From: K. F. <kfr...@gm...> - 2012-09-11 20:37:40
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Hello Kai! Thank you for making the test. On Tue, Sep 11, 2012 at 10:16 AM, <kai...@no...> wrote: > >> -----Original Message----- >> From: ext K. Frank [mailto:kfr...@gm...] >> >> Hai Kai! >> >> On Tue, Sep 11, 2012 at 4:10 AM, <kai...@no...> wrote: >> >> -----Original Message----- >> >> [...] >> >> Does anyone else see the slowness when first executing "run" >> >> when debugging a Qt gui application with gdb? >> >> >> >> Can anyone proactively confirm that the slowness does not occur with >> >> some specific mingw-w64 build (preferably 4.7.0 or later) when using >> >> gdb to debug a Qt gui application built with that mingw-w64 build? >> >> If so, what mingw-w64 build would that be? >> > ... >> It takes 12 seconds from >> startup to hitting a breakpoint in main.cpp, compared to 4 seconds with the >> gdb from niXman. >> ... >> Thank you for the feedback. >> >> It sounds like you are seeing some slowness with Ruben's build, but nothing >> on the scale I'm seeing. (As I mentioned, it takes minutes for my application to >> launch after executing the gdb "run" command.) >> >> Would you be able to try your test with a simple Qt gui application? > > I did now. Startup from typing 'run' in a stock gdb session to the display of the main window is about 14 seconds. So no, for me it's not minutes. Thanks very much for taking the trouble to look. Well, you're not seeing what I'm seeing. > >> Also, how is your application built? In my case, I built Qt with the same mingw- >> w64 compiler, and built it "out of the box," in that I used all of the Qt default >> build configuration settings. My Qt application is also an "out of the box" >> build, in that I don't use any non-default setting (other than adding "CONFIG >> += console" so that diagnostic messages will be visible.) > > I'm using the setup described under: > > http://qt-project.org/wiki/MinGW-64-bit > > The MinGW package is native 64 bit : x86_64-mingw-w64-gcc-4.7.1-release-c,c++,fortran-sjlj-rev3.7z . > 'configure -debug -prefix "%CD%\qtbase" -opensource -confirm-license -nomake examples -nomake tests' That looks pretty plain-vanilla, so probably not the explanation. > The application was a barebone application with an empty QMainWindow. > > Regards > > Kai > >> > So yes, something's fishy here. Both are using a quite similar gdb version: >> 7.5.50.20120816-cvs (rubenv's) vs 7.5 (mingw-builds). The only other >> difference from the log is that rubenv's gdb also prints some '=cmd-param- >> changed,param="' messages, while mingw-builds does not. >> >> What log is this? I haven't notices gdb emitting any unexpected messages, but >> I'd be glad to look if this might be a hint about something. > > This is from the debugger log output of Qt Creator (Window->Views->Debugger Log). Logging the exact times a command took can be enabled in the context menu. Okay. I don't use Qt Creator, so I guess I don't have this log. > Regards > > Kai The (minutes-long) slowness I'm seeing is still a bit of a mystery then. I will work under the assumption that it's an oddity of the particular build of mingw-w64 that I am using, and just ignore it for the time being. I will hope it goes away the next time I get around to upgrading the compiler I use. Thanks for everyone's help (and sorry for wandering off topic). K. Frank |