[PATCH] D24888: [clang-tidy] Use [[clang::suppress]] with cppcoreguidelines-pro-type-reinterpret-cast

[Aaron Ballman via cfe-commits]

aaron.ballman added inline comments.


================
Comment at: clang-tidy/cppcoreguidelines/ProTypeReinterpretCastCheck.cpp:25
 
-  Finder->addMatcher(cxxReinterpretCastExpr().bind("cast"), this);
+  std::vector<StringRef> Rules{"type", "type.1", "cppcoreguidelines-pro-type-reinterpret-cast"};
+  Finder->addMatcher(cxxReinterpretCastExpr(unless(isSuppressed(Rules))).bind("cast"), this);
----------------
malcolm.parsons wrote:
> aaron.ballman wrote:
> > mgehre wrote:
> > > aaron.ballman wrote:
> > > > Hmm, it seems like this is boilerplate we are going to want for every rule, and that it's pretty easy to not get this right (for instance, if you change the way the check is spelled, you have to remember to update this as well). Could this actually be handled more transparently, by gathering this information when the check is registered and exposing it to the check?
> > > > 
> > > > The checks would still need to use `unless(isSuppressed(Rules))` in some form, but I am thinking that it would be more convenient if we could do: `Finder->addMatcher(cxxReinterpretCastExpr(unlessSuppressed(*this)).bind("cast"), this);`
> > > I see multiple ways on how to integrate that into clang-tidy:
> > > 1) Add something like you proposed to each matcher of each check
> > > 2) Change (or add overload of)
> > > ```
> > >  DiagnosticBuilder diag(SourceLocation Loc, StringRef Description,
> > >                          DiagnosticIDs::Level Level = DiagnosticIDs::Warning);
> > > ```
> > > to add a AST node as parameter and make the SourceLocation optional. Most checks anyhow
> > > call this like diag(E->getLoc(), "...."), and then they would do diag(E, "...").
> > > Diag then would check from the that AST node upwards to see if it finds a matching [[suppress]] attribute
> > > 
> > > 3) Change the RecursiveASTVistor that drives the AST Matches to prune certain matchers from the list of to-be-evaluated matchers
> > > for all AST subtrees that are below a certain [[suppress]] attribute. (This is based on how I image that the AST matchers work)
> > Ideally, I would like to see this attribute used to suppress Clang diagnostics as well, however. So while I think Option 2 is better suited to that future direction, it's still not ideal because all instances of diag() need to be updated to take advantage. Options 1 and 3 are basically limited to clang-tidy use.
> > 
> > I wonder if there's a way to modify the diagnostic builder to transparently handle this without requiring modifying all of the call sites?
> clang-tidy reports how many warnings were suppressed by NOLINT comments.
> I'd expect the number of warnings suppressed by [[clang::suppress]] to be included in the count.
> Handling suppressions in the matchers or visitors would prevent this.
As would handling the suppression transparently within the diagnostic engine itself.


https://reviews.llvm.org/D24888