[PATCH] add attribute none to pthread_setspecific (BZ #27714)

[Joseph Myers]

On Tue, 27 Apr 2021, Martin Sebor via Libc-alpha wrote:

> These are warnings in my build (I've seen a few others scroll by
> and have always assumed they were expected(*)).  Those you pasted

Most warnings are errors by default (unless you use --disable-werror, 
which should never normally be used in glibc development unless you're 
e.g. reviewing the warnings you get if you add extra warning options to 
those with which glibc is built by default, in order to fix those warnings 
before adding the extra options).

> I test by simply running make check.  I can make the change to
> the test if you expect warning-free test builds.

We expect builds, for all glibc ABIs, free from compile errors or failures 
of tests that can run without needing to execute any code for the glibc 
architecture.  That means no warnings that are turned into errors by 
-Werror.  There are some warnings for which -Wno-error or pragmas are used 
to stop them being errors; all other warnings are disallowed.

> [*] Here's an example of a warning I just noticed while rerunning
> make check:
> 
> tst-chk1.c: In function ‘do_test’:

That's an example covered by -Wno-error.

# We know these tests have problems with format strings, this is what
# we are testing.  Disable that warning.  They are also testing
# deprecated functions (notably gets) so disable that warning as well.
# And they also generate warnings from warning attributes, which
# cannot be disabled via pragmas, so require -Wno-error to be used.
CFLAGS-tst-chk1.c += -Wno-format -Wno-deprecated-declarations -Wno-error

(Any code disabling any warnings or disabling -Werror for them is expected 
to have a comment explaining why it's OK to do so in that case.)

-- 
Joseph S. Myers
joseph@codesourcery.com