[5ee153d] | 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 | // ExceptTranslateNew.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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[33b7d49] | 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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[5ee153d] | 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 "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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[5f3ba11] | 22 | #include "AST/DeclReplacer.hpp" |
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[5ee153d] | 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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[5f3ba11] | 28 | typedef std::list<ast::CatchStmt*> 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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[5ee153d] | 34 | class TranslateThrowsCore : 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::CatchStmt * 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::CatchStmt * 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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[5f3ba11] | 137 | |
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| 138 | class TryMutatorCore { |
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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::FunctionDecl * create_terminate_catch( CatchList &handlers ); |
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| 148 | ast::CompoundStmt * create_single_matcher( |
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| 149 | const ast::DeclWithType * except_obj, ast::CatchStmt * modded_handler ); |
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| 150 | ast::FunctionDecl * create_terminate_match( CatchList &handlers ); |
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| 151 | ast::CompoundStmt * create_terminate_caller( CodeLocation loc, ast::FunctionDecl * try_wrapper, |
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| 152 | ast::FunctionDecl * terminate_catch, ast::FunctionDecl * terminate_match ); |
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| 153 | ast::FunctionDecl * create_resume_handler( CatchList &handlers ); |
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| 154 | ast::CompoundStmt * create_resume_wrapper( |
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| 155 | const ast::Stmt * wraps, const ast::FunctionDecl * resume_handler ); |
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| 156 | ast::FunctionDecl * create_finally_wrapper( ast::TryStmt * tryStmt ); |
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| 157 | ast::ObjectDecl * create_finally_hook( ast::FunctionDecl * finally_wrapper ); |
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| 158 | ast::Stmt * create_resume_rethrow( const ast::ThrowStmt * throwStmt ); |
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| 159 | |
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[33b7d49] | 160 | // Types used in translation, first group are internal. |
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| 161 | ast::ObjectDecl * make_index_object( CodeLocation const & ) const; |
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| 162 | ast::ObjectDecl * make_exception_object( CodeLocation const & ) const; |
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| 163 | ast::ObjectDecl * make_bool_object( CodeLocation const & ) const; |
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| 164 | ast::ObjectDecl * make_voidptr_object( CodeLocation const & ) const; |
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| 165 | ast::ObjectDecl * make_unused_index_object( CodeLocation const & ) const; |
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[5f3ba11] | 166 | // void (*function)(); |
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[33b7d49] | 167 | ast::FunctionDecl * make_try_function( CodeLocation const & ) const; |
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[5f3ba11] | 168 | // void (*function)(int, exception); |
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[33b7d49] | 169 | ast::FunctionDecl * make_catch_function( CodeLocation const & ) const; |
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[5f3ba11] | 170 | // int (*function)(exception); |
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[33b7d49] | 171 | ast::FunctionDecl * make_match_function( CodeLocation const & ) const; |
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[5f3ba11] | 172 | // bool (*function)(exception); |
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[33b7d49] | 173 | ast::FunctionDecl * make_handle_function( CodeLocation const & ) const; |
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[5f3ba11] | 174 | // void (*function)(__attribute__((unused)) void *); |
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[33b7d49] | 175 | ast::FunctionDecl * make_finally_function( CodeLocation const & ) const; |
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[5f3ba11] | 176 | |
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| 177 | public: |
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| 178 | TryMutatorCore() : |
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| 179 | except_decl( nullptr ), node_decl( nullptr ), hook_decl( nullptr ) |
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| 180 | {} |
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| 181 | |
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| 182 | void previsit( const ast::StructDecl *structDecl ); |
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| 183 | ast::Stmt * postvisit( const ast::TryStmt *tryStmt ); |
