[PATCH] D77028: [NFC] Refactor DeferredDiagsEmitter and skip redundant visit

[John McCall via Phabricator via cfe-commits]

rjmccall added inline comments.


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Comment at: clang/lib/Sema/Sema.cpp:1508
   void checkFunc(SourceLocation Loc, FunctionDecl *FD) {
+    auto DiagsCountIt = DiagsCount.find(FD);
     FunctionDecl *Caller = UseStack.empty() ? nullptr : UseStack.back();
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yaxunl wrote:
> rjmccall wrote:
> > It makes me a little uncomfortable to be holding an iterator this long while calling a fair amount of other stuff in the meantime.
> > 
> > Your use of DiagsCount is subtle enough that it really needs to be explained in some comments.  You're doing stuff conditionally based on both whether the entry exists but also whether it's non-zero.
> added comments
Okay, thanks for that.  Two points, then.  First, it looks like the count is really just a boolean for whether the function recursively triggers any diagnostics.   And second, can't it just be as simple as whether we've visited that function at all in a context that's forcing diagnostics to be emitted?  The logic seems to be to try to emit the diagnostics for each use-path, but why would we want that?


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Comment at: clang/lib/Sema/Sema.cpp:1553
     if (!Caller)
       ShouldEmit = IsKnownEmitted;
     if ((!ShouldEmit && !S.getLangOpts().OpenMP && !Caller) ||
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This becomes global state for the visitor; that doesn't seem like it can be right.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D77028/new/

https://reviews.llvm.org/D77028