1 files changed, 109 insertions, 0 deletions
diff --git a/m4/wctob.m4 b/m4/wctob.m4
new file mode 100644
index 0000000..90042a5
--- /dev/null
+++ b/m4/wctob.m4
@@ -0,0 +1,109 @@
+# wctob.m4 serial 13
+dnl Copyright (C) 2008-2023 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_WCTOB],
+[
+  AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
+
+  AC_CHECK_FUNCS_ONCE([wctob])
+  if test $ac_cv_func_wctob = no; then
+    HAVE_WCTOB=0
+    HAVE_DECL_WCTOB=0
+  else
+    HAVE_WCTOB=1
+
+    dnl Solaris 9 has the wctob() function but it does not work.
+    dnl Cygwin 1.7.2 has the wctob() function but it clobbers caller-owned
+    dnl registers, see <https://cygwin.com/ml/cygwin/2010-05/msg00015.html>.
+    AC_REQUIRE([AC_PROG_CC])
+    AC_REQUIRE([gt_LOCALE_FR])
+    AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+    AC_CACHE_CHECK([whether wctob works],
+      [gl_cv_func_wctob_works],
+      [
+        dnl Initial guess, used when cross-compiling or when no suitable locale
+        dnl is present.
+changequote(,)dnl
+        case "$host_os" in
+            # Guess no on Solaris <= 9 and Cygwin.
+          solaris2.[1-9] | solaris2.[1-9].* | cygwin*)
+            gl_cv_func_wctob_works="guessing no" ;;
+            # Guess no on native Windows.
+          mingw*)
+            gl_cv_func_wctob_works="guessing no" ;;
+            # Guess yes otherwise.
+          *) gl_cv_func_wctob_works="guessing yes" ;;
+        esac
+changequote([,])dnl
+        case "$host_os" in
+          cygwin*)
+            AC_RUN_IFELSE(
+              [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <wchar.h>
+
+register long global __asm__ ("%ebx");
+
+int main ()
+{
+  setlocale (LC_ALL, "en_US.UTF-8");
+
+  global = 0x12345678;
+  if (wctob (0x00FC) != -1)
+    return 1;
+  if (global != 0x12345678)
+    return 2;
+  return 0;
+}]])],
+              [:],
+              [gl_cv_func_wctob_works=no],
+              [:])
+            ;;
+        esac
+        if test "$gl_cv_func_wctob_works" != no && test $LOCALE_FR != none; then
+          AC_RUN_IFELSE(
+            [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <stdlib.h>
+#include <wchar.h>
+int main ()
+{
+  if (setlocale (LC_ALL, "$LOCALE_FR") != NULL)
+    {
+      wchar_t wc;
+
+      if (mbtowc (&wc, "\374", 1) == 1)
+        if (wctob (wc) != (unsigned char) '\374')
+          return 1;
+    }
+  return 0;
+}]])],
+            [gl_cv_func_wctob_works=yes],
+            [gl_cv_func_wctob_works=no],
+            [:])
+        fi
+      ])
+    case "$gl_cv_func_wctob_works" in
+      *yes) ;;
+      *) REPLACE_WCTOB=1 ;;
+    esac
+    if test $REPLACE_WCTOB = 0; then
+
+      dnl IRIX 6.5 has the wctob() function but does not declare it.
+      AC_CHECK_DECLS([wctob], [], [], [[
+        #include <wchar.h>
+      ]])
+      if test $ac_cv_have_decl_wctob != yes; then
+        HAVE_DECL_WCTOB=0
+      fi
+    fi
+  fi
+])
+
+# Prerequisites of lib/wctob.c.
+AC_DEFUN([gl_PREREQ_WCTOB], [
+  :
+])