[PATCH] stdlib: DIAG_IGNORE_NEEDS_COMMENT setenv.c

[PATCH] stdlib: DIAG_IGNORE_NEEDS_COMMENT setenv.c

[Adhemerval Zanella]

Checked on x86_64-linux-gnu.
---
 stdlib/setenv.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/stdlib/setenv.c b/stdlib/setenv.c
index 2176cbac31..2add8bfb41 100644
--- a/stdlib/setenv.c
+++ b/stdlib/setenv.c
@@ -19,12 +19,14 @@
 # include <config.h>
 #endif
 
+#if _LIBC
+# include <libc-diag.h>
 /* Pacify GCC; see the commentary about VALLEN below.  This is needed
    at least through GCC 4.9.2.  Pacify GCC for the entire file, as
    there seems to be no way to pacify GCC selectively, only for the
-   place where it's needed.  Do not use DIAG_IGNORE_NEEDS_COMMENT
-   here, as it's not defined yet.  */
-#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+   place where it's needed.  */
+DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
+#endif
 
 #include <errno.h>
 #if !_LIBC
-- 
2.34.1

Re: [PATCH] stdlib: DIAG_IGNORE_NEEDS_COMMENT setenv.c

[Florian Weimer]

* Adhemerval Zanella via Libc-alpha:

> Checked on x86_64-linux-gnu.
> ---
>  stdlib/setenv.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/stdlib/setenv.c b/stdlib/setenv.c
> index 2176cbac31..2add8bfb41 100644
> --- a/stdlib/setenv.c
> +++ b/stdlib/setenv.c
> @@ -19,12 +19,14 @@
>  # include <config.h>
>  #endif
>  
> +#if _LIBC
> +# include <libc-diag.h>
>  /* Pacify GCC; see the commentary about VALLEN below.  This is needed
>     at least through GCC 4.9.2.  Pacify GCC for the entire file, as
>     there seems to be no way to pacify GCC selectively, only for the
> -   place where it's needed.  Do not use DIAG_IGNORE_NEEDS_COMMENT
> -   here, as it's not defined yet.  */
> -#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
> +   place where it's needed.  */
> +DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
> +#endif

The comment was added in:

commit 03c1e456b079929a8290aeb4aadb05c0df73bfd2
Author: Paul Eggert <eggert@cs.ucla.edu>
Date:   Sun Apr 19 01:06:33 2015 -0700

    Better fix for setenv (..., NULL, ...)
    
    * stdlib/setenv.c (__add_to_environ):
    Dump core quickly if setenv (..., NULL, ...) is called.
    This time, do it the right way, and pacify GCC with a pragma.

Paul, what did you mean when you wrote “not defined yet”?  Is it a
gnulib thing?

Thanks,
Florian

Re: [PATCH] stdlib: DIAG_IGNORE_NEEDS_COMMENT setenv.c

[Florian Weimer]

* Adhemerval Zanella via Libc-alpha:

> Checked on x86_64-linux-gnu.
> ---
>  stdlib/setenv.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/stdlib/setenv.c b/stdlib/setenv.c
> index 2176cbac31..2add8bfb41 100644
> --- a/stdlib/setenv.c
> +++ b/stdlib/setenv.c
> @@ -19,12 +19,14 @@
>  # include <config.h>
>  #endif
>  
> +#if _LIBC
> +# include <libc-diag.h>
>  /* Pacify GCC; see the commentary about VALLEN below.  This is needed
>     at least through GCC 4.9.2.  Pacify GCC for the entire file, as
>     there seems to be no way to pacify GCC selectively, only for the
> -   place where it's needed.  Do not use DIAG_IGNORE_NEEDS_COMMENT
> -   here, as it's not defined yet.  */
> -#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
> +   place where it's needed.  */
> +DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
> +#endif

The comment was added in:

commit 03c1e456b079929a8290aeb4aadb05c0df73bfd2
Author: Paul Eggert <eggert@cs.ucla.edu>
Date:   Sun Apr 19 01:06:33 2015 -0700

    Better fix for setenv (..., NULL, ...)
    
    * stdlib/setenv.c (__add_to_environ):
    Dump core quickly if setenv (..., NULL, ...) is called.
    This time, do it the right way, and pacify GCC with a pragma.

Paul, what did you mean when you wrote “not defined yet”?  Is it a
gnulib thing?

Thanks,
Florian

Re: [PATCH] stdlib: DIAG_IGNORE_NEEDS_COMMENT setenv.c

[Adhemerval Zanella Netto]

On 30/08/22 04:15, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
> 
>> Checked on x86_64-linux-gnu.
>> ---
>>  stdlib/setenv.c | 8 +++++---
>>  1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/stdlib/setenv.c b/stdlib/setenv.c
>> index 2176cbac31..2add8bfb41 100644
>> --- a/stdlib/setenv.c
>> +++ b/stdlib/setenv.c
>> @@ -19,12 +19,14 @@
>>  # include <config.h>
>>  #endif
>>  
>> +#if _LIBC
>> +# include <libc-diag.h>
>>  /* Pacify GCC; see the commentary about VALLEN below.  This is needed
>>     at least through GCC 4.9.2.  Pacify GCC for the entire file, as
>>     there seems to be no way to pacify GCC selectively, only for the
>> -   place where it's needed.  Do not use DIAG_IGNORE_NEEDS_COMMENT
>> -   here, as it's not defined yet.  */
>> -#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
>> +   place where it's needed.  */
>> +DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
>> +#endif
> 
> The comment was added in:
> 
> commit 03c1e456b079929a8290aeb4aadb05c0df73bfd2
> Author: Paul Eggert <eggert@cs.ucla.edu>
> Date:   Sun Apr 19 01:06:33 2015 -0700
> 
>     Better fix for setenv (..., NULL, ...)
>     
>     * stdlib/setenv.c (__add_to_environ):
>     Dump core quickly if setenv (..., NULL, ...) is called.
>     This time, do it the right way, and pacify GCC with a pragma.
> 
> Paul, what did you mean when you wrote “not defined yet”?  Is it a
> gnulib thing?

Paul, is anything to prevent us to use DIAG_IGNORE_NEEDS_COMMENT here?
For glibc it is the best way to possible handle different compiler that
might not need to define it.