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Hello, Nicolas Roche asked me to submit one of the changes he made for us to improve the situation when the user hits Ctrl-c while the inferior runs in a different console. Right now, interrupting only works when when debugger and inferior run in the same console, or when the user hits Ctrl-c in the console where the program runs. The meat of his patch is to use the DebugBreakProcess routine, which stops a given process. One of the issues we had was that this routine is only available starting with Windows XP, meaning that it doesn't work for Windows 2000. What we elected to do was to get a handle on the kernel32.dll, and from there create a pointer to this function if it exists. That way, if the function exists, then we interrupt, otherwise we do nothing, which is was we do now. I should also mention that this patch is not perfect, as the DebugBreakProcess routine causes a SIGTRAP event to be triggered, whereas we would have of course prefered a SIGINT event. Not perfect, but still better than before. Translating the SIGTRAP into a SIGINT is not necessarily trivial, because of possible races between the moment GDB receives the SIGINT and the moment the DebugBreakProcess stops the inferior. I should also mention that Nicolas first came up with a solution that doesn't rely on DebugBreakProcess and works on all versions of Windows that I know. I can't remember all the details, but it is based on creating a thread in the inferior and have that thread send the SIGINT. A consequence of the approach is that we also get the proper signal kind. But it uses a bit of assembly code, which of course probably doesn't work on x86_64, etc, so we both felt that using DebugBreakProcess, despite the drawback mentioned above, is a better approach. We should be able to dig out the code, if anyone is interested. 2008-10-02 Nicolas Roche <roche@adacore.com> * win32-nat.c (check_for_DebugBreakProcess): New function. (ctrl_c_handler): New function. (win32_wait): Register ctrl_c_handler as Ctrl-C handler if the inferior is run in a separate console. (_initialize_win32_nat): Check for DebugBreakProcess in kernel32.dll. This was tested pretty extensively through local usage. Nico tested both cygwin and mingw32. The one thing I would appreciate help on is testing it against the testsuite. We don't anticipate any regression, and our own testsuite (based on a different, simpler technology) showed no regression. Would that be OK to commit? Thanks, -- Joel
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