Re: [Windows]Fix a bug which cause GDB.exe assert when try to run the inferior

[Yao Qi <yao@codesourcery.com>]

On 02/21/2014 03:57 PM, Yao Qi wrote:
> On 02/21/2014 03:37 PM, Eli Zaretskii wrote:
>>> Date: Fri, 21 Feb 2014 15:03:31 +0800
>>> From: Yao Qi <yao@codesourcery.com>
>>> CC: <gdb-patches@sourceware.org>
>>>
>>> 2014-02-21  Yuanhui Zhang  <asmwarrior@gmail.com>
>>>
>>> 	* windows-nat.c (windows_xfer_shared_libraries): Return
>>> 	TARGET_XFER_EOF if LEN is zero.
>>
>> Indeed.  May I also suggest to point to the details of the underlying
>> problem, or include its summary, in the ChangeLog entry?
>>
> 
> I prefer to put the details of the underlying problem in commit log,
> but I am fine to include its summary in the ChangeLog entry.
> 
> How about this?
> 
> In commit log:
> 
> A GDB internal error is found on native mingw32 target.
> 
> (gdb) run
> ../../binutils-gdb/gdb/target.c:1483: internal-error:
> target_xfer_partial: Assertion `*xfered_len > 0' failed.
> A problem internal to GDB has been detected,
> further debugging may prove unreliable.
> Quit this debugging session? (y or n)
> 
> This error was introduced by the following snippet in commit
> 9b409511d07fe375284701af34909fb539029caf
> 
>> @@ -2536,27 +2538,30 @@ windows_xfer_shared_libraries (struct target_ops *ops,
>>      }
>>  
>>    obstack_free (&obstack, NULL);
>> -  return len;
>> +  *xfered_len = (ULONGEST) len;
>> +  return TARGET_XFER_OK;
>>  }
> 
> In the original code, len is returned, which could be 0, but after that
> commit, only TARGET_XFER_OK is returned, which is wrong.  If len is 0,
> TARGET_XFER_EOF should be returned.  (it is 0 in enum
> target_xfer_status declaration).
> 
> gdb:
> 
> 2014-02-21  Yuanhui Zhang  <asmwarrior@gmail.com>
> 
> 	* windows-nat.c (windows_xfer_shared_libraries): Return
> 	TARGET_XFER_EOF if LEN is zero to fix an assert failure when
> 	requested object is TARGET_OBJECT_LIBRARIES.
> 

Please update your patch to replace "len ?" with "len != 0 ?" and commit
log we discussed here.  You can push it in.

Let me know if you don't have a commit access or have trouble on
committing, I can commit this patch for you.

-- 
Yao (齐尧)