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| 184 | ast::Stmt * postvisit( const ast::ThrowStmt *throwStmt ); |
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| 185 | }; |
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| 186 | |
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[33b7d49] | 187 | ast::ObjectDecl * TryMutatorCore::make_index_object( |
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| 188 | CodeLocation const & location ) const { |
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| 189 | return new ast::ObjectDecl( |
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| 190 | location, |
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[5f3ba11] | 191 | "__handler_index", |
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[33b7d49] | 192 | new ast::BasicType(ast::BasicType::SignedInt), |
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| 193 | nullptr, //init |
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| 194 | ast::Storage::Classes{}, |
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| 195 | ast::Linkage::Cforall |
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[5f3ba11] | 196 | ); |
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[33b7d49] | 197 | } |
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| 198 | |
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| 199 | ast::ObjectDecl * TryMutatorCore::make_exception_object( |
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| 200 | CodeLocation const & location ) const { |
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| 201 | assert( except_decl ); |
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| 202 | return new ast::ObjectDecl( |
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| 203 | location, |
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[5f3ba11] | 204 | "__exception_inst", |
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| 205 | new ast::PointerType( |
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| 206 | new ast::StructInstType( except_decl ) |
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| 207 | ), |
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[33b7d49] | 208 | nullptr, //init |
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| 209 | ast::Storage::Classes{}, |
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| 210 | ast::Linkage::Cforall |
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[5f3ba11] | 211 | ); |
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[33b7d49] | 212 | } |
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| 213 | |
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| 214 | ast::ObjectDecl * TryMutatorCore::make_bool_object( |
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| 215 | CodeLocation const & location ) const { |
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| 216 | return new ast::ObjectDecl( |
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| 217 | location, |
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[5f3ba11] | 218 | "__ret_bool", |
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| 219 | new ast::BasicType( ast::BasicType::Bool ), |
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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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[33b7d49] | 226 | } |
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| 227 | |
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| 228 | ast::ObjectDecl * TryMutatorCore::make_voidptr_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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[5f3ba11] | 232 | "__hook", |
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| 233 | new ast::PointerType( |
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| 234 | new ast::VoidType() |
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| 235 | ), |
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| 236 | nullptr, //init |
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| 237 | ast::Storage::Classes{}, |
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| 238 | ast::Linkage::Cforall, |
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| 239 | nullptr, //width |
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| 240 | std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) } |
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| 241 | ); |
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[33b7d49] | 242 | } |
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[5f3ba11] | 243 | |
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[33b7d49] | 244 | ast::ObjectDecl * TryMutatorCore::make_unused_index_object( |
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| 245 | CodeLocation const & location ) const { |
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| 246 | return new ast::ObjectDecl( |
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| 247 | location, |
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[5f3ba11] | 248 | "__handler_index", |
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| 249 | new ast::BasicType(ast::BasicType::SignedInt), |
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| 250 | nullptr, |
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| 251 | ast::Storage::Classes{}, |
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| 252 | ast::Linkage::Cforall, |
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| 253 | nullptr, //width |
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| 254 | std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) } |
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| 255 | ); |
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[33b7d49] | 256 | } |
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[5f3ba11] | 257 | |
