Changes in src/InitTweak/FixInit.cc [ddae809:88e79ad]

File:

• src/InitTweak/FixInit.cc (modified) (15 diffs)

src/InitTweak/FixInit.cc

@@ -54 +54 @@
 #include "SynTree/Type.h"              // for Type, Type::StorageClasses
 #include "SynTree/TypeSubstitution.h"  // for TypeSubstitution, operator<<
+#include "SynTree/VarExprReplacer.h"   // for VarExprReplacer
 #include "SynTree/Visitor.h"           // for acceptAll, maybeAccept
 
@@ -158 +159 @@
                         using Parent::previsit;
 
-                        void previsit( ObjectDecl * objDecl );
                         void previsit( FunctionDecl * funcDecl );
 
-                        void previsit( CompoundStmt * compoundStmt );
-                        void postvisit( CompoundStmt * compoundStmt );
-                        void previsit( ReturnStmt * returnStmt );
                         void previsit( BranchStmt * stmt );
                 private:
@@ -203 +200 @@
                         static void generate( std::list< Declaration * > & translationUnit );
 
+                        void previsit( StructDecl * structDecl );
+
                         void previsit( FunctionDecl * funcDecl );
                         void postvisit( FunctionDecl * funcDecl );
@@ -220 +219 @@
                         bool isCtor = false; // true if current function is a constructor
                         StructDecl * structDecl = nullptr;
+
+                        // special built-in functions necessary for this to work
+                        StructDecl * dtorStruct = nullptr;
+                        FunctionDecl * dtorStructDestroy = nullptr;
                 };
 
@@ -501 +504 @@
                 }
 
-                // to prevent warnings (‘_unq0’ may be used uninitialized in this function),
-                // insert an appropriate zero initializer for UniqueExpr temporaries.
-                Initializer * makeInit( Type * t ) {
-                        if ( StructInstType * inst = dynamic_cast< StructInstType * >( t ) ) {
-                                // initizer for empty struct must be empty
-                                if ( inst->baseStruct->members.empty() ) return new ListInit({});
-                        } else if ( UnionInstType * inst = dynamic_cast< UnionInstType * >( t ) ) {
-                                // initizer for empty union must be empty
-                                if ( inst->baseUnion->members.empty() ) return new ListInit({});
-                        }
-
-                        return new ListInit( { new SingleInit( new ConstantExpr( Constant::from_int( 0 ) ) ) } );
-                }
-
                 void ResolveCopyCtors::postvisit( UniqueExpr * unqExpr ) {
                         if ( vars.count( unqExpr->get_id() ) ) {
@@ -529 +518 @@
                         } else {
                                 // expr isn't a call expr, so create a new temporary variable to use to hold the value of the unique expression
-                                unqExpr->set_object( ObjectDecl::newObject( toString("_unq", unqExpr->get_id()), unqExpr->get_result()->clone(), makeInit( unqExpr->get_result() ) ) );
+                                unqExpr->set_object( ObjectDecl::newObject( toString("_unq", unqExpr->get_id()), unqExpr->get_result()->clone(), nullptr ) );
                                 unqExpr->set_var( new VariableExpr( unqExpr->get_object() ) );
                         }
@@ -650 +639 @@
                 }
 
