> On Nov. 23, 2014, 12:20 a.m., Thomas Lübking wrote: > > kdecore/io/kdebug.cpp, line 717 > > <https://git.reviewboard.kde.org/r/121213/diff/1/?file=329504#file329504line717> > > > > Why do you need to sharpen the match? > > René J.V. Bertin wrote: > Because otherwise the symbol to be demangled is left with a trailing > space, which causes the demangle to fail. Wanna know how I know? > > Thomas Lübking wrote: > Don't know about the GCC behavior on trailing spaces, but one should > probably have some "while (in.at(mangledNameEnd) == ' ') --mangledNameEnd;" > loop? > > René J.V. Bertin wrote: > One could, but why? The start is found with a string, I don't see why the > end wouldn't be, given that that loop of yours will always loop just once ... > > Thomas Lübking wrote: > ... or not at all or thrice - depending on how the mangler feels today. > > What I mean is that if untrimmed strings are a problem for demangling, > one should seek to get rid of all the whitespace generically - i don't care > about whether seeking for a string or char, this context is hardly > performance critical. > > René J.V. Bertin wrote: > this particular bit of whitespace has nothing to do with the mangler or > how it feels today. It's formatting done by the backtrace function, which > clearly always puts a space-padded `+` rather than one without padding as > under Linux. > Frankly, in general I'd agree with you, but here I don't see any reason > to make the code more complex than it is. > > Thomas Lübking wrote: > backtrace() is provided by glibc resp. the apple (darwin) libc (i hope). > -> What provides /usr/include/execinfo.h on OSX? > That's what is needed to be detected (I assume this would affect *all* > BSD variants?) > > > I don't see any reason to make the code more complex than it is. > > If we're dealing w/ unspecified output and need to sanitize it, we may > have to do this generically if we must consider random toolchains aside > gcc+glibc. > I know that you only care about OSX, but actually OSX is just a good > testcase to see whether the code is "correct" or just happens to work. > > - Do you compile with gcc or clang? > - Did you check whether the glibc backtrace() output is actually stripped? > - What if we compile glibc w/ llvm and glibc backtrace() fires padded " + > " which llvm __cxa_demangle() cannot handle? (ok, rethorical question ;-)
> backtrace() is provided by glibc resp. the apple (darwin) libc (i hope). Not that we have something called libc on OS X, but I think that just underlines my point. The C Library is more part of the system than it is of the C "package", so the only check on compiler that would make sense IMHO is on the system compiler, as far as that's possible (like the Apple-provided __APPLE_CC__). > What provides /usr/include/execinfo.h on OSX? If you're talking about packages: either the standard install, or Xcode and/or "Command Line Tools". One shouldn't take OS X as a guideline for any BSD variant, it might even have diverged too much to use BSD as a guideline for what ought to work on OS X. I agree about the sanitising/generalising, which is why I pulled the suppression of trailing whitespace out of the end token search (and you'll notice I don't just suppress spaces). I just don't think it'd make any sense to have a os/toolchain-specific constant and then the actual search one-liner. Just put that search statement in the conditional block and be done with it. This patch has currently been tested only on 10.9(.4), which means I can basically only test with clang. I can affirm though that the existing code doesn't demangle on 10.6 either, whether I use clang or gcc. > Did you check whether the glibc backtrace() output is actually stripped? I don't understand the question? This is what unparsed output from backtrace_symbols looks like (even adding the counter: isn't required): ``` 0: "0 libkdecore.5.dylib 0x0000000106656f71 _Z14kRealBacktracei + 81" 1: "1 kwindowtest 0x0000000105e322e1 _ZN10TestWindow8slotOpenEv + 2753" 2: "2 kwindowtest 0x0000000105e33d68 _ZN10TestWindow18qt_static_metacallEP7QObjectN11QMetaObject4CallEiPPv + 184" 3: "3 QtCore 0x0000000106c8d3fd _ZN11QMetaObject8activateEP7QObjectPKS_iPPv + 1693" 4: "4 QtGui 0x0000000106faf419 _ZN7QAction8activateENS_11ActionEventE + 233" 5: "5 QtGui 0x00000001073141e4 _ZN22QAbstractButtonPrivate5clickEv + 84" 6: "6 QtGui 0x0000000107314fc8 _ZN15QAbstractButton17mouseReleaseEventEP11QMouseEvent + 88" 7: "7 QtGui 0x00000001073db67f _ZN11QToolButton17mouseReleaseEventEP11QMouseEvent + 15" 8: "8 QtGui 0x00000001070069bd _ZN7QWidget5eventEP6QEvent + 717" 9: "9 QtGui 0x0000000107314ed4 _ZN15QAbstractButton5eventEP6QEvent + 180" 10: "10 QtGui 0x00000001073dbb2a _ZN11QToolButton5eventEP6QEvent + 170" 11: "11 QtGui 0x0000000106fb840c _ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent + 252" 12: "12 QtGui 0x0000000106fba357 _ZN12QApplication6notifyEP7QObjectP6QEvent + 2919" 13: "13 QtCore 0x0000000106c75516 _ZN16QCoreApplication14notifyInternalEP7QObjectP6QEvent + 118" 14: "14 QtGui 0x0000000106fb8df6 _ZN19QApplicationPrivate14sendMouseEventEP7QWidgetP11QMouseEventS1_S1_PS1_R8QPointerIS0_Eb + 470" 15: "15 QtGui 0x0000000106f67a2a _Z23qt_mac_handleMouseEventP7NSEventN6QEvent4TypeEN2Qt11MouseButtonEP7QWidgetb + 922" 16: "16 AppKit 0x00007fff9491f145 -[NSWindow sendEvent:] + 781" 17: "17 QtGui 0x0000000106f5f2f1 -[QCocoaWindow sendEvent:] + 113" 18: "18 AppKit 0x00007fff948c05d4 -[NSApplication sendEvent:] + 2021" 19: "19 QtGui 0x0000000106f640fe -[QNSApplication sendEvent:] + 78" 20: "20 AppKit 0x00007fff947109f9 -[NSApplication run] + 646" 21: "21 QtGui 0x0000000106f6cba0 _ZN19QEventDispatcherMac13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE + 528" 22: "22 QtCore 0x0000000106c728ad _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE + 477" 23: "23 QtCore 0x0000000106c75ac7 _ZN16QCoreApplication4execEv + 199" 24: "24 kwindowtest 0x0000000105e33bdc main + 316" 25: "25 libdyld.dylib 0x00007fff93bb75fd start + 1" 26: "26 ??? 0x0000000000000002 0x0 + 2" ``` which is converted to: ``` 0: 0 libkdecore.5.dylib 0x0000000106656f71 kRealBacktrace(int) + 81 1: 1 kwindowtest 0x0000000105e322e1 TestWindow::slotOpen() + 2753 2: 2 kwindowtest 0x0000000105e33d68 TestWindow::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) + 184 3: 3 QtCore 0x0000000106c8d3fd QMetaObject::activate(QObject*, QMetaObject const*, int, void**) + 1693 4: 4 QtGui 0x0000000106faf419 QAction::activate(QAction::ActionEvent) + 233 5: 5 QtGui 0x00000001073141e4 QAbstractButtonPrivate::click() + 84 6: 6 QtGui 0x0000000107314fc8 QAbstractButton::mouseReleaseEvent(QMouseEvent*) + 88 7: 7 QtGui 0x00000001073db67f QToolButton::mouseReleaseEvent(QMouseEvent*) + 15 8: 8 QtGui 0x00000001070069bd QWidget::event(QEvent*) + 717 9: 9 QtGui 0x0000000107314ed4 QAbstractButton::event(QEvent*) + 180 10: 10 QtGui 0x00000001073dbb2a QToolButton::event(QEvent*) + 170 11: 11 QtGui 0x0000000106fb840c QApplicationPrivate::notify_helper(QObject*, QEvent*) + 252 12: 12 QtGui 0x0000000106fba357 QApplication::notify(QObject*, QEvent*) + 2919 13: 13 QtCore 0x0000000106c75516 QCoreApplication::notifyInternal(QObject*, QEvent*) + 118 14: 14 QtGui 0x0000000106fb8df6 QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) + 470 15: 15 QtGui 0x0000000106f67a2a qt_mac_handleMouseEvent(NSEvent*, QEvent::Type, Qt::MouseButton, QWidget*, bool) + 922 16: 16 AppKit 0x00007fff9491f145 -[NSWindow sendEvent:] + 781 17: 17 QtGui 0x0000000106f5f2f1 -[QCocoaWindow sendEvent:] + 113 18: 18 AppKit 0x00007fff948c05d4 -[NSApplication sendEvent:] + 2021 19: 19 QtGui 0x0000000106f640fe -[QNSApplication sendEvent:] + 78 20: 20 AppKit 0x00007fff947109f9 -[NSApplication run] + 646 21: 21 QtGui 0x0000000106f6cba0 QEventDispatcherMac::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 528 22: 22 QtCore 0x0000000106c728ad QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) + 477 23: 23 QtCore 0x0000000106c75ac7 QCoreApplication::exec() + 199 24: 24 kwindowtest 0x0000000105e33bdc main + 316 25: 25 libdyld.dylib 0x00007fff93bb75fd start + 1 26: 26 ??? 0x0000000000000002 0x0 + 2 ``` - René J.V. ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://git.reviewboard.kde.org/r/121213/#review70796 ----------------------------------------------------------- On Nov. 24, 2014, 7:37 p.m., René J.V. Bertin wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://git.reviewboard.kde.org/r/121213/ > ----------------------------------------------------------- > > (Updated Nov. 24, 2014, 7:37 p.m.) > > > Review request for KDE Software on Mac OS X and kdelibs. > > > Repository: kdelibs > > > Description > ------- > > This patch adapts the parser in `maybeDemangledName` to the backtrace > obtained in `kRealBacktrace` on OS X. > > > Diffs > ----- > > kdecore/io/kdebug.cpp 872a05a > > Diff: https://git.reviewboard.kde.org/r/121213/diff/ > > > Testing > ------- > > Works as expected on OS X 10.9.4 . > > > Thanks, > > René J.V. Bertin > >
