I'm working on a relatively old Centos system where I am restricted in the packages I can install. I needed a newer version of gdb, so I built that successfully from source in my home dir. This gdb steps through my code fine, but I am looking for trouble that is manifesting in the C++ allocator (mt_allocator.cc) and this new version of gdb can't step through that code. I can break successfully on a function there:
break '__gnu_cxx::__pool<true>::_M_initialize()'
but when that breakpoint hits and I try to step through the code, gdb tells me:
Single stepping until exit from function _ZN9__gnu_cxx6__poolILb1EE13_M_initializeEv,
which has no line number information.
I tried using the dir command within gdb to add the path to where mt_allocator.cc is, but that had no effect.
What do I need to tell gdb so it can find those files?
Ah, found it. The Centos package manager put the debug files for the STL code at /usr/lib/debug. So:
set debug-file-directory /usr/lib/debug
within gdb gets it done.
Related
I have built openJDK the debugging version with the following configuration options in README-builds
bash ./configure ---with-debug-level=slowdebug --with-target-bits=64
However I cannot set any breakpoints or to be correct there are no symbols, doing some reseach on google I have found out that I should extract .diz (libjvm.diz) files in lib folder, but this does not seem to work.
I will answer this for other people, after you get the sources
Follow the steps:
bash ./configure --with-debug-level=slowdebug --with-target-bits=64 --disable-zip-debug-info
make all
An information worth mentioning that finally when you start the debugging session with gdb and you run the program you may see a SEGFAULT ignore it and continue till gdb stops at your breakpoint.
My knowledge and experience in programming is still very fresh and basic, so please bear with me.
I want to be able to use C++ on my MacBook (OS 10.9.5 Mavericks) via Eclipse, which I have already been using for Java previously.
So I followed the instructions in Eclipse GDB MacOSX Mavericks
to get GDB, but now I still need the GDB command file (.gdbinit), which I can't find anywhere (I tried which .gdbinit on Terminal to no avail).
Please help me.
.gdbinit is a configuration file. You won't have one unless you've downloaded one or written one separately. It goes in your home directory and just contains a list of commands to run on startup. You don't necessarily need one. See this answer: .gdbinit file missing
However, if you are fairly new to programming, I'd suggest starting with Xcode, Clang and LLDB on the Mac for C++ rather than Eclipse, GCC and GDB. It's far easier to get setup, and well documented.
See:
How do I set up a C++ project in Xcode 4?
I'm debugging some Fortran code with gdb and it keeps stepping through the C code for intrinsic Fortran functions. For example if I try to step past a write call, it jumps into write.c. Is there any way to stop this behaviour? I'm on CentOS 6.3, with gdb 7.2 and gfortran 4.4.
Normally I think "next" should work. But I don't know Fortran, maybe something funny is going on.
Another way is to ensure that you don't have debug info for the intrinsics installed. gdb will automatically skip over functions that don't have debuginfo if you try to "step" into them.
The final way is to upgrade your gdb and use the new "skip" command, which was added exactly for this use case.
I had a problem like this where next wasn't working when I was remote debugging on a cross-compiled target. I finally realized that I had loaded the wrong executable/symbol table using gdb's file command. Hitting next was jumping in to places un-releated to the current line of code. It was doing the best it could given the information I gave it :)
Say I am in IPython (e.g. on the new QT console), and that I call a C++ library that I wrote from it (e.g. using SWIG or Boost.Python). I would like to set a breakpoint in my C++ code and have the ability to interact with my C++ workspace (i.e. my variables when I hit the breakpoint) with IPython (e.g. plot my C++ variables, etc.).
In other words I would like to debug my C++ code from IPython. Is this at all possible? What are some tools I can use for this?
(assuming you are on Linux)
You just need gdb. First set up configuration telling gdb where your source files are by adding this to $HOME/.gdbinit:
directory absolute-path-to-source
Now start gdb python and on the gdb prompt do:
set args /usr/bin/ipython
run
You can't directly do gdb ipython because ipython is a script. Please refer to the gdb documentation from here on.
In general, you won't be able to debug C++ code directly with IPython. What you can do, though, is use a C++ debugger to debug your C++ code.