+                DeclarationWithType * getDtorFunc( ObjectDecl * objDecl, Statement * dtor, std::list< Statement * > & stmtsToAdd ) {
+                        if ( dynamic_cast< ExprStmt * >( dtor ) ) {
+                                if ( DeclarationWithType * func = getFunction( getCtorDtorCall( dtor ) ) ) {
+                                        // cleanup argument must be a function, not an object (including function pointer)
+                                        if ( FunctionDecl * dtorFunc = dynamic_cast< FunctionDecl * > ( func ) ) {
+                                                if ( dtorFunc->type->forall.empty() ) {
+                                                        // simple case where the destructor is a monomorphic function call - can simply
+                                                        // use that function as the cleanup function.
+                                                        delete dtor;
+                                                        return func;
+                                                }
+                                        }
+                                }
+                        }
+
+                        // otherwise the cleanup is more complicated - need to build a single argument cleanup function that
+                        // wraps the more complicated code.
+                        static UniqueName dtorNamer( "__cleanup_dtor" );
+                        FunctionDecl * dtorFunc = FunctionDecl::newFunction( dtorNamer.newName(), SymTab::genDefaultType( objDecl->type->stripReferences(), false ), new CompoundStmt( noLabels ) );
+                        stmtsToAdd.push_back( new DeclStmt( noLabels, dtorFunc ) );
+
+                        // the original code contains uses of objDecl - replace them with the newly generated 'this' parameter.
+                        ObjectDecl * thisParam = getParamThis( dtorFunc->type );
+                        VarExprReplacer::replace( dtor, { std::make_pair( objDecl, thisParam ) } );
+                        dtorFunc->statements->push_back( dtor );
+
+                        return dtorFunc;
+                }
+
                 DeclarationWithType * FixInit::postmutate( ObjectDecl *objDecl ) {
                         // since this removes the init field from objDecl, it must occur after children are mutated (i.e. postmutate)
@@ -762 +780 @@
                                                         ctorInit->ctor = nullptr;
                                                 }
+
+                                                Statement * dtor = ctorInit->dtor;
+                                                if ( dtor ) {
+                                                        ImplicitCtorDtorStmt * implicit = strict_dynamic_cast< ImplicitCtorDtorStmt * >( dtor );
+                                                        Statement * dtorStmt = implicit->callStmt;
+                                                        // don't need to call intrinsic dtor, because it does nothing, but
+                                                        // non-intrinsic dtors must be called
+                                                        if ( ! isIntrinsicSingleArgCallStmt( dtorStmt ) ) {
+                                                                // set dtor location to the object's location for error messages
+                                                                DeclarationWithType * dtorFunc = getDtorFunc( objDecl, dtorStmt, stmtsToAddBefore );
+                                                                objDecl->attributes.push_back( new Attribute( "cleanup", { new VariableExpr( dtorFunc ) } ) );
+                                                                // objDecl->attributes.push_back( new Attribute( "cleanup", { new NameExpr( dtorFunc->name ) } ) );
+                                                                ctorInit->dtor = nullptr;
+                                                        } // if
+                                                }
                                         } // if
                                 } else if ( Initializer * init = ctorInit->init ) {
@@ -804 +837 @@
 
 
-                template<typename Iterator, typename OutputIterator>
-                void insertDtors( Iterator begin, Iterator end, OutputIterator out ) {
-                        for ( Iterator it = begin ; it != end ; ++it ) {
-                                // extract destructor statement from the object decl and insert it into the output. Note that this is
-                                // only called on lists of non-static objects with implicit non-intrinsic dtors, so if the user manually
-                                // calls an intrinsic dtor then the call must (and will) still be generated since the argument may
-                                // contain side effects.
-                                ObjectDecl * objDecl = *it;
-                                ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() );
-                                assert( ctorInit && ctorInit->get_dtor() );
-                                *out++ = ctorInit->get_dtor()->clone();
-                        } // for
-                }
-
-                void InsertDtors::previsit( ObjectDecl * objDecl ) {
-                        // remember non-static destructed objects so that their destructors can be inserted later
-                        if ( ! objDecl->get_storageClasses().is_static ) {
-                                if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
-                                        // a decision should have been made by the resolver, so ctor and init are not both non-NULL
-                                        assert( ! ctorInit->get_ctor() || ! ctorInit->get_init() );
-                                        Statement * dtor = ctorInit->get_dtor();
-                                        // don't need to call intrinsic dtor, because it does nothing, but
-                                        // non-intrinsic dtors must be called
-                                        if ( dtor && ! isIntrinsicSingleArgCallStmt( dtor ) ) {
-                                                // set dtor location to the object's location for error messages
-                                                ctorInit->dtor->location = objDecl->location;
-                                                reverseDeclOrder.front().push_front( objDecl );
-                                        } // if
-                                } // if
-                        } // if
-                }
-
                 void InsertDtors::previsit( FunctionDecl * funcDecl ) {
                         // each function needs to have its own set of labels
@@ -848 +849 @@
                 }
 
