[RFA,2/4] Change gdbscm_exception_message_to_string to return a unique_xmalloc_ptr
Commit Message
This changes gdbscm_exception_message_to_string to return a
unique_xmalloc_ptr, allowing for the removal of some cleanups.
unique_xmalloc_ptr was chosen because at the root of the call chains
is a function from Guile that returns a malloc'd string.
ChangeLog
2018-05-26 Tom Tromey <tom@tromey.com>
* guile/scm-param.c (pascm_signal_setshow_error): Update.
* guile/guile-internal.h (gdbscm_exception_message_to_string):
Update.
* guile/scm-cmd.c (cmdscm_function): Update.
* guile/scm-pretty-print.c
(ppscm_print_exception_unless_memory_error): Update.
* guile/scm-exception.c (gdbscm_exception_message_to_string):
Return unique_xmalloc_ptr.
---
gdb/ChangeLog | 11 +++++++++++
gdb/guile/guile-internal.h | 3 ++-
gdb/guile/scm-cmd.c | 6 +++---
gdb/guile/scm-exception.c | 11 ++++-------
gdb/guile/scm-param.c | 6 +++---
gdb/guile/scm-pretty-print.c | 17 ++++++++---------
6 files changed, 31 insertions(+), 23 deletions(-)
Comments
On 05/27/2018 04:20 PM, Tom Tromey wrote:
> ChangeLog
> 2018-05-26 Tom Tromey <tom@tromey.com>
>
> * guile/scm-param.c (pascm_signal_setshow_error): Update.
> * guile/guile-internal.h (gdbscm_exception_message_to_string):
> Update.
> * guile/scm-cmd.c (cmdscm_function): Update.
> * guile/scm-pretty-print.c
> (ppscm_print_exception_unless_memory_error): Update.
> * guile/scm-exception.c (gdbscm_exception_message_to_string):
> Return unique_xmalloc_ptr.
OK.
> @@ -601,9 +598,9 @@ gdbscm_exception_message_to_string (SCM exception)
> }
>
> gdbscm_print_exception_message (port, SCM_BOOL_F, key, args);
> - result = gdbscm_scm_to_c_string (scm_get_output_string (port));
> + gdb::unique_xmalloc_ptr<char> result
> + (gdbscm_scm_to_c_string (scm_get_output_string (port)));
> scm_close_port (port);
> -
> return result;
> }
Did you try making gdbscm_scm_to_c_string return a unique_ptr too?
Thanks,
Pedro Alves
>>>>> "Pedro" == Pedro Alves <palves@redhat.com> writes:
>> gdbscm_print_exception_message (port, SCM_BOOL_F, key, args);
>> - result = gdbscm_scm_to_c_string (scm_get_output_string (port));
>> + gdb::unique_xmalloc_ptr<char> result
>> + (gdbscm_scm_to_c_string (scm_get_output_string (port)));
>> scm_close_port (port);
>> -
>> return result;
>> }
Pedro> Did you try making gdbscm_scm_to_c_string return a unique_ptr too?
Yes, but this runs into the use of
GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS in (at least) gdbscm_value_field.
I haven't looked into what to do about this.
Tom
@@ -362,7 +362,8 @@ extern void gdbscm_print_exception_with_stack (SCM port, SCM stack,
extern void gdbscm_print_gdb_exception (SCM port, SCM exception);
-extern char *gdbscm_exception_message_to_string (SCM exception);
+extern gdb::unique_xmalloc_ptr<char> gdbscm_exception_message_to_string
+ (SCM exception);
extern excp_matcher_func gdbscm_memory_error_p;
@@ -316,10 +316,10 @@ cmdscm_function (struct cmd_list_element *command,
itself. */
if (gdbscm_user_error_p (gdbscm_exception_key (result)))
{
- char *msg = gdbscm_exception_message_to_string (result);
+ gdb::unique_xmalloc_ptr<char> msg
+ = gdbscm_exception_message_to_string (result);
- make_cleanup (xfree, msg);
- error ("%s", msg);
+ error ("%s", msg.get ());
}
else
{
@@ -575,16 +575,13 @@ gdbscm_print_gdb_exception (SCM port, SCM exception)
/* Return a string description of <gdb:exception> EXCEPTION.
If EXCEPTION is a gdb:with-stack exception, unwrap it, a backtrace
- is never returned as part of the result.
+ is never returned as part of the result. */
- Space for the result is malloc'd, the caller must free. */
-
-char *
+gdb::unique_xmalloc_ptr<char>
gdbscm_exception_message_to_string (SCM exception)
{
SCM port = scm_open_output_string ();
SCM key, args;
- char *result;
gdb_assert (gdbscm_is_exception (exception));
@@ -601,9 +598,9 @@ gdbscm_exception_message_to_string (SCM exception)
}
gdbscm_print_exception_message (port, SCM_BOOL_F, key, args);
- result = gdbscm_scm_to_c_string (scm_get_output_string (port));
+ gdb::unique_xmalloc_ptr<char> result
+ (gdbscm_scm_to_c_string (scm_get_output_string (port)));
scm_close_port (port);
-
return result;
}
@@ -251,10 +251,10 @@ pascm_signal_setshow_error (SCM exception, const char *msg)
itself. */
if (gdbscm_user_error_p (gdbscm_exception_key (exception)))
{
- char *excp_text = gdbscm_exception_message_to_string (exception);
+ gdb::unique_xmalloc_ptr<char> excp_text
+ = gdbscm_exception_message_to_string (exception);
- make_cleanup (xfree, excp_text);
- error ("%s", excp_text);
+ error ("%s", excp_text.get ());
}
else
{
@@ -614,25 +614,24 @@ ppscm_print_exception_unless_memory_error (SCM exception,
{
if (gdbscm_memory_error_p (gdbscm_exception_key (exception)))
{
- char *msg = gdbscm_exception_message_to_string (exception);
- struct cleanup *cleanup = make_cleanup (xfree, msg);
+ gdb::unique_xmalloc_ptr<char> msg
+ = gdbscm_exception_message_to_string (exception);
/* This "shouldn't happen", but play it safe. */
- if (msg == NULL || *msg == '\0')
+ if (msg == NULL || msg.get ()[0] == '\0')
fprintf_filtered (stream, _("<error reading variable>"));
else
{
/* Remove the trailing newline. We could instead call a special
routine for printing memory error messages, but this is easy
enough for now. */
- size_t len = strlen (msg);
+ char *msg_text = msg.get ();
+ size_t len = strlen (msg_text);
- if (msg[len - 1] == '\n')
- msg[len - 1] = '\0';
- fprintf_filtered (stream, _("<error reading variable: %s>"), msg);
+ if (msg_text[len - 1] == '\n')
+ msg_text[len - 1] = '\0';
+ fprintf_filtered (stream, _("<error reading variable: %s>"), msg_text);
}
-
- do_cleanups (cleanup);
}
else
gdbscm_print_gdb_exception (SCM_BOOL_F, exception);