libstdc++: Workaround kernel-headers on s390x-linux

We see
FAIL: 17_intro/headers/c++1998/all_attributes.cc   (test for excess errors)
FAIL: 17_intro/headers/c++2011/all_attributes.cc   (test for excess errors)
FAIL: 17_intro/headers/c++2014/all_attributes.cc   (test for excess errors)
FAIL: 17_intro/headers/c++2017/all_attributes.cc   (test for excess errors)
FAIL: 17_intro/headers/c++2020/all_attributes.cc   (test for excess errors)
FAIL: 17_intro/names.cc  -std=gnu++17 (test for excess errors)
on s390x-linux.
The first 5 are due to kernel-headers not using uglified attribute names,
where <asm/types.h> contains
__attribute__((packed, aligned(4)))
I've filed a downstream bugreport for this in
https://bugzilla.redhat.com/show_bug.cgi?id=2276084
(not really sure where to report kernel-headers issues upstream), while the
last one is due to <sys/ucontext.h> from glibc containing:
  #ifdef __USE_MISC
  # define __ctx(fld) fld
  #else
  # define __ctx(fld) __ ## fld
  #endif
  ...
  typedef union
    {
      double  __ctx(d);
      float   __ctx(f);
    } fpreg_t;
and g++ predefining -D_GNU_SOURCE which implies define __USE_MISC.

The following patch adds a workaround for this on the libstdc++ testsuite
side.

2024-04-22  Jakub Jelinek  <jakub@redhat.com>

	* testsuite/17_intro/names.cc (d, f): Undefine on s390*-linux*.
	* testsuite/17_intro/headers/c++1998/all_attributes.cc (packed): Don't
	define on s390.
	* testsuite/17_intro/headers/c++2011/all_attributes.cc (packed):
	Likewise.
	* testsuite/17_intro/headers/c++2014/all_attributes.cc (packed):
	Likewise.
	* testsuite/17_intro/headers/c++2017/all_attributes.cc (packed):
	Likewise.
	* testsuite/17_intro/headers/c++2020/all_attributes.cc (packed):
	Likewise.

6 files changed, 26 insertions, 0 deletions

diff --git a/libstdc++-v3/testsuite/17_intro/headers/c++1998/all_attributes.cc b/libstdc++-v3/testsuite/17_intro/headers/c++1998/all_attributes.cc
index ae81846..0c38259 100644
--- a/libstdc++-v3/testsuite/17_intro/headers/c++1998/all_attributes.cc
+++ b/libstdc++-v3/testsuite/17_intro/headers/c++1998/all_attributes.cc
@@ -29,7 +29,11 @@
 # define noreturn 1
 # define visibility 1
 #endif
+#ifndef __s390__
+// kernel-headers <asm/types.h> uses __attribute__((packed,aligned(4))) on
+// S390.
 #define packed 1
+#endif
 #define pure 1
 // glibc's sysdeps/unix/sysv/linux/arm/sys/ucontext.h uses this on ARM.
 #ifndef __arm__
diff --git a/libstdc++-v3/testsuite/17_intro/headers/c++2011/all_attributes.cc b/libstdc++-v3/testsuite/17_intro/headers/c++2011/all_attributes.cc
index 5f7f31a..cc34a35 100644
--- a/libstdc++-v3/testsuite/17_intro/headers/c++2011/all_attributes.cc
+++ b/libstdc++-v3/testsuite/17_intro/headers/c++2011/all_attributes.cc
@@ -29,7 +29,11 @@
 # define visibility 1
 #endif
 #define no_unique_address 1
+#ifndef __s390__
+// kernel-headers <asm/types.h> uses __attribute__((packed,aligned(4))) on
+// S390.
 #define packed 1
+#endif
 #define pure 1
 // glibc's sysdeps/unix/sysv/linux/arm/sys/ucontext.h uses this on ARM.
 #ifndef __arm__
diff --git a/libstdc++-v3/testsuite/17_intro/headers/c++2014/all_attributes.cc b/libstdc++-v3/testsuite/17_intro/headers/c++2014/all_attributes.cc
index befc1ca..80d0852 100644
--- a/libstdc++-v3/testsuite/17_intro/headers/c++2014/all_attributes.cc
+++ b/libstdc++-v3/testsuite/17_intro/headers/c++2014/all_attributes.cc
@@ -29,7 +29,11 @@
 # define visibility 1
 #endif
 #define no_unique_address 1
+#ifndef __s390__
+// kernel-headers <asm/types.h> uses __attribute__((packed,aligned(4))) on
+// S390.
 #define packed 1
+#endif
 #define pure 1
 // glibc's sysdeps/unix/sysv/linux/arm/sys/ucontext.h uses this on ARM.
 #ifndef __arm__
diff --git a/libstdc++-v3/testsuite/17_intro/headers/c++2017/all_attributes.cc b/libstdc++-v3/testsuite/17_intro/headers/c++2017/all_attributes.cc
index a59fe1b..4f8ba4d 100644
--- a/libstdc++-v3/testsuite/17_intro/headers/c++2017/all_attributes.cc
+++ b/libstdc++-v3/testsuite/17_intro/headers/c++2017/all_attributes.cc
@@ -28,7 +28,11 @@
 # define visibility 1
 #endif
 #define no_unique_address 1
+#ifndef __s390__
+// kernel-headers <asm/types.h> uses __attribute__((packed,aligned(4))) on
+// S390.
 #define packed 1
+#endif
 #define pure 1
 // glibc's sysdeps/unix/sysv/linux/arm/sys/ucontext.h uses this on ARM.
 #ifndef __arm__
diff --git a/libstdc++-v3/testsuite/17_intro/headers/c++2020/all_attributes.cc b/libstdc++-v3/testsuite/17_intro/headers/c++2020/all_attributes.cc
index 0c54ab6..3de1488 100644
--- a/libstdc++-v3/testsuite/17_intro/headers/c++2020/all_attributes.cc
+++ b/libstdc++-v3/testsuite/17_intro/headers/c++2020/all_attributes.cc
@@ -27,7 +27,11 @@
 # define cold 1
 # define visibility 1
 #endif
+#ifndef __s390__
+// kernel-headers <asm/types.h> uses __attribute__((packed,aligned(4))) on
+// S390.
 #define packed 1
+#endif
 #define pure 1
 // glibc's sysdeps/unix/sysv/linux/arm/sys/ucontext.h uses this on ARM.
 #ifndef __arm__
diff --git a/libstdc++-v3/testsuite/17_intro/names.cc b/libstdc++-v3/testsuite/17_intro/names.cc
index 784da9a..9b0ffcb 100644
--- a/libstdc++-v3/testsuite/17_intro/names.cc
+++ b/libstdc++-v3/testsuite/17_intro/names.cc
@@ -270,6 +270,12 @@
 #undef u
 #endif
 
+#if defined (__linux__) && defined (__s390__)
+// <sys/ucontext.h> defines fpreg_t::d and fpreg_t::f
+#undef d
+#undef f
+#endif
+
 #if defined (__linux__) && defined (__sparc__)
 #undef y
 #endif