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#
# Mini-Kconfig parser
#
# Copyright (c) 2015 Red Hat Inc.
#
# Authors:
# Paolo Bonzini <pbonzini@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2
# or, at your option, any later version. See the COPYING file in
# the top-level directory.
from __future__ import print_function
import os
import sys
import re
import random
__all__ = [ 'KconfigDataError', 'KconfigParserError',
'KconfigData', 'KconfigParser' ,
'defconfig', 'allyesconfig', 'allnoconfig', 'randconfig' ]
def debug_print(*args):
#print('# ' + (' '.join(str(x) for x in args)))
pass
# -------------------------------------------
# KconfigData implements the Kconfig semantics. For now it can only
# detect undefined symbols, i.e. symbols that were referenced in
# assignments or dependencies but were not declared with "config FOO".
#
# Semantic actions are represented by methods called do_*. The do_var
# method return the semantic value of a variable (which right now is
# just its name).
# -------------------------------------------
class KconfigDataError(Exception):
def __init__(self, msg):
self.msg = msg
def __str__(self):
return self.msg
allyesconfig = lambda x: True
allnoconfig = lambda x: False
defconfig = lambda x: x
randconfig = lambda x: random.randint(0, 1) == 1
class KconfigData:
class Expr:
def __and__(self, rhs):
return KconfigData.AND(self, rhs)
def __or__(self, rhs):
return KconfigData.OR(self, rhs)
def __invert__(self):
return KconfigData.NOT(self)
# Abstract methods
def add_edges_to(self, var):
pass
def evaluate(self):
assert False
class AND(Expr):
def __init__(self, lhs, rhs):
self.lhs = lhs
self.rhs = rhs
def __str__(self):
return "(%s && %s)" % (self.lhs, self.rhs)
def add_edges_to(self, var):
self.lhs.add_edges_to(var)
self.rhs.add_edges_to(var)
def evaluate(self):
return self.lhs.evaluate() and self.rhs.evaluate()
class OR(Expr):
def __init__(self, lhs, rhs):
self.lhs = lhs
self.rhs = rhs
def __str__(self):
return "(%s || %s)" % (self.lhs, self.rhs)
def add_edges_to(self, var):
self.lhs.add_edges_to(var)
self.rhs.add_edges_to(var)
def evaluate(self):
return self.lhs.evaluate() or self.rhs.evaluate()
class NOT(Expr):
def __init__(self, lhs):
self.lhs = lhs
def __str__(self):
return "!%s" % (self.lhs)
def add_edges_to(self, var):
self.lhs.add_edges_to(var)
def evaluate(self):
return not self.lhs.evaluate()
class Var(Expr):
def __init__(self, name):
self.name = name
self.value = None
self.outgoing = set()
self.clauses_for_var = list()
def __str__(self):
return self.name
def has_value(self):
return not (self.value is None)
def set_value(self, val, clause):
self.clauses_for_var.append(clause)
if self.has_value() and self.value != val:
print("The following clauses were found for " + self.name)
for i in self.clauses_for_var:
print(" " + str(i), file=sys.stderr)
raise KconfigDataError('contradiction between clauses when setting %s' % self)
debug_print("=> %s is now %s" % (self.name, val))
self.value = val
# depth first search of the dependency graph
def dfs(self, visited, f):
if self in visited:
return
visited.add(self)
for v in self.outgoing:
v.dfs(visited, f)
f(self)
def add_edges_to(self, var):
self.outgoing.add(var)
def evaluate(self):
if not self.has_value():
raise KconfigDataError('cycle found including %s' % self)
return self.value
class Clause:
def __init__(self, dest):
self.dest = dest
def priority(self):
return 0
def process(self):
pass
class AssignmentClause(Clause):
def __init__(self, dest, value):
KconfigData.Clause.__init__(self, dest)
self.value = value
def __str__(self):
return "CONFIG_%s=%s" % (self.dest, 'y' if self.value else 'n')
def process(self):
self.dest.set_value(self.value, self)
class DefaultClause(Clause):
def __init__(self, dest, value, cond=None):
