[PATCH] gdb, btrace: fix error diagnostics

[PATCH] gdb, btrace: fix error diagnostics

[Markus Metzger]

When we improved error messages in

    cd393cec3ab gdb, btrace: improve error messages

we cleared the original errno.  When the error reason can not be explained
in a more detailed error message, and we fall back to the default error
message, it now gives Success as error.

Restore the original errno to fix that.
---
 gdb/nat/linux-btrace.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/gdb/nat/linux-btrace.c b/gdb/nat/linux-btrace.c
index 50de2415589..f8352b62b8b 100644
--- a/gdb/nat/linux-btrace.c
+++ b/gdb/nat/linux-btrace.c
@@ -422,7 +422,8 @@ cpu_supports_bts (void)
 static void
 diagnose_perf_event_open_fail ()
 {
-  switch (errno)
+  int orig_errno = errno;
+  switch (orig_errno)
     {
     case EPERM:
     case EACCES:
@@ -443,7 +444,7 @@ diagnose_perf_event_open_fail ()
       break;
     }
 
-  error (_("Failed to start recording: %s"), safe_strerror (errno));
+  error (_("Failed to start recording: %s"), safe_strerror (orig_errno));
 }
 
 /* Get the linux version of a btrace_target_info.  */
-- 
2.34.1

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Re: [PATCH] gdb, btrace: fix error diagnostics

[Guinevere Larsen]

On 07/03/2024 16:01, Markus Metzger wrote:
> When we improved error messages in
>
>      cd393cec3ab gdb, btrace: improve error messages
>
> we cleared the original errno.  When the error reason can not be explained
> in a more detailed error message, and we fall back to the default error
> message, it now gives Success as error.
>
> Restore the original errno to fix that.

Hi!

LGTM, Reviewed-By: Guinevere Larsen <blarsen@redhat.com>

-- 
Cheers,
Guinevere Larsen
She/Her/Hers

> ---
>   gdb/nat/linux-btrace.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/gdb/nat/linux-btrace.c b/gdb/nat/linux-btrace.c
> index 50de2415589..f8352b62b8b 100644
> --- a/gdb/nat/linux-btrace.c
> +++ b/gdb/nat/linux-btrace.c
> @@ -422,7 +422,8 @@ cpu_supports_bts (void)
>   static void
>   diagnose_perf_event_open_fail ()
>   {
> -  switch (errno)
> +  int orig_errno = errno;
> +  switch (orig_errno)
>       {
>       case EPERM:
>       case EACCES:
> @@ -443,7 +444,7 @@ diagnose_perf_event_open_fail ()
>         break;
>       }
>   
> -  error (_("Failed to start recording: %s"), safe_strerror (errno));
> +  error (_("Failed to start recording: %s"), safe_strerror (orig_errno));
>   }
>   
>   /* Get the linux version of a btrace_target_info.  */

Re: [PATCH] gdb, btrace: fix error diagnostics

[Tom Tromey]

>>>>> Markus Metzger <markus.t.metzger@intel.com> writes:

> When we improved error messages in
>     cd393cec3ab gdb, btrace: improve error messages

> we cleared the original errno.  When the error reason can not be explained
> in a more detailed error message, and we fall back to the default error
> message, it now gives Success as error.

> Restore the original errno to fix that.

Thank you.  This looks good to me.
Approved-By: Tom Tromey <tom@tromey.com>

Tom