| 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 | // ExceptTranslate.cpp -- Conversion of exception control flow structures.
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| 8 | //
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| 9 | // Author : Andrew Beach
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| 10 | // Created On : Mon Nov 8 11:53:00 2021
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| 11 | // Last Modified By : Andrew Beach
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| 12 | // Last Modified On : Fri Mar 11 17:51:00 2022
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| 13 | // Update Count : 2
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| 14 | //
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| 15 |
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| 16 | #include "ExceptTranslate.hpp"
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| 17 |
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| 18 | #include "AST/Expr.hpp"
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| 19 | #include "AST/Pass.hpp"
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| 20 | #include "AST/Stmt.hpp"
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| 21 | #include "AST/TranslationUnit.hpp"
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| 22 | #include "AST/DeclReplacer.hpp"
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| 23 |
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| 24 | namespace ControlStruct {
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| 25 |
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| 26 | namespace {
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| 27 |
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| 28 | typedef std::list<ast::CatchClause*> CatchList;
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| 29 |
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| 30 | void appendDeclStmt( ast::CompoundStmt * block, ast::DeclWithType * item ) {
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| 31 | block->push_back( new ast::DeclStmt( block->location, item ) );
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| 32 | }
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| 33 |
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| 34 | class TranslateThrowsCore final : public ast::WithGuards {
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| 35 | const ast::ObjectDecl * terminateHandlerExcept;
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| 36 | enum Context { NoHandler, TerHandler, ResHandler } currentContext;
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| 37 |
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| 38 | const ast::Stmt * createEitherThrow(
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| 39 | const ast::ThrowStmt * throwStmt, const char * funcName );
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| 40 | const ast::Stmt * createTerminateRethrow( const ast::ThrowStmt * );
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| 41 |
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| 42 | public:
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| 43 | TranslateThrowsCore() :
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| 44 | terminateHandlerExcept( nullptr ), currentContext( NoHandler )
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| 45 | {}
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| 46 |
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| 47 | void previsit( const ast::CatchClause * stmt );
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| 48 | const ast::Stmt * postvisit( const ast::ThrowStmt * stmt );
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| 49 | };
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| 50 |
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| 51 | const ast::Stmt * TranslateThrowsCore::createEitherThrow(
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| 52 | const ast::ThrowStmt * throwStmt, const char * funcName ) {
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| 53 | // `throwFunc`( `throwStmt->name` );
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| 54 | ast::UntypedExpr * call = new ast::UntypedExpr( throwStmt->location,
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| 55 | new ast::NameExpr( throwStmt->location, funcName )
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| 56 | );
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| 57 | call->args.push_back( throwStmt->expr );
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| 58 | return new ast::ExprStmt( throwStmt->location, call );
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| 59 | }
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| 60 |
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| 61 | ast::VariableExpr * varOf( const ast::DeclWithType * decl ) {
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| 62 | return new ast::VariableExpr( decl->location, decl );
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| 63 | }
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| 64 |
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| 65 | const ast::Stmt * TranslateThrowsCore::createTerminateRethrow(
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| 66 | const ast::ThrowStmt * stmt ) {
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| 67 | // { `terminate_handler_except` = 0p; __rethrow_terminate(); }
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| 68 | assert( nullptr == stmt->expr );
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| 69 | assert( terminateHandlerExcept );
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| 70 |
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| 71 | ast::CompoundStmt * result = new ast::CompoundStmt(
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| 72 | stmt->location, {}, std::vector<ast::Label>( stmt->labels ) );
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| 73 | result->push_back( new ast::ExprStmt( stmt->location,
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| 74 | ast::UntypedExpr::createAssign(
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| 75 | stmt->location,
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| 76 | varOf( terminateHandlerExcept ),
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| 77 | ast::ConstantExpr::null(
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| 78 | stmt->location,
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| 79 | terminateHandlerExcept->type
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| 80 | )
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| 81 | )
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| 82 | ) );
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| 83 | result->push_back( new ast::ExprStmt( stmt->location, new ast::UntypedExpr(
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| 84 | stmt->location,
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| 85 | new ast::NameExpr( stmt->location, "__cfaehm_rethrow_terminate" )
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| 86 | ) ) );
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| 87 | return result;
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| 88 | }
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| 89 |
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| 90 | void TranslateThrowsCore::previsit( const ast::CatchClause * stmt ) {
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| 91 | // Validate the statement's form.
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| 92 | const ast::ObjectDecl * decl = stmt->decl.as<ast::ObjectDecl>();
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| 93 | // Also checking the type would be nice.
