1 files changed, 31 insertions, 0 deletions
diff --git a/autoconf/ast_c_declare_check.m4 b/autoconf/ast_c_declare_check.m4
new file mode 100644
index 000000000..89fb8063d
--- /dev/null
+++ b/autoconf/ast_c_declare_check.m4
@@ -0,0 +1,31 @@
+# Check if a given symbol is declared using a certain header.
+# Check whether SYMBOL (a function, variable, or constant) is declared.
+
+# AST_C_DECLARE_CHECK([package], [symbol], [header file], [version])
+AC_DEFUN([AST_C_DECLARE_CHECK],
+[
+    if test "x${PBX_$1}" != "x1" -a "${USE_$1}" != "no"; then
+        AC_MSG_CHECKING([for $2 declared 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)
+                                    (void) $2;
+                                #endif
+                                ])],
+            [   AC_MSG_RESULT(yes)
+                PBX_$1=1
+                AC_DEFINE([HAVE_$1], 1, [Define if your system has $2 declared.])
+                m4_ifval([$4], [AC_DEFINE([HAVE_$1_VERSION], $4, [Define $1 headers version])])
+            ],
+            [   AC_MSG_RESULT(no) ] 
+        )
+
+        CPPFLAGS="${saved_cppflags}"
+    fi
+])