[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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[400b8be] | 28 | typedef std::list<ast::CatchClause*> CatchList; |
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[5f3ba11] | 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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[400b8be] | 47 | void previsit( const ast::CatchClause * stmt ); |
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[5ee153d] | 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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[400b8be] | 90 | void TranslateThrowsCore::previsit( const ast::CatchClause * stmt ) { |
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[5ee153d] | 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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[400b8be] | 149 | const ast::DeclWithType * except_obj, ast::CatchClause * modded_handler ); |
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[5f3ba11] | 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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[e8616b6] | 192 | new ast::BasicType( ast::BasicType::SignedInt ) |
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[5f3ba11] | 193 | ); |
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[33b7d49] | 194 | } |
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| 195 | |
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| 196 | ast::ObjectDecl * TryMutatorCore::make_exception_object( |
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| 197 | CodeLocation const & location ) const { |
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| 198 | assert( except_decl ); |
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| 199 | return new ast::ObjectDecl( |
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| 200 | location, |
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[5f3ba11] | 201 | "__exception_inst", |
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[e8616b6] | 202 | new ast::PointerType( new ast::StructInstType( except_decl ) ) |
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[5f3ba11] | 203 | ); |
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[33b7d49] | 204 | } |
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| 205 | |
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| 206 | ast::ObjectDecl * TryMutatorCore::make_bool_object( |
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| 207 | CodeLocation const & location ) const { |
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| 208 | return new ast::ObjectDecl( |
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| 209 | location, |
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[5f3ba11] | 210 | "__ret_bool", |
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| 211 | new ast::BasicType( ast::BasicType::Bool ), |
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| 212 | nullptr, //init |
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| 213 | ast::Storage::Classes{}, |
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| 214 | ast::Linkage::Cforall, |
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| 215 | nullptr, //width |
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| 216 | std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) } |
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| 217 | ); |
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[33b7d49] | 218 | } |
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| 219 | |
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| 220 | ast::ObjectDecl * TryMutatorCore::make_voidptr_object( |
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| 221 | CodeLocation const & location ) const { |
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| 222 | return new ast::ObjectDecl( |
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| 223 | location, |
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[5f3ba11] | 224 | "__hook", |
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| 225 | new ast::PointerType( |
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| 226 | new ast::VoidType() |
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| 227 | ), |
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| 228 | nullptr, //init |
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| 229 | ast::Storage::Classes{}, |
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| 230 | ast::Linkage::Cforall, |
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| 231 | nullptr, //width |
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| 232 | std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) } |
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| 233 | ); |
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[33b7d49] | 234 | } |
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[5f3ba11] | 235 | |
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[33b7d49] | 236 | ast::ObjectDecl * TryMutatorCore::make_unused_index_object( |
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| 237 | CodeLocation const & location ) const { |
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| 238 | return new ast::ObjectDecl( |
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| 239 | location, |
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[5f3ba11] | 240 | "__handler_index", |
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| 241 | new ast::BasicType(ast::BasicType::SignedInt), |
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| 242 | nullptr, |
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| 243 | ast::Storage::Classes{}, |
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| 244 | ast::Linkage::Cforall, |
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| 245 | nullptr, //width |
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| 246 | std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) } |
