I have the following CMakefile works well with CMake 2.8.12 but failed after upgrade to 3.9:
add_library(extlib STATIC IMPORTED GLOBAL)
set_property( TARGET extlib PROPERTY IMPORTED_LOCATION ${EXTERNAL_LIB_DIR}/extlib.a )
add_executable( myApp myApp.cpp )
target_link_libraries( myApp extlib)
cmake generates Makefile. But make failed:
/usr/bin/ld: ../../ext/lib/extlib.a(extlib.o): relocation R_X86_64_32S against `.rodata' can not be used when making a shared object; recompile with -fPIC
I run make VERBOSE=1 showing the following:
/usr/bin/c++ -rdynamic CMakeFiles/myApp.dir/myApp.cpp.o -o myApp -Wl,-rpath,/root/myApp/ext/lib ../../ext/lib/extlib.a
extlib.a is linked as a shared library.
The CMakefile has no problem with 2.8.12.
What do I need to modify to make it work in 3.9?
Thanks!
Related
I usually use gcc to compile my C program, it works ok, but when I tried to compile static library with -static parameter it always failed.
Although I tried some solutions on google, but it still didn't get fixed.
My command is as follows:
gcc mycode.c -static -L . -lurl -lcap -o mycode
The error message is:
/usr/bin/ld: cannot find -lc
collect2: error: ld returned 1 exit status
but when I remove -static it works very well.
GCC's -static linkage option directs the linker to ignore shared libraries
during the linkage. So it must find static versions of all the libraries required
by the linkage, including those that are linked by default, such as libc.
You have not installed the static version of libc (which would be /usr/lib/???/libc.a), so:
/usr/bin/ld: cannot find -lc
collect2: error: ld returned 1 exit status
libc.a is installed by the libc development package. The name of the libc
development package and how to install it depends on your distro. E.g. On Debian
or Ubuntu, the package to install is libc6-dev; on Fedora it is glibc-develop.
But before you go to do that, hang on a tick. You said:
I tried to compile static library with -static parameter it always failed.
gcc mycode.c -static -L . -lurl -lcap -o mycode
That sounds rather as if you just wanted to link your program with one or both
static libraries liburl.a, libcap.a, located in ./, and thought you should
do it by passing -static to the linkage.
There is no need to pass -static to link your program with ./liburl.a and/or
./libcap.a. The options:
-L . -lurl -lcap
will direct the linker to search in ./ for either of the files liburl.so (shared library)
or liburl.a (static library) and if it finds one or other of them it will link your
program with that library. If it finds both of them in ./, then it will choose the
shared library liburl.so. So unless you have ./liburl.so as well as ./liburl.a
then:
-L . -lurl
by itself will link your program against ./liburl.a.
And likewise for -lcap. No need for -static. The default shared library libc.so
will be linked automatically. The linker has no problem at all linking your program
with some static libraries and some shared ones. That is what is already happening
with your successful linkage:
gcc mycode.c -L . -lurl -lcap -o mycode
assuming that liburl.a and libcap.a are the only candidates for resolving
-lurl and -lcap in ./.
And even if you do have both ./liburl.a and ./liburl.so - and/or ./libcap.a and ./libcap.so - there is still no
need for a solution as drastic as a fully static linkage. You can just explicitly
tell the linker to find a particular static library if that's what you want, like:
gcc mycode.c -L . -l:liburl.a -l:libcap.a -o mycode
I thought of compiling Lua from source code and then create a C module.
I compiled Lua with success but I can't build my C module.
So, I compiled Lua like this:
gcc -o Lua *.c -Os -std=c99
Compiled my module like this:
gcc -Wall -shared -fPIC -o module.so -I. module.c
But there are a few errors here:
Undefined symbols for architecture x86_64:
"_lua_pushcclosure", referenced from:
_luaopen_module in module-fb0b1f.o
"_lua_pushnumber", referenced from:
_super in module-fb0b1f.o
"_lua_setglobal", referenced from:
_luaopen_module in module-fb0b1f.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
The C module itself:
#include "lua.h"
static int super(lua_State* L) {
lua_pushnumber(L, 5);
return 1;
}
int luaopen_module(lua_State* L) {
lua_register(L, "super", super);
return 0;
}
My Lua script:
require("module")
print(super())
I'm on Unix based system (Mac), but I want it to work on Linux as well.
