Re: Why does fwrite() behave like this?

From:

Scot T Brennecke <ScotB@Spamhater.MVPs.org>

Newsgroups:

microsoft.public.vc.language

Date:

Sat, 26 Sep 2009 18:43:21 -0500

Message-ID:

<uQThiMwPKHA.1796@TK2MSFTNGP02.phx.gbl>

Vincent Fatica wrote:

On Fri, 25 Sep 2009 01:16:35 -0500, Scot T Brennecke <ScotB@Spamhater.MVPs.org>
wrote:

|"kp" works for me -- gives all args. Do you have matching symbols?

I get symbols from the web. I imagine I have them for kernel32.dll. But I get
the likes of this. Where are the params for MultiByteToWideChar?

Breakpoint 0 hit
eax=00000001 ebx=00000000 ecx=87c0bbd4 edx=785237d2 esi=7c809c88 edi=0012f3d0
eip=7c809c88 esp=0012f37c ebp=0012f3ac iopl=0 nv up ei pl zr na pe nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00000246
kernel32!MultiByteToWideChar:
7c809c88 8bff mov edi,edi
0:000> kp
ChildEBP RetAddr
0012f378 7858fba6 kernel32!MultiByteToWideChar
0012f3ac 7858fced MSVCR90!__crtGetStringTypeA_stat(struct localeinfo_struct *
plocinfo = 0x87c0bbd4, unsigned long dwInfoType = 1, char * lpSrcStr =
0x0012f828 " ???", int cchSrc = 256, unsigned short * lpCharType = 0x0012f428,
int code_page = 1252, int lcid = 0, int bError = 0)+0xa8
[f:\dd\vctools\crt_bld\self_x86\crt\src\a_str.c @ 153]

I may have spoken too soon. Sometimes, the public version of symbols does not have more than the function name to map to an address
range. These are also known as "stripped" symbols. Those who have access to the private symbols will see everything. However,
using kb, you can see the three DWORDs on the stack for the function call. Referring to the docs for MultiByteToWideChar Function
(Windows):
http://msdn.microsoft.com/en-us/library/dd319072(VS.85).aspx
you can see that it takes six parameters, so seeing those three may not be enough. However, you can use the "dds" (or one of that
family of commands) to examine the stack and see other parameters that were pushed prior to the call.