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[33b7d49] | 258 | ast::FunctionDecl * TryMutatorCore::make_try_function( |
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| 259 | CodeLocation const & location ) const { |
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| 260 | return new ast::FunctionDecl( |
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| 261 | location, |
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[5f3ba11] | 262 | "try", |
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| 263 | {}, //forall |
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| 264 | {}, //no param |
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| 265 | {}, //no return |
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| 266 | nullptr, |
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| 267 | ast::Storage::Classes{}, |
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| 268 | ast::Linkage::Cforall |
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| 269 | ); |
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[33b7d49] | 270 | } |
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[5f3ba11] | 271 | |
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[33b7d49] | 272 | ast::FunctionDecl * TryMutatorCore::make_catch_function( |
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| 273 | CodeLocation const & location ) const { |
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| 274 | return new ast::FunctionDecl( |
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| 275 | location, |
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[5f3ba11] | 276 | "catch", |
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| 277 | {}, //forall |
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[33b7d49] | 278 | { make_index_object( location ), make_exception_object( location ) }, |
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[5f3ba11] | 279 | {}, //return void |
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| 280 | nullptr, |
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| 281 | ast::Storage::Classes{}, |
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| 282 | ast::Linkage::Cforall |
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| 283 | ); |
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[33b7d49] | 284 | } |
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[5f3ba11] | 285 | |
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[33b7d49] | 286 | ast::FunctionDecl * TryMutatorCore::make_match_function( |
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| 287 | CodeLocation const & location ) const { |
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| 288 | return new ast::FunctionDecl( |
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| 289 | location, |
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[5f3ba11] | 290 | "match", |
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| 291 | {}, //forall |
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[33b7d49] | 292 | { make_exception_object( location ) }, |
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| 293 | { make_unused_index_object( location ) }, |
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[5f3ba11] | 294 | nullptr, |
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| 295 | ast::Storage::Classes{}, |
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| 296 | ast::Linkage::Cforall |
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| 297 | ); |
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[33b7d49] | 298 | } |
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[5f3ba11] | 299 | |
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[33b7d49] | 300 | ast::FunctionDecl * TryMutatorCore::make_handle_function( |
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| 301 | CodeLocation const & location ) const { |
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| 302 | return new ast::FunctionDecl( |
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| 303 | location, |
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[5f3ba11] | 304 | "handle", |
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| 305 | {}, //forall |
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[33b7d49] | 306 | { make_exception_object( location ) }, |
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| 307 | { make_bool_object( location ) }, |
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[5f3ba11] | 308 | nullptr, |
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| 309 | ast::Storage::Classes{}, |
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| 310 | ast::Linkage::Cforall |
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| 311 | ); |
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[33b7d49] | 312 | } |
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[5f3ba11] | 313 | |
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[33b7d49] | 314 | ast::FunctionDecl * TryMutatorCore::make_finally_function( |
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| 315 | CodeLocation const & location ) const { |
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| 316 | return new ast::FunctionDecl( |
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| 317 | location, |
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[5f3ba11] | 318 | "finally", |
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| 319 | {}, //forall |
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[33b7d49] | 320 | { make_voidptr_object( location ) }, |
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[5f3ba11] | 321 | {}, //return void |
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| 322 | nullptr, |
