ymandel marked 2 inline comments as done.
ymandel added inline comments.
================
Comment at: clang/include/clang/ASTMatchers/ASTMatchers.h:3300
+/// matches `x.m()` and `p->m()`.
+AST_MATCHER_P_OVERLOAD(clang::CXXMemberCallExpr, invokedAtType,
+ clang::ast_matchers::internal::Matcher<clang::QualType>,
----------------
alexfh wrote:
> ymandel wrote:
> > aaron.ballman wrote:
> > > ymandel wrote:
> > > > aaron.ballman wrote:
> > > > > aaron.ballman wrote:
> > > > > > ymandel wrote:
> > > > > > > ymandel wrote:
> > > > > > > > aaron.ballman wrote:
> > > > > > > > > alexfh wrote:
> > > > > > > > > > The name of the matcher doesn't tell me much. I had to
> > > > > > > > > > carefully read the documentation to understand what is it
> > > > > > > > > > about. I don't have a name that would raise no questions
> > > > > > > > > > and wouldn't be too verbose at the same time, but a bit of
> > > > > > > > > > verbosity wouldn't hurt I guess. How about
> > > > > > > > > > `objectTypeAsWritten`?
> > > > > > > > > Yeah, I think this would be a better name. Also, having some
> > > > > > > > > examples that demonstrate where this behavior differs from
> > > > > > > > > `thisPointerType` would be helpful.
> > > > > > > > Agreed that it needs a new name, but I'm having trouble finding
> > > > > > > > one I'm satisfied with. Here's the full description: "the type
> > > > > > > > of the written implicit object argument". I base this phrasing
> > > > > > > > on the class CXXMemberCallExpr's terminology. In `x.f(5)`, `x`
> > > > > > > > is the implicit object argument, whether or not it is also
> > > > > > > > implicitly surrounded by a cast. That is, "implicit" has two
> > > > > > > > different meanings in this context.
> > > > > > > >
> > > > > > > > So, with that, how about `writtenObjectType`? It's close to
> > > > > > > > `objectTypeAsWritten` but I'm hoping it makes more clear that
> > > > > > > > the "written" part is the object not the type.
> > > > > > > I've contrasted the behavior with thisPointerType in both of the
> > > > > > > examples. Do you think this helps or do you want something more
> > > > > > > explicit?
> > > > > > Here's a totally different direction: `onOrPointsToType()`
> > > > > > ```
> > > > > > cxxMemberCallExpr(onOrPointsToType(hasDeclaration(cxxRecordDecl(hasName("Y")))))
> > > > > > ```
> > > > > >
> > > > > I think more explicit would be better. e.g.,
> > > > > ```
> > > > > cxxMemberCallExpr(invokedAtType(hasDeclaration(cxxRecordDecl(hasName("X")))))
> > > > > matches 'x.m()' and 'p->m()'.
> > > > > cxxMemberCallExpr(on(thisPointerType(hasDeclaration(cxxRecordDecl(hasName("X"))))))
> > > > > matches nothing because the type of 'this' is 'Y' in both cases.
> > > > > ```
> > > > But, what about even simpler: onType? I think this parallels the
> > > > intuition of the name thisPointerType. onType(T) should match x.f and
> > > > x->f, where x is type T.
> > > You've pointed out why I don't think `onType` works -- it doesn't match
> > > on type T -- it matches on type T, or a pointer/reference to type T,
> > > which is pretty different. Someone reading the matcher may expect an
> > > exact type match and insert a `pointerType()` or something there thinking
> > > they need to do that to match a call through a pointer.
> > >
> > > @alexfh, opinions?
> > True. I should have explained more.
> >
> > 1. Ultimately, I think that none of these names really make sense on their
> > own and the user will need some familiarity with the documentation. I spent
> > quite a while trying to come up with better names and didn't find anything
> > compelling. I think that `onType` benefits from not carrying much
> > information -- reducing the likelihood of misunderstanding it (they'll have
> > to read the documentation) while paralleling the meaning of the matcher
> > `on` and the behavior of `thisPointerType` (which also allows either the
> > type or the pointer to that type).
> >
> > 2. My particular concern with `onOrPointsToType` is that it sounds like the
> > "or" applies to the `on` but it really means "on (type or points to type)".
> >
> So far, my observations are:
> 1. three engineers quite familiar with the topic can't come up with a name
> that would explain the concept behind this matcher
> 2. anyone reading that name would have to look up the documentation
> 3. the implementation of the matcher is straightforward and even shorter than
> the documentation
>
> Should we give up and let users just type `on(anyOf(hasType(Q),
> hasType(pointsTo(Q))))`?
>
> If we want a bit more brevity here, maybe introduce a `hasTypeOrPointsToType`
> matcher (any bikeshed color will do ;) to shorten the expression above?
Yes to both suggestions (dropping this one and adding `hasTypeOrPointsToType`).
It seems a rather obvious conclusion now that you've said it. :)
Personally, I'd go with `hasOrPointsToType`, but agreed that its just bike
shedding. Aaron?
I'll drop this diff and create a new one for the new matcher.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D56851/new/
https://reviews.llvm.org/D56851
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