KconfigData.Clause.__init__(self, dest)
self.value = value
self.cond = cond
if not (self.cond is None):
self.cond.add_edges_to(self.dest)
def __str__(self):
value = 'y' if self.value else 'n'
if self.cond is None:
return "config %s default %s" % (self.dest, value)
else:
return "config %s default %s if %s" % (self.dest, value, self.cond)
def priority(self):
# Defaults are processed just before leaving the variable
return -1
def process(self):
if not self.dest.has_value() and \
(self.cond is None or self.cond.evaluate()):
self.dest.set_value(self.value, self)
class DependsOnClause(Clause):
def __init__(self, dest, expr):
KconfigData.Clause.__init__(self, dest)
self.expr = expr
self.expr.add_edges_to(self.dest)
def __str__(self):
return "config %s depends on %s" % (self.dest, self.expr)
def process(self):
if not self.expr.evaluate():
self.dest.set_value(False, self)
class SelectClause(Clause):
def __init__(self, dest, cond):
KconfigData.Clause.__init__(self, dest)
self.cond = cond
self.cond.add_edges_to(self.dest)
def __str__(self):
return "select %s if %s" % (self.dest, self.cond)
def process(self):
if self.cond.evaluate():
self.dest.set_value(True, self)
def __init__(self, value_mangler=defconfig):
self.value_mangler = value_mangler
self.previously_included = []
self.incl_info = None
self.defined_vars = set()
self.referenced_vars = dict()
self.clauses = list()
# semantic analysis -------------
def check_undefined(self):
undef = False
for i in self.referenced_vars:
if not (i in self.defined_vars):
print("undefined symbol %s" % (i), file=sys.stderr)
undef = True
return undef
def compute_config(self):
if self.check_undefined():
raise KconfigDataError("there were undefined symbols")
return None
debug_print("Input:")
for clause in self.clauses:
debug_print(clause)
debug_print("\nDependency graph:")
for i in self.referenced_vars:
debug_print(i, "->", [str(x) for x in self.referenced_vars[i].outgoing])
# The reverse of the depth-first order is the topological sort
dfo = dict()
visited = set()
debug_print("\n")
def visit_fn(var):
debug_print(var, "has DFS number", len(dfo))
dfo[var] = len(dfo)
for name, v in self.referenced_vars.items():
self.do_default(v, False)
v.dfs(visited, visit_fn)
# Put higher DFS numbers and higher priorities first. This
# places the clauses in topological order and places defaults
# after assignments and dependencies.
self.clauses.sort(key=lambda x: (-dfo[x.dest], -x.priority()))
debug_print("\nSorted clauses:")
for clause in self.clauses:
debug_print(clause)
clause.process()
debug_print("")
values = dict()
for name, v in self.referenced_vars.items():
debug_print("Evaluating", name)
values[name] = v.evaluate()
return values
# semantic actions -------------
def do_declaration(self, var):
if (var in self.defined_vars):
raise KconfigDataError('variable "' + var + '" defined twice')
self.defined_vars.add(var.name)
# var is a string with the variable's name.
def do_var(self, var):
if (var in self.referenced_vars):
return self.referenced_vars[var]
var_obj = self.referenced_vars[var] = KconfigData.Var(var)
return var_obj
def do_assignment(self, var, val):
self.clauses.append(KconfigData.AssignmentClause(var, val))
def do_default(self, var, val, cond=None):
val = self.value_mangler(val)
self.clauses.append(KconfigData.DefaultClause(var, val, cond))
def do_depends_on(self, var, expr):
self.clauses.append(KconfigData.DependsOnClause(var, expr))
def do_select(self, var, symbol, cond=None):
cond = (cond & var) if cond is not None else var
self.clauses.append(KconfigData.SelectClause(symbol, cond))
def do_imply(self, var, symbol, cond=None):
# "config X imply Y [if COND]" is the same as
# "config Y default y if X [&& COND]"
cond = (cond & var) if cond is not None else var
self.do_default(symbol, True, cond)