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| 247 | ); |
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[33b7d49] | 248 | } |
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[5f3ba11] | 249 | |
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[33b7d49] | 250 | ast::FunctionDecl * TryMutatorCore::make_try_function( |
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| 251 | CodeLocation const & location ) const { |
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| 252 | return new ast::FunctionDecl( |
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| 253 | location, |
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[5f3ba11] | 254 | "try", |
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| 255 | {}, //forall |
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| 256 | {}, //no param |
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| 257 | {}, //no return |
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| 258 | nullptr, |
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| 259 | ast::Storage::Classes{}, |
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| 260 | ast::Linkage::Cforall |
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| 261 | ); |
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[33b7d49] | 262 | } |
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[5f3ba11] | 263 | |
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[33b7d49] | 264 | ast::FunctionDecl * TryMutatorCore::make_catch_function( |
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| 265 | CodeLocation const & location ) const { |
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| 266 | return new ast::FunctionDecl( |
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| 267 | location, |
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[5f3ba11] | 268 | "catch", |
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| 269 | {}, //forall |
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[33b7d49] | 270 | { make_index_object( location ), make_exception_object( location ) }, |
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[5f3ba11] | 271 | {}, //return void |
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| 272 | nullptr, |
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| 273 | ast::Storage::Classes{}, |
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| 274 | ast::Linkage::Cforall |
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| 275 | ); |
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[33b7d49] | 276 | } |
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[5f3ba11] | 277 | |
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[33b7d49] | 278 | ast::FunctionDecl * TryMutatorCore::make_match_function( |
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| 279 | CodeLocation const & location ) const { |
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| 280 | return new ast::FunctionDecl( |
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| 281 | location, |
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[5f3ba11] | 282 | "match", |
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| 283 | {}, //forall |
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[33b7d49] | 284 | { make_exception_object( location ) }, |
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| 285 | { make_unused_index_object( location ) }, |
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[5f3ba11] | 286 | nullptr, |
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| 287 | ast::Storage::Classes{}, |
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| 288 | ast::Linkage::Cforall |
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| 289 | ); |
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[33b7d49] | 290 | } |
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[5f3ba11] | 291 | |
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[33b7d49] | 292 | ast::FunctionDecl * TryMutatorCore::make_handle_function( |
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| 293 | CodeLocation const & location ) const { |
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| 294 | return new ast::FunctionDecl( |
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| 295 | location, |
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[5f3ba11] | 296 | "handle", |
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| 297 | {}, //forall |
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[33b7d49] | 298 | { make_exception_object( location ) }, |
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| 299 | { make_bool_object( location ) }, |
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[5f3ba11] | 300 | nullptr, |
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| 301 | ast::Storage::Classes{}, |
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| 302 | ast::Linkage::Cforall |
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| 303 | ); |
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[33b7d49] | 304 | } |
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[5f3ba11] | 305 | |
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[33b7d49] | 306 | ast::FunctionDecl * TryMutatorCore::make_finally_function( |
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| 307 | CodeLocation const & location ) const { |
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| 308 | return new ast::FunctionDecl( |
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| 309 | location, |
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[5f3ba11] | 310 | "finally", |
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| 311 | {}, //forall |
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[33b7d49] | 312 | { make_voidptr_object( location ) }, |
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[5f3ba11] | 313 | {}, //return void |
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| 314 | nullptr, |
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| 315 | ast::Storage::Classes{}, |
