[libc++] Add site config option for ABI macros
Some ABI macros affect headers, so it's nice to have a site config
option for them. Add a LIBCXX_ABI_DEFINES cmake macro to allow
specifying a list of ABI macros to define in the site config.
The primary design constraint (as discussed with Eric on IRC a while
back) was to not have to repeat the ABI macro names in cmake, which only
leaves a free-form cmake list as an option. A somewhat unfortunate
consequence is that we can't verify that the ABI macros being defined
actually exist, though we can at least perform some basic sanity
checking, since all the ABI macros begin with _LIBCPP_ABI_.
Differential Revision: https://reviews.llvm.org/D36719
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@314946 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__config_site.in b/include/__config_site.in
index 667b4e9..b8de0ba 100644
--- a/include/__config_site.in
+++ b/include/__config_site.in
@@ -24,4 +24,6 @@
#cmakedefine _LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL
#cmakedefine _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS
+@_LIBCPP_ABI_DEFINES@
+
#endif // _LIBCPP_CONFIG_SITE