1#!/usr/bin/env python3
2# SPDX-License-Identifier: GPL-2.0-only
3
4"""Find Kconfig symbols that are referenced but not defined."""
5
6# (c) 2014-2017 Valentin Rothberg <valentinrothberg@gmail.com>
7# (c) 2014 Stefan Hengelein <stefan.hengelein@fau.de>
8#
9
10
11import argparse
12import difflib
13import os
14import re
15import signal
16import subprocess
17import sys
18from multiprocessing import Pool, cpu_count
19
20
21# regex expressions
22OPERATORS = r"&|\(|\)|\||\!"
23SYMBOL = r"(?:\w*[A-Z0-9]\w*){2,}"
24DEF = r"^\s*(?:menu){,1}config\s+(" + SYMBOL + r")\s*"
25EXPR = r"(?:" + OPERATORS + r"|\s|" + SYMBOL + r")+"
26DEFAULT = r"default\s+.*?(?:if\s.+){,1}"
27STMT = r"^\s*(?:if|select|imply|depends\s+on|(?:" + DEFAULT + r"))\s+" + EXPR
28SOURCE_SYMBOL = r"(?:\W|\b)+[D]{,1}CONFIG_(" + SYMBOL + r")"
29
30# regex objects
31REGEX_FILE_KCONFIG = re.compile(r".*Kconfig[\.\w+\-]*$")
32REGEX_SYMBOL = re.compile(r'(?!\B)' + SYMBOL + r'(?!\B)')
33REGEX_SOURCE_SYMBOL = re.compile(SOURCE_SYMBOL)
34REGEX_KCONFIG_DEF = re.compile(DEF)
35REGEX_KCONFIG_EXPR = re.compile(EXPR)
36REGEX_KCONFIG_STMT = re.compile(STMT)
37REGEX_FILTER_SYMBOLS = re.compile(r"[A-Za-z0-9]$")
38REGEX_NUMERIC = re.compile(r"0[xX][0-9a-fA-F]+|[0-9]+")
39REGEX_QUOTES = re.compile("(\"(.*?)\")")
40
41
42def parse_options():
43    """The user interface of this module."""
44    usage = "Run this tool to detect Kconfig symbols that are referenced but " \
45            "not defined in Kconfig.  If no option is specified, "             \
46            "checkkconfigsymbols defaults to check your current tree.  "       \
47            "Please note that specifying commits will 'git reset --hard\' "    \
48            "your current tree!  You may save uncommitted changes to avoid "   \
49            "losing data."
50
51    parser = argparse.ArgumentParser(description=usage)
52
53    parser.add_argument('-c', '--commit', dest='commit', action='store',
54                        default="",
55                        help="check if the specified commit (hash) introduces "
56                             "undefined Kconfig symbols")
57
58    parser.add_argument('-d', '--diff', dest='diff', action='store',
59                        default="",
60                        help="diff undefined symbols between two commits "
61                             "(e.g., -d commmit1..commit2)")
62
63    parser.add_argument('-f', '--find', dest='find', action='store_true',
64                        default=False,
65                        help="find and show commits that may cause symbols to be "
66                             "missing (required to run with --diff)")
67
68    parser.add_argument('-i', '--ignore', dest='ignore', action='store',
69                        default="",
70                        help="ignore files matching this Python regex "
71                             "(e.g., -i '.*defconfig')")
72
73    parser.add_argument('-s', '--sim', dest='sim', action='store', default="",
74                        help="print a list of max. 10 string-similar symbols")
75
76    parser.add_argument('--force', dest='force', action='store_true',
77                        default=False,
78                        help="reset current Git tree even when it's dirty")
79
80    parser.add_argument('--no-color', dest='color', action='store_false',
81                        default=True,
82                        help="don't print colored output (default when not "
83                             "outputting to a terminal)")
84
85    args = parser.parse_args()
86
87    if args.commit and args.diff:
88        sys.exit("Please specify only one option at once.")
