[cfe-dev] _Unwind_Exception use by libcxxabi on linux

[Jeffrey Yasskin]

Trying to compile libcxxabi on Linux, I get:

In file included from ../src/cxa_exception.cpp:21:
../src/cxa_exception.hpp:63:9: error: unknown type name '_Unwind_Exception'

It looks like on Darwin, clang's unwind.h forwards to
/usr/include/unwind.h, which defines _Unwind_Exception. However, on
linux (ubuntu 11.10), unwind.h does not forward to
/usr/lib/gcc/x86_64-linux-gnu/4.6/include/unwind.h where
_Unwind_Exception is defined.
/usr/lib/gcc/x86_64-linux-gnu/4.6/include/ is also not on clang's
default search path on linux, probably to avoid including files like
*intrin.h that live there.

Is the right fix to copy _Unwind_Exception from darwin's unwind.h into
clang's unwind.h? Provide it from libcxxabi? Something else?

Jeffrey