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#!/usr/bin/env python3
#
# Copyright (c) 2018 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
#
# Lint format strings: This program checks that the number of arguments passed
# to a variadic format string function matches the number of format specifiers
# in the format string.
import argparse
import re
import sys
FALSE_POSITIVES = [
("src/dbwrapper.cpp", "vsnprintf(p, limit - p, format, backup_ap)"),
("src/index/base.cpp", "FatalError(const char* fmt, const Args&... args)"),
("src/netbase.cpp", "LogConnectFailure(bool manual_connection, const char* fmt, const Args&... args)"),
("src/util.cpp", "strprintf(_(COPYRIGHT_HOLDERS), _(COPYRIGHT_HOLDERS_SUBSTITUTION))"),
("src/util.cpp", "strprintf(COPYRIGHT_HOLDERS, COPYRIGHT_HOLDERS_SUBSTITUTION)"),
("src/wallet/wallet.h", "WalletLogPrintf(std::string fmt, Params... parameters)"),
("src/wallet/wallet.h", "LogPrintf((\"%s \" + fmt).c_str(), GetDisplayName(), parameters...)"),
]
def parse_function_calls(function_name, source_code):
"""Return an array with all calls to function function_name in string source_code.
Preprocessor directives and C++ style comments ("//") in source_code are removed.
>>> len(parse_function_calls("foo", "foo();bar();foo();bar();"))
2
>>> parse_function_calls("foo", "foo(1);bar(1);foo(2);bar(2);")[0].startswith("foo(1);")
True
>>> parse_function_calls("foo", "foo(1);bar(1);foo(2);bar(2);")[1].startswith("foo(2);")
True
>>> len(parse_function_calls("foo", "foo();bar();// foo();bar();"))
1
>>> len(parse_function_calls("foo", "#define FOO foo();"))
0
"""
assert(type(function_name) is str and type(source_code) is str and function_name)
lines = [re.sub("// .*", " ", line).strip()
for line in source_code.split("\n")
if not line.strip().startswith("#")]
return re.findall(r"[^a-zA-Z_](?=({}\(.*).*)".format(function_name), " " + " ".join(lines))
def normalize(s):
"""Return a normalized version of string s with newlines, tabs and C style comments ("/* ... */")
replaced with spaces. Multiple spaces are replaced with a single space.
>>> normalize(" /* nothing */ foo\tfoo /* bar */ foo ")
'foo foo foo'
"""
assert(type(s) is str)
s = s.replace("\n", " ")
s = s.replace("\t", " ")
s = re.sub("/\*.*?\*/", " ", s)
s = re.sub(" {2,}", " ", s)
return s.strip()
ESCAPE_MAP = {
r"\n": "[escaped-newline]",
r"\t": "[escaped-tab]",
r'\"': "[escaped-quote]",
}
def escape(s):
"""Return the escaped version of string s with "\\\"", "\\n" and "\\t" escaped as
"[escaped-backslash]", "[escaped-newline]" and "[escaped-tab]".
>>> unescape(escape("foo")) == "foo"
True
>>> escape(r'foo \\t foo \\n foo \\\\ foo \\ foo \\"bar\\"')
'foo [escaped-tab] foo [escaped-newline] foo \\\\\\\\ foo \\\\ foo [escaped-quote]bar[escaped-quote]'
"""
assert(type(s) is str)
for raw_value, escaped_value in ESCAPE_MAP.items():
s = s.replace(raw_value, escaped_value)
return s
def unescape(s):
"""Return the unescaped version of escaped string s.
Reverses the replacements made in function escape(s).
>>> unescape(escape("bar"))
'bar'
>>> unescape("foo [escaped-tab] foo [escaped-newline] foo \\\\\\\\ foo \\\\ foo [escaped-quote]bar[escaped-quote]")
'foo \\\\t foo \\\\n foo \\\\\\\\ foo \\\\ foo \\\\"bar\\\\"'
"""
assert(type(s) is str)
for raw_value, escaped_value in ESCAPE_MAP.items():
s = s.replace(escaped_value, raw_value)
return s
def parse_function_call_and_arguments(function_name, function_call):
"""Split string function_call into an array of strings consisting of:
* the string function_call followed by "("
* the function call argument #1
* ...
* the function call argument #n
* a trailing ");"
The strings returned are in escaped form. See escape(...).
