[cfe-dev] Retrieve variable name

[Richard Smith]

On Thu, Jan 8, 2015 at 3:09 PM, Alberto Barbaro <barbaro.alberto at gmail.com>
wrote:

> Hi,
> I hope this can help someone. I solved in this way:
>
> Expr *e = (dyn_cast<ImplicitCastExpr>(d->getInit()))->getSubExpr(); //
> return an object that points to b
>
> dyn_cast<DeclRefExpr>(e)->getNameInfo().getAsString(); //this return b
>

If you're going to assume that 'e' is a DeclRefExpr (and likewise for the
ImplicitCastExpr case), use cast<> rather than dyn_cast. Otherwise, you
should cope with dyn_cast returning nullptr.


> Thanks for your help,
> Alberto
>
> 2015-01-08 11:19 GMT+00:00 Alberto Barbaro <barbaro.alberto at gmail.com>:
>
>> Yes yes, I'll do it.
>>
>> Thanks,
>> Alberto
>> On 8 Jan 2015 11:18, "Manuel Klimek" <klimek at google.com> wrote:
>>
>>> Well, you'll need to dyn_cast and look through the implicitcast node,
>>> but apart from that, sounds about right.
>>>
>>> On Thu Jan 08 2015 at 10:30:02 AM Alberto Barbaro <
>>> barbaro.alberto at gmail.com> wrote:
>>>
>>>> Hi Manuel,
>>>> thanks for your help.
>>>>
>>>> Yes i meant "int main()". Based on what you said I think I should do
>>>> something like: decl->getInit()->getNameInfo()->getName();
>>>>
>>>> Thanks,
>>>> Alberto
>>>>
>>>> 2015-01-08 8:54 GMT+00:00 Manuel Klimek <klimek at google.com>:
>>>>
>>>>> getInit should be/contain a declrefexpr
>>>>>
>>>>> On Wed, Jan 7, 2015, 21:41 Alberto Barbaro <barbaro.alberto at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Hi all,
>>>>>> please consider this code:
>>>>>>
>>>>>> int main {
>>>>>>
>>>>>
>>>>> I assume you mean "main()"
>>>>>
>>>>>
>>>>>>    int a = 7;
>>>>>>    int b = a;
>>>>>> }
>>>>>>
>>>>>> I have a Decl object called decl that represents int b = a; If i do
>>>>>> decl->getInit() i can have an Expr pointer that represents a I think. From
>>>>>> there how can i retrieve the variable name 'a'? Maybe using
>>>>>> getNameAsString()? I tried but it didn't work.
>>>>>>
>>>>>
>>>>> As  -ast-dump shows, getInit is a ImplicitCastExpr which has a
>>>>> DeclRefExpr which points to 'a'.
>>>>>
>>>>> $ clang_check -ast-dump /tmp/t.cc --
>>>>> TranslationUnitDecl 0x21c05e0 <<invalid sloc>> <invalid sloc>
>>>>> |-TypedefDecl 0x21c0b20 <<invalid sloc>> <invalid sloc> implicit
>>>>> __int128_t '__int128'
>>>>> |-TypedefDecl 0x21c0b80 <<invalid sloc>> <invalid sloc> implicit
>>>>> __uint128_t 'unsigned __int128'
>>>>> |-TypedefDecl 0x21c0f40 <<invalid sloc>> <invalid sloc> implicit
>>>>> __builtin_va_list '__va_list_tag [1]'
>>>>> `-FunctionDecl 0x21c0fe0 </tmp/t.cc:1:1, line:4:1> line:1:5 main 'int
>>>>> (void)'
>>>>>   `-CompoundStmt 0x21c1240 <col:12, line:4:1>
>>>>>     |-DeclStmt 0x21c1168 <line:2:3, col:12>
>>>>>     | `-VarDecl 0x21c10f0 <col:3, col:11> col:7 used a 'int' cinit
>>>>>     |   `-IntegerLiteral 0x21c1148 <col:11> 'int' 7
>>>>>     `-DeclStmt 0x21c1228 <line:3:3, col:12>
>>>>>       `-VarDecl 0x21c1190 <col:3, col:11> col:7 b 'int' cinit
>>>>>         `-ImplicitCastExpr 0x21c1210 <col:11> 'int' <LValueToRValue>
>>>>>           `-DeclRefExpr 0x21c11e8 <col:11> 'int' lvalue Var 0x21c10f0
>>>>> 'a' 'int'
>>>>>
>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>> Alberto
>>>>>> _______________________________________________
>>>>>> cfe-dev mailing list
>>>>>> cfe-dev at cs.uiuc.edu
>>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>>>>>
>>>>>
>>>>
>
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20150108/a023f6a9/attachment.html>