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| 94 | if ( !decl || !decl->type.as<ast::PointerType>() ) {
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| 95 | std::string kind = (ast::Terminate == stmt->kind) ? "catch" : "catchResume";
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| 96 | SemanticError( stmt->location, kind + " must have pointer to an exception type" );
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| 97 | }
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| 98 |
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| 99 | // Track the handler context.
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| 100 | if ( ast::Terminate == stmt->kind ) {
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| 101 | GuardValue( currentContext ) = TerHandler;
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| 102 | GuardValue( terminateHandlerExcept ) = decl;
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| 103 | } else {
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| 104 | GuardValue( currentContext ) = ResHandler;
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| 105 | }
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| 106 | }
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| 107 |
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| 108 | const ast::Stmt * TranslateThrowsCore::postvisit(
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| 109 | const ast::ThrowStmt * stmt ) {
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| 110 | // Ignoring ThrowStmt::target for now.
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| 111 | // Handle Termination (Raise, Reraise, Error):
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| 112 | if ( ast::Terminate == stmt->kind ) {
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| 113 | if ( stmt->expr ) {
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| 114 | return createEitherThrow( stmt, "$throw" );
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| 115 | } else if ( TerHandler == currentContext ) {
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| 116 | return createTerminateRethrow( stmt );
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| 117 | } else {
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| 118 | abort( "Invalid throw in %s at %i\n",
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| 119 | stmt->location.filename.c_str(),
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| 120 | stmt->location.first_line);
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| 121 | }
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| 122 | // Handle Resumption (Raise, Reraise, Error):
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| 123 | } else {
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| 124 | if ( stmt->expr ) {
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| 125 | return createEitherThrow( stmt, "$throwResume" );
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| 126 | } else if ( ResHandler == currentContext ) {
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| 127 | // This has to be handled later.
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| 128 | return stmt;
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| 129 | } else {
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| 130 | abort( "Invalid throwResume in %s at %i\n",
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| 131 | stmt->location.filename.c_str(),
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| 132 | stmt->location.first_line);
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| 133 | }
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| 134 | }
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| 135 | }
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| 136 |
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| 137 |
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| 138 | class TryMutatorCore final {
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| 139 | // The built in types used in translation.
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| 140 | const ast::StructDecl * except_decl;
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| 141 | const ast::StructDecl * node_decl;
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| 142 | const ast::StructDecl * hook_decl;
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| 143 |
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| 144 | // The many helper functions for code/syntree generation.
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| 145 | ast::CompoundStmt * take_try_block( ast::TryStmt * tryStmt );
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| 146 | ast::FunctionDecl * create_try_wrapper( const ast::CompoundStmt * body );
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| 147 | ast::CaseClause * create_terminate_catch_case(
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| 148 | const ast::DeclWithType * except_obj, int index, ast::CatchClause * clause );
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| 149 | ast::CompoundStmt * create_single_matcher(
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| 150 | const ast::DeclWithType * except_obj, ast::CatchClause * modded_handler );
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| 151 | ast::FunctionDecl * create_terminate_match( CatchList &handlers );
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| 152 | ast::CompoundStmt * create_terminate_caller( const CodeLocation & location,
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| 153 | ast::FunctionDecl * try_wrapper, ast::FunctionDecl * terminate_match,
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| 154 | CatchList & terminate_handlers );
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| 155 | ast::FunctionDecl * create_resume_handler( CatchList &handlers );
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| 156 | ast::CompoundStmt * create_resume_wrapper(
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| 157 | const ast::Stmt * wraps, const ast::FunctionDecl * resume_handler );
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| 158 | ast::FunctionDecl * create_finally_wrapper( ast::TryStmt * tryStmt );
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| 159 | ast::ObjectDecl * create_finally_hook( ast::FunctionDecl * finally_wrapper );
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| 160 | ast::Stmt * create_resume_rethrow( const ast::ThrowStmt * throwStmt );
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| 161 |
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| 162 | // Types used in translation, first group are internal.
