as a project of my own, I'm writing a refactoring library (so it can by used by other applications) using libclang for code analysis.
The problem is when i try to compile my program to a static library everything is okey, but when i try to link my library (using some clang code) with some demo application (just main function calling my code) the linker is reporting:
./librefactor.a(renamer.o):(.data.rel.ro+0x60): undefined reference to 'clang::ASTConsumer::HandleInterestingDecl(clang::DeclGroupRef)'
./librefactor.a(renamer.o):(.data.rel.ro+0x80): undefined reference to `clang::ASTConsumer::HandleTopLevelDeclInObjCContainer(clang::DeclGroupRef)'
./librefactor.a(renamer.o):(.data.rel.ro+0x88): undefined reference to `clang::ASTConsumer::HandleImplicitImportDecl(clang::ImportDecl*)'
collect2: error: ld returned 1 exit status
Here is a makefile I build my library with: library makefile
Here is a makefile I build an example with: library example
I commented out some parts of the code to make the error as short as possible but they are some similiar errors (undefined reference) from other part of clang i use in my project.
Problem is I don't understand why linker can't find definitions of these functions/methods. They are not pure virtual in base class so I don't need to defined them. As I see it the linker is trying to find the definition of these in my part of the code istead in clang binaries. Could somebody please explain me where I'm wrong here and explain/repair it?
Related
I'm building a golang project by using Go1.12 + msys2/mingw-w64(9.2.0), it shows errors:
D:\Go\pkg\tool\windows_amd64\link.exe: running gcc failed: exit status 1
D:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib/../lib/crt2.o: in function `pre_c_init':
E:/mingwbuild/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/crtexe.c:146: undefined reference to `__p__fmode'
D:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib/../lib/crt2.o: in function `__tmainCRTStartup':
E:/mingwbuild/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/crtexe.c:290: undefined reference to `_set_invalid_parameter_handler'
D:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: E:/mingwbuild/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/crtexe.c:299: undefined reference to `__p__acmdln'
D:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64_libmingw32_a-merr.o): in function `_matherr':
E:/mingwbuild/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/merr.c:46: undefined reference to `__acrt_iob_func'
D:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64_libmingw32_a-pseudo-reloc.o): in function `__report_error':
E:/mingwbuild/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/pseudo-reloc.c:149: undefined reference to `__acrt_iob_func'
D:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: E:/mingwbuild/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/pseudo-reloc.c:150: undefined reference to `__acrt_iob_func'
collect2.exe: error: ld returned 1 exit status
After some research I'm sure it's a msvcrt compatibility issue of mingw64.
I know there are workarounds like this: unresolved external symbol __imp__fprintf and __imp____iob_func, SDL2
But it doesn't solve all of my issues.
I try to link the library: LDFLAGS: -L%filepath% -llegacy_stdio_definitions, nothing changes.
Is there a patch to fix it, or do I have to build my custom version of mingw64?
So I answer my question by myself, the case is closed.
Yes, Mingw64 uses msvcrt.
Here are some tips that could help to solve dependency problems between Mingw64 & msvcrt.
The major goal is to let compiler load the correct version of MSVCRT library family.
1.Update Mingw64.
2.Check out MSVCRT_VERSION in Mingw64\include_mingw.h(or x86_64-w64-mingw32\include), make sure the version number matches your windows version, or modify it.
3.Take a look at linker option like "#cgo LDFLAGS: -Lxxx", don't mess the library path. Remove any unnecessary library path setting, let linker finds libraries itself.
Make sure everything is built with same libraries.
I have a C++ app where I use some C functions. I have declared those C functions inside extern "C" {}; And it is compiling and working just fine.
I am using 'gcc' for compiling the C code, and using 'g++' for linking that object with C++ object.
GCOV fails by throwing me the following error:
hidden symbol `__gcov_init' in /usr/lib/gcc/x86_64-linux-gnu/5/libgcov.a(_gcov.o) is referenced by DSO
/usr/bin/ld: final link failed: Bad value
collect2: error: ld returned 1 exit status
I have no idea as this is new to me combining C and C++ code. Any one have idea why "gcov" failing with linking stage. If I disable those "C" functions in my app then it "gcov" is not giving me that error.
C Functions I am using just initialising a struct which has function pointers in it with some functions.
Any help is really appreciated.
Thanks
I was able to fix it by adding "-lgcov" flag while linking, but I don't know why it did not work even though "--coverage" flag should do the linking for this. Only have this problem when linking C object file with C++ object.
Here is the link for the answer: link
My problem is rather specific, but bear with me.
This in the end is kinda reverse engineering, but this problem in particular seems to fit more this board.
So, I have a shared object compiled for MIPS written in C++. I don't have the source code of the lib. The lib is compiled using GCC 4.3.3. I want to use functions present in this shared object in my amd64 computer running elementary OS. To do this, I used the sourcery cross compiler to cross compile some C++ code to MIPS, that would use this object.
