| /* $Id: except.h 4537 2013-06-19 06:47:43Z riza $ */ |
| /* |
| * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) |
| * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| #ifndef __PJ_EXCEPTION_H__ |
| #define __PJ_EXCEPTION_H__ |
| |
| /** |
| * @file except.h |
| * @brief Exception Handling in C. |
| */ |
| |
| #include <pj/types.h> |
| #include <pj/compat/setjmp.h> |
| #include <pj/log.h> |
| |
| |
| PJ_BEGIN_DECL |
| |
| |
| /** |
| * @defgroup PJ_EXCEPT Exception Handling |
| * @ingroup PJ_MISC |
| * @{ |
| * |
| * \section pj_except_sample_sec Quick Example |
| * |
| * For the impatient, take a look at some examples: |
| * - @ref page_pjlib_samples_except_c |
| * - @ref page_pjlib_exception_test |
| * |
| * \section pj_except_except Exception Handling |
| * |
| * This module provides exception handling syntactically similar to C++ in |
| * C language. In Win32 systems, it uses Windows Structured Exception |
| * Handling (SEH) if macro PJ_EXCEPTION_USE_WIN32_SEH is non-zero. |
| * Otherwise it will use setjmp() and longjmp(). |
| * |
| * On some platforms where setjmp/longjmp is not available, setjmp/longjmp |
| * implementation is provided. See <pj/compat/setjmp.h> for compatibility. |
| * |
| * The exception handling mechanism is completely thread safe, so the exception |
| * thrown by one thread will not interfere with other thread. |
| * |
| * The exception handling constructs are similar to C++. The blocks will be |
| * constructed similar to the following sample: |
| * |
| * \verbatim |
| #define NO_MEMORY 1 |
| #define SYNTAX_ERROR 2 |
| |
| int sample1() |
| { |
| PJ_USE_EXCEPTION; // declare local exception stack. |
| |
| PJ_TRY { |
| ...// do something.. |
| } |
| PJ_CATCH(NO_MEMORY) { |
| ... // handle exception 1 |
| } |
| PJ_END; |
| } |
| |
| int sample2() |
| { |
| PJ_USE_EXCEPTION; // declare local exception stack. |
| |
| PJ_TRY { |
| ...// do something.. |
| } |
| PJ_CATCH_ANY { |
| if (PJ_GET_EXCEPTION() == NO_MEMORY) |
| ...; // handle no memory situation |
| else if (PJ_GET_EXCEPTION() == SYNTAX_ERROR) |
| ...; // handle syntax error |
| } |
| PJ_END; |
| } |
| \endverbatim |
| * |
| * The above sample uses hard coded exception ID. It is @b strongly |
| * recommended that applications request a unique exception ID instead |
| * of hard coded value like above. |
| * |
| * \section pj_except_reg Exception ID Allocation |
| * |
| * To ensure that exception ID (number) are used consistently and to |
| * prevent ID collisions in an application, it is strongly suggested that |
| * applications allocate an exception ID for each possible exception |
| * type. As a bonus of this process, the application can identify |
| * the name of the exception when the particular exception is thrown. |
| * |
| * Exception ID management are performed with the following APIs: |
| * - #pj_exception_id_alloc(). |
| * - #pj_exception_id_free(). |
| * - #pj_exception_id_name(). |
| * |
| * |
| * PJLIB itself automatically allocates one exception id, i.e. |
| * #PJ_NO_MEMORY_EXCEPTION which is declared in <pj/pool.h>. This exception |
| * ID is raised by default pool policy when it fails to allocate memory. |
| * |
| * CAVEATS: |
| * - unlike C++ exception, the scheme here won't call destructors of local |
| * objects if exception is thrown. Care must be taken when a function |
| * hold some resorce such as pool or mutex etc. |
| * - You CAN NOT make nested exception in one single function without using |
| * a nested PJ_USE_EXCEPTION. Samples: |
| \verbatim |
| void wrong_sample() |
| { |
| PJ_USE_EXCEPTION; |
| |
| PJ_TRY { |
| // Do stuffs |
| ... |
| } |
| PJ_CATCH_ANY { |
| // Do other stuffs |
| .... |
| .. |
| |
| // The following block is WRONG! You MUST declare |
| // PJ_USE_EXCEPTION once again in this block. |
| PJ_TRY { |
| .. |
| } |
| PJ_CATCH_ANY { |
| .. |
| } |
| PJ_END; |
| } |
| PJ_END; |
| } |
| |
| \endverbatim |
| |
| * - You MUST NOT exit the function inside the PJ_TRY block. The correct way |
| * is to return from the function after PJ_END block is executed. |
