| 1 | //
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
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| 3 | //
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| 4 | // The contents of this file are covered under the licence agreement in the
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| 5 | // file "LICENCE" distributed with Cforall.
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| 6 | //
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| 7 | // ExceptVisitor.cc --
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| 8 | //
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| 9 | // Author           : Andrew Beach
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| 10 | // Created On       : Wed Jun 14 16:49:00 2017
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| 11 | // Last Modified By : Andrew Beach
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| 12 | // Last Modified On : Wed Jun 24 11:18:00 2020
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| 13 | // Update Count     : 17
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| 14 | //
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| 15 | 
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| 16 | #include "ExceptTranslate.h"
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| 17 | 
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| 18 | #include <stddef.h>                   // for NULL
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| 19 | #include <cassert>                    // for assert, assertf
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| 20 | #include <iterator>                   // for back_inserter, inserter
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| 21 | #include <string>                     // for string, operator==
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| 22 | 
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| 23 | #include "Common/PassVisitor.h"       // for PassVisitor, WithGuards
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| 24 | #include "Common/SemanticError.h"     // for SemanticError
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| 25 | #include "Common/utility.h"           // for CodeLocation
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| 26 | #include "SynTree/LinkageSpec.h"      // for Cforall
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| 27 | #include "SynTree/Attribute.h"        // for Attribute
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| 28 | #include "SynTree/Constant.h"         // for Constant
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| 29 | #include "SynTree/Declaration.h"      // for ObjectDecl, FunctionDecl, Struc...
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| 30 | #include "SynTree/Expression.h"       // for UntypedExpr, ConstantExpr, Name...
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| 31 | #include "SynTree/Initializer.h"      // for SingleInit, ListInit
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| 32 | #include "SynTree/Label.h"            // for Label
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| 33 | #include "SynTree/Mutator.h"          // for mutateAll
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| 34 | #include "SynTree/Statement.h"        // for CompoundStmt, CatchStmt, ThrowStmt
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| 35 | #include "SynTree/Type.h"             // for FunctionType, Type, noQualifiers
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| 36 | #include "SynTree/DeclReplacer.h"     // for DeclReplacer
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| 37 | #include "SynTree/Visitor.h"          // for acceptAll
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| 38 | 
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| 39 | namespace ControlStruct {
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| 40 | 
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| 41 |         // Buricratic Helpers (Not having to do with the paritular operation.)
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| 42 | 
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| 43 |         typedef std::list<CatchStmt*> CatchList;
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| 44 | 
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| 45 |         void split( CatchList& allHandlers, CatchList& terHandlers,
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| 46 |                                 CatchList& resHandlers ) {
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| 47 |                 while ( !allHandlers.empty() ) {
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| 48 |                         CatchStmt * stmt = allHandlers.front();
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| 49 |                         allHandlers.pop_front();
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| 50 |                         if (CatchStmt::Terminate == stmt->get_kind()) {
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| 51 |                                 terHandlers.push_back(stmt);
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| 52 |                         } else {
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| 53 |                                 resHandlers.push_back(stmt);
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| 54 |                         }
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| 55 |                 }
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| 56 |         }
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| 57 | 
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| 58 |         void appendDeclStmt( CompoundStmt * block, Declaration * item ) {
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| 59 |                 block->push_back(new DeclStmt(item));
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| 60 |         }
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| 61 | 
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| 62 |         Expression * nameOf( DeclarationWithType * decl ) {
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| 63 |                 return new VariableExpr( decl );
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| 64 |         }
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| 65 | 
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| 66 |         class ThrowMutatorCore : public WithGuards {
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| 67 |                 ObjectDecl * terminate_handler_except;
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| 68 |                 enum Context { NoHandler, TerHandler, ResHandler } cur_context;
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| 69 | 
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| 70 |                 // The helper functions for code/syntree generation.
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| 71 |                 Statement * create_either_throw(
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| 72 |                         ThrowStmt * throwStmt, const char * throwFunc );
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| 73 |                 Statement * create_terminate_rethrow( ThrowStmt * throwStmt );
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| 74 | 
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| 75 |         public:
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| 76 |                 ThrowMutatorCore() :
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| 77 |                         terminate_handler_except( nullptr ),
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| 78 |                         cur_context( NoHandler )
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| 79 |                 {}
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| 80 | 
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| 81 |                 void premutate( CatchStmt *catchStmt );
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| 82 |                 Statement * postmutate( ThrowStmt *throwStmt );
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| 83 |         };
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| 84 | 
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| 85 |         // ThrowStmt Mutation Helpers
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| 86 | 
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| 87 |         Statement * ThrowMutatorCore::create_either_throw(
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| 88 |                         ThrowStmt * throwStmt, const char * throwFunc ) {
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| 89 |                 // `throwFunc`( `throwStmt->get_name()` );
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| 90 |                 UntypedExpr * call = new UntypedExpr( new NameExpr( throwFunc ) );
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| 91 |                 call->get_args().push_back( throwStmt->get_expr() );
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| 92 |                 throwStmt->set_expr( nullptr );
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| 93 |                 delete throwStmt;
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| 94 |                 return new ExprStmt( call );
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| 95 |         }
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| 96 | 
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| 97 |         Statement * ThrowMutatorCore::create_terminate_rethrow(
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| 98 |                         ThrowStmt *throwStmt ) {
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| 99 |                 // { `terminate_handler_except` = 0p; __rethrow_terminate(); }
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| 100 |                 assert( nullptr == throwStmt->get_expr() );
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| 101 |                 assert( terminate_handler_except );
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| 102 | 
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| 103 |                 CompoundStmt * result = new CompoundStmt();
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| 104 |                 result->labels =  throwStmt->labels;
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| 105 |                 result->push_back( new ExprStmt( UntypedExpr::createAssign(
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| 106 |                         nameOf( terminate_handler_except ),
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| 107 |                         new ConstantExpr( Constant::null(
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| 108 |                                 terminate_handler_except->get_type()->clone()
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| 109 |                                 ) )
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| 110 |                         ) ) );
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| 111 |                 result->push_back( new ExprStmt(
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| 112 |                         new UntypedExpr( new NameExpr( "__cfaehm_rethrow_terminate" ) )
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| 113 |                         ) );
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| 114 |                 delete throwStmt;
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| 115 |                 return result;
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| 116 |         }
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| 117 | 
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| 118 |         // Visiting/Mutating Functions
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| 119 | 
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| 120 |         void ThrowMutatorCore::premutate( CatchStmt *catchStmt ) {
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| 121 |                 // Validate the statement's form.