89
90    if args.diff and not re.match(r"^[\w\-\.\^]+\.\.[\w\-\.\^]+$", args.diff):
91        sys.exit("Please specify valid input in the following format: "
92                 "\'commit1..commit2\'")
93
94    if args.commit or args.diff:
95        if not args.force and tree_is_dirty():
96            sys.exit("The current Git tree is dirty (see 'git status').  "
97                     "Running this script may\ndelete important data since it "
98                     "calls 'git reset --hard' for some performance\nreasons. "
99                     " Please run this script in a clean Git tree or pass "
100                     "'--force' if you\nwant to ignore this warning and "
101                     "continue.")
102
103    if args.commit:
104        if args.commit.startswith('HEAD'):
105            sys.exit("The --commit option can't use the HEAD ref")
106
107        args.find = False
108
109    if args.ignore:
110        try:
111            re.match(args.ignore, "this/is/just/a/test.c")
112        except:
113            sys.exit("Please specify a valid Python regex.")
114
115    return args
116
117
118def print_undefined_symbols():
119    """Main function of this module."""
120    args = parse_options()
121
122    global COLOR
123    COLOR = args.color and sys.stdout.isatty()
124
125    if args.sim and not args.commit and not args.diff:
126        sims = find_sims(args.sim, args.ignore)
127        if sims:
128            print("%s: %s" % (yel("Similar symbols"), ', '.join(sims)))
129        else:
130            print("%s: no similar symbols found" % yel("Similar symbols"))
131        sys.exit(0)
132
133    # dictionary of (un)defined symbols
134    defined = {}
135    undefined = {}
136
137    if args.commit or args.diff:
138        head = get_head()
139
140        # get commit range
141        commit_a = None
142        commit_b = None
143        if args.commit:
144            commit_a = args.commit + "~"
145            commit_b = args.commit
146        elif args.diff:
147            split = args.diff.split("..")
148            commit_a = split[0]
149            commit_b = split[1]
150            undefined_a = {}
151            undefined_b = {}
152
153        # get undefined items before the commit
154        reset(commit_a)
155        undefined_a, _ = check_symbols(args.ignore)
156
157        # get undefined items for the commit
158        reset(commit_b)
159        undefined_b, defined = check_symbols(args.ignore)
160
161        # report cases that are present for the commit but not before
162        for symbol in sorted(undefined_b):
163            # symbol has not been undefined before
164            if symbol not in undefined_a:
165                files = sorted(undefined_b.get(symbol))
166                undefined[symbol] = files
167            # check if there are new files that reference the undefined symbol
168            else:
169                files = sorted(undefined_b.get(symbol) -
170                               undefined_a.get(symbol))
171                if files:
172                    undefined[symbol] = files
173
174        # reset to head
175        reset(head)
176
177    # default to check the entire tree
178    else:
179        undefined, defined = check_symbols(args.ignore)
180
181    # now print the output
182    for symbol in sorted(undefined):
183        print(red(symbol))
184
185        files = sorted(undefined.get(symbol))
186        print("%s: %s" % (yel("Referencing files"), ", ".join(files)))
187
188        sims = find_sims(symbol, args.ignore, defined)
189        sims_out = yel("Similar symbols")
190        if sims:
191            print("%s: %s" % (sims_out, ', '.join(sims)))
192        else:
193            print("%s: %s" % (sims_out, "no similar symbols found"))
194
195        if args.find:
196            print("%s:" % yel("Commits changing symbol"))
197            commits = find_commits(symbol, args.diff)
198            if commits:
199                for commit in commits:
200                    commit = commit.split(" ", 1)
201                    print("\t- %s (\"%s\")" % (yel(commit[0]), commit[1]))
202            else:
203                print("\t- no commit found")
204        print()  # new line
205
206
207def reset(commit):
208    """Reset current git tree to %commit."""
209    execute(["git", "reset", "--hard", commit])
210
211
212def yel(string):
213    """
214    Color %string yellow.
215    """
216    return "\033[33m%s\033[0m" % string if COLOR else string
217
218
219def red(string):
220    """
221    Color %string red.
222    """
223    return "\033[31m%s\033[0m" % string if COLOR else string
224
225
226def execute(cmd):
227    """Execute %cmd and return stdout.  Exit in case of error."""
228    try:
229        stdout = subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=False)
230        stdout = stdout.decode(errors='replace')
231    except subprocess.CalledProcessError as fail:
232        exit(fail)
233    return stdout
234
235
236def find_commits(symbol, diff):
237    """Find commits changing %symbol in the given range of %diff."""