# -------------------------------------------
# KconfigParser implements a recursive descent parser for (simplified)
# Kconfig syntax.
# -------------------------------------------
# tokens table
TOKENS = {}
TOK_NONE = -1
TOK_LPAREN = 0; TOKENS[TOK_LPAREN] = '"("';
TOK_RPAREN = 1; TOKENS[TOK_RPAREN] = '")"';
TOK_EQUAL = 2; TOKENS[TOK_EQUAL] = '"="';
TOK_AND = 3; TOKENS[TOK_AND] = '"&&"';
TOK_OR = 4; TOKENS[TOK_OR] = '"||"';
TOK_NOT = 5; TOKENS[TOK_NOT] = '"!"';
TOK_DEPENDS = 6; TOKENS[TOK_DEPENDS] = '"depends"';
TOK_ON = 7; TOKENS[TOK_ON] = '"on"';
TOK_SELECT = 8; TOKENS[TOK_SELECT] = '"select"';
TOK_IMPLY = 9; TOKENS[TOK_IMPLY] = '"imply"';
TOK_CONFIG = 10; TOKENS[TOK_CONFIG] = '"config"';
TOK_DEFAULT = 11; TOKENS[TOK_DEFAULT] = '"default"';
TOK_Y = 12; TOKENS[TOK_Y] = '"y"';
TOK_N = 13; TOKENS[TOK_N] = '"n"';
TOK_SOURCE = 14; TOKENS[TOK_SOURCE] = '"source"';
TOK_BOOL = 15; TOKENS[TOK_BOOL] = '"bool"';
TOK_IF = 16; TOKENS[TOK_IF] = '"if"';
TOK_ID = 17; TOKENS[TOK_ID] = 'identifier';
TOK_EOF = 18; TOKENS[TOK_EOF] = 'end of file';
class KconfigParserError(Exception):
def __init__(self, parser, msg, tok=None):
self.loc = parser.location()
tok = tok or parser.tok
if tok != TOK_NONE:
location = TOKENS.get(tok, None) or ('"%s"' % tok)
msg = '%s before %s' % (msg, location)
self.msg = msg
def __str__(self):
return "%s: %s" % (self.loc, self.msg)
class KconfigParser:
@classmethod
def parse(self, fp, mode=None):
data = KconfigData(mode or KconfigParser.defconfig)
parser = KconfigParser(data)
parser.parse_file(fp)
return data
def __init__(self, data):
self.data = data
def parse_file(self, fp):
self.abs_fname = os.path.abspath(fp.name)
self.fname = fp.name
self.data.previously_included.append(self.abs_fname)
self.src = fp.read()
if self.src == '' or self.src[-1] != '\n':
self.src += '\n'
self.cursor = 0
self.line = 1
self.line_pos = 0
self.get_token()
self.parse_config()
def do_assignment(self, var, val):
if not var.startswith("CONFIG_"):
raise Error('assigned variable should start with CONFIG_')
var = self.data.do_var(var[7:])
self.data.do_assignment(var, val)
# file management -----
def error_path(self):
inf = self.data.incl_info
res = ""
while inf:
res = ("In file included from %s:%d:\n" % (inf['file'],
inf['line'])) + res
inf = inf['parent']
return res
def location(self):
col = 1
for ch in self.src[self.line_pos:self.pos]:
if ch == '\t':
col += 8 - ((col - 1) % 8)
else:
col += 1
return '%s%s:%d:%d' %(self.error_path(), self.fname, self.line, col)
def do_include(self, include):
incl_abs_fname = os.path.join(os.path.dirname(self.abs_fname),
include)
# catch inclusion cycle
inf = self.data.incl_info
while inf:
if incl_abs_fname == os.path.abspath(inf['file']):
raise KconfigParserError(self, "Inclusion loop for %s"
% include)
inf = inf['parent']
# skip multiple include of the same file
if incl_abs_fname in self.data.previously_included:
return
try:
fp = open(incl_abs_fname, 'r')
except IOError as e:
raise KconfigParserError(self,
'%s: %s' % (e.strerror, include))
inf = self.data.incl_info
self.data.incl_info = { 'file': self.fname, 'line': self.line,
'parent': inf }
KconfigParser(self.data).parse_file(fp)
self.data.incl_info = inf
# recursive descent parser -----
# y_or_n: Y | N
def parse_y_or_n(self):
if self.tok == TOK_Y:
self.get_token()
return True
if self.tok == TOK_N:
self.get_token()