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| 122 |                 ObjectDecl * decl = dynamic_cast<ObjectDecl *>( catchStmt->get_decl() );
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| 123 |                 // Also checking the type would be nice.
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| 124 |                 if ( !decl || !dynamic_cast<PointerType *>( decl->type ) ) {
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| 125 |                         std::string kind = (CatchStmt::Terminate == catchStmt->kind) ? "catch" : "catchResume";
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| 126 |                         SemanticError( catchStmt->location, kind + " must have pointer to an exception type" );
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| 127 |                 }
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| 128 | 
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| 129 |                 // Track the handler context.
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| 130 |                 GuardValue( cur_context );
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| 131 |                 if ( CatchStmt::Terminate == catchStmt->get_kind() ) {
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| 132 |                         cur_context = TerHandler;
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| 133 | 
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| 134 |                         GuardValue( terminate_handler_except );
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| 135 |                         terminate_handler_except = decl;
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| 136 |                 } else {
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| 137 |                         cur_context = ResHandler;
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| 138 |                 }
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| 139 |         }
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| 140 | 
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| 141 |         Statement * ThrowMutatorCore::postmutate( ThrowStmt *throwStmt ) {
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| 142 |                 // Ignoring throwStmt->get_target() for now.
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| 143 |                 if ( ThrowStmt::Terminate == throwStmt->get_kind() ) {
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| 144 |                         if ( throwStmt->get_expr() ) {
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| 145 |                                 return create_either_throw( throwStmt, "$throw" );
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| 146 |                         } else if ( TerHandler == cur_context ) {
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| 147 |                                 return create_terminate_rethrow( throwStmt );
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| 148 |                         } else {
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| 149 |                                 abort("Invalid throw in %s at %i\n",
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| 150 |                                         throwStmt->location.filename.c_str(),
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| 151 |                                         throwStmt->location.first_line);
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| 152 |                         }
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| 153 |                 } else {
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| 154 |                         if ( throwStmt->get_expr() ) {
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| 155 |                                 return create_either_throw( throwStmt, "$throwResume" );
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| 156 |                         } else if ( ResHandler == cur_context ) {
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| 157 |                                 // This has to be handled later.
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| 158 |                                 return throwStmt;
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| 159 |                         } else {
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| 160 |                                 abort("Invalid throwResume in %s at %i\n",
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| 161 |                                         throwStmt->location.filename.c_str(),
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| 162 |                                         throwStmt->location.first_line);
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| 163 |                         }
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| 164 |                 }
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| 165 |         }
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| 166 | 
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| 167 |         class TryMutatorCore {
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| 168 |                 // The built in types used in translation.
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| 169 |                 StructDecl * except_decl;
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| 170 |                 StructDecl * node_decl;
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| 171 |                 StructDecl * hook_decl;
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| 172 | 
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| 173 |                 // The many helper functions for code/syntree generation.
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| 174 |                 CompoundStmt * take_try_block( TryStmt * tryStmt );
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| 175 |                 FunctionDecl * create_try_wrapper( CompoundStmt * body );
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| 176 |                 FunctionDecl * create_terminate_catch( CatchList &handlers );
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| 177 |                 CompoundStmt * create_single_matcher(
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| 178 |                         DeclarationWithType * except_obj, CatchStmt * modded_handler );
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| 179 |                 FunctionDecl * create_terminate_match( CatchList &handlers );
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| 180 |                 CompoundStmt * create_terminate_caller( FunctionDecl * try_wrapper,
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| 181 |                         FunctionDecl * terminate_catch, FunctionDecl * terminate_match );
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| 182 |                 FunctionDecl * create_resume_handler( CatchList &handlers );
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| 183 |                 CompoundStmt * create_resume_wrapper(
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| 184 |                         Statement * wraps, FunctionDecl * resume_handler );
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| 185 |                 FunctionDecl * create_finally_wrapper( TryStmt * tryStmt );
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| 186 |                 ObjectDecl * create_finally_hook( FunctionDecl * finally_wrapper );
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| 187 |                 Statement * create_resume_rethrow( ThrowStmt * throwStmt );
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| 188 | 
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| 189 |                 // Types used in translation, make sure to use clone.
