Full build can occur without linker script or multiple linker scripts

[atsju]

It is possible to build example that won't work because there is no linker script called. Maybe there is a way to force user to either provide a linker script or information that will lead to automatic generation

Blinky example without linker script

if(BLINKY_F4_EXAMPLE)
    add_executable(stm32-blinky-f4 blinky.c stm32f4xx_hal_conf.h)
    target_link_libraries(stm32-blinky-f4
        HAL::STM32::F4::RCC
        HAL::STM32::F4::GPIO
        HAL::STM32::F4::CORTEX
        CMSIS::STM32::F407xx
        STM32::NoSys
    )
    stm32_print_size_of_target(stm32-blinky-f4)
    stm32_generate_hex_file(stm32-blinky-f4)
endif()

Notice the use ofCMSIS::STM32::F407xx instead of CMSIS::STM32::F407VG

Extract of documentation

CMSIS creates the following targets:

CMSIS::STM32::<FAMILY> (e.g. CMSIS::STM32::F4) - common includes, compiler flags and defines for family CMSIS::STM32::<TYPE> (e.g. CMSIS::STM32::F407xx) - common startup source for device type, depends on CMSIS::STM32::<FAMILY> CMSIS::STM32::<DEVICE> (e.g. CMSIS::STM32::F407VG) - linker script for device, depends on CMSIS::STM32::<TYPE>

This will provide 2 linker scripts

        CMSIS::STM32::WB55RG::M4
        STM32::NoSys
    )
    stm32_print_size_of_target(stm32-blinky-wb)
    stm32_add_linker_script(stm32-blinky-wb PRIVATE stm32wb55xx_flash_cm4.ld)

Should be avoided/warned by cmake

[TheSlowGrowth]

It seems there is still an easy configuration error where no linker file is actually used. Example:

target_link_libraries(targetName
    CMSIS::STM32::F103xB
)

Could a CMake warning be added for this case as well?