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| 316 | ast::Linkage::Cforall |
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| 317 | ); |
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| 318 | } |
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| 319 | |
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| 320 | // TryStmt Mutation Helpers |
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| 321 | |
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| 322 | ast::FunctionDecl * TryMutatorCore::create_try_wrapper( |
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| 323 | const ast::CompoundStmt *body ) { |
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| 324 | |
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[33b7d49] | 325 | ast::FunctionDecl * ret = make_try_function( body->location ); |
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[5f3ba11] | 326 | ret->stmts = body; |
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| 327 | return ret; |
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| 328 | } |
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| 329 | |
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| 330 | ast::FunctionDecl * TryMutatorCore::create_terminate_catch( |
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| 331 | CatchList &handlers ) { |
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[400b8be] | 332 | std::vector<ast::ptr<ast::CaseClause>> handler_wrappers; |
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[5f3ba11] | 333 | |
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| 334 | assert (!handlers.empty()); |
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| 335 | const CodeLocation loc = handlers.front()->location; |
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| 336 | |
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[33b7d49] | 337 | ast::FunctionDecl * func_t = make_catch_function( loc ); |
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[5f3ba11] | 338 | const ast::DeclWithType * index_obj = func_t->params.front(); |
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| 339 | const ast::DeclWithType * except_obj = func_t->params.back(); |
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| 340 | |
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| 341 | // Index 1..{number of handlers} |
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| 342 | int index = 0; |
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| 343 | CatchList::iterator it = handlers.begin(); |
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| 344 | for ( ; it != handlers.end() ; ++it ) { |
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| 345 | ++index; |
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[400b8be] | 346 | ast::CatchClause * handler = *it; |
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[5f3ba11] | 347 | const CodeLocation loc = handler->location; |
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| 348 | |
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| 349 | // case `index`: |
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| 350 | // { |
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| 351 | // `handler.decl` = { (virtual `decl.type`)`except` }; |
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| 352 | // `handler.body`; |
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| 353 | // } |
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| 354 | // return; |
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| 355 | ast::CompoundStmt * block = new ast::CompoundStmt(loc); |
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| 356 | |
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| 357 | // Just copy the exception value. (Post Validation) |
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| 358 | const ast::ObjectDecl * handler_decl = |
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| 359 | handler->decl.strict_as<ast::ObjectDecl>(); |
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| 360 | ast::ObjectDecl * local_except = ast::deepCopy(handler_decl); |
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| 361 | ast::VirtualCastExpr * vcex = new ast::VirtualCastExpr(loc, |
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| 362 | new ast::VariableExpr( loc, except_obj ), |
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| 363 | local_except->get_type() |
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| 364 | ); |
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| 365 | vcex->location = handler->location; |
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| 366 | local_except->init = new ast::ListInit(loc, { new ast::SingleInit( loc, vcex ) }); |
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| 367 | block->push_back( new ast::DeclStmt( loc, local_except ) ); |
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| 368 | |
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| 369 | // Add the cleanup attribute. |
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| 370 | local_except->attributes.push_back( new ast::Attribute( |
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| 371 | "cleanup", |
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| 372 | { new ast::NameExpr( loc, "__cfaehm_cleanup_terminate" ) } |
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| 373 | ) ); |
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| 374 | |
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| 375 | ast::DeclReplacer::DeclMap mapping; |
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| 376 | mapping[handler_decl] = local_except; |
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| 377 | const ast::Stmt * mutBody = strict_dynamic_cast<const ast::Stmt *>( |
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| 378 | ast::DeclReplacer::replace(handler->body, mapping)); |
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| 379 | |
