I'm using rust:1.67-buster to build my mixed Rust/C++ project in docker, for running on Debian.
When compiling a release with no debuginfo, my binary on Linux is 18mb. When I set
ENV RUSTFLAGS="-C link-args=-lstdc++ -C debuginfo=2 -C split-debuginfo=packed
I get dwp files inside the deps directory, and the executable is also 96mb.
If I remove even split-debuginfo, the binary goes up to 145mb, so it's doing something. But that still seems awfully large.
If I add -C strip=debuginfo then my executable size goes down to 9mb and I still have the dwp files in the deps/ subdirectory, but obviously gdb doesn't know where to look for them.
Isn't the point of -C split-debuginfo=packed that I shouldn't need the extra strip command?
Related
So I got several shared libraries that I am trying to permanently install on my Ubuntu system but I am having some difficulty with it.
I want to install the libraries and the headers in a separate folder under /usr/local/lib and /usr/local/include (for example a folder named agony) so it would be clean and removing them would just require that I delete those folders. so it looks something like this:
/usr/local/lib/agony/libbtiGPIO.so
/usr/local/lib/agony/libbtiDSP.so
...
/usr/local/include/agony/GPIO.h
/usr/local/include/agony/DSP.h
...
And I added a file here /etc/ld.so.conf.d/agony.conf which include a line describing the path to the library folder:
$ cat /etc/ld.so.conf.d/agony.conf
/usr/local/lib/agony
and I perform sudo ldconfig to update the library database.
So to double check if the library is found I do ldconfig -p | grep bti* and
I see the following result:
$ ldconfig -p | grep bti
...
libbtiGPIO.so (libc6,x86-64) => /usr/local/lib/agony/libbtiGPIO.so
libbtiDSP.so (libc6,x86-64) => /usr/local/lib/agony/libbtiDSP.so
...
At this point I should be able to use the libraries without specifying the library path. But When I attempt to compile an application without providing the library path (-L) it fails. However, when I supply gcc with the library path ex:
gcc source.c -L /usr/local/lib/agony output -lbtiGPIO -lbtiDSP
it works!!
I don't want to use LD_LIBRARY_PATH environment variable because this library is going to be used everywhere on the system and I don't want other compilers to worry about providing LD_LIBRARY_PATH.
What am I doing wrong here?
At this point I should be able to use the libraries without specifying the library path
Here lies the confusion.
You have built your shared library libbtiGPIO.so (just sticking with that one),
placed it in /usr/local/lib/agony, and updated the ldconfig database accordingly.
The effect of that is when you run a program that has been linked with libbtiGPIO
then the dynamic linker (/lib/x86_64-linux-gnu/ld-2.21.so, or similar) will know where to look
to load that library into the process and you will not need to tell it by setting an LD_LIBRARY_PATH in the environment.
However, you haven't done anything that affects the list of default library
search directories that are hardwired into your build of gcc, that it passes to
the linker (/usr/bin/ld) when you link a program with libbtiGPIO in the first place.
That list of default search directories is what you will find if your do a verbose
build of your program - gcc -v ... - and then pick out the value of LIBRARY_PATH
from the output, e.g.
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/5/:\
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/:\
/usr/lib/gcc/x86_64-linux-gnu/5/../../../../lib/:\
/lib/x86_64-linux-gnu/:\
/lib/../lib/:\
/usr/lib/x86_64-linux-gnu/:\
/usr/lib/../lib/:\
/usr/lib/gcc/x86_64-linux-gnu/5/../../../:\
/lib/:\
/usr/lib
/usr/local/lib/agony is not one of those and to make it one of those you
would have to build gcc from source yourself. Hence, in order to link your
program with libbtiGPIO you still need to tell ld where to find it with
-L/usr/local/lib/agony -lbtiGPIO.
man, you misunderstand the procedure of complier and link.
First, libbtiGPIO.so is a shared link library not a static link library. it is important to know those difference .
Then you need to know something else. changing ld.so.conf.d/*.conf and run sudo ldconfig, it affects the procedure of link. in other words, if you don't add agony.conf and sudo ldconfig, you will receive a error when you run ./a.out rather than gcc source.c -L ...., the gcc command can run successfully even thougth you don't ldconfig.
Finally,if you don't pollute the LD_LIBRARY_PATH environment variable, you have to add -L ... options in your gcc command. What'more, if you don't want to input too many words in your shell frequently, you can learn to use Makefile.
I am cross-compiling 3.4.0 kernel for an embedded device. Then I would like to install compat-wireless drivers which require /lib/modules/3.4/build directory and sub-files. Could anyone explain how can I build that directory so that when I do INSTALL_MOD_PATH=newmodules make modules_install it would load /lib/modules/$(uname -r)/build directory as well? I would appreciate for a clear explanation.
I am using debian distro. I know I can install the kernel headers by apt-get install linux-headers-$(uname -r), but I doubt it would be a good idea since the kernel sources might not be identical.
Typically /lib/modules/$(uname -r)/build is a soft-link to the directory where performed the build. So the way to do this is to simply do a
make modules_install INSTALL_MOD_PATH=/some/root/
in the build directory of the kernel where /some/root is where you want your cross compile pieces to end up. This will create a link to your kernel build path in /some/root/lib/modules/$(uname -r) ... verify that.
