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Diffstat (limited to 'gdb/common/common-exceptions.h')
| -rw-r--r-- | gdb/common/common-exceptions.h | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/gdb/common/common-exceptions.h b/gdb/common/common-exceptions.h new file mode 100644 index 0000000..5f750c3 --- /dev/null +++ b/gdb/common/common-exceptions.h @@ -0,0 +1,185 @@ +/* Exception (throw catch) mechanism, for GDB, the GNU debugger. + + Copyright (C) 1986-2014 Free Software Foundation, Inc. + + This file is part of GDB. + + 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 3 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, see <http://www.gnu.org/licenses/>. */ + +#ifndef COMMON_EXCEPTIONS_H +#define COMMON_EXCEPTIONS_H + +#include "gdb_setjmp.h" + +/* Reasons for calling throw_exceptions(). NOTE: all reason values + must be less than zero. enum value 0 is reserved for internal use + as the return value from an initial setjmp(). The function + catch_exceptions() reserves values >= 0 as legal results from its + wrapped function. */ + +enum return_reason + { + /* User interrupt. */ + RETURN_QUIT = -2, + /* Any other error. */ + RETURN_ERROR + }; + +#define RETURN_MASK(reason) (1 << (int)(-reason)) + +typedef enum +{ + RETURN_MASK_QUIT = RETURN_MASK (RETURN_QUIT), + RETURN_MASK_ERROR = RETURN_MASK (RETURN_ERROR), + RETURN_MASK_ALL = (RETURN_MASK_QUIT | RETURN_MASK_ERROR) +} return_mask; + +/* Describe all exceptions. */ + +enum errors { + GDB_NO_ERROR, + + /* Any generic error, the corresponding text is in + exception.message. */ + GENERIC_ERROR, + + /* Something requested was not found. */ + NOT_FOUND_ERROR, + + /* Thread library lacks support necessary for finding thread local + storage. */ + TLS_NO_LIBRARY_SUPPORT_ERROR, + + /* Load module not found while attempting to find thread local storage. */ + TLS_LOAD_MODULE_NOT_FOUND_ERROR, + + /* Thread local storage has not been allocated yet. */ + TLS_NOT_ALLOCATED_YET_ERROR, + + /* Something else went wrong while attempting to find thread local + storage. The ``struct gdb_exception'' message field provides + more detail. */ + TLS_GENERIC_ERROR, + + /* Problem parsing an XML document. */ + XML_PARSE_ERROR, + + /* Error accessing memory. */ + MEMORY_ERROR, + + /* Value not available. E.g., a register was not collected in a + traceframe. */ + NOT_AVAILABLE_ERROR, + + /* Value was optimized out. Note: if the value was a register, this + means the register was not saved in the frame. */ + OPTIMIZED_OUT_ERROR, + + /* DW_OP_GNU_entry_value resolving failed. */ + NO_ENTRY_VALUE_ERROR, + + /* Target throwing an error has been closed. Current command should be + aborted as the inferior state is no longer valid. */ + TARGET_CLOSE_ERROR, + + /* An undefined command was executed. */ + UNDEFINED_COMMAND_ERROR, + + /* Requested feature, method, mechanism, etc. is not supported. */ + NOT_SUPPORTED_ERROR, + + /* Add more errors here. */ + NR_ERRORS +}; + +struct gdb_exception +{ + enum return_reason reason; + enum errors error; + const char *message; +}; + +/* Functions to drive the exceptions state machine. Though declared + here by necessity, these functions should be considered internal to + the exceptions subsystem and not used other than via the TRY_CATCH + macro defined below. */ + +extern SIGJMP_BUF *exceptions_state_mc_init (volatile struct + gdb_exception *exception, + return_mask mask); +extern int exceptions_state_mc_action_iter (void); +extern int exceptions_state_mc_action_iter_1 (void); + +/* Macro to wrap up standard try/catch behavior. + + The double loop lets us correctly handle code "break"ing out of the + try catch block. (It works as the "break" only exits the inner + "while" loop, the outer for loop detects this handling it + correctly.) Of course "return" and "goto" are not so lucky. + + For instance: + + *INDENT-OFF* + + volatile struct gdb_exception e; + TRY_CATCH (e, RETURN_MASK_ERROR) + { + } + switch (e.reason) + { + case RETURN_ERROR: ... + } + + */ + +#define TRY_CATCH(EXCEPTION,MASK) \ + { \ + SIGJMP_BUF *buf = \ + exceptions_state_mc_init (&(EXCEPTION), (MASK)); \ + SIGSETJMP (*buf); \ + } \ + while (exceptions_state_mc_action_iter ()) \ + while (exceptions_state_mc_action_iter_1 ()) + +/* *INDENT-ON* */ + +/* Hook to allow client-specific actions to be performed prior to + throwing an exception. This function must be provided by the + client, and will be called before any cleanups are run. */ + +extern void prepare_to_throw_exception (void); + +/* Throw an exception (as described by "struct gdb_exception"). Will + execute a LONG JUMP to the inner most containing exception handler + established using catch_exceptions() (or similar). + + Code normally throws an exception using error() et.al. For various + reaons, GDB also contains code that throws an exception directly. + For instance, the remote*.c targets contain CNTRL-C signal handlers + that propogate the QUIT event up the exception chain. ``This could + be a good thing or a dangerous thing.'' -- the Existential + Wombat. */ + +extern void throw_exception (struct gdb_exception exception) + ATTRIBUTE_NORETURN; +extern void throw_verror (enum errors, const char *fmt, va_list ap) + ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 0); +extern void throw_vquit (const char *fmt, va_list ap) + ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (1, 0); +extern void throw_error (enum errors error, const char *fmt, ...) + ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 3); +extern void throw_quit (const char *fmt, ...) + ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (1, 2); + +#endif /* COMMON_EXCEPTIONS_H */ |