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| 380 | |
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| 381 | block->push_back( mutBody ); |
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| 382 | // handler->body = nullptr; |
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| 383 | |
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[400b8be] | 384 | handler_wrappers.push_back( new ast::CaseClause(loc, |
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[5f3ba11] | 385 | ast::ConstantExpr::from_int(loc, index) , |
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| 386 | { block, new ast::ReturnStmt( loc, nullptr ) } |
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| 387 | )); |
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| 388 | } |
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| 389 | // TODO: Some sort of meaningful error on default perhaps? |
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| 390 | |
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[33b7d49] | 391 | ast::SwitchStmt * handler_lookup = new ast::SwitchStmt( loc, |
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[5f3ba11] | 392 | new ast::VariableExpr( loc, index_obj ), |
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| 393 | std::move(handler_wrappers) |
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| 394 | ); |
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[33b7d49] | 395 | ast::CompoundStmt * body = new ast::CompoundStmt( loc, {handler_lookup} ); |
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[5f3ba11] | 396 | |
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| 397 | func_t->stmts = body; |
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| 398 | return func_t; |
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| 399 | } |
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| 400 | |
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| 401 | // Create a single check from a moddified handler. |
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| 402 | // except_obj is referenced, modded_handler will be freed. |
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| 403 | ast::CompoundStmt * TryMutatorCore::create_single_matcher( |
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[400b8be] | 404 | const ast::DeclWithType * except_obj, ast::CatchClause * modded_handler ) { |
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[5f3ba11] | 405 | // { |
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| 406 | // `modded_handler.decl` |
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| 407 | // if ( `decl.name = (virtual `decl.type`)`except` |
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| 408 | // [&& `modded_handler.cond`] ) { |
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| 409 | // `modded_handler.body` |
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| 410 | // } |
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| 411 | // } |
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| 412 | |
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| 413 | const CodeLocation loc = modded_handler->location; |
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| 414 | ast::CompoundStmt * block = new ast::CompoundStmt(loc); |
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| 415 | |
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| 416 | // Local Declaration |
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| 417 | const ast::ObjectDecl * local_except = |
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| 418 | modded_handler->decl.strict_as<ast::ObjectDecl>(); |
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| 419 | block->push_back( new ast::DeclStmt( loc, local_except ) ); |
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| 420 | |
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| 421 | // Check for type match. |
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[33b7d49] | 422 | ast::VirtualCastExpr * vcex = new ast::VirtualCastExpr(loc, |
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[5f3ba11] | 423 | new ast::VariableExpr(loc, except_obj ), |
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| 424 | local_except->get_type() |
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| 425 | ); |
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| 426 | ast::Expr * cond = ast::UntypedExpr::createAssign(loc, |
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| 427 | new ast::VariableExpr(loc, local_except ), vcex ); |
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| 428 | |
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| 429 | // Add the check on the conditional if it is provided. |
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| 430 | if ( modded_handler->cond ) { |
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| 431 | cond = new ast::LogicalExpr( loc, cond, modded_handler->cond, ast::LogicalFlag::AndExpr ); |
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| 432 | } |
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| 433 | // Construct the match condition. |
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[33b7d49] | 434 | block->push_back( new ast::IfStmt(loc, |
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[5f3ba11] | 435 | cond, modded_handler->body, nullptr ) ); |
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| 436 | |
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| 437 | return block; |
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| 438 | } |
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| 439 | |
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| 440 | ast::FunctionDecl * TryMutatorCore::create_terminate_match( |
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| 441 | CatchList &handlers ) { |
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| 442 | // int match(exception * except) { |
