cppcheck/addons/cert.py

80 lines
2.7 KiB
Python

#/usr/bin/python
#
# Cert: Some extra CERT checkers
#
# Cppcheck itself handles many CERT rules. Cppcheck warns when there is undefined behaviour.
#
# Example usage of this addon (scan a sourcefile main.cpp)
# cppcheck --dump main.cpp
# python cert.py main.cpp.dump
import cppcheckdata
import sys
import re
def reportError(token, severity, msg):
sys.stderr.write('[' + token.file + ':' + str(token.linenr) + '] (' + severity + ') cert.py: ' + msg + '\n')
def isUnpackedStruct(var):
decl = var.typeStartToken
while decl and decl.isName:
if decl.str == 'struct':
structScope = decl.next.typeScope
if structScope:
linenr = int(structScope.classStart.linenr)
for line in open(structScope.classStart.file):
linenr = linenr - 1
if linenr == 0:
return True
if re.match(r'#pragma\s+pack\s*\(',line):
return False
break
decl = decl.next
return False
def isLocalUnpackedStruct(arg):
if arg and arg.str == '&' and not arg.astOperand2:
arg = arg.astOperand1
return arg and arg.variable and (arg.variable.isLocal or arg.variable.isArgument) and isUnpackedStruct(arg.variable)
def isBitwiseOp(token):
return token and (token.str in ['&', '|', '^'])
def isComparisonOp(token):
return token and (token.str in ['==', '!=', '>', '>=', '<', '<='])
# EXP42-C
# do not compare padding data
def exp42(data):
for token in data.tokenlist:
if token.str != '(' or not token.astOperand1:
continue
arg1 = None
arg2 = None
if token.astOperand2 and token.astOperand2.str == ',':
if token.astOperand2.astOperand1 and token.astOperand2.astOperand1.str == ',':
arg1 = token.astOperand2.astOperand1.astOperand1
arg2 = token.astOperand2.astOperand1.astOperand2
if token.astOperand1.str == 'memcmp' and (isLocalUnpackedStruct(arg1) or isLocalUnpackedStruct(arg2)):
reportError(token, 'style', 'EXP42-C Comparison of struct padding data (fix either by packing the struct using \'#pragma pack\' or by rewriting the comparison)')
# EXP46-C
# Do not use a bitwise operator with a Boolean-like operand
# int x = (a == b) & c;
def exp46(data):
for token in data.tokenlist:
if isBitwiseOp(token) and (isComparisonOp(token.astOperand1) or isComparisonOp(token.astOperand2)):
reportError(token, 'style', 'EXP46-C Bitwise operator is used with a Boolean-like operand')
for arg in sys.argv[1:]:
print('Checking ' + arg + '...')
data = cppcheckdata.parsedump(arg)
exp42(data)
exp46(data)