cmake: Zephyr CMake package clean-up and minor fix

Fixes: zephyrproject-rtos#27375

This is a cleanup of the Zephyr CMake package export.
The code has been simplified so that the export now happens through a
CMake script. This avoids several generated CMake build files compared
to previous export mode, and thus removes the need for a CMake pristine
script.

A benefit of this cleanup is that it also fixes zephyrproject-rtos#27375.

Signed-off-by: Torsten Rasmussen <[email protected]>

Author: tejlmand

doc/guides/zephyr_cmake_package.rst

@@ -58,11 +58,16 @@ Zephyr CMake package is exported to the CMake user package registry using the fo
 
 .. code-block:: bash
 
-   cmake -S <PATH-TO-ZEPHYR>/share/zephyr-package/cmake -B <PATH-TO-ZEPHYR>/share/zephyr-package/cmake
-   cmake --build <PATH-TO-ZEPHYR>/share/zephyr-package/cmake --target pristine
+   cmake -P <PATH-TO-ZEPHYR>/share/zephyr-package/cmake/zephyr_export.cmake
+
+This will export the current Zephyr to the CMake user package registry.
+
+To also export the Zephyr Unittest CMake package, run the following command in addition:
+
+.. code-block:: bash
+
+   cmake -P <PATH-TO-ZEPHYR>/share/zephyrunittest-package/cmake/zephyr_export.cmake
 
-This will export the current Zephyr to the CMake user package registry and remove the temporary
-files generated by CMake during export.
 
 .. _zephyr_cmake_package_zephyr_base:
 

scripts/west_commands/export.py

@@ -5,7 +5,6 @@
 import argparse
 from pathlib import Path
 from shutil import rmtree
-from subprocess import CalledProcessError
 
 from west.commands import WestCommand
 from west import log
@@ -45,35 +44,20 @@ def do_run(self, args, unknown_args):
         # The 'share' subdirectory of the top level zephyr repository.
         share = Path(__file__).parents[2] / 'share'
 
-        run_cmake_and_clean_up(share / 'zephyr-package' / 'cmake')
-        run_cmake_and_clean_up(share / 'zephyrunittest-package' / 'cmake')
+        run_cmake_export(share / 'zephyr-package' / 'cmake')
+        run_cmake_export(share / 'zephyrunittest-package' / 'cmake')
 
-def run_cmake_and_clean_up(path):
-    # Run a package installation script, cleaning up afterwards.
+def run_cmake_export(path):
+    # Run a package installation script.
     #
     # Filtering out lines that start with -- ignores the normal
     # CMake status messages and instead only prints the important
     # information.
 
-    try:
-        lines = run_cmake(['-S', str(path), '-B', str(path)],
-                          capture_output=True)
-    finally:
-        msg = [line for line in lines if not line.startswith('-- ')]
-        log.inf('\n'.join(msg))
-        clean_up(path)
-
-def clean_up(path):
-    try:
-        run_cmake(['-P', str(path / 'pristine.cmake')],
-                  capture_output=True)
-    except CalledProcessError:
-        # Do our best to clean up even though CMake failed.
-        log.wrn(f'Failed to make {path} pristine; '
-                'removing known generated files...')
-        for subpath in ['CMakeCache.txt', 'CMakeFiles', 'build.ninja',
-                        'cmake_install.cmake', 'rules.ninja']:
-            remove_if_exists(Path(path) / subpath)
+    lines = run_cmake(['-P', str(path / 'zephyr_export.cmake')],
+                      capture_output=True)
+    msg = [line for line in lines if not line.startswith('-- ')]
+    log.inf('\n'.join(msg))
 
 def remove_if_exists(pathobj):
     if pathobj.is_file():

