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From: Bryan M. <om...@br...> - 2006-09-08 21:04:40
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hmmmmm. compiling the C++ program with -D_GLIBCXX_DEBUG showed the code to have bad initialisers for a couple of iterators (I really recommend this compile time define - its great!). I haven't been able to recreate this fault with a small program yet but it is interesting because the original program ran OK both on its own and within Memcheck. I will keep trying to get to the bottom of this but if you have C++ programs using the STL and they go bang under Omega, see if they abort when running them normally but after compiling with the above define set. (If they do abort when running normally, start them inside gdb and it will give you a useful stack trace to help you sort out your naughty code :P). If anyone can find a trivial example that causes Omega to go bang but not Memcheck, I would really appreciate it if you would post it to the list. for information: $> rpm -qa | grep libstd libstdc++-devel-4.1.0-25 libstdc++-4.1.0-25 compat-libstdc++-5.0.7-21 This is on Suse 10.1, x86_64. thanks in advance and happy hunting, Bryan "Brain Murders" Meredith Bryan Meredith wrote: > Just found an interesting bug in the new function return tracking when > using C++. Don't think that C will be affected as you can't do anything > like the stuff you can do inside a class constructor. > > Any C++ users out there getting an error like this before your program > actually even gets into main() ?: > > ==4018== Process terminating with default action of signal 11 (SIGSEGV) > ==4018== Access not within mapped region at address 0xFFFFFFFFFFFFFFF8 > > If so, I'm on it and hope to have a proper solution in the next day or > two (I'm ill at the moment so things have slowed down a bit). I know > what it is but I will be chatting with the guys on the developer list to > get a proper solution together that will always work. > > Sorry for the inconvenience, > Bryan "Brain Murders" Meredith > > Bryan Meredith wrote: >> Fellow Valgrinders, >> >> please see http://www.brainmurders.eclipse.co.uk/omega.html for a >> complete overview of what this tool can do for you! >> >> (We use this heavily at work - feel free to give it a spin...) >> >> >From the web page: >> ================== >> Omega addresses what I perceive to be one of the few shortfalls of the >> excellent Valgrind Memcheck Tool - where Memcheck reports the location >> that a leaked block was allocated, Omega also shows where it was leaked. >> >> >> New in Beta5: >> ============= >> Aggregates the circular references together into common contexts, giving >> a repeat count and leak amount for that context and makes display optional. >> Broke the debugger attach :( >> On the positive side, it gives much more accurate leak reports in some >> cases, having finally closed off some edge cases with functions that >> return values. >> A reported bug with realloc() on x86 (not x86-64) was also fixed (thanks >> for the report). >> Exposed some internal sizing information for users with HUGE programs to >> tweak for potentially faster execution. >> >> The next patch is likely to be a release candidate unless you find me >> some juicy bugs to chomp on. >> >> >> Known Issues: >> ============= >> I have a wrapper around main() to detect when to stop tracking - if you >> are using threads and they don't exit before main() does, there will be >> problems. I haven't particularly tested this with threads yet - that's >> targeted for the later on. It can also affect the stack trace slightly. >> >> >> Requested Features? >> =================== >> I am still toying with the idea of allowing targeted tracking through >> the use of the suppression system - >> >> exclusively report on a specified malloc() call. >> show hanging pointers at a targeted call to free(). >> turn on more verbose output for a given memory block. >> >> Generate leak reports in some XML format to make machine parsing simple. >> >> >> If you use Omega and think any of these features would be useful or have >> requests of your own, please let me know. >> >> >> As ever, I would welcome your comments, bug reports and especially any >> news of success stories. Please share them with us on the list and copy >> me in so I don't miss them. >> >> thanks and happy hunting, >> Bryan "Brain Murders" Meredith >> >> >> >> ------------------------------------------------------------------------- >> Using Tomcat but need to do more? Need to support web services, security? >> Get stuff done quickly with pre-integrated technology to make your job easier >> Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo >> http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 >> _______________________________________________ >> Valgrind-developers mailing list >> Val...@li... >> https://lists.sourceforge.net/lists/listinfo/valgrind-developers >> > > ------------------------------------------------------------------------- > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > Valgrind-developers mailing list > Val...@li... > https://lists.sourceforge.net/lists/listinfo/valgrind-developers > |