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| 163 | ast::ObjectDecl * make_index_object( CodeLocation const & ) const;
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| 164 | ast::ObjectDecl * make_exception_object( CodeLocation const & ) const;
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| 165 | ast::ObjectDecl * make_bool_object( CodeLocation const & ) const;
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| 166 | ast::ObjectDecl * make_voidptr_object( CodeLocation const & ) const;
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| 167 | ast::ObjectDecl * make_unused_index_object( CodeLocation const & ) const;
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| 168 |
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| 169 | public:
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| 170 | TryMutatorCore() :
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| 171 | except_decl( nullptr ), node_decl( nullptr ), hook_decl( nullptr )
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| 172 | {}
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| 173 |
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| 174 | void previsit( const ast::StructDecl *structDecl );
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| 175 | ast::Stmt * postvisit( const ast::TryStmt *tryStmt );
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| 176 | ast::Stmt * postvisit( const ast::ThrowStmt *throwStmt );
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| 177 | };
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| 178 |
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| 179 | ast::ObjectDecl * TryMutatorCore::make_index_object(
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| 180 | CodeLocation const & location ) const {
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| 181 | return new ast::ObjectDecl(
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| 182 | location,
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| 183 | "__handler_index",
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| 184 | new ast::BasicType( ast::BasicKind::SignedInt )
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| 185 | );
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| 186 | }
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| 187 |
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| 188 | ast::ObjectDecl * TryMutatorCore::make_exception_object(
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| 189 | CodeLocation const & location ) const {
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| 190 | assert( except_decl );
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| 191 | return new ast::ObjectDecl(
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| 192 | location,
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| 193 | "__exception_inst",
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| 194 | new ast::PointerType( new ast::StructInstType( except_decl ) )
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| 195 | );
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| 196 | }
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| 197 |
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| 198 | ast::ObjectDecl * TryMutatorCore::make_bool_object(
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| 199 | CodeLocation const & location ) const {
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| 200 | return new ast::ObjectDecl(
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| 201 | location,
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| 202 | "__ret_bool",
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| 203 | new ast::BasicType( ast::BasicKind::Bool ),
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| 204 | nullptr, //init
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| 205 | ast::Storage::Classes{},
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| 206 | ast::Linkage::Cforall,
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| 207 | nullptr, //width
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| 208 | std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) }
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| 209 | );
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| 210 | }
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| 211 |
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| 212 | ast::ObjectDecl * TryMutatorCore::make_voidptr_object(
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| 213 | CodeLocation const & location ) const {
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| 214 | return new ast::ObjectDecl(
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| 215 | location,
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| 216 | "__hook",
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| 217 | new ast::PointerType(
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| 218 | new ast::VoidType()
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| 219 | ),
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| 220 | nullptr, //init
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| 221 | ast::Storage::Classes{},
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| 222 | ast::Linkage::Cforall,
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| 223 | nullptr, //width
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| 224 | std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) }
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| 225 | );
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| 226 | }
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| 227 |
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| 228 | ast::ObjectDecl * TryMutatorCore::make_unused_index_object(
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| 229 | CodeLocation const & location ) const {
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| 230 | return new ast::ObjectDecl(
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| 231 | location,
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| 232 | "__handler_index",
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| 233 | new ast::BasicType( ast::BasicKind::SignedInt ),
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| 234 | nullptr,
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| 235 | ast::Storage::Classes{},
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| 236 | ast::Linkage::Cforall,
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| 237 | nullptr, //width
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| 238 | std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) }
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| 239 | );
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| 240 | }
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| 241 |
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| 242 | // TryStmt Mutation Helpers
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| 243 |
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| 244 | ast::FunctionDecl * TryMutatorCore::create_try_wrapper(
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| 245 | const ast::CompoundStmt *body ) {
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| 246 | // void (*try)(void) `body`
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| 247 | return new ast::FunctionDecl(
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| 248 | body->location,
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| 249 | "try",
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| 250 | {}, //no param
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| 251 | {}, //no return
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| 252 | ast::mutate( body ),
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| 253 | ast::Storage::Classes{},
