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Introduce common/common-exceptions.[ch]

Browse Source 
This commit moves the exception throwing and catching code
into gdb/common/.  All exception printing code remains in
gdb/exceptions.[ch].

gdb/ChangeLog:

	* common/common-exceptions.h: New file.
	* common/common-exceptions.c: Likewise.
	* Makefile.in (SFILES): Add common/common-exceptions.c.
	(HFILES_NO_SRCDIR): Add common/common-exceptions.h.
	(COMMON_OBS): Add common-exceptions.o.
	(common-exceptions.o): New rule.
	* exceptions.h (common-exceptions.h): Include.
	(gdb_setjmp.h): Do not include.
	(return_reason): Moved to common-exceptions.h.
	(enum return_reason): Likewise.
	(RETURN_MASK): Likewise.
	(typedef return_mask): Likewise.
	(enum errors): Likewise.
	(struct gdb_exception): Likewise.
	(exceptions_state_mc_init): Likewise.
	(exceptions_state_mc_action_iter): Likewise.
	(exceptions_state_mc_action_iter_1): Likewise.
	(TRY_CATCH): Likewise.
	(throw_exception): Likewise.
	(throw_verror): Likewise.
	(throw_vquit): Likewise.
	(throw_error): Likewise.
	(throw_quit): Likewise.
	* exceptions.c (enum catcher_state): Moved to common-exceptions.c.
	(enum catcher_action): Likewise.
	(struct catcher): Likewise.
	(current_catcher): Likewise.
	(catcher_list_size): Likewise.
	(exceptions_state_mc_init): Likewise.
	(catcher_pop): Likewise.
	(exceptions_state_mc): Likewise.
	(exceptions_state_mc_action_iter): Likewise.
	(exceptions_state_mc_action_iter_1): Likewise.
	(throw_exception): Likewise.
	(exception_messages): Likewise.
	(exception_messages_size): Likewise.
	(throw_it): Likewise.
	(throw_verror): Likewise.
	(throw_vquit): Likewise.
	(throw_error): Likewise.
	(throw_quit): Likewise.
	(prepare_to_throw_exception): New function.

gdb/gdbserver/ChangeLog:

	* Makefile.in (SFILES): Add common/common-exceptions.c.
	(OBS): Add common-exceptions.o.
	(common-exceptions.o): New rule.
	* utils.c (prepare_to_throw_exception): New function.
This commit is contained in:
Gary Benson 2014-08-07 16:29:19 +01:00
parent e9bcb65852
commit ff55e1b548
9 changed files with 570 additions and 438 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
gdb/ChangeLog
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@ -1,3 +1,48 @@
2014-08-29 Gary Benson <gbenson@redhat.com>
* common/common-exceptions.h: New file.
* common/common-exceptions.c: Likewise.
* Makefile.in (SFILES): Add common/common-exceptions.c.
(HFILES_NO_SRCDIR): Add common/common-exceptions.h.
(COMMON_OBS): Add common-exceptions.o.
(common-exceptions.o): New rule.
* exceptions.h (common-exceptions.h): Include.
(gdb_setjmp.h): Do not include.
(return_reason): Moved to common-exceptions.h.
(enum return_reason): Likewise.
(RETURN_MASK): Likewise.
(typedef return_mask): Likewise.
(enum errors): Likewise.
(struct gdb_exception): Likewise.
(exceptions_state_mc_init): Likewise.
(exceptions_state_mc_action_iter): Likewise.
(exceptions_state_mc_action_iter_1): Likewise.
(TRY_CATCH): Likewise.
(throw_exception): Likewise.
(throw_verror): Likewise.
(throw_vquit): Likewise.
(throw_error): Likewise.
(throw_quit): Likewise.
* exceptions.c (enum catcher_state): Moved to common-exceptions.c.
(enum catcher_action): Likewise.
(struct catcher): Likewise.
(current_catcher): Likewise.
(catcher_list_size): Likewise.
(exceptions_state_mc_init): Likewise.
(catcher_pop): Likewise.
(exceptions_state_mc): Likewise.
(exceptions_state_mc_action_iter): Likewise.
(exceptions_state_mc_action_iter_1): Likewise.
(throw_exception): Likewise.
(exception_messages): Likewise.
(exception_messages_size): Likewise.
(throw_it): Likewise.
(throw_verror): Likewise.
(throw_vquit): Likewise.
(throw_error): Likewise.
(throw_quit): Likewise.
(prepare_to_throw_exception): New function.
2014-08-29 Gary Benson <gbenson@redhat.com>
* common/gdb_setjmp.h: New file.