| * For example, the following code will yield crash not in this code, |
| * but rather in the subsequent execution of PJ_TRY block: |
| \verbatim |
| void wrong_sample() |
| { |
| PJ_USE_EXCEPTION; |
| |
| PJ_TRY { |
| // do some stuffs |
| ... |
| return; <======= DO NOT DO THIS! |
| } |
| PJ_CATCH_ANY { |
| } |
| PJ_END; |
| } |
| \endverbatim |
| |
| * - You can not provide more than PJ_CATCH or PJ_CATCH_ANY nor use PJ_CATCH |
| * and PJ_CATCH_ANY for a single PJ_TRY. |
| * - Exceptions will always be caught by the first handler (unlike C++ where |
| * exception is only caught if the type matches. |
| |
| * \section PJ_EX_KEYWORDS Keywords |
| * |
| * \subsection PJ_THROW PJ_THROW(expression) |
| * Throw an exception. The expression thrown is an integer as the result of |
| * the \a expression. This keyword can be specified anywhere within the |
| * program. |
| * |
| * \subsection PJ_USE_EXCEPTION PJ_USE_EXCEPTION |
| * Specify this in the variable definition section of the function block |
| * (or any blocks) to specify that the block has \a PJ_TRY/PJ_CATCH exception |
| * block. |
| * Actually, this is just a macro to declare local variable which is used to |
| * push the exception state to the exception stack. |
| * Note: you must specify PJ_USE_EXCEPTION as the last statement in the |
| * local variable declarations, since it may evaluate to nothing. |
| * |
| * \subsection PJ_TRY PJ_TRY |
| * The \a PJ_TRY keyword is typically followed by a block. If an exception is |
| * thrown in this block, then the execution will resume to the \a PJ_CATCH |
| * handler. |
| * |
| * \subsection PJ_CATCH PJ_CATCH(expression) |
| * The \a PJ_CATCH is normally followed by a block. This block will be executed |
| * if the exception being thrown is equal to the expression specified in the |
| * \a PJ_CATCH. |
| * |
| * \subsection PJ_CATCH_ANY PJ_CATCH_ANY |
| * The \a PJ_CATCH is normally followed by a block. This block will be executed |
| * if any exception was raised in the TRY block. |
| * |
| * \subsection PJ_END PJ_END |
| * Specify this keyword to mark the end of \a PJ_TRY / \a PJ_CATCH blocks. |
| * |
| * \subsection PJ_GET_EXCEPTION PJ_GET_EXCEPTION(void) |
| * Get the last exception thrown. This macro is normally called inside the |
| * \a PJ_CATCH or \a PJ_CATCH_ANY block, altough it can be used anywhere where |
| * the \a PJ_USE_EXCEPTION definition is in scope. |
| * |
| * |
| * \section pj_except_examples_sec Examples |
| * |
| * For some examples on how to use the exception construct, please see: |
| * - @ref page_pjlib_samples_except_c |
| * - @ref page_pjlib_exception_test |
| */ |
| |
| /** |
| * Allocate a unique exception id. |
| * Applications don't have to allocate a unique exception ID before using |
| * the exception construct. However, by doing so it ensures that there is |
| * no collisions of exception ID. |
| * |
| * As a bonus, when exception number is acquired through this function, |
| * the library can assign name to the exception (only if |
| * PJ_HAS_EXCEPTION_NAMES is enabled (default is yes)) and find out the |
| * exception name when it catches an exception. |
| * |
| * @param name Name to be associated with the exception ID. |
| * @param id Pointer to receive the ID. |
| * |
| * @return PJ_SUCCESS on success or PJ_ETOOMANY if the library |
| * is running out out ids. |
| */ |
| PJ_DECL(pj_status_t) pj_exception_id_alloc(const char *name, |
| pj_exception_id_t *id); |
| |
| /** |
| * Free an exception id. |
| * |
| * @param id The exception ID. |
| * |
| * @return PJ_SUCCESS or the appropriate error code. |
| */ |
| PJ_DECL(pj_status_t) pj_exception_id_free(pj_exception_id_t id); |
| |
| /** |
| * Retrieve name associated with the exception id. |
| * |
| * @param id The exception ID. |
| * |
| * @return The name associated with the specified ID. |
| */ |
| PJ_DECL(const char*) pj_exception_id_name(pj_exception_id_t id); |
| |
| |
| /** @} */ |
| |
| #if defined(PJ_EXCEPTION_USE_WIN32_SEH) && PJ_EXCEPTION_USE_WIN32_SEH != 0 |
| /***************************************************************************** |
