AST representation for user-defined literals, plus just enough of semantic

analysis to make the AST representation testable. They are represented by a
new UserDefinedLiteral AST node, which is a sugared CallExpr. All semantic
properties, including full CodeGen support, are achieved for free by this
representation.

UserDefinedLiterals can never be dependent, so no custom instantiation
behavior is required. They are mangled as if they were direct calls to the
underlying literal operator. This matches g++'s apparent behavior (but not its
actual mangling, which is broken for literal-operator-ids).

User-defined *string* literals are now fully-operational, but the semantic
analysis is quite hacky and needs more work. No other forms of user-defined
literal are created yet, but the AST support for them is present.

This patch committed after midnight because we had already hit the quota for
new kinds of literal yesterday.

llvm-svn: 152211

1 files changed, 17 insertions, 5 deletions

diff --git a/clang/test/Parser/cxx11-user-defined-literals.cpp b/clang/test/Parser/cxx11-user-defined-literals.cpp
index c2d5af5c1de..e3f79ecc7cc 100644
--- a/clang/test/Parser/cxx11-user-defined-literals.cpp
+++ b/clang/test/Parser/cxx11-user-defined-literals.cpp
@@ -44,11 +44,11 @@ constexpr const char16_t operator"" _id(const char16_t *p, size_t n) { return *p
 constexpr const char32_t operator"" _id(const char32_t *p, size_t n) { return *p; }
 
 template<int n> struct S {};
-S<"a"_id[0]> sa;
-S<L"b"_id[0]> sb;
-S<u8"c"_id[0]> sc;
-S<u"d"_id[0]> sd;
-S<U"e"_id[0]> se;
+S<"a"_id> sa;
+S<L"b"_id> sb;
+S<u8"c"_id> sc;
+S<u"d"_id> sd;
+S<U"e"_id> se;
 
 S<'w'_id> sw;
 S<L'x'_id> sx;
@@ -58,3 +58,15 @@ S<U'z'_id> sz;
 void h() {
   (void)"test"_id "test" L"test";
 }
+
+enum class LitKind { CharStr, WideStr, Char16Str, Char32Str };
+constexpr LitKind operator"" _kind(const char *p, size_t n) { return LitKind::CharStr; }
+constexpr LitKind operator"" _kind(const wchar_t *p, size_t n) { return LitKind::WideStr; }
+constexpr LitKind operator"" _kind(const char16_t *p, size_t n) { return LitKind::Char16Str; }
+constexpr LitKind operator"" _kind(const char32_t *p, size_t n) { return LitKind::Char32Str; }
+
+static_assert("foo"_kind == LitKind::CharStr, "");
+static_assert(u8"foo"_kind == LitKind::CharStr, "");
+static_assert(L"foo"_kind == LitKind::WideStr, "");
+static_assert(u"foo"_kind == LitKind::Char16Str, "");
+static_assert(U"foo"_kind == LitKind::Char32Str, "");