[PATCH 1/1] gdb: Deprecate stabs debug info

[PATCH 1/1] gdb: Deprecate stabs debug info

[Guinevere Larsen]

GCC has deprecated stabs generation in GCC 12 and entirely removed it in
GCC 13, which was released in April 2023. At the time it was proposed
that GDB deprecate stabs as well, but the decision was to support it a
bit longer. With this patch, it'll be deprecated on GDB 17, and removed
on GDB 18, which following the current cadence, will be released early
2026, meaning we will have supported stabs for nearly 3 years longer
than GCC, which I think is reasonable.

As pointed out in the previous discussion on this topic[1], there are
several existing issues on the code, and none of the current maintainers
knows how to fix it.  Unless someone steps up to fix this before the
removal on GDB 18, I don't see why we should keep this old code that
breaks all conventions of modern debuginfo readers and doesn't even
work, instead of being able to further advance adjacent code.

[1] https://inbox.sourceware.org/gdb-patches/20230119174156.654402-1-tom@tromey.com/
---
 gdb/NEWS | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gdb/NEWS b/gdb/NEWS
index f454846646e..685ecefbe1c 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -44,6 +44,9 @@ maintenance check symtabs
   ** New constant PARAM_COLOR represents color type of a value
      of a <gdb:parameter> object.  Parameter's value is <gdb::color> instance.
 
+* Support for stabs debugging format is deprecates, and will be
+  removed in GDB 18.
+
 *** Changes in GDB 16
 
 * Support for Nios II targets has been removed as this architecture
-- 
2.47.1

Re: [PATCH 1/1] gdb: Deprecate stabs debug info

[Eli Zaretskii]

> From: Guinevere Larsen <guinevere@redhat.com>
> Cc: Guinevere Larsen <guinevere@redhat.com>
> Date: Mon, 13 Jan 2025 15:13:59 -0300
> 
> diff --git a/gdb/NEWS b/gdb/NEWS
> index f454846646e..685ecefbe1c 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -44,6 +44,9 @@ maintenance check symtabs
>    ** New constant PARAM_COLOR represents color type of a value
>       of a <gdb:parameter> object.  Parameter's value is <gdb::color> instance.
>  
> +* Support for stabs debugging format is deprecates, and will be
> +  removed in GDB 18.                    ^^^^^^^^^^

Typo.

Thanks.

Re: [PATCH 1/1] gdb: Deprecate stabs debug info

[Guinevere Larsen]

On 1/13/25 3:30 PM, Eli Zaretskii wrote:
>> From: Guinevere Larsen <guinevere@redhat.com>
>> Cc: Guinevere Larsen <guinevere@redhat.com>
>> Date: Mon, 13 Jan 2025 15:13:59 -0300
>>
>> diff --git a/gdb/NEWS b/gdb/NEWS
>> index f454846646e..685ecefbe1c 100644
>> --- a/gdb/NEWS
>> +++ b/gdb/NEWS
>> @@ -44,6 +44,9 @@ maintenance check symtabs
>>     ** New constant PARAM_COLOR represents color type of a value
>>        of a <gdb:parameter> object.  Parameter's value is <gdb::color> instance.
>>   
>> +* Support for stabs debugging format is deprecates, and will be
>> +  removed in GDB 18.                    ^^^^^^^^^^
> Typo.
>
> Thanks.
>
oops. Fixed!

-- 
Cheers,
Guinevere Larsen
She/Her/Hers

Re: [PATCH 1/1] gdb: Deprecate stabs debug info

[Tom Tromey]

>>>>> "Guinevere" == Guinevere Larsen <guinevere@redhat.com> writes:

Guinevere> As pointed out in the previous discussion on this topic[1], there are
Guinevere> several existing issues on the code, and none of the current maintainers
Guinevere> knows how to fix it.  Unless someone steps up to fix this before the
Guinevere> removal on GDB 18, I don't see why we should keep this old code that
Guinevere> breaks all conventions of modern debuginfo readers and doesn't even
Guinevere> work, instead of being able to further advance adjacent code.

