How should one set cmake ar/ranlib [duplicate] - cmake

Question

Problem:
After I run cmake to generate a project with a STATIC library, which completes successfully, both ninja and mingw32-make fail to make their targets at linking. For SHARED libraries or executables this same setup worked fine. I've tried this both for "Ninja" and "MinGW Makefiles" generators:
ninja output:
[2/2] Linking CXX static library hello_wsl.lib
FAILED: hello_wsl.lib
cmd.exe /C "cd . && "C:\Program Files\CMake\bin\cmake.exe" -E remove hello_wsl.lib && "" qc hello_wsl.lib CMakeFiles/hello_wsl.dir/lib_hello_world.cpp.obj && cd ."
"""" no se reconoce como un comando interno o externo,
programa o archivo por lotes ejecutable.
ninja: build stopped: subcommand failed.
mingw32-make output:
Scanning dependencies of target hello_wsl
[ 50%] Building CXX object CMakeFiles/hello_wsl.dir/lib_hello_world.cpp.obj
[100%] Linking CXX static library hello_wsl.lib
Error running link command: El parámetro no es correcto
CMakeFiles\hello_wsl.dir\build.make:93: recipe for target 'hello_wsl.lib' failed
mingw32-make.exe[2]: *** [hello_wsl.lib] Error 2
CMakeFiles\Makefile2:66: recipe for target 'CMakeFiles/hello_wsl.dir/all' failed
mingw32-make.exe[1]: *** [CMakeFiles/hello_wsl.dir/all] Error 2
Makefile:82: recipe for target 'all' failed
mingw32-make.exe: *** [all] Error 2
Also take a look at "project_root\build\CMakeFiles\hello_wsl.dir\link.txt" generated by "MinGW Makefiles":
"" qc hello_wsl.lib CMakeFiles/hello_wsl.dir/lib_hello_world.cpp.obj
Sample project, in steps, to reproduce the problem for "MinGW Makefiles":
Install CMake 3.8.0
Install MinGWx64 6.3 windows binaries (I've downloaded them from here)
Create a root folder for this project, I'll call it project_root in this sample.
Create these subfolders inside:
project_root\build
project_root\include
project_root\include\lib_hello_world
Create these files:
project_root\include\lib_hello_world\lib_hello_world.cpp:
#include <iostream>
class HelloWorldClass{
HelloWorldClass(){
std::cout << "Hello, world!" << std::endl;
}
};
project_root\include\lib_hello_world\CMakeLists.txt:
cmake_minimum_required(VERSION 3.8.0)
project(lib_hello_world)
add_library(lib_hello_world STATIC lib_hello_world.cpp)
project_root\toolchain.cmake:
# Target system (cross compile)
set(CMAKE_SYSTEM_NAME WindowsStore)
set(CMAKE_SYSTEM_VERSION 10.0)
# BIN utils
SET(CMAKE_AR "$ENV{MINGW_W64_BIN_DIR}/ar.exe")
SET(CMAKE_OBJCOPY "$ENV{MINGW_W64_BIN_DIR}/objcopy.exe")
SET(CMAKE_OBJDUMP "$ENV{MINGW_W64_BIN_DIR}/objdump.exe")
SET(CMAKE_RANLIB "$ENV{MINGW_W64_BIN_DIR}/ranlib.exe")
SET(CMAKE_NM "$ENV{MINGW_W64_BIN_DIR}/nm.exe")
SET(CMAKE_STRIP "$ENV{MINGW_W64_BIN_DIR}/strip.exe")
# C compiler
SET(CMAKE_C_COMPILER "$ENV{MINGW_W64_BIN_DIR}/gcc.exe")
# CXX compiler
SET(CMAKE_CXX_COMPILER "$ENV{MINGW_W64_BIN_DIR}/g++.exe")
# LINKER
SET(CMAKE_LINKER "$ENV{MINGW_W64_BIN_DIR}/ld.bfd.exe")
project_root\configure.bat:
#ECHO OFF
SETLOCAL
#ECHO OFF
REM Change these variables to the corresponding paths on your own system
SET "CMAKE_EXECUTABLE=C:\Program Files\CMake\bin\cmake.exe"
SET "MINGW_W64_BIN_DIR=C:/Program Files/MinGWx64/bin"
CD "%~dp0\build"
