source: src/InitTweak/GenInit.cc @ 35b06a8

ADTaaron-thesisarm-ehast-experimentalcleanup-dtorsdeferred_resndemanglerenumforall-pointer-decayjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprnew-envno_listpersistent-indexerpthread-emulationqualifiedEnumresolv-newwith_gc
Last change on this file since 35b06a8 was 9ff56e7, checked in by Thierry Delisle <tdelisle@…>, 7 years ago

Removed several new warnings

  • Property mode set to 100644
File size: 14.7 KB
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[51587aa]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//
[a0fdbd5]7// GenInit.cc --
[51587aa]8//
[cf16f94]9// Author           : Rob Schluntz
[51587aa]10// Created On       : Mon May 18 07:44:20 2015
[3a5131ed]11// Last Modified By : Peter A. Buhr
[615a096]12// Last Modified On : Fri Mar 17 09:12:36 2017
13// Update Count     : 183
[51587aa]14//
[a08ba92]15
[974906e2]16#include <stack>
17#include <list>
[8ca3a72]18
[7b3f66b]19#include "InitTweak.h"
[8ca3a72]20#include "GenInit.h"
21
22#include "Common/PassVisitor.h"
23
24#include "GenPoly/DeclMutator.h"
25#include "GenPoly/PolyMutator.h"
26#include "GenPoly/ScopedSet.h"
27
28#include "ResolvExpr/typeops.h"
29
[42e2ad7]30#include "SynTree/Declaration.h"
31#include "SynTree/Expression.h"
32#include "SynTree/Initializer.h"
33#include "SynTree/Mutator.h"
[8ca3a72]34#include "SynTree/Statement.h"
35#include "SynTree/Type.h"
36
[620cb95]37#include "SymTab/Autogen.h"
[1ba88a0]38#include "SymTab/Mangler.h"
[42e2ad7]39
40namespace InitTweak {
[a08ba92]41        namespace {
42                const std::list<Label> noLabels;
[5b40f30]43                const std::list<Expression *> noDesignators;
[a08ba92]44        }
[1e9d87b]45
[d24d4e1]46        struct ReturnFixer : public WithStmtsToAdd, public WithGuards {
[a0fdbd5]47                /// consistently allocates a temporary variable for the return value
48                /// of a function so that anything which the resolver decides can be constructed
[02c7d04]49                /// into the return type of a function can be returned.
[a0fdbd5]50                static void makeReturnTemp( std::list< Declaration * > &translationUnit );
[02c7d04]51
[7b6ca2e]52                void premutate( FunctionDecl *functionDecl );
53                void premutate( ReturnStmt * returnStmt );
[1e9d87b]54
55          protected:
[65660bd]56                FunctionType * ftype;
[cf16f94]57                std::string funcName;
58        };
[42e2ad7]59
[d24d4e1]60        struct CtorDtor : public WithGuards, public WithShortCircuiting  {
[02c7d04]61                /// create constructor and destructor statements for object declarations.
[5f98ce5]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.