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| 443 | // HANDLER WRAPPERS { return `index`; } |
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| 444 | // } |
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| 445 | |
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| 446 | assert (!handlers.empty()); |
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| 447 | const CodeLocation loc = handlers.front()->location; |
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| 448 | |
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| 449 | ast::CompoundStmt * body = new ast::CompoundStmt(loc); |
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| 450 | |
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[33b7d49] | 451 | ast::FunctionDecl * func_t = make_match_function( loc ); |
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[5f3ba11] | 452 | const ast::DeclWithType * except_obj = func_t->params.back(); |
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| 453 | |
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| 454 | // Index 1..{number of handlers} |
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| 455 | int index = 0; |
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| 456 | CatchList::iterator it; |
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| 457 | for ( it = handlers.begin() ; it != handlers.end() ; ++it ) { |
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| 458 | ++index; |
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[400b8be] | 459 | ast::CatchClause * handler = *it; |
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[5f3ba11] | 460 | |
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| 461 | // Body should have been taken by create_terminate_catch. |
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| 462 | // xxx - just ignore it? |
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| 463 | // assert( nullptr == handler->get_body() ); |
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| 464 | |
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| 465 | // Create new body. |
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| 466 | handler->body = new ast::ReturnStmt( handler->location, |
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| 467 | ast::ConstantExpr::from_int( handler->location, index ) ); |
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| 468 | |
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| 469 | // Create the handler. |
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| 470 | body->push_back( create_single_matcher( except_obj, handler ) ); |
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| 471 | *it = nullptr; |
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| 472 | } |
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| 473 | |
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[33b7d49] | 474 | body->push_back( new ast::ReturnStmt(loc, |
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[5f3ba11] | 475 | ast::ConstantExpr::from_int( loc, 0 ) )); |
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| 476 | |
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| 477 | func_t->stmts = body; |
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| 478 | |
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| 479 | return func_t; |
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| 480 | } |
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| 481 | |
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| 482 | ast::CompoundStmt * TryMutatorCore::create_terminate_caller( |
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| 483 | CodeLocation loc, |
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| 484 | ast::FunctionDecl * try_wrapper, |
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| 485 | ast::FunctionDecl * terminate_catch, |
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| 486 | ast::FunctionDecl * terminate_match ) { |
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| 487 | // { __cfaehm_try_terminate(`try`, `catch`, `match`); } |
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| 488 | |
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| 489 | ast::UntypedExpr * caller = new ast::UntypedExpr(loc, new ast::NameExpr(loc, |
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| 490 | "__cfaehm_try_terminate" ) ); |
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| 491 | caller->args.push_back( new ast::VariableExpr(loc, try_wrapper ) ); |
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| 492 | caller->args.push_back( new ast::VariableExpr(loc, terminate_catch ) ); |
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| 493 | caller->args.push_back( new ast::VariableExpr(loc, terminate_match ) ); |
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| 494 | |
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| 495 | ast::CompoundStmt * callStmt = new ast::CompoundStmt(loc); |
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| 496 | callStmt->push_back( new ast::ExprStmt( loc, caller ) ); |
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| 497 | return callStmt; |
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| 498 | } |
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| 499 | |
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| 500 | ast::FunctionDecl * TryMutatorCore::create_resume_handler( |
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| 501 | CatchList &handlers ) { |
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| 502 | // bool handle(exception * except) { |
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| 503 | // HANDLER WRAPPERS { `hander->body`; return true; } |
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| 504 | // } |
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| 505 | assert (!handlers.empty()); |
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| 506 | const CodeLocation loc = handlers.front()->location; |