I completely agree.
I'm in favor of this patch but I think you should wait a little while in
case there are any objections.

Approved-By: Tom Tromey <tom@tromey.com>

Also please add this trailer:

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31210

thanks,
Tom

Re: [PATCH 1/1] gdb: Deprecate stabs debug info

[Andrew Burgess]

Guinevere Larsen <guinevere@redhat.com> writes:

> GCC has deprecated stabs generation in GCC 12 and entirely removed it in
> GCC 13, which was released in April 2023. At the time it was proposed
> that GDB deprecate stabs as well, but the decision was to support it a
> bit longer. With this patch, it'll be deprecated on GDB 17, and removed
> on GDB 18, which following the current cadence, will be released early
> 2026, meaning we will have supported stabs for nearly 3 years longer
> than GCC, which I think is reasonable.
>
> As pointed out in the previous discussion on this topic[1], there are
> several existing issues on the code, and none of the current maintainers
> knows how to fix it.  Unless someone steps up to fix this before the
> removal on GDB 18, I don't see why we should keep this old code that
> breaks all conventions of modern debuginfo readers and doesn't even
> work, instead of being able to further advance adjacent code.

I'm in favour of this.  Like Tom said, lets give folk a chance to object
before merging this, but hopefully this should allow removal of some old
code.

Approved-By: Andrew Burgess <aburgess@redhat.com>

Thanks,
Andrew


>
> [1] https://inbox.sourceware.org/gdb-patches/20230119174156.654402-1-tom@tromey.com/
> ---
>  gdb/NEWS | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/gdb/NEWS b/gdb/NEWS
> index f454846646e..685ecefbe1c 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -44,6 +44,9 @@ maintenance check symtabs
>    ** New constant PARAM_COLOR represents color type of a value
>       of a <gdb:parameter> object.  Parameter's value is <gdb::color> instance.
>  
> +* Support for stabs debugging format is deprecates, and will be
> +  removed in GDB 18.
> +
>  *** Changes in GDB 16
>  
>  * Support for Nios II targets has been removed as this architecture
> -- 
> 2.47.1

Re: [PATCH 1/1] gdb: Deprecate stabs debug info

[Tom de Vries]

On 1/13/25 19:13, Guinevere Larsen wrote:
> GCC has deprecated stabs generation in GCC 12 and entirely removed it in
> GCC 13, which was released in April 2023. At the time it was proposed
> that GDB deprecate stabs as well, but the decision was to support it a
> bit longer. With this patch, it'll be deprecated on GDB 17, and removed
> on GDB 18, which following the current cadence, will be released early
> 2026, meaning we will have supported stabs for nearly 3 years longer
> than GCC, which I think is reasonable.
> 
> As pointed out in the previous discussion on this topic[1], there are
> several existing issues on the code, and none of the current maintainers
> knows how to fix it.  Unless someone steps up to fix this before the
> removal on GDB 18, I don't see why we should keep this old code that
> breaks all conventions of modern debuginfo readers and doesn't even
> work, instead of being able to further advance adjacent code.
> 

Hi Gwen,

please add the bug tag for PR31210 - "[gdb, symtab] Deprecate stabs":

   Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31210

Thanks,
- Tom


> [1] https://inbox.sourceware.org/gdb-patches/20230119174156.654402-1-tom@tromey.com/
> ---
>   gdb/NEWS | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/gdb/NEWS b/gdb/NEWS
> index f454846646e..685ecefbe1c 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -44,6 +44,9 @@ maintenance check symtabs
>     ** New constant PARAM_COLOR represents color type of a value
>        of a <gdb:parameter> object.  Parameter's value is <gdb::color> instance.
>   
> +* Support for stabs debugging format is deprecates, and will be
> +  removed in GDB 18.
> +
>   *** Changes in GDB 16
>   
>   * Support for Nios II targets has been removed as this architecture

Re: [PATCH 1/1] gdb: Deprecate stabs debug info

[Guinevere Larsen]

Ping.

