[glibc/azanella/clang] Only use -finput-charset=ascii iff compiler supports it

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=8cef1306f3f6dc2babcbb86ca343dbb347052024

commit 8cef1306f3f6dc2babcbb86ca343dbb347052024
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Fri Mar 25 13:58:03 2022 -0300

    Only use -finput-charset=ascii iff compiler supports it

Diff:
---
 Makefile                           |  2 ++
 Rules                              |  2 ++
 configure                          | 22 ++++++++++++++++++++++
 configure.ac                       | 10 ++++++++++
 intl/Makefile                      |  3 ++-
 scripts/check-installed-headers.sh | 12 +++++++++---
 6 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index b1454882bd..d520abf9dd 100644
--- a/Makefile
+++ b/Makefile
@@ -543,6 +543,7 @@ $(objpfx)check-installed-headers-c.out: \
     scripts/check-installed-headers.sh $(headers)
 	$(SHELL) $(..)scripts/check-installed-headers.sh c \
 	  "$(CC) $(filter-out -std=%,$(CFLAGS)) -D_ISOMAC $(+includes)" \
+	  $(config-cflags-charset-ascii) \
 	  $(headers) > $@; \
 	$(evaluate-test)
 
@@ -553,6 +554,7 @@ $(objpfx)check-installed-headers-cxx.out: \
     scripts/check-installed-headers.sh $(headers)
 	$(SHELL) $(..)scripts/check-installed-headers.sh c++ \
 	  "$(CXX) $(filter-out -std=%,$(CXXFLAGS)) -D_ISOMAC $(+includes)" \
+	  $(config-cflags-charset-ascii) \
 	  $(headers) > $@; \
 	$(evaluate-test)
 endif # $(CXX)
diff --git a/Rules b/Rules
index ac9455d6a7..91cf297aa5 100644
--- a/Rules
+++ b/Rules
@@ -90,6 +90,7 @@ $(objpfx)check-installed-headers-c.out: \
     $(..)scripts/check-installed-headers.sh $(headers)
 	$(SHELL) $(..)scripts/check-installed-headers.sh c \
 	  "$(CC) $(filter-out -std=%,$(CFLAGS)) -D_ISOMAC $(+includes)" \
+	  $(config-cflags-charset-ascii) \
 	  $(headers) > $@; \
 	$(evaluate-test)
 
@@ -102,6 +103,7 @@ $(objpfx)check-installed-headers-cxx.out: \
     $(..)scripts/check-installed-headers.sh $(headers)
 	$(SHELL) $(..)scripts/check-installed-headers.sh c++ \
 	  "$(CXX) $(filter-out -std=%,$(CXXFLAGS)) -D_ISOMAC $(+includes)" \
+	  $(config-cflags-charset-ascii) \
 	  $(headers) > $@; \
 	$(evaluate-test)
 endif # $(CXX)
diff --git a/configure b/configure
index 2f60e8dc66..6abcd4f479 100755
--- a/configure
+++ b/configure
@@ -6782,6 +6782,28 @@ $as_echo "$libc_cv_cc_trampoline" >&6; }
 config_vars="$config_vars
 have-cc-trampoline = $libc_cv_cc_trampoline"
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if $CC supports -finput-charset=ascii" >&5
+$as_echo_n "checking if $CC supports -finput-charset=ascii... " >&6; }
+if ${libc_cv_cc_charset_ascii+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if { ac_try='${CC-cc} -Werror -finput-charset=ascii -xc /dev/null -S -o /dev/null'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }; then :
+  libc_cv_cc_charset_ascii=yes
+else
+  libc_cv_cc_charset_ascii=no
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_cc_charset_ascii" >&5
+$as_echo "$libc_cv_cc_charset_ascii" >&6; }
+config_vars="$config_vars
+config-cflags-charset-ascii = $libc_cv_cc_charset_ascii"
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for libgd" >&5
 $as_echo_n "checking for libgd... " >&6; }
 if test "$with_gd" != "no"; then
diff --git a/configure.ac b/configure.ac
index 966e12af76..3024e72cb9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1741,6 +1741,16 @@ rm -f conftest*])
 LIBC_CONFIG_VAR([have-cc-trampoline],
 		[$libc_cv_cc_trampoline])
 
+dnl Check if -finput-charset accepts ascii
+AC_CACHE_CHECK([if $CC supports -finput-charset=ascii],
+	       libc_cv_cc_charset_ascii, [dnl
+LIBC_TRY_CC_OPTION([-Werror -finput-charset=ascii],
+		   [libc_cv_cc_charset_ascii=yes],
+		   [libc_cv_cc_charset_ascii=no])
+])
+LIBC_CONFIG_VAR([config-cflags-charset-ascii],
+		[$libc_cv_cc_charset_ascii])
+
 dnl Check whether we have the gd library available.
 AC_MSG_CHECKING(for libgd)
 if test "$with_gd" != "no"; then
diff --git a/intl/Makefile b/intl/Makefile
index 315c75a18f..1c3b2a2273 100644
--- a/intl/Makefile
+++ b/intl/Makefile
@@ -154,7 +154,8 @@ $(objpfx)tst-gettext5.out: $(objpfx)tst-gettext.out
 $(objpfx)tst-gettext6.out: $(objpfx)tst-gettext.out
 
 CPPFLAGS += -D'LOCALEDIR="$(localedir)"' \
-	    -D'LOCALE_ALIAS_PATH="$(localedir)"'
+	    -D'LOCALE_ALIAS_PATH="$(localedir)"' \
+	    -Wno-unused-but-set-variable
 BISONFLAGS = --yacc --no-lines --name-prefix=__gettext --output
 
 $(inst_localedir)/locale.alias: locale.alias $(+force)
diff --git a/scripts/check-installed-headers.sh b/scripts/check-installed-headers.sh
index 0876d2643a..457902d3b4 100644
--- a/scripts/check-installed-headers.sh
+++ b/scripts/check-installed-headers.sh
@@ -29,8 +29,8 @@ cxx_modes="-std=c++98 -std=gnu++98 -std=c++11 -std=gnu++11"
 # These are probably the most commonly used three.
 lib_modes="-D_DEFAULT_SOURCE=1 -D_GNU_SOURCE=1 -D_XOPEN_SOURCE=700"
 
-if [ $# -lt 3 ]; then
-    echo "usage: $0 c|c++ \"compile command\" header header header..." >&2
+if [ $# -lt 4 ]; then
+    echo "usage: $0 c|c++ \"compile command\" \"yes|no\" header header header..." >&2
     exit 2
 fi
 case "$1" in
@@ -49,6 +49,12 @@ esac
 shift
 cc_cmd="$1"
 shift
+if [ "$1" = "yes" ]; then
+     finputcharset="-finput-charset=ascii"
+else
+     finputcharset=""
+fi
+shift
 trap "rm -f '$cih_test_c'" 0
 
 failed=0
@@ -118,7 +124,7 @@ $expanded_lib_mode
 #include <$header>
 int avoid_empty_translation_unit;
 EOF
-            if $cc_cmd -finput-charset=ascii -fsyntax-only $lang_mode \
+            if $cc_cmd $finputcharset -fsyntax-only $lang_mode \
 		       "$cih_test_c" 2>&1
             then :
             else failed=1