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| 190 |                 // void (*function)();
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| 191 |                 FunctionType try_func_t;
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| 192 |                 // void (*function)(int, exception);
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| 193 |                 FunctionType catch_func_t;
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| 194 |                 // int (*function)(exception);
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| 195 |                 FunctionType match_func_t;
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| 196 |                 // bool (*function)(exception);
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| 197 |                 FunctionType handle_func_t;
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| 198 |                 // void (*function)(__attribute__((unused)) void *);
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| 199 |                 FunctionType finally_func_t;
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| 200 | 
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| 201 |                 StructInstType * create_except_type() {
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| 202 |                         assert( except_decl );
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| 203 |                         return new StructInstType( noQualifiers, except_decl );
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| 204 |                 }
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| 205 |                 void init_func_types();
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| 206 | 
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| 207 |         public:
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| 208 |                 TryMutatorCore() :
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| 209 |                         except_decl( nullptr ), node_decl( nullptr ), hook_decl( nullptr ),
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| 210 |                         try_func_t( noQualifiers, false ),
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| 211 |                         catch_func_t( noQualifiers, false ),
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| 212 |                         match_func_t( noQualifiers, false ),
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| 213 |                         handle_func_t( noQualifiers, false ),
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| 214 |                         finally_func_t( noQualifiers, false )
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| 215 |                 {}
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| 216 | 
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| 217 |                 void premutate( StructDecl *structDecl );
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| 218 |                 Statement * postmutate( TryStmt *tryStmt );
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| 219 |                 Statement * postmutate( ThrowStmt *throwStmt );
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| 220 |         };
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| 221 | 
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| 222 |         void TryMutatorCore::init_func_types() {
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| 223 |                 assert( except_decl );
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| 224 | 
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| 225 |                 ObjectDecl index_obj(
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| 226 |                         "__handler_index",
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| 227 |                         Type::StorageClasses(),
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| 228 |                         LinkageSpec::Cforall,
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| 229 |                         /*bitfieldWidth*/ NULL,
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| 230 |                         new BasicType( noQualifiers, BasicType::SignedInt ),
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| 231 |                         /*init*/ NULL
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| 232 |                         );
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| 233 |                 ObjectDecl exception_obj(
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| 234 |                         "__exception_inst",
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| 235 |                         Type::StorageClasses(),
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| 236 |                         LinkageSpec::Cforall,
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| 237 |                         /*bitfieldWidth*/ NULL,
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| 238 |                         new PointerType(
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| 239 |                                 noQualifiers,
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| 240 |                                 new StructInstType( noQualifiers, except_decl )
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| 241 |                                 ),
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| 242 |                         /*init*/ NULL
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| 243 |                         );
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| 244 |                 ObjectDecl bool_obj(
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| 245 |                         "__ret_bool",
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| 246 |                         Type::StorageClasses(),
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| 247 |                         LinkageSpec::Cforall,
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| 248 |                         /*bitfieldWidth*/ NULL,
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| 249 |                         new BasicType( noQualifiers, BasicType::Bool ),
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| 250 |                         /*init*/ NULL,
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| 251 |                         std::list<Attribute *>{ new Attribute( "unused" ) }
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| 252 |                         );
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| 253 |                 ObjectDecl voidptr_obj(
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| 254 |                         "__hook",
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| 255 |                         Type::StorageClasses(),
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| 256 |                         LinkageSpec::Cforall,
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| 257 |                         NULL,
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| 258 |                         new PointerType(
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| 259 |                                 noQualifiers,
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| 260 |                                 new VoidType(
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| 261 |                                         noQualifiers
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| 262 |                                         ),
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| 263 |                                 std::list<Attribute *>{ new Attribute( "unused" ) }
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| 264 |                                 ),
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| 265 |                         NULL
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| 266 |                         );
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| 267 | 
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| 268 |                 ObjectDecl * unused_index_obj = index_obj.clone();
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| 269 |                 unused_index_obj->attributes.push_back( new Attribute( "unused" ) );
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| 270 | 
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| 271 |                 catch_func_t.get_parameters().push_back( index_obj.clone() );
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| 272 |                 catch_func_t.get_parameters().push_back( exception_obj.clone() );
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| 273 |                 match_func_t.get_returnVals().push_back( unused_index_obj );
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| 274 |                 match_func_t.get_parameters().push_back( exception_obj.clone() );
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| 275 |                 handle_func_t.get_returnVals().push_back( bool_obj.clone() );
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| 276 |                 handle_func_t.get_parameters().push_back( exception_obj.clone() );
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| 277 |                 finally_func_t.get_parameters().push_back( voidptr_obj.clone() );
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| 278 |         }
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| 279 | 
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| 280 |         // TryStmt Mutation Helpers
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| 281 | 
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| 282 |         CompoundStmt * TryMutatorCore::take_try_block( TryStmt *tryStmt ) {
