[cfe-dev] Matching bools

[Daniel Jasper]

+cfe-dev

The const-case was just an example. You have similar problems with
arrays, pointers, references (where to put [], * and &? where to put
spaces?), types with typedefs, ...

I am working on a sensible way to match types (see
http://llvm-reviews.chandlerc.com/D47), which will enable better Type
matching. The AST-matcher language is a good way to describe patterns
in the AST and we don't want a second language based on strings. Thus,
I am  against extending the functionality of asString in any way.

On Mon, Oct 8, 2012 at 2:06 PM, Gábor Horváth <xazax.hun at gmail.com> wrote:
> What about forcing asString to only match unqualified types, and force users
> to use isConstqualified and other matchers for qualifiers together with
> asString? If asString would match both the cannonical types and typedefs,
> and ignored qualifiers, would it cause any problem? It sounds considerably
> user friendly for me.
>
>
> On 8 October 2012 10:31, Daniel Jasper <djasper at google.com> wrote:
>>
>> We actually had a longish discussion whether we wanted to have the
>> asString-matcher at all. The problem is that there is no canonical way
>> to convert a Type to a string. As an easy example, you could write in
>> the code "const int a;" or "int const a;" and asString() would always
>> give you "const int" (or the other, but where can you look that up?).
>> We decided on including it simply wrapping QualType::asString() just
>> because it is very convenient in some places. I don't see an easy way
>> of making this a good general purpose user interface.
>>
>> On Sun, Oct 7, 2012 at 10:38 PM, Gábor Horváth <xazax.hun at gmail.com>
>> wrote:
>> > Hi!
>> >
>> > With "_Bool" it works flawlessly thanks. I wonder if isBoolean is an
>> > user
>> > friendly solution, as one might except to use asString with any type.
>> > However I admint, making asString matcher able to match everything might
>> > add
>> > unnecessary complexity.
>> >
>> > Thanks,
>> > Gábor
>> >
>> >
>> > On 7 October 2012 22:21, Daniel Jasper <djasper at google.com> wrote:
>> >>
>> >> +cfe-dev
>> >>
>> >> Hi Gábor,
>> >>
>> >> I think the AST-internal-name of the type bool is '_Bool'. Can you try
>> >> that with the asString-matcher? However, I think the right solution
>> >> would be to write a matcher like:
>> >>
>> >> AST_MATCHER(QualType, isBoolean) {
>> >>   return Node->isBooleanType();
>> >> }
>> >>
>> >> Cheers,
>> >> Daniel
>> >>
>> >> On Sun, Oct 7, 2012 at 10:06 PM, Gábor Horváth <xazax.hun at gmail.com>
>> >> wrote:
>> >> > Hi!
>> >> >
>> >> > I can't figure out how can I match bool types.
>> >> >
>> >> > First of all, I had a matcher like this:
>> >> >
>> >> >
>> >> > classTemplateSpecializationDecl(hasAnyTemplateArgument(refersToType(asString("bool"))))
>> >> >
>> >> > but asString("bool") did not give me any match, however using any
>> >> > other
>> >> > types would. First of all, I thought, maybe bool is a typedef, and
>> >> > that
>> >> > can
>> >> > cause the problem, so I alstered the asString matcher, to also check
>> >> > the
>> >> > name of the cannonical type.
>> >> >
>> >> > It looks now like this one:
>> >> > AST_MATCHER_P(QualType, asString, std::string, Name) {
>> >> >   return Name == Node.getAsString() || Name ==
>> >> > Node.getCanonicalType().getAsString();
>> >> > }
>> >> >
>> >> > However I still has no success.
>> >> >
>> >> > Thanks for your answer in advance,
>> >> > Gábor
>> >
>> >
>
>