i want to debug something in glibc, so i want to use a debug version of glibc to build the program.
if i just use "gcc -o test test.c" to build the program,
apt-get install libc6-dbg
apt-get source libc6-dev
when i was debugging the programs,some val is told that it is optimized. and EIP is always jump back.
how can i debug the debug version of glibc.
Caveat: I use fedora but it has a similar mechanism.
The debug package downloads an additional file that has the debug information you would get if you compiled with -g for glibc.
But, this package matches the standard build which is built with optimization (e.g. -O2).
It's the optimization that is causing the behavior you're seeing. So, the gdb "coverage" will be spotty.
What you want is a glibc version that is built with -gdwarf-2 and -O0. AFAIK, you'll have to get that by building glibc yourself from the source.
You'll probably have to run the configure script and select the -g and -O options for the build. Then, run make. The exact details should be in the source documentation [or online] somewhere.
Then, you'll have to [forcibly] link your program against the built-from-source version.
Related
I'm currently compiling sources using --coverage, with GCC. The generated .gcno files (and the instrumented libraries) are to be packed in a RPM and the code coverage evaluated on another, target platform.
Now, I'm having a problem getting the coverage data, because when I run the programs calling the instrumented code, I get messages telling me that I have a version mismatch. They look like:
".gcda:Version mismatch - expected A85R got B12R"
Now, I've seen this question: GCOV Version mismatch - expected 700e got 408R which says I must use the same toolchain when compiling and when executing the code.
I'm compiling using gcc 11.2.1, and gcov --version says the same thing, on the source platform.
On the target platform, gcc --version and gcov --version both give that very same version number.
The compiling and the testing is done on the same "physical" machine, but on different Docker containers. On both of them, the GCC version and gcov version are the same
I've done further testing: even on the Docker container where we compile, we cannot run the coverage, and get the same error. Or, to be more precise, when compiled using gcc 11, it will say "version mismatch". However, when compiled using gcc 8.5, it works.
The setup is that we have the GCC 11 toolset, which requires gcc 8.5 to install. By default, gcc 8.5 is enabled, and you have to use a script (provided by the gcc 11 toolset) to enable the later. That script updates different variables, like the PATH, LIBRARY_PATH, etc., to look at GCC 11 first.
However, I'm pretty sure it doesn't upgrade the libc.so library, and that it's the cause of the problem: I compiled two of our simplest libs (each of them having no dependencies whatsoever, except libc) with gcc 11, in coverage mode. Then I compiled a simple test program, without coverage, calling some functions from the two instrumented libs. I checked (with elfread -d), the program only links to these two libs (and libc).
Calling this test program while on the compilation container results in the Version mismatch error, which would lead me to conclude that our libc.so isn't compatible with gcc 11.
I wonder if there is a way to get a "native" gcc 11, instead of a "toolkit" package which has to be installed over a gcc 8.5 (my colleague in charge of creating the Docker containers tells me that for gcc 9 and above, there are only "toolkit" packages, requiring gcc 8.5 to install).
Our target architecture runs on Rocky Linux, and I think our development architecture is a Redhat, if it has any importance here.
When using clang v8.0.0 on Windows (from llvm prebuilt binaries) with -g or -gline-tables-only source map tables are not being picked up by gdb or lldb debuggers.
Upon including -g flag file grows in size (which is to be expected) yet neither gdb nor lldb pickes the source up
When compiled with gcc though (with -g flag) source files are detected by debugger.
I have tried running the same command (clang -g <codefile>) on macOS High Sierra (clang -v says it is Apple LLVM version 10.0.0 (clang-1000/10.44.4)) where there source files are being picked up by lldb. So I guessed it is localized to my windows instance or llvm for windows build.
P.S. output of clang -v on windows:
clang version 8.0.0 (tags/RELEASE_800/final)
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: C:\Program Files\LLVM\bin
On Windows, Clang is not self-sufficient (at least not the official binaries). You need to have either GCC or MSVC installed for it to function.
