Merged revisions 151242-151243 via svnmerge from

https://origsvn.digium.com/svn/asterisk/trunk

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  r151242 | kpfleming | 2008-10-20 07:59:04 +0300 (Mon, 20 Oct 2008) | 9 lines
  
  Merged revisions 151240 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.4
  
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    r151240 | kpfleming | 2008-10-20 07:45:56 +0300 (Mon, 20 Oct 2008) | 3 lines
    
    break up acinclude.m4 into individual files, which will make it easier to maintain, easier to add new macros (less patching) and will ease maintenance of these macros across Asterisk branches
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  r151243 | kpfleming | 2008-10-20 08:00:56 +0300 (Mon, 20 Oct 2008) | 9 lines
  
  Merged revisions 151241 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.4
  
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    r151241 | kpfleming | 2008-10-20 07:57:33 +0300 (Mon, 20 Oct 2008) | 2 lines
    
    rename this macro to properly reflect what it does
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git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.0@151244 65c4cc65-6c06-0410-ace0-fbb531ad65f3

autoconf/ast_c_define_check.m4

@@ -0,0 +1,33 @@
+# Check if a given macro is defined in a certain header.
+
+# AST_C_DEFINE_CHECK([package], [macro name], [header file], [version])
+AC_DEFUN([AST_C_DEFINE_CHECK],
+[
+    if test "x${PBX_$1}" != "x1"; then
+	AC_MSG_CHECKING([for $2 in $3])
+	saved_cppflags="${CPPFLAGS}"
+	if test "x${$1_DIR}" != "x"; then
+	    $1_INCLUDE="-I${$1_DIR}/include"
+	fi
+	CPPFLAGS="${CPPFLAGS} ${$1_INCLUDE}"
+
+	AC_COMPILE_IFELSE(
+	    [ AC_LANG_PROGRAM( [#include <$3>],
+			       [#if defined($2)
+				int foo = 0;
+			        #else
+			        int foo = bar;
+			        #endif
+				0
+			       ])],
+	    [   AC_MSG_RESULT(yes)
+		PBX_$1=1
+		AC_DEFINE([HAVE_$1], 1, [Define if your system has the $1 headers.])
+		AC_DEFINE([HAVE_$1_VERSION], $4, [Define $1 headers version])
+	    ],
+	    [   AC_MSG_RESULT(no) ] 
+	)
+	CPPFLAGS="${saved_cppflags}"
+    fi
+    AC_SUBST(PBX_$1)
+])