Implement basic __is_trivial type-trait support, enough to close PR9472.

This introduces a few APIs on the AST to bundle up the standard-based
logic so that programmatic clients have access to exactly the same
behavior.

There is only one serious FIXME here: checking for non-trivial move
constructors and move assignment operators. Those bits need to be added
to the declaration and accessors provided.

This implementation should be enough for the uses of __is_trivial in
libstdc++ 4.6's C++98 library implementation.

Ideas for more thorough test cases or any edge cases missing would be
appreciated. =D

llvm-svn: 130057

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp
index 64b0baf3832..0e38e39c26a 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -590,6 +590,7 @@ static bool HasFeature(const Preprocessor &PP, const IdentifierInfo *II) {
            .Case("is_literal", LangOpts.CPlusPlus)
            .Case("is_pod", LangOpts.CPlusPlus)
            .Case("is_polymorphic", LangOpts.CPlusPlus)
+           .Case("is_trivial", LangOpts.CPlusPlus)
            .Case("is_union", LangOpts.CPlusPlus)
            .Case("tls", PP.getTargetInfo().isTLSSupported())
            .Default(false);