X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fttyname_r.m4;h=a0308a6c35a6a141f5ff87ba4799c88af5bbe684;hb=bf552416ee94157bd9aa4045b1622234fcf28e91;hp=ce4737498d914c030bc6ca4c5447c64ed9e95952;hpb=a731808a4ac512228e870d5f443b91557f418559;p=gnulib.git

diff --git a/m4/ttyname_r.m4 b/m4/ttyname_r.m4
index ce4737498..a0308a6c3 100644
--- a/m4/ttyname_r.m4
+++ b/m4/ttyname_r.m4
@@ -1,5 +1,5 @@
-# ttyname_r.m4 serial 2
-dnl Copyright (C) 2010 Free Software Foundation, Inc.
+# ttyname_r.m4 serial 8
+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.
@@ -8,11 +8,22 @@ AC_DEFUN([gl_FUNC_TTYNAME_R],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
 
+  dnl Persuade Solaris <unistd.h> to provide the POSIX compliant declaration of
+  dnl ttyname_r().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  AC_CHECK_DECLS_ONCE([ttyname_r])
+  if test $ac_cv_have_decl_ttyname_r = no; then
+    HAVE_DECL_TTYNAME_R=0
+  fi
+
   AC_CHECK_FUNCS([ttyname_r])
   if test $ac_cv_func_ttyname_r = no; then
     HAVE_TTYNAME_R=0
   else
-    dnl On MacOS X 10.4 and Solaris 10 the return type is 'char *', not 'int'.
+    HAVE_TTYNAME_R=1
+    dnl On MacOS X 10.4 (and Solaris 10 without gl_USE_SYSTEM_EXTENSIONS)
+    dnl the return type is 'char *', not 'int'.
     AC_CACHE_CHECK([whether ttyname_r is compatible with its POSIX signature],
       [gl_cv_func_ttyname_r_posix],
       [AC_COMPILE_IFELSE(
@@ -26,12 +37,62 @@ AC_DEFUN([gl_FUNC_TTYNAME_R],
       ])
     if test $gl_cv_func_ttyname_r_posix = no; then
       REPLACE_TTYNAME_R=1
+    else
+      AC_DEFINE([HAVE_POSIXDECL_TTYNAME_R], [1],
+        [Define if the ttyname_r function has a POSIX compliant declaration.])
+      dnl On Solaris 10, both ttyname_r functions (the one with the non-POSIX
+      dnl declaration and the one with the POSIX declaration) refuse to do
+      dnl anything when the output buffer is less than 128 bytes large.
+      dnl On OSF/1 5.1, ttyname_r ignores the buffer size and assumes the
+      dnl buffer is large enough.
+      AC_REQUIRE([AC_CANONICAL_HOST])
+      AC_CACHE_CHECK([whether ttyname_r works with small buffers],
+        [gl_cv_func_ttyname_r_works],
+        [
+          dnl Initial guess, used when cross-compiling or when /dev/tty cannot
+          dnl be opened.
+changequote(,)dnl
+          case "$host_os" in
+                      # Guess no on Solaris.
+            solaris*) gl_cv_func_ttyname_r_works="guessing no" ;;
+                      # Guess no on OSF/1.
+            osf*)     gl_cv_func_ttyname_r_works="guessing no" ;;
+                      # Guess yes otherwise.
+            *)        gl_cv_func_ttyname_r_works="guessing yes" ;;
+          esac
+changequote([,])dnl
+          AC_RUN_IFELSE(
+            [AC_LANG_SOURCE([[
+#include <fcntl.h>
+#include <unistd.h>
+int
+main (void)
+{
+  int result = 0;
+  int fd;
+  char buf[31]; /* use any size < 128 here */
+
+  fd = open ("/dev/tty", O_RDONLY);
+  if (fd < 0)
+    result |= 16;
+  else if (ttyname_r (fd, buf, sizeof (buf)) != 0)
+    result |= 17;
+  else if (ttyname_r (fd, buf, 1) == 0)
+    result |= 18;
+  return result;
+}]])],
+            [gl_cv_func_ttyname_r_works=yes],
+            [case $? in
+               17 | 18) gl_cv_func_ttyname_r_works=no ;;
+             esac],
+            [:])
+        ])
+      case "$gl_cv_func_ttyname_r_works" in
+        *yes) ;;
+        *) REPLACE_TTYNAME_R=1 ;;
+      esac
     fi
   fi
-  if test $HAVE_TTYNAME_R = 0 || test $REPLACE_TTYNAME_R = 1; then
-    AC_LIBOBJ([ttyname_r])
-    gl_PREREQ_TTYNAME_R
-  fi
 ])
 
 # Prerequisites of lib/ttyname_r.c.