { |
---|
39 | public: |
---|
40 | /// consistently allocates a temporary variable for the return value |
---|
41 | /// of a function so that anything which the resolver decides can be constructed |
---|
42 | /// into the return type of a function can be returned. |
---|
43 | static void makeReturnTemp( std::list< Declaration * > &translationUnit ); |
---|
44 | |
---|
45 | ReturnFixer(); |
---|
46 | |
---|
47 | virtual DeclarationWithType * mutate( FunctionDecl *functionDecl ); |
---|
48 | |
---|
49 | virtual Statement * mutate( ReturnStmt * returnStmt ); |
---|
50 | |
---|
51 | protected: |
---|
52 | std::list<DeclarationWithType*> returnVals; |
---|
53 | UniqueName tempNamer; |
---|
54 | std::string funcName; |
---|
55 | }; |
---|
56 | |
---|
57 | class CtorDtor : public GenPoly::PolyMutator { |
---|
58 | public: |
---|
59 | typedef GenPoly::PolyMutator Parent; |
---|
60 | using Parent::mutate; |
---|
61 | /// create constructor and destructor statements for object declarations. |
---|
62 | /// the actual call statements will be added in after the resolver has run |
---|
63 | /// so that the initializer expression is only removed if a constructor is found |
---|
64 | /// and the same destructor call is inserted in all of the appropriate locations. |
---|
65 | static void generateCtorDtor( std::list< Declaration * > &translationUnit ); |
---|
66 | |
---|
67 | virtual DeclarationWithType * mutate( ObjectDecl * ); |
---|
68 | virtual DeclarationWithType * mutate( FunctionDecl *functionDecl ); |
---|
69 | // should not traverse into any of these declarations to find objects |
---|
70 | // that need to be constructed or destructed |
---|
71 | virtual Declaration* mutate( StructDecl *aggregateDecl ); |
---|
72 | virtual Declaration* mutate( UnionDecl *aggregateDecl ) { return aggregateDecl; } |
---|
73 | virtual Declaration* mutate( EnumDecl *aggregateDecl ) { return aggregateDecl; } |
---|
74 | virtual Declaration* mutate( TraitDecl *aggregateDecl ) { return aggregateDecl; } |
---|
75 | virtual TypeDecl* mutate( TypeDecl *typeDecl ) { return typeDecl; } |
---|
76 | virtual Declaration* mutate( TypedefDecl *typeDecl ) { return typeDecl; } |
---|
77 | |
---|
78 | virtual Type * mutate( FunctionType *funcType ) { return funcType; } |
---|
79 | |
---|
80 | virtual CompoundStmt * mutate( CompoundStmt * compoundStmt ); |
---|
81 | |
---|
82 | private: |
---|
83 | // set of mangled type names for which a constructor or destructor exists in the current scope. |
---|
84 | // these types require a ConstructorInit node to be generated, anything else is a POD type and thus |
---|
85 | // should not have a ConstructorInit generated. |
---|
86 | |
---|
87 | bool isManaged( ObjectDecl * objDecl ) const ; // determine if object is managed |
---|
88 | void handleDWT( DeclarationWithType * dwt ); // add type to managed if ctor/dtor |
---|
89 | GenPoly::ScopedSet< std::string > managedTypes; |
---|
90 | bool inFunction = false; |
---|
91 | }; |
---|
92 | |
---|
93 | class HoistArrayDimension : public GenPoly::DeclMutator { |
---|
94 | public: |
---|
95 | typedef GenPoly::DeclMutator Parent; |
---|
96 | |
---|
97 | /// hoist dimension from array types in object declaration so that it uses a single |
---|
98 | /// const variable of type size_t, so that side effecting array dimensions are only |
---|
99 | /// computed once. |
---|
100 | static void hoistArrayDimension( std::list< Declaration * > & translationUnit ); |
---|
101 | |
---|
102 | private: |
---|
103 | virtual DeclarationWithType * mutate( ObjectDecl * objectDecl ); |
---|
104 | virtual DeclarationWithType * mutate( FunctionDecl *functionDecl ); |
---|
105 | // should not traverse into any of these declarations to find objects |
---|
106 | // that need to be constructed or destructed |
---|
107 | virtual Declaration* mutate( StructDecl *aggregateDecl ) { return aggregateDecl; } |
---|
108 | virtual Declaration* mutate( UnionDecl *aggregateDecl ) { return aggregateDecl; } |
---|
109 | virtual Declaration* mutate( EnumDecl *aggregateDecl ) { return aggregateDecl; } |
