1 files changed, 149 insertions, 0 deletions
diff --git a/m4/fopen.m4 b/m4/fopen.m4
new file mode 100644
index 0000000..50767f8
--- /dev/null
+++ b/m4/fopen.m4
@@ -0,0 +1,149 @@
+# fopen.m4 serial 13
+dnl Copyright (C) 2007-2022 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_FOPEN],
+[
+  AC_REQUIRE([gl_STDIO_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  case "$host_os" in
+    mingw* | pw*)
+      dnl Replace fopen, for handling of "/dev/null".
+      REPLACE_FOPEN=1
+      dnl fopen on mingw also has the trailing slash bug.
+      gl_cv_func_fopen_slash="guessing no"
+      ;;
+    *)
+      dnl fopen("foo/", "w") should not create a file when the file name has a
+      dnl trailing slash.
+      AC_CACHE_CHECK([whether fopen recognizes a trailing slash],
+        [gl_cv_func_fopen_slash],
+        [
+          AC_RUN_IFELSE(
+            [AC_LANG_SOURCE([[
+#include <stddef.h>
+#include <stdio.h>
+int main ()
+{
+  FILE *fp = fopen ("conftest.sl/", "w");
+  int result = (fp != NULL);
+  if (fp != NULL)
+    fclose (fp);
+  return result;
+}]])],
+            [gl_cv_func_fopen_slash=yes],
+            [gl_cv_func_fopen_slash=no],
+            [
+changequote(,)dnl
+             case "$host_os" in
+               aix* | hpux* | solaris2.[0-9] | solaris2.[0-9].*)
+                 gl_cv_func_fopen_slash="guessing no" ;;
+               *)
+                 gl_cv_func_fopen_slash="guessing yes" ;;
+             esac
+changequote([,])dnl
+            ])
+          rm -f conftest.sl
+        ])
+      ;;
+  esac
+  case "$gl_cv_func_fopen_slash" in
+    *no)
+      AC_DEFINE([FOPEN_TRAILING_SLASH_BUG], [1],
+        [Define to 1 if fopen() fails to recognize a trailing slash.])
+      REPLACE_FOPEN=1
+      ;;
+  esac
+])
+
+AC_DEFUN([gl_FUNC_FOPEN_GNU],
+[
+  AC_REQUIRE([gl_FUNC_FOPEN])
+  AC_CACHE_CHECK([whether fopen supports the mode character 'x'],
+    [gl_cv_func_fopen_mode_x],
+    [rm -f conftest.x
+     AC_RUN_IFELSE(
+       [AC_LANG_SOURCE([[
+#include <stdio.h>
+#include <errno.h>
+int main ()
+{
+  FILE *fp;
+  fp = fopen ("conftest.x", "w");
+  fclose (fp);
+  fp = fopen ("conftest.x", "wx");
+  if (fp != NULL)
+    /* 'x' ignored */
+    return 1;
+  else if (errno == EEXIST)
+    return 0;
+  else
+    /* 'x' rejected */
+    return 2;
+}]])],
+       [gl_cv_func_fopen_mode_x=yes],
+       [gl_cv_func_fopen_mode_x=no],
+       [case "$host_os" in
+          # Guess yes on glibc and musl systems.
+          linux*-gnu* | gnu* | kfreebsd*-gnu | *-musl*)
+            gl_cv_func_fopen_mode_x="guessing yes" ;;
+          # If we don't know, obey --enable-cross-guesses.
+          *)
+            gl_cv_func_fopen_mode_x="$gl_cross_guess_normal" ;;
+        esac
+       ])
+     rm -f conftest.x
+    ])
+  AC_CACHE_CHECK([whether fopen supports the mode character 'e'],
+    [gl_cv_func_fopen_mode_e],
+    [echo foo > conftest.x
+     AC_RUN_IFELSE(
+       [AC_LANG_SOURCE([[
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+]GL_MDA_DEFINES[
+int main ()
+{
+  FILE *fp = fopen ("conftest.x", "re");
+  if (fp != NULL)
+    {
+      if (fcntl (fileno (fp), F_GETFD) & FD_CLOEXEC)
+        return 0;
+      else
+        /* 'e' ignored */
+        return 1;
+    }
+  else
+    /* 'e' rejected */
+    return 2;
+}]])],
+       [gl_cv_func_fopen_mode_e=yes],
+       [gl_cv_func_fopen_mode_e=no],
+       [case "$host_os" in
+          # Guess yes on glibc and musl systems.
+          linux*-gnu* | gnu* | kfreebsd*-gnu | *-musl*)
+            gl_cv_func_fopen_mode_e="guessing yes" ;;
+          # Guess no on native Windows.
+          mingw*)
+            gl_cv_func_fopen_mode_e="guessing no" ;;
+          # If we don't know, obey --enable-cross-guesses.
+          *)
+            gl_cv_func_fopen_mode_e="$gl_cross_guess_normal" ;;
+        esac
+       ])
+     rm -f conftest.x
+    ])
+  REPLACE_FOPEN_FOR_FOPEN_GNU="$REPLACE_FOPEN"
+  case "$gl_cv_func_fopen_mode_x" in
+    *no) REPLACE_FOPEN_FOR_FOPEN_GNU=1 ;;
+  esac
+  case "$gl_cv_func_fopen_mode_e" in
+    *no) REPLACE_FOPEN_FOR_FOPEN_GNU=1 ;;
+  esac
+])
+
+# Prerequisites of lib/fopen.c.
+AC_DEFUN([gl_PREREQ_FOPEN], [:])