[RFC/PATCH] autoconf: Use autoconf to check for some types and library functions

[Jakub Narebski <jnareb@gmail.com>]

./configure script checks now for existence of the following types
and structure members:
 * dirent.d_ino  in dirent.h (NO_D_INO_IN_DIRENT)
 * dirent.d_type in dirent.h (NO_D_TYPE_IN_DIRENT)
 * 'struct sockaddr_storage' in netinet/in.h (NO_SOCKADDR_STORAGE)

./configure script checks now for the following library functions:
 * strcasestr (NO_STRCASESTR)
 * strlcpy (NO_STRLCPY)
 * setenv (NO_SETENV)
in default C library and in libraries which have AC_CHECK_LIB done for
them (crypto, curl, expat).

NOTE: not all checks are implemented!

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
---

This patch needs review by someone better versed in compiling git on
different platforms, namely AC_CHECK_MEMBER and AC_CHECK_TYPE needs
checking if all header files where git search for specified structure
member or specified type.

I don't know (yet) how to implement checking for NEEDS_SSL_WITH_CRYPTO
(probably also checlking for crypto library needs correction),
NEEDS_LIBICONV, NEEDS_SOCKET, NO_IPV6, NO_ICONV, Python < 2.3 and
Python == 2.3, if to check for NO_MMAP, and for NO_ACCURATE_DIFF.

This patch is to be considered preliminary!

 configure.ac |   28 ++++++++++++++++++++++++++--
 1 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 55d7a9b..fbd46e2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -14,17 +14,41 @@ AC_CONFIG_SRCDIR([git.c])
 AC_DEFUN([MY_APPEND_LINE],
 [[echo "$1" >> config.mak.append]])# AC_APPEND_LINE
 
+
 # Checks for libraries.
-AC_MSG_NOTICE(CHECKS for libraries)
+AC_MSG_NOTICE([CHECKS for libraries])
 AC_CHECK_LIB([crypto], [SHA1_Init],,MY_APPEND_LINE(NO_OPENSSL=YesPlease))
 AC_CHECK_LIB([curl], [curl_easy_setopt],,MY_APPEND_LINE(NO_CURL=YesPlease))
 AC_CHECK_LIB([expat], [XML_ParserCreate],,MY_APPEND_LINE(NO_EXPAT=YesPlease))
 
+
+# Checks for typedefs, structures, and compiler characteristics.
+AC_MSG_NOTICE([CHECKS for typedefs, structures, and compiler characteristics])
+
+AC_CHECK_MEMBER(struct dirent.d_ino,,
+MY_APPEND_LINE(NO_D_INO_IN_DIRENT=YesPlease),
+[#include <dirent.h>])
+AC_CHECK_MEMBER(struct dirent.d_type,,
+MY_APPEND_LINE(NO_D_TYPE_IN_DIRENT=YesPlease),
+[#include <dirent.h>])
+
+AC_CHECK_TYPE(struct sockaddr_storage,,
+MY_APPEND_LINE(NO_SOCKADDR_STORAGE=YesPlease),
+[#include <netinet/in.h>])
+
+
+# Checks for library functions.
+AC_MSG_NOTICE([CHECKS for library functions])
+AC_CHECK_FUNC(strcasestr,,MY_APPEND_LINE(NO_STRCASESTR=YesPlease))
+AC_CHECK_FUNC(strlcpy,,MY_APPEND_LINE(NO_STRLCPY=YesPlease))
+AC_CHECK_FUNC(setenv,,MY_APPEND_LINE(NO_SETENV=YesPlease))
+
+
 # Output files
 AC_CONFIG_FILES([config.mak:config.mak.in:config.mak.append], 
 [rm -f config.mak.append], 
-- 
1.4.0