---|
110 | virtual Declaration* mutate( TraitDecl *aggregateDecl ) { return aggregateDecl; } |
---|
111 | virtual TypeDecl* mutate( TypeDecl *typeDecl ) { return typeDecl; } |
---|
112 | virtual Declaration* mutate( TypedefDecl *typeDecl ) { return typeDecl; } |
---|
113 | |
---|
114 | virtual Type* mutate( FunctionType *funcType ) { return funcType; } |
---|
115 | |
---|
116 | void hoist( Type * type ); |
---|
117 | |
---|
118 | DeclarationNode::StorageClass storageclass = DeclarationNode::NoStorageClass; |
---|
119 | bool inFunction = false; |
---|
120 | }; |
---|
121 | |
---|
122 | void genInit( std::list< Declaration * > & translationUnit ) { |
---|
123 | ReturnFixer::makeReturnTemp( translationUnit ); |
---|
124 | HoistArrayDimension::hoistArrayDimension( translationUnit ); |
---|
125 | CtorDtor::generateCtorDtor( translationUnit ); |
---|
126 | } |
---|
127 | |
---|
128 | void ReturnFixer::makeReturnTemp( std::list< Declaration * > & translationUnit ) { |
---|
129 | ReturnFixer fixer; |
---|
130 | mutateAll( translationUnit, fixer ); |
---|
131 | } |
---|
132 | |
---|
133 | ReturnFixer::ReturnFixer() : tempNamer( "_retVal" ) {} |
---|
134 | |
---|
135 | Statement *ReturnFixer::mutate( ReturnStmt *returnStmt ) { |
---|
136 | // update for multiple return values |
---|
137 | assert( returnVals.size() == 0 || returnVals.size() == 1 ); |
---|
138 | // hands off if the function returns an lvalue - we don't want to allocate a temporary if a variable's address |
---|
139 | // is being returned |
---|
140 | if ( returnStmt->get_expr() && returnVals.size() == 1 && funcName != "?=?" && ! returnVals.front()->get_type()->get_isLvalue() ) { |
---|
141 | // ensure return value is not destructed by explicitly creating |
---|
142 | // an empty SingleInit node wherein maybeConstruct is false |
---|
143 | ObjectDecl *newObj = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, returnVals.front()->get_type()->clone(), new ListInit( std::list<Initializer*>(), noDesignators, false ) ); |
---|
144 | stmtsToAdd.push_back( new DeclStmt( noLabels, newObj ) ); |
---|
145 | |
---|
146 | // and explicitly create the constructor expression separately |
---|
147 | UntypedExpr *construct = new UntypedExpr( new NameExpr( "?{}" ) ); |
---|
148 | construct->get_args().push_back( new AddressExpr( new VariableExpr( newObj ) ) ); |
---|
149 | construct->get_args().push_back( returnStmt->get_expr() ); |
---|
150 | stmtsToAdd.push_back(new ExprStmt(noLabels, construct)); |
---|
151 | |
---|
152 | returnStmt->set_expr( new VariableExpr( newObj ) ); |
---|
153 | } // if |
---|
154 | return returnStmt; |
---|
155 | } |
---|
156 | |
---|
157 | DeclarationWithType* ReturnFixer::mutate( FunctionDecl *functionDecl ) { |
---|
158 | ValueGuard< std::list<DeclarationWithType*> > oldReturnVals( returnVals ); |
---|
159 | ValueGuard< std::string > oldFuncName( funcName ); |
---|
160 | |
---|
161 | FunctionType * type = functionDecl->get_functionType(); |
---|
162 | returnVals = type->get_returnVals(); |
---|
163 | funcName = functionDecl->get_name(); |
---|
164 | DeclarationWithType * decl = Mutator::mutate( functionDecl ); |
---|
165 | return decl; |
---|
166 | } |
---|
167 | |
---|
168 | // precompute array dimension expression, because constructor generation may duplicate it, |
---|
169 | // which would be incorrect if it is a side-effecting computation. |
---|
170 | void HoistArrayDimension::hoistArrayDimension( std::list< Declaration * > & translationUnit ) { |
---|
171 | HoistArrayDimension hoister; |
---|
172 | hoister.mutateDeclarationList( translationUnit ); |
---|
173 | } |
---|
174 | |
---|
175 | DeclarationWithType * HoistArrayDimension::mutate( ObjectDecl * objectDecl ) { |
---|
176 | storageclass = objectDecl->get_storageClass(); |
---|
177 | DeclarationWithType * temp = Parent::mutate( objectDecl ); |
---|
178 | hoist( objectDecl->get_type() ); |
---|
179 | storageclass = DeclarationNode::NoStorageClass; |
---|
180 | return temp; |
---|
181 | } |
---|
182 | |
---|
