[PATCH] D137107: Allow MS extension: support of constexpr with __declspec(dllimport).

[Eli Friedman via Phabricator via cfe-commits]

efriedma added inline comments.


================
Comment at: clang/lib/CodeGen/CodeGenModule.cpp:5006
+    if (NeedsGlobalCtor || NeedsGlobalDtor)
+      DelayedCXXInitPosition[D] = ~0U;
+  } else {
----------------
zahiraam wrote:
> efriedma wrote:
> > zahiraam wrote:
> > > Do you agree this should be done only when one of those flags is on?
> > Yes, that's fine; I wasn't really paying close attention to the exact code.  Just wanted to make the point about the structure of the if statements, and code was the easiest way to explain it.
> > 
> > Maybe the outer if statement should actually be `if (isStaticInit(D, getLangOpts()) && NeedsGlobalCtor) {`.
> > 
> > On a related note, we might want to avoid the name "ctor", in case that accidentally conflicts with some user code; an "__"-prefixed name would be appropriate.
> >> Maybe the outer if statement should actually be if (isStaticInit(D, getLangOpts()) && NeedsGlobalCtor) {
> Not sure about that! There are cases where (isStaticInit(D, getLangOpts())) = true and NeedsGlobalCtor=false, but NeedsGlobalDtor=true. In which case a __dtor needs to be emitted, no?
> 
> Writing the condition as you are proposing would actually not get me into the body to emit the __dtor. Is that what we want?
EmitCXXGlobalVarDeclInitFunc should be able to handle that case.

Looking again, I'm a little concerned that in the isStaticInit() case, we're skipping a bunch of the logic in EmitCXXGlobalVarDeclInitFunc. EmitCXXCtorInit handles the basic cases correctly, but there are a lot of special cases in EmitCXXGlobalVarDeclInitFunc.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D137107/new/

https://reviews.llvm.org/D137107