238    commits = execute(["git", "log", "--pretty=oneline",
239                       "--abbrev-commit", "-G",
240                       symbol, diff])
241    return [x for x in commits.split("\n") if x]
242
243
244def tree_is_dirty():
245    """Return true if the current working tree is dirty (i.e., if any file has
246    been added, deleted, modified, renamed or copied but not committed)."""
247    stdout = execute(["git", "status", "--porcelain"])
248    for line in stdout:
249        if re.findall(r"[URMADC]{1}", line[:2]):
250            return True
251    return False
252
253
254def get_head():
255    """Return commit hash of current HEAD."""
256    stdout = execute(["git", "rev-parse", "HEAD"])
257    return stdout.strip('\n')
258
259
260def partition(lst, size):
261    """Partition list @lst into eveni-sized lists of size @size."""
262    return [lst[i::size] for i in range(size)]
263
264
265def init_worker():
266    """Set signal handler to ignore SIGINT."""
267    signal.signal(signal.SIGINT, signal.SIG_IGN)
268
269
270def find_sims(symbol, ignore, defined=[]):
271    """Return a list of max. ten Kconfig symbols that are string-similar to
272    @symbol."""
273    if defined:
274        return difflib.get_close_matches(symbol, set(defined), 10)
275
276    pool = Pool(cpu_count(), init_worker)
277    kfiles = []
278    for gitfile in get_files():
279        if REGEX_FILE_KCONFIG.match(gitfile):
280            kfiles.append(gitfile)
281
282    arglist = []
283    for part in partition(kfiles, cpu_count()):
284        arglist.append((part, ignore))
285
286    for res in pool.map(parse_kconfig_files, arglist):
287        defined.extend(res[0])
288
289    return difflib.get_close_matches(symbol, set(defined), 10)
290
291
292def get_files():
293    """Return a list of all files in the current git directory."""
294    # use 'git ls-files' to get the worklist
295    stdout = execute(["git", "ls-files"])
296    if len(stdout) > 0 and stdout[-1] == "\n":
297        stdout = stdout[:-1]
298
299    files = []
300    for gitfile in stdout.rsplit("\n"):
301        if ".git" in gitfile or "ChangeLog" in gitfile or      \
302                ".log" in gitfile or os.path.isdir(gitfile) or \
303                gitfile.startswith("tools/"):
304            continue
305        files.append(gitfile)
306    return files
307
308
309def check_symbols(ignore):
310    """Find undefined Kconfig symbols and return a dict with the symbol as key
311    and a list of referencing files as value.  Files matching %ignore are not
312    checked for undefined symbols."""
313    pool = Pool(cpu_count(), init_worker)
314    try:
315        return check_symbols_helper(pool, ignore)
316    except KeyboardInterrupt:
317        pool.terminate()
318        pool.join()
319        sys.exit(1)
320
321
322def check_symbols_helper(pool, ignore):
323    """Helper method for check_symbols().  Used to catch keyboard interrupts in
324    check_symbols() in order to properly terminate running worker processes."""
325    source_files = []
326    kconfig_files = []
327    defined_symbols = []
328    referenced_symbols = dict()  # {file: [symbols]}
329
330    for gitfile in get_files():
331        if REGEX_FILE_KCONFIG.match(gitfile):
332            kconfig_files.append(gitfile)
333        else:
334            if ignore and re.match(ignore, gitfile):
335                continue
336            # add source files that do not match the ignore pattern
337            source_files.append(gitfile)
338
339    # parse source files
340    arglist = partition(source_files, cpu_count())
341    for res in pool.map(parse_source_files, arglist):
342        referenced_symbols.update(res)
343
344    # parse kconfig files
345    arglist = []
346    for part in partition(kconfig_files, cpu_count()):
347        arglist.append((part, ignore))
348    for res in pool.map(parse_kconfig_files, arglist):
349        defined_symbols.extend(res[0])
350        referenced_symbols.update(res[1])
351    defined_symbols = set(defined_symbols)
352
353    # inverse mapping of referenced_symbols to dict(symbol: [files])
354    inv_map = dict()
355    for _file, symbols in referenced_symbols.items():
356        for symbol in symbols:
357            inv_map[symbol] = inv_map.get(symbol, set())
358            inv_map[symbol].add(_file)
359    referenced_symbols = inv_map
360
361    undefined = {}  # {symbol: [files]}
362    for symbol in sorted(referenced_symbols):
363        # filter some false positives
364        if symbol == "FOO" or symbol == "BAR" or \
365                symbol == "FOO_BAR" or symbol == "XXX":
366            continue
367        if symbol not in defined_symbols:
368            if symbol.endswith("_MODULE"):
369                # avoid false positives for kernel modules
370                if symbol[:-len("_MODULE")] in defined_symbols:
371                    continue
372            undefined[symbol] = referenced_symbols.get(symbol)
373    return undefined, defined_symbols
374
375
376def parse_source_files(source_files):
377    """Parse each source file in @source_files and return dictionary with source
378    files as keys and lists of references Kconfig symbols as values."""
