Add character set related __STDC_* definitions.

Clang uses UTF-16 and UTF-32 for its char16_t's and char32_t's
exclusively. This means that we can define __STDC_UTF_16__ and
__STDC_UTF_32__ unconditionally.

While there, define __STDC_MB_MIGHT_NEQ_WC__ for FreeBSD. FreeBSD's
wchar_t's don't encode characters as ISO-10646; the encoding depends on
the locale used. Because the character set used might not be a superset
of ASCII, we must define __STDC_MB_MIGHT_NEQ_WC__.

llvm-svn: 191631

1 files changed, 5 insertions, 0 deletions

diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index f1a14544104..3ee9cd48b53 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -253,6 +253,11 @@ protected:
     Builder.defineMacro("__KPRINTF_ATTRIBUTE__");
     DefineStd(Builder, "unix", Opts);
     Builder.defineMacro("__ELF__");
+
+    // On FreeBSD, wchar_t contains the number of the code point as
+    // used by the character set of the locale. These character sets are
+    // not necessarily a superset of ASCII.
+    Builder.defineMacro("__STDC_MB_MIGHT_NEQ_WC__", "1");
   }
 public:
   FreeBSDTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {