configure: remove overly restrictive check for clang

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.

diff --git a/NEWS b/NEWS
index 244f7613d871c8cb285a3cd6771ab4ce095621fd..b4348ac51b76b27c7bd278de676fc018c0bf0ddb 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -13,6 +13,11 @@ Major new features:
 
 * The ISO C23 memalignment function has been added.
 
+* Initial support for building with clang has been added.  It requires
+  at least clang version 18, aarch64-linux-gnu or x86_64-linux-gnu
+  targets, and libgcc compatible runtime (including libgcc_s.so for
+  pthread cancellation and backtrace runtime support).
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * Support for dumped heaps has been removed - malloc_set_state() now always

diff --git a/configure b/configure
index 3c926be3ecd9ff4412f0496d72d632fd8cf9e890..a21ce56302ac851416a9cda9f88efca28cb2a6cd 100755 (executable)
--- a/configure
+++ b/configure
@@ -5799,7 +5799,7 @@ 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
   ;
@@ -7642,7 +7642,7 @@ 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'

diff --git a/configure.ac b/configure.ac
index 890f1b1c9c300d4d3644fb542aac4f7cb01bf5e6..29c45632fd1590d54601c79de0ea846ef3c19908 100644 (file)
--- 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],
@@ -1474,7 +1474,7 @@ 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