379    referenced_symbols = dict()
380    for sfile in source_files:
381        referenced_symbols[sfile] = parse_source_file(sfile)
382    return referenced_symbols
383
384
385def parse_source_file(sfile):
386    """Parse @sfile and return a list of referenced Kconfig symbols."""
387    lines = []
388    references = []
389
390    if not os.path.exists(sfile):
391        return references
392
393    with open(sfile, "r", encoding='utf-8', errors='replace') as stream:
394        lines = stream.readlines()
395
396    for line in lines:
397        if "CONFIG_" not in line:
398            continue
399        symbols = REGEX_SOURCE_SYMBOL.findall(line)
400        for symbol in symbols:
401            if not REGEX_FILTER_SYMBOLS.search(symbol):
402                continue
403            references.append(symbol)
404
405    return references
406
407
408def get_symbols_in_line(line):
409    """Return mentioned Kconfig symbols in @line."""
410    return REGEX_SYMBOL.findall(line)
411
412
413def parse_kconfig_files(args):
414    """Parse kconfig files and return tuple of defined and references Kconfig
415    symbols.  Note, @args is a tuple of a list of files and the @ignore
416    pattern."""
417    kconfig_files = args[0]
418    ignore = args[1]
419    defined_symbols = []
420    referenced_symbols = dict()
421
422    for kfile in kconfig_files:
423        defined, references = parse_kconfig_file(kfile)
424        defined_symbols.extend(defined)
425        if ignore and re.match(ignore, kfile):
426            # do not collect references for files that match the ignore pattern
427            continue
428        referenced_symbols[kfile] = references
429    return (defined_symbols, referenced_symbols)
430
431
432def parse_kconfig_file(kfile):
433    """Parse @kfile and update symbol definitions and references."""
434    lines = []
435    defined = []
436    references = []
437
438    if not os.path.exists(kfile):
439        return defined, references
440
441    with open(kfile, "r", encoding='utf-8', errors='replace') as stream:
442        lines = stream.readlines()
443
444    for i in range(len(lines)):
445        line = lines[i]
446        line = line.strip('\n')
447        line = line.split("#")[0]  # ignore comments
448
449        if REGEX_KCONFIG_DEF.match(line):
450            symbol_def = REGEX_KCONFIG_DEF.findall(line)
451            defined.append(symbol_def[0])
452        elif REGEX_KCONFIG_STMT.match(line):
453            line = REGEX_QUOTES.sub("", line)
454            symbols = get_symbols_in_line(line)
455            # multi-line statements
456            while line.endswith("\\"):
457                i += 1
458                line = lines[i]
459                line = line.strip('\n')
460                symbols.extend(get_symbols_in_line(line))
461            for symbol in set(symbols):
462                if REGEX_NUMERIC.match(symbol):
463                    # ignore numeric values
464                    continue
465                references.append(symbol)
466
467    return defined, references
468
469
470def main():
471    try:
472        print_undefined_symbols()
473    except BrokenPipeError:
474        # Python flushes standard streams on exit; redirect remaining output
475        # to devnull to avoid another BrokenPipeError at shutdown
476        devnull = os.open(os.devnull, os.O_WRONLY)
477        os.dup2(devnull, sys.stdout.fileno())
478        sys.exit(1)  # Python exits with error code 1 on EPIPE
479
480
481if __name__ == "__main__":
482    main()
483