cmake: Fix and cleanup CDDL dependencies

The main problem was an extra, unnecessary CMake re-run that happened at
the start of any build with CONFIG_SUIT_PROCESSOR=y. This had to do with
tracking CDDL file changes to trigger regeneration of zcbor files, which
was set up incorrectly.

On the initial CMake run, this module would do the following:

  1. Execute zcbor commands to generate some *.c, *.h, *.cmake files.
  2. Include the generated *.cmake files.
  3. Add custom commands and targets to regenerate the *.cmake files at
     build time, using the same commands from step 1.

Then, Ninja would start with generating the files again. This is because
whenever Ninja decides whether to run a command, it doesn't check if the
output files already exist; it only checks if (and when) it has executed
the command before. Here's the abridged output from `ninja -d explain`:

     ninja explain: command line not found in log for cose.cmake
     ninja explain: cose.cmake is dirty
     ninja explain: command line not found in log for manifest.cmake
     ninja explain: manifest.cmake is dirty
     [1/3] Generating cose.cmake
     [2/3] Generating manifest.cmake
     [2/3] Re-running CMake...

In principle, we cannot set up these files to be generated at both
configure time and build time. It only really makes sense to do it at
configure time, because rewriting CMake sources forces a re-run anyway.
Therefore, instead of using custom commands to track CDDL dependencies,
use the CMAKE_CONFIGURE_DEPENDS directory property.

While at it, refactor the module to move the zcbor generation code into
a common function for the `cose` and `manifest` libraries. This reduces
duplication and fixes another issue, where not all CDDL files were able
to trigger regeneration (such as `cose_encrypt.cddl`).

Signed-off-by: Grzegorz Swiderski <[email protected]>

CMakeLists.txt

@@ -12,88 +12,57 @@ else()
   set(ZCBOR_COMMAND ${PYTHON_EXECUTABLE} ${ZEPHYR_ZCBOR_MODULE_DIR}/zcbor/zcbor.py)
 endif()
 
-set(ZCBOR_DIR "${CMAKE_CURRENT_BINARY_DIR}")
+function(zcbor_generate_library name)
+  cmake_parse_arguments(arg "DECODE;ENCODE" "" "CDDL_FILES;ENTRY_TYPES" ${ARGN})
 
-# Generate and add COSE parser code
-set(ZCBOR_COMMAND_COSE
-  ${ZCBOR_COMMAND}
-    code
-    -c "${CMAKE_CURRENT_LIST_DIR}/cddl/cose_sign.cddl"
-    -c "${CMAKE_CURRENT_LIST_DIR}/cddl/cose_encrypt.cddl"
-    -d -e
-    -t COSE_Sign1_Tagged Sig_structure1
-       COSE_Encrypt_Tagged Enc_structure
-    --output-cmake cose.cmake
+  # Setup zcbor command arguments
+  list(TRANSFORM arg_CDDL_FILES PREPEND "--cddl;" OUTPUT_VARIABLE zcbor_code_args)
+  if(arg_DECODE)
+    list(APPEND zcbor_code_args --decode)
+  endif()
+  if(arg_ENCODE)
+    list(APPEND zcbor_code_args --encode)
+  endif()
+  list(APPEND zcbor_code_args
+    --entry-types ${arg_ENTRY_TYPES}
+    --output-cmake ${name}.cmake
     --copy-sources
-)
-
-if(NOT EXISTS "${ZCBOR_DIR}/cose.cmake")
-execute_process(
-  COMMAND ${ZCBOR_COMMAND_COSE}
-  WORKING_DIRECTORY ${ZCBOR_DIR}
-  COMMAND_ERROR_IS_FATAL ANY
-)
-endif()
-
-# Create cmake target to track changes in the input cddl file
-add_custom_command(
-  OUTPUT "${ZCBOR_DIR}/cose.cmake"
-  DEPENDS "${CMAKE_CURRENT_LIST_DIR}/cddl/cose_sign.cddl"
-  COMMAND ${ZCBOR_COMMAND_COSE}
-  WORKING_DIRECTORY "${ZCBOR_DIR}"
   )
-add_custom_target(zcbor_cose ALL
-  DEPENDS "${ZCBOR_DIR}/cose.cmake"
-  COMMENT "Generate cose encode/decode sources for parsing CBOR"
+  execute_process(
+    COMMAND ${ZCBOR_COMMAND} code ${zcbor_code_args}
+    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+    COMMAND_ERROR_IS_FATAL ANY
   )
+  include(${CMAKE_CURRENT_BINARY_DIR}/${name}.cmake)
 