Edit:
Problem to compile C module was fixed by entering -bundle -undefined dynamic_lookup instead of -shared (Thanks lhf).
But I can't import the module in Lua.
> require("module")
error loading module 'module' from file './module.so':
dynamic libraries not enabled; check your Lua installation
Another thing:
This seems to be a quick fix only; -bundle -undefined dynamic_lookup. This does not work on Linux. How can I do this on linux? I wanted a solution for Unix based systems.
Download Lua from lua.org and build Lua with make macosx. See Getting started.
Use -bundle -undefined dynamic_lookup instead of -shared to build module.so.
Use require"module" to load it into Lua.
Call super.
Make sure you're running the lua program that you have built above, not some other version that is installed.
I'm trying to write a very small, very simple project using PJSIP. But I'm already stuck on the first step, incorporating PJSIP in my project. I'm trying to build and compile on a Ubuntu 14.04 system using an arm-linux-gnueabihf-gcc cross compiler. For the coding itself I'm using Eclipse CDT, but the crosscompiling part is working in a normal order.
I downloaded de pjproject-2.3 folder to my system, configured it with this command:
./configure --host=arm-linux-gnueabihf CFLAGS='--sysroot=/home/david/rpi/rootfs' LDFLAGS='--sysroot=/home/david/rpi/rootfs'
The /home/david/rpi/rootfs folder is where I copied the rootsystem of my Pi. I then ran 'make dep' and 'make'. I copied all the static libraries *.a to my Eclipse project folder and added the libraries to the linker (-l).
But when I want to build I get the following error:
Invoking: Cross G++ Linker
arm-linux-gnueabihf-g++ -L"/home/david/workspace/VoIPBenchmark" -L/home/david/rpi/rootfs/usr/lib -L/home/david/rpi/rootfs/usr/lib/arm-linux-gnueabihf --sysroot=/home/david/rpi/rootfs/ -o "VoIPBenchmark" ./src/SipImplemantation.o ./src/SipImplementationPJ.o ./src/Timer.o ./main.o -lpjsua2-arm-unknown-linux-gnueabihf -lpjsua-arm-unknown-linux-gnueabihf -lpjsip-ua-arm-unknown-linux-gnueabihf -lpjsip-simple-arm-unknown-linux-gnueabihf -lpjsip-arm-unknown-linux-gnueabihf -lpjsdp-arm-unknown-linux-gnueabihf -lpjmedia-audiodev-arm-unknown-linux-gnueabihf -lportaudio-arm-unknown-linux-gnueabihf -lpjmedia-codec-arm-unknown-linux-gnueabihf -lpjmedia-arm-unknown-linux-gnueabihf -lspeex-arm-unknown-linux-gnueabihf -lgsmcodec-arm-unknown-linux-gnueabihf -lsrtp-arm-unknown-linux-gnueabihf -lilbccodec-arm-unknown-linux-gnueabihf -lresample-arm-unknown-linux-gnueabihf -lpjnath-arm-unknown-linux-gnueabihf -lpjlib-util-arm-unknown-linux-gnueabihf -lpj-arm-unknown-linux-gnueabihf -lpthread -lm -lrt -lasound -llinphone
/home/david/rpi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/../lib/gcc/arm-linux-gnueabihf/4.8.3/../../../../arm-linux-gnueabihf/bin/ld: /home/david/workspace/VoIPBenchmark/libsrtp-arm-unknown-linux-gnueabihf.a(ctr_prng.o)(.text+0x8c): unresolvable R_ARM_ABS32 relocation against symbol `ctr_prng'
/home/david/rpi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/../lib/gcc/arm-linux-gnueabihf/4.8.3/../../../../arm-linux-gnueabihf/bin/ld: final link failed: Nonrepresentable section on output
collect2: error: ld returned 1 exit status
make: *** [VoIPBenchmark] Error 1
I googled some and tried to add -fPIC in the ./configure step above, recopied the libraries, but without result. Does anyone know what this message is saying me, and better yet, knows a solution?