As Target: x86_64-pc-windows-msvc indicates, by default your Clang is operating in some kind of MSVC-compatible mode. From what I gathered, it means using the standard library and other libraries provided by your MSVC installation, and presumably generating debug info in some MSVC-specific format.
Add --target=x86_64-w64-windows-gnu to build in GCC-compatible mode. (If you're building for 32 bits rather than 64, replace x86_64 with i686). This will make Clang use headers & libraries provided by your GCC installation, and debug info should be generated in a GCC-compatible way. I'm able to debug resulting binaries with MSYS2's GDB (and that's also where my GCC installation comes from).
If you only have GCC installed and not MSVC, you still must use this flag.
How do I know this is the right --target? This is what MSYS2's Clang uses, and I assume they know what they're doing. If you don't want to type this flag every time, you can replace the official Clang with MSYS2's one, but I'm not sure if it's the best idea.
(I think they used to provide some patches to increase compatibility with MinGW, but now the official binaries work equally well, except for the need to specify the target. Also, last time I checked their binary distribution was several GB larger, due to their inability to get dynamic linking to work. Also some of the versions they provided were prone to crashing. All those problems come from them building their Clang with MinGW, which Clang doesn't seem to support very well out of the box. In their defence, they're actively maintaining their distribution, and I think they even ship libc++ for Windows, which the official distribution doesn't do.)
I am trying to install and run cmocka library for unit testing on Mac OSX Yosemite 10.10.3, but I've got some problems with the RPATH settings.
Update:
Thanks to #baf, I was able to include cmocka.h in my CMakeLists.txt manually like this:
set(CMAKE_C_FLAGS_DEBUG "-I/usr/local/include/cmocka.h")
However, why is it so that I have to do it manually?
I've already tried many different ways of installing it:
What I've done so far:
Download cmocka from here: here. Version 1.0.
tar xvf cmocka-1.0.1.tar.xz
cd cmocka-1.0.1, mkdir build and cd build
sudo cmake ..
I get a message like this here:
-- Configuring done
CMake Warning (dev):
Policy CMP0042 is not set: MACOSX_RPATH is enabled by default. Run "cmake --help-policy CMP0042" for policy details. Use the cmake_policy command to set the policy and suppress this warning.
MACOSX_RPATH is not specified for the following targets:
cmocka_shared
This warning is for project developers. Use -Wno-dev to suppress it.
Question #1: How can I set the rpath so that there is no warning like the one above?
sudo make
sudo make install
cmocka should be installed now, right?
Running cmake for my program which is using cmocka library.
So now I run cmake for my program and my main CMakeList.txt file has lines like this:
find_library (CMOCKA cmocka)
if (NOT CMOCKA)
message (WARNING "Cmocka library not found.")
endif (NOT CMOCKA)
But the warning doesn't show up during this phase, so I believe that find_libarary(CMOCKA cmocka) has successfully located cmocka on my computer.
Running make for my program.
While running make I get an error like this:
fatal error:<br>
'cmocka.h' file not found<br>
#include <cmocka.h>
^
1 error generated.
So I guess that cmocka cannot be found...
Question #2: Why cmocka library cannot be found?
Additional notes:
I've tried running
$ export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH
but it didn't helped. I guess it is a solution for Linux, not Mac.
I've tried to learn something about RAPTH on Mac in cmake from their official documentation here: http://www.cmake.org/Wiki/CMake_RPATH_handling. However I understood very little and I wasn't able to come up with a solution for my problem.
I've tried installing cmocka using brew but I got the same result.
