[cfe-dev] Semantic Analysis in Clang

[Manuel Klimek]

On Fri, Jan 25, 2013 at 2:57 PM, Mohammad Adil <madil90 at gmail.com> wrote:

> I need to insert some code in the file being parser. I need to make sure
> that the resulting file compiles fine. The code that I am inserting will
> mostly be " ostream << type_x ;". Now before I do that, I need to ensure
> that "type_x" has a stream operator defined. Is that possible any other
> way? I am very grateful for your help.
>

What we do in the c++11 transition tools in clang-extra is:
- parse
- detect place to insert
- insert
- reparse, look for errors

Whether that's viable depends on how big the chance is that you're making
an error, and what fallbacks you have.

Cheers,
/Manuel



>
> Regards,
> Adil
>
>
> On Fri, Jan 25, 2013 at 6:34 PM, Manuel Klimek <klimek at google.com> wrote:
>
>> On Fri, Jan 25, 2013 at 1:13 PM, Mohammad Adil <madil90 at gmail.com> wrote:
>>
>>> Thanks for the reply. Well, here's the detailed problem. Once all the
>>> syntax checking has been done, the next step before generating IR is to do
>>> semantic analysis and type checking. Let us say that I encounter a code
>>> like this:
>>>
>>> string b;
>>> vector<T> a;
>>> cout<<b;
>>> cout<<a;
>>>
>>>       How does clang figure out that the 3rd statement is valid because
>>> an operator for string exists, while the 4rth statement is not valid. More
>>> specifically, I want to know how clang searches through all the operators
>>> (or functions). I have to use this functionality. Does the clang api allow
>>> me to do this easily or will I have to replicate this functionality?
>>>
>>
>> As far as I know the clang API does not allow you to do that easily - you
>> need the full semantic analysis state at that point during parsing, and as
>> far as I'm aware this only exists implicitly in the Sema* classes. Overload
>> resolution is one of those really complex and messy parts of C++ :)
>>
>> If you let us know what actual problem you're trying to solve, there
>> might be solutions to that which are simpler than using overload resolution
>> :)
>>
>> Cheers,
>> /Manuel
>>
>>
>>> Regards,
>>> Adil
>>>
>>>
>>>
>>>
>>>
>>> On Fri, Jan 25, 2013 at 4:35 PM, Manuel Klimek <klimek at google.com>wrote:
>>>
>>>> On Thu, Jan 24, 2013 at 12:49 PM, madil90 <madil90 at gmail.com> wrote:
>>>>
>>>>> Hi,
>>>>>    I am looking to perform some semantic analysis in clang. More
>>>>> specifically, I want to know whether a function exists for a certain
>>>>> type.
>>>>> The function is global. e.g.
>>>>>
>>>>> String toString(A a);
>>>>>
>>>>>     I want to differentiate that this function exists for type A and
>>>>> not for
>>>>> type B. I have built an AST and am parsing it. How can I achieve this?
>>>>> (Whenever I encounter a type)
>>>>>
>>>>
>>>> I'd loop over all declarations of toString and see which type they
>>>> take... Perhaps I'm misunderstanding your problem though :)
>>>>
>>>> Cheers,
>>>> /Manuel
>>>>
>>>>
>>>>> Regards,
>>>>> Adil
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> View this message in context:
>>>>> http://clang-developers.42468.n3.nabble.com/Semantic-Analysis-in-Clang-tp4030012.html
>>>>> Sent from the Clang Developers mailing list archive at Nabble.com.
>>>>> _______________________________________________
>>>>> cfe-dev mailing list
>>>>> cfe-dev at cs.uiuc.edu
>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Mohammad Adil
>>> LUMS SSE
>>>
>>
>>
>
>
> --
> Mohammad Adil
> LUMS SSE
>
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