Imported Upstream version 1.4.19

[platform/upstream/m4.git] / m4 / fcntl.m4

diff --git a/m4/fcntl.m4 b/m4/fcntl.m4
index a93ed85..f626434 100644 (file)
--- a/m4/fcntl.m4
+++ b/m4/fcntl.m4
@@ -1,5 +1,5 @@
-# fcntl.m4 serial 4
-dnl Copyright (C) 2009-2011 Free Software Foundation, Inc.
+# fcntl.m4 serial 11
+dnl Copyright (C) 2009-2021 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.
@@ -27,20 +27,52 @@ AC_DEFUN([gl_FUNC_FCNTL],
     dnl haiku alpha 2 F_DUPFD has wrong errno
     AC_CACHE_CHECK([whether fcntl handles F_DUPFD correctly],
       [gl_cv_func_fcntl_f_dupfd_works],
-      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
-#include <fcntl.h>
-#include <errno.h>
-]], [[int result = 0;
-      if (fcntl (0, F_DUPFD, -1) != -1) result |= 1;
-      if (errno != EINVAL) result |= 2;
-      return result;
-         ]])],
+      [AC_RUN_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[#include <errno.h>
+              #include <fcntl.h>
+              #include <limits.h>
+              #include <sys/resource.h>
+              #include <unistd.h>
+              ]GL_MDA_DEFINES[
+              #ifndef RLIM_SAVED_CUR
+              # define RLIM_SAVED_CUR RLIM_INFINITY
+              #endif
+              #ifndef RLIM_SAVED_MAX
+              # define RLIM_SAVED_MAX RLIM_INFINITY
+              #endif
+            ]],
+            [[int result = 0;
+              int bad_fd = INT_MAX;
+              struct rlimit rlim;
+              if (getrlimit (RLIMIT_NOFILE, &rlim) == 0
+                  && 0 <= rlim.rlim_cur && rlim.rlim_cur <= INT_MAX
+                  && rlim.rlim_cur != RLIM_INFINITY
+                  && rlim.rlim_cur != RLIM_SAVED_MAX
+                  && rlim.rlim_cur != RLIM_SAVED_CUR)
+                bad_fd = rlim.rlim_cur;
+              if (fcntl (0, F_DUPFD, -1) != -1) result |= 1;
+              if (errno != EINVAL) result |= 2;
+              if (fcntl (0, F_DUPFD, bad_fd) != -1) result |= 4;
+              if (errno != EINVAL) result |= 8;
+              /* On OS/2 kLIBC, F_DUPFD does not work on a directory fd */
+              {
+                int fd;
+                fd = open (".", O_RDONLY);
+                if (fd == -1)
+                  result |= 16;
+                else if (fcntl (fd, F_DUPFD, STDERR_FILENO + 1) == -1)
+                  result |= 32;
+
+                close (fd);
+              }
+              return result;]])],
          [gl_cv_func_fcntl_f_dupfd_works=yes],
          [gl_cv_func_fcntl_f_dupfd_works=no],
-         [# Guess that it works on glibc systems
-          case $host_os in #((
-            *-gnu*) gl_cv_func_fcntl_f_dupfd_works="guessing yes";;
-            *)      gl_cv_func_fcntl_f_dupfd_works="guessing no";;
+         [case $host_os in
+            aix* | cygwin* | haiku*)
+               gl_cv_func_fcntl_f_dupfd_works="guessing no" ;;
+            *) gl_cv_func_fcntl_f_dupfd_works="guessing yes" ;;
           esac])])
     case $gl_cv_func_fcntl_f_dupfd_works in
       *yes) ;;
@@ -49,15 +81,29 @@ AC_DEFUN([gl_FUNC_FCNTL],
           behavior does not match POSIX]) ;;
     esac
 
-    dnl Many systems lack F_DUPFD_CLOEXEC
+    dnl Many systems lack F_DUPFD_CLOEXEC.
+    dnl NetBSD 9.0 declares F_DUPFD_CLOEXEC but it works only like F_DUPFD.
     AC_CACHE_CHECK([whether fcntl understands F_DUPFD_CLOEXEC],
       [gl_cv_func_fcntl_f_dupfd_cloexec],
-      [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-#include <fcntl.h>
-#ifndef F_DUPFD_CLOEXEC
-choke me
-#endif
-         ]])],
+      [AC_RUN_IFELSE(
+         [AC_LANG_SOURCE(
+            [[#include <fcntl.h>
+              #include <unistd.h>
+              int main (int argc, char *argv[])
+              {
+                if (argc == 1)
+                  /* parent process */
+                  {
+                    if (fcntl (1, F_DUPFD_CLOEXEC, 10) < 0)
+                      return 1;
+                    return execl ("./conftest", "./conftest", "child", NULL);
+                  }
+                else
+                  /* child process */
+                  return (fcntl (10, F_GETFL) < 0 ? 0 : 42);
+              }
+            ]])
+         ],
          [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #ifdef __linux__
 /* The Linux kernel only added F_DUPFD_CLOEXEC in 2.6.24, so we always replace
@@ -66,13 +112,31 @@ choke me
 #endif
            ]])],
            [gl_cv_func_fcntl_f_dupfd_cloexec=yes],
-           [gl_cv_func_fcntl_f_dupfd_cloexec="needs runtime check"])],
-         [gl_cv_func_fcntl_f_dupfd_cloexec=no])])
-    if test "$gl_cv_func_fcntl_f_dupfd_cloexec" != yes; then
+           [gl_cv_func_fcntl_f_dupfd_cloexec="needs runtime check"])
+         ],
+         [gl_cv_func_fcntl_f_dupfd_cloexec=no],
+         [case "$host_os" in
+                     # Guess no on NetBSD.
+            netbsd*) gl_cv_func_fcntl_f_dupfd_cloexec="guessing no" ;;
+            *)       gl_cv_func_fcntl_f_dupfd_cloexec="$gl_cross_guess_normal" ;;
+          esac
+         ])
+      ])
+    case "$gl_cv_func_fcntl_f_dupfd_cloexec" in
+      *yes) ;;
+      *)    gl_REPLACE_FCNTL
+            dnl No witness macro needed for this bug.
+            ;;
+    esac
+  fi
+  dnl Replace fcntl() for supporting the gnulib-defined fchdir() function,
+  dnl to keep fchdir's bookkeeping up-to-date.
+  m4_ifdef([gl_FUNC_FCHDIR], [
+    gl_TEST_FCHDIR
+    if test $HAVE_FCHDIR = 0; then
       gl_REPLACE_FCNTL
-      dnl No witness macro needed for this bug.
     fi
-  fi
+  ])
 ])
 
 AC_DEFUN([gl_REPLACE_FCNTL],
@@ -84,5 +148,4 @@ AC_DEFUN([gl_REPLACE_FCNTL],
   else
     REPLACE_FCNTL=1
   fi
-  AC_LIBOBJ([fcntl])
 ])