[cfe-dev] Include Default C++ paths

[Mohammad Adil]

I've done the following. I've taken the source of
createInvocationFromCommandLine(). Edited it a little and added the
following important line:

TheDriver.CCCIsCXX = true;

   The CompilerInvocation instance now has all the arguments for C++. The
only problem remaining is that the C++ include paths are added AFTER the
input file. Therefore, they are not processed. Why is this happening? How
can I get these paths BEFORE the input file?

On Thu, Oct 18, 2012 at 12:57 PM, Mohammad Adil <madil90 at gmail.com> wrote:

> I have also tried using createInvocationFromCommandLine and
> createInvocationFromArgs. Both of these basically take args to create a
> compiler invocation . What arguments can be given so that clang
> automatically turns into clang++? I mean, isn't there a simple argument
> that can enable the compilation of C++ rather than C just like the variable
> CCCisCXX in the Driver class does?
>
>
> On Thu, Oct 18, 2012 at 12:22 PM, Mohammad Adil <madil90 at gmail.com> wrote:
>
>> I've been looking at the source code of the Driver. What I have
>> understood till now is that the driver is created for the platform we are
>> working on. The driver  can then build a compilation object from a list of
>> arguments. Inside this compilation object, there exists a toolchain
>> specific to the platform (e.g. Linux in my case) which has the job of
>> inserting correct system and C++ include paths. Is that correct? Let us say
>> that I have build such a compilation object. How can I create a
>> CompilerInvocation or CompilerInstance out of this such that it includes
>> the information about all default C and C++ paths? I see no way of using
>> the driver to just create an AST and parse it so the only way is to create
>> a Driver and somehow create a CompilerInstance out of it.
>>
>>
>> On Thu, Oct 18, 2012 at 1:09 AM, Manuel Klimek <klimek at google.com> wrote:
>>
>>> On Wed, Oct 17, 2012 at 6:50 PM, David Blaikie <dblaikie at gmail.com>wrote:
>>>
>>>> (readding cfe-dev)
>>>>
>>>>
>>>>
>>>> On Wed, Oct 17, 2012 at 9:42 AM, Mohammad Adil <madil90 at gmail.com>
>>>> wrote:
>>>> > What I am trying to do is to make a small program which parses the
>>>> AST and
>>>> > does some rewriting to output modified code. How will I use the
>>>> Driver in
>>>> > this case? All I want to do is to parse the AST.
>>>>
>>>> I don't know off-hand what the best way to integrate the Driver's
>>>> lib/header discovery is, just that that's where the logic is.
>>>>
>>>> The focus of Clang development with regard to "tools" like the one you
>>>> described is the Tooling infrastructure (overview of options & a link
>>>> to libTooling-specific information can be found here:
>>>> http://clang.llvm.org/docs/Tooling.html ). I'm not sure if that meets
>>>> the "standalone execution" scenario that you seem to be going for -
>>>> it's ideally meant to integrate with code already building using an
>>>> existing build system that has been modified to generate a database of
>>>> compilation commands. I /think/ it should also work standalone & still
>>>> do all the driver-based discovery, but I could be wrong.
>>>>
>>>
>>> It does not fully do the driver-based discovery, but it'll usually work
>>> with the same flags that you provide to a normal clang call - and you can
>>> always specify options after "--" if you build the tool like in the
>>> tutorials.
>>>
>>> Cheers,
>>> /Manuel
>>>
>>>
>>>>
>>>> > On Wed, Oct 17, 2012 at 9:39 PM, David Blaikie <dblaikie at gmail.com>
>>>> wrote:
>>>> >>
>>>> >> On Wed, Oct 17, 2012 at 9:29 AM, madil90 <madil90 at gmail.com> wrote:
>>>> >> > Hi,
>>>> >> >    I am trying to parse a C++ code but clang doesn't recognize the
>>>> C++
>>>> >> > types. Consider the following code
>>>> >> >
>>>> >> > #include <iostream>
>>>> >> > #include <string>
>>>> >> >
>>>> >> > int main()
>>>> >> > {
>>>> >> >     string str;
>>>> >> > }
>>>> >> >
>>>> >> > clang gives an error at <iostream> and doesn't recognize the string
>>>> >> > type. To
>>>> >> > enable C++, I did "langOptions.CPlusPlus=1" and the code recognizes
>>>> >> > custom
>>>> >> > C++ classes. So how do I include default C++ paths?
>>>> >>
>>>> >> I assume you're using clang as a library, rather than actually going
>>>> >> through the clang driver? The driver's where all (most) of the header
>>>> >> search logic is. You can extract the paths by simply asking clang
>>>> what
>>>> >> command it used to invoke the frontend (I forget offhand, but there
>>>> is
>>>> >> a verbose/print-commands option to clang) & just pass those in. But
>>>> if
>>>> >> you want to make a tool using clang as a library & have the same
>>>> >> header/lib discovery that the clang command line program has, you'd
>>>> >> need to duplicate or reuse the logic in the driver.
>>>> >>
>>>> >> - David
>>>> >
>>>> >
>>>> >
>>>> >
>>>> > --
>>>> > Mohammad Adil
>>>> > LUMS SSE
>>>> >
>>>>
>>>> _______________________________________________
>>>> 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
>
>


-- 
Mohammad Adil
LUMS SSE
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