Now when you build the compat_wireless drivers specify the kernel build directory in the Makefile as /some/root using the KLIB_BUILD variable (read the Makefile)
make modules KLIB_BUILD=/some/root/lib/modules/$(uname -r)/build
this should do the trick for you.
EDIT A
In answer to your comment below:
Keep "newmodules" outside the kernel directory it's a bad idea to put it in the kernel directory. so mkdir newmodules somewhere like /home/foo or /tmp or something. This is one of the reasons your build link is screwed up
ALSO .../build is a soft link /to/kernel/build/location it will only copy over as a soft-link. You also need to copy over the actual kernel source / kernel build directory to your microSD, using the same relative location. For example,
Let's say your kernel source is in:
/usr/src/linux-3.5.0/
Your kernel build directory is:
/usr/src/linux-3.5.0-build/
Your newmodules (after following 1.) is in:
/tmp/newmodules/
So under /tmp/newmodules/ you see the modules installed in a tree like:
lib/modules/$(uname -r)/
when you do an ls -al in this directory, you'll see that build is a soft link to:
build -> /usr/src/linux-3.5.0-build/
Now let's say your microSD is mounted under /mnt/microSD
then you need to do the following
mkdir -p /mnt/microSD/usr/src
cp -a /usr/src/linux-3.5.0 /usr/src/linux-3.5.0-build /mnt/microSD/usr/src
cp -a /tmp/newmodules/lib /mnt/microSD/lib
Now you have all the content you need to bring over to your embedded environment. I take it you are doing the compat_wireless build on your target system rather than cross compiling it?
NOTE
If your kernel build is the same as the kernel source then just copy over the kernel source and ignore the linux-3.5.0-build in copy instructions above
This is old, but some people will need this information.
I have spent many hours to figure out where build folder comes from, and why it is just a link when I compile my own kernel. Finally figured it out;
Linux kernel usually just links the build and source folders to the source folder.
But!
Arch linux (probably some other distros too); has a manual script for deleting those links, and adding (filtered) files to build folder.
https://git.archlinux.org/svntogit/packages.git/tree/trunk/PKGBUILD?h=packages/linux
I've extracted that script to work standalone (in a kernel source tree) here: https://gist.github.com/furkanmustafa/9e73feb64b0b18942047fd7b7e2fd53e
I was able to generate an executable using
gcc myexec -o obj1.obj -o obj2.obj ...and link xxx.dylib
I deploy myexec to a different machine. myexec, ofcourse, would need xxx.dylib to run.
For that, I create myInstallFolder with xxx.dylib and myexec
On deployment, I was able to make myexec pick xxx.dylib by setting DYLD_LIBRARY_PATH point to myInstallFolder.
However, I want to avoid using DYLD_LIBRARY_PATH.
What change should be done at compilation/linking to make myexec pick up from myInstallFolder?
~Ryder
You can instruct the linker to write a path into the binary that the loader will use to load .so files:
-Wl,-R<path to myInstallFolder>
For example
-Wl,-R/usr/local/mybin/lib
I'm trying to install GCC into /my/custom/path/gcc
but for some reason it installs into the normal installation path.
the commands i'm using:
configure --target=i686-pc-linux-gnu --disable-nls --enable-languages=c,c++ --without-headers
make DESTDIR=/my/custom/path/gcc
make DESTDIR=/my/custom/path/gcc install
What am I doing wrong?
You should run (in a new build tree outside of the source tree)
/your/source/path/to/gcc/configure --target=i686-pc-linux-gnu --prefix=/my/custom/path/gcc ...
and then GCC will become installed in /my/custom/path/gcc/bin/ with include files in /my/custom/path/gcc/include/, libraries in /my/custom/path/gcc/lib/ etc etc
I suggest using /opt/ or $HOME/pub as your prefix and you might also be interested by the --program-suffix=-foo option
(do that in a fresh new build tree outside of the source tree; your previous one is rotten)
After successive compilation with make, you can run in your build tree
make install DESTDIR=/tmp/mygccinst/
and finally, you can copy the definitive files with something like
cp -va /tmp/mygccinst/ /
You may need to run this copy as root...
PS the installation prefix is built-in the gcc driver binary, which actually runs cc1 or cc1plus etc...
How can I store GNU make & configure files elsewhere? I have a project I am working on that I get compiled using:
./configure --prefix=/usr && make && su -c 'make install'
The thing is I don't want to pollute the current folder, which is a svn/git/hg/whatever sandbox with files generated by that command. I want to put those files in a separate location. I don't know if it's similar, but when I compile the linux kernel from source, I can specify where to put the ouput by passing the 'O' option to 'make', something like this:
make O=/home/user/linux-output
The Makefile must support this feature.
I think the autoconf generated makefiles all support the following use:
mkdir ../build
cd ../build
../configure --prefix=/usr
make
make install
(It's certainly recommended for gcc builds).
As Kristof already pointed out, GNU autotools inherently support out out-of-tree builds at the configure level.
So you can have the Makefile and built binaries out of the source tree trivially.
To get all the auto-generated artefacts out of the source tree requires much more work however.
We have a script that copies changes from a source tree into a working_copy, carefully preserving the configure script etc in the working_copy, which allows the original source tree to be pristine. However it's very inefficient, so I wouldn't recommend it.
I would recommend a normal out-of-tree build, and then explicitly excluding the remaining auto-generated files in the source tree.