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c++linkermingwasmjit

How can I use the library that I have built without error from source, but not compiling for my own project?


I'd like to try the AsmJit library. Building it with 'cmake' and 'make' from source was no problem, the examples it provided were all compiled and executed perfectly. I also did make install to export the dependency files.

I then wanted to compile my own program using this library, so I retrieved the generated files (the headers and the static lib) to add them to a new project whose the code is a copy/paste of the first example given on the library's website:

// #define ASMJIT_NO_DEPRECATED // this line is no part of the original code
#include <asmjit/asmjit.h>
#include <stdio.h>

using namespace asmjit;

// Signature of the generated function.
typedef int (*Func)(void);

int main(int argc, char* argv[]) {
  JitRuntime rt;                          // Runtime designed for JIT code execution.

  CodeHolder code;                        // Holds code and relocation information.
  code.init(rt.environment());            // Initialize CodeHolder to match JIT environment.

  x86::Assembler a(&code);                // Create and attach x86::Assembler to `code`.
  a.mov(x86::eax, 1);                     // Move one to 'eax' register.
  a.ret();                                // Return from function.
  // ----> x86::Assembler is no longer needed from here and can be destroyed <----

  Func fn;
  Error err = rt.add(&fn, &code);         // Add the generated code to the runtime.
  if (err) return 1;                      // Handle a possible error returned by AsmJit.
  // ----> CodeHolder is no longer needed from here and can be destroyed <----

  int result = fn();                      // Execute the generated code.
  printf("%d\n", result);                 // Print the resulting "1".

  // All classes use RAII, all resources will be released before `main()` returns,
  // the generated function can be, however, released explicitly if you intend to
  // reuse or keep the runtime alive, which you should in a production-ready code.
  rt.release(fn);

  return 0;
}

This is what the hierarchy of my test project looks like:

include\
    asmjit\    // The generated headers from the library build
libasmjit.a    // The generated static library from the library build
main.cpp       // My program's code, as pasted above

And here is the command line used to compile:

g++ main.cpp -o main -Iinclude -L -lasmjit

A first compilation error occurs:

In file included from include/asmjit/./core.h:2008,
                 from include/asmjit/asmjit.h:27,
                 from main.cpp:1:
include/asmjit/././core/builder.h:375:20: error: function 'asmjit::Error asmjit::BaseBuilder::dump(asmjit::String&, uint32_t) const' definition is marked dllimport
  375 |   ASMJIT_API Error dump(String& sb, uint32_t formatFlags = 0) const noexcept {
      |                    ^~~~

After some research in the lib code, defining the ASMJIT_NO_DEPRECATED macro (see in the code above, the first commented line) prevents this error from being reproduced. I doubt this is a good idea, as it may be the cause of the following next link errors:

C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x35): undefined reference to `__imp__ZN6asmjit10JitRuntimeC1EPKNS_12JitAllocator12CreateParamsE'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x45): undefined reference to `__imp__ZN6asmjit10CodeHolderC1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x6e): undefined reference to `__imp__ZN6asmjit10CodeHolder4initERKNS_11EnvironmentEy'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x82): undefined reference to `__imp__ZN6asmjit3x869AssemblerC1EPNS_10CodeHolderE'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x11f): undefined reference to `__imp__ZN6asmjit3x869AssemblerD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x12f): undefined reference to `__imp__ZN6asmjit10CodeHolderD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x142): undefined reference to `__imp__ZN6asmjit10JitRuntimeD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x159): undefined reference to `__imp__ZN6asmjit3x869AssemblerD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x169): undefined reference to `__imp__ZN6asmjit10CodeHolderD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x17c): undefined reference to `__imp__ZN6asmjit10JitRuntimeD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text$_ZN6asmjit11BaseEmitter4emitIJRKNS_3x862GpEiEEEjjDpOT_[_ZN6asmjit11BaseEmitter4emitIJRKNS_3x862GpEiEEEjjDpOT_]+0x4c): undefined reference to `__imp__ZN6asmjit11BaseEmitter6_emitIEjRKNS_8Operand_ES3_'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text$_ZN6asmjit11BaseEmitter4emitIJEEEjjDpOT_[_ZN6asmjit11BaseEmitter4emitIJEEEjjDpOT_]+0x1b): undefined reference to `__imp__ZN6asmjit11BaseEmitter6_emitIEj'
collect2.exe: error: ld returned 1 exit status

I couldn't find a way to prevent the first error from occurring, except by defining this macro, and I also don't understand why the link editor can't find the references. I have also tried placing these dependencies (headers + static lib) in the appropriate MinGW directories (i.e. the global include and lib directories), but this does not change anything.

How do I compile this program, which is quite simple? I would also like to know why what I did didn't work, knowing the cause of this mistake, I will probably be able to deal with others of the same style in the future.

PS: I don't have much experience with managing external dependencies in C and C++. I am under Windows, using MinGW and the last version of GCC.


Solution

  • You are missing ASMJIT_STATIC compile-time definition - it has to be defined if you use AsmJit statically. This definition is checked at compile time by AsmJit to setup ASMJIT_API macro, which expands to a compiler-specific import/export/visibility attribute.

    AsmJit documentation (Build Instructions section) says [1]:

    Projects that use AsmJit statically must define ASMJIT_STATIC in all compilation units that use AsmJit, otherwise AsmJit would use dynamic library imports in ASMJIT_API decorator. The recommendation is to define this macro across the whole project that uses AsmJit this way.

    So in your particular case this should fix the problem:

    g++ main.cpp -o main -Iinclude -L. -lasmjit -DASMJIT_STATIC
    

    NOTE: The documentation link purposely links to the index page so it won't be a dead link once the documentation is reorganized.

    [1] https://asmjit.com/doc/index.html