zephyr/scripts/kconfig/kconfig.py

279 lines
11 KiB
Python
Executable File

#!/usr/bin/env python3
# Writes/updates the zephyr/.config configuration file by merging configuration
# files passed as arguments, e.g. board *_defconfig and application prj.conf
# files.
#
# When fragments haven't changed, zephyr/.config is both the input and the
# output, which just updates it. This is handled in the CMake files.
#
# Also does various checks (most via Kconfiglib warnings).
import argparse
import os
import sys
import textwrap
# Zephyr doesn't use tristate symbols. They're supported here just to make the
# script a bit more generic.
from kconfiglib import Kconfig, split_expr, expr_value, expr_str, BOOL, \
TRISTATE, TRI_TO_STR, AND, OR
def main():
args = parse_args()
if args.zephyr_base:
os.environ['ZEPHYR_BASE'] = args.zephyr_base
print("Parsing " + args.kconfig_file)
kconf = Kconfig(args.kconfig_file, warn_to_stderr=False,
suppress_traceback=True)
if args.handwritten_input_configs:
# Warn for assignments to undefined symbols, but only for handwritten
# fragments, to avoid warnings-turned-errors when using an old
# configuration file together with updated Kconfig files
kconf.warn_assign_undef = True
# prj.conf may override settings from the board configuration, so
# disable warnings about symbols being assigned more than once
kconf.warn_assign_override = False
kconf.warn_assign_redun = False
# Load configuration files
print(kconf.load_config(args.configs_in[0]))
for config in args.configs_in[1:]:
# replace=False creates a merged configuration
print(kconf.load_config(config, replace=False))
if args.handwritten_input_configs:
# Check that there are no assignments to promptless symbols, which
# have no effect.
#
# This only makes sense when loading handwritten fragments and not when
# loading zephyr/.config, because zephyr/.config is configuration
# output and also assigns promptless symbols.
check_no_promptless_assign(kconf)
# Print warnings for symbols that didn't get the assigned value. Only
# do this for handwritten input too, to avoid likely unhelpful warnings
# when using an old configuration and updating Kconfig files.
check_assigned_sym_values(kconf)
check_assigned_choice_values(kconf)
if kconf.syms['WARN_EXPERIMENTAL'].tri_value == 2:
check_experimental(kconf)
# Hack: Force all symbols to be evaluated, to catch warnings generated
# during evaluation. Wait till the end to write the actual output files, so
# that we don't generate any output if there are warnings-turned-errors.
#
# Kconfiglib caches calculated symbol values internally, so this is still
# fast.
kconf.write_config(os.devnull)
if kconf.warnings:
# Put a blank line between warnings to make them easier to read
for warning in kconf.warnings:
print("\n" + warning, file=sys.stderr)
# Turn all warnings into errors, so that e.g. assignments to undefined
# Kconfig symbols become errors.
#
# A warning is generated by this script whenever a symbol gets a
# different value than the one it was assigned. Keep that one as just a
# warning for now.
err("Aborting due to Kconfig warnings")
# Write the merged configuration and the C header
print(kconf.write_config(args.config_out))
print(kconf.write_autoconf(args.header_out))
# Write the list of parsed Kconfig files to a file
write_kconfig_filenames(kconf, args.kconfig_list_out)
def check_no_promptless_assign(kconf):
# Checks that no promptless symbols are assigned
for sym in kconf.unique_defined_syms:
if sym.user_value is not None and promptless(sym):
err(f"""\
{sym.name_and_loc} is assigned in a configuration file, but is not directly
user-configurable (has no prompt). It gets its value indirectly from other
symbols. """ + SYM_INFO_HINT.format(sym))
def check_assigned_sym_values(kconf):
# Verifies that the values assigned to symbols "took" (matches the value
# the symbols actually got), printing warnings otherwise. Choice symbols
# are checked separately, in check_assigned_choice_values().
for sym in kconf.unique_defined_syms:
if sym.choice:
continue
user_value = sym.user_value
if user_value is None:
continue
# Tristate values are represented as 0, 1, 2. Having them as "n", "m",
# "y" is more convenient here, so convert.
if sym.type in (BOOL, TRISTATE):
user_value = TRI_TO_STR[user_value]
if user_value != sym.str_value:
msg = f"{sym.name_and_loc} was assigned the value '{user_value}'" \
f" but got the value '{sym.str_value}'. "
# List any unsatisfied 'depends on' dependencies in the warning
mdeps = missing_deps(sym)
if mdeps:
expr_strs = []
for expr in mdeps:
estr = expr_str(expr)
if isinstance(expr, tuple):
