X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fpwrite.m4;h=d4001680dd081917f21219c217c8eb9cfbd2d752;hb=39a489fa27ab3873e0fc0f65844413f46fcb2117;hp=90d8caca651cfd1e1f130680523d2b0e4f2d213d;hpb=b111537c9eeb50ded7f91beecb879f69604ce36e;p=gnulib.git

diff --git a/m4/pwrite.m4 b/m4/pwrite.m4
index 90d8caca6..d4001680d 100644
--- a/m4/pwrite.m4
+++ b/m4/pwrite.m4
@@ -1,5 +1,5 @@
-# pwrite.m4 serial 1
-dnl Copyright (C) 2010 Free Software Foundation, Inc.
+# pwrite.m4 serial 4
+dnl Copyright (C) 2010-2011 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.
@@ -7,13 +7,97 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_PWRITE],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
 
   dnl Persuade glibc <unistd.h> to declare pwrite().
   AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
 
   AC_CHECK_FUNCS_ONCE([pwrite])
-  if test $ac_cv_func_pwrite = no; then
+  if test $ac_cv_func_pwrite = yes; then
+    dnl On HP-UX 11.11 with _FILE_OFFSET_BITS=64, pwrite() on a file does not
+    dnl fail when an invalid (negative) offset is passed and uses an arbitrary
+    dnl offset instead of the argument.
+    AC_CACHE_CHECK([whether pwrite works],
+      [gl_cv_func_pwrite_works],
+      [
+        dnl Initial guess, used when cross-compiling.
+changequote(,)dnl
+        case "$host_os" in
+                 # Guess no on HP-UX.
+          hpux*) gl_cv_func_pwrite_works="guessing no" ;;
+                 # Guess yes otherwise.
+          *)     gl_cv_func_pwrite_works="guessing yes" ;;
+        esac
+changequote([,])dnl
+        gl_save_CPPFLAGS="$CPPFLAGS"
+        CPPFLAGS="$CPPFLAGS -D_FILE_OFFSET_BITS=64"
+        rm -f conftest.out
+        AC_RUN_IFELSE(
+          [AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
+             ]],
+             [[
+{
+  /* This test fails on HP-UX 11.00..11.11.  */
+  {
+    int fd = open ("conftest.out", O_RDWR | O_CREAT | O_TRUNC, 0600);
+    if (fd < 0)
+      return 1;
+    if (pwrite (fd, "b", 1, (off_t) -1) >= 0)
+      return 2;
+  }
+  /* This test fails on HP-UX 11.00..11.11.  */
+  {
+    int fd;
+    char buf[] = "01";
+
+    fd = open ("conftest.out", O_WRONLY | O_CREAT | O_TRUNC, 0600);
+    if (fd < 0)
+      return 3;
+    if (write (fd, buf, 2) < 2)
+      return 4;
+    if (close (fd) < 0)
+      return 5;
+
+    fd = open ("conftest.out", O_WRONLY, 0600);
+    if (fd < 0)
+      return 6;
+    if (pwrite (fd, "W", 1, (off_t) 0) != 1)
+      return 7;
+    if (close (fd) < 0)
+      return 8;
+
+    fd = open ("conftest.out", O_RDONLY);
+    if (fd < 0)
+      return 9;
+    if (read (fd, buf, 2) < 2)
+      return 10;
+    if (close (fd) < 0)
+      return 11;
+    if (buf[0] != 'W')
+      return 12;
+    if (buf[1] != '1')
+      return 13;
+  }
+  return 0;
+}
+
+
+  return 0;
+}]])],
+          [gl_cv_func_pwrite_works=yes],
+          [gl_cv_func_pwrite_works=no],
+          [:])
+        rm -f conftest.out
+        CPPFLAGS="$gl_save_CPPFLAGS"
+      ])
+    case "$gl_cv_func_pwrite_works" in
+      *yes) ;;
+      *) REPLACE_PWRITE=1 ;;
+    esac
+  else
     HAVE_PWRITE=0
-    AC_LIBOBJ([pwrite])
   fi
 ])