Simplify exception handling
Now that cleanups have been removed, TRY/CATCH can't be SJLJ-based any more. This patch simplifies the exception handling code, by removing the non-working variants. Note that the "pure" C++ exception handling code is removed as well; I think the route forward must be to change exceptions to be self-destructing, so that try_scope_depth can simply be removed. Some longjmp-based code remains, as it is needed to throw an exception through readline. gdb/ChangeLog 2019-04-08 Tom Tromey <tom@tromey.com> * common/common-exceptions.h (GDB_XCPT_SJMP, GDB_XCPT_TRY) (GDB_XCPT_RAW_TRY, GDB_XCPT): Remove. (TRY, CATCH, END_CATCH): Remove some definitions. * common/common-exceptions.c: Don't use GDB_XCPT. (catcher_list_size): Remove. (throw_exception, throw_it): Simplify.
This commit is contained in:
Tom Tromey
parent
d970ee2bae
commit
c5c1011821
@ -1,3 +1,12 @@
|
||||
2019-04-08 Tom Tromey <tom@tromey.com>
|
||||
|
||||
* common/common-exceptions.h (GDB_XCPT_SJMP, GDB_XCPT_TRY)
|
||||
(GDB_XCPT_RAW_TRY, GDB_XCPT): Remove.
|
||||
(TRY, CATCH, END_CATCH): Remove some definitions.
|
||||
* common/common-exceptions.c: Don't use GDB_XCPT.
|
||||
(catcher_list_size): Remove.
|
||||
(throw_exception, throw_it): Simplify.
|
||||
|
||||
2019-04-05 Tom Tromey <tom@tromey.com>
|
||||
|
||||
Revert the header-sorting patch.
|
||||
|
||||
@ -54,26 +54,6 @@ struct catcher
|
||||
/* Where to go for throw_exception(). */
|
||||
static struct catcher *current_catcher;
|
||||
|
||||
#if GDB_XCPT == GDB_XCPT_SJMP
|
||||
|
||||
/* 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;
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
jmp_buf *
|
||||
exceptions_state_mc_init (void)
|
||||
{
|
||||
@ -205,8 +185,6 @@ exceptions_state_mc_action_iter_1 (void)
|
||||
return exceptions_state_mc (CATCH_ITER_1);
|
||||
}
|
||||
|
||||
#if GDB_XCPT != GDB_XCPT_SJMP
|
||||
|
||||
/* How many nested TRY blocks we have. See exception_messages and
|
||||
throw_it. */
|
||||
|
||||
@ -248,8 +226,6 @@ gdb_exception_sliced_copy (struct gdb_exception *to, const struct gdb_exception
|
||||
*to = *from;
|
||||
}
|
||||
|
||||
#endif /* !GDB_XCPT_SJMP */
|
||||
|
||||
/* Return EXCEPTION to the nearest containing CATCH_SJLJ block. */
|
||||
|
||||
void
|
||||
@ -263,8 +239,6 @@ throw_exception_sjlj (struct gdb_exception exception)
|
||||
longjmp (current_catcher->buf, exception.reason);
|
||||
}
|
||||
|
||||
#if GDB_XCPT != GDB_XCPT_SJMP
|
||||
|
||||
/* Implementation of throw_exception that uses C++ try/catch. */
|
||||
|
||||
static ATTRIBUTE_NORETURN void
|
||||
@ -288,16 +262,10 @@ throw_exception_cxx (struct gdb_exception exception)
|
||||
gdb_assert_not_reached ("invalid return reason");
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
void
|
||||
throw_exception (struct gdb_exception exception)
|
||||
{
|
||||
#if GDB_XCPT == GDB_XCPT_SJMP
|
||||
throw_exception_sjlj (exception);
|
||||
#else
|
||||
throw_exception_cxx (exception);
|
||||
#endif
|
||||
}
|
||||
|
||||
/* A stack of exception messages.