This problem has been resolved. I was using a library that also linked to the srtp library, this evidently conflicted. So I am now not using the library that causes the problem.
I'm trying to compile my application to link to a static library (.a file)
The command I use to build is this:
gcc -DUNIX -maix32 -o Release/bin/testApp Release/obj/main.o -ltestLib
When I build I get the following errors:
ld: 0711-317 ERROR: Undefined symbol: .test
ld: 0711-345 Use the -bloadmap or -bnoquiet option to obtain more information.
Where test is a method in libtestLib.a
Also if I try and build with a dynamic lib then it is successful.
gcc -DUNIX -maix32 -o Release/bin/testApp Release/obj/main.o libtestLib.so
Can you see where I am going wrong?
Can you try specifying a path to the archive file, rather than -ltestLib?
gcc -DUNIX -maix32 /path/to/testLib.a -o Release/bin/testApp Release/obj/main.o
I got a problem of linking an OpenSSL library into an existing project.
Where I do get it wrong?
Below are the steps I have followed.
I have downloaded the SSL library, configured and installed it. It gets installed in /usr/local/ssl.
2) I have copied libcrypto.a and libssl.a from /usr/local/ssl/lib into my project, something like /mnt/linux/bla/bla/lib.
3) Then I edit the make file and added path of libssl libcrpto there. The path added is one that is in project like /mnt/linux/bla /bla
3) make
4) build project via slick edit
When it builds I get a long error chain, like
../lib/libssl.a(t1_enc.o) :In function 't1sl_steup_key_block: undefined ref
Now, I guess copying .a files into project could be problem. Is there is any alternative for that or should I use ln -s to link .a files form /usr/local/openssl/lib into my project library folder? Below is the error.
Debug/FC5/m2pa.o -ldl -lpthread -ltdapi ../septel/gctlib.lib ../lib/libpq.a ../asn1/lib/libasn1per.a ../mysql/lib/libmysqlclient.a -L../lib ../asn1/lib/libasn1rt.a -lm -lcrypt -lcrypto -lssl -rdynamic
../lib/libssl.a(ssl_lib.o): In function `SSL_set_quiet_shutdown':ssl_lib.c:(.text+0x670): multiple definition of `SSL_set_quiet_shutdown'
../mysql/lib/libmysqlclient.a(ssl.o):ssl.cpp:(.text+0x125c): first defined here
/usr/bin/ld: Warning: size of symbol `SSL_set_quiet_shutdown' changed from 45 in ../mysql/lib/libmysqlclient.a(ssl.o) to 12 in ../lib/libssl.a(ssl_lib.o)
../lib/libssl.a(ssl_lib.o): In function `SSL_get_quiet_shutdown':ssl_lib.c:(.text+0x680): multiple definition of `SSL_get_quiet_shutdown'
../mysql/lib/libmysqlclient.a(ssl.o):ssl.cpp:(.text+0x12down' changed from 35 in ../mysql/lib/libmysqlclient.a(ssl.o) to 8 in ../lib/libssl.a(ssl_lib.o)
../lib/libssl.a(ssl_err2.o): In function `SSL_load_error_strings':ssl_err2.c:(.text+0x4): undefined reference to `ERR_load_crypto_strings'
../lib/libssl.a(ssl_algs.o): In function `SSL_library_init':ssl_algs.c:(.text+0x4): undefined reference to `EVP_des_cbc'
:ssl_algs.c:(.text+0xc): undefined reference to `EVP_add_cipher'
:ssl_algs.c:(.text+0x11): undefined reference to `EVP_des_ede3_cbc'
:ssl_algs.c:(.text+0x19): undefined reference to `EVP_add_cipher'
:ssl_algs.c:(.text+0x1e): undefined reference to `EVP_idea_cbc'
Have you tried using the libssl and libcrypto already installed in your /usr/lib directory (assuming you've installed the dev packages for both)? Once that compiles and runs without error using the default install, you can build your new libssl/libcrypto(?) from source, install to usr/local, and rebuild using the usr/local versions of the libraries.
You need to add the flag -lssl and -lcrypto in your makefile'
For example:
gcc somefile.c -o someprogram -lssl -lcrypto