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| 283 |                 CompoundStmt * block = tryStmt->get_block();
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| 284 |                 tryStmt->set_block( nullptr );
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| 285 |                 return block;
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| 286 |         }
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| 287 | 
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| 288 |         FunctionDecl * TryMutatorCore::create_try_wrapper(
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| 289 |                         CompoundStmt *body ) {
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| 290 | 
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| 291 |                 return new FunctionDecl( "try", Type::StorageClasses(),
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| 292 |                         LinkageSpec::Cforall, try_func_t.clone(), body );
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| 293 |         }
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| 294 | 
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| 295 |         FunctionDecl * TryMutatorCore::create_terminate_catch(
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| 296 |                         CatchList &handlers ) {
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| 297 |                 std::list<CaseStmt *> handler_wrappers;
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| 298 | 
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| 299 |                 FunctionType *func_type = catch_func_t.clone();
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| 300 |                 DeclarationWithType * index_obj = func_type->get_parameters().front();
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| 301 |                 DeclarationWithType * except_obj = func_type->get_parameters().back();
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| 302 | 
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| 303 |                 // Index 1..{number of handlers}
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| 304 |                 int index = 0;
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| 305 |                 CatchList::iterator it = handlers.begin();
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| 306 |                 for ( ; it != handlers.end() ; ++it ) {
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| 307 |                         ++index;
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| 308 |                         CatchStmt * handler = *it;
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| 309 | 
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| 310 |                         // case `index`:
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| 311 |                         // {
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| 312 |                         //     `handler.decl` = { (virtual `decl.type`)`except` };
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| 313 |                         //     `handler.body`;
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| 314 |                         // }
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| 315 |                         // return;
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| 316 |                         CompoundStmt * block = new CompoundStmt();
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| 317 | 
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| 318 |                         // Just copy the exception value. (Post Validation)
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| 319 |                         ObjectDecl * handler_decl =
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| 320 |                                 static_cast<ObjectDecl *>( handler->get_decl() );
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| 321 |                         ObjectDecl * local_except = handler_decl->clone();
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| 322 |                         local_except->set_init(
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| 323 |                                 new ListInit({ new SingleInit(
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| 324 |                                         new VirtualCastExpr( nameOf( except_obj ),
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| 325 |                                                 local_except->get_type()
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| 326 |                                                 )
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| 327 |                                         ) })
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| 328 |                                 );
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| 329 |                         block->push_back( new DeclStmt( local_except ) );
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| 330 | 
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| 331 |                         // Add the cleanup attribute.
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| 332 |                         local_except->get_attributes().push_back( new Attribute(
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| 333 |                                 "cleanup",
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| 334 |                                 { new NameExpr( "__cfaehm_cleanup_terminate" ) }
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| 335 |                                 ) );
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| 336 | 
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| 337 |                         // Update variables in the body to point to this local copy.
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| 338 |                         {
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| 339 |                                 DeclReplacer::DeclMap mapping;
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| 340 |                                 mapping[ handler_decl ] = local_except;
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| 341 |                                 DeclReplacer::replace( handler->body, mapping );
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| 342 |                         }
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| 343 | 
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| 344 |                         block->push_back( handler->body );
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| 345 |                         handler->body = nullptr;
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| 346 | 
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| 347 |                         std::list<Statement *> caseBody
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| 348 |                                         { block, new ReturnStmt( nullptr ) };
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| 349 |                         handler_wrappers.push_back( new CaseStmt(
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| 350 |                                 new ConstantExpr( Constant::from_int( index ) ),
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| 351 |                                 caseBody
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| 352 |                                 ) );
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| 353 |                 }
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| 354 |                 // TODO: Some sort of meaningful error on default perhaps?
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| 355 | 
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| 356 |                 std::list<Statement*> stmt_handlers;
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| 357 |                 while ( !handler_wrappers.empty() ) {
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| 358 |                         stmt_handlers.push_back( handler_wrappers.front() );
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| 359 |                         handler_wrappers.pop_front();
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| 360 |                 }
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| 361 | 
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| 362 |                 SwitchStmt * handler_lookup = new SwitchStmt(
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| 363 |                         nameOf( index_obj ),
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| 364 |                         stmt_handlers
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| 365 |                         );
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| 366 |                 CompoundStmt * body = new CompoundStmt();
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| 367 |                 body->push_back( handler_lookup );
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| 368 | 
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| 369 |                 return new FunctionDecl("catch", Type::StorageClasses(),
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| 370 |                         LinkageSpec::Cforall, func_type, body);
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| 371 |         }
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| 372 | 
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| 373 |         // Create a single check from a moddified handler.
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| 374 |         // except_obj is referenced, modded_handler will be freed.