-                void InsertDtors::previsit( CompoundStmt * compoundStmt ) {
-                        // visit statements - this will also populate reverseDeclOrder list.  don't want to dump all destructors
-                        // when block is left, just the destructors associated with variables defined in this block, so push a new
-                        // list to the top of the stack so that we can differentiate scopes
-                        reverseDeclOrder.push_front( OrderedDecls() );
-                        Parent::previsit( compoundStmt );
-                }
-
-                void InsertDtors::postvisit( CompoundStmt * compoundStmt ) {
-                        // add destructors for the current scope that we're exiting, unless the last statement is a return, which
-                        // causes unreachable code warnings
-                        std::list< Statement * > & statements = compoundStmt->get_kids();
-                        if ( ! statements.empty() && ! dynamic_cast< ReturnStmt * >( statements.back() ) ) {
-                                insertDtors( reverseDeclOrder.front().begin(), reverseDeclOrder.front().end(), back_inserter( statements ) );
-                        }
-                        reverseDeclOrder.pop_front();
-                }
-
-                void InsertDtors::previsit( ReturnStmt * ) {
-                        // return exits all scopes, so dump destructors for all scopes
-                        for ( OrderedDecls & od : reverseDeclOrder ) {
-                                insertDtors( od.begin(), od.end(), back_inserter( stmtsToAddBefore ) );
-                        } // for
-                }
-
                 // Handle break/continue/goto in the same manner as C++.  Basic idea: any objects that are in scope at the
                 // BranchStmt but not at the labelled (target) statement must be destructed.  If there are any objects in scope
@@ -900 +876 @@
                         if ( ! diff.empty() ) {
                                 throw SemanticError( std::string("jump to label '") + stmt->get_target().get_name() + "' crosses initialization of " + (*diff.begin())->get_name() + " ", stmt );
-                        } // if
-                        // S_G-S_L results in set of objects that must be destructed
-                        diff.clear();
-                        std::set_difference( curVars.begin(), curVars.end(), lvars.begin(), lvars.end(), std::inserter( diff, diff.end() ) );
-                        DTOR_PRINT(
-                                std::cerr << "S_G-S_L = " << printSet( diff ) << std::endl;
-                        )
-                        if ( ! diff.empty() ) {
-                                // create an auxilliary set for fast lookup -- can't make diff a set, because diff ordering should be consistent for error messages.
-                                std::unordered_set<ObjectDecl *> needsDestructor( diff.begin(), diff.end() );
-
-                                // go through decl ordered list of objectdecl. for each element that occurs in diff, output destructor
-                                OrderedDecls ordered;
-                                for ( OrderedDecls & rdo : reverseDeclOrder ) {
-                                        // add elements from reverseDeclOrder into ordered if they occur in diff - it is key that this happens in reverse declaration order.
-                                        copy_if( rdo.begin(), rdo.end(), back_inserter( ordered ), [&]( ObjectDecl * objDecl ) { return needsDestructor.count( objDecl ); } );
-                                } // for
-                                insertDtors( ordered.begin(), ordered.end(), back_inserter( stmtsToAddBefore ) );
                         } // if
                 }
@@ -956 +914 @@
                 }
 
+                void GenStructMemberCalls::previsit( StructDecl * structDecl ) {
+                        if ( ! dtorStruct && structDecl->name == "__Destructor" ) {
+                                dtorStruct = structDecl;
+                        }
+                }
+
                 void GenStructMemberCalls::previsit( FunctionDecl * funcDecl ) {
                         GuardValue( function );
@@ -968 +932 @@
                         unhandled.clear();
                         usedUninit.clear();
+
+                        if ( ! dtorStructDestroy && funcDecl->name == "__destroy_Destructor" ) {
+                                dtorStructDestroy = funcDecl;
+                                return;
+                        }
 
                         function = funcDecl;
@@ -979 +948 @@
                                 if ( structType ) {
                                         structDecl = structType->get_baseStruct();
+                                        if ( structDecl == dtorStruct ) return;
                                         for ( Declaration * member : structDecl->get_members() ) {
                                                 if ( ObjectDecl * field = dynamic_cast< ObjectDecl * >( member ) ) {
@@ -1050 +1020 @@
                                                         callStmt->acceptMutator( resolver );
                                                         if ( isCtor ) {
-                                                                function->get_statements()->push_front( callStmt );
+                                                                function->statements->push_front( callStmt );
                                                         } else {
                                                                 // destructor statements should be added at the end
-                                                                function->get_statements()->push_back( callStmt );
+                                                                // function->get_statements()->push_back( callStmt );
+
+                                                                // Destructor _dtor0 = { &b.a1, _destroy_A };
+                                                                std::list< Statement * > stmtsToAdd;
+
+                                                                static UniqueName memberDtorNamer = { "__memberDtor" };
+                                                                assertf( dtorStruct, "builtin __Destructor not found." );
+                                                                assertf( dtorStructDestroy, "builtin __destroy_Destructor not found." );
+
+                                                                Expression * thisExpr = new AddressExpr( new VariableExpr( thisParam ) );
+                                                                Expression * dtorExpr = new VariableExpr( getDtorFunc( thisParam, callStmt, stmtsToAdd ) );
+
+                                                                ObjectDecl * destructor = ObjectDecl::newObject( memberDtorNamer.newName(), new StructInstType( Type::Qualifiers(), dtorStruct ), new ListInit( { new SingleInit( thisExpr ), new SingleInit( dtorExpr ) } ) );
+                                                                function->statements->push_front( new DeclStmt( noLabels, destructor ) );
+                                                                destructor->attributes.push_back( new Attribute( "cleanup", { new VariableExpr( dtorStructDestroy ) } ) );
+
+                                                                function->statements->kids.splice( function->statements->kids.begin(), stmtsToAdd );
                                                         }
                                                 } catch ( SemanticError & error ) {