CMake: replace usage of the mbed_add_cmake_directory_if_labels() function (#13754)

Directories that start with special prefixes (TARGET_, FEATURE_, COMPONENT_)  are added to the build based on Mbed target configuration from targets.json instead of calling utility function mbed_add_cmake_directory_if_labels().

Author: rajkan01

CMakeLists.txt

@@ -22,7 +22,6 @@ include(${MBED_ROOT}/tools/cmake/toolchains/${MBED_TOOLCHAIN}.cmake)
 enable_language(C CXX ASM)
 
 include(${MBED_ROOT}/tools/cmake/core.cmake)
-include(${MBED_ROOT}/tools/cmake/util.cmake)
 include(${MBED_ROOT}/tools/cmake/profile.cmake)
 
 add_library(mbed-os OBJECT)

cmsis/CMSIS_5/CMSIS/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-mbed_add_cmake_directory_if_labels("TARGET")
+if("CORTEX_A" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_CORTEX_A)
+elseif("CORTEX_M" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_CORTEX_M)
+endif()
 
 add_subdirectory(RTOS2)

docs/design-documents/tools/cmake.md

@@ -11,18 +11,21 @@ Two steps approach:
 
 Definitions and configurations would be defined in CMake files, an Mbed app configuration file (`/path/to/app/mbed_app.json`) and Mbed library configuration files (`/path/to/mbed-os/<LIBRARY_NAME>/mbed_lib.json`). `mbed-tools` would parse the Mbed library and app configuration files and generate an `mbed_config.cmake` file.
 
-The following rules must be respected for backward compatibility.
+The following rules must be respected to include special prefix directories (TARGET_, COMPONENT_ and FEATURE_).
 
-Target labels, components, and features defined in `/path/to/mbed-os/targets/targets.json` are used to help the build system determine which directories contain sources/include files to use in the build process. This is accomplished through a custom CMake function (`mbed_add_cmake_directory_if_labels`) to append a prefix (TARGET_, COMPONENT_ and FEATURE_) and add matching directories to the list of directories to process.
+Target labels, components, and features defined in `/path/to/mbed-os/targets/targets.json` are used to help the build system determine which directories contain sources/include files to use in the build process. 
 
-An example, to add `TARGET_STM` in the folder `targets` where we have folders like TARGET_NXP, TARGET_STM, etc:
+This is a problem as labels, components and features directories will most likely be renamed and will not necessarily use the special prefixes TARGET_, COMPONENT_ and FEATURE_ respectively. Whenever such directories are encountered, check the directory name without the special prefix in the CMake list `MBED_TARGET_LABELS` generated by `mbed-tools` then include the subdirectory to the build process if found.
 
-```
-mbed_add_cmake_directory_if_labels("TARGET")
-```
+For example when the user builds for the `NUCLEO_F411RE` Mbed target, `mbed-tools` includes the `STM` label to the  `MBED_TARGET_LABELS` list. `TARGET_STM` can only be added to the list of build directories as shown below:
 
-If a user selects for example target `NUCLEO_F411RE`, the target defines the label `STM`. As result, the target folder STM is included.
+```
+# CMake input source file: mbed-os/targets/CMakeList.txt
 
+if("STM" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_STM)
+endif()
+```
 The same could be applied to other labels like features or components.
 
 ## Mbed OS Core (Mbed OS repository)
@@ -36,7 +39,6 @@ A number of CMake scripts are contained in the `mbed-os/tools/cmake` directory:
 * `core.cmake` - selects the core script from the `cmake/cores` directory, based on the value of the `MBED_CPU_CORE` variable
 * `profile.cmake` - selects the profile script from the `cmake/profiles` directory, based on the value of the `MBED_PROFILE` variable
 * `toolchain.cmake` - selects the toolchain script from the `cmake/toolchains` directory, based on the value of the `MBED_TOOLCHAIN` variable
-* `util.cmake` - custom CMake helper functions and macros
 
 The next sections will describe static CMake files within Mbed OS Core repository.
 
@@ -64,7 +66,7 @@ Custom functions/macros used within Mbed OS.
 
 ### 7. Component `CMakeLists.txt` Entry Point
 
-This file statically defines the build specification of an Mbed OS component. It contains conditional statements that depend on the configuration parameters generated by `mbed-tools`. The component entry points make use of functions/macros defined in `util.cmake` to conditionally include or exclude directories.
+This file statically defines the build specification of an Mbed OS component. It contains conditional statements that depend on the configuration parameters generated by `mbed-tools`.
 The rule of thumb is to not expose header files that are internal. We would like to avoid having everything in the include paths as we do now.
 
 ## Building an Application

hal/CMakeLists.txt

@@ -1,7 +1,9 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-mbed_add_cmake_directory_if_labels("TARGET")
+if("FLASH_CMSIS_ALGO" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_FLASH_CMSIS_ALGO)
+endif()
 
 add_subdirectory(usb)
 

hal/usb/CMakeLists.txt

@@ -1,8 +1,6 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-mbed_add_cmake_directory_if_labels("TARGET")
-
 target_include_directories(mbed-os
     PUBLIC
         include

targets/CMakeLists.txt

@@ -1,4 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-mbed_add_cmake_directory_if_labels("TARGET")
+if("Freescale" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_Freescale)
+elseif("NORDIC" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_NORDIC)     
+elseif("STM" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_STM)    
+endif()

targets/TARGET_Freescale/CMakeLists.txt

@@ -1,7 +1,9 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-mbed_add_cmake_directory_if_labels("TARGET")
+if("MCUXpresso_MCUS" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_MCUXpresso_MCUS)
+endif()
 
 target_include_directories(mbed-os
     PUBLIC

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/CMakeLists.txt

@@ -1,6 +1,12 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if("K66F" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_K66F)
+elseif("MCU_K64F" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_MCU_K64F)
+endif()
+
 target_sources(mbed-os
     PRIVATE
         fsl_common.c
@@ -24,5 +30,3 @@ target_include_directories(mbed-os
     PUBLIC
         api
 )
-
-mbed_add_cmake_directory_if_labels("TARGET")

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/TARGET_K66F/CMakeLists.txt

@@ -1,7 +1,9 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-mbed_add_cmake_directory_if_labels("TARGET")
+if("FRDM" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_FRDM)
+endif()
 
 add_subdirectory(device)
 

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/TARGET_MCU_K64F/CMakeLists.txt

@@ -2,7 +2,13 @@
 
 add_subdirectory(device)
 
-mbed_add_cmake_directory_if_labels("TARGET")
+if("FRDM" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_FRDM)
+elseif("HEXIWEAR" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_HEXIWEAR)
+elseif("SDT64B" IN_LIST MBED_TARGET_LABELS)
+    add_subdirectory(TARGET_SDT64B)
+endif()
 
 target_sources(mbed-os
     PRIVATE