[02c7d04]65                static void generateCtorDtor( std::list< Declaration * > &translationUnit );
[974906e2]66
[d24d4e1]67                void previsit( ObjectDecl * );
68                void previsit( FunctionDecl *functionDecl );
69
[5f98ce5]70                // should not traverse into any of these declarations to find objects
71                // that need to be constructed or destructed
[d24d4e1]72                void previsit( StructDecl *aggregateDecl );
[9ff56e7]73                void previsit( __attribute__((unused)) UnionDecl    * aggregateDecl ) { visit_children = false; }
74                void previsit( __attribute__((unused)) EnumDecl     * aggregateDecl ) { visit_children = false; }
75                void previsit( __attribute__((unused)) TraitDecl    * aggregateDecl ) { visit_children = false; }
76                void previsit( __attribute__((unused)) TypeDecl     * typeDecl )      { visit_children = false; }
77                void previsit( __attribute__((unused)) TypedefDecl  * typeDecl )      { visit_children = false; }
78                void previsit( __attribute__((unused)) FunctionType * funcType )      { visit_children = false; }
[db4ecc5]79
[d24d4e1]80                void previsit( CompoundStmt * compoundStmt );
[1ba88a0]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
[65660bd]88                bool isManaged( Type * type ) const; // determine if type is managed
[1ba88a0]89                void handleDWT( DeclarationWithType * dwt ); // add type to managed if ctor/dtor
90                GenPoly::ScopedSet< std::string > managedTypes;
91                bool inFunction = false;
[974906e2]92        };
93
[62e5546]94        class HoistArrayDimension final : public GenPoly::DeclMutator {
[5f98ce5]95          public:
96                typedef GenPoly::DeclMutator Parent;
97
98                /// hoist dimension from array types in object declaration so that it uses a single
99                /// const variable of type size_t, so that side effecting array dimensions are only
100                /// computed once.
101                static void hoistArrayDimension( std::list< Declaration * > & translationUnit );
102
103          private:
[62e5546]104                using Parent::mutate;
105
106                virtual DeclarationWithType * mutate( ObjectDecl * objectDecl ) override;
107                virtual DeclarationWithType * mutate( FunctionDecl *functionDecl ) override;
[5f98ce5]108                // should not traverse into any of these declarations to find objects
109                // that need to be constructed or destructed
[62e5546]110                virtual Declaration* mutate( StructDecl *aggregateDecl ) override { return aggregateDecl; }
111                virtual Declaration* mutate( UnionDecl *aggregateDecl ) override { return aggregateDecl; }
112                virtual Declaration* mutate( EnumDecl *aggregateDecl ) override { return aggregateDecl; }
113                virtual Declaration* mutate( TraitDecl *aggregateDecl ) override { return aggregateDecl; }
114                virtual TypeDecl* mutate( TypeDecl *typeDecl ) override { return typeDecl; }
115                virtual Declaration* mutate( TypedefDecl *typeDecl ) override { return typeDecl; }
116
117                virtual Type* mutate( FunctionType *funcType ) override { return funcType; }
[5f98ce5]118
119                void hoist( Type * type );
120
[68fe077a]121                Type::StorageClasses storageClasses;
[40e636a]122                bool inFunction = false;
[5f98ce5]123        };
124
[a0fdbd5]125        void genInit( std::list< Declaration * > & translationUnit ) {
126                ReturnFixer::makeReturnTemp( translationUnit );
[5f98ce5]127                HoistArrayDimension::hoistArrayDimension( translationUnit );
[02c7d04]128                CtorDtor::generateCtorDtor( translationUnit );
129        }
130
[a0fdbd5]131        void ReturnFixer::makeReturnTemp( std::list< Declaration * > & translationUnit ) {
[7b6ca2e]132                PassVisitor<ReturnFixer> fixer;
[a0fdbd5]133                mutateAll( translationUnit, fixer );
[a08ba92]134        }
[42e2ad7]135
[7b6ca2e]136        void ReturnFixer::premutate( ReturnStmt *returnStmt ) {
[65660bd]137                std::list< DeclarationWithType * > & returnVals = ftype->get_returnVals();
[cf16f94]138                assert( returnVals.size() == 0 || returnVals.size() == 1 );
139                // hands off if the function returns an lvalue - we don't want to allocate a temporary if a variable's address
140                // is being returned
[a28bc02]141                if ( returnStmt->get_expr() && returnVals.size() == 1 && ! returnVals.front()->get_type()->get_lvalue() ) {
[cce9429]142                        // explicitly construct the return value using the return expression and the retVal object
143                        assertf( returnVals.front()->get_name() != "", "Function %s has unnamed return value\n", funcName.c_str() );
[5b40f30]144                        UntypedExpr *construct = new UntypedExpr( new NameExpr( "?{}" ) );
[cce9429]145                        construct->get_args().push_back( new AddressExpr( new VariableExpr( returnVals.front() ) ) );
[5b40f30]146                        construct->get_args().push_back( returnStmt->get_expr() );
[7b6ca2e]147                        stmtsToAddBefore.push_back(new ExprStmt(noLabels, construct));
[cf16f94]148
[cce9429]149                        // return the retVal object
150                        returnStmt->set_expr( new VariableExpr( returnVals.front() ) );
[cf16f94]151                } // if
152        }
153
[7b6ca2e]154        void ReturnFixer::premutate( FunctionDecl *functionDecl ) {
[4eb31f2b]155                GuardValue( ftype );
156                GuardValue( funcName );
[1e9d87b]157
[65660bd]158                ftype = functionDecl->get_functionType();
[cf16f94]159                funcName = functionDecl->get_name();
160        }
[974906e2]161
[4d2434a]162        // precompute array dimension expression, because constructor generation may duplicate it,
163        // which would be incorrect if it is a side-effecting computation.