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| 375 |         CompoundStmt * TryMutatorCore::create_single_matcher(
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| 376 |                         DeclarationWithType * except_obj, CatchStmt * modded_handler ) {
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| 377 |                 // {
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| 378 |                 //     `modded_handler.decl`
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| 379 |                 //     if ( `decl.name = (virtual `decl.type`)`except`
 | 
|---|
| 380 |                 //             [&& `modded_handler.cond`] ) {
 | 
|---|
| 381 |                 //         `modded_handler.body`
 | 
|---|
| 382 |                 //     }
 | 
|---|
| 383 |                 // }
 | 
|---|
| 384 | 
 | 
|---|
| 385 |                 CompoundStmt * block = new CompoundStmt();
 | 
|---|
| 386 | 
 | 
|---|
| 387 |                 // Local Declaration
 | 
|---|
| 388 |                 ObjectDecl * local_except =
 | 
|---|
| 389 |                         dynamic_cast<ObjectDecl *>( modded_handler->get_decl() );
 | 
|---|
| 390 |                 assert( local_except );
 | 
|---|
| 391 |                 block->push_back( new DeclStmt( local_except ) );
 | 
|---|
| 392 | 
 | 
|---|
| 393 |                 // Check for type match.
 | 
|---|
| 394 |                 Expression * cond = UntypedExpr::createAssign( nameOf( local_except ),
 | 
|---|
| 395 |                         new VirtualCastExpr( nameOf( except_obj ),
 | 
|---|
| 396 |                                 local_except->get_type()->clone() ) );
 | 
|---|
| 397 | 
 | 
|---|
| 398 |                 // Add the check on the conditional if it is provided.
 | 
|---|
| 399 |                 if ( modded_handler->get_cond() ) {
 | 
|---|
| 400 |                         cond = new LogicalExpr( cond, modded_handler->get_cond() );
 | 
|---|
| 401 |                 }
 | 
|---|
| 402 |                 // Construct the match condition.
 | 
|---|
| 403 |                 block->push_back( new IfStmt(
 | 
|---|
| 404 |                         cond, modded_handler->get_body(), nullptr ) );
 | 
|---|
| 405 | 
 | 
|---|
| 406 |                 modded_handler->set_decl( nullptr );
 | 
|---|
| 407 |                 modded_handler->set_cond( nullptr );
 | 
|---|
| 408 |                 modded_handler->set_body( nullptr );
 | 
|---|
| 409 |                 delete modded_handler;
 | 
|---|
| 410 |                 return block;
 | 
|---|
| 411 |         }
 | 
|---|
| 412 | 
 | 
|---|
| 413 |         FunctionDecl * TryMutatorCore::create_terminate_match(
 | 
|---|
| 414 |                         CatchList &handlers ) {
 | 
|---|
| 415 |                 // int match(exception * except) {
 | 
|---|
| 416 |                 //     HANDLER WRAPPERS { return `index`; }
 | 
|---|
| 417 |                 // }
 | 
|---|
| 418 | 
 | 
|---|
| 419 |                 CompoundStmt * body = new CompoundStmt();
 | 
|---|
| 420 | 
 | 
|---|
| 421 |                 FunctionType * func_type = match_func_t.clone();
 | 
|---|
| 422 |                 DeclarationWithType * except_obj = func_type->get_parameters().back();
 | 
|---|
| 423 | 
 | 
|---|
| 424 |                 // Index 1..{number of handlers}
 | 
|---|
| 425 |                 int index = 0;
 | 
|---|
| 426 |                 CatchList::iterator it;
 | 
|---|
| 427 |                 for ( it = handlers.begin() ; it != handlers.end() ; ++it ) {
 | 
|---|
| 428 |                         ++index;
 | 
|---|
| 429 |                         CatchStmt * handler = *it;
 | 
|---|
| 430 | 
 | 
|---|
| 431 |                         // Body should have been taken by create_terminate_catch.
 | 
|---|
| 432 |                         assert( nullptr == handler->get_body() );
 | 
|---|
| 433 | 
 | 
|---|
| 434 |                         // Create new body.
 | 
|---|
| 435 |                         handler->set_body( new ReturnStmt(
 | 
|---|
| 436 |                                 new ConstantExpr( Constant::from_int( index ) ) ) );
 | 
|---|
| 437 | 
 | 
|---|
| 438 |                         // Create the handler.
 | 
|---|
| 439 |                         body->push_back( create_single_matcher( except_obj, handler ) );
 | 
|---|
| 440 |                         *it = nullptr;
 | 
|---|
| 441 |                 }
 | 
|---|
| 442 | 
 | 
|---|
| 443 |                 body->push_back( new ReturnStmt(
 | 
|---|
| 444 |                         new ConstantExpr( Constant::from_int( 0 ) ) ) );
 | 
|---|
| 445 | 
 | 
|---|
| 446 |                 return new FunctionDecl("match", Type::StorageClasses(),
 | 
|---|
| 447 |                         LinkageSpec::Cforall, func_type, body);
 | 
|---|
| 448 |         }