return False
raise KconfigParserError(self, 'Expected "y" or "n"')
# var: ID
def parse_var(self):
if self.tok == TOK_ID:
val = self.val
self.get_token()
return self.data.do_var(val)
else:
raise KconfigParserError(self, 'Expected identifier')
# assignment_var: ID (starting with "CONFIG_")
def parse_assignment_var(self):
if self.tok == TOK_ID:
val = self.val
if not val.startswith("CONFIG_"):
raise KconfigParserError(self,
'Expected identifier starting with "CONFIG_"', TOK_NONE)
self.get_token()
return self.data.do_var(val[7:])
else:
raise KconfigParserError(self, 'Expected identifier')
# assignment: var EQUAL y_or_n
def parse_assignment(self):
var = self.parse_assignment_var()
if self.tok != TOK_EQUAL:
raise KconfigParserError(self, 'Expected "="')
self.get_token()
self.data.do_assignment(var, self.parse_y_or_n())
# primary: NOT primary
# | LPAREN expr RPAREN
# | var
def parse_primary(self):
if self.tok == TOK_NOT:
self.get_token()
val = ~self.parse_primary()
elif self.tok == TOK_LPAREN:
self.get_token()
val = self.parse_expr()
if self.tok != TOK_RPAREN:
raise KconfigParserError(self, 'Expected ")"')
self.get_token()
elif self.tok == TOK_ID:
val = self.parse_var()
else:
raise KconfigParserError(self, 'Expected "!" or "(" or identifier')
return val
# disj: primary (OR primary)*
def parse_disj(self):
lhs = self.parse_primary()
while self.tok == TOK_OR:
self.get_token()
lhs = lhs | self.parse_primary()
return lhs
# expr: disj (AND disj)*
def parse_expr(self):
lhs = self.parse_disj()
while self.tok == TOK_AND:
self.get_token()
lhs = lhs & self.parse_disj()
return lhs
# condition: IF expr
# | empty
def parse_condition(self):
if self.tok == TOK_IF:
self.get_token()
return self.parse_expr()
else:
return None
# property: DEFAULT y_or_n condition
# | DEPENDS ON expr
# | SELECT var condition
# | BOOL
def parse_property(self, var):
if self.tok == TOK_DEFAULT:
self.get_token()
val = self.parse_y_or_n()
cond = self.parse_condition()
self.data.do_default(var, val, cond)
elif self.tok == TOK_DEPENDS:
self.get_token()
if self.tok != TOK_ON:
raise KconfigParserError(self, 'Expected "on"')
self.get_token()
self.data.do_depends_on(var, self.parse_expr())
elif self.tok == TOK_SELECT:
self.get_token()
symbol = self.parse_var()
cond = self.parse_condition()
self.data.do_select(var, symbol, cond)
elif self.tok == TOK_IMPLY:
self.get_token()
symbol = self.parse_var()
cond = self.parse_condition()
self.data.do_imply(var, symbol, cond)
elif self.tok == TOK_BOOL:
self.get_token()
else:
raise KconfigParserError(self, 'Error in recursive descent?')
# properties: properties property
# | /* empty */
def parse_properties(self, var):
had_default = False
while self.tok == TOK_DEFAULT or self.tok == TOK_DEPENDS or \
self.tok == TOK_SELECT or self.tok == TOK_BOOL or \
self.tok == TOK_IMPLY:
self.parse_property(var)
# for nicer error message
if self.tok != TOK_SOURCE and self.tok != TOK_CONFIG and \
self.tok != TOK_ID and self.tok != TOK_EOF:
raise KconfigParserError(self, 'expected "source", "config", identifier, '
+ '"default", "depends on", "imply" or "select"')
# declaration: config var properties
def parse_declaration(self):
if self.tok == TOK_CONFIG:
self.get_token()
var = self.parse_var()
self.data.do_declaration(var)
self.parse_properties(var)
else:
raise KconfigParserError(self, 'Error in recursive descent?')
