[PATCH] D141451: [clang] report inlining decisions with -Wattribute-{warning|error}

[Nick Desaulniers via Phabricator via cfe-commits]

nickdesaulniers added inline comments.


================
Comment at: clang/test/Frontend/backend-attribute-error-warning-optimize.c:12
   foo(); // expected-error {{call to 'foo' declared with 'error' attribute: oh no foo}}
+         // expected-note@* {{In function 'baz'}}
   if (x())
----------------
cjdb wrote:
> aaron.ballman wrote:
> > nickdesaulniers wrote:
> > > nickdesaulniers wrote:
> > > > aaron.ballman wrote:
> > > > > Instead of allowing this note to appear anywhere in the file, I think it's better to use "bookmark" comments. e.g.,
> > > > > ```
> > > > > void baz() { // #baz_defn
> > > > > }
> > > > > 
> > > > > void foo() {
> > > > >   baz(); // expected-note@#baz_defn {{whatever note text}}
> > > > > }
> > > > > ```
> > > > > so that we're testing where the diagnostic is emitted. (This is especially important given that the changes are about location tracking.)
> > > > oh, that's new (to me)! will do
> > > It looks like the "bookmarks" don't work because the notes do not line+col info. They follow the warning/error diagnostic which does, on the bottom most call site.
> > > 
> > > The warning is supposed to be emitted on the callsite, not the definition.
> > I still don't think this is reasonable for test coverage because this means we'll accept the note *anywhere* in the file. This makes it much too easy to regress the behavior accidentally (e.g., accidentally emit all the notes on line 1 of the file). I think we need *some* way to nail down where these notes are emitted in the test. However, I might be asking you to solve "please track location information through the backend" for that, so perhaps this isn't a reasonable request?
> > 
> > Also, CC @cjdb for awareness of how this kind of diagnostic is produced (Chris is working on an idea for how we emit diagnostics so we get better structured information from them, so knowing about this novel approach might impact that idea).
> Very interesting, thanks for the heads up! Cross-phase diagnostics are definitely something I hadn't considered, and it **does** impact the design (but not in a derailing way).
I think we're back at "please track location information through the backend".

That is the tradeoff with this approach; not measurably regressing performance when these attributes aren't used in source in exchange for Note diagnostics that lack precise line+col info, but in practice provide enough info for the user to understand what's going wrong where.

Your call if the tradeoff is worth it.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D141451/new/

https://reviews.llvm.org/D141451