 | 
|---|
| 449 | 
 | 
|---|
| 450 |         CompoundStmt * TryMutatorCore::create_terminate_caller(
 | 
|---|
| 451 |                         FunctionDecl * try_wrapper,
 | 
|---|
| 452 |                         FunctionDecl * terminate_catch,
 | 
|---|
| 453 |                         FunctionDecl * terminate_match ) {
 | 
|---|
| 454 |                 // { __cfaehm_try_terminate(`try`, `catch`, `match`); }
 | 
|---|
| 455 | 
 | 
|---|
| 456 |                 UntypedExpr * caller = new UntypedExpr( new NameExpr(
 | 
|---|
| 457 |                         "__cfaehm_try_terminate" ) );
 | 
|---|
| 458 |                 std::list<Expression *>& args = caller->get_args();
 | 
|---|
| 459 |                 args.push_back( nameOf( try_wrapper ) );
 | 
|---|
| 460 |                 args.push_back( nameOf( terminate_catch ) );
 | 
|---|
| 461 |                 args.push_back( nameOf( terminate_match ) );
 | 
|---|
| 462 | 
 | 
|---|
| 463 |                 CompoundStmt * callStmt = new CompoundStmt();
 | 
|---|
| 464 |                 callStmt->push_back( new ExprStmt( caller ) );
 | 
|---|
| 465 |                 return callStmt;
 | 
|---|
| 466 |         }
 | 
|---|
| 467 | 
 | 
|---|
| 468 |         FunctionDecl * TryMutatorCore::create_resume_handler(
 | 
|---|
| 469 |                         CatchList &handlers ) {
 | 
|---|
| 470 |                 // bool handle(exception * except) {
 | 
|---|
| 471 |                 //     HANDLER WRAPPERS { `hander->body`; return true; }
 | 
|---|
| 472 |                 // }
 | 
|---|
| 473 |                 CompoundStmt * body = new CompoundStmt();
 | 
|---|
| 474 | 
 | 
|---|
| 475 |                 FunctionType * func_type = handle_func_t.clone();
 | 
|---|
| 476 |                 DeclarationWithType * except_obj = func_type->get_parameters().back();
 | 
|---|
| 477 | 
 | 
|---|
| 478 |                 CatchList::iterator it;
 | 
|---|
| 479 |                 for ( it = handlers.begin() ; it != handlers.end() ; ++it ) {
 | 
|---|
| 480 |                         CatchStmt * handler = *it;
 | 
|---|
| 481 | 
 | 
|---|
| 482 |                         // Modifiy body.
 | 
|---|
| 483 |                         CompoundStmt * handling_code =
 | 
|---|
| 484 |                                 dynamic_cast<CompoundStmt*>( handler->get_body() );
 | 
|---|
| 485 |                         if ( ! handling_code ) {
 | 
|---|
| 486 |                                 handling_code = new CompoundStmt();
 | 
|---|
| 487 |                                 handling_code->push_back( handler->get_body() );
 | 
|---|
| 488 |                         }
 | 
|---|
| 489 |                         handling_code->push_back( new ReturnStmt(
 | 
|---|
| 490 |                                 new ConstantExpr( Constant::from_bool( true ) ) ) );
 | 
|---|
| 491 |                         handler->set_body( handling_code );
 | 
|---|
| 492 | 
 | 
|---|
| 493 |                         // Create the handler.
 | 
|---|
| 494 |                         body->push_back( create_single_matcher( except_obj, handler ) );
 | 
|---|
| 495 |                         *it = nullptr;
 | 
|---|
| 496 |                 }
 | 
|---|
| 497 | 
 | 
|---|
| 498 |                 body->push_back( new ReturnStmt(
 | 
|---|
| 499 |                         new ConstantExpr( Constant::from_bool( false ) ) ) );
 | 
|---|
| 500 | 
 | 
|---|
| 501 |                 return new FunctionDecl("handle", Type::StorageClasses(),
 | 
|---|
| 502 |                         LinkageSpec::Cforall, func_type, body);
 | 
|---|
| 503 |         }
 | 
|---|
| 504 | 
 | 
|---|
| 505 |         CompoundStmt * TryMutatorCore::create_resume_wrapper(
 | 
|---|
| 506 |                         Statement * wraps,
 | 
|---|
| 507 |                         FunctionDecl * resume_handler ) {
 | 
|---|
| 508 |                 CompoundStmt * body = new CompoundStmt();
 | 
|---|
| 509 | 
 | 
|---|
| 510 |                 // struct __try_resume_node __resume_node
 | 
|---|
| 511 |                 //      __attribute__((cleanup( __cfaehm_try_resume_cleanup )));
 | 
|---|
| 512 |                 // ** unwinding of the stack here could cause problems **
 | 
|---|
| 513 |                 // ** however I don't think that can happen currently **
 | 
|---|
| 514 |                 // __cfaehm_try_resume_setup( &__resume_node, resume_handler );
 | 
|---|
| 515 | 
 | 
|---|
| 516 |                 std::list< Attribute * > attributes;
 | 
|---|
| 517 |                 {
 | 
|---|
| 518 |                         std::list< Expression * > attr_params;
 | 
|---|
| 519 |                         attr_params.push_back( new NameExpr(
 | 
|---|
| 520 |                                 "__cfaehm_try_resume_cleanup" ) );
 | 
|---|