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| 254 | ast::Linkage::Cforall
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| 255 | );
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| 256 | }
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| 257 |
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| 258 | ast::CaseClause * TryMutatorCore::create_terminate_catch_case(
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| 259 | const ast::DeclWithType * except_obj, int index, ast::CatchClause * clause ) {
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| 260 | // case `index`:
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| 261 | // {
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| 262 | // __attribute__((cleanup(__cfaehm_cleanup_terminate)))
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| 263 | // `handler.decl` = { (virtual `decl.type`)`except` };
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| 264 | // `handler.body`;
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| 265 | // }
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| 266 | // break;
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| 267 | const CodeLocation & location = clause->location;
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| 268 |
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| 269 | auto clause_except = clause->decl.strict_as<ast::ObjectDecl>();
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| 270 | auto local_except = ast::deepCopy( clause_except );
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| 271 | local_except->attributes.push_back( new ast::Attribute(
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| 272 | "cleanup",
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| 273 | { new ast::NameExpr( location, "__cfaehm_cleanup_terminate" ) }
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| 274 | ) );
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| 275 |
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| 276 | local_except->init = new ast::ListInit( location, {
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| 277 | new ast::SingleInit( location,
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| 278 | new ast::VirtualCastExpr( location,
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| 279 | new ast::VariableExpr( location, except_obj ),
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| 280 | ast::deepCopy( local_except->get_type() )
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| 281 | )
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| 282 | )
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| 283 | } );
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| 284 |
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| 285 | ast::DeclReplacer::DeclMap mapping;
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| 286 | mapping[clause_except] = local_except;
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| 287 | const ast::Stmt * body = strict_dynamic_cast<const ast::Stmt *>(
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| 288 | ast::DeclReplacer::replace(clause->body, mapping));
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| 289 |
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| 290 | return new ast::CaseClause( location,
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| 291 | ast::ConstantExpr::from_int( location, index ),
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| 292 | {
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| 293 | new ast::CompoundStmt( location, {
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| 294 | new ast::DeclStmt( location, local_except ),
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| 295 | body,
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| 296 | } ),
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| 297 | new ast::BranchStmt( location, ast::BranchStmt::Break,
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| 298 | ast::Label( location ) ),
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| 299 | }
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| 300 | );
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| 301 | }
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| 302 |
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| 303 | // Create a single check from a moddified handler.
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| 304 | // except_obj is referenced, modded_handler will be freed.
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| 305 | ast::CompoundStmt * TryMutatorCore::create_single_matcher(
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| 306 | const ast::DeclWithType * except_obj, ast::CatchClause * modded_handler ) {
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| 307 | // {
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| 308 | // `modded_handler.decl`
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| 309 | // if ( `decl.name = (virtual `decl.type`)`except`
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| 310 | // [&& `modded_handler.cond`] ) {
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| 311 | // `modded_handler.body`
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| 312 | // }
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| 313 | // }
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| 314 |
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| 315 | const CodeLocation loc = modded_handler->location;
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| 316 | ast::CompoundStmt * block = new ast::CompoundStmt(loc);
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| 317 |
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| 318 | // Local Declaration
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| 319 | const ast::ObjectDecl * local_except =
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| 320 | modded_handler->decl.strict_as<ast::ObjectDecl>();
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| 321 | block->push_back( new ast::DeclStmt( loc, local_except ) );
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| 322 |
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| 323 | // Check for type match.
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| 324 | ast::VirtualCastExpr * vcex = new ast::VirtualCastExpr(loc,
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| 325 | new ast::VariableExpr(loc, except_obj ),
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| 326 | local_except->get_type()
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| 327 | );
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| 328 | ast::Expr * cond = ast::UntypedExpr::createAssign(loc,
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| 329 | new ast::VariableExpr(loc, local_except ), vcex );
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| 330 |
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| 331 | // Add the check on the conditional if it is provided.
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| 332 | if ( modded_handler->cond ) {
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| 333 | cond = new ast::LogicalExpr( loc, cond, modded_handler->cond, ast::LogicalFlag::AndExpr );
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| 334 | }
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| 335 | // Construct the match condition.
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| 336 | block->push_back( new ast::IfStmt(loc,
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| 337 | cond, modded_handler->body, nullptr ) );
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| 338 |
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| 339 | return block;
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| 340 | }
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| 341 |