CALL "%CMAKE_EXECUTABLE%" "-DCMAKE_EXPORT_COMPILE_COMMANDS=ON" "-DCMAKE_BUILD_TYPE=Debug" -G "MinGW Makefiles" "-DCMAKE_MAKE_PROGRAM='%MINGW_W64_BIN_DIR%/mingw32-make.exe'" "-DCMAKE_TOOLCHAIN_FILE='%~dp0/toolchain.cmake'" "%~dp0/include/lib_hello_world"
ENDLOCAL
project_root\build.bat:
#ECHO OFF
SETLOCAL
#ECHO OFF
REM Change this variable to the corresponding path on your own system
SET "MINGW_W64_BIN_DIR=C:/Program Files/MinGWx64/bin"
CD "%~dp0\build"
CALL "%MINGW_W64_BIN_DIR%/mingw32-make.exe"
ENDLOCAL
Finally, open CMD and run the commands:
project_root\configure.bat
project_root\build.bat
This is a sketchy fix/workaround that I found:
Create this file:
project_root\fix.bat:
#ECHO OFF
SETLOCAL
#ECHO OFF
MOVE "%~dp0\build\CMakeCache.txt" ".\"
RMDIR "%~dp0\build" /S /Q
MKDIR "%~dp0\build"
MOVE "%~dp0\CMakeCache.txt" ".\build\"
ENDLOCAL
After reproducing the error, open CMD and run:
project_root\fix.bat
project_root\configure.bat
project_root\build.bat
ninja output after fix (successfully linked):
[2/2] Linking CXX static library hello_wsl.lib
mingw32-make after fix (successfully linked):
Scanning dependencies of target hello_wsl
[ 50%] Building CXX object CMakeFiles/hello_wsl.dir/lib_hello_world.cpp.obj
[100%] Linking CXX static library hello_wsl.lib
[100%] Built target hello_wsl
A few things I did to try to figure this out:
I made a backup of CMakeCache.txt (CMakeCache.txt.before_fix) before applying the fix and reruning configure and build. There was no diference between the CMakeCache.txt.before_fix and CMakeCache.txt files after reconfiguring and successfully building the project.
I also made a backup of "rules.ninja" and then compared them with FC. This is the output of FC "project_root\rules.ninja.before_fix" "project_root\build\rules.ninja":
Comparando archivos .\rules.ninja.before_fix y .\BUILD\RULES.NINJA
***** .\rules.ninja.before_fix
rule CXX_STATIC_LIBRARY_LINKER__lib_hello_world
command = cmd.exe /C "$PRE_LINK && "C:\Program Files\CMake\bin\cmake.exe" -E remove $TARGET_FILE && "" qc $TARGET_FILE $LINK_
FLAGS $in && $POST_BUILD"
description = Linking CXX static library $TARGET_FILE
***** .\BUILD\RULES.NINJA
rule CXX_STATIC_LIBRARY_LINKER__lib_hello_world
command = cmd.exe /C "$PRE_LINK && "C:\Program Files\CMake\bin\cmake.exe" -E remove $TARGET_FILE && C:\PROGRA~1\MinGWx64\bin\
ar.exe qc $TARGET_FILE $LINK_FLAGS $in && C:\PROGRA~1\MinGWx64\bin\ranlib.exe $TARGET_FILE && $POST_BUILD"
description = Linking CXX static library $TARGET_FILE
*****
And did the same for "MinGW Makefiles". This is the output of FC "project_root\link.txt.before_fix" "project_root\build\CMakeFiles\lib_hello_world.dir\link.txt":
Comparando archivos .\link.txt.before_fix y .\BUILD\CMAKEFILES\LIB_HELLO_WORLD.DIR\LINK.TXT
***** .\link.txt.before_fix
"" qc hello_wsl.lib CMakeFiles/hello_wsl.dir/lib_hello_world.cpp.obj
***** .\BUILD\CMAKEFILES\LIB_HELLO_WORLD.DIR\LINK.TXT
C:\PROGRA~1\MinGWx64\bin\ar.exe qc lib_hello_world.lib CMakeFiles/lib_hello_world.dir/lib_hello_world.cpp.obj
C:\PROGRA~1\MinGWx64\bin\ranlib.exe lib_hello_world.lib
*****

Answer 1

There is some specific about CMAKE_AR and CMAKE_RUNLIB variables: according to that bugreport they should be declared as CACHED:
SET(CMAKE_AR "$ENV{MINGW_W64_BIN_DIR}/ar.exe" CACHE FILEPATH "Arhiver")
SET(CMAKE_RANLIB "$ENV{MINGW_W64_BIN_DIR}/ranlib.exe" CACHE FILEPATH "Runlib")