>>> parse_function_call_and_arguments("foo", 'foo("%s", "foo");')
['foo(', '"%s",', ' "foo"', ')']
>>> parse_function_call_and_arguments("foo", 'foo("%s", "foo");')
['foo(', '"%s",', ' "foo"', ')']
>>> parse_function_call_and_arguments("foo", 'foo("%s %s", "foo", "bar");')
['foo(', '"%s %s",', ' "foo",', ' "bar"', ')']
>>> parse_function_call_and_arguments("fooprintf", 'fooprintf("%050d", i);')
['fooprintf(', '"%050d",', ' i', ')']
>>> parse_function_call_and_arguments("foo", 'foo(bar(foobar(barfoo("foo"))), foobar); barfoo')
['foo(', 'bar(foobar(barfoo("foo"))),', ' foobar', ')']
>>> parse_function_call_and_arguments("foo", "foo()")
['foo(', '', ')']
>>> parse_function_call_and_arguments("foo", "foo(123)")
['foo(', '123', ')']
>>> parse_function_call_and_arguments("foo", 'foo("foo")')
['foo(', '"foo"', ')']
"""
assert(type(function_name) is str and type(function_call) is str and function_name)
remaining = normalize(escape(function_call))
expected_function_call = "{}(".format(function_name)
assert(remaining.startswith(expected_function_call))
parts = [expected_function_call]
remaining = remaining[len(expected_function_call):]
open_parentheses = 1
in_string = False
parts.append("")
for char in remaining:
parts.append(parts.pop() + char)
if char == "\"":
in_string = not in_string
continue
if in_string:
continue
if char == "(":
open_parentheses += 1
continue
if char == ")":
open_parentheses -= 1
if open_parentheses > 1:
continue
if open_parentheses == 0:
parts.append(parts.pop()[:-1])
parts.append(char)
break
if char == ",":
parts.append("")
return parts
def parse_string_content(argument):
"""Return the text within quotes in string argument.
>>> parse_string_content('1 "foo %d bar" 2')
'foo %d bar'
>>> parse_string_content('1 foobar 2')
''
>>> parse_string_content('1 "bar" 2')
'bar'
>>> parse_string_content('1 "foo" 2 "bar" 3')
'foobar'
>>> parse_string_content('1 "foo" 2 " " "bar" 3')
'foo bar'
>>> parse_string_content('""')
''
>>> parse_string_content('')
''
>>> parse_string_content('1 2 3')
''
"""
assert(type(argument) is str)
string_content = ""
in_string = False
for char in normalize(escape(argument)):
if char == "\"":
in_string = not in_string
elif in_string:
string_content += char
return string_content
def count_format_specifiers(format_string):
"""Return the number of format specifiers in string format_string.
>>> count_format_specifiers("foo bar foo")
0
>>> count_format_specifiers("foo %d bar foo")
1
>>> count_format_specifiers("foo %d bar %i foo")
2
>>> count_format_specifiers("foo %d bar %i foo %% foo")
2
>>> count_format_specifiers("foo %d bar %i foo %% foo %d foo")
3
>>> count_format_specifiers("foo %d bar %i foo %% foo %*d foo")
4
"""
assert(type(format_string) is str)
n = 0
in_specifier = False
for i, char in enumerate(format_string):
if format_string[i - 1:i + 1] == "%%" or format_string[i:i + 2] == "%%":
pass
elif char == "%":
in_specifier = True
n += 1
elif char in "aAcdeEfFgGinopsuxX":
in_specifier = False
elif in_specifier and char == "*":
n += 1
return n
def main():
parser = argparse.ArgumentParser(description="This program checks that the number of arguments passed "
"to a variadic format string function matches the number of format "
"specifiers in the format string.")
parser.add_argument("--skip-arguments", type=int, help="number of arguments before the format string "
"argument (e.g. 1 in the case of fprintf)", default=0)
parser.add_argument("function_name", help="function name (e.g. fprintf)", default=None)
parser.add_argument("file", type=argparse.FileType("r", encoding="utf-8"), nargs="*", help="C++ source code file (e.g. foo.cpp)")
args = parser.parse_args()
exit_code = 0
for f in args.file:
for function_call_str in parse_function_calls(args.function_name, f.read()):
parts = parse_function_call_and_arguments(args.function_name, function_call_str)
relevant_function_call_str = unescape("".join(parts))[:512]
if (f.name, relevant_function_call_str) in FALSE_POSITIVES:
continue
if len(parts) < 3 + args.skip_arguments:
exit_code = 1
print("{}: Could not parse function call string \"{}(...)\": {}".format(f.name, args.function_name, relevant_function_call_str))
continue
argument_count = len(parts) - 3 - args.skip_arguments
format_str = parse_string_content(parts[1 + args.skip_arguments])
format_specifier_count = count_format_specifiers(format_str)
if format_specifier_count != argument_count:
exit_code = 1
print("{}: Expected {} argument(s) after format string but found {} argument(s): {}".format(f.name, format_specifier_count, argument_count, relevant_function_call_str))
continue
sys.exit(exit_code)
if __name__ == "__main__":
main()
|
