@@ -32,4 +32,33 @@ if test "$libc_cv_target_power8_ok" != "yes"; then :
fi
CFLAGS="$OLD_CFLAGS"
+# Local configure fragment for sysdeps/powerpc/powerpc64le.
+
+OLD_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -mno-gnu-attribute"
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if the compiler supports -mno-gnu-attribute" >&5
+$as_echo_n "checking if the compiler supports -mno-gnu-attribute... " >&6; }
+if ${libc_cv_no_gnu_attr_ok+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+ libc_cv_no_gnu_attr_ok=yes
+else
+ libc_cv_no_gnu_attr_ok=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_no_gnu_attr_ok" >&5
+$as_echo "$libc_cv_no_gnu_attr_ok" >&6; }
+if test "$libc_cv_no_gnu_attr_ok" != "yes"; then :
+ critic_missing="$critic_missing A compiler with -mno-gnu-attribute is required on powerpc64le."
+fi
+CFLAGS="$OLD_CFLAGS"
+
test -n "$critic_missing" && as_fn_error $? "*** $critic_missing" "$LINENO" 5
@@ -17,4 +17,19 @@ AS_IF([test "$libc_cv_target_power8_ok" != "yes"],
[critic_missing="$critic_missing POWER8 or newer is required on powerpc64le."])
CFLAGS="$OLD_CFLAGS"
+# Local configure fragment for sysdeps/powerpc/powerpc64le.
+
+dnl Require support for -mno-gnu-attribute
+OLD_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -mno-gnu-attribute"
+AC_CACHE_CHECK([if the compiler supports -mno-gnu-attribute],
+ libc_cv_no_gnu_attr_ok, [
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+]])],
+ [libc_cv_no_gnu_attr_ok=yes],
+ [libc_cv_no_gnu_attr_ok=no])])
+AS_IF([test "$libc_cv_no_gnu_attr_ok" != "yes"],
+ [critic_missing="$critic_missing A compiler with -mno-gnu-attribute is required on powerpc64le."])
+CFLAGS="$OLD_CFLAGS"
+
test -n "$critic_missing" && AC_MSG_ERROR([*** $critic_missing])
From: "Gabriel F. T. Gomes" <gabrielftg@linux.ibm.com> On powerpc64le, a few files are built on IEEE long double mode (-mabi=ieeelongdouble), whereas most are built on IBM long double mode (-mabi=ibmlongdouble, the default for -mlong-double-128). Since binutils 2.31, linking object files with different long double modes causes errors similar to: ld: libc_pic.a(s_isinfl.os) uses IBM long double, libc_pic.a(ieee128-qefgcvt.os) uses IEEE long double. collect2: error: ld returned 1 exit status make[2]: *** [../Makerules:649: libc_pic.os] Error 1 The warnings are fair and correct, but in order for glibc to have support for both long double modes on powerpc64le, they have to be ignored. This can be accomplished with the use of -mno-gnu-attribute option when building the few files that require IEEE long double mode. However, -mno-gnu-attribute is not available in GCC 6, the minimum version required to build glibc, so this patch adds a test for this feature in powerpc64le builds, and fails early if it's not available. Tested, on powerpc64le, that the build fails early with GCC 6 and that it succeeds with GCC 7 or greater. --- sysdeps/powerpc/powerpc64/le/configure | 29 +++++++++++++++++++++++ sysdeps/powerpc/powerpc64/le/configure.ac | 15 ++++++++++++ 2 files changed, 44 insertions(+)