[cfe-dev] libclang crash when parsing MS-style inline assembly

[Alp Toker]

On 08/11/2013 19:52, Reid Kleckner wrote:
> On Fri, Nov 8, 2013 at 1:12 AM, Kim Gräsman <kim.grasman at gmail.com
> <mailto:kim.grasman at gmail.com>> wrote:
>
>     Hi Alp,
>
>     On Fri, Nov 8, 2013 at 8:01 AM, Alp Toker <alp at nuanti.com
>     <mailto:alp at nuanti.com>> wrote:
>     >
>     > Now that we've dealt with the underlying crash, we can start to
>     look at
>     > how to handle this cleanly.
>     >
>     > I'd like to understand your requirements first..
>     >
>     > For your use cases, would it be acceptable to skip over the MS
>     inline
>     > assembly without parsing it, ie. having a special mode that
>     turns this
>     > into a soft error in parse-only tools?
>
>     For me, I think so.
>
>     We ran into this in IWYU [1], and I don't think inline assembly would
>     introduce a "use" of any significance...
>
>
> Muahahaha:
>
> // foo.h
> struct Foo {
>   static const int x = 20;
> };
> // foo.cc
> int main() {
>   int r;
>   __asm {
>     mov ecx, Foo::x
>     mov r, ecx
>   };
>   return r;
> }
>
> Seems like a use that is relevant to IWYU.  :)

Exactly what I was thinking.

Looks like we'll end up having to do something like this for both
Tooling and libclang :-/

  LLVMInitializeX86TargetInfo();
  LLVMInitializeX86TargetMC();
  LLVMInitializeX86AsmParser();

On the plus side, it only pulls in an extra 1M on the binary size.

Alp.

>  
>
>     I'm not sure what you mean by "soft error", but I think I'd just
>     ignore it completely rather than spewing diagnostics for things we
>     can't affect and don't really care about.
>
>     We don't use libclang, the problem is a little different there, as
>     they can't initialize the respective targets. Our current workaround
>     solves the problem for us.
>
>     Thanks!
>
>     - Kim
>
>     [1] https://code.google.com/p/include-what-you-use/
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>

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