[cfe-commits] [PATCH]: Matchers for ignoring paren/implicit casts

[Manuel Klimek]

On Thu, Aug 2, 2012 at 7:48 PM, Sam Panzer <panzer at google.com> wrote:
> Here you go.

Sorry for not getting to this earlier - apparently nobody has
submitted this yet :)
I'm happy to submit it, but patch complains about the patch - is there
a reason there are no newlines after the @@ ... @@ parts?

Cheers,
/Manuel

>
>
> On Thu, Aug 2, 2012 at 7:04 AM, Manuel Klimek <klimek at google.com> wrote:
>>
>>
>> A couple more things:
>> - please completely take out the type() matcher - I've looked into it,
>> and we need to come up with a good design here first; until then I
>> don't think it makes sense to have a hack in
>> - please rename castExpression -> castExpr to be consistent with the node
>> name
>>
>> Apart from that lgtm
>>
>> Cheers,
>> /Manuel
>>
>> On Mon, Jul 30, 2012 at 7:49 PM, Sam Panzer <panzer at google.com> wrote:
>> >
>> > A new version, with shorter (Implicit --> Imp) matcher names!
>> >
>> > On Mon, Jul 30, 2012 at 5:32 AM, Manuel Klimek <klimek at google.com>
>> > wrote:
>> >>
>> >>
>> >> On Thu, Jul 26, 2012 at 11:15 PM, Sam Panzer <panzer at google.com> wrote:
>> >> >
>> >> > Here's the next version!
>> >> >
>> >> > On Thu, Jul 26, 2012 at 1:53 AM, Manuel Klimek <klimek at google.com>
>> >> > wrote:
>> >> >>
>> >> >>
>> >> >> +/// \brief Matches expressions that match InnerMatcher after
>> >> >> parentheses
>> >> >> and
>> >> >> +/// casts are stripped off.
>> >> >> +///
>> >> >> +/// Implicit and non-C Style casts are not discarded.
>> >> >>
>> >> >> This contradicts the example...
>> >> >
>> >> >
>> >> > s/not/also/
>> >> > Though I'm not sure if this makes it any clearer than not having a
>> >> > comment.
>> >> >
>> >> >>
>> >> >>
>> >> >> +/// \brief Matches any cast nodes of Clang's AST.
>> >> >> +///
>> >> >> +/// Example: castExpression() matches each of the following:
>> >> >> +///   (int) 3;
>> >> >> +///   const_cast<Expr *>(SubExpr);
>> >> >> +///   (i);
>> >> >> +///   char c = 0;
>> >> >> +const internal::VariadicDynCastAllOfMatcher<
>> >> >> +  Expr,
>> >> >> +  CastExpr> castExpression;
>> >> >
>> >> >
>> >> > Actually, this comment wasn't correct either, since parentheses
>> >> > aren't
>> >> > CastExpr's. Fixed!
>> >> >
>> >> >>
>> >> >>
>> >> >> I'd vote for calling all new matchers we write exactly like the AST
>> >> >> nodes (castExpr in this case).
>> >> >> I lost the fight, and if we ever want to get to the place where it
>> >> >> all
>> >> >> just works, we have to start not introducing new violations of that
>> >> >> rule.
>> >> >> Same for Implicit -> Imp (it hurts me, but, oh well, I'll live ;)
>> >> >
>> >> >
>> >> > I would agree on the AST-style naming convention. I can see three
>> >> > naming
>> >> > styles for CastExpr among existing matchers: cast (already taken!),
>> >> > castExpression (what I used), and castExpr.  Which cast matchers are
>> >> > you
>> >> > suggesting should be renamed, and to what? I'll be happy to change
>> >> > them,
>> >> > but
>> >> > I'm not sure what you're asking.
>> >>
>> >> ignoringImplicitCasts -> ignoringImpCasts
>> >> ignoringParenImplicitCasts -> ingoringParenImpCasts
>> >
>> >
>> > Done.
>> >
>> >>
>> >>
>> >> >> +  EXPECT_TRUE(matches("char *p = reinterpret_cast<char *>(&p);",
>> >> >> +                      expression(castExpression())));
>> >> >>
>> >> >> Btw, if we defined the castExpr as VariadicDynCastAllOfMatcher<Stmt,
>> >> >> CastExpr> just putting them in top-level would work, too. Since a
>> >> >> Matcher<Stmt> is-a Matcher<Expr> this would also not limit the use
>> >> >> of
>> >> >> castExpr.
>> >> >>
>> >> >
>> >> > I was following the other cast examples such as implicitCast. Would
>> >> > it
>> >> > be
>> >> > better to change this?
>> >>
>> >> Yes, and I think we should change the others, but not in this CL; just
>> >> use
>> >> const internal::VariadicDynCastAllOfMatcher<Stmt, CastExpr>
>> >> castExpression;
>> >>
>> >> >
>> >> >>
>> >> >> +                          pointsTo(TypeMatcher(anything())))))));
>> >> >>
>> >> >> This is unfortunate. We should add a type() matcher.
>> >> >
>> >> >
>> >> > I've used this workaround in my client code - and I just discovered
>> >> > that
>> >> > the
>> >> > test Matcher.HandlesNullQualTypes does too (with a fixme echoing your
>> >> > complaint):
>> >> >   const TypeMatcher AnyType = anything();
>> >> >
>> >> > I briefly tried adding a type() matcher, but it seems like matchers
>> >> > treat
>> >> > types differently from statements and declarations. All existing
>> >> > matchers on
>> >> > types just take a single argument, which is usually hasDeclaration()
>> >> > in
>> >> > some
>> >> > form (often indirectly), so it's not as easy as adding another
>> >> > AST_MATCHER
>> >> > definition. I'll leave this up to someone who really knows how the
>> >> > new
>> >> > matcher should fit in :)
>> >>
>> >> A type matcher would be added like this:
>> >> const internal::VariadicDynCastAllOfMatcher<QualType, QualtType> type;
>> >
>> >
>> > I tried that already. It fails because QualType does not define the
>> > member
>> > functions needed for dyn_cast to work, i.e. classOf(). I'm not brave
>> > enough
>> > to try modifying QualType directly just for a type matcher, nor am I
>> > sure
>> > that it's the right fix.
>> >
>> >>
>> >>
>> >> >> +TEST(CastExpression, MatchesSimpleCases) {
>> >> >>
>> >> >> I'm not really happy with those names, but I'm aware it's really
>> >> >> hard
>> >> >> to come up with good test names in those cases.
>> >> >
>> >> >
>> >> > I broke the test into MatchesImplicitCasts and MatchesExplicitCasts,
>> >> > both of
>> >> > which are much better names.
>> >> >
>> >> >
>> >> >
>> >
>> >
>
>