12
gdb/Makefile.in
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@ -851,7 +851,7 @@ SFILES = ada-exp.y ada-lang.c ada-typeprint.c ada-valprint.c ada-tasks.c \
common/ptid.c common/buffer.c gdb-dlfcn.c common/agent.c \
common/format.c common/filestuff.c btrace.c record-btrace.c ctf.c \
target/waitstatus.c common/print-utils.c common/rsp-low.c \
common/errors.c common/common-debug.c
common/errors.c common/common-debug.c common/common-exceptions.c
LINTFILES = $(SFILES) $(YYFILES) $(CONFIG_SRCS) init.c
@ -937,7 +937,8 @@ ctf.h nat/i386-cpuid.h nat/i386-gcc-cpuid.h target/resume.h \
target/wait.h target/waitstatus.h nat/linux-nat.h nat/linux-waitpid.h \
common/print-utils.h common/rsp-low.h nat/i386-dregs.h x86-linux-nat.h \
i386-linux-nat.h common/common-defs.h common/errors.h common/common-types.h \
common/common-debug.h common/cleanups.h common/gdb_setjmp.h
common/common-debug.h common/cleanups.h common/gdb_setjmp.h \
common/common-exceptions.h
# Header files that already have srcdir in them, or which are in objdir.
@ -1036,7 +1037,8 @@ COMMON_OBS = $(DEPFILES) $(CONFIG_OBS) $(YYOBJ) \
gdb_vecs.o jit.o progspace.o skip.o probe.o \
common-utils.o buffer.o ptid.o gdb-dlfcn.o common-agent.o \
format.o registry.o btrace.o record-btrace.o waitstatus.o \
print-utils.o rsp-low.o errors.o common-debug.o debug.o
print-utils.o rsp-low.o errors.o common-debug.o debug.o \
common-exceptions.o
TSOBS = inflow.o
@ -2166,6 +2168,10 @@ cleanups.o: ${srcdir}/common/cleanups.c
$(COMPILE) $(srcdir)/common/cleanups.c
$(POSTCOMPILE)
common-exceptions.o: ${srcdir}/common/common-exceptions.c
$(COMPILE) $(srcdir)/common/common-exceptions.c
$(POSTCOMPILE)
#
# gdb/target/ dependencies
#