183 | void HoistArrayDimension::hoist( Type * type ) { |
---|
184 | // if in function, generate const size_t var |
---|
185 | static UniqueName dimensionName( "_array_dim" ); |
---|
186 | |
---|
187 | // C doesn't allow variable sized arrays at global scope or for static variables, |
---|
188 | // so don't hoist dimension. |
---|
189 | if ( ! inFunction ) return; |
---|
190 | if ( storageclass == DeclarationNode::Static ) return; |
---|
191 | |
---|
192 | if ( ArrayType * arrayType = dynamic_cast< ArrayType * >( type ) ) { |
---|
193 | if ( ! arrayType->get_dimension() ) return; // xxx - recursive call to hoist? |
---|
194 | |
---|
195 | // don't need to hoist dimension if it's a constexpr - only need to if there's potential |
---|
196 | // for side effects. |
---|
197 | if ( isConstExpr( arrayType->get_dimension() ) ) return; |
---|
198 | |
---|
199 | ObjectDecl * arrayDimension = new ObjectDecl( dimensionName.newName(), storageclass, LinkageSpec::C, 0, SymTab::SizeType->clone(), new SingleInit( arrayType->get_dimension() ) ); |
---|
200 | arrayDimension->get_type()->set_isConst( true ); |
---|
201 | |
---|
202 | arrayType->set_dimension( new VariableExpr( arrayDimension ) ); |
---|
203 | addDeclaration( arrayDimension ); |
---|
204 | |
---|
205 | hoist( arrayType->get_base() ); |
---|
206 | return; |
---|
207 | } |
---|
208 | } |
---|
209 | |
---|
210 | DeclarationWithType * HoistArrayDimension::mutate( FunctionDecl *functionDecl ) { |
---|
211 | ValueGuard< bool > oldInFunc( inFunction ); |
---|
212 | inFunction = true; |
---|
213 | DeclarationWithType * decl = Parent::mutate( functionDecl ); |
---|
214 | return decl; |
---|
215 | } |
---|
216 | |
---|
217 | void CtorDtor::generateCtorDtor( std::list< Declaration * > & translationUnit ) { |
---|
218 | CtorDtor ctordtor; |
---|
219 | mutateAll( translationUnit, ctordtor ); |
---|
220 | } |
---|
221 | |
---|
222 | bool CtorDtor::isManaged( ObjectDecl * objDecl ) const { |
---|
223 | Type * type = objDecl->get_type(); |
---|
224 | while ( ArrayType * at = dynamic_cast< ArrayType * >( type ) ) { |
---|
225 | type = at->get_base(); |
---|
226 | } |
---|
227 | return managedTypes.find( SymTab::Mangler::mangle( type ) ) != managedTypes.end(); |
---|
228 | } |
---|
229 | |
---|
230 | void CtorDtor::handleDWT( DeclarationWithType * dwt ) { |
---|
231 | // if this function is a user-defined constructor or destructor, mark down the type as "managed" |
---|
232 | if ( ! LinkageSpec::isOverridable( dwt->get_linkage() ) && isCtorDtor( dwt->get_name() ) ) { |
---|
233 | std::list< DeclarationWithType * > & params = GenPoly::getFunctionType( dwt->get_type() )->get_parameters(); |
---|
234 | assert( ! params.empty() ); |
---|
235 | PointerType * type = safe_dynamic_cast< PointerType * >( params.front()->get_type() ); |
---|
236 | managedTypes.insert( SymTab::Mangler::mangle( type->get_base() ) ); |
---|
237 | } |
---|
238 | } |
---|
239 | |
---|
240 | DeclarationWithType * CtorDtor::mutate( ObjectDecl * objDecl ) { |
---|
241 | handleDWT( objDecl ); |
---|
242 | // hands off if @=, extern, builtin, etc. |
---|
243 | // if global but initializer is not constexpr, always try to construct, since this is not legal C |
---|
244 | if ( ( tryConstruct( objDecl ) && isManaged( objDecl ) ) || (! inFunction && ! isConstExpr( objDecl->get_init() ) ) ) { |
---|
245 | // constructed objects cannot be designated |
---|
246 | if ( isDesignated( objDecl->get_init() ) ) throw SemanticError( "Cannot include designations in the initializer for a managed Object. If this is really what you want, then initialize with @=.", objDecl ); |
---|
247 | // constructed objects should not have initializers nested too deeply |
---|
248 | if ( ! checkInitDepth( objDecl ) ) throw SemanticError( "Managed object's initializer is too deep ", objDecl ); |
---|
249 | |
---|
250 | // call into genImplicitCall from Autogen.h to generate calls to ctor/dtor |
---|
251 | // for each constructable object |
---|
252 | std::list< Statement * > ctor; |
---|
253 | std::list< Statement * > dtor; |
---|
