Index: src/InitTweak/FixInit.cc =================================================================== --- src/InitTweak/FixInit.cc (revision 1ba5803c90674cf77489dd4409a2afd3b782551e) +++ src/InitTweak/FixInit.cc (revision 9c3543102dd7ddc536fce11908c849a078505fc7) @@ -54,4 +54,5 @@ #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 @@ -158,10 +159,6 @@ 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: @@ -203,4 +200,6 @@ static void generate( std::list< Declaration * > & translationUnit ); + void previsit( StructDecl * structDecl ); + void previsit( FunctionDecl * funcDecl ); void postvisit( FunctionDecl * funcDecl ); @@ -220,4 +219,8 @@ 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; }; @@ -644,4 +647,55 @@ } + DeclarationWithType * getDtorFunc( ObjectDecl * objDecl, Statement * input, std::list< Statement * > & stmtsToAdd ) { + // unwrap implicit statement wrapper + Statement * dtor = input; + if ( ImplicitCtorDtorStmt * implicit = dynamic_cast< ImplicitCtorDtorStmt * >( input ) ) { + // dtor = implicit->callStmt; + // implicit->callStmt = nullptr; + } + assert( dtor ); + std::list< Expression * > matches; + collectCtorDtorCalls( dtor, matches ); + + if ( dynamic_cast< ExprStmt * >( dtor ) ) { + // only one destructor call in the expression + if ( matches.size() == 1 ) { + DeclarationWithType * func = getFunction( matches.front() ); + assertf( func, "getFunction failed to find function in %s", toString( matches.front() ).c_str() ); + + // 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 ); + Expression * replacement = new VariableExpr( thisParam ); + + Type * base = replacement->result->stripReferences(); + if ( dynamic_cast< ArrayType * >( base ) || dynamic_cast< TupleType * > ( base ) ) { + // need to cast away reference for array types, since the destructor is generated without the reference type, + // and for tuple types since tuple indexing does not work directly on a reference + replacement = new CastExpr( replacement, base->clone() ); + } + VarExprReplacer::replace( dtor, { std::make_pair( objDecl, replacement ) } ); + 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) @@ -756,4 +810,19 @@ 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 ) } ) ); + ctorInit->dtor = nullptr; + } // if + } } // if } else if ( Initializer * init = ctorInit->init ) { @@ -798,36 +867,4 @@ - template - 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 @@ -842,29 +879,4 @@ } - 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 @@ -894,22 +906,4 @@ 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 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 } @@ -937,4 +931,10 @@ } + void GenStructMemberCalls::previsit( StructDecl * structDecl ) { + if ( ! dtorStruct && structDecl->name == "__Destructor" ) { + dtorStruct = structDecl; + } + } + void GenStructMemberCalls::previsit( FunctionDecl * funcDecl ) { GuardValue( function ); @@ -949,4 +949,9 @@ unhandled.clear(); usedUninit.clear(); + + if ( ! dtorStructDestroy && funcDecl->name == "__destroy_Destructor" ) { + dtorStructDestroy = funcDecl; + return; + } function = funcDecl; @@ -960,4 +965,5 @@ if ( structType ) { structDecl = structType->get_baseStruct(); + if ( structDecl == dtorStruct ) return; for ( Declaration * member : structDecl->get_members() ) { if ( ObjectDecl * field = dynamic_cast< ObjectDecl * >( member ) ) { @@ -1029,8 +1035,29 @@ 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, (void (*)(void *)_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 ) ); + + // cast destructor pointer to void (*)(void *), to silence GCC incompatible pointer warnings + FunctionType * dtorFtype = new FunctionType( Type::Qualifiers(), false ); + dtorFtype->parameters.push_back( ObjectDecl::newObject( "", new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), nullptr ) ); + Type * dtorType = new PointerType( Type::Qualifiers(), dtorFtype ); + + ObjectDecl * destructor = ObjectDecl::newObject( memberDtorNamer.newName(), new StructInstType( Type::Qualifiers(), dtorStruct ), new ListInit( { new SingleInit( thisExpr ), new SingleInit( new CastExpr( dtorExpr, dtorType ) ) } ) ); + 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 ) { Index: src/InitTweak/InitTweak.cc =================================================================== --- src/InitTweak/InitTweak.cc (revision 1ba5803c90674cf77489dd4409a2afd3b782551e) +++ src/InitTweak/InitTweak.cc (revision 9c3543102dd7ddc536fce11908c849a078505fc7) @@ -345,5 +345,5 @@ std::list< Expression * > matches; collectCtorDtorCalls( stmt, matches ); - assert( matches.size() <= 1 ); + assertf( matches.size() <= 1, "%zd constructor/destructors found in %s", matches.size(), toString( stmt ).c_str() ); return matches.size() == 1 ? matches.front() : nullptr; }