| 521 |                         attributes.push_back( new Attribute( "cleanup", attr_params ) );
 | 
|---|
| 522 |                 }
 | 
|---|
| 523 | 
 | 
|---|
| 524 |                 ObjectDecl * obj = new ObjectDecl(
 | 
|---|
| 525 |                         "__resume_node",
 | 
|---|
| 526 |                         Type::StorageClasses(),
 | 
|---|
| 527 |                         LinkageSpec::Cforall,
 | 
|---|
| 528 |                         nullptr,
 | 
|---|
| 529 |                         new StructInstType(
 | 
|---|
| 530 |                                 Type::Qualifiers(),
 | 
|---|
| 531 |                                 node_decl
 | 
|---|
| 532 |                                 ),
 | 
|---|
| 533 |                         nullptr,
 | 
|---|
| 534 |                         attributes
 | 
|---|
| 535 |                         );
 | 
|---|
| 536 |                 appendDeclStmt( body, obj );
 | 
|---|
| 537 | 
 | 
|---|
| 538 |                 UntypedExpr *setup = new UntypedExpr( new NameExpr(
 | 
|---|
| 539 |                         "__cfaehm_try_resume_setup" ) );
 | 
|---|
| 540 |                 setup->get_args().push_back( new AddressExpr( nameOf( obj ) ) );
 | 
|---|
| 541 |                 setup->get_args().push_back( nameOf( resume_handler ) );
 | 
|---|
| 542 | 
 | 
|---|
| 543 |                 body->push_back( new ExprStmt( setup ) );
 | 
|---|
| 544 | 
 | 
|---|
| 545 |                 body->push_back( wraps );
 | 
|---|
| 546 |                 return body;
 | 
|---|
| 547 |         }
 | 
|---|
| 548 | 
 | 
|---|
| 549 |         FunctionDecl * TryMutatorCore::create_finally_wrapper(
 | 
|---|
| 550 |                         TryStmt * tryStmt ) {
 | 
|---|
| 551 |                 // void finally() { `finally->block` }
 | 
|---|
| 552 |                 FinallyStmt * finally = tryStmt->get_finally();
 | 
|---|
| 553 |                 CompoundStmt * body = finally->get_block();
 | 
|---|
| 554 |                 finally->set_block( nullptr );
 | 
|---|
| 555 |                 delete finally;
 | 
|---|
| 556 |                 tryStmt->set_finally( nullptr );
 | 
|---|
| 557 | 
 | 
|---|
| 558 |                 return new FunctionDecl("finally", Type::StorageClasses(),
 | 
|---|
| 559 |                         LinkageSpec::Cforall, finally_func_t.clone(), body);
 | 
|---|
| 560 |         }
 | 
|---|
| 561 | 
 | 
|---|
| 562 |         ObjectDecl * TryMutatorCore::create_finally_hook(
 | 
|---|
| 563 |                         FunctionDecl * finally_wrapper ) {
 | 
|---|
| 564 |                 // struct __cfaehm_cleanup_hook __finally_hook
 | 
|---|
| 565 |                 //      __attribute__((cleanup( `finally_wrapper` )));
 | 
|---|
| 566 | 
 | 
|---|
| 567 |                 // Make Cleanup Attribute.
 | 
|---|
| 568 |                 std::list< Attribute * > attributes;
 | 
|---|
| 569 |                 {
 | 
|---|
| 570 |                         std::list< Expression * > attr_params;
 | 
|---|
| 571 |                         attr_params.push_back( nameOf( finally_wrapper ) );
 | 
|---|
| 572 |                         attributes.push_back( new Attribute( "cleanup", attr_params ) );
 | 
|---|
| 573 |                 }
 | 
|---|
| 574 | 
 | 
|---|
| 575 |                 return new ObjectDecl(
 | 
|---|
| 576 |                         "__finally_hook",
 | 
|---|
| 577 |                         Type::StorageClasses(),
 | 
|---|
| 578 |                         LinkageSpec::Cforall,
 | 
|---|
| 579 |                         nullptr,
 | 
|---|
| 580 |                         new StructInstType(
 | 
|---|
| 581 |                                 noQualifiers,
 | 
|---|
| 582 |                                 hook_decl
 | 
|---|
| 583 |                                 ),
 | 
|---|
| 584 |                         nullptr,
 | 
|---|
| 585 |                         attributes
 | 
|---|
| 586 |                         );
 | 
|---|
| 587 |         }
 | 
|---|
| 588 | 
 | 
|---|
| 589 |         Statement * TryMutatorCore::create_resume_rethrow( ThrowStmt *throwStmt ) {
 | 
|---|
| 590 |                 // return false;
 | 
|---|
| 591 |                 Statement * result = new ReturnStmt(
 | 
|---|
| 592 |                         new ConstantExpr( Constant::from_bool( false ) )
 | 
|---|
| 593 |                         );
 | 
|---|
| 594 |                 result->labels = throwStmt->labels;
 | 
|---|
| 595 |                 delete throwStmt;
 | 
|---|
| 596 |                 return result;
 | 
|---|
| 597 |         }
 | 
|---|
| 598 | 
 | 
|---|
| 599 |         // Visiting/Mutating Functions
 | 
|---|
| 600 |         void TryMutatorCore::premutate( StructDecl *structDecl ) {
 | 
|---|
| 601 |                 if ( !structDecl->has_body() ) {
 | 
|---|
| 602 |                         // Skip children?
