walkero
/
cppcheck
1
0
Fork 0
Code Issues Pull Requests Projects Releases 1 Wiki Activity

checkIntegerOverflow: check all calculations, not only in function bodies

This commit is contained in:
Daniel Marjamäki 2017-09-19 14:43:48 +02:00
parent 6bc0df2908
commit cac7146cac
2 changed files with 20 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
lib/checktype.cpp
View File

@ -145,32 +145,27 @@ void CheckType::checkIntegerOverflow()
// max int value according to platform settings.
const MathLib::bigint maxint = (1LL << (_settings->int_bit - 1)) - 1;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
const std::size_t functions = symbolDatabase->functionScopes.size();
for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symbolDatabase->functionScopes[i];
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
if (!tok->isArithmeticalOp())
continue;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (!tok->isArithmeticalOp())
continue;
// is result signed integer?
const ValueType *vt = tok->valueType();
if (!vt || vt->type != ValueType::Type::INT || vt->sign != ValueType::Sign::SIGNED)
continue;
// is result signed integer?
const ValueType *vt = tok->valueType();
if (!vt || vt->type != ValueType::Type::INT || vt->sign != ValueType::Sign::SIGNED)
continue;
// is there a overflow result value
const ValueFlow::Value *value = tok->getValueGE(maxint + 1, _settings);
if (!value)
value = tok->getValueLE(-maxint - 2, _settings);
if (!value || !_settings->isEnabled(value,false))
continue;
// is there a overflow result value
const ValueFlow::Value *value = tok->getValueGE(maxint + 1, _settings);
if (!value)
value = tok->getValueLE(-maxint - 2, _settings);
if (!value || !_settings->isEnabled(value,false))
continue;
// For left shift, it's common practice to shift into the sign bit
if (tok->str() == "<<" && value->intvalue > 0 && value->intvalue < (1LL << _settings->int_bit))
continue;
// For left shift, it's common practice to shift into the sign bit
if (tok->str() == "<<" && value->intvalue > 0 && value->intvalue < (1LL << _settings->int_bit))
continue;
integerOverflowError(tok, *value);
}
integerOverflowError(tok, *value);
}
}

3
test/testtype.cpp
View File

@ -110,6 +110,9 @@ private:
settings.platform(Settings::Unix32);
settings.addEnabled("warning");
check("x = (int)0x10000 * (int)0x10000;", &settings);
ASSERT_EQUALS("[test.cpp:1]: (error) Signed integer overflow for expression '(int)65536*(int)65536'.\n", errout.str());
check("void foo() {\n"
" int intmax = 0x7fffffff;\n"
" return intmax + 1;\n"