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| 323 | ast::Storage::Classes{}, |
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| 324 | ast::Linkage::Cforall |
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| 325 | ); |
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| 326 | } |
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| 327 | |
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| 328 | // TryStmt Mutation Helpers |
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| 329 | |
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| 330 | ast::FunctionDecl * TryMutatorCore::create_try_wrapper( |
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| 331 | const ast::CompoundStmt *body ) { |
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| 332 | |
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[33b7d49] | 333 | ast::FunctionDecl * ret = make_try_function( body->location ); |
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[5f3ba11] | 334 | ret->stmts = body; |
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| 335 | return ret; |
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| 336 | } |
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| 337 | |
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| 338 | ast::FunctionDecl * TryMutatorCore::create_terminate_catch( |
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| 339 | CatchList &handlers ) { |
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| 340 | std::vector<ast::ptr<ast::Stmt>> handler_wrappers; |
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| 341 | |
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| 342 | assert (!handlers.empty()); |
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| 343 | const CodeLocation loc = handlers.front()->location; |
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| 344 | |
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[33b7d49] | 345 | ast::FunctionDecl * func_t = make_catch_function( loc ); |
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[5f3ba11] | 346 | const ast::DeclWithType * index_obj = func_t->params.front(); |
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| 347 | const ast::DeclWithType * except_obj = func_t->params.back(); |
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| 348 | |
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| 349 | // Index 1..{number of handlers} |
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| 350 | int index = 0; |
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| 351 | CatchList::iterator it = handlers.begin(); |
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| 352 | for ( ; it != handlers.end() ; ++it ) { |
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| 353 | ++index; |
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| 354 | ast::CatchStmt * handler = *it; |
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| 355 | const CodeLocation loc = handler->location; |
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| 356 | |
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| 357 | // case `index`: |
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| 358 | // { |
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| 359 | // `handler.decl` = { (virtual `decl.type`)`except` }; |
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| 360 | // `handler.body`; |
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| 361 | // } |
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| 362 | // return; |
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| 363 | ast::CompoundStmt * block = new ast::CompoundStmt(loc); |
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| 364 | |
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| 365 | // Just copy the exception value. (Post Validation) |
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| 366 | const ast::ObjectDecl * handler_decl = |
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| 367 | handler->decl.strict_as<ast::ObjectDecl>(); |
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| 368 | ast::ObjectDecl * local_except = ast::deepCopy(handler_decl); |
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| 369 | ast::VirtualCastExpr * vcex = new ast::VirtualCastExpr(loc, |
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| 370 | new ast::VariableExpr( loc, except_obj ), |
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| 371 | local_except->get_type() |
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| 372 | ); |
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| 373 | vcex->location = handler->location; |
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| 374 | local_except->init = new ast::ListInit(loc, { new ast::SingleInit( loc, vcex ) }); |
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| 375 | block->push_back( new ast::DeclStmt( loc, local_except ) ); |
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| 376 | |
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| 377 | // Add the cleanup attribute. |
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| 378 | local_except->attributes.push_back( new ast::Attribute( |
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| 379 | "cleanup", |
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| 380 | { new ast::NameExpr( loc, "__cfaehm_cleanup_terminate" ) } |
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| 381 | ) ); |
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| 382 | |
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| 383 | ast::DeclReplacer::DeclMap mapping; |
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| 384 | mapping[handler_decl] = local_except; |