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| 507 | ast::CompoundStmt * body = new ast::CompoundStmt(loc); |
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| 508 | |
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[33b7d49] | 509 | ast::FunctionDecl * func_t = make_handle_function( loc ); |
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[5f3ba11] | 510 | const ast::DeclWithType * except_obj = func_t->params.back(); |
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| 511 | |
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| 512 | CatchList::iterator it; |
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| 513 | for ( it = handlers.begin() ; it != handlers.end() ; ++it ) { |
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[400b8be] | 514 | ast::CatchClause * handler = *it; |
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[5f3ba11] | 515 | const CodeLocation loc = handler->location; |
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| 516 | // Modifiy body. |
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| 517 | ast::CompoundStmt * handling_code; |
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| 518 | if (handler->body.as<ast::CompoundStmt>()) { |
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[33b7d49] | 519 | handling_code = strict_dynamic_cast<ast::CompoundStmt*>( |
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| 520 | handler->body.get_and_mutate() ); |
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[5f3ba11] | 521 | } else { |
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| 522 | handling_code = new ast::CompoundStmt(loc); |
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| 523 | handling_code->push_back( handler->body ); |
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| 524 | } |
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| 525 | handling_code->push_back( new ast::ReturnStmt(loc, |
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| 526 | ast::ConstantExpr::from_bool(loc, true ) ) ); |
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| 527 | handler->body = handling_code; |
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| 528 | |
---|
| 529 | // Create the handler. |
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| 530 | body->push_back( create_single_matcher( except_obj, handler ) ); |
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| 531 | *it = nullptr; |
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| 532 | } |
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| 533 | |
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| 534 | body->push_back( new ast::ReturnStmt(loc, |
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| 535 | ast::ConstantExpr::from_bool(loc, false ) ) ); |
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| 536 | func_t->stmts = body; |
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| 537 | |
---|
| 538 | return func_t; |
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| 539 | } |
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| 540 | |
---|
| 541 | ast::CompoundStmt * TryMutatorCore::create_resume_wrapper( |
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| 542 | const ast::Stmt * wraps, |
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| 543 | const ast::FunctionDecl * resume_handler ) { |
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| 544 | const CodeLocation loc = wraps->location; |
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| 545 | ast::CompoundStmt * body = new ast::CompoundStmt(loc); |
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| 546 | |
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| 547 | // struct __try_resume_node __resume_node |
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| 548 | // __attribute__((cleanup( __cfaehm_try_resume_cleanup ))); |
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| 549 | // ** unwinding of the stack here could cause problems ** |
---|
| 550 | // ** however I don't think that can happen currently ** |
---|
| 551 | // __cfaehm_try_resume_setup( &__resume_node, resume_handler ); |
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| 552 | |
---|
| 553 | ast::ObjectDecl * obj = new ast::ObjectDecl( |
---|
| 554 | loc, |
---|
| 555 | "__resume_node", |
---|
| 556 | new ast::StructInstType( |
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| 557 | node_decl |
---|
| 558 | ), |
---|
| 559 | nullptr, |
---|
| 560 | ast::Storage::Classes{}, |
---|
| 561 | ast::Linkage::Cforall, |
---|
| 562 | nullptr, |
---|
| 563 | {new ast::Attribute("cleanup", {new ast::NameExpr(loc, "__cfaehm_try_resume_cleanup")})} |
---|
| 564 | ); |
---|
| 565 | appendDeclStmt( body, obj ); |
---|
| 566 | |
---|
| 567 | ast::UntypedExpr *setup = new ast::UntypedExpr(loc, new ast::NameExpr(loc, |
---|
| 568 | "__cfaehm_try_resume_setup" ) ); |
---|
| 569 | setup->args.push_back( new ast::AddressExpr( loc, new ast::VariableExpr(loc, obj ) ) ); |
---|
| 570 | setup->args.push_back( new ast::VariableExpr( loc, resume_handler ) ); |
---|
| 571 | |
---|
| 572 | body->push_back( new ast::ExprStmt(loc, setup ) ); |
---|
| 573 | |
---|
| 574 | body->push_back( wraps ); |
---|
| 575 | return body; |
---|
| 576 | } |
---|
| 577 | |
---|
| 578 | ast::FunctionDecl * TryMutatorCore::create_finally_wrapper( |
---|
| 579 | ast::TryStmt * tryStmt ) { |
---|
| 580 | // void finally() { `finally->block` } |
---|
[400b8be] | 581 | const ast::FinallyClause * finally = tryStmt->finally; |
---|
[5f3ba11] | 582 | const ast::CompoundStmt * body = finally->body; |
---|
| 583 | |
---|
[33b7d49] | 584 | ast::FunctionDecl * func_t = make_finally_function( tryStmt->location ); |
---|
[5f3ba11] | 585 | func_t->stmts = body; |
---|
| 586 | |
---|
| 587 | tryStmt->finally = nullptr; |
---|
| 588 | |
---|
| 589 | return func_t; |
---|
| 590 | } |
---|
| 591 | |
---|
| 592 | ast::ObjectDecl * TryMutatorCore::create_finally_hook( |
---|