[5f98ce5]164        void HoistArrayDimension::hoistArrayDimension( std::list< Declaration * > & translationUnit ) {
165                HoistArrayDimension hoister;
[40e636a]166                hoister.mutateDeclarationList( translationUnit );
[5f98ce5]167        }
168
169        DeclarationWithType * HoistArrayDimension::mutate( ObjectDecl * objectDecl ) {
[a7c90d4]170                storageClasses = objectDecl->get_storageClasses();
[5f98ce5]171                DeclarationWithType * temp = Parent::mutate( objectDecl );
172                hoist( objectDecl->get_type() );
173                return temp;
174        }
175
176        void HoistArrayDimension::hoist( Type * type ) {
[40e636a]177                // if in function, generate const size_t var
[5f98ce5]178                static UniqueName dimensionName( "_array_dim" );
[40e636a]179
[a7c90d4]180                // C doesn't allow variable sized arrays at global scope or for static variables, so don't hoist dimension.
[f9cebb5]181                if ( ! inFunction ) return;
[08d5507b]182                if ( storageClasses.is_static ) return;
[f9cebb5]183
184                if ( ArrayType * arrayType = dynamic_cast< ArrayType * >( type ) ) {
[5f98ce5]185                        if ( ! arrayType->get_dimension() ) return; // xxx - recursive call to hoist?
186
[a7c90d4]187                        // don't need to hoist dimension if it's a constexpr - only need to if there's potential for side effects.
[5f98ce5]188                        if ( isConstExpr( arrayType->get_dimension() ) ) return;
189
[a7c90d4]190                        ObjectDecl * arrayDimension = new ObjectDecl( dimensionName.newName(), storageClasses, LinkageSpec::C, 0, SymTab::SizeType->clone(), new SingleInit( arrayType->get_dimension() ) );
[615a096]191                        arrayDimension->get_type()->set_const( true );
[5f98ce5]192
193                        arrayType->set_dimension( new VariableExpr( arrayDimension ) );
194                        addDeclaration( arrayDimension );
195
196                        hoist( arrayType->get_base() );
197                        return;
198                }
199        }
[974906e2]200
[40e636a]201        DeclarationWithType * HoistArrayDimension::mutate( FunctionDecl *functionDecl ) {
[1ba88a0]202                ValueGuard< bool > oldInFunc( inFunction );
[40e636a]203                inFunction = true;
204                DeclarationWithType * decl = Parent::mutate( functionDecl );
205                return decl;
206        }
207
[02c7d04]208        void CtorDtor::generateCtorDtor( std::list< Declaration * > & translationUnit ) {
[d24d4e1]209                PassVisitor<CtorDtor> ctordtor;
210                acceptAll( translationUnit, ctordtor );
[974906e2]211        }
212
[65660bd]213        bool CtorDtor::isManaged( Type * type ) const {
[0b465a5]214                // need to clear and reset qualifiers when determining if a type is managed
215                ValueGuard< Type::Qualifiers > qualifiers( type->get_qualifiers() );
216                type->get_qualifiers() = Type::Qualifiers();
[ac9ca96]217                if ( TupleType * tupleType = dynamic_cast< TupleType * > ( type ) ) {
218                        // tuple is also managed if any of its components are managed
219                        if ( std::any_of( tupleType->get_types().begin(), tupleType->get_types().end(), [&](Type * type) { return isManaged( type ); }) ) {
220                                return true;
221                        }
222                }
[30b65d8]223                // a type is managed if it appears in the map of known managed types, or if it contains any polymorphism (is a type variable or generic type containing a type variable)
