I need to link to the .so files and headers found in /root/lib and /root/include in a project in xcode 3.2.6. ROOT is an analysis framework from CERN.
There is a utility root-config, that will return all the libraries necessary, I can compile on the command line using:
CFLAGS = `root-config --cflags`
GLIBS = `root-config --glibs`
test : main.cpp main.h
g++ $(CFLAGS) $(GLIBS) -g -Wall main.cpp -02 -o test
Program runs fine with no bugs. But, I want to use xcode for the whole project, but can't get it to either
A: use this utility
or
B: search the right paths to the .so files. I have included /root/lib and /root/include in the build variables header_search_paths and library_search_paths under the build settings. I then actually type in the files I need into the other_linker_flags like so:
-llibTree -llibHist -llibRIO -llibCint -llibCore
xcode returns the message:
ld: library not found for -llibTree
collect2: ld returned 1 exit status
Command /Developer/usr/bin/g++-4.2 failed with exit code 1
Does anybody know whats going on? Can xCode compile .so files? Is there some other issue here?
This has nothing to do with ROOT. To link against a library named libSomething.so in your library search path you can use a linker flag -lSomething. You want to link against e.g. libTree.so, so the correct flag to use would be -lTree, not -llibTree which would look for liblibTree.
Related
I've recently started coding with c++ and the project that im currently on requires imgui. so i set up the .h and .cpp libraries in a folder called "include" in the same folder as the source code. I'm currently trying to run the cpp in https://github.com/ocornut/imgui/tree/master/examples/example_glfw_opengl3 and compile it with gcc using gcc imgui.cpp -lstdc++ -lglfw -lGL -limgui but i just get
/usr/bin/ld: cannot find -limgui
collect2: error: ld returned 1 exit status
yes i know there is a make file in the link but im using the file in another folder.
Assuming you downloaded imgui to a place called $IMGUI_DIR and the file that contains your main function is main.cpp, your compile commandline should look like the following: (the \ are just there to break up the command)
g++ main.cpp -o main \
$IMGUI_DIR/imgui*.cpp $IMGUI_DIR/backends/imgui_impl_glfw.cpp $IMGUI_DIR/backends/imgui_impl_opengl3.cpp \
-I $IMGUI_DIR -I $IMGUI_DIR/backends \
-lglfw -lGL
In order, you tell the compiler:
Where your code is and where to put the output
What Imgui code to include, namely the core library and the two backends you want to use
Where Imgui code should look for its headers
If all this sounds like a lot, know that you can simply build the example you linked and override IMGUI_DIR at compile time with make IMGUI_DIR=/path/to/imgui
I use MinGW32 more specifically TDM-GCC-32. I have very simple project I link to one custom library but this error pops out:
>g++ -D_WIN32 -D_MINGW -lgdi32 -lgdiplus -Linterception/x86 -linterception main.cpp -o interceptor.exe
interception/x86/libinterception.a(dgnes00125.o):(.text+0x0): multiple definitio
n of `atexit'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x2c0):
first defined here
interception/x86/libinterception.a(dgnes00109.o):(.text+0x0): multiple definitio
n of `_onexit'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x2d0):
first defined here
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../../mingw32/bin/ld.exe: C:/TD
M-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o: bad reloc address 0x20 in
section `.eh_frame'
collect2.exe: error: ld returned 1 exit status
Commands I use to build the library:
gcc -DINTERCEPTION_EXPORT -D_WIN32 -D_MINGW -shared -o interception.dll interception.c
dlltool -z interception.def --export-all-symbol interception.dll
dlltool -d interception.def -l libinterception.a
I guess I have to use different options for compiling the library to avoid redefinitions..
The dlltool method I believe is currently deprecated. I can't fault you here though, as most of the available documentation still says to do it this way.
Gcc will link directly against .dll files, making .a files obsolete (at least for dealing with dll's - the only current reason to use a .a file is for static linking). You don't even have to specify the dll with the -l flag, although you have to specify the path of the dll if it's not in your current directory
C:\Users\burito>gcc main.o opengl32.dll -o main.exe
gcc: error: opengl32.dll: No such file or directory
C:\Users\burito>gcc main.o c:\Windows\system32\opengl32.dll -o main.exe
C:\Users\burito>
Ok, opengl32.dll is perhaps not a great example, but I hope I've given you the general idea.
I believe MSVC still needs its .lib files to use a .dll, for which there are several ways of making them if the library doesn't come with one.
In your specific case, the command that should work would be...
g++ -D_WIN32 -D_MINGW -lgdi32 -lgdiplus interception/x86/interception.dll main.cpp -o interceptor.exe
If for whatever reason you really do need to create a .a file from a .dll, the command that has worked for me is...
gendef interception.dll
dlltool -l interception.a -d interception.def -k -A
As the repository you linked does provide .dll files in its releases, you shouldn't have to build them yourself
I have downloaded and build the boost libraries with
bootstrap mingw
and
b2 toolset=gcc
and the libraries are created in
C:\Boost\boost_1_57_0\stage\lib
In eclipse I have added this directory as a library path
and added the library libboost_thread-mgw49-mt-1_57 with and without the .a on the end.
the g++ line looks like
g++ "-LC:\\Boost\\boost_1_57_0\\stage\\lib" -o MyThread.exe main.o MyThread.o -llibboost_thread-mgw49-mt-1_57
and I get the error message
ld.exe: cannot find -llibboost_thread-mgw49-mt-1_57 collect2.exe: error: ld returned 1 exit status
If I add the .a it is appended to the error message as expected.
what am I doing wrong?
Specify the library without the lib prefix (which is the UNIX convention):
g++ "-LC:\Boost\boost_1_57_0\stage\lib" -pthread -o MyThread.exe main.o MyThread.o -libboost_thread-mgw49-mt-1_57
There's even a chance that (with the help of some standard convention symlinks) you could just say -lboost_thread.
