I'd like to cross-compile Boost for ARM. Here is some documentation.
Where can I find the file user-config.jam? I don't see it anywhere. Is it something I have to create in the boost root directory?
As the documentation says, this file must be in one of these paths (on Linux) : $HOME or $BOOST_BUILD_PATH. If not, you seem to have to create it.
If it doesn't find user-config.jam, site-config.jam is used.
You can use the --debug-configuration option to find which
configuration files are actually loaded.
Inside the boost source code folder, just run the command:
find . -name user-config.jam
It seems to be
./tools/build/v2/user-config.jam
Related
We have one build machine which has some static libraries at unusual paths, and gcc doesn't find them when via the -l option, all other build machines run fine. But it seems this one configured incorrectly or something.
The solutions we have tried:
Check the host name of the build machine in build script and add the -L command line option if it matches name the problematic build machine (very ugly).
Print the list of search dirs using the -print-search-dirs option
and symlink the problematic library into the first one (too hackish).
What I would like to do is simply add an extra path to search paths system wide to the gcc.
Is there a way to change/configure the default library search paths in GCC? Is there a config file where the list of the defaults are stored?
You can use
-l:<PATH_TO_YOUR_LIBRARY>
Or you can set up the /etc/ld.so.conf with the path to your directory of which you have the shared library installed. You might have to run ldconfig after that.
The title states the problem statement: I'm trying to create a CMake project utilizing the libwebsocket library, but I can't find any information for doing so.
Is there anyone who have tried this? A simple CMakeLists.txt for e.g. the test-server program would be much appreciated!
I've compiled and installed the library on my Ubuntu 14.04 machine.
EDIT: I would also like to know if anyone has experience in using the libwebsocket lib w/ C++?
EDIT 2:
After using #evadeflow's answer I'm able to run cmake and build the project. However now I get the following runtime error:
And here's an ls of the /usr/local/lib/ folder
It seems like the libwebsockets.so.7 file is not found?
From CMake:
${LIB_WEBSOCKETS_INCLUDE_DIRS} = /usr/local/lib
${LIB_WEBSOCKETS_INSTALL_DIR} = /usr/local
EDIT 3:
Solved edit 2 by:
Editing the file /etc/ld.so.conf and add /usr/local/lib.
Reference: https://lonesysadmin.net/2013/02/22/error-while-loading-shared-libraries-cannot-open-shared-object-file/
If you've already installed libwebsockets, something like this ought to work:
cmake_minimum_required(VERSION 2.8)
find_package(PkgConfig)
pkg_check_modules(LIB_WEBSOCKETS REQUIRED libwebsockets)
get_filename_component(
LIB_WEBSOCKETS_INSTALL_DIR
${LIB_WEBSOCKETS_LIBRARY_DIRS}
DIRECTORY
)
add_executable(
test-server
test-server/test-server.c
test-server/test-server-http.c
test-server/test-server-dumb-increment.c
test-server/test-server-mirror.c
test-server/test-server-status.c
test-server/test-server-echogen.c
)
target_link_libraries(
test-server
${LIB_WEBSOCKETS_LIBRARIES}
)
set_target_properties(
test-server
PROPERTIES
INCLUDE_DIRECTORIES
${LIB_WEBSOCKETS_INCLUDE_DIRS}
LINK_FLAGS
"-L${LIB_WEBSOCKETS_LIBRARY_DIRS}"
COMPILE_DEFINITIONS
INSTALL_DATADIR="${LIB_WEBSOCKETS_INSTALL_DIR}/share"
)
This is basically a stripped-down version of what's in the CMakeLists.txt file from the libwebsockets github project, without all the platform- and build-specific conditionals.
I hope this is enough to satisfy your request for a 'simple' CMakeLists.txt example. I tested it with CMake version 2.8.12.2; it should work fine as-is if you've installed libwebsockets to its default prefix of /usr/local; however, if you installed to a different location, you will need to set PKG_CONFIG_PATH in the environment from which you invoke cmake.
Also, as explained in the CMake documentation, you will need to replace DIRECTORY with PATH in the get_filename_component() invocation if you're using CMake 2.8.11 or earlier.