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| 342 | ast::FunctionDecl * TryMutatorCore::create_terminate_match(
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| 343 | CatchList &handlers ) {
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| 344 | // int match(exception * except) {
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| 345 | // HANDLER WRAPPERS { return `index`; }
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| 346 | // }
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| 347 |
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| 348 | assert( !handlers.empty() );
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| 349 | const CodeLocation & location = handlers.front()->location;
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| 350 |
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| 351 | ast::CompoundStmt * body = new ast::CompoundStmt( location );
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| 352 | const ast::DeclWithType * except_obj = make_exception_object( location );
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| 353 |
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| 354 | // Index 1..{number of handlers}
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| 355 | int index = 0;
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| 356 | for ( ast::CatchClause * handler : handlers ) {
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| 357 | ++index;
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| 358 |
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| 359 | ast::ptr<ast::Stmt> other_body = new ast::ReturnStmt( handler->location,
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| 360 | ast::ConstantExpr::from_int( handler->location, index ) );
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| 361 | handler->body.swap( other_body );
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| 362 |
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| 363 | body->push_back( create_single_matcher( except_obj, handler ) );
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| 364 |
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| 365 | handler->body.swap( other_body );
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| 366 | }
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| 367 |
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| 368 | body->push_back( new ast::ReturnStmt( location,
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| 369 | ast::ConstantExpr::from_int( location, 0 ) ));
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| 370 |
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| 371 | // void (*match)(exception_t *) `body`
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| 372 | return new ast::FunctionDecl(
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| 373 | location,
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| 374 | "match",
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| 375 | { except_obj },
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| 376 | { make_unused_index_object( location ) },
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| 377 | body,
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| 378 | ast::Storage::Classes{},
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| 379 | ast::Linkage::Cforall
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| 380 | );
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| 381 | }
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| 382 |
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| 383 | ast::CompoundStmt * TryMutatorCore::create_terminate_caller(
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| 384 | const CodeLocation & loc,
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| 385 | ast::FunctionDecl * try_wrapper,
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| 386 | ast::FunctionDecl * terminate_match,
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| 387 | CatchList & terminate_handlers ) {
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| 388 | // {
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| 389 | // int __handler_index = __cfaehm_try_terminate(`try`, `match`);
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| 390 | // if ( __handler_index ) {
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| 391 | // `catch`( __handler_index, __cfaehm_get_current_termination() );
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| 392 | // }
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| 393 | // }
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| 394 |
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| 395 | ast::ObjectDecl * index = make_index_object( loc );
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| 396 | index->init = new ast::SingleInit( loc,
|
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| 397 | new ast::UntypedExpr( loc,
|
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| 398 | new ast::NameExpr( loc, "__cfaehm_try_terminate" ),
|
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| 399 | {
|
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| 400 | new ast::VariableExpr( loc, try_wrapper ),
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| 401 | new ast::VariableExpr( loc, terminate_match ),
|
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| 402 | }
|
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| 403 | )
|
|---|
| 404 | );
|
|---|
| 405 |
|
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| 406 | ast::ObjectDecl * except = make_exception_object( loc );
|
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| 407 | except->init = new ast::SingleInit( loc,
|
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| 408 | new ast::UntypedExpr( loc,
|
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| 409 | new ast::NameExpr( loc, "__cfaehm_get_current_termination" )
|
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| 410 | )
|
|---|
| 411 | );
|
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| 412 |
|
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| 413 | std::vector<ast::ptr<ast::CaseClause>> cases;
|
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| 414 | for ( auto const & [index, handler] : enumerate( terminate_handlers ) ) {
|
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| 415 | cases.emplace_back(
|
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| 416 | create_terminate_catch_case( except, index + 1, handler ) );
|
|---|
| 417 | }
|
|---|
| 418 | auto switch_stmt = new ast::SwitchStmt( loc,
|
|---|
| 419 | new ast::VariableExpr( loc, index ), std::move( cases ) );
|
|---|
| 420 |
|
|---|
| 421 | return new ast::CompoundStmt( loc, {
|
|---|
| 422 | new ast::DeclStmt( loc, index ),
|
|---|
| 423 | new ast::IfStmt( loc,
|
|---|
| 424 | new ast::VariableExpr( loc, index ),
|
|---|
| 425 | new ast::CompoundStmt( loc, {
|
|---|
| 426 | new ast::DeclStmt( loc, except ),
|
|---|
| 427 | switch_stmt,
|
|---|
| 428 | } )
|
|---|
| 429 | ),
|
|---|
| 430 | } );
|
|---|
| 431 | }
|
|---|
| 432 |
|
|---|
| 433 | ast::FunctionDecl * TryMutatorCore::create_resume_handler(
|
|---|
| 434 | CatchList &handlers ) {
|
|---|
| 435 | // bool handle(exception * except) {
|
|---|
| 436 | // HANDLER WRAPPERS { `hander->body`; return true; }
|
|---|
| 437 | // }
|
|---|
| 438 |
|
|---|
| 439 | assert( !handlers.empty() );
|
|---|
| 440 | const CodeLocation & location = handlers.front()->location;
|
|---|
| 441 |
|
|---|
| 442 | ast::CompoundStmt * body = new ast::CompoundStmt( location );
|
|---|
| 443 | const ast::DeclWithType * except_obj = make_exception_object( location );
|
|---|
| 444 |
|
|---|
| 445 | CatchList::iterator it;
|
|---|
| 446 | for ( it = handlers.begin() ; it != handlers.end() ; ++it ) {
|
|---|
| 447 | ast::CatchClause * handler = *it;
|
|---|
| 448 | const CodeLocation loc = handler->location;
|
|---|
| 449 | // Modifiy body.