Moreover, I've read many questions at SO about RPATH, linking and cmocka, but I couldn't find a suitable solution as well. Nevertheless, here is the list of related threads:
How to set the runtime path (-rpath) of an executable with gcc under Mac OSX?
https://stackoverflow.com/questions/29721183/getting-undefined-symbols-for-architecture-x86-64-when-trying-to-build-on-osx
How to configure scons to link using rpath on mac?
mariadb install failure: make (Mac OSX 10.6.8)
I've run otool -L cmocka. Here's what I got:
error: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/otool: can't open file: cmocka (No such file or directory)
I was able to successfully compile my program (thanks to baf) when I added the -I/usr/local/include flag to my debug flags:
set(CMAKE_C_FLAGS_DEBUG "-std=gnu99 -Wall -pedantic -g -I/usr/local/include/cmocka.h")
I'd like to implement some features of libgcrypt in my program, but it is currently running on Windows, OSX, and Linux (Arch/Xubuntu), so I can only really do so if I can build it for all three platforms. On OSX and Linux I had no problem.
I got the sources from the github page for libgcrypt and libgpg-error, and I've successfully built and run the libraries on both Linux and OSX, so I know that my test code is valid (which I am now having trouble with on Windows w/MinGW).
I did the following on Xubuntu (and similar on Arch but using pacman instead of apt-get):
sudo apt-get install mingw32 mingw32-runtime mingw32-binutils
to get the cross compiling tool chain and
git clone https://github.com/Chronic-Dev/libgcrypt.git
git clone https://github.com/Chronic-Dev/libgpg-error.git
cd libgpg-error
autoreconf -vfi
./autogen.sh --build-w32
make
sudo make install
cd ../libgcrypt
autoreconf -vfi
./autogen.sh --build-w32
make
sudo make install
to build, and it successfully builds these files in home/myuser/w32root/:
libgcrypt.a
libgcrypt.def
libgcrypt.dll.a
libgcrypt.la
libgpg-error.dll.a
libgpg-error.la
include/
gcrypt.h
gcrypt-module.h
gpg-error.h
I took these files over to windows, and tried compiling the test code (named main.c locally) with
gcc main.c -o main.exe -lgcrypt
but I get undefined reference errors leading me to the conclusion that the library wasn't linked correctly (initially only using libgcrypt.a), so I looked some stuff up, and found that some libraries require a set of files like .a, .def, et al. to work, so I dropped them all in C:\Mingw\lib to see if it made a difference; it didn't. The following was also silent in finding the library file to link, but didn't resolve the undefined references:
gcc main.c -o main.exe -lgcrypt -lgpg-error
So I'm not really sure where to go from here. The readme doesn't get into cross compiling too much, like what files to copy and link once you're on the Windows side. Any pointers (to docs for it I missed maybe?) are appreciated! Thanks a bunch for reading my wall of text.
I am having some trouble compiling 32-bit GTK+ applications on 64-bit Linux, specifically Ubuntu 10.04. Compiling 64-bit GTK+ applications works fine, and everything is set up to compile 32-bit apps as well, but it doesn't work with GTK+
I have a very simple test program that I am using for trouble shooting that is simply a gtk_init and a gtk_main, which compiles fine as -m64. I am compiling with gcc 4.6.2, calling it with:
gcc -m32 gtktest.c `pkg-config --cflags gtk+-2.0` `pkg-config --libs gtk+-2.0`
These are the two different kinds of error messages I get:
/usr/local/lib/gcc/x86_64-unknown-linux-gnu/4.6.2/../../../../x86_64-unknown-linux-gnu/bin/ld: warning: libXext.so.6, needed by /usr/lib/../lib32/libgtk-x11-2.0.so, not found (try using -rpath or -rpath-link)
and
/usr/lib/../lib32/libgdk-x11-2.0.so: undefined reference to `XmbSetWMProperties'
Keep in mind that these aren't the only errors, I just included the two specific types for reference and to keep it short, I get errors for the whole stack of GTK+ libraries.
I do have all of the proper 32-bit versions of the libraries in my lib32 folders.
Hopefull someone has had this problem before and can help me, this is really causing me quite the headaches, and I can't fine much help any where on the net.
