treaded-resolver: better error messages

Now use gai_strerror() to get proper error messages when getaddrinfo()
has failed. Detect the function in configure.

Code based on work and suggestions by Jeff Pohlmeyer and Guenter Knauf

1 files changed, 94 insertions, 1 deletions

diff --git a/m4/curl-functions.m4 b/m4/curl-functions.m4
index 6067abf96..ec57b5423 100644
--- a/m4/curl-functions.m4
+++ b/m4/curl-functions.m4
@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2010, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # This software is licensed as described in the file COPYING, which
 # you should have received as part of this distribution. The terms
@@ -2314,6 +2314,99 @@ AC_DEFUN([CURL_CHECK_FUNC_GETHOSTBYADDR], [
   fi
 ])
 
+dnl CURL_CHECK_FUNC_GAI_STRERROR
+dnl -------------------------------------------------
+dnl Verify if gai_strerror is available, prototyped,
+dnl and can be compiled. If all of these are true,
+dnl and usage has not been previously disallowed with
+dnl shell variable curl_disallow_gai_strerror, then
+dnl HAVE_GAI_STRERROR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GAI_STRERROR], [
+  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CURL_INCLUDES_NETDB])dnl
+  #
+  tst_links_gai_strerror="unknown"
+  tst_proto_gai_strerror="unknown"
+  tst_compi_gai_strerror="unknown"
+  tst_allow_gai_strerror="unknown"
+  #
+  AC_MSG_CHECKING([if gai_strerror can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_winsock2
+      $curl_includes_netdb
+    ]],[[
+      if(0 != gai_strerror(0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_gai_strerror="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_gai_strerror="no"
+  ])
+  #
+  if test "$tst_links_gai_strerror" = "yes"; then
+    AC_MSG_CHECKING([if gai_strerror is prototyped])
+    AC_EGREP_CPP([gai_strerror],[
+      $curl_includes_winsock2
+      $curl_includes_netdb
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_gai_strerror="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_gai_strerror="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_gai_strerror" = "yes"; then
+    AC_MSG_CHECKING([if gai_strerror is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+        $curl_includes_netdb
+      ]],[[
+        if(0 != gai_strerror(0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_gai_strerror="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_gai_strerror="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_gai_strerror" = "yes"; then
+    AC_MSG_CHECKING([if gai_strerror usage allowed])
+    if test "x$curl_disallow_gai_strerror" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_gai_strerror="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_gai_strerror="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if gai_strerror might be used])
+  if test "$tst_links_gai_strerror" = "yes" &&
+     test "$tst_proto_gai_strerror" = "yes" &&
+     test "$tst_compi_gai_strerror" = "yes" &&
+     test "$tst_allow_gai_strerror" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GAI_STRERROR, 1,
+      [Define to 1 if you have the gai_strerror function.])
+    ac_cv_func_gai_strerror="yes"
+  else
+    AC_MSG_RESULT([no])
+    ac_cv_func_gai_strerror="no"
+  fi
+])
+
 
 dnl CURL_CHECK_FUNC_GETHOSTBYADDR_R
 dnl -------------------------------------------------