224                return managedTypes.find( SymTab::Mangler::mangle( type ) ) != managedTypes.end() || GenPoly::isPolyType( type );
[65660bd]225        }
226
[1ba88a0]227        bool CtorDtor::isManaged( ObjectDecl * objDecl ) const {
228                Type * type = objDecl->get_type();
229                while ( ArrayType * at = dynamic_cast< ArrayType * >( type ) ) {
230                        type = at->get_base();
231                }
[65660bd]232                return isManaged( type );
[1ba88a0]233        }
234
235        void CtorDtor::handleDWT( DeclarationWithType * dwt ) {
236                // if this function is a user-defined constructor or destructor, mark down the type as "managed"
237                if ( ! LinkageSpec::isOverridable( dwt->get_linkage() ) && isCtorDtor( dwt->get_name() ) ) {
238                        std::list< DeclarationWithType * > & params = GenPoly::getFunctionType( dwt->get_type() )->get_parameters();
239                        assert( ! params.empty() );
240                        PointerType * type = safe_dynamic_cast< PointerType * >( params.front()->get_type() );
241                        managedTypes.insert( SymTab::Mangler::mangle( type->get_base() ) );
242                }
243        }
244
[092528b]245        ImplicitCtorDtorStmt * genCtorDtor( const std::string & fname, ObjectDecl * objDecl, Expression * arg ) {
246                // call into genImplicitCall from Autogen.h to generate calls to ctor/dtor
247                assertf( objDecl, "genCtorDtor passed null objDecl" );
248                std::list< Statement * > stmts;
249                InitExpander srcParam( maybeClone( arg ) );
250                SymTab::genImplicitCall( srcParam, new VariableExpr( objDecl ), fname, back_inserter( stmts ), objDecl );
251                assert( stmts.size() <= 1 );
252                return stmts.size() == 1 ? safe_dynamic_cast< ImplicitCtorDtorStmt * >( stmts.front() ) : nullptr;
253        }
254
[f0121d7]255        ConstructorInit * genCtorInit( ObjectDecl * objDecl ) {
256                // call into genImplicitCall from Autogen.h to generate calls to ctor/dtor
257                // for each constructable object
258                std::list< Statement * > ctor;
259                std::list< Statement * > dtor;
260
261                InitExpander srcParam( objDecl->get_init() );
262                InitExpander nullParam( (Initializer *)NULL );
263                SymTab::genImplicitCall( srcParam, new VariableExpr( objDecl ), "?{}", back_inserter( ctor ), objDecl );
264                SymTab::genImplicitCall( nullParam, new VariableExpr( objDecl ), "^?{}", front_inserter( dtor ), objDecl, false );
265
266                // Currently genImplicitCall produces a single Statement - a CompoundStmt
267                // which  wraps everything that needs to happen. As such, it's technically
268                // possible to use a Statement ** in the above calls, but this is inherently
269                // unsafe, so instead we take the slightly less efficient route, but will be
270                // immediately informed if somehow the above assumption is broken. In this case,
271                // we could always wrap the list of statements at this point with a CompoundStmt,
272                // but it seems reasonable at the moment for this to be done by genImplicitCall
273                // itself. It is possible that genImplicitCall produces no statements (e.g. if
274                // an array type does not have a dimension). In this case, it's fine to ignore
275                // the object for the purposes of construction.