|
||||
@ -321,11 +289,7 @@ throw_it (enum return_reason reason, enum errors error, const char *fmt,
|
||||
{
|
||||
struct gdb_exception e;
|
||||
char *new_message;
|
||||
#if GDB_XCPT == GDB_XCPT_SJMP
|
||||
int depth = catcher_list_size ();
|
||||
#else
|
||||
int depth = try_scope_depth;
|
||||
#endif
|
||||
|
||||
gdb_assert (depth > 0);
|
||||
|
||||
|
||||
@ -115,22 +115,6 @@ struct gdb_exception
|
||||
const char *message;
|
||||
};
|
||||
|
||||
/* The different exception mechanisms that TRY/CATCH can map to. */
|
||||
|
||||
/* Make GDB exceptions use setjmp/longjmp behind the scenes. */
|
||||
#define GDB_XCPT_SJMP 1
|
||||
|
||||
/* Make GDB exceptions use try/catch behind the scenes. */
|
||||
#define GDB_XCPT_TRY 2
|
||||
|
||||
/* Specify this mode to build with TRY/CATCH mapped directly to raw
|
||||
try/catch. GDB won't work correctly, but building that way catches
|
||||
code tryin to break/continue out of the try block, along with
|
||||
spurious code between the TRY and the CATCH block. */
|
||||
#define GDB_XCPT_RAW_TRY 3
|
||||
|
||||
#define GDB_XCPT GDB_XCPT_TRY
|
||||
|
||||
/* Functions to drive the sjlj-based exceptions state machine. Though
|
||||
declared here by necessity, these functions should be considered
|
||||
internal to the exceptions subsystem and not used other than via
|
||||
@ -141,13 +125,11 @@ extern int exceptions_state_mc_action_iter (void);
|
||||
extern int exceptions_state_mc_action_iter_1 (void);
|
||||
extern int exceptions_state_mc_catch (struct gdb_exception *, int);
|
||||
|
||||
/* Same, but for the C++ try/catch-based TRY/CATCH mechanism. */
|
||||
/* For the C++ try/catch-based TRY/CATCH mechanism. */
|
||||
|
||||
#if GDB_XCPT != GDB_XCPT_SJMP
|
||||
extern void *exception_try_scope_entry (void);
|
||||
extern void exception_try_scope_exit (void *saved_state);
|
||||
extern void exception_rethrow (void) ATTRIBUTE_NORETURN;
|
||||
#endif
|
||||
|
||||
/* Macro to wrap up standard try/catch behavior.
|
||||
|
||||
@ -196,19 +178,6 @@ extern void exception_rethrow (void) ATTRIBUTE_NORETURN;
|
||||
#define END_CATCH_SJLJ \
|
||||
}
|
||||
|
||||
#if GDB_XCPT == GDB_XCPT_SJMP
|
||||
|
||||
/* If using SJLJ-based exceptions for all exceptions, then provide
|
||||
standard aliases. */
|
||||
|
||||
#define TRY TRY_SJLJ
|
||||
#define CATCH CATCH_SJLJ
|
||||
#define END_CATCH END_CATCH_SJLJ
|
||||
|
||||
#endif /* GDB_XCPT_SJMP */
|
||||
|
||||
#if GDB_XCPT == GDB_XCPT_TRY || GDB_XCPT == GDB_XCPT_RAW_TRY
|
||||
|
||||
/* Prevent error/quit during TRY from calling cleanups established
|
||||
prior to here. This pops out the scope in either case of normal
|
||||
exit or exception exit. */
|
||||
@ -226,8 +195,6 @@ struct exception_try_scope
|
||||
void *saved_state;
|
||||
};
|
||||
|
||||
#if GDB_XCPT == GDB_XCPT_TRY
|
||||
|
||||
/* We still need to wrap TRY/CATCH in C++ so that cleanups and C++
|
||||
exceptions can coexist.
|
||||
|
||||
@ -263,15 +230,6 @@ struct exception_try_scope
|
||||
} \
|
||||
}
|
||||
|
||||
#else
|
||||
|
||||
#define TRY try
|
||||
#define CATCH(EXCEPTION, MASK) \
|
||||
catch (struct gdb_exception ## _ ## MASK &EXCEPTION)
|
||||
#define END_CATCH
|
||||
|
||||
#endif
|
||||
|
||||
/* The exception types client code may catch. They're just shims
|
||||
around gdb_exception that add nothing but type info. Which is used
|
||||
is selected depending on the MASK argument passed to CATCH. */
|
||||
@ -288,8 +246,6 @@ struct gdb_exception_RETURN_MASK_QUIT : public gdb_exception_RETURN_MASK_ALL
|
||||
{
|
||||
};
|
||||
|
||||
#endif /* GDB_XCPT_TRY || GDB_XCPT_RAW_TRY */
|
||||
|
||||
/* An exception type that inherits from both std::bad_alloc and a gdb
|
||||
exception. This is necessary because operator new can only throw
|
||||
std::bad_alloc, and OTOH, we want exceptions thrown due to memory
|
||||
|
||||
Loading…
Reference in New Issue
Block a user