share/zephyr-package/cmake/CMakeLists.txt

@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: Apache-2.0
+
+# Purpose of this CMake file is to install a ZephyrConfig package reference in:
+# Unix/Linux/MacOS: ~/.cmake/packages/Zephyr
+# Windows         : HKEY_CURRENT_USER
+#
+# Having ZephyrConfig package allows for find_package(Zephyr) to work when ZEPHYR_BASE is not defined.
+#
+# Create the reference by running `cmake -P zephyr_export.cmake` in this directory.
+
+set(MD5_INFILE "current_path.txt")
+
+# We write CMAKE_CURRENT_LIST_DIR into MD5_INFILE, as the content of that file will be used for MD5 calculation.
+# This means we effectively get the MD5 of CMAKE_CURRENT_LIST_DIR which must be used for CMake user package registry.
+file(WRITE ${CMAKE_CURRENT_LIST_DIR}/${MD5_INFILE} ${CMAKE_CURRENT_LIST_DIR})
+execute_process(COMMAND ${CMAKE_COMMAND} -E md5sum ${CMAKE_CURRENT_LIST_DIR}/${MD5_INFILE}
+                OUTPUT_VARIABLE MD5_SUM
+)
+string(SUBSTRING ${MD5_SUM} 0 32 MD5_SUM)
+if(WIN32)
+  execute_process(COMMAND ${CMAKE_COMMAND}
+                  -E  write_regv
+                 "HKEY_CURRENT_USER\\Software\\Kitware\\CMake\\Packages\\Zephyr\;${MD5_SUM}" "${CMAKE_CURRENT_LIST_DIR}"
+)
+else()
+  file(WRITE $ENV{HOME}/.cmake/packages/Zephyr/${MD5_SUM} ${CMAKE_CURRENT_LIST_DIR})
+endif()
+
+message("Zephyr (${CMAKE_CURRENT_LIST_DIR})")
+message("has been added to the user package registry in:")
+if(WIN32)
+  message("HKEY_CURRENT_USER\\Software\\Kitware\\CMake\\Packages\\Zephyr\n")
+else()
+  message("~/.cmake/packages/Zephyr\n")
+endif()
+
+file(REMOVE ${CMAKE_CURRENT_LIST_DIR}/ZephyrPackagePath.txt)

share/zephyr-package/cmake/pristine.cmake

@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: Apache-2.0
+
+# Purpose of this CMake file is to install a ZephyrUnittestConfig package reference in:
+# Unix/Linux/MacOS: ~/.cmake/packages/ZephyrUnittest
+# Windows         : HKEY_CURRENT_USER
+#
+# Having ZephyrUnittestConfig package allows for find_package(ZephyrUnittest) to work when ZEPHYR_BASE is not defined.
+#
+# Create the reference by running `cmake -P zephyr_export.cmake` in this directory.
+
+set(MD5_INFILE "current_path.txt")
+
+# We write CMAKE_CURRENT_LIST_DIR into MD5_INFILE, as the content of that file will be used for MD5 calculation.
+# This means we effectively get the MD5 of CMAKE_CURRENT_LIST_DIR which must be used for CMake user package registry.
+file(WRITE ${CMAKE_CURRENT_LIST_DIR}/${MD5_INFILE} ${CMAKE_CURRENT_LIST_DIR})
+execute_process(COMMAND ${CMAKE_COMMAND} -E md5sum ${CMAKE_CURRENT_LIST_DIR}/${MD5_INFILE}
+                OUTPUT_VARIABLE MD5_SUM
+)
+string(SUBSTRING ${MD5_SUM} 0 32 MD5_SUM)
+if(WIN32)
+  execute_process(COMMAND ${CMAKE_COMMAND}
+                  -E  write_regv
+                 "HKEY_CURRENT_USER\\Software\\Kitware\\CMake\\Packages\\ZephyrUnittest\;${MD5_SUM}" "${CMAKE_CURRENT_LIST_DIR}"
+)
+else()
+  file(WRITE $ENV{HOME}/.cmake/packages/ZephyrUnittest/${MD5_SUM} ${CMAKE_CURRENT_LIST_DIR})
+endif()
+
+message("ZephyrUnittest (${CMAKE_CURRENT_LIST_DIR})")
+message("has been added to the user package registry in:")
+if(WIN32)
+  message("HKEY_CURRENT_USER\\Software\\Kitware\\CMake\\Packages\\ZephyrUnittest\n")
+else()
+  message("~/.cmake/packages/ZephyrUnittest\n")
+endif()
+
+file(REMOVE ${CMAKE_CURRENT_LIST_DIR}/${MD5_INFILE})