Rework configure script

[deliverable/lttng-ust.git] / m4 / rw_prog_cxx_works.m4

diff --git a/m4/rw_prog_cxx_works.m4 b/m4/rw_prog_cxx_works.m4
new file mode 100644 (file)
index 0000000..086af25
--- /dev/null
+++ b/m4/rw_prog_cxx_works.m4
@@ -0,0 +1,36 @@
+# rw_PROG_CXX_WORKS
+#
+# Check whether the C++ compiler works. There's a bit of oversight in
+# autoconf that will set the C++ compiler to g++ if no compiler is found,
+# even if g++ is not present! So we need an extra test to make sure that
+# the compiler works.
+#
+AC_DEFUN([rw_PROG_CXX_WORKS], [
+AC_REQUIRE([AC_PROG_CXX])
+AC_CACHE_CHECK([whether the C++ compiler works],
+       [rw_cv_prog_cxx_works],
+       [AC_LANG_PUSH([C++])
+
+       AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])], [
+               check_cxx_designated_initializers=yes
+       ], [
+               rw_cv_prog_cxx_works=no
+       ])
+
+       AS_IF([test "x$check_cxx_designated_initializers" = "xyes"], [
+               AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+                       struct foo { int a; int b; };
+                       void fct(void)
+                       {
+                               struct foo f = { .a = 0, .b = 1 };
+                       }
+               ]])], [
+                       rw_cv_prog_cxx_works=yes
+               ], [
+                       rw_cv_prog_cxx_works=no
+               ])
+       ])
+
+       AC_LANG_POP([C++])
+])
+])