Essentially, you tell your C++ debugger to execute whatever process you need to use to run your code (this could be IPython itself), and set a breakpoint in your C++ code (your debugger will know to wait for the appropriate DLL to be loaded if it's in a DLL). From there, you are debugging your part of the code that is running in the IPython process.
We're using the Eclipse CDT 5 C++ IDE on Windows to develop a C++ application on a remote AIX host.
Eclipse CDT has the ability to perform remote debugging using gdbserver. Unfortunately, gdbserver is not supported on AIX.
Is anyone familiar with a way to debug remotely using Eclipse CDT without gdbserver? Perhaps using an SSH shell connection to gdb?
finally I got gdb run remotly anyhow now. At the Bug-symbol on the taskbar I took Debug Configurations - GDB Hardware Debugging.
In Main C/C++ Applications I set the full path on the Samba share of the executable (X:\abin\vlmi9506). I also set a linked folder on X:\abin in the project. Then I modified my batch-script in GDB Setup. It's not directly calling gdb in the plink-session but a unix-shell-script, which opens gdb. By this I have the possibility to set some unix environment-variables for the program before doing debug. The call in my batch:
plink.exe prevoax1 -l suttera -pw XXXXX -i /proj/user/dev/suttera/vl/9506/test/vlmi9506ddd.run 20155 dev o m
In the unix script I started gdb with the command line params from eclipse, that I found in my former tryals. The call in the shell command looks like this:
gdb -nw -i mi -cd=$LVarPathExec $LVarPathExec/vlmi9506
Then IBM just gives gdb 6.0 for AIX. I found version 6.8 in the net at http://www.perzl.org/aix/index.php?n=Main.Gdb. Our Admin installed it.
I can now step through the program and watch variables. I even can write gdb-commands directly in the console-view. yabadabadooooooo
Hope that helps to others as well. Can not tell, what was really the winner-action.
But each answer gives more new questions. Now I got 3 of them.
When I start the debug config I have to click restart in the toolbar to come really in the main procedure. Is it possible to come directly in main without restarting?
On AIX our programs are first preprocessed for embedded sql. The preprocessed c-source is put in another directory. When I duble-click the line to set a breakpoint, I get the warning "unresolved breakpoint" and in the gdb-console I see, that the break is set to the preprocessed source which is wrong. Is it possible to set the breakpoints on the right source?
We are using CICS on AIX. With the xldb-Debugger and the CDCN-command of CICS we manage that debugging is started, when we come in our programs. Is it possible to get that remotely (in plink) with gdb-eclipse as well?
I wouldn't normally take a shot in the dark on a question I can't really test the answer to, but since this one has sat around for a day, I'll give it a shot. It seems from looking at:
http://wiki.eclipse.org/TM_and_RSE_FAQ#How_can_I_do_Remote_Debugging_with_CDT.3F
...that even if the CDT has changed since that wiki page was made, you should still be able to change the debug command to:
ssh remotehost gdb
instead of using TM which uses gdbserver. This will probably be slightly slower than the TM remote debugging since that actually uses a local gdb, but on the other hand this way you won't have to NFS or SMB mount your source code to make it available to the local debugger (and if you're on a LAN it probably won't matter anyhow).
There's also a reference TCF implementation for linux, which you may or may not have any luck recompiling for AIX, but it allows for remote debugging if gdbserver is otherwise not available:
http://wiki.eclipse.org/DSDP/TM/TCF_FAQ
tried also to remotly debug an aix-appl with windows eclipse-cdt-gdb.
Got blocked at the end with unix/windows path-problems. Maybe my result can help u a little further - maybe you already got it work. I'm interested in your comment. asked on eclipse news portal- following the answer of martin oberhuber (thanks again) tried dsp dd (also blocked with path problem) and set an request in eclipse bugzilla.
here the link to news:
http://www.eclipse.org/newsportal/article.php?id=406&group=eclipse.dsdp.tm
Here my bugzilla:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=252758
At the moment we still debug localy with xldb but I am trying ddd-gdb at the moment. At least locally gdb is running.