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checkIntegerOverflow: handle long and long long also

This commit is contained in:
Daniel Marjamäki 2017-09-19 19:14:29 +02:00
parent 78ae435a94
commit f6e30eee19