[cfe-dev] MS style ASM failure and crash

[Reid Kleckner]

It is, but you probably want to look for any RecordDecl to see if it's
possible to do a field access.  You can use Decl->getAs<RecordDecl>() to
look through typedefs automatically.


On Thu, Feb 27, 2014 at 11:12 AM, JB Feldman <jb.feldman at kyrus-tech.com>wrote:

> I'm trying to track this down, am I correct that in the example I pasted
> above: "KPCR" (in the bug report, "s") should be a TypedefNameDecl?
>
>
> On Thu, Feb 27, 2014 at 11:38 AM, JB Feldman <jb.feldman at kyrus-tech.com>wrote:
>
>> Bug has been filed: http://llvm.org/bugs/show_bug.cgi?id=18994
>>
>>
>> On Thu, Feb 27, 2014 at 10:52 AM, Reid Kleckner <rnk at google.com> wrote:
>>
>>> This also happens (just once) in the Chromium build:
>>>
>>> http://build.chromium.org/p/chromium.fyi/builders/Chromium%20Win%20Clang/builds/645/steps/compile/logs/stdio
>>>
>>> Parsing this involves Clang and
>>> llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp.  It's really tricky because
>>> C++ expressions can occur in lots of places, making it harder to parse the
>>> assembly.
>>>
>>> Feel free to file a bug on this.
>>>
>>>
>>> On Thu, Feb 27, 2014 at 7:22 AM, JB Feldman <jb.feldman at kyrus-tech.com>wrote:
>>>
>>>> Hi guys,
>>>>
>>>> I will file a bug report in a little bit (once I get a minimal test
>>>> case) but I wanted to ask if anyone understands the problem I'm seeing.
>>>>
>>>> Trying to include ntddk.h and compiling with clang-cl, I get the
>>>> following message:
>>>>
>>>> In file included from kbfiltr.c:19:
>>>> In file included from ./kbfiltr.h:28:
>>>> C:\WINDDK\3790.1830\inc\ddk\wxp\ntddk.h(7149,29) :  error: unexpected
>>>> type name
>>>>       'KPCR': expected expression
>>>>     __asm {  movzx eax, _PCR KPCR.Number  }
>>>>                              ^
>>>> Assertion failed: End.getPointer() <= EndPtr && "frontend claimed part
>>>> of a token?", file
>>>> ..\..\..\..\..\lib\Target\X86\AsmParser\X86AsmParser.cpp, line 1481
>>>> clang-cl.exe: error: clang frontend command failed with exit code 3
>>>> (use -v to s
>>>> ee invocation)
>>>>
>>>> The assertion failure obviously results in a crash.
>>>>
>>>> So my initial guess was some kind of Lexer issue, maybe because of no
>>>> semicolon, or... who knows. But then, I rewrote that code to read:
>>>>
>>>> int x = FIELD_OFFSET(KPCR, Number);
>>>> __asm { movzx eax, fs:[x] }
>>>>
>>>> Which compiles to the same code, and that actually did work with
>>>> clang-cl. Can anyone tell me why one works and the other doesn't? (My
>>>> guess: MS not following standard Intel notation spec)
>>>>
>>>> Thanks,
>>>> JB
>>>>
>>>> _______________________________________________
>>>> cfe-dev mailing list
>>>> cfe-dev at cs.uiuc.edu
>>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>>>
>>>>
>>>
>>
>
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