Linker errors when using LLVM - c++

I'm trying to use LLVM to build a compiler backend, but I've gotten mired in linker errors. Currently all I attempt to do is include LLVMContext.h (I'm doing the IBM tutorial), but this gives me the following linker error:
$ g++ -o compiler *.o -L/home/jakob/llvm2/lib/*.a -lantlr4-runtime
BayesBaseListener.o:(.data.rel+0x0): undefined reference to `llvm::DisableABIBreakingChecks'
collect2: error: ld returned 1 exit status
Makefile:2: recipe for target 'compiler' failed
make: *** [compiler] Error 1
Any idea how to configure LLVM correctly so this doesn't happen?

The option -L is to add a path that the linker uses to search for libraries. The option -l (lower-case L) is to tell the linker to link with a specific library.
For your case though, if you want to link with all static libraries in a specific location, just list the library files as input files:
g++ -o compiler *.o /home/jakob/llvm2/lib/*.a -lantlr4-runtime
Note that I don't use the -L option.

Related

SDL2_Gfx - Linker issue with cygwin

I'm struggling to compile SDL_Gfx with cygwin.
The configure script worked without issues.
Here's the last makefile command:
/bin/sh ./libtool --tag=CC --mode=link gcc -g -O2 -I/usr/local/include/SDL2 -Dmain=SDL_main -no-undefined -release 1.0 -version-info 0:1:0 -o libSDL2_gfx.la -rpath /usr/local/lib SDL2_framerate.lo SDL2_gfxPrimitives.lo SDL2_imageFilter.lo SDL2_rotozoom.lo -L/usr/lib -lcygwin -lSDL2main -lSDL2
libtool: link: warning: library `/usr/lib/libSDL2.la' was moved.
And here's the linker "warning" message.
*** Warning: linker path does not have real file for library -lSDL2main.
*** I have the capability to make that library automatically link in when
*** you link to this library. But I can only do this if you have a
*** shared version of the library, which you do not appear to have
*** because I did check the linker path looking for a file starting
*** with libSDL2main and none of the candidates passed a file format test
*** using a file magic. Last file checked: /lib/libSDL2main.a
If i try to ignore this, I'm getting this error when I try to use the library inside my application:
In function `pixel':
/usr/local/lib/SDL2_gfx-1.0.1/SDL2_gfxPrimitives.c:75: undefined reference to `SDL_RenderDrawPoint'
/usr/local/lib/SDL2_gfx-1.0.1/SDL2_gfxPrimitives.c:75:(.text+0x11): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `SDL_RenderDrawPoint'
UPDATE: I tried to switch compiler to use mingw64 instead of cywin. I'm having a similar issue, I think this is related to libtool since I can compile an external programs with similar c/l flags without issues.
I don't know what I can try I ran out of ideas, please help.
Thank you

Linker error while compiling code in Windows

I am trying to compile my C++ code in Windows cmd.
I have implemented UnitTest++ in the project. When I run:
g++ main.cpp -IC:\Test\TreeObjModel\include -IC:\Test\unittest-cpp-master\UnitTest++
it gives the following error:
undefined reference to `UnitTest::RunAllTests()' collect2.exe: error:
ld returned 1 exit status
Can anyone help me to resolve this? Is any more info needed?
You probably are missing to compile some other cpp file (UnitTest.cpp?); or maybe you must link to some UnitTest library, where the code for UnitTest::RunAllTests() resides.
The command line option for linking a library with GCC is -l library_name.

