Configure: if we compile with clang, check that it is not broken

[oota-llvm.git] / autoconf / configure.ac

diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index 102147c4f2c631a623e3eb8e5336483877a0dcd6..a1426c1832d56d2c6a9d9ea4347711b7cca35c2f 100644 (file)
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -65,6 +65,32 @@ AC_PROG_CC(clang llvm-gcc gcc)
 AC_PROG_CXX(clang++ llvm-g++ g++)
 AC_PROG_CPP
 
+dnl If CXX is Clang, check that it can find and parse C++ standard library
+dnl headers.
+if test "$CXX" = "clang++" ; then
+  AC_MSG_CHECKING([whether clang works])
+  AC_LANG_PUSH([C++])
+  dnl Note that space between 'include' and '(' is required.  There's a broken
+  dnl regex in aclocal that otherwise will think that we call m4's include
+  dnl builtin.
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <limits>
+#if __has_include (<cxxabi.h>)
+#include <cxxabi.h>
+#endif
+#if __has_include (<unwind.h>)
+#include <unwind.h>
+#endif
+]])],
+[
+  AC_MSG_RESULT([yes])
+],
+[
+  AC_MSG_RESULT([no])
+  AC_MSG_ERROR([Selected compiler could not find or parse C++ standard library headers.  Rerun with CC=c-compiler CXX=c++-compiler ./configure ...])
+])
+  AC_LANG_POP([C++])
+fi
+
 dnl Configure all of the projects present in our source tree. While we could
 dnl just AC_CONFIG_SUBDIRS on the set of directories in projects that have a
 dnl configure script, that usage of the AC_CONFIG_SUBDIRS macro is deprecated.