properly disable -fsplit-stack on non-glibc targets [PR104170]

On Sat, Jan 22, 2022 at 10:32:21AM +0100, Martin Liška wrote:
> I've just noticed the patch broke a few cross compilers:
>
> s390x-ibm-tpf:
>
> /home/marxin/buildworker/zen2-cross-compilers/build/gcc/common/config/s390/s390-common.cc: In function ‘bool s390_supports_split_stack(bool, gcc_options*)’:
> /home/marxin/buildworker/zen2-cross-compilers/build/gcc/common/config/s390/s390-common.cc:126:13: error: ‘struct gcc_options’ has no member named ‘x_linux_libc’
>   126 |   if (opts->x_linux_libc == LIBC_GLIBC)
>       |             ^~~~~~~~~~~~
>
> i686-kopensolaris-gnu, i686-symbolics-gnu
>
> /home/marxin/buildworker/zen2-cross-compilers/build/gcc/common/config/i386/i386-common.cc: In function ‘bool ix86_supports_split_stack(bool, gcc_options*)’:
> /home/marxin/buildworker/zen2-cross-compilers/build/gcc/common/config/i386/i386-common.cc:1721:13: error: ‘struct gcc_options’ has no member named ‘x_linux_libc’
>  1721 |   if (opts->x_linux_libc != LIBC_GLIBC)
>       |             ^~~~~~~~~~~~
> make[1]: *** [Makefile:2418: i386-common.o] Error 1
>
> Can you please take a look? Btw. do you have a bugzilla account?

I bet instead of opts->x_linux_libc != LIBC_GLIBC it needs to use
 #ifdef OPTION_GLIBC
   if (!OPTION_GLIBC)
 #endif
or so.  I think the first committed patch actually used that
but used it in #if directive, which is wrong because it is something
that needs to be evaluated at runtime.

That doesn't work well either, because the *supports_split_stack
hooks have opts argument and OPTION_GLIBC doesn't take that.

So, here is a patch that introduces OPTION_*_P macros that take opts
as an argument and redefines OPTION_* using those (similarly to how
the option scripts create TARGET_*_P and TARGET_* macros).

2022-01-24  Jakub Jelinek  <jakub@redhat.com>

	PR bootstrap/104170
	* config/linux.h (OPTION_GLIBC_P, OPTION_UCLIBC_P,
	OPTION_BIONIC_P, OPTION_MUSL_P): Define.
	(OPTION_GLIBC, OPTION_UCLIBC, OPTION_BIONIC, OPTION_MUSL): Redefine
	using OPTION_*_P macros.
	* config/alpha/linux.h (OPTION_GLIBC_P, OPTION_UCLIBC_P,
	OPTION_BIONIC_P, OPTION_MUSL_P): Define.
	(OPTION_GLIBC, OPTION_UCLIBC, OPTION_BIONIC, OPTION_MUSL): Redefine
	using OPTION_*_P macros.
	* config/rs6000/linux.h (OPTION_GLIBC_P, OPTION_UCLIBC_P,
	OPTION_BIONIC_P, OPTION_MUSL_P): Define.
	(OPTION_GLIBC, OPTION_UCLIBC, OPTION_BIONIC, OPTION_MUSL): Redefine
	using OPTION_*_P macros.
	* config/rs6000/linux64.h (OPTION_GLIBC_P, OPTION_UCLIBC_P,
	OPTION_BIONIC_P, OPTION_MUSL_P): Define.
	(OPTION_GLIBC, OPTION_UCLIBC, OPTION_BIONIC, OPTION_MUSL): Redefine
	using OPTION_*_P macros.
	* config/fuchsia.h (OPTION_MUSL_P): Redefine.
	* config/glibc-stdint.h (OPTION_MUSL_P): Define if not defined.
	* common/config/s390/s390-common.cc (s390_supports_split_stack): Re-add
	ATTRIBUTE_UNUSED to opts parameter.  If OPTION_GLIBC_P is defined, use
	OPTION_GLIBC_P (opts) as condition, otherwise assume if (false).
	* common/config/i386/i386-common.cc (ix86_supports_split_stack): If
	OPTION_GLIBC_P is defined use !OPTION_GLIBC_P (opts) as condition,
	otherwise assume if (true).

2 files changed, 6 insertions, 4 deletions

diff --git a/gcc/common/config/i386/i386-common.cc b/gcc/common/config/i386/i386-common.cc
index 7496d17..607e9f2 100644
--- a/gcc/common/config/i386/i386-common.cc
+++ b/gcc/common/config/i386/i386-common.cc
@@ -1717,8 +1717,8 @@ static bool
 ix86_supports_split_stack (bool report,
 			   struct gcc_options *opts ATTRIBUTE_UNUSED)
 {
-#ifdef TARGET_THREAD_SPLIT_STACK_OFFSET
-  if (opts->x_linux_libc != LIBC_GLIBC)
+#if defined(TARGET_THREAD_SPLIT_STACK_OFFSET) && defined(OPTION_GLIBC_P)
+  if (!OPTION_GLIBC_P (opts))
 #endif
     {
       if (report)
diff --git a/gcc/common/config/s390/s390-common.cc b/gcc/common/config/s390/s390-common.cc
index 547b082..caec2f1 100644
--- a/gcc/common/config/s390/s390-common.cc
+++ b/gcc/common/config/s390/s390-common.cc
@@ -121,10 +121,12 @@ s390_handle_option (struct gcc_options *opts ATTRIBUTE_UNUSED,
 
 static bool
 s390_supports_split_stack (bool report,
-			   struct gcc_options *opts)
+			   struct gcc_options *opts ATTRIBUTE_UNUSED)
 {
-  if (opts->x_linux_libc == LIBC_GLIBC)
+#ifdef OPTION_GLIBC_P
+  if (OPTION_GLIBC_P (opts))
     return true;
+#endif
 
   if (report)
     error ("%<-fsplit-stack%> currently only supported on GNU/Linux");