Linker Error using g++ with Qt 4.5.1

I'm trying to test out a new dev environment and I am having some problems referencing some of the required Qt libraries.
First I ran this:
$ g++ HelloWorld.C -o HelloWorld -I /usr/local/Trolltech/Qt-4.5.1/include/QtCore/ -I /usr/local/Trolltech/Qt-4.5.1/include/
and got this error:
/tmp/ccmsm4kZ.o: In function `QString::QString(char const*)':
HelloWorld.C:(.text._ZN7QStringC2EPKc[_ZN7QStringC5EPKc]+0x1d): undefined reference to `QString::fromAscii_helper(char const*, int)'
/tmp/ccmsm4kZ.o: In function `QString::~QString()':
HelloWorld.C:(.text._ZN7QStringD2Ev[_ZN7QStringD5Ev]+0x2d): undefined reference to `QString::free(QString::Data*)'
collect2: ld returned 1 exit status
So then I added reference to the QtCore library via:
$ g++ HelloWorld.C -o HelloWorld -I /usr/local/Trolltech/Qt-4.5.1/include/QtCore/ -I /usr/local/Trolltech/Qt-4.5.1/include/ -L /usr/local/Trolltech/Qt-4.5.1/lib -lQtCore
which removed the compile errors, however when I try to run the program I get this error:
./HelloWorld: error while loading shared libraries: libQtCore.so.4: cannot open shared object file: No such file or directory
I wasn't able to find a solution for this problem via google. Anyone have advice?
That error indicates that while the linker can find the library at compilation, it can't find it during runtime.
You should update your LD_LIBRARY_PATH to include that location like this:
In ~.bashrc probably somewhere near the bottom:
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/Trolltech/Qt-4.5.1/lib
Alternatively, if you want to make this persistent throughout your system (and have root access), you can make an entry in /etc/ld.so.conf.d (on RedHat, I'm not sure about the other distributions)
touch /etc/ld.so.conf.d/qt.conf
Add the path to this file, and then update your runtime via /sbin/ldconfig

Linkage fails, what's going on?

I'm trying to build a specific program on Ubuntu 12.04 64 bit.
The program needs to be compiled 32 bits.
I installed the ia32-libs and gcc-multilib packages.
I managed to compile it on 3 different computers, but on this one, it fails with a weird error.
for some reason, libm.so is not picked up correctly, or something is wrong with the library.
This is the actual compilation line that fails as it was extracted from the Makefile.
gcc -o x86_32_obj/foo x86_32_obj/foomain.o -m32 -fPIC -fno-stack-protector -lc -lgcc -lm -lpthread -lrt -lstdc++ ../libfoo/lib/./libfii.x86_32.a
This is the output
/usr/bin/ld: ../libfoo/lib/./libfoo.x86_32.a(NK_Meas.o): undefined reference to symbol 'expf##GLIBC_2.0'
/usr/bin/ld: note: 'expf##GLIBC_2.0' is defined in DSO /usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../lib32/libm.so so try adding it to the linker command line
/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../lib32/libm.so: could not read symbols: Invalid operation
collect2: ld returned 1 exit status
make[1]: *** [foo] Error 2
make: *** [foo] Error 2
I have seen errors such as this in relation to the linking order. It may be possible to address the error by placing the libm linking directive at the very end of your linking configuration.
These interdependencies are very much system dependent, which is probably why the same command works on other systems.
Found the problem.
Apparently, the library file I was linking against was compiled using a different version of GCC.
I don't know how exactly it's related, but once I replaced the gcc compiler to the one used with the library it worked.

/usr/bin/ld: cannot find -llibeststring.a

I am using festival TTS c++ API in my program.I have downloaded all files from http://www.cstr.ed.ac.uk/downloads/festival/2.0.95/
and install festival and speech_tools successfully on my UBUNTU 10.04
now when compile my c++ programme gcc gives error:
g++ -L/usr/lib -L/home/peeyush/Desktop/festival/src/lib -L/home/peeyush/Desktop/speech_tools/lib -o"peeyush" ./src/peeyush.o -llibeststring.a -llibestbase.a -llibestools.a -llibFestival.a
/usr/bin/ld: cannot find -llibeststring.a
collect2: ld returned 1 exit status
make: *** [peeyush] Error 1
so please help me to sort out this error.
-Thanks
Peeyush Chandel(INDIA)
When using the -l option, you don't specify the leading lib or trailing .a or .so parts of the name as they're assumed by the linker. You would want to use something like -leststring to pick it up (assuming that your -L path is set correctly.
Alternately you can specify the exact filename (so no -l, just libeststring.a) as part of the object list to link (make sure the order is right relative to your .o files), but I believe in that case you would have to specify the path as the linker won't know to search your -L path. Easiest is to use -l though.