So far I managed this except for this one compile error, which I cannot figure out. The lib is called libdvl.so, and uses as dependency libc.so.0 (and both are in the same folder as the cpp code).
mips-linux-gnu-g++ -g -L/path/to/lib -Wl,-rpath,/path/to/lib -o verifier verifier.cpp -ldvl
which gives me
(...)/mgc/embedded/codebench/bin/../lib/gcc/mips-linux-gnu/4.9.1/../../../../mips-linux-gnu/bin/ld: warning: libc.so.0, needed by /path/to/lib/libdvl.so, may conflict with libc.so.6
(...)/mgc/embedded/codebench/bin/../lib/gcc/mips-linux-gnu/4.9.1/../../../../mips-linux-gnu/bin/ld: errno##GLIBC_PRIVATE: TLS definition in (...)/mgc/embedded/codebench/bin/../mips-linux-gnu/libc/lib/libc.so.6 section .tbss mismatches non-TLS definition in /path/to/lib/libc.so.0 section .bss
/path/to/lib/libc.so.0: error adding symbols: Bad value
collect2: error: ld returned 1 exit status
So I added "-l:libc.so.0" and got this
(...)/mgc/embedded/codebench/bin/../lib/gcc/mips-linux-gnu/4.9.1/../../../../mips-linux-gnu/bin/ld: errno: TLS definition in (...)/mgc/embedded/codebench/bin/../mips-linux-gnu/libc/lib/libc.so.6 section .tbss mismatches non-TLS definition in libc.so.0 section .bss
(...)/mgc/embedded/codebench/bin/../mips-linux-gnu/libc/lib/libc.so.6: error adding symbols: Bad value
collect2: error: ld returned 1 exit status
Any idea how to solve this? I know I am using GCC 4.9.1, but I already downloaded the older code sourcery version which uses GCC 4.3.154 and got the exact same error.
EDIT 1: Exactly as Lol4t0 said, filtered using c++filt it gives an actual function name from stdc++. Using
mips-linux-gnu-g++ -g -L/path/to/lib -Wl,-rpath,/path/to/lib -I/path/to/lib -o verifier verifier.cpp -ldvl -l:libuClibc++.so.0 -l:libutil.so.0 -l:libc.so.0 -l:ld-uClibc.so.0 -nodefaultlibs
to give to libdvl its depencies (as I will not rewrite stdc++ :p), I get the following compile error:
(...)/mgc/embedded/codebench/bin/../lib/gcc/mips-linux-gnu/4.9.1/../../../../mips-linux-gnu/bin/ld: /tmp/cc66DLda.o: undefined reference to symbol '_Unwind_Resume##GCC_3.0'
(...)/mgc/embedded/codebench/bin/../mips-linux-gnu/libc/lib/libgcc_s.so.1: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
I already confirmed lib dependencies and the order in which they appear.
Any thoughts on this?
Thanks for all the help.
Using -nodefaultlibs solves the first problem though.
You are linking against GLIBC (libc.so.6) and some other libc (libc.so.0).
That could never work: you have to have everything compiled and linked against a single, consistent libc.
Since your libdvl.so uses as dependency libc.so.0, and assuming you can't rebuild libdvl.so, you have to use crosscompiler that targets libc.so.0 (which is possibly dietlibc, or uClibc), and compile and link everything else using that toolchain. Your crosscompiler on the other hand appears to target GLIBC, and will not do you any good.
After a lot of trial and error, you may be able to link the final binary using inconsistent builds, and your binary may even get to main (that is very unlikely). But chances of such binary actually working correctly are minuscule.
Recently I found an example of how to use the expect library in C++. I tried to compile it, but the compiler (g++) said, that tcl8.5/expect.h doesn't exists. So I tried to include tcl8.6/expect.h - still the same error. I checked the /usr/include/ directory and I wasn't surprised when I've noticed, that there is no tcl8.x directory.
I've searched for files with "expect" in their name. Here's what I found:
/usr/include/expect_tcl.h
/usr/include/expect_comm.h
/usr/include/expect.h
Unfortunately when I tried to include any of these I got the following list of errors during compilation:
> g++ test.cpp -Wall -std=c++0x -ltcl8.6 -lglog -o test
/tmp/cce8k1BA.o: In function `task(std::string const&, std::string const&, std::string const&)':
test.cpp:(.text+0x16): undefined reference to `exp_is_debugging'
test.cpp:(.text+0x20): undefined reference to `exp_timeout'
test.cpp:(.text+0x38): undefined reference to `exp_popen'
etc...
How can I solve this problem?
[EDIT]
When I tried to link it with the expect lib (-lexpect) I got the following error:
/usr/bin/ld: cannot find -lexpect
collect2: error: ld returned 1 exit status
I'm sure that both - tcl8.6 and expect 5.45-4 are installed.
The usual way of distributing Expect these days puts the shared library in a non-standard location and loads it dynamically by full pathname. This works well and is minimal fuss for most people, but does make it rather hard to use Expect's C interface in your own code.
The easiest way is going to be to build your own copy from source, especially as that will give you control over how exactly it was built. This can particularly include keeping the majority of symbols in the library instead of stripping them on install, which will help a lot with debugging. You probably ought to use the current supported version. (Yes, it's a release from several years ago. It doesn't need a lot of support effort most of the time.)
You haven't linked to the expect library during your build. Add -lexpect to your g++ command.
im trying to compile a simple Ogre3d application using OIS; i override the function like so:
virtual bool keyPressed(const OIS::KeyEvent& arg);
However, i get linker errors like this:
CMakeFiles/thorium.dir/Application/Application.cpp.o:(.rodata._ZTVN7Thorium11ApplicationE[_ZTVN7Thorium11ApplicationE]+0x48): undefined reference to `Thorium::Application::keyPressed(OIS::KeyEvent const&)'
Ive added the library to my cmake as well as tried using a shared library but it also did not work. Im using the ois package and therefore havent compiled myself.
target_link_libraries(... OgreMain OIS.a)
Undefined reference error often occures when the library code not loaded.
Put libNAME.a file in lib searching path and compile modules with key
-lNAME