|
|---|
| 450 | ast::CompoundStmt * handling_code;
|
|---|
| 451 | if (handler->body.as<ast::CompoundStmt>()) {
|
|---|
| 452 | handling_code = strict_dynamic_cast<ast::CompoundStmt*>(
|
|---|
| 453 | handler->body.get_and_mutate() );
|
|---|
| 454 | } else {
|
|---|
| 455 | handling_code = new ast::CompoundStmt(loc);
|
|---|
| 456 | handling_code->push_back( handler->body );
|
|---|
| 457 | }
|
|---|
| 458 | handling_code->push_back( new ast::ReturnStmt(loc,
|
|---|
| 459 | ast::ConstantExpr::from_bool(loc, true ) ) );
|
|---|
| 460 | handler->body = handling_code;
|
|---|
| 461 |
|
|---|
| 462 | // Create the handler.
|
|---|
| 463 | body->push_back( create_single_matcher( except_obj, handler ) );
|
|---|
| 464 | *it = nullptr;
|
|---|
| 465 | }
|
|---|
| 466 |
|
|---|
| 467 | body->push_back( new ast::ReturnStmt( location,
|
|---|
| 468 | ast::ConstantExpr::from_bool( location, false ) ) );
|
|---|
| 469 |
|
|---|
| 470 | // bool (*handle)(exception_t *) `body`
|
|---|
| 471 | return new ast::FunctionDecl(
|
|---|
| 472 | location,
|
|---|
| 473 | "handle",
|
|---|
| 474 | { except_obj },
|
|---|
| 475 | { make_bool_object( location ) },
|
|---|
| 476 | body,
|
|---|
| 477 | ast::Storage::Classes{},
|
|---|
| 478 | ast::Linkage::Cforall
|
|---|
| 479 | );
|
|---|
| 480 | }
|
|---|
| 481 |
|
|---|
| 482 | ast::CompoundStmt * TryMutatorCore::create_resume_wrapper(
|
|---|
| 483 | const ast::Stmt * wraps,
|
|---|
| 484 | const ast::FunctionDecl * resume_handler ) {
|
|---|
| 485 | const CodeLocation loc = wraps->location;
|
|---|
| 486 | ast::CompoundStmt * body = new ast::CompoundStmt(loc);
|
|---|
| 487 |
|
|---|
| 488 | // struct __try_resume_node __resume_node
|
|---|
| 489 | // __attribute__((cleanup( __cfaehm_try_resume_cleanup )));
|
|---|
| 490 | // ** unwinding of the stack here could cause problems **
|
|---|
| 491 | // ** however I don't think that can happen currently **
|
|---|
| 492 | // __cfaehm_try_resume_setup( &__resume_node, resume_handler );
|
|---|
| 493 |
|
|---|
| 494 | ast::ObjectDecl * obj = new ast::ObjectDecl(
|
|---|
| 495 | loc,
|
|---|
| 496 | "__resume_node",
|
|---|
| 497 | new ast::StructInstType(
|
|---|
| 498 | node_decl
|
|---|
| 499 | ),
|
|---|
| 500 | nullptr,
|
|---|
| 501 | ast::Storage::Classes{},
|
|---|
| 502 | ast::Linkage::Cforall,
|
|---|
| 503 | nullptr,
|
|---|
| 504 | {new ast::Attribute("cleanup", {new ast::NameExpr(loc, "__cfaehm_try_resume_cleanup")})}
|
|---|
| 505 | );
|
|---|
| 506 | appendDeclStmt( body, obj );
|
|---|
| 507 |
|
|---|
| 508 | ast::UntypedExpr *setup = new ast::UntypedExpr(loc, new ast::NameExpr(loc,
|
|---|
| 509 | "__cfaehm_try_resume_setup" ) );
|
|---|
| 510 | setup->args.push_back( new ast::AddressExpr( loc, new ast::VariableExpr(loc, obj ) ) );
|
|---|
| 511 | setup->args.push_back( new ast::VariableExpr( loc, resume_handler ) );
|
|---|
| 512 |
|
|---|
| 513 | body->push_back( new ast::ExprStmt(loc, setup ) );
|
|---|
| 514 |
|
|---|
| 515 | body->push_back( wraps );
|
|---|
| 516 | return body;
|
|---|
| 517 | }
|
|---|
| 518 |
|
|---|
| 519 | ast::FunctionDecl * TryMutatorCore::create_finally_wrapper(
|
|---|
| 520 | ast::TryStmt * tryStmt ) {
|
|---|
| 521 | // void finally(__attribute__((unused)) void *) `finally->body`