276                assert( ctor.size() == dtor.size() && ctor.size() <= 1 );
277                if ( ctor.size() == 1 ) {
278                        // need to remember init expression, in case no ctors exist
279                        // if ctor does exist, want to use ctor expression instead of init
280                        // push this decision to the resolver
281                        assert( dynamic_cast< ImplicitCtorDtorStmt * > ( ctor.front() ) && dynamic_cast< ImplicitCtorDtorStmt * > ( dtor.front() ) );
282                        return new ConstructorInit( ctor.front(), dtor.front(), objDecl->get_init() );
283                }
284                return nullptr;
285        }
286
[d24d4e1]287        void CtorDtor::previsit( ObjectDecl * objDecl ) {
[1ba88a0]288                handleDWT( objDecl );
289                // hands off if @=, extern, builtin, etc.
[a4dd728]290                // even if unmanaged, try to construct global or static if initializer is not constexpr, since this is not legal C
291                if ( tryConstruct( objDecl ) && ( isManaged( objDecl ) || ((! inFunction || objDecl->get_storageClasses().is_static ) && ! isConstExpr( objDecl->get_init() ) ) ) ) {
[1ba88a0]292                        // constructed objects cannot be designated
[a4dd728]293                        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 @=.\n", objDecl );
[dcd73d1]294                        // constructed objects should not have initializers nested too deeply
295                        if ( ! checkInitDepth( objDecl ) ) throw SemanticError( "Managed object's initializer is too deep ", objDecl );
[1ba88a0]296
[f0121d7]297                        objDecl->set_init( genCtorInit( objDecl ) );
[974906e2]298                }
299        }
300
[d24d4e1]301        void CtorDtor::previsit( FunctionDecl *functionDecl ) {
302                GuardValue( inFunction );
[1ba88a0]303                inFunction = true;
304
305                handleDWT( functionDecl );
306
[d24d4e1]307                GuardScope( managedTypes );
[1ba88a0]308                // go through assertions and recursively add seen ctor/dtors
[8c49c0e]309                for ( auto & tyDecl : functionDecl->get_functionType()->get_forall() ) {
[1ba88a0]310                        for ( DeclarationWithType *& assertion : tyDecl->get_assertions() ) {
[a8e64c4]311                                handleDWT( assertion );
[1ba88a0]312                        }
313                }
314
[d24d4e1]315                PassVisitor<CtorDtor> newCtorDtor;
316                newCtorDtor.pass = *this;
317                maybeAccept( functionDecl->get_statements(), newCtorDtor );
318                visit_children = false;  // do not try and construct parameters or forall parameters - must happen after maybeAccept
[02c7d04]319        }
[1ba88a0]320
[d24d4e1]321        void CtorDtor::previsit( StructDecl *aggregateDecl ) {
322                visit_children = false; // do not try to construct and destruct aggregate members
323
[1ba88a0]324                // don't construct members, but need to take note if there is a managed member,
325                // because that means that this type is also managed
326                for ( Declaration * member : aggregateDecl->get_members() ) {
327                        if ( ObjectDecl * field = dynamic_cast< ObjectDecl * >( member ) ) {
328                                if ( isManaged( field ) ) {
[23c4aa8]329                                        StructInstType inst( Type::Qualifiers(), aggregateDecl );
330                                        managedTypes.insert( SymTab::Mangler::mangle( &inst ) );
[1ba88a0]331                                        break;
332                                }
333                        }
334                }
335        }
336
[9ff56e7]337        void CtorDtor::previsit( __attribute__((unused)) CompoundStmt * compoundStmt ) {
[d24d4e1]338                GuardScope( managedTypes );
[1ba88a0]339        }
[42e2ad7]340} // namespace InitTweak
341
[51587aa]342// Local Variables: //
343// tab-width: 4 //
344// mode: c++ //
345// compile-command: "make install" //
346// End: //
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