[c++20] P1143R2: Add support for the C++20 'constinit' keyword.

This is mostly the same as the
[[clang::require_constant_initialization]] attribute, but has a couple
of additional syntactic and semantic restrictions.

In passing, I added a warning for the attribute form being added after
we have already seen the initialization of the variable (but before we
see the definition); that case previously slipped between the cracks and
the attribute was silently ignored.

llvm-svn: 370972

1 files changed, 2 insertions, 0 deletions

diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index cf03ed6379c..529c09a50e7 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -1313,6 +1313,8 @@ bool Parser::isValidAfterTypeSpecifier(bool CouldBeBitfield) {
   case tok::kw_mutable:         // struct foo {...} mutable   x;
   case tok::kw_thread_local:    // struct foo {...} thread_local x;
   case tok::kw_constexpr:       // struct foo {...} constexpr x;
+  case tok::kw_consteval:       // struct foo {...} consteval x;
+  case tok::kw_constinit:       // struct foo {...} constinit x;
     // As shown above, type qualifiers and storage class specifiers absolutely
     // can occur after class specifiers according to the grammar.  However,
     // almost no one actually writes code like this.  If we see one of these,