Add static assert to ID Table to make sure aux targets work right.

I discovered that the limit on possible builtins managed by this
ObjCOrBuiltin variable is too low when combining large targets, since
aux-targets are appended to the targets list. A runtime assert exists
for this, however this patch creates a static-assert as well.

The logic for said static-assert is to make sure we have the room for
the aux-target and target to both be the largest list, which makes sure
we have room for all possible combinations.

I also incremented the number of bits by 1, since I discovered this
currently broken.  The current bit-count was 36, so this doesn't
increase any size.

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/Basic/IdentifierTable.cpp b/clang/lib/Basic/IdentifierTable.cpp
index d7ef159..36b26d9 100644
--- a/clang/lib/Basic/IdentifierTable.cpp
+++ b/clang/lib/Basic/IdentifierTable.cpp
@@ -16,6 +16,7 @@
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/OperatorKinds.h"
 #include "clang/Basic/Specifiers.h"
+#include "clang/Basic/TargetBuiltins.h"
 #include "clang/Basic/TokenKinds.h"
 #include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/FoldingSet.h"
@@ -32,6 +33,12 @@
 
 using namespace clang;
 
+// A check to make sure the ObjCOrBuiltinID has sufficient room to store the
+// largest possible target/aux-target combination. If we exceed this, we likely
+// need to just change the ObjCOrBuiltinIDBits value in IdentifierTable.h.
+static_assert(2 * LargestBuiltinID < (2 << (ObjCOrBuiltinIDBits - 1)),
+              "Insufficient ObjCOrBuiltinID Bits");
+
 //===----------------------------------------------------------------------===//
 // IdentifierTable Implementation
 //===----------------------------------------------------------------------===//