UPDATE: Regarding the file not found error from your follow-up comment, this is almost certainly due to libwebsocket.so[.7] not being on the linker's default path. There are at least three ways to fix this, but the easiest way to verify that this is the problem would be to just launch the app from the terminal using:
$ LD_LIBRARY_PATH=/usr/local/lib ./test-server
If it works, you know that was the issue. (Oops—I see you've figured it out in the meantime. Yeah, updating /etc/ld.so.conf is another way. Or, you can force CMake to link to the static version of libwebsockets [as described in this answer] is another. But I like your solution best.)
UPDATE: One thing that wasn't mentioned about /etc/ld.so.conf is that you generally need to run sudo /sbin/ldconfig after editing it in order to update the shared library cache. And—when setting non-default paths for a particular application—many people consider it good form to add a new 'sub-config file' in /etc/ld.so.conf.d rather than edit the global ldconfig file. (For the case of adding /usr/local/lib, though, this is such a common requirement I'd be inclined to dump it in the global config, which is what lots of Linux distros do, anyway.)
I have two files in my project.
One is a ".c" file, one is a ".asm" file. First, I compile both the files into two ".o" object files and then link together using a custom linker script.
Currently, I am using a simple bash script with manual commands to build the project, but as the project size is expected to increase, I was thinking of moving the project to using cmake as its primary build system.
I have searched documentation of cmake and googled for a lot of time, although I have shortlisted some of the variables in cmake which might prove to be useful in this case, I am unable to find any sample explaining how to achieve this.
Can anybody provide me with a brief sample code on how should I go about achieving this ?
You asked for an example? Here's one from the cmake wiki
set(mySrcs foo.c bar.c)
set(can_use_assembler FALSE)
# test wether it is a x86 machine and as/gas is available
if("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "i.86")
enable_language(ASM-ATT)
if(CMAKE_ASM-ATT_COMPILER_WORKS)
set(can_use_assembler TRUE)
set(mySrcs ${mySrcs} codec_i86.s)
endif(CMAKE_ASM-ATT_COMPILER_WORKS)
endif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "i.86")
# no assembler found
if(not can_use_assembler)
set(mySrcs ${mySrcs} codec_generic.c)
endif(not can_use_assembler)
add_executable(player ${mySrcs})
Because of the way that CMake works, assembling and linking are grouped together in the same step (from the programmer's perspective at least). So add_executable automatically handles everything for you.
If you want to include a linker script, that gets more difficult with CMake. The best place to look into it is over here. Since the examples and instructions are too long to copy out in the SO answer box, I'll leave the reading to you.
I have a project whose source includes symbolic links to other source trees (notably, the CppUTest framework). I need to build a debian package out of my project, but dpkg-source will not follow the symbolic links.
Digging further, I believe this is because the default behavior for tar is not to dereference symbolic links unless explicitly told to (with -h).
I was unable to find a way to pass this extra option to tar when building the debian source tarball.
So what am I doing wrong here? Is it possible to build a debian source tarball whose origin includes symbolic links? If so, how?
As read in this thread.. http://ubuntuforums.org/showpost.php?p=9752860&postcount=3
They can be included in the package just like normal files.
The details depend on the way you're doing the packaging, but using something like the following in debian/rules's `install' target should work:
ln -s /usr/share/whatever/file/you/want $(CURDIR)/debian/<pkgname>/usr/whatever/place/you/want/the/link
Everything inside debian/ will end up inside the .deb, including the symlinks you put there.
Basic Question:
How can I get gcc to tell me where it searches for Ada includes?
Specific Problem:
I have just finished converting a C library's header files to Ada specs so that I can interface with the library using Ada. I now want to install the specs on my system. I also want to make the installation portable to some extent so that I can make install on any machine (and thus host the specs and Makefile on Github or similar). I'm just not sure where exactly to install the specs to.
gnat ls -v will give you the default search paths.
If you want to install your own Ada library, you should place a project file (.gpr) in the "Project Search Path", which will tell gnat where to find the ada and ali files and the library.
Normally, you will place the ada files in /usr/[local/]include/myadalib and the ali files in /usr/[local/]lib/myadalib and maybe link the .so file into /usr/[local/]lib, but you can put them anywhere you want. The important thing is to place the project file (myadalib.gpr) in the project search path.
You can even adjust the project search path by setting the ADA_PROJECT_PATH environment variable.