# Add () around dependencies that aren't plain symbols.
# Gives '(FOO || BAR) (=n)' instead of
# 'FOO || BAR (=n)', which might be clearer.
estr = f"({estr})"
expr_strs.append(f"{estr} "
f"(={TRI_TO_STR[expr_value(expr)]})")
msg += "Check these unsatisfied dependencies: " + \
", ".join(expr_strs) + ". "
warn(msg + SYM_INFO_HINT.format(sym))
def missing_deps(sym):
# check_assigned_sym_values() helper for finding unsatisfied dependencies.
#
# Given direct dependencies
#
# depends on <expr> && <expr> && ... && <expr>
#
# on 'sym' (which can also come from e.g. a surrounding 'if'), returns a
# list of all <expr>s with a value less than the value 'sym' was assigned
# ("less" instead of "not equal" just to be general and handle tristates,
# even though Zephyr doesn't use them).
#
# For string/int/hex symbols, just looks for <expr> = n.
#
# Note that <expr>s can be something more complicated than just a symbol,
# like 'FOO || BAR' or 'FOO = "string"'.
deps = split_expr(sym.direct_dep, AND)
if sym.type in (BOOL, TRISTATE):
return [dep for dep in deps if expr_value(dep) < sym.user_value]
# string/int/hex
return [dep for dep in deps if expr_value(dep) == 0]
def check_assigned_choice_values(kconf):
# Verifies that any choice symbols that were selected (by setting them to
# y) ended up as the selection, printing warnings otherwise.
#
# We check choice symbols separately to avoid warnings when two different
# choice symbols within the same choice are set to y. This might happen if
# a choice selection from a board defconfig is overridden in a prj.conf,
# for example. The last choice symbol set to y becomes the selection (and
# all other choice symbols get the value n).
#
# Without special-casing choices, we'd detect that the first symbol set to
# y ended up as n, and print a spurious warning.
for choice in kconf.unique_choices:
if choice.user_selection and \
choice.user_selection is not choice.selection:
warn(f"""\
The choice symbol {choice.user_selection.name_and_loc} was selected (set =y),
but {choice.selection.name_and_loc if choice.selection else "no symbol"} ended
up as the choice selection. """ + SYM_INFO_HINT.format(choice.user_selection))
# Hint on where to find symbol information. Used like
# SYM_INFO_HINT.format(sym).
SYM_INFO_HINT = """\
See http://docs.zephyrproject.org/latest/kconfig.html#CONFIG_{0.name} and/or
look up {0.name} in the menuconfig/guiconfig interface. The Application
Development Primer, Setting Configuration Values, and Kconfig - Tips and Best
Practices sections of the manual might be helpful too.\
"""
def check_experimental(kconf):
experimental = kconf.syms['EXPERIMENTAL']
dep_expr = experimental.rev_dep
if dep_expr is not kconf.n:
selectors = [s for s in split_expr(dep_expr, OR) if expr_value(s) == 2]
for selector in selectors:
selector_name = split_expr(selector, AND)[0].name
warn(f'Experimental symbol {selector_name} is enabled.')
def promptless(sym):
# Returns True if 'sym' has no prompt. Since the symbol might be defined in
# multiple locations, we need to check all locations.
return not any(node.prompt for node in sym.nodes)
def write_kconfig_filenames(kconf, kconfig_list_path):
# Writes a sorted list with the absolute paths of all parsed Kconfig files
# to 'kconfig_list_path'. The paths are realpath()'d, and duplicates are
# removed. This file is used by CMake to look for changed Kconfig files. It
# needs to be deterministic.
with open(kconfig_list_path, 'w') as out:
for path in sorted({os.path.realpath(os.path.join(kconf.srctree, path))
for path in kconf.kconfig_filenames}):
print(path, file=out)
def parse_args():
parser = argparse.ArgumentParser()
parser.add_argument("--handwritten-input-configs",
action="store_true",
help="Assume the input configuration fragments are "
"handwritten fragments and do additional checks "
"on them, like no promptless symbols being "
"assigned")
parser.add_argument("--zephyr-base",
help="Path to current Zephyr installation")
parser.add_argument("kconfig_file",
help="Top-level Kconfig file")
parser.add_argument("config_out",
help="Output configuration file")
parser.add_argument("header_out",
help="Output header file")
parser.add_argument("kconfig_list_out",
help="Output file for list of parsed Kconfig files")
parser.add_argument("configs_in",
nargs="+",
help="Input configuration fragments. Will be merged "
"together.")
return parser.parse_args()
def warn(msg):
# Use a large fill() width to try to avoid linebreaks in the symbol
# reference link, and add some extra newlines to set the message off from
# surrounding text (this usually gets printed as part of spammy CMake
# output)
print("\n" + textwrap.fill("warning: " + msg, 100) + "\n", file=sys.stderr)
def err(msg):
sys.exit("\n" + textwrap.fill("error: " + msg, 100) + "\n")
if __name__ == "__main__":
main()