commit f1b1d515aa5836844cdb45e8bb2b941784f78fd2
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Mon Apr 22 18:00:06 2024 +0200

    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.
    
    (cherry picked from commit cf5f7791056b3ed993bc8024be767a86157514a9)

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 74268b6a482..658063bd0a4 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 5d0c5fe8177..f1bcc1fbbc8 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 3cac2190ec7..48e7ef64afb 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 f607532aa90..03e4e23c686 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 5732633c7e4..7375dc88bb1 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 eb4d064177c..864bc20f146 100644
--- a/libstdc++-v3/testsuite/17_intro/names.cc
+++ b/libstdc++-v3/testsuite/17_intro/names.cc
@@ -267,6 +267,12 @@
 #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