add dependencies needed by gnulib-tool

[gnulib.git] / lib / pipe2.c

diff --git a/lib/pipe2.c b/lib/pipe2.c
index 805c3f5..7def1b1 100644 (file)
--- a/lib/pipe2.c
+++ b/lib/pipe2.c
@@ -23,14 +23,48 @@
 #include <errno.h>
 #include <fcntl.h>
 
+#include "binary-io.h"
+
 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 /* Native Woe32 API.  */
 
 # include <io.h>
 
+#else
+/* Unix API.  */
+
+# ifndef O_CLOEXEC
+#  define O_CLOEXEC 0
+# endif
+
+#endif
+
 int
 pipe2 (int fd[2], int flags)
 {
+#if HAVE_PIPE2
+# undef pipe2
+  /* Try the system call first, if it exists.  (We may be running with a glibc
+     that has the function but with an older kernel that lacks it.)  */
+  {
+    /* Cache the information whether the system call really exists.  */
+    static int have_pipe2_really; /* 0 = unknown, 1 = yes, -1 = no */
+    if (have_pipe2_really >= 0)
+      {
+       int result = pipe2 (fd, flags);
+       if (!(result < 0 && errno == ENOSYS))
+         {
+           have_pipe2_really = 1;
+           return result;
+         }
+       have_pipe2_really = -1;
+      }
+  }
+#endif
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Native Woe32 API.  */
+
   /* Check the supported flags.  */
   if ((flags & ~(O_CLOEXEC | O_BINARY | O_TEXT)) != 0)
     {
@@ -39,18 +73,10 @@ pipe2 (int fd[2], int flags)
     }
 
   return _pipe (fd, 4096, flags);
-}
 
 #else
 /* Unix API.  */
 
-# ifndef O_CLOEXEC
-#  define O_CLOEXEC 0
-# endif
-
-int
-pipe2 (int fd[2], int flags)
-{
   /* Check the supported flags.  */
   if ((flags & ~(O_CLOEXEC | O_NONBLOCK | O_TEXT | O_BINARY)) != 0)
     {
@@ -87,12 +113,18 @@ pipe2 (int fd[2], int flags)
        goto fail;
     }
 
-#if O_BINARY
+# if O_BINARY
   if (flags & O_BINARY)
-    setmode (fd, O_BINARY);
+    {
+      setmode (fd[1], O_BINARY);
+      setmode (fd[0], O_BINARY);
+    }
   else if (flags & O_TEXT)
-    setmode (fd, O_TEXT);
-#endif
+    {
+      setmode (fd[1], O_TEXT);
+      setmode (fd[0], O_TEXT);
+    }
+# endif
 
   return 0;
 
@@ -104,6 +136,6 @@ pipe2 (int fd[2], int flags)
     errno = saved_errno;
     return -1;
   }
-}
 
 #endif
+}