-include("${ZCBOR_DIR}/cose.cmake")
-# Specify the absolute path for ZCBOR-generated code include directory
-target_include_directories(cose PUBLIC
-    ${ZCBOR_DIR}/include
-    )
+  # Track changes to input cddl files
+  set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${arg_CDDL_FILES})
+endfunction()
 
-# Generate and add SUIT envelope parser code
-set(ZCBOR_COMMAND_MANIFEST
-  ${ZCBOR_COMMAND}
-    code
-    -c "${CMAKE_CURRENT_LIST_DIR}/cddl/manifest.cddl"
-    -c "${CMAKE_CURRENT_LIST_DIR}/cddl/trust_domains.cddl"
-    -c "${CMAKE_CURRENT_LIST_DIR}/cddl/update_management.cddl"
-    -c "${CMAKE_CURRENT_LIST_DIR}/cddl/firmware_encryption.cddl"
-    -d
-    -t SUIT_Envelope_Tagged SUIT_Manifest SUIT_Shared_Sequence SUIT_Command_Sequence
-       SUIT_Condition SUIT_Directive SUIT_Shared_Commands SUIT_Text_Map SUIT_Digest
-       SUIT_Condition_Version_Comparison_Value SUIT_Parameter_Version_Match
-    --output-cmake manifest.cmake
-    --copy-sources
-)
-if(NOT EXISTS "${ZCBOR_DIR}/manifest.cmake")
-execute_process(
-  COMMAND ${ZCBOR_COMMAND_MANIFEST}
-  WORKING_DIRECTORY ${ZCBOR_DIR}
-  COMMAND_ERROR_IS_FATAL ANY
+# Generate and add COSE parser code
+zcbor_generate_library(cose
+  CDDL_FILES
+    ${CMAKE_CURRENT_LIST_DIR}/cddl/cose_sign.cddl
+    ${CMAKE_CURRENT_LIST_DIR}/cddl/cose_encrypt.cddl
+  DECODE ENCODE
+  ENTRY_TYPES
+    COSE_Sign1_Tagged Sig_structure1
+    COSE_Encrypt_Tagged Enc_structure
 )
-endif()
-
-# Create cmake target to track changes in the input cddl file
-add_custom_command(
-  OUTPUT "${ZCBOR_DIR}/manifest.cmake"
-  DEPENDS "${CMAKE_CURRENT_LIST_DIR}/cddl/manifest.cddl"
-  DEPENDS "${CMAKE_CURRENT_LIST_DIR}/cddl/trust_domains.cddl"
-  COMMAND ${ZCBOR_COMMAND_MANIFEST}
-  WORKING_DIRECTORY "${ZCBOR_DIR}"
-  )
-add_custom_target(zcbor_manifest ALL
-  DEPENDS "${ZCBOR_DIR}/manifest.cmake"
-  COMMENT "Generate manifest encode/decode sources for parsing CBOR"
-  )
 
-include("${ZCBOR_DIR}/manifest.cmake")
-# Specify the absolute path for ZCBOR-generated code include directory
-target_include_directories(manifest PUBLIC
-    ${ZCBOR_DIR}/include
-    )
+# Generate and add SUIT envelope parser code
+zcbor_generate_library(manifest
+  CDDL_FILES
+    ${CMAKE_CURRENT_LIST_DIR}/cddl/manifest.cddl
+    ${CMAKE_CURRENT_LIST_DIR}/cddl/trust_domains.cddl
+    ${CMAKE_CURRENT_LIST_DIR}/cddl/update_management.cddl
+    ${CMAKE_CURRENT_LIST_DIR}/cddl/firmware_encryption.cddl
+  DECODE
+  ENTRY_TYPES
+    SUIT_Envelope_Tagged SUIT_Manifest SUIT_Shared_Sequence SUIT_Command_Sequence
+    SUIT_Condition SUIT_Directive SUIT_Shared_Commands SUIT_Text_Map SUIT_Digest
+    SUIT_Condition_Version_Comparison_Value SUIT_Parameter_Version_Match
+)
 
 # Define SUIT library
 add_library(suit)