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| 385 | const ast::Stmt * mutBody = strict_dynamic_cast<const ast::Stmt *>( |
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| 386 | ast::DeclReplacer::replace(handler->body, mapping)); |
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| 387 | |
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| 388 | |
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| 389 | block->push_back( mutBody ); |
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| 390 | // handler->body = nullptr; |
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| 391 | |
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[33b7d49] | 392 | handler_wrappers.push_back( new ast::CaseStmt(loc, |
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[5f3ba11] | 393 | ast::ConstantExpr::from_int(loc, index) , |
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| 394 | { block, new ast::ReturnStmt( loc, nullptr ) } |
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| 395 | )); |
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| 396 | } |
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| 397 | // TODO: Some sort of meaningful error on default perhaps? |
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| 398 | |
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[33b7d49] | 399 | ast::SwitchStmt * handler_lookup = new ast::SwitchStmt( loc, |
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[5f3ba11] | 400 | new ast::VariableExpr( loc, index_obj ), |
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| 401 | std::move(handler_wrappers) |
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| 402 | ); |
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[33b7d49] | 403 | ast::CompoundStmt * body = new ast::CompoundStmt( loc, {handler_lookup} ); |
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[5f3ba11] | 404 | |
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| 405 | func_t->stmts = body; |
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| 406 | return func_t; |
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| 407 | } |
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| 408 | |
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| 409 | // Create a single check from a moddified handler. |
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| 410 | // except_obj is referenced, modded_handler will be freed. |
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| 411 | ast::CompoundStmt * TryMutatorCore::create_single_matcher( |
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| 412 | const ast::DeclWithType * except_obj, ast::CatchStmt * modded_handler ) { |
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| 413 | // { |
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| 414 | // `modded_handler.decl` |
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| 415 | // if ( `decl.name = (virtual `decl.type`)`except` |
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| 416 | // [&& `modded_handler.cond`] ) { |
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| 417 | // `modded_handler.body` |
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| 418 | // } |
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| 419 | // } |
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| 420 | |
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| 421 | const CodeLocation loc = modded_handler->location; |
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| 422 | ast::CompoundStmt * block = new ast::CompoundStmt(loc); |
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| 423 | |
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| 424 | // Local Declaration |
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| 425 | const ast::ObjectDecl * local_except = |
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| 426 | modded_handler->decl.strict_as<ast::ObjectDecl>(); |
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| 427 | block->push_back( new ast::DeclStmt( loc, local_except ) ); |
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| 428 | |
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| 429 | // Check for type match. |
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[33b7d49] | 430 | ast::VirtualCastExpr * vcex = new ast::VirtualCastExpr(loc, |
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[5f3ba11] | 431 | new ast::VariableExpr(loc, except_obj ), |
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| 432 | local_except->get_type() |
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| 433 | ); |
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| 434 | ast::Expr * cond = ast::UntypedExpr::createAssign(loc, |
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| 435 | new ast::VariableExpr(loc, local_except ), vcex ); |
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| 436 | |
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| 437 | // Add the check on the conditional if it is provided. |
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| 438 | if ( modded_handler->cond ) { |
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| 439 | cond = new ast::LogicalExpr( loc, cond, modded_handler->cond, ast::LogicalFlag::AndExpr ); |
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| 440 | } |
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| 441 | // Construct the match condition. |
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[33b7d49] | 442 | block->push_back( new ast::IfStmt(loc, |
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[5f3ba11] | 443 | cond, modded_handler->body, nullptr ) ); |
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| 444 | |
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| 445 | return block; |