I'm planning on pushing this next monday, so if anyone has negative 
feedback on this, speak now or forever hold your peace.

-- 
Cheers,
Guinevere Larsen
She/Her/Hers

On 1/13/25 3:13 PM, Guinevere Larsen wrote:
> GCC has deprecated stabs generation in GCC 12 and entirely removed it in
> GCC 13, which was released in April 2023. At the time it was proposed
> that GDB deprecate stabs as well, but the decision was to support it a
> bit longer. With this patch, it'll be deprecated on GDB 17, and removed
> on GDB 18, which following the current cadence, will be released early
> 2026, meaning we will have supported stabs for nearly 3 years longer
> than GCC, which I think is reasonable.
>
> As pointed out in the previous discussion on this topic[1], there are
> several existing issues on the code, and none of the current maintainers
> knows how to fix it.  Unless someone steps up to fix this before the
> removal on GDB 18, I don't see why we should keep this old code that
> breaks all conventions of modern debuginfo readers and doesn't even
> work, instead of being able to further advance adjacent code.
>
> [1] https://inbox.sourceware.org/gdb-patches/20230119174156.654402-1-tom@tromey.com/
> ---
>   gdb/NEWS | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/gdb/NEWS b/gdb/NEWS
> index f454846646e..685ecefbe1c 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -44,6 +44,9 @@ maintenance check symtabs
>     ** New constant PARAM_COLOR represents color type of a value
>        of a <gdb:parameter> object.  Parameter's value is <gdb::color> instance.
>   
> +* Support for stabs debugging format is deprecates, and will be
> +  removed in GDB 18.
> +
>   *** Changes in GDB 16
>   
>   * Support for Nios II targets has been removed as this architecture

[PATCH v2] gdb: Deprecate stabs debug info

[Guinevere Larsen]

GCC has deprecated stabs generation in GCC 12 and entirely removed it in
GCC 13, which was released in April 2023. At the time it was proposed
that GDB deprecate stabs as well, but the decision was to support it a
bit longer. With this patch, it'll be deprecated on GDB 17, and removed
on GDB 18, which following the current cadence, will be released early
2026, meaning we will have supported stabs for nearly 3 years longer
than GCC, which I think is reasonable.

As pointed out in the previous discussion on this topic[1], there are
several existing issues on the code, and none of the current maintainers
knows how to fix it.  Unless someone steps up to fix this before the
removal on GDB 18, I don't see why we should keep this old code that
breaks all conventions of modern debuginfo readers and doesn't even
work, instead of being able to further advance adjacent code.

Finally, deprecating and removing stabs will make a.out/dbx inferiors be
essentially unsupported, as the only debuginfo GDB supports for those
formats is stabs, meaning users would only have assembly-level debugging
for that format. With that in mind, this commit deprecates the a.out/dbx
format as well.

[1] https://inbox.sourceware.org/gdb-patches/20230119174156.654402-1-tom@tromey.com/

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31210
---
 gdb/NEWS | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gdb/NEWS b/gdb/NEWS
index eec7cf4695d..92006c85e97 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -46,6 +46,9 @@ maintenance check symtabs
   ** New constant PARAM_COLOR represents color type of a value
      of a <gdb:parameter> object.  Parameter's value is <gdb::color> instance.
 
