ptsname_r: Avoid compilation error on OSF/1 5.1.

[gnulib.git] / m4 / ptsname_r.m4

diff --git a/m4/ptsname_r.m4 b/m4/ptsname_r.m4
index fb07099..695fe79 100644 (file)
--- a/m4/ptsname_r.m4
+++ b/m4/ptsname_r.m4
@@ -1,4 +1,4 @@
-# ptsname_r.m4 serial 1
+# ptsname_r.m4 serial 2
 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,
@@ -14,6 +14,33 @@ AC_DEFUN([gl_FUNC_PTSNAME_R],
   AC_CHECK_FUNCS_ONCE([ptsname_r])
   if test $ac_cv_func_ptsname_r = no; then
     HAVE_PTSNAME_R=0
+  else
+    dnl On OSF/1 5.1, the type of the third argument is 'int', not 'size_t',
+    dnl and the declaration is missing if _REENTRANT is not defined.
+    AC_CACHE_CHECK([whether ptsname_r has the same signature as in glibc],
+      [gl_cv_func_ptsname_r_signature_ok],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[#include <stddef.h>
+              #include <stdlib.h>
+              /* Test whether ptsname_r is declared at all.  */
+              int (*f) (int, char *, size_t) = ptsname_r;
+              /* Test whether it has the same declaration as in glibc.  */
+              #undef ptsname_r
+              extern
+              #ifdef __cplusplus
+              "C"
+              #endif
+              int ptsname_r (int, char *, size_t);
+            ]],
+            [[return f (0, NULL, 0);]])
+         ],
+         [gl_cv_func_ptsname_r_signature_ok=yes],
+         [gl_cv_func_ptsname_r_signature_ok=no])
+      ])
+    if test $gl_cv_func_ptsname_r_signature_ok = no; then
+      REPLACE_PTSNAME_R=1
+    fi
   fi
 ])