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