I found a simple assembly tutorial online that uses some C functions. I've already used NASM to generate a .obj file but I'm having trouble linking against the C library from the command line. How do I do this with link.exe?
I'm using Visual C++ 2010 Express.
Thanks for the help.
Specify one of the run-time library options: /MD (multithreaded DLL run-time) or /MT (multithreaded static run-time).
In debug builds, specify /MDd or /MTd respectively.
Related
When linking my final .exe file I receive error: C1047 The object or library file XX.lib was created by a different version of the compiler than other objects like YY.lib rebuild all objects and libraries with the same compiler.
According to the documentation: https://learn.microsoft.com/en-us/cpp/error-messages/compiler-errors-1/fatal-error-c1047?view=msvc-170
It happens when some object files are compiled with /GL or /LTCG flags.
YY.lib is an external library. It is C library, compiled with different version of Visual Studio. But it should be fine. It has no /GL nor /LTCG flag enabled.
XX.lib is another static library. I partially control how it is created. It contains many third-party libraries also inside.
Now I need to somehow figure out which .obj files inside XX.lib were compiled with /GL flag (to remove this flag and fix the issue). Is there any way to find out which .obj files were compiled with the /GL or /LTCG flag enabled without direct access to source/build systems of those libraries ? (I assume it should be possible as linker is able to determine it). But I can't find where this information is stored. I can unpack the static library to individual .obj files. But using e.g. dumpbin I don't see any info about /GL or /LTCG flag.
I am trying to build a c++/cuda extension with Pytorch following the tutorial here, (with instructions how to use pytorch with c++ here). My environment details are:
Using Microsoft Visual Studio 2019 version 16.6.5
Windows 10
libtorch c++ debug 1.70 with cuda 11.0 installed from the pytorch website
I am using this cmake code where I set the include directory for python 3.6 and the library for python36.lib
cmake_minimum_required (VERSION 3.8)
project ("DAConvolution")
find_package(Torch REQUIRED)
# Add source to this project's executable.
add_executable (DAConvolution "DAConvolution.cpp" "DAConvolution.h")
include_directories("C:/Users/James/Anaconda3/envs/masters/include")
target_link_libraries(DAConvolution "${TORCH_LIBRARIES}" "C:/Users/James/Anaconda3/envs/masters/libs/python36.lib")
if (MSVC)
file(GLOB TORCH_DLLS "${TORCH_INSTALL_PREFIX}/lib/*.dll")
add_custom_command(TARGET DAConvolution
POST_BUILD
COMMAND ${CMAKE_COMMAND} -E copy_if_different
${TORCH_DLLS}
$<TARGET_FILE_DIR:DAConvolution>)
endif (MSVC)
I set the CMake command arguments to be -DCMAKE_PREFIX_PATH=C:\libtorch (my path to libtorch debug mentioned above). I am building with the x64-debug option in MSVC version (as building with the x-64 Release option gives me a torch-NOTFOUND error).
The example DAConvolution.cpp file is:
#ifdef _DEBUG
#undef _DEBUG
#include <python.h>
#define _DEBUG
#else
#include <python.h>
#endif
#include <torch/extension.h>
Where I have undefined the _DEBUG flag so that the linker does not look for the python36_d.lib file (which I do not have).
I am getting a linking error:
Simply including torch.h works fine, but when I want to include the extension header thats when I get these problems, as it uses Pybind 11 I believe. Any insights much appreciated. I have tried to include all the info I can, but would be happy to give more information.
For Windows and with Visual studio, you are better to work with the Visual Studio rather than the CMake.
Just create a simple Console Application, go to the project's Properties, change the Configuration type to Dynamic Library (dll), Configure the include and Library directories, add the required enteries to your linker in Linker>Input (such as torch.lib, torch_cpu.lib, etc) and you are good to go click build, and if you have done everything correctly you'll get yourself a dll that you can use (e.g loading it using torch.classes.load_library from Python and use it.
The Python debug version is not shipped with Anaconda/ normal python distribution, but if you install the Microsoft Python distribution which I believe can be downloaded/installed from Visual Studio installer, its available.
Also starting from Python 3.8 I guess the debug binaries are also shipped.
In case they are not, see this.