 | 
|---|
| 603 |                         return;
 | 
|---|
| 604 |                 } else if ( structDecl->get_name() == "__cfaehm_base_exception_t" ) {
 | 
|---|
| 605 |                         assert( nullptr == except_decl );
 | 
|---|
| 606 |                         except_decl = structDecl;
 | 
|---|
| 607 |                         init_func_types();
 | 
|---|
| 608 |                 } else if ( structDecl->get_name() == "__cfaehm_try_resume_node" ) {
 | 
|---|
| 609 |                         assert( nullptr == node_decl );
 | 
|---|
| 610 |                         node_decl = structDecl;
 | 
|---|
| 611 |                 } else if ( structDecl->get_name() == "__cfaehm_cleanup_hook" ) {
 | 
|---|
| 612 |                         assert( nullptr == hook_decl );
 | 
|---|
| 613 |                         hook_decl = structDecl;
 | 
|---|
| 614 |                 }
 | 
|---|
| 615 |         }
 | 
|---|
| 616 | 
 | 
|---|
| 617 |         Statement * TryMutatorCore::postmutate( TryStmt *tryStmt ) {
 | 
|---|
| 618 |                 assert( except_decl );
 | 
|---|
| 619 |                 assert( node_decl );
 | 
|---|
| 620 |                 assert( hook_decl );
 | 
|---|
| 621 | 
 | 
|---|
| 622 |                 // Generate a prefix for the function names?
 | 
|---|
| 623 | 
 | 
|---|
| 624 |                 CompoundStmt * block = new CompoundStmt();
 | 
|---|
| 625 |                 CompoundStmt * inner = take_try_block( tryStmt );
 | 
|---|
| 626 | 
 | 
|---|
| 627 |                 if ( tryStmt->get_finally() ) {
 | 
|---|
| 628 |                         // Define the helper function.
 | 
|---|
| 629 |                         FunctionDecl * finally_block =
 | 
|---|
| 630 |                                 create_finally_wrapper( tryStmt );
 | 
|---|
| 631 |                         appendDeclStmt( block, finally_block );
 | 
|---|
| 632 |                         // Create and add the finally cleanup hook.
 | 
|---|
| 633 |                         appendDeclStmt( block, create_finally_hook( finally_block ) );
 | 
|---|
| 634 |                 }
 | 
|---|
| 635 | 
 | 
|---|
| 636 |                 CatchList termination_handlers;
 | 
|---|
| 637 |                 CatchList resumption_handlers;
 | 
|---|
| 638 |                 split( tryStmt->get_catchers(),
 | 
|---|
| 639 |                            termination_handlers, resumption_handlers );
 | 
|---|
| 640 | 
 | 
|---|
| 641 |                 if ( resumption_handlers.size() ) {
 | 
|---|
| 642 |                         // Define the helper function.
 | 
|---|
| 643 |                         FunctionDecl * resume_handler =
 | 
|---|
| 644 |                                 create_resume_handler( resumption_handlers );
 | 
|---|
| 645 |                         appendDeclStmt( block, resume_handler );
 | 
|---|
| 646 |                         // Prepare hooks
 | 
|---|
| 647 |                         inner = create_resume_wrapper( inner, resume_handler );
 | 
|---|
| 648 |                 }
 | 
|---|
| 649 | 
 | 
|---|
| 650 |                 if ( termination_handlers.size() ) {
 | 
|---|
| 651 |                         // Define the three helper functions.
 | 
|---|
| 652 |                         FunctionDecl * try_wrapper = create_try_wrapper( inner );
 | 
|---|
| 653 |                         appendDeclStmt( block, try_wrapper );
 | 
|---|
| 654 |                         FunctionDecl * terminate_catch =
 | 
|---|
| 655 |                                 create_terminate_catch( termination_handlers );
 | 
|---|
| 656 |                         appendDeclStmt( block, terminate_catch );
 | 
|---|
| 657 |                         FunctionDecl * terminate_match =
 | 
|---|
| 658 |                                 create_terminate_match( termination_handlers );
 | 
|---|
| 659 |                         appendDeclStmt( block, terminate_match );
 | 
|---|
| 660 |                         // Build the call to the try wrapper.
 | 
|---|
| 661 |                         inner = create_terminate_caller(
 | 
|---|
| 662 |                                 try_wrapper, terminate_catch, terminate_match );
 | 
|---|
| 663 |                 }
 | 
|---|
| 664 | 
 | 
|---|
| 665 |                 // Embed the try block.
 | 
|---|
| 666 |                 block->push_back( inner );
 | 
|---|
| 667 | 
 | 
|---|
| 668 |                 return block;
 | 
|---|
| 669 |         }
 | 
|---|
| 670 | 
 | 
|---|
| 671 |         Statement * TryMutatorCore::postmutate( ThrowStmt *throwStmt ) {
 | 
|---|
| 672 |                 // Only valid `throwResume;` statements should remain. (2/3 checks)
 | 
|---|
| 673 |                 assert( ThrowStmt::Resume == throwStmt->kind && ! throwStmt->expr );
 | 
|---|
| 674 |                 return create_resume_rethrow( throwStmt );
 | 
|---|
| 675 |         }
 | 
|---|
| 676 | 
 | 
|---|
| 677 |         void translateThrows( std::list< Declaration *> & translationUnit ) {
 | 
|---|
| 678 |                 PassVisitor<ThrowMutatorCore> translator;
 | 
|---|
| 679 |                 mutateAll( translationUnit, translator );
 | 
|---|
| 680 |         }
 | 
|---|
| 681 | 
 | 
|---|
| 682 |         void translateTries( std::list< Declaration *> & translationUnit ) {
 | 
|---|
| 683 |                 PassVisitor<TryMutatorCore> translator;
 | 
|---|
| 684 |                 mutateAll( translationUnit, translator );
 | 
|---|
| 685 |         }
 | 
|---|
| 686 | }
 | 
|---|