Please ask if there is any other information you need me to provide to help with diagnosing this problem.
Note: I do have the ia32-libs and gcc-multilib packages. Ubuntu 10.04 does not have a separate ia32-libs-gtk packages, but I think these are wrapped in to the ia32-libs packages. They all are present on my system.
I think this must be some sort of linker config problem. I've recently built the new Free Pascal compiler and a 32 bit cross compiler, and I also upgraded GCC to 4.6.2 to take advantage of some of the new C++ features and fixes to C99 support. The default 4.4.3 GCC still exists on my system. Where I think the problem has been introduced is when I installed a new binutils because I've been experimenting with Clang and LLVM as a toolchain, and I wanted and ld with plug-in capabilities, so I figured might as well upgrade them all.
Everything works fine compiling 64 bit programs, there hasn't been a single problem with the new tools at all, and I can compile 32-bit programs but when it comes time to explicitly link something in I have problems.
I know my current set of libs is appropriate, and I have Free Basic installed which only emits 32 bit code, and I was able to build 32-bit GTK+ programs no problem before this upgrade.
Just wondering if anyone has any ideas what configs might have been changed in this upgrade or has had this happen to them before? I really should upgrade to a newer distro so I can take advantage of all the new software with out have to hack up all of my packages, but unfortunatly there is a bug in the newer kernels that prevents my computer from coming back from standby, and this is a laptop I use for personal side projects, so proper power management is pretty important, and it's not a huge loss if I bork the system, other than I have it set up pretty much perfect for my workflow.
You may tell pkg-config to search for the 32-bit libraries with the environment variable PKG_CONFIG_PATH.
For Ubuntu:
export PKG_CONFIG_PATH=/usr/lib32/pkgconfig:$PKG_CONFIG_PATH
For Redhat:
export PKG_CONFIG_PATH=/usr/lib/pkgconfig:$PKG_CONFIG_PATH
I think you need to install the ia32-libs-gtk & gcc-multilib packages, and you need to compile and link with gcc -m32 as you already do.
The GTK package in 12.04 doesn't seem to work correctly with multiarch. You can work around this on Ubuntu 12.04 by creating the following symlinks:
sudo ln -s /lib/i386-linux-gnu/libglib-2.0.so.0 /usr/lib32/libglib-2.0.so
sudo ln -s /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0 /usr/lib32/libgtk-x11-2.0.so
sudo ln -s /usr/lib/i386-linux-gnu/libgdk-x11-2.0.so.0 /usr/lib32/libgdk-x11-2.0.so
sudo ln -s /usr/lib/i386-linux-gnu/libatk-1.0.so.0 /usr/lib32/libatk-1.0.so
sudo ln -s /usr/lib/i386-linux-gnu/libpangox-1.0.so.0 /usr/lib32/libpangox-1.0.so
sudo ln -s /usr/lib/i386-linux-gnu/libpango-1.0.so.0 /usr/lib32/libpango-1.0.so
sudo ln -s /usr/lib/i386-linux-gnu/libgmodule-2.0.so.0 /usr/lib32/libgmodule-2.0.so
sudo ln -s /usr/lib/i386-linux-gnu/libgobject-2.0.so.0 /usr/lib32/libgobject-2.0.so
sudo ln -s /usr/lib/i386-linux-gnu/libgdk_pixbuf-2.0.so.0 /usr/lib32/libgdk_pixbuf-2.0.so
I found the answer in this thread: http://www.blitzbasic.com/Community/posts.php?topic=101357
Alternatively (probably better), you can leave the base system untouched and update your link to search by file name instead of library name. Something like:
gcc -m32 gtktest.c `pkg-config --cflags gtk+-2.0` -L/usr/lib/i386-linux-gnu -l:libgio-2.0.so.0 ...
This isn't great. You'll have to add a -l: for each library that the linker can't find and your build will break if the library file name ever changes.