|
|---|
| 522 | const ast::FinallyClause * finally = tryStmt->finally;
|
|---|
| 523 | return new ast::FunctionDecl(
|
|---|
| 524 | tryStmt->location,
|
|---|
| 525 | "finally",
|
|---|
| 526 | { make_voidptr_object( tryStmt->location ) },
|
|---|
| 527 | {}, //return void
|
|---|
| 528 | ast::mutate( finally->body.get() ),
|
|---|
| 529 | ast::Storage::Classes{},
|
|---|
| 530 | ast::Linkage::Cforall,
|
|---|
| 531 | {},
|
|---|
| 532 | { ast::Function::Inline }
|
|---|
| 533 | );
|
|---|
| 534 | }
|
|---|
| 535 |
|
|---|
| 536 | ast::ObjectDecl * TryMutatorCore::create_finally_hook(
|
|---|
| 537 | ast::FunctionDecl * finally_wrapper ) {
|
|---|
| 538 | // struct __cfaehm_cleanup_hook __finally_hook
|
|---|
| 539 | // __attribute__((cleanup( `finally_wrapper` )));
|
|---|
| 540 |
|
|---|
| 541 | const CodeLocation & location = finally_wrapper->location;
|
|---|
| 542 | return new ast::ObjectDecl(
|
|---|
| 543 | location,
|
|---|
| 544 | "__finally_hook",
|
|---|
| 545 | new ast::StructInstType(
|
|---|
| 546 | hook_decl
|
|---|
| 547 | ),
|
|---|
| 548 | nullptr,
|
|---|
| 549 | ast::Storage::Classes{},
|
|---|
| 550 | ast::Linkage::Cforall,
|
|---|
| 551 | nullptr,
|
|---|
| 552 | {new ast::Attribute("cleanup", {new ast::VariableExpr(location, finally_wrapper)})}
|
|---|
| 553 | );
|
|---|
| 554 | }
|
|---|
| 555 |
|
|---|
| 556 | ast::Stmt * TryMutatorCore::create_resume_rethrow( const ast::ThrowStmt *throwStmt ) {
|
|---|
| 557 | // return false;
|
|---|
| 558 | const CodeLocation loc = throwStmt->location;
|
|---|
| 559 | ast::Stmt * result = new ast::ReturnStmt(loc,
|
|---|
| 560 | ast::ConstantExpr::from_bool( loc, false )
|
|---|
| 561 | );
|
|---|
| 562 | result->labels = throwStmt->labels;
|
|---|
| 563 | return result;
|
|---|
| 564 | }
|
|---|
| 565 |
|
|---|
| 566 | // Visiting/Mutating Functions
|
|---|
| 567 | void TryMutatorCore::previsit( const ast::StructDecl *structDecl ) {
|
|---|
| 568 | if ( !structDecl->body ) {
|
|---|
| 569 | // Skip children?
|
|---|
| 570 | return;
|
|---|
| 571 | } else if ( structDecl->name == "__cfaehm_base_exception_t" ) {
|
|---|
| 572 | assert( nullptr == except_decl );
|
|---|
| 573 | except_decl = structDecl;
|
|---|
| 574 | } else if ( structDecl->name == "__cfaehm_try_resume_node" ) {
|
|---|
| 575 | assert( nullptr == node_decl );
|
|---|
| 576 | node_decl = structDecl;
|
|---|
| 577 | } else if ( structDecl->name == "__cfaehm_cleanup_hook" ) {
|
|---|
| 578 | assert( nullptr == hook_decl );
|
|---|
| 579 | hook_decl = structDecl;
|
|---|
| 580 | }
|
|---|
| 581 | }
|
|---|
| 582 |
|
|---|
| 583 | ast::Stmt * TryMutatorCore::postvisit( const ast::TryStmt *tryStmt ) {
|
|---|
| 584 | assert( except_decl );
|
|---|
| 585 | assert( node_decl );
|
|---|
| 586 | assert( hook_decl );
|
|---|
| 587 |
|
|---|
| 588 | const CodeLocation loc = tryStmt->location;
|
|---|
| 589 | ast::TryStmt * mutStmt = mutate(tryStmt);
|
|---|
| 590 | // Generate a prefix for the function names?
|
|---|
| 591 |
|
|---|
| 592 | ast::CompoundStmt * block = new ast::CompoundStmt( loc );
|
|---|
| 593 | // ast::CompoundStmt * inner = take_try_block( mutStmt );
|
|---|
| 594 | // this is never mutated so let node deletion do its job?
