[PATCH] D46022: [OpenCL] Restrict various keywords in OpenCL C++ mode

[Sven van Haastregt via Phabricator via cfe-commits]

svenvh added inline comments.


================
Comment at: lib/Parse/ParseStmtAsm.cpp:696
+    return StmtError();
+  }
+
----------------
rjmccall wrote:
> svenvh wrote:
> > rjmccall wrote:
> > > You might consider parsing the statement normally and then just diagnosing after the fact, maybe in Sema.  You'd have to add the check in a couple different places, though.
> > Precisely the reason why I did it in the parser, otherwise we'd have to duplicate the check in multiple places.
> The downside of this is that the parser recovery is probably very bad.  But since this is asm, it's not likely to matter too much.
> 
> ...is this *also* really only an OpenCL C++ restriction?  Maybe we should read this one as a general restriction that happens to have been overlooked in the OpenCL C spec.
Yes, `asm` is only explicitly restricted in OpenCL C++.  Not sure if it's safe to assume `asm` has been overlooked for OpenCL C though, it's not explicitly forbidden so people may be using it.


================
Comment at: lib/Sema/DeclSpec.cpp:621
+    // OpenCL C++ 1.0 s2.9: the thread_local storage qualifier is not
+    // supported.
+    case TSCS_thread_local:
----------------
rjmccall wrote:
> svenvh wrote:
> > rjmccall wrote:
> > > svenvh wrote:
> > > > rjmccall wrote:
> > > > > Do you really care about the spelling of the specifier?  Presumably `__thread` (the GNU extension) and `_Thread_local` (the C11 feature) are unsupported; where are those diagnosed?
> > > > Fair enough, I have updated the patch to just reject any thread qualifier here.
> > > I meant it as a question, but I take it from this response that we don't actually diagnose these.
> > > 
> > > It might make more sense to diagnose this in `Sema::ActOnVariableDeclarator`, where we're already doing some checking about whether e.g. the target supports the feature.
> > We do actually diagnose the others in `Sema::ActOnVariableDeclarator` ("thread-local storage is not supported for the current target").  But your question made me realize there is no real need to differentiate here for the OpenCL C++ case.
> Okay.  So we can remove this code, then.
Sorry if my previous comment was ambiguous: I meant here we now reject *any* thread storage class specifier for OpenCL C++, not just the `thread_local` spelling (my original patch was only rejecting `TSCS_thread_local`).


https://reviews.llvm.org/D46022