How to tell CMake to use Windows paths, not Cygwin ones? - cmake

Question

I am on Cygwin and I would like to call a compiler installed on Windows. I have an issue with the paths format.
With this very simple CMakeLists.txt:
cmake_minimum_required(VERSION 3.6)
set(CMAKE_SYSTEM_NAME Generic)
set(CMAKE_SYSTEM_PROCESSOR Cortex-M4)
set(CMAKE_C_COMPILER iccarm.exe)
set(CMAKE_CXX_COMPILER iccarm.exe)
set(CMAKE_ASM_COMPILER iasmarm.exe)
project("test" C)
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
if(NOT EXISTS main.c)
file(WRITE main.c "int main(void){return 0;}\n")
endif()
add_executable(
test
main.c
)
I get an issue when CMake checks for the compiler:
-- The C compiler identification is IAR
-- Check for working C compiler: /cygdrive/c/Program Files (x86)/IAR Systems/Embedded Workbench 8.0/arm/bin/iccarm.exe
-- Check for working C compiler: /cygdrive/c/Program Files (x86)/IAR Systems/Embedded Workbench 8.0/arm/bin/iccarm.exe -- broken
CMake Error at /usr/share/cmake-3.6.2/Modules/CMakeTestCCompiler.cmake:61 (message):
The C compiler "/cygdrive/c/Program Files (x86)/IAR Systems/Embedded
Workbench 8.0/arm/bin/iccarm.exe" is not able to compile a simple test
program.
It fails with the following output:
Change Dir: /cygdrive/c/Users/nobody/home/sandbox/cmakeiar/CMakeFiles/CMakeTmp
It is because CMake doesn't know, or perhaps it should know, that iccarm.exe is a Windows program that is expecting windows paths.
Is there a solution to give CMake this information?
I imaging something like:
if(PLATFORM_IS_CYGWIN)
set(CMAKE_IS_WINDOWS_EXECUTABLE iccarm.exe)
endif()

Answer 1

Turning my comments into an answer
Please be aware that Cygwin's CMake would give /cygdrive prefixes, but Windows installed CMake version won't.
I've run a test with your CMakeLists.txt, the IAR ARM compilers in my PATH environment and could successfully run from the Cygwin bash shell:
$ /cygdrive/c/Program\ Files/CMake/bin/cmake -G "Unix Makefiles" ..
-- The C compiler identification is IAR
-- Check for working C compiler: C:/Program Files (x86)/IAR Systems/Embedded Workbench 8.0/arm/bin/iccarm.exe
-- Check for working C compiler: C:/Program Files (x86)/IAR Systems/Embedded Workbench 8.0/arm/bin/iccarm.exe -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Configuring done
-- Generating done
-- Build files have been written to: ...
If I do just call cmake .. (the Cygwin version) I get the same errors you got.