scripts/*syscalls.py: sort os.walk() for a more deterministic build

[marc-hb]

Found by "disordered --shuffle-dirents=yes".

Sorting os.walk() in scripts/subfolder_list.py removes the randomness in
the following files:

build/zephyr/misc/generated/syscalls_subdirs.txt
build/zephyr/CMakeFiles/syscall_list_h_target.dir/ or build.ninja

Sorting os.walk() in scripts/parse_syscalls.py removes the randomness
in:

build/zephyr/misc/generated/syscalls.json
build/zephyr/include/generated/syscall_dispatch.c
build/zephyr/include/generated/syscall_list.h

Note my (limited so far) testing did not observe any randomness in any
object file that this would address; the main purpose here is to remove
a very large amount of noise in diffoscope.

Signed-off-by: Marc Herbert [email protected]

[codecov-io]

Codecov Report

Merging #13446 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #13446   +/-   ##
=======================================
  Coverage    52.5%    52.5%           
=======================================
  Files         318      318           
  Lines       46526    46526           
  Branches    10754    10754           
=======================================
  Hits        24429    24429           
  Misses      17198    17198           
  Partials     4899     4899

---

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[agross-oss]

Seems like a good change.

[SebastianBoe]

Very nice.

[marc-hb]

BTW it's possible right now to entirely nullify the output of diffoscope --exclude-directory-metadata hello_world/build.1/ hello_world/build.2/ where build.1 and build.2 are two consecutive hello_world/build/ with just this hack:

--- a/cmake/app/boilerplate.cmake
+++ b/cmake/app/boilerplate.cmake
@@ -28,6 +28,9 @@ cmake_minimum_required(VERSION 3.13.1)
 # CMP0002: "Logical target names must be globally unique"
 cmake_policy(SET CMP0002 NEW)
 
+SET(CMAKE_C_ARCHIVE_CREATE "<CMAKE_AR> -qcD <TARGET> <LINK_FLAGS> <OBJECTS>")
+SET(CMAKE_C_ARCHIVE_FINISH "<CMAKE_RANLIB> -D <TARGET>")
+
 if(NOT (${CMAKE_VERSION} VERSION_LESS "3.13.0"))
   # Use the old CMake behaviour until 3.13.x is required and the build
   # scripts have been ported to the new behaviour.

It's unrelated to disordered --shuffle-dirents=yes and needed either way.

[marc-hb]

Another determinism fix if you liked this one: PR #13608 git describe --abbrev=12