[PATCH 58/59] configure: remove overly restrictive check for clang

[Adhemerval Zanella]

The clang support is still experimental and not all testcase build
or run correctly.  Only clang 18 and onwards is supported and only
for x86_64-linux-gnu and aarch64-linux-gnu.
---
 configure    | 13 +++++--------
 configure.ac |  4 ++--
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/configure b/configure
index c8ed16bd79d..083122a5ae0 100755
--- a/configure
+++ b/configure
@@ -5800,7 +5800,7 @@ int
 main (void)
 {
 
-#if !defined __GNUC__ || __GNUC__ < 12 || (__GNUC__ == 12 && __GNUC_MINOR__ < 1)
+#if (!defined __GNUC__ || __GNUC__ < 12 || (__GNUC__ == 12 && __GNUC_MINOR__ < 1)) && (!defined __clang__ || __clang_major__ < 18)
 #error insufficient compiler
 #endif
   ;
@@ -7515,8 +7515,7 @@ $conftest_code
 EOF
 
 saved_CC="$CC"
-saved_CFLAGS="$CFLAGS"
-CC="$TEST_CC -Wno-unused-command-line-argument"
+CC="$TEST_CC"
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for traditional tls support in testing" >&5
 printf %s "checking for traditional tls support in testing... " >&6; }
 if test ${libc_cv_test_mtls_traditional+y}
@@ -7739,7 +7738,7 @@ else case e in #(
 extern char *strstr (const char *, const char *) __asm ("my_strstr");
 char *foo (const char *a, const char *b)
 {
-  return __builtin_strstr (a, b);
+  return strstr (a, b);
 }
 EOF
 if { ac_try='${CC-cc} -O3 -S conftest.c -o - | grep -F "my_strstr" > /dev/null'
@@ -8110,8 +8109,7 @@ if test "$TEST_CC" = "$CC"; then
 else
 
 saved_CC="$CC"
-saved_CFLAGS="$CFLAGS"
-CC="$TEST_CC -Wno-unused-command-line-argument"
+CC="$TEST_CC"
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for -Wfree-labels in testing" >&5
 printf %s "checking for -Wfree-labels in testing... " >&6; }
 if test ${libc_cv_test_cc_wfree_labels+y}
@@ -8171,8 +8169,7 @@ if test "$TEST_CC" = "$CC"; then
 else
 
 saved_CC="$CC"
-saved_CFLAGS="$CFLAGS"
-CC="$TEST_CC -Wno-unused-command-line-argument"
+CC="$TEST_CC"
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for -Wmissing-parameter-name in testing" >&5
 printf %s "checking for -Wmissing-parameter-name in testing... " >&6; }
 if test ${libc_cv_test_cc_wmissing_parameter_name+y}
diff --git a/configure.ac b/configure.ac
index f5cbdd6bdb5..89659e905c7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -585,7 +585,7 @@ AC_CHECK_PROG_VER(BISON, bison, --version,
 # Require GCC 12.1 to build.
 AC_CACHE_CHECK([if $CC is sufficient to build libc], libc_cv_compiler_ok, [
 AC_PREPROC_IFELSE([AC_LANG_PROGRAM([[]], [[
-#if !defined __GNUC__ || __GNUC__ < 12 || (__GNUC__ == 12 && __GNUC_MINOR__ < 1)
+#if (!defined __GNUC__ || __GNUC__ < 12 || (__GNUC__ == 12 && __GNUC_MINOR__ < 1)) && (!defined __clang__ || __clang_major__ < 18)
 #error insufficient compiler
 #endif]])],
 	       [libc_cv_compiler_ok=yes],
@@ -1507,7 +1507,7 @@ cat > conftest.c <<\EOF
 extern char *strstr (const char *, const char *) __asm ("my_strstr");
 char *foo (const char *a, const char *b)
 {
-  return __builtin_strstr (a, b);
+  return strstr (a, b);
 }
 EOF
 dnl
-- 
2.43.0