308
gdb/common/common-exceptions.c Normal file
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@ -0,0 +1,308 @@
/* 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/>. */
#include "common-defs.h"
#include "common-exceptions.h"
#include "cleanups.h"
/* Possible catcher states. */
enum catcher_state {
/* Initial state, a new catcher has just been created. */
CATCHER_CREATED,
/* The catch code is running. */
CATCHER_RUNNING,
CATCHER_RUNNING_1,
/* The catch code threw an exception. */
CATCHER_ABORTING
};
/* Possible catcher actions. */
enum catcher_action {
CATCH_ITER,
CATCH_ITER_1,
CATCH_THROWING
};
struct catcher
{
enum catcher_state state;
/* Jump buffer pointing back at the exception handler. */
SIGJMP_BUF buf;
/* Status buffer belonging to the exception handler. */
volatile struct gdb_exception *exception;
/* Saved/current state. */
int mask;
struct cleanup *saved_cleanup_chain;
/* Back link. */
struct catcher *prev;
};
/* Where to go for throw_exception(). */
static struct catcher *current_catcher;
/* Return length of current_catcher list. */
static int
catcher_list_size (void)
{
int size;
struct catcher *catcher;
for (size = 0, catcher = current_catcher;
catcher != NULL;
catcher = catcher->prev)
++size;
return size;
}
SIGJMP_BUF *
exceptions_state_mc_init (volatile struct gdb_exception *exception,
return_mask mask)
{
struct catcher *new_catcher = XCNEW (struct catcher);
/* Start with no exception, save it's address. */
exception->reason = 0;
exception->error = GDB_NO_ERROR;
exception->message = NULL;
new_catcher->exception = exception;
new_catcher->mask = mask;
/* Prevent error/quit during FUNC from calling cleanups established
prior to here. */
new_catcher->saved_cleanup_chain = save_cleanups ();
/* Push this new catcher on the top. */
new_catcher->prev = current_catcher;
current_catcher = new_catcher;
new_catcher->state = CATCHER_CREATED;
return &new_catcher->buf;
}
static void
catcher_pop (void)
{
struct catcher *old_catcher = current_catcher;
current_catcher = old_catcher->prev;
/* Restore the cleanup chain, the error/quit messages, and the uiout
builder, to their original states. */
restore_cleanups (old_catcher->saved_cleanup_chain);
xfree (old_catcher);
}
/* Catcher state machine. Returns non-zero if the m/c should be run
again, zero if it should abort. */
static int
exceptions_state_mc (enum catcher_action action)
{
switch (current_catcher->state)
{
case CATCHER_CREATED:
switch (action)
{
case CATCH_ITER:
/* Allow the code to run the catcher. */
current_catcher->state = CATCHER_RUNNING;
return 1;
default:
internal_error (__FILE__, __LINE__, _("bad state"));
}
case CATCHER_RUNNING:
switch (action)
{
case CATCH_ITER:
/* No error/quit has occured. Just clean up. */
catcher_pop ();
return 0;
case CATCH_ITER_1:
current_catcher->state = CATCHER_RUNNING_1;
return 1;
case CATCH_THROWING:
current_catcher->state = CATCHER_ABORTING;
/* See also throw_exception. */
return 1;
default:
internal_error (__FILE__, __LINE__, _("bad switch"));
}
case CATCHER_RUNNING_1:
switch (action)
{
case CATCH_ITER:
/* The did a "break" from the inner while loop. */
catcher_pop ();
return 0;
case CATCH_ITER_1:
current_catcher->state = CATCHER_RUNNING;
return 0;
case CATCH_THROWING:
current_catcher->state = CATCHER_ABORTING;
/* See also throw_exception. */
return 1;
default:
internal_error (__FILE__, __LINE__, _("bad switch"));
}
case CATCHER_ABORTING:
switch (action)
{
case CATCH_ITER:
{
struct gdb_exception exception = *current_catcher->exception;
if (current_catcher->mask & RETURN_MASK (exception.reason))
{
/* Exit normally if this catcher can handle this
exception. The caller analyses the func return
values. */
catcher_pop ();
return 0;
}
/* The caller didn't request that the event be caught,
relay the event to the next containing
catch_errors(). */
catcher_pop ();
throw_exception (exception);
}
default:
internal_error (__FILE__, __LINE__, _("bad state"));
}
default:
internal_error (__FILE__, __LINE__, _("bad switch"));
}
}
int
exceptions_state_mc_action_iter (void)
{
return exceptions_state_mc (CATCH_ITER);
}
int
exceptions_state_mc_action_iter_1 (void)
{
return exceptions_state_mc (CATCH_ITER_1);
}
/* Return EXCEPTION to the nearest containing catch_errors(). */
void
throw_exception (struct gdb_exception exception)
{
prepare_to_throw_exception ();
do_cleanups (all_cleanups ());
/* Jump to the containing catch_errors() call, communicating REASON
to that call via setjmp's return value. Note that REASON can't
be zero, by definition in defs.h. */
exceptions_state_mc (CATCH_THROWING);
*current_catcher->exception = exception;
SIGLONGJMP (current_catcher->buf, exception.reason);
}
/* A stack of exception messages.
This is needed to handle nested calls to throw_it: we don't want to
xfree space for a message before it's used.
This can happen if we throw an exception during a cleanup:
An outer TRY_CATCH may have an exception message it wants to print,
but while doing cleanups further calls to throw_it are made.
This is indexed by the size of the current_catcher list.
It is a dynamically allocated array so that we don't care how deeply
GDB nests its TRY_CATCHs. */
static char **exception_messages;
/* The number of currently allocated entries in exception_messages. */
static int exception_messages_size;
static void ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (3, 0)
throw_it (enum return_reason reason, enum errors error, const char *fmt,
va_list ap)
{
struct gdb_exception e;
char *new_message;
int depth = catcher_list_size ();
gdb_assert (depth > 0);
/* Note: The new message may use an old message's text. */
new_message = xstrvprintf (fmt, ap);
if (depth > exception_messages_size)
{
int old_size = exception_messages_size;
exception_messages_size = depth + 10;
exception_messages = (char **) xrealloc (exception_messages,
exception_messages_size
* sizeof (char *));
memset (exception_messages + old_size, 0,
(exception_messages_size - old_size) * sizeof (char *));
}
xfree (exception_messages[depth - 1]);
exception_messages[depth - 1] = new_message;
/* Create the exception. */
e.reason = reason;
e.error = error;
e.message = new_message;
/* Throw the exception. */
throw_exception (e);
}
void
throw_verror (enum errors error, const char *fmt, va_list ap)
{
throw_it (RETURN_ERROR, error, fmt, ap);
}
void
throw_vquit (const char *fmt, va_list ap)
{
throw_it (RETURN_QUIT, GDB_NO_ERROR, fmt, ap);
}
void
throw_error (enum errors error, const char *fmt, ...)
{
va_list args;
va_start (args, fmt);
throw_verror (error, fmt, args);
va_end (args);
}
void
throw_quit (const char *fmt, ...)
{
va_list args;
va_start (args, fmt);
throw_vquit (fmt, args);
va_end (args);
}