For the cmake part you can follow something like the following. This is a butchered version taken from my own cmake that I made for my python extension some time ago.
Read it and change it based on your own requirements it should be straight forward :
# NOTE:
# TORCH_LIB_DIRS needs to be set. When calling cmake you can specify them like this:
# cmake -DCMAKE_PREFIX_PATH="somewhere/libtorch/share/cmake" -DTORCH_LIB_DIRS="/somewhere/lib" ..
cmake_minimum_required(VERSION 3.1 FATAL_ERROR)
project(DAConvolution)
find_package(Torch REQUIRED)
# we are using the C++17, if you are not change this or remove it altogether
set(CMAKE_CXX_STANDARD 17)
#define where your headers and libs are, specify for example where your DaConvolution.h resides!
include_directories( somewhere/Yourinclude_dir ${TORCH_INCLUDE_DIRS})
set(DAConvolution_SRC ./DAConvolution.cpp )
LINK_DIRECTORIES(${TORCH_LIB_DIRS})
add_library(
DAConvolution
SHARED
${DAConvolution_SRC}
)
# if you use some custom libs, you previously built, specify its location here
# target_link_directories(DAConvolution PRIVATE somewhere/your_previously_built_stuff/libs)
target_link_libraries(DAConvolution ${TORCH_LIB_DIRS}/libc10.so)
target_link_libraries(DAConvolution ${TORCH_LIB_DIRS}/libtorch_cpu.so)
install(TARGETS DAConvolution LIBRARY DESTINATION lib )
Side note:
I made the cmake for Linux only, so under Windows, I always use Visual Studio (2019 to be exact), in the same way I explained earlier. its by far the best /easiest approach imho. Suit yourself and choose either of them that best fits your problem.
I am writing an F# library that targets the .NET Framework 3.5 with Visual Studio 2012. I would like to use the --standalone compiler flag so that the library contains all of the types needed to run by itself.
How can I set my F# project to compile with this flag with resorting to compiling with the command line?
You can add other compiler flags in the "Other flags" section of the project's properties.
I have set up static library builds of zlib and libpng. Both compile fine into .lib files. I am using MSVC 2010.
With this setup, to use libpng.lib, you need to link against zlib.lib as well. To avoid this, I'm trying to use lib.exe to link zlib into libpng directly. My invocation looks like:
call "C:/Program Files (x86)/Microsoft Visual Studio 10.0/VC/bin/lib.exe" /OUT:x64\Release\libpng2.lib x64\Release\libpng.lib ..\zlib\x64\Release\zlib.lib /LTCG
In both of their project settings, I explicitly set "Librarian->General->Target Machine" to MachineX64. And, using dumpbin, I can check that the relevant zlib.lib and libpng are both compiled for x64.
Additionally, "General->Whole Program Optimization" and "C/C++->Optimization->Whole Program Optimization" have identical values.
The problem only occurs for x64 Release configurations. x86 Debug, x86 Release, and x64 Debug all work fine.
EDIT: Specifically, the problem is that I get a C1905/LNK1257 error:
C1905: Front end and back end not compatible (must target same processor).
LNK1257: code generation failed
I ran into this problem with VS2012. The lib.exe you're calling is part of the x86 tools. In the amd64 subfolder in VC/bin you will find the x64 versions. Opening a Visual Studio x64 Win64 Command Prompt will set your PATH correctly or you can call the x64 lib.exe directly, specifying its full path as you are doing now.
It's possible to use code (and libraries) compiled with VisualC++ (so with .lib extension) in a project that will use GCC as compiler (and vice versa)? Or I have to rebuild them?
I'm trying to use SOCI 3.1 libraries that I have compiled with VisualC++ in a project that has GCC as compiler, but I'm getting some errors, and I don't know why..
You have to produce binaries for GCC using MinGW tools: reimp and dlltool. Here is MinGW wiki with complete explanation of the procedures: MSVC and MinGW DLLs
Short example:
reimp -d libmysql.lib
dlltool -k --input-def libmysql.def --dllname libmysql.dll --output-lib libmysql.a
reimp libmysql.lib
By the way, here is related thread on SOCI users mailing list which: MySQL Build fails. Look for useful links given in the thread.