PS Don't forget to use -pthread as well
I am using Ubuntu and my IDE is Aptana 3.0
I am getting the following error when trying to build. The library libfcgi.a is located in /usr/local/lib/.
In the Library C++ Linker section of the project properties, I added /usr/local/lib/ to the search path and the file /usr/local/lib/libfcgi.a.
Why can I still not build?
**** Build of configuration Debug for project rtb ****
make all
Building target: rtb
Invoking: GCC C++ Linker
g++ -L/usr/local/lib -o"rtb" ./src/rtb.o -l/usr/local/lib/libfcgi.a
/usr/bin/ld: cannot find -l/usr/local/lib/libfcgi.a
collect2: ld returned 1 exit status
make: *** [rtb] Error 1
I think this may be what you want;
g++ -L/usr/local/lib -o "rtb" ./src/rtb.o -lfcgi
-l<value> will automatically look in all folders listed with -L for a library named lib<value>.a or lib<value>.so, all you need is the '-lfcgi'.
Try "-lfcgi" instead
g++ -L/usr/local/lib -o"rtb" ./src/rtb.o -lfcgi
Your linker flag is wrong it needs to be -lfcgi and not the whole path with the "lib" prefix and the .a suffix.
You can change it by hand, or in Apatana. To do so you don't have to give him the full qualified path to your lib two times. ( You already gave him the search path, remember? ). Usually you define additional libraries just like this:
cfgi and your IDE does the rest to add it to the linker flags!
You should do
g++ -o "rtb" ./src/rtb.o -lfcgi
In the unlikely case that /usr/local/lib/ is not in your search path, you can either add that path in the command line like
g++ -L/usr/local/lib -o "rtb" ./src/rtb.o -lfcgi
or put it in the environment variable LIBRARY_PATH before calling your compile command, e.g. with bash:
if [ -z "$LIBRARY_PATH" ];
then export LIBRARY_PATH=/usr/local/lib;
else export LIBRARY_PATH="$LIBRARY_PATH":/usr/local/lib;
fi
If you insist in giving the explicit file name, omit the -l:
g++ -L/usr/local/lib -o "rtb" ./src/rtb.o /usr/local/lib/libfcgi.a
However I'd advise against that because it's inflexible. If the issue is that there's another, incompatible version of the library installed, it's better to make sure that the correct one comes first in the search path (or even better, make sure that the wrong one isn't in the search path at all ― maybe even by removing it from the system).
That's for the help all....really appreciate it.
Here is the solution. I had to use -lfcgi++ and I added the
g++ -L/usr/local/include/ -lfcgi++ -o"rtb" ./src/rtb.o
The above was the output from aptanta console. I tried -lfcgi and did not work. Google search lead to using -lfcgi++.
On OSX 10.6.4 with i686-apple-darwin10-g++-4.2.1 compiling using TextMate and a Makefile which in the first place has been made für a Linux and I am trying to translate for OSX.
When compiling a c++ project I get the "can't link with a main executable" error:
g++ -Wall -g -I ~/svnX-Repository/axp-Projekte/xrlfupa/trunk/src/ -I ~/svnX-Repository/boost_1_44_0 -I /opt/local/var/macports/software/boost/1.44.0_0/opt/local/lib/ -I /opt/local/var/macports/software/gsl/1.14_0/opt/local/include/ -o xrfLibTest xrfLibTest.o excitFunctions.o xrfFunctions.o filterFunctions.o detectorFunctions.o -L/opt/local/var/macports/software/boost/1.44.0_0/opt/local/lib/ -L/opt/local/var/macports/software/gsl/1.14_0/opt/local/lib/ -lm -lxrlTUB -lboost_serialization -lgsl -lgslcblas # Debug 1
ld: in /usr/local/lib/libxrlTUB.so, can't link with a main executable
collect2: ld returned 1 exit status
make: *** [prog] Error 1
The library that is mentioned (libxrlTUB.so) is in its place (/usr/local/lib/libxrlTUB.so) but, possibly that is where the problem came from, the libxrlTUB.so has been compiled by myself beforehand as well.
The compile process went through, it was generated by swig, though there was a warning:
g++ -arch x86_64 -m32 -g -fpic -I /usr/include/python2.6 -c PyXrl_wrap.cxx
In function 'void SWIG_Python_AddErrorMsg(const char*)':
warning: format not a string literal and no format arguments
which, as far as I could find out, shouldnt be a problem. (Or is it?)
Unfortunately this whole thing is part of a project from the university. Actually I am supposed to write an X-ray-analysis script in python, which would be fine, if... well if I wouldn't be expected to use the librarys that are meant to result from this c++ project.
(Afterwards they should be used via import in python.)
I am not really experienced with c++, neither with compiling on OSX systems. So far I have been bothering with scipting (python, bash, etc). So Maybe I am just missing something simple. Hopefully someone can give me an hint where I can continue reading in order to deal with the above "can't link with a main executable" error...
Thanx in advance,
Liam
The error message is telling you the problem—it is that /usr/local/lib/libxrlTUB.so is not a shared library; it's an executable. You can't link against an executable. Probably whatever build process you used for libxrlTUB.so didn't understand how to build shared libraries on the Mac (it's more suspect because .dylib is the correct extension to use.)
Take a look at Apple's documentation on compiling dynamic libraries. You can use file to make sure your output is of the correct type, for example:
% gcc -c foo.c
% gcc -dynamiclib foo.o -o foo.dylib
% file foo.dylib
foo.dylib: Mach-O 64-bit dynamically linked shared library x86_64
Without -dynamiclib you end up with an executable, which may be the problem you've run into.