185
gdb/common/common-exceptions.h Normal file
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@ -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 */

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@ -29,207 +29,11 @@
const struct gdb_exception exception_none = { 0, GDB_NO_ERROR, NULL };
/* Possible catcher states. */
enum catcher_state {
/* Initial state, a new catcher has just been created. */
CATCHER_CREATED,
/* The catch code is running. */
CATCHER_RUNNING,
CATCHER_RUNNING_1,
/* The catch code threw an exception. */
CATCHER_ABORTING
};
/* Possible catcher actions. */
enum catcher_action {
CATCH_ITER,
CATCH_ITER_1,
CATCH_THROWING
};
struct catcher
{
enum catcher_state state;
/* Jump buffer pointing back at the exception handler. */
SIGJMP_BUF buf;
/* Status buffer belonging to the exception handler. */
volatile struct gdb_exception *exception;
/* Saved/current state. */
int mask;
struct cleanup *saved_cleanup_chain;
/* Back link. */
struct catcher *prev;
};
/* Where to go for throw_exception(). */
static struct catcher *current_catcher;
/* Return length of current_catcher list. */
static int
catcher_list_size (void)
{
int size;
struct catcher *catcher;
for (size = 0, catcher = current_catcher;
catcher != NULL;
catcher = catcher->prev)
++size;
return size;
}
SIGJMP_BUF *
exceptions_state_mc_init (volatile struct gdb_exception *exception,
return_mask mask)
{
struct catcher *new_catcher = XCNEW (struct catcher);
/* Start with no exception, save it's address. */
exception->reason = 0;
exception->error = GDB_NO_ERROR;
exception->message = NULL;
new_catcher->exception = exception;
new_catcher->mask = mask;
/* Prevent error/quit during FUNC from calling cleanups established
prior to here. */
new_catcher->saved_cleanup_chain = save_cleanups ();
/* Push this new catcher on the top. */
new_catcher->prev = current_catcher;
current_catcher = new_catcher;
new_catcher->state = CATCHER_CREATED;
return &new_catcher->buf;
}
static void
catcher_pop (void)
{
struct catcher *old_catcher = current_catcher;
current_catcher = old_catcher->prev;
/* Restore the cleanup chain, the error/quit messages, and the uiout
builder, to their original states. */
restore_cleanups (old_catcher->saved_cleanup_chain);
xfree (old_catcher);
}
/* Catcher state machine. Returns non-zero if the m/c should be run
again, zero if it should abort. */
static int
exceptions_state_mc (enum catcher_action action)
{
switch (current_catcher->state)
{
case CATCHER_CREATED:
switch (action)
{
case CATCH_ITER:
/* Allow the code to run the catcher. */
current_catcher->state = CATCHER_RUNNING;
return 1;
default:
internal_error (__FILE__, __LINE__, _("bad state"));
}
case CATCHER_RUNNING:
switch (action)
{
case CATCH_ITER:
/* No error/quit has occured. Just clean up. */
catcher_pop ();
return 0;
case CATCH_ITER_1:
current_catcher->state = CATCHER_RUNNING_1;
return 1;
case CATCH_THROWING:
current_catcher->state = CATCHER_ABORTING;
/* See also throw_exception. */
return 1;
default:
internal_error (__FILE__, __LINE__, _("bad switch"));
}
case CATCHER_RUNNING_1:
switch (action)
{
case CATCH_ITER:
/* The did a "break" from the inner while loop. */
catcher_pop ();
return 0;
case CATCH_ITER_1:
current_catcher->state = CATCHER_RUNNING;
return 0;
case CATCH_THROWING:
current_catcher->state = CATCHER_ABORTING;
/* See also throw_exception. */
return 1;
default:
internal_error (__FILE__, __LINE__, _("bad switch"));
}
case CATCHER_ABORTING:
switch (action)
{
case CATCH_ITER:
{