|
|---|
| 595 | const ast::CompoundStmt * inner = mutStmt->body;
|
|---|
| 596 |
|
|---|
| 597 | if ( mutStmt->finally ) {
|
|---|
| 598 | // Define the helper function.
|
|---|
| 599 | ast::FunctionDecl * finally_block =
|
|---|
| 600 | create_finally_wrapper( mutStmt );
|
|---|
| 601 | appendDeclStmt( block, finally_block );
|
|---|
| 602 | // Create and add the finally cleanup hook.
|
|---|
| 603 | appendDeclStmt( block, create_finally_hook( finally_block ) );
|
|---|
| 604 | }
|
|---|
| 605 |
|
|---|
| 606 | CatchList termination_handlers;
|
|---|
| 607 | CatchList resumption_handlers;
|
|---|
| 608 |
|
|---|
| 609 | for (auto & handler: mutStmt->handlers) {
|
|---|
| 610 | // xxx - should always be unique? mutate as safe const-cast
|
|---|
| 611 | assert(handler->unique());
|
|---|
| 612 | if (handler->kind == ast::ExceptionKind::Resume) {
|
|---|
| 613 | resumption_handlers.push_back(handler.get_and_mutate());
|
|---|
| 614 | }
|
|---|
| 615 | else {
|
|---|
| 616 | termination_handlers.push_back(handler.get_and_mutate());
|
|---|
| 617 | }
|
|---|
| 618 | }
|
|---|
| 619 |
|
|---|
| 620 | if ( resumption_handlers.size() ) {
|
|---|
| 621 | // Define the helper function.
|
|---|
| 622 | ast::FunctionDecl * resume_handler =
|
|---|
| 623 | create_resume_handler( resumption_handlers );
|
|---|
| 624 | appendDeclStmt( block, resume_handler );
|
|---|
| 625 | // Prepare hooks
|
|---|
| 626 | inner = create_resume_wrapper( inner, resume_handler );
|
|---|
| 627 | }
|
|---|
| 628 |
|
|---|
| 629 | if ( termination_handlers.size() ) {
|
|---|
| 630 | // Define the two helper functions.
|
|---|
| 631 | ast::FunctionDecl * try_wrapper = create_try_wrapper( inner );
|
|---|
| 632 | appendDeclStmt( block, try_wrapper );
|
|---|
| 633 | ast::FunctionDecl * terminate_match =
|
|---|
| 634 | create_terminate_match( termination_handlers );
|
|---|
| 635 | appendDeclStmt( block, terminate_match );
|
|---|
| 636 | // Build the call to the try wrapper.
|
|---|
| 637 | inner = create_terminate_caller(inner->location,
|
|---|
| 638 | try_wrapper, terminate_match, termination_handlers );
|
|---|
| 639 | }
|
|---|
| 640 |
|
|---|
| 641 | // Embed the try block.
|
|---|
| 642 | block->push_back( inner );
|
|---|
| 643 |
|
|---|
| 644 | return block;
|
|---|
| 645 | }
|
|---|
| 646 |
|
|---|
| 647 | ast::Stmt * TryMutatorCore::postvisit( const ast::ThrowStmt *throwStmt ) {
|
|---|
| 648 | // Only valid `throwResume;` statements should remain. (2/3 checks)
|
|---|
| 649 | assert( ast::ExceptionKind::Resume == throwStmt->kind && ! throwStmt->expr );
|
|---|
| 650 | return create_resume_rethrow( throwStmt );
|
|---|
| 651 | }
|
|---|
| 652 |
|
|---|
| 653 | } // namespace
|
|---|
| 654 |
|
|---|
| 655 | void translateThrows( ast::TranslationUnit & transUnit ) {
|
|---|
| 656 | ast::Pass<TranslateThrowsCore>::run( transUnit );
|
|---|
| 657 | }
|
|---|
| 658 |
|
|---|
| 659 | void translateTries( ast::TranslationUnit & transUnit ) {
|
|---|
| 660 | ast::Pass<TryMutatorCore>::run(transUnit);
|
|---|
| 661 | }
|
|---|
| 662 |
|
|---|
| 663 | } // namespace ControlStruct
|
|---|
| 664 |
|
|---|
| 665 | // Local Variables: //
|
|---|
| 666 | // tab-width: 4 //
|
|---|
| 667 | // mode: c++ //
|
|---|
| 668 | // compile-command: "make install" //
|
|---|
| 669 | // End: //
|
|---|