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| 446 | } |
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| 447 | |
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| 448 | ast::FunctionDecl * TryMutatorCore::create_terminate_match( |
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| 449 | CatchList &handlers ) { |
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| 450 | // int match(exception * except) { |
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| 451 | // HANDLER WRAPPERS { return `index`; } |
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| 452 | // } |
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| 453 | |
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| 454 | assert (!handlers.empty()); |
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| 455 | const CodeLocation loc = handlers.front()->location; |
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| 456 | |
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| 457 | ast::CompoundStmt * body = new ast::CompoundStmt(loc); |
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| 458 | |
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[33b7d49] | 459 | ast::FunctionDecl * func_t = make_match_function( loc ); |
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[5f3ba11] | 460 | const ast::DeclWithType * except_obj = func_t->params.back(); |
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| 461 | |
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| 462 | // Index 1..{number of handlers} |
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| 463 | int index = 0; |
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| 464 | CatchList::iterator it; |
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| 465 | for ( it = handlers.begin() ; it != handlers.end() ; ++it ) { |
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| 466 | ++index; |
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| 467 | ast::CatchStmt * handler = *it; |
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| 468 | |
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| 469 | // Body should have been taken by create_terminate_catch. |
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| 470 | // xxx - just ignore it? |
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| 471 | // assert( nullptr == handler->get_body() ); |
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| 472 | |
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| 473 | // Create new body. |
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| 474 | handler->body = new ast::ReturnStmt( handler->location, |
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| 475 | ast::ConstantExpr::from_int( handler->location, index ) ); |
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| 476 | |
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| 477 | // Create the handler. |
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| 478 | body->push_back( create_single_matcher( except_obj, handler ) ); |
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| 479 | *it = nullptr; |
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| 480 | } |
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| 481 | |
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[33b7d49] | 482 | body->push_back( new ast::ReturnStmt(loc, |
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[5f3ba11] | 483 | ast::ConstantExpr::from_int( loc, 0 ) )); |
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| 484 | |
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| 485 | func_t->stmts = body; |
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| 486 | |
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| 487 | return func_t; |
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| 488 | } |
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| 489 | |
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| 490 | ast::CompoundStmt * TryMutatorCore::create_terminate_caller( |
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| 491 | CodeLocation loc, |
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| 492 | ast::FunctionDecl * try_wrapper, |
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| 493 | ast::FunctionDecl * terminate_catch, |
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| 494 | ast::FunctionDecl * terminate_match ) { |
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| 495 | // { __cfaehm_try_terminate(`try`, `catch`, `match`); } |
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| 496 | |
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| 497 | ast::UntypedExpr * caller = new ast::UntypedExpr(loc, new ast::NameExpr(loc, |
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| 498 | "__cfaehm_try_terminate" ) ); |
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| 499 | caller->args.push_back( new ast::VariableExpr(loc, try_wrapper ) ); |
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| 500 | caller->args.push_back( new ast::VariableExpr(loc, terminate_catch ) ); |
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| 501 | caller->args.push_back( new ast::VariableExpr(loc, terminate_match ) ); |
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| 502 | |
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| 503 | ast::CompoundStmt * callStmt = new ast::CompoundStmt(loc); |
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| 504 | callStmt->push_back( new ast::ExprStmt( loc, caller ) ); |
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| 505 | return callStmt; |
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| 506 | } |
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| 507 | |