struct gdb_exception exception = *current_catcher->exception;
if (current_catcher->mask & RETURN_MASK (exception.reason))
{
/* Exit normally if this catcher can handle this
exception. The caller analyses the func return
values. */
catcher_pop ();
return 0;
}
/* The caller didn't request that the event be caught,
relay the event to the next containing
catch_errors(). */
catcher_pop ();
throw_exception (exception);
}
default:
internal_error (__FILE__, __LINE__, _("bad state"));
}
default:
internal_error (__FILE__, __LINE__, _("bad switch"));
}
}
int
exceptions_state_mc_action_iter (void)
{
return exceptions_state_mc (CATCH_ITER);
}
int
exceptions_state_mc_action_iter_1 (void)
{
return exceptions_state_mc (CATCH_ITER_1);
}
/* Return EXCEPTION to the nearest containing catch_errors(). */
void
throw_exception (struct gdb_exception exception)
prepare_to_throw_exception (void)
{
clear_quit_flag ();
immediate_quit = 0;
do_cleanups (all_cleanups ());
/* Jump to the containing catch_errors() call, communicating REASON
to that call via setjmp's return value. Note that REASON can't
be zero, by definition in defs.h. */
exceptions_state_mc (CATCH_THROWING);
*current_catcher->exception = exception;
SIGLONGJMP (current_catcher->buf, exception.reason);
}
static void
@ -332,90 +136,6 @@ exception_fprintf (struct ui_file *file, struct gdb_exception e,
}
}
/* A stack of exception messages.
This is needed to handle nested calls to throw_it: we don't want to
xfree space for a message before it's used.
This can happen if we throw an exception during a cleanup:
An outer TRY_CATCH may have an exception message it wants to print,
but while doing cleanups further calls to throw_it are made.
This is indexed by the size of the current_catcher list.
It is a dynamically allocated array so that we don't care how deeply
GDB nests its TRY_CATCHs. */
static char **exception_messages;
/* The number of currently allocated entries in exception_messages. */
static int exception_messages_size;
static void ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (3, 0)
throw_it (enum return_reason reason, enum errors error, const char *fmt,
va_list ap)
{
struct gdb_exception e;
char *new_message;
int depth = catcher_list_size ();
gdb_assert (depth > 0);
/* Note: The new message may use an old message's text. */
new_message = xstrvprintf (fmt, ap);
if (depth > exception_messages_size)
{
int old_size = exception_messages_size;
exception_messages_size = depth + 10;
exception_messages = (char **) xrealloc (exception_messages,
exception_messages_size
* sizeof (char *));
memset (exception_messages + old_size, 0,
(exception_messages_size - old_size) * sizeof (char *));
}
xfree (exception_messages[depth - 1]);
exception_messages[depth - 1] = new_message;
/* Create the exception. */
e.reason = reason;
e.error = error;
e.message = new_message;
/* Throw the exception. */
throw_exception (e);
}
void
throw_verror (enum errors error, const char *fmt, va_list ap)
{
throw_it (RETURN_ERROR, error, fmt, ap);
}
void
throw_vquit (const char *fmt, va_list ap)
{
throw_it (RETURN_QUIT, GDB_NO_ERROR, fmt, ap);
}
void
throw_error (enum errors error, const char *fmt, ...)
{
va_list args;
va_start (args, fmt);
throw_verror (error, fmt, args);
va_end (args);
}
void
throw_quit (const char *fmt, ...)
{
va_list args;
va_start (args, fmt);
throw_vquit (fmt, args);
va_end (args);
}
/* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
handler. If an exception (enum return_reason) is thrown using
throw_exception() than all cleanups installed since