254 | |
---|
255 | InitExpander srcParam( objDecl->get_init() ); |
---|
256 | InitExpander nullParam( (Initializer *)NULL ); |
---|
257 | SymTab::genImplicitCall( srcParam, new VariableExpr( objDecl ), "?{}", back_inserter( ctor ), objDecl ); |
---|
258 | SymTab::genImplicitCall( nullParam, new VariableExpr( objDecl ), "^?{}", front_inserter( dtor ), objDecl, false ); |
---|
259 | |
---|
260 | // Currently genImplicitCall produces a single Statement - a CompoundStmt |
---|
261 | // which wraps everything that needs to happen. As such, it's technically |
---|
262 | // possible to use a Statement ** in the above calls, but this is inherently |
---|
263 | // unsafe, so instead we take the slightly less efficient route, but will be |
---|
264 | // immediately informed if somehow the above assumption is broken. In this case, |
---|
265 | // we could always wrap the list of statements at this point with a CompoundStmt, |
---|
266 | // but it seems reasonable at the moment for this to be done by genImplicitCall |
---|
267 | // itself. It is possible that genImplicitCall produces no statements (e.g. if |
---|
268 | // an array type does not have a dimension). In this case, it's fine to ignore |
---|
269 | // the object for the purposes of construction. |
---|
270 | assert( ctor.size() == dtor.size() && ctor.size() <= 1 ); |
---|
271 | if ( ctor.size() == 1 ) { |
---|
272 | // need to remember init expression, in case no ctors exist |
---|
273 | // if ctor does exist, want to use ctor expression instead of init |
---|
274 | // push this decision to the resolver |
---|
275 | assert( dynamic_cast< ImplicitCtorDtorStmt * > ( ctor.front() ) && dynamic_cast< ImplicitCtorDtorStmt * > ( dtor.front() ) ); |
---|
276 | objDecl->set_init( new ConstructorInit( ctor.front(), dtor.front(), objDecl->get_init() ) ); |
---|
277 | } |
---|
278 | } |
---|
279 | return Parent::mutate( objDecl ); |
---|
280 | } |
---|
281 | |
---|
282 | DeclarationWithType * CtorDtor::mutate( FunctionDecl *functionDecl ) { |
---|
283 | ValueGuard< bool > oldInFunc = inFunction; |
---|
284 | inFunction = true; |
---|
285 | |
---|
286 | handleDWT( functionDecl ); |
---|
287 | |
---|
288 | managedTypes.beginScope(); |
---|
289 | // go through assertions and recursively add seen ctor/dtors |
---|
290 | for ( auto & tyDecl : functionDecl->get_functionType()->get_forall() ) { |
---|
291 | for ( DeclarationWithType *& assertion : tyDecl->get_assertions() ) { |
---|
292 | assertion = assertion->acceptMutator( *this ); |
---|
293 | } |
---|
294 | } |
---|
295 | // parameters should not be constructed and destructed, so don't mutate FunctionType |
---|
296 | mutateAll( functionDecl->get_oldDecls(), *this ); |
---|
297 | functionDecl->set_statements( maybeMutate( functionDecl->get_statements(), *this ) ); |
---|
298 | |
---|
299 | managedTypes.endScope(); |
---|
300 | return functionDecl; |
---|
301 | } |
---|
302 | |
---|
303 | Declaration* CtorDtor::mutate( StructDecl *aggregateDecl ) { |
---|
304 | // don't construct members, but need to take note if there is a managed member, |
---|
305 | // because that means that this type is also managed |
---|
306 | for ( Declaration * member : aggregateDecl->get_members() ) { |
---|
307 | if ( ObjectDecl * field = dynamic_cast< ObjectDecl * >( member ) ) { |
---|
308 | if ( isManaged( field ) ) { |
---|
309 | managedTypes.insert( SymTab::Mangler::mangle( aggregateDecl ) ); |
---|
310 | break; |
---|
311 | } |
---|
312 | } |
---|
313 | } |
---|
314 | return aggregateDecl; |
---|
315 | } |
---|
316 | |
---|
317 | CompoundStmt * CtorDtor::mutate( CompoundStmt * compoundStmt ) { |
---|
318 | managedTypes.beginScope(); |
---|
319 | CompoundStmt * stmt = Parent::mutate( compoundStmt ); |
---|
320 | managedTypes.endScope(); |
---|
321 | return stmt; |
---|
322 | } |
---|
323 | |
---|
324 | } // namespace InitTweak |
---|
325 | |
---|
326 | // Local Variables: // |
---|
327 | // tab-width: 4 // |
---|
328 | // mode: c++ // |
---|
329 | // compile-command: "make install" // |
---|
330 | // End: // |
---|