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| 508 | ast::FunctionDecl * TryMutatorCore::create_resume_handler( |
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| 509 | CatchList &handlers ) { |
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| 510 | // bool handle(exception * except) { |
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| 511 | // HANDLER WRAPPERS { `hander->body`; return true; } |
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| 512 | // } |
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| 513 | assert (!handlers.empty()); |
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| 514 | const CodeLocation loc = handlers.front()->location; |
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| 515 | ast::CompoundStmt * body = new ast::CompoundStmt(loc); |
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| 516 | |
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[33b7d49] | 517 | ast::FunctionDecl * func_t = make_handle_function( loc ); |
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[5f3ba11] | 518 | const ast::DeclWithType * except_obj = func_t->params.back(); |
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| 519 | |
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| 520 | CatchList::iterator it; |
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| 521 | for ( it = handlers.begin() ; it != handlers.end() ; ++it ) { |
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| 522 | ast::CatchStmt * handler = *it; |
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| 523 | const CodeLocation loc = handler->location; |
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| 524 | // Modifiy body. |
---|
| 525 | ast::CompoundStmt * handling_code; |
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| 526 | if (handler->body.as<ast::CompoundStmt>()) { |
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[33b7d49] | 527 | handling_code = strict_dynamic_cast<ast::CompoundStmt*>( |
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| 528 | handler->body.get_and_mutate() ); |
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[5f3ba11] | 529 | } else { |
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| 530 | handling_code = new ast::CompoundStmt(loc); |
---|
| 531 | handling_code->push_back( handler->body ); |
---|
| 532 | } |
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| 533 | handling_code->push_back( new ast::ReturnStmt(loc, |
---|
| 534 | ast::ConstantExpr::from_bool(loc, true ) ) ); |
---|
| 535 | handler->body = handling_code; |
---|
| 536 | |
---|
| 537 | // Create the handler. |
---|
| 538 | body->push_back( create_single_matcher( except_obj, handler ) ); |
---|
| 539 | *it = nullptr; |
---|
| 540 | } |
---|
| 541 | |
---|
| 542 | body->push_back( new ast::ReturnStmt(loc, |
---|
| 543 | ast::ConstantExpr::from_bool(loc, false ) ) ); |
---|
| 544 | func_t->stmts = body; |
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| 545 | |
---|
| 546 | return func_t; |
---|
| 547 | } |
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| 548 | |
---|
| 549 | ast::CompoundStmt * TryMutatorCore::create_resume_wrapper( |
---|
| 550 | const ast::Stmt * wraps, |
---|
| 551 | const ast::FunctionDecl * resume_handler ) { |
---|
| 552 | const CodeLocation loc = wraps->location; |
---|
| 553 | ast::CompoundStmt * body = new ast::CompoundStmt(loc); |
---|
| 554 | |
---|
| 555 | // struct __try_resume_node __resume_node |
---|
| 556 | // __attribute__((cleanup( __cfaehm_try_resume_cleanup ))); |
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| 557 | // ** unwinding of the stack here could cause problems ** |
---|
| 558 | // ** however I don't think that can happen currently ** |
---|
| 559 | // __cfaehm_try_resume_setup( &__resume_node, resume_handler ); |
---|
| 560 | |
---|
| 561 | ast::ObjectDecl * obj = new ast::ObjectDecl( |
---|
| 562 | loc, |
---|
| 563 | "__resume_node", |
---|
| 564 | new ast::StructInstType( |
---|
| 565 | node_decl |
---|
| 566 | ), |
---|
| 567 | nullptr, |
---|
| 568 | ast::Storage::Classes{}, |
---|
| 569 | ast::Linkage::Cforall, |
---|
| 570 | nullptr, |
---|
| 571 | {new ast::Attribute("cleanup", {new ast::NameExpr(loc, "__cfaehm_try_resume_cleanup")})} |
---|
| 572 | ); |
---|
| 573 | appendDeclStmt( body, obj ); |
---|
| 574 | |
---|
| 575 | ast::UntypedExpr *setup = new ast::UntypedExpr(loc, new ast::NameExpr(loc, |
---|
| 576 | "__cfaehm_try_resume_setup" ) ); |
---|
| 577 | setup->args.push_back( new ast::AddressExpr( loc, new ast::VariableExpr(loc, obj ) ) ); |
---|
| 578 | setup->args.push_back( new ast::VariableExpr( loc, resume_handler ) ); |
---|
| 579 | |
---|
| 580 | body->push_back( new ast::ExprStmt(loc, setup ) ); |
---|
| 581 | |
---|
| 582 | body->push_back( wraps ); |
---|
| 583 | return body; |
---|
| 584 | } |
---|
| 585 | |
---|
| 586 | ast::FunctionDecl * TryMutatorCore::create_finally_wrapper( |
---|
| 587 | ast::TryStmt * tryStmt ) { |
---|
| 588 | // void finally() { `finally->block` } |
---|
| 589 | const ast::FinallyStmt * finally = tryStmt->finally; |
---|
| 590 | const ast::CompoundStmt * body = finally->body; |
---|
| 591 | |
---|
[33b7d49] | 592 | ast::FunctionDecl * func_t = make_finally_function( tryStmt->location ); |
---|
[5f3ba11] | 593 | func_t->stmts = body; |
---|
| 594 | |
---|
| 595 | tryStmt->finally = nullptr; |
---|
| 596 | |
---|
| 597 | return func_t; |
---|
| 598 | } |
---|
| 599 | |
---|
| 600 | ast::ObjectDecl * TryMutatorCore::create_finally_hook( |
---|
| 601 | ast::FunctionDecl * finally_wrapper ) { |
---|
| 602 | // struct __cfaehm_cleanup_hook __finally_hook |
---|
| 603 | // __attribute__((cleanup( `finally_wrapper` ))); |
---|
| 604 | |
---|
| 605 | const CodeLocation loc = finally_wrapper->location; |
