Using HINTS for STM Toolchain Path

[robamu]

This causes toolchains found via the STM32_TOOLCHAIN_PATH variable
to take precedence over a toolchain in the system path.
Also updated README accordingly

Fixes #251 . Closes #265

[Hish15]

Hi,

What is the confidence on the TOOLCHAIN_BIN_PATH correctness?

If I quote cmake's find packages doc :

Search paths specified by the HINTS option. These should be paths computed by system introspection, such as a hint provided by the location of another item already found. Hard-coded guesses should be specified with the PATHS option.

[atsju]

Hi,

What is the confidence on the TOOLCHAIN_BIN_PATH correctness?

If I quote cmake's find packages doc :

Search paths specified by the HINTS option. These should be paths computed by system introspection, such as a hint provided by the location of another item already found. Hard-coded guesses should be specified with the PATHS option.

Hi,
I think you want documentation of find_program and not find_package. I agree spirit is exactly same. You can judge the confidence here :

stm32-cmake/cmake/stm32/common.cmake

Lines 16 to 45 in 8415560

	if(NOT STM32_TOOLCHAIN_PATH)
	if(DEFINED ENV{STM32_TOOLCHAIN_PATH})
	message(STATUS "Detected toolchain path STM32_TOOLCHAIN_PATH in environmental variables: ")
	message(STATUS "$ENV{STM32_TOOLCHAIN_PATH}")
	set(STM32_TOOLCHAIN_PATH $ENV{STM32_TOOLCHAIN_PATH})
	endif()
	if(NOT CMAKE_C_COMPILER)
	set(STM32_TOOLCHAIN_PATH "/usr")
	message(STATUS "No STM32_TOOLCHAIN_PATH specified, using default: " ${STM32_TOOLCHAIN_PATH})
	else()
	# keep only directory of compiler
	get_filename_component(STM32_TOOLCHAIN_PATH ${CMAKE_C_COMPILER} DIRECTORY)
	# remove the last /bin directory
	get_filename_component(STM32_TOOLCHAIN_PATH ${STM32_TOOLCHAIN_PATH} DIRECTORY)
	endif()
	file(TO_CMAKE_PATH "${STM32_TOOLCHAIN_PATH}" STM32_TOOLCHAIN_PATH)
	endif()
	if(NOT STM32_TARGET_TRIPLET)
	set(STM32_TARGET_TRIPLET "arm-none-eabi")
	message(STATUS "No STM32_TARGET_TRIPLET specified, using default: " ${STM32_TARGET_TRIPLET})
	endif()
	set(CMAKE_SYSTEM_NAME Generic)
	set(CMAKE_SYSTEM_PROCESSOR arm)
	set(TOOLCHAIN_SYSROOT "${STM32_TOOLCHAIN_PATH}/${STM32_TARGET_TRIPLET}")
	set(TOOLCHAIN_BIN_PATH "${STM32_TOOLCHAIN_PATH}/bin")
	set(TOOLCHAIN_INC_PATH "${STM32_TOOLCHAIN_PATH}/${STM32_TARGET_TRIPLET}/include")
	set(TOOLCHAIN_LIB_PATH "${STM32_TOOLCHAIN_PATH}/${STM32_TARGET_TRIPLET}/lib")

Maybe PATH is better than HINTS in the spirit but I doesn't work. See related issue.

[Hish15]

Well, we want things to work so lets go for the HINT thing then. cmake's documentation is quite poor on the difference between PATH and HINTS anyway.