+* Support for stabs debugging format and the a.out/dbx object format is
+  deprecated, and will be removed in GDB 18.
+
 *** Changes in GDB 16
 
 * Support for Nios II targets has been removed as this architecture
-- 
2.48.1

Re: [PATCH v2] gdb: Deprecate stabs debug info

[Eli Zaretskii]

> From: Guinevere Larsen <guinevere@redhat.com>
> Cc: Guinevere Larsen <guinevere@redhat.com>
> Date: Mon, 27 Jan 2025 15:47:50 -0300
> 
> GCC has deprecated stabs generation in GCC 12 and entirely removed it in
> GCC 13, which was released in April 2023. At the time it was proposed
> that GDB deprecate stabs as well, but the decision was to support it a
> bit longer. With this patch, it'll be deprecated on GDB 17, and removed
> on GDB 18, which following the current cadence, will be released early
> 2026, meaning we will have supported stabs for nearly 3 years longer
> than GCC, which I think is reasonable.
> 
> As pointed out in the previous discussion on this topic[1], there are
> several existing issues on the code, and none of the current maintainers
> knows how to fix it.  Unless someone steps up to fix this before the
> removal on GDB 18, I don't see why we should keep this old code that
> breaks all conventions of modern debuginfo readers and doesn't even
> work, instead of being able to further advance adjacent code.
> 
> Finally, deprecating and removing stabs will make a.out/dbx inferiors be
> essentially unsupported, as the only debuginfo GDB supports for those
> formats is stabs, meaning users would only have assembly-level debugging
> for that format. With that in mind, this commit deprecates the a.out/dbx
> format as well.
> 
> [1] https://inbox.sourceware.org/gdb-patches/20230119174156.654402-1-tom@tromey.com/
> 
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31210
> ---
>  gdb/NEWS | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/gdb/NEWS b/gdb/NEWS
> index eec7cf4695d..92006c85e97 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -46,6 +46,9 @@ maintenance check symtabs
>    ** New constant PARAM_COLOR represents color type of a value
>       of a <gdb:parameter> object.  Parameter's value is <gdb::color> instance.
>  
> +* Support for stabs debugging format and the a.out/dbx object format is
> +  deprecated, and will be removed in GDB 18.
> +
>  *** Changes in GDB 16
>  
>  * Support for Nios II targets has been removed as this architecture
> -- 

This is okay, provided that everyone agrees with this schedule (I'm
just okaying the change to NEWS here).

Re: [PATCH v2] gdb: Deprecate stabs debug info

[Tom Tromey]

>>>>> "Guinevere" == Guinevere Larsen <guinevere@redhat.com> writes:

Guinevere> +* Support for stabs debugging format and the a.out/dbx object format is
Guinevere> +  deprecated, and will be removed in GDB 18.

Thank you.
Approved-By: Tom Tromey <tom@tromey.com>

Tom

Re: [PATCH v2] gdb: Deprecate stabs debug info

[Guinevere Larsen]

On 1/28/25 2:47 PM, Tom Tromey wrote:
>>>>>> "Guinevere" == Guinevere Larsen <guinevere@redhat.com> writes:
> Guinevere> +* Support for stabs debugging format and the a.out/dbx object format is
> Guinevere> +  deprecated, and will be removed in GDB 18.
>
> Thank you.
> Approved-By: Tom Tromey <tom@tromey.com>
>
> Tom
>
Thanks for the approval!

I'll wait 2 weeks before pushing, so that people have a chance to react 
to the extra deprecation of a.out/dbx, and push it if no one has feedback

-- 
Cheers,
Guinevere Larsen
She/Her/Hers

Re: [PATCH v2] gdb: Deprecate stabs debug info

[Guinevere Larsen]

On 1/28/25 2:47 PM, Tom Tromey wrote:
>>>>>> "Guinevere" == Guinevere Larsen <guinevere@redhat.com> writes:
> Guinevere> +* Support for stabs debugging format and the a.out/dbx object format is
> Guinevere> +  deprecated, and will be removed in GDB 18.
>
> Thank you.
> Approved-By: Tom Tromey <tom@tromey.com>
>
> Tom
>
It's been 2 weeks since the patch was sent, and no negative comments 
happened, so I went ahead and pushed the patch.

-- 
Cheers,
Guinevere Larsen
She/Her/Hers