---|
| 606 | return new ast::ObjectDecl( |
---|
| 607 | loc, |
---|
| 608 | "__finally_hook", |
---|
| 609 | new ast::StructInstType( |
---|
| 610 | hook_decl |
---|
| 611 | ), |
---|
| 612 | nullptr, |
---|
| 613 | ast::Storage::Classes{}, |
---|
| 614 | ast::Linkage::Cforall, |
---|
| 615 | nullptr, |
---|
| 616 | {new ast::Attribute("cleanup", {new ast::VariableExpr{loc, finally_wrapper}})} |
---|
| 617 | ); |
---|
| 618 | } |
---|
| 619 | |
---|
| 620 | ast::Stmt * TryMutatorCore::create_resume_rethrow( const ast::ThrowStmt *throwStmt ) { |
---|
| 621 | // return false; |
---|
| 622 | const CodeLocation loc = throwStmt->location; |
---|
[33b7d49] | 623 | ast::Stmt * result = new ast::ReturnStmt(loc, |
---|
[5f3ba11] | 624 | ast::ConstantExpr::from_bool( loc, false ) |
---|
| 625 | ); |
---|
| 626 | result->labels = throwStmt->labels; |
---|
| 627 | return result; |
---|
| 628 | } |
---|
| 629 | |
---|
| 630 | // Visiting/Mutating Functions |
---|
| 631 | void TryMutatorCore::previsit( const ast::StructDecl *structDecl ) { |
---|
| 632 | if ( !structDecl->body ) { |
---|
| 633 | // Skip children? |
---|
| 634 | return; |
---|
| 635 | } else if ( structDecl->name == "__cfaehm_base_exception_t" ) { |
---|
| 636 | assert( nullptr == except_decl ); |
---|
| 637 | except_decl = structDecl; |
---|
| 638 | } else if ( structDecl->name == "__cfaehm_try_resume_node" ) { |
---|
| 639 | assert( nullptr == node_decl ); |
---|
| 640 | node_decl = structDecl; |
---|
| 641 | } else if ( structDecl->name == "__cfaehm_cleanup_hook" ) { |
---|
| 642 | assert( nullptr == hook_decl ); |
---|
| 643 | hook_decl = structDecl; |
---|
| 644 | } |
---|
| 645 | } |
---|
| 646 | |
---|
| 647 | ast::Stmt * TryMutatorCore::postvisit( const ast::TryStmt *tryStmt ) { |
---|
| 648 | assert( except_decl ); |
---|
| 649 | assert( node_decl ); |
---|
| 650 | assert( hook_decl ); |
---|
| 651 | |
---|
| 652 | const CodeLocation loc = tryStmt->location; |
---|
| 653 | ast::TryStmt * mutStmt = mutate(tryStmt); |
---|
| 654 | // Generate a prefix for the function names? |
---|
| 655 | |
---|
| 656 | ast::CompoundStmt * block = new ast::CompoundStmt( loc ); |
---|
| 657 | // ast::CompoundStmt * inner = take_try_block( mutStmt ); |
---|
| 658 | // this is never mutated so let node deletion do its job? |
---|
| 659 | const ast::CompoundStmt * inner = mutStmt->body; |
---|
| 660 | |
---|
| 661 | if ( mutStmt->finally ) { |
---|
| 662 | // Define the helper function. |
---|
| 663 | ast::FunctionDecl * finally_block = |
---|
| 664 | create_finally_wrapper( mutStmt ); |
---|
| 665 | appendDeclStmt( block, finally_block ); |
---|
| 666 | // Create and add the finally cleanup hook. |
---|
| 667 | appendDeclStmt( block, create_finally_hook( finally_block ) ); |
---|
| 668 | } |
---|
| 669 | |
---|
| 670 | CatchList termination_handlers; |
---|
| 671 | CatchList resumption_handlers; |
---|
| 672 | |
---|
| 673 | for (auto & handler: mutStmt->handlers) { |
---|
| 674 | // xxx - should always be unique? mutate as safe const-cast |
---|
| 675 | assert(handler->unique()); |
---|
| 676 | if (handler->kind == ast::ExceptionKind::Resume) { |
---|
| 677 | resumption_handlers.push_back(handler.get_and_mutate()); |
---|
| 678 | } |
---|
| 679 | else { |
---|
| 680 | termination_handlers.push_back(handler.get_and_mutate()); |
---|
| 681 | } |
---|
| 682 | } |
---|
| 683 | |
---|
| 684 | if ( resumption_handlers.size() ) { |
---|
| 685 | // Define the helper function. |
---|
| 686 | ast::FunctionDecl * resume_handler = |
---|
| 687 | create_resume_handler( resumption_handlers ); |
---|
| 688 | appendDeclStmt( block, resume_handler ); |
---|
| 689 | // Prepare hooks |
---|
| 690 | inner = create_resume_wrapper( inner, resume_handler ); |
---|
| 691 | } |
---|
| 692 | |
---|
| 693 | if ( termination_handlers.size() ) { |
---|
| 694 | // Define the three helper functions. |
---|
| 695 | ast::FunctionDecl * try_wrapper = create_try_wrapper( inner ); |
---|
| 696 | appendDeclStmt( block, try_wrapper ); |
---|
| 697 | ast::FunctionDecl * terminate_catch = |
---|
| 698 | create_terminate_catch( termination_handlers ); |
---|
| 699 | appendDeclStmt( block, terminate_catch ); |
---|
| 700 | ast::FunctionDecl * terminate_match = |
---|
| 701 | create_terminate_match( termination_handlers ); |
---|
| 702 | appendDeclStmt( block, terminate_match ); |
---|
| 703 | // Build the call to the try wrapper. |
---|
| 704 | inner = create_terminate_caller(inner->location, |
---|
| 705 | try_wrapper, terminate_catch, terminate_match ); |
---|
| 706 | } |
---|
| 707 | |
---|
| 708 | // Embed the try block. |
---|
| 709 | block->push_back( inner ); |
---|
| 710 | |
---|
| 711 | return block; |
---|
| 712 | } |
---|
| 713 | |
---|
| 714 | ast::Stmt * TryMutatorCore::postvisit( const ast::ThrowStmt *throwStmt ) { |
---|
| 715 | // Only valid `throwResume;` statements should remain. (2/3 checks) |
---|
| 716 | assert( ast::ExceptionKind::Resume == throwStmt->kind && ! throwStmt->expr ); |
---|
| 717 | return create_resume_rethrow( throwStmt ); |
---|
| 718 | } |
---|
| 719 | |
---|
[5ee153d] | 720 | } // namespace |
---|
| 721 | |
---|
| 722 | void translateThrows( ast::TranslationUnit & transUnit ) { |
---|
| 723 | ast::Pass<TranslateThrowsCore>::run( transUnit ); |
---|
| 724 | } |
---|
| 725 | |
---|
[5f3ba11] | 726 | void translateTries( ast::TranslationUnit & transUnit ) { |
---|
| 727 | ast::Pass<TryMutatorCore>::run(transUnit); |
---|
| 728 | } |
---|
| 729 | |
---|
[5ee153d] | 730 | } // namespace ControlStruct |
---|
| 731 | |
---|
| 732 | // Local Variables: // |
---|
| 733 | // tab-width: 4 // |
---|
| 734 | // mode: c++ // |
---|
| 735 | // compile-command: "make install" // |
---|
| 736 | // End: // |
---|