[v2,19/22] Make exception throwing a bit more efficient
Commit Message
This makes exception throwing a bit more efficient, by removing some
copies. This is good now that exceptions are more expensive to copy.
gdb/ChangeLog
2019-02-27 Tom Tromey <tom@tromey.com>
* common/common-exceptions.c (throw_exception): Rename from
throw_exception_cxx. Remove old copy. Make argument const.
(throw_it): Create and throw exception objects directly.
* common/common-exceptions.h (throw_exception): Make argument
const.
---
gdb/ChangeLog | 8 ++++++++
gdb/common/common-exceptions.c | 37 ++++++++++++++++++++--------------
gdb/common/common-exceptions.h | 2 +-
3 files changed, 31 insertions(+), 16 deletions(-)
Comments
On 02/27/2019 08:18 PM, Tom Tromey wrote:
> This makes exception throwing a bit more efficient, by removing some
> copies. This is good now that exceptions are more expensive to copy.
It will no longer be expensive if we follow the idea of
refcounting the message, but seems fine anyway.
> -static ATTRIBUTE_NORETURN void
> -throw_exception_cxx (struct gdb_exception exception)
> +void
> +throw_exception (const struct gdb_exception &exception)
throw_exception (const gdb_exception &exception)
?
> --- a/gdb/common/common-exceptions.h
> +++ b/gdb/common/common-exceptions.h
> @@ -205,7 +205,7 @@ struct gdb_quit_bad_alloc
> /* Throw an exception (as described by "struct gdb_exception"),
> landing in the inner most containing exception handler established
> using TRY/CATCH. */
> -extern void throw_exception (struct gdb_exception exception)
> +extern void throw_exception (const struct gdb_exception &exception)
> ATTRIBUTE_NORETURN;
Ditto.
Thanks,
Pedro Alves
@@ -188,8 +188,8 @@ throw_exception_sjlj (struct gdb_exception exception)
/* Implementation of throw_exception that uses C++ try/catch. */
-static ATTRIBUTE_NORETURN void
-throw_exception_cxx (struct gdb_exception exception)
+void
+throw_exception (const struct gdb_exception &exception)
{
if (exception.reason == RETURN_QUIT)
{
@@ -209,25 +209,32 @@ throw_exception_cxx (struct gdb_exception exception)
gdb_assert_not_reached ("invalid return reason");
}
-void
-throw_exception (struct gdb_exception exception)
-{
- throw_exception_cxx (exception);
-}
-
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;
+ if (reason == RETURN_QUIT)
+ {
+ gdb_exception_quit ex;
- /* Create the exception. */
- e.reason = reason;
- e.error = error;
- e.message = string_vprintf (fmt, ap);
+ ex.reason = reason;
+ ex.error = error;
+ ex.message = string_vprintf (fmt, ap);
- /* Throw the exception. */
- throw_exception (e);
+ throw ex;
+ }
+ else if (reason == RETURN_ERROR)
+ {
+ gdb_exception_error ex;
+
+ ex.reason = reason;
+ ex.error = error;
+ ex.message = string_vprintf (fmt, ap);
+
+ throw ex;
+ }
+ else
+ gdb_assert_not_reached ("invalid return reason");
}
void
@@ -205,7 +205,7 @@ struct gdb_quit_bad_alloc
/* Throw an exception (as described by "struct gdb_exception"),
landing in the inner most containing exception handler established
using TRY/CATCH. */
-extern void throw_exception (struct gdb_exception exception)
+extern void throw_exception (const struct gdb_exception &exception)
ATTRIBUTE_NORETURN;
/* Throw an exception by executing a LONG JUMP to the inner most