| 593 | ast::FunctionDecl * finally_wrapper ) { |
---|
| 594 | // struct __cfaehm_cleanup_hook __finally_hook |
---|
| 595 | // __attribute__((cleanup( `finally_wrapper` ))); |
---|
| 596 | |
---|
| 597 | const CodeLocation loc = finally_wrapper->location; |
---|
| 598 | return new ast::ObjectDecl( |
---|
| 599 | loc, |
---|
| 600 | "__finally_hook", |
---|
| 601 | new ast::StructInstType( |
---|
| 602 | hook_decl |
---|
| 603 | ), |
---|
| 604 | nullptr, |
---|
| 605 | ast::Storage::Classes{}, |
---|
| 606 | ast::Linkage::Cforall, |
---|
| 607 | nullptr, |
---|
| 608 | {new ast::Attribute("cleanup", {new ast::VariableExpr{loc, finally_wrapper}})} |
---|
| 609 | ); |
---|
| 610 | } |
---|
| 611 | |
---|
| 612 | ast::Stmt * TryMutatorCore::create_resume_rethrow( const ast::ThrowStmt *throwStmt ) { |
---|
| 613 | // return false; |
---|
| 614 | const CodeLocation loc = throwStmt->location; |
---|
[33b7d49] | 615 | ast::Stmt * result = new ast::ReturnStmt(loc, |
---|
[5f3ba11] | 616 | ast::ConstantExpr::from_bool( loc, false ) |
---|
| 617 | ); |
---|
| 618 | result->labels = throwStmt->labels; |
---|
| 619 | return result; |
---|
| 620 | } |
---|
| 621 | |
---|
| 622 | // Visiting/Mutating Functions |
---|
| 623 | void TryMutatorCore::previsit( const ast::StructDecl *structDecl ) { |
---|
| 624 | if ( !structDecl->body ) { |
---|
| 625 | // Skip children? |
---|
| 626 | return; |
---|
| 627 | } else if ( structDecl->name == "__cfaehm_base_exception_t" ) { |
---|
| 628 | assert( nullptr == except_decl ); |
---|
| 629 | except_decl = structDecl; |
---|
| 630 | } else if ( structDecl->name == "__cfaehm_try_resume_node" ) { |
---|
| 631 | assert( nullptr == node_decl ); |
---|
| 632 | node_decl = structDecl; |
---|
| 633 | } else if ( structDecl->name == "__cfaehm_cleanup_hook" ) { |
---|
| 634 | assert( nullptr == hook_decl ); |
---|
| 635 | hook_decl = structDecl; |
---|
| 636 | } |
---|
| 637 | } |
---|
| 638 | |
---|
| 639 | ast::Stmt * TryMutatorCore::postvisit( const ast::TryStmt *tryStmt ) { |
---|
| 640 | assert( except_decl ); |
---|
| 641 | assert( node_decl ); |
---|
| 642 | assert( hook_decl ); |
---|
| 643 | |
---|
| 644 | const CodeLocation loc = tryStmt->location; |
---|
| 645 | ast::TryStmt * mutStmt = mutate(tryStmt); |
---|
| 646 | // Generate a prefix for the function names? |
---|
| 647 | |
---|
| 648 | ast::CompoundStmt * block = new ast::CompoundStmt( loc ); |
---|
| 649 | // ast::CompoundStmt * inner = take_try_block( mutStmt ); |
---|
| 650 | // this is never mutated so let node deletion do its job? |
---|
| 651 | const ast::CompoundStmt * inner = mutStmt->body; |
---|
| 652 | |
---|
| 653 | if ( mutStmt->finally ) { |
---|
| 654 | // Define the helper function. |
---|
| 655 | ast::FunctionDecl * finally_block = |
---|
| 656 | create_finally_wrapper( mutStmt ); |
---|
| 657 | appendDeclStmt( block, finally_block ); |
---|
| 658 | // Create and add the finally cleanup hook. |
---|
| 659 | appendDeclStmt( block, create_finally_hook( finally_block ) ); |
---|
| 660 | } |
---|
| 661 | |
---|
| 662 | CatchList termination_handlers; |
---|
| 663 | CatchList resumption_handlers; |
---|
| 664 | |
---|
| 665 | for (auto & handler: mutStmt->handlers) { |
---|
| 666 | // xxx - should always be unique? mutate as safe const-cast |
---|
| 667 | assert(handler->unique()); |
---|
| 668 | if (handler->kind == ast::ExceptionKind::Resume) { |
---|
| 669 | resumption_handlers.push_back(handler.get_and_mutate()); |
---|
| 670 | } |
---|
| 671 | else { |
---|
| 672 | termination_handlers.push_back(handler.get_and_mutate()); |
---|
| 673 | } |
---|
| 674 | } |
---|
| 675 | |
---|
| 676 | if ( resumption_handlers.size() ) { |
---|
| 677 | // Define the helper function. |
---|
| 678 | ast::FunctionDecl * resume_handler = |
---|
| 679 | create_resume_handler( resumption_handlers ); |
---|
| 680 | appendDeclStmt( block, resume_handler ); |
---|
| 681 | // Prepare hooks |
---|
| 682 | inner = create_resume_wrapper( inner, resume_handler ); |
---|
| 683 | } |
---|
| 684 | |
---|
| 685 | if ( termination_handlers.size() ) { |
---|
| 686 | // Define the three helper functions. |
---|
| 687 | ast::FunctionDecl * try_wrapper = create_try_wrapper( inner ); |
---|
| 688 | appendDeclStmt( block, try_wrapper ); |
---|
| 689 | ast::FunctionDecl * terminate_catch = |
---|
| 690 | create_terminate_catch( termination_handlers ); |
---|
| 691 | appendDeclStmt( block, terminate_catch ); |
---|
| 692 | ast::FunctionDecl * terminate_match = |
---|
| 693 | create_terminate_match( termination_handlers ); |
---|
| 694 | appendDeclStmt( block, terminate_match ); |
---|
| 695 | // Build the call to the try wrapper. |
---|
| 696 | inner = create_terminate_caller(inner->location, |
---|
| 697 | try_wrapper, terminate_catch, terminate_match ); |
---|
| 698 | } |
---|
| 699 | |
---|
| 700 | // Embed the try block. |
---|
| 701 | block->push_back( inner ); |
---|
| 702 | |
---|
| 703 | return block; |
---|
| 704 | } |
---|
| 705 | |
---|
| 706 | ast::Stmt * TryMutatorCore::postvisit( const ast::ThrowStmt *throwStmt ) { |
---|
| 707 | // Only valid `throwResume;` statements should remain. (2/3 checks) |
---|
| 708 | assert( ast::ExceptionKind::Resume == throwStmt->kind && ! throwStmt->expr ); |
---|
| 709 | return create_resume_rethrow( throwStmt ); |
---|
| 710 | } |
---|
| 711 | |
---|
[5ee153d] | 712 | } // namespace |
---|
| 713 | |
---|
| 714 | void translateThrows( ast::TranslationUnit & transUnit ) { |
---|
| 715 | ast::Pass<TranslateThrowsCore>::run( transUnit ); |
---|
| 716 | } |
---|
| 717 | |
---|
[5f3ba11] | 718 | void translateTries( ast::TranslationUnit & transUnit ) { |
---|
| 719 | ast::Pass<TryMutatorCore>::run(transUnit); |
---|
| 720 | } |
---|
| 721 | |
---|
[5ee153d] | 722 | } // namespace ControlStruct |
---|
| 723 | |
---|
| 724 | // Local Variables: // |
---|
| 725 | // tab-width: 4 // |
---|
| 726 | // mode: c++ // |
---|
| 727 | // compile-command: "make install" // |
---|
| 728 | // End: // |
---|