use GDB to debug Win32 app with gcc components?

[Jim Marshall]

Should I be able to use GDB to load and execute a VC++ application, and 
debug DLLs that application loads that where built with gcc?


fwiw:
Windows XP Pro SP2
GNU gdb 6.5.50.20060706-cvs (cygwin-special)

more detail:
I have an application that was compiled with MS Visual C++ 6.0, it is a 
"Release" build. This application loads DLLs on demand and executes some 
functions in those DLLs. I have built a DLL using gcc (gcc (GCC) 3.4.4 
(cygming special, gdc 0.12, using dmd 0.125)) with the debug option (as 
well as -mno-cygwin). I would like to use GDB to debug the DLL I developed.

When I run GDB and tell it to start my application ('run' command) it 
starts to load the program but eventually GDB 'stops' as it loading 
various DLL's

Loaded symbols for /cygdrive/c/WINDOWS/system32/ntdll.dll
Loaded symbols for /cygdrive/c/WINDOWS/system32/kernel32.dll
...
Loaded symbols for /cygdrive/c/Program Files/foo/lib/doo.dll

[1]+  Stopped                 gdb cwbemserver.exe

and I get bounced down to the xterm shell, if I type 'fg' at the xterm 
window GDB will come up:

$ fg
gdb myserver.exe
---Type <return> to continue, or q <return> to quit---

Eventually this will appear to hang:

$ fg
gdb myserver.exe
---Type <return> to continue, or q <return> to quit---q
q
Quit
---Type <return> to continue, or q <return> to quit---


pressing ctrl-c has no affect (pressing <return> just adds an empty line 
to the display).

Note that the dll I want to debug has not been loaded at this point. 
Please note the application loads and runs fine from a command prompt or 
an xterm session in cygwin.

any thoughts?



As an aside, if I start the process and then attach GDB to it, I get a 
bit further in that I can set a break point in my DLL but once I hit the 
breakpoint things go down hill:

[Switching to thread 5824.0x1f4]

Breakpoint 1, initializeCMPIProvider (dlhandle=0x962114, pProv=0xb75260,
    pName=0xb805c0) at ../src/cmpiprovider.c:235
235         if (NULL == (cMIname = createCharFromCIMString(pName))) {
(gdb) n
Warning:
Cannot insert breakpoint -144.
Error accessing memory address 0x61092ded: Input/Output error.

I have 'rwx' permission in the directories that the application is 
running in.

Thanks