| ** |
| ** IMPLEMENTATION OF EXCEPTION USING WINDOWS SEH |
| ** |
| ****************************************************************************/ |
| #define WIN32_LEAN_AND_MEAN |
| #include <windows.h> |
| |
| PJ_IDECL_NO_RETURN(void) |
| pj_throw_exception_(pj_exception_id_t id) PJ_ATTR_NORETURN |
| { |
| RaiseException(id,1,0,NULL); |
| } |
| |
| #define PJ_USE_EXCEPTION |
| #define PJ_TRY __try |
| #define PJ_CATCH(id) __except(GetExceptionCode()==id ? \ |
| EXCEPTION_EXECUTE_HANDLER : \ |
| EXCEPTION_CONTINUE_SEARCH) |
| #define PJ_CATCH_ANY __except(EXCEPTION_EXECUTE_HANDLER) |
| #define PJ_END |
| #define PJ_THROW(id) pj_throw_exception_(id) |
| #define PJ_GET_EXCEPTION() GetExceptionCode() |
| |
| |
| #elif defined(PJ_SYMBIAN) && PJ_SYMBIAN!=0 |
| /***************************************************************************** |
| ** |
| ** IMPLEMENTATION OF EXCEPTION USING SYMBIAN LEAVE/TRAP FRAMEWORK |
| ** |
| ****************************************************************************/ |
| |
| /* To include this file, the source file must be compiled as |
| * C++ code! |
| */ |
| #ifdef __cplusplus |
| |
| class TPjException |
| { |
| public: |
| int code_; |
| }; |
| |
| #define PJ_USE_EXCEPTION |
| #define PJ_TRY try |
| //#define PJ_CATCH(id) |
| #define PJ_CATCH_ANY catch (const TPjException & pj_excp_) |
| #define PJ_END |
| #define PJ_THROW(x_id) do { TPjException e; e.code_=x_id; throw e;} \ |
| while (0) |
| #define PJ_GET_EXCEPTION() pj_excp_.code_ |
| |
| #else |
| |
| #define PJ_USE_EXCEPTION |
| #define PJ_TRY |
| #define PJ_CATCH_ANY if (0) |
| #define PJ_END |
| #define PJ_THROW(x_id) do { PJ_LOG(1,("PJ_THROW"," error code = %d",x_id)); } while (0) |
| #define PJ_GET_EXCEPTION() 0 |
| |
| #endif /* __cplusplus */ |
| |
| #else |
| /***************************************************************************** |
| ** |
| ** IMPLEMENTATION OF EXCEPTION USING GENERIC SETJMP/LONGJMP |
| ** |
| ****************************************************************************/ |
| |
| /** |
| * This structure (which should be invisible to user) manages the TRY handler |
| * stack. |
| */ |
| struct pj_exception_state_t |
| { |
| pj_jmp_buf state; /**< jmp_buf. */ |
| struct pj_exception_state_t *prev; /**< Previous state in the list. */ |
| }; |
| |
| /** |
| * Throw exception. |
| * @param id Exception Id. |
| */ |
| PJ_DECL_NO_RETURN(void) |
| pj_throw_exception_(pj_exception_id_t id) PJ_ATTR_NORETURN; |
| |
| /** |
| * Push exception handler. |
| */ |
| PJ_DECL(void) pj_push_exception_handler_(struct pj_exception_state_t *rec); |
| |
| /** |
| * Pop exception handler. |
| */ |
| PJ_DECL(void) pj_pop_exception_handler_(struct pj_exception_state_t *rec); |
| |
| /** |
| * Declare that the function will use exception. |
| * @hideinitializer |
| */ |
| #define PJ_USE_EXCEPTION struct pj_exception_state_t pj_x_except__; int pj_x_code__ |
| |
| /** |
| * Start exception specification block. |
| * @hideinitializer |
| */ |
| #define PJ_TRY if (1) { \ |
| pj_push_exception_handler_(&pj_x_except__); \ |
| pj_x_code__ = pj_setjmp(pj_x_except__.state); \ |
| if (pj_x_code__ == 0) |
| /** |
| * Catch the specified exception Id. |
| * @param id The exception number to catch. |
| * @hideinitializer |
| */ |
| #define PJ_CATCH(id) else if (pj_x_code__ == (id)) |
| |
| /** |
| * Catch any exception number. |
| * @hideinitializer |
| */ |
| #define PJ_CATCH_ANY else |
| |
| /** |
| * End of exception specification block. |
| * @hideinitializer |
| */ |
| #define PJ_END pj_pop_exception_handler_(&pj_x_except__); \ |
| } else {} |
| |
| /** |
| * Throw exception. |
| * @param exception_id The exception number. |
| * @hideinitializer |
| */ |
| #define PJ_THROW(exception_id) pj_throw_exception_(exception_id) |
| |
| /** |
| * Get current exception. |
| * @return Current exception code. |
| * @hideinitializer |
| */ |
| #define PJ_GET_EXCEPTION() (pj_x_code__) |
| |
| #endif /* PJ_EXCEPTION_USE_WIN32_SEH */ |
| |
| |
| PJ_END_DECL |
| |
| |
| |
| #endif /* __PJ_EXCEPTION_H__ */ |
| |
| |