# clause: SOURCE
# | declaration
# | assignment
def parse_clause(self):
if self.tok == TOK_SOURCE:
val = self.val
self.get_token()
self.do_include(val)
elif self.tok == TOK_CONFIG:
self.parse_declaration()
elif self.tok == TOK_ID:
self.parse_assignment()
else:
raise KconfigParserError(self, 'expected "source", "config" or identifier')
# config: clause+ EOF
def parse_config(self):
while self.tok != TOK_EOF:
self.parse_clause()
return self.data
# scanner -----
def get_token(self):
while True:
self.tok = self.src[self.cursor]
self.pos = self.cursor
self.cursor += 1
self.val = None
self.tok = self.scan_token()
if self.tok is not None:
return
def check_keyword(self, rest):
if not self.src.startswith(rest, self.cursor):
return False
length = len(rest)
if self.src[self.cursor + length].isalnum() or self.src[self.cursor + length] == '_':
return False
self.cursor += length
return True
def scan_token(self):
if self.tok == '#':
self.cursor = self.src.find('\n', self.cursor)
return None
elif self.tok == '=':
return TOK_EQUAL
elif self.tok == '(':
return TOK_LPAREN
elif self.tok == ')':
return TOK_RPAREN
elif self.tok == '&' and self.src[self.pos+1] == '&':
self.cursor += 1
return TOK_AND
elif self.tok == '|' and self.src[self.pos+1] == '|':
self.cursor += 1
return TOK_OR
elif self.tok == '!':
return TOK_NOT
elif self.tok == 'd' and self.check_keyword("epends"):
return TOK_DEPENDS
elif self.tok == 'o' and self.check_keyword("n"):
return TOK_ON
elif self.tok == 's' and self.check_keyword("elect"):
return TOK_SELECT
elif self.tok == 'i' and self.check_keyword("mply"):
return TOK_IMPLY
elif self.tok == 'c' and self.check_keyword("onfig"):
return TOK_CONFIG
elif self.tok == 'd' and self.check_keyword("efault"):
return TOK_DEFAULT
elif self.tok == 'b' and self.check_keyword("ool"):
return TOK_BOOL
elif self.tok == 'i' and self.check_keyword("f"):
return TOK_IF
elif self.tok == 'y' and self.check_keyword(""):
return TOK_Y
elif self.tok == 'n' and self.check_keyword(""):
return TOK_N
elif (self.tok == 's' and self.check_keyword("ource")) or \
self.tok == 'i' and self.check_keyword("nclude"):
# source FILENAME
# include FILENAME
while self.src[self.cursor].isspace():
self.cursor += 1
start = self.cursor
self.cursor = self.src.find('\n', self.cursor)
self.val = self.src[start:self.cursor]
return TOK_SOURCE
elif self.tok.isalpha():
# identifier
while self.src[self.cursor].isalnum() or self.src[self.cursor] == '_':
self.cursor += 1
self.val = self.src[self.pos:self.cursor]
return TOK_ID
elif self.tok == '\n':
if self.cursor == len(self.src):
return TOK_EOF
self.line += 1
self.line_pos = self.cursor
elif not self.tok.isspace():
raise KconfigParserError(self, 'invalid input')
return None
if __name__ == '__main__':
argv = sys.argv
mode = defconfig
if len(sys.argv) > 1:
if argv[1] == '--defconfig':
del argv[1]
elif argv[1] == '--randconfig':
random.seed()
mode = randconfig
del argv[1]
elif argv[1] == '--allyesconfig':
mode = allyesconfig
del argv[1]
elif argv[1] == '--allnoconfig':
mode = allnoconfig
del argv[1]
if len(argv) == 1:
print ("%s: at least one argument is required" % argv[0], file=sys.stderr)
sys.exit(1)
if argv[1].startswith('-'):
print ("%s: invalid option %s" % (argv[0], argv[1]), file=sys.stderr)
sys.exit(1)
data = KconfigData(mode)
parser = KconfigParser(data)
external_vars = set()
for arg in argv[3:]:
m = re.match(r'^(CONFIG_[A-Z0-9_]+)=([yn]?)$', arg)
if m is not None:
name, value = m.groups()
parser.do_assignment(name, value == 'y')
external_vars.add(name[7:])
else:
fp = open(arg, 'r')
parser.parse_file(fp)
fp.close()
config = data.compute_config()
for key in sorted(config.keys()):
if key not in external_vars:
print ('CONFIG_%s=%s' % (key, ('y' if config[key] else 'n')))
deps = open(argv[2], 'w')
for fname in data.previously_included:
print ('%s: %s' % (argv[1], fname), file=deps)
deps.close()