[cfe-dev] Relationship between ObjCPropertyRefExpr and ObjCIvarDecl

[Hendrik vP]

I haven't had a very deep look into the Sema-code, as my knowledge of the
internals
of clang at this level isn't that good that i could benefit from it.
Instead, i tried to get the ObjCIvarDecl with the methods I know and I'm
used too - and
finally i got it.
I get to the ObjCInterfaceDecl through the ValueDecl that lies in the deeps
of the base of
the ObjCPropertyRefExpr. Through this, I can get to the
ObjCImplementationDecl, to
the ObjCPropertyImplDecl and to the ObjCIvarDecl. By comparing the
getter-name within
the ObjCPropertyRefExpr, i finally can find the right ObjCPropertyImplDecl
and the
ObjCIvarDecl. The method itseld can be found at
http://pastebin.com/VEVACTvP
I still have no clue if clang misses something in Sema to set the
ObjCIvar-reference on
the ObjCPropertyDecl, or if I'm misinterpreting some methods or maybe if it
is totally
wrong what I'm doing - but for now, it seems to work and I'm going to grant
now my
braincells some cooldown ;)

2011/3/16 Hendrik vP <variadic.template at googlemail.com>

> The items-property gets synthesized within the implementation. But i just
> realized
> that i missed two details within my example, those are
> 1. Foo implements a protocol with a method, call it bar
> 2. the access to the items happen inside the implementation of bar
> Is it possible that clang doesn't resolve the ObjCIvar as it isn't a method
> that got
> declared within the interface or something like that?
>
> I'll take a look into Sema::ActOnPropertyImplDecl - thank you so far.
>
> 2011/3/16 Fariborz Jahanian <fjahanian at apple.com>
>
>> It only sets it for synthesized ivars. Look at Sema::ActOnPropertyImplDecl
>> for details. You can follow
>> the same logic for looking up the ivar;  starting at if (Synthesize) {...}
>>
>> - Fariborz
>>
>> On Mar 16, 2011, at 8:49 AM, Hendrik vP wrote:
>>
>> > I'm experimenting with clang to do some analyzes and inspections on
>> > Objective-C-code, or, to be more precise, iPhone-Code.
>> > Currently, I'm trying to 'guess' the inner-types of enumeratable types,
>> especially for
>> > NSArrays. For this, I set up a RecursiveASTVisitor and collect all of
>> the variables
>> > that I am interested in (ObjCIVar, VarDecl, ParmVarDecl). Also, I'm
>> looking into
>> > statements and declarations where those variables get used. I already
>> got it to
>> > guess some inner-types by inspecting ObjCForCollection-statments, which
>> is
>> > fine.
>> > Now, I'm doing some specializations for NSMutableArray inside my visitor
>> to get
>> > some hints from statements like
>> > [<NSMutableArray> addObject:<variable X>]
>> > so i can build a relationship between the type of variable X and the
>> inner-type of
>> > the array. This already works for local declared arrays, but not for
>> ObjCIvars.
>> > For the moment, I'm stuck with an expression that looks like
>> > [self.items addObject:item]
>> > where items is declared as
>> >
>> >
>> > @interface Foo : NSObject {
>> > @private
>> >   NSMutableArray *items;
>> > }
>> > @property(retain) NSMutableArray *items;
>> > @end
>> >
>> > @implementation Foo
>> > @synthesize items;
>> > @end
>> >
>> >
>> > So, I'm diving into the ObjCMessageExpression and try to get the
>> ObjCIvarDecl.
>> > For this, I'm catching the instance-receiver, which is a
>> ImplicitCastExpr, get it's
>> > subExpr and cast it to the ObjCPropertyRefExpr that it is. On this, I'm
>> calling
>> > getExplicitProperty() and receiving the ObjCPropertyDecl.
>> >
>> > And here's the point that confuses me: when I try to get the
>> ObjCIvarDecl by
>> > calling getPropertyIvarDecl on the ObjCPropertyDecl, I'm receiving a
>> nullpointer.
>> >
>> > The header of Foo is included and also my compilerinstance reports no
>> errors,
>> > so i think the configuration of the project itself should be correct. Am
>> I
>> > misunderstanding the concept/functionality of the methods I'm using - or
>> is it
>> > maybe a bug inside clang, that it doesn't set the ObjCIvarDecl properly
>> for
>> > every ObjCProperetyDecl?
>> > svn log says that I am using r127573.
>> >
>> > Thanks,
>> > Hendrik
>> > _______________________________________________
>> > cfe-dev mailing list
>> > cfe-dev at cs.uiuc.edu
>> > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>
>>
>
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