154
gdb/exceptions.h
View File

@ -20,142 +20,12 @@
#ifndef EXCEPTIONS_H
#define EXCEPTIONS_H
#include "common-exceptions.h"
#include "ui-out.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;
};
/* A pre-defined non-exception. */
extern const struct gdb_exception exception_none;
/* Functions to drive the exceptions state m/c (internal to
exceptions). */
SIGJMP_BUF *exceptions_state_mc_init (volatile struct
gdb_exception *exception,
return_mask mask);
int exceptions_state_mc_action_iter (void);
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* */
/* If E is an exception, print it's error message on the specified
stream. For _fprintf, prefix the message with PREFIX... */
extern void exception_print (struct ui_file *file, struct gdb_exception e);
@ -163,28 +33,6 @@ extern void exception_fprintf (struct ui_file *file, struct gdb_exception e,
const char *prefix,
...) ATTRIBUTE_PRINTF (3, 4);
/* 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);
/* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
handler. If an exception (enum return_reason) is thrown using
throw_exception() than all cleanups installed since

7
gdb/gdbserver/ChangeLog
View File

@ -1,3 +1,10 @@
2014-08-29 Gary Benson <gbenson@redhat.com>
* Makefile.in (SFILES): Add common/common-exceptions.c.
(OBS): Add common-exceptions.o.
(common-exceptions.o): New rule.
* utils.c (prepare_to_throw_exception): New function.
2014-08-29 Gary Benson <gbenson@redhat.com>
* config.in: Regenerate.

7
gdb/gdbserver/Makefile.in
View File

@ -170,7 +170,8 @@ SFILES= $(srcdir)/gdbreplay.c $(srcdir)/inferiors.c $(srcdir)/dll.c \
$(srcdir)/common/filestuff.c $(srcdir)/target/waitstatus.c \
$(srcdir)/nat/mips-linux-watch.c $(srcdir)/common/print-utils.c \
$(srcdir)/common/rsp-low.c $(srcdir)/common/errors.c \
$(srcdir)/common/common-debug.c $(srcdir)/common/cleanups.c
$(srcdir)/common/common-debug.c $(srcdir)/common/cleanups.c \
$(srcdir)/common/common-exceptions.c
DEPFILES = @GDBSERVER_DEPFILES@
@ -184,6 +185,7 @@ OBS = agent.o ax.o inferiors.o regcache.o remote-utils.o server.o signals.o \
mem-break.o hostio.o event-loop.o tracepoint.o xml-utils.o \
common-utils.o ptid.o buffer.o format.o filestuff.o dll.o notif.o \
tdesc.o print-utils.o rsp-low.o errors.o common-debug.o cleanups.o \
common-exceptions.o \
$(XML_BUILTIN) $(DEPFILES) $(LIBOBJS)
GDBREPLAY_OBS = gdbreplay.o version.o
GDBSERVER_LIBS = @GDBSERVER_LIBS@
@ -547,6 +549,9 @@ common-debug.o: ../common/common-debug.c
cleanups.o: ../common/cleanups.c
$(COMPILE) $<
$(POSTCOMPILE)
common-exceptions.o: ../common/common-exceptions.c
$(COMPILE) $<
$(POSTCOMPILE)
waitstatus.o: ../target/waitstatus.c
$(COMPILE) $<
$(POSTCOMPILE)

8
gdb/gdbserver/utils.c
View File

@ -141,3 +141,11 @@ pfildes (gdb_fildes_t fd)
return plongest (fd);
#endif
}
/* See common/common-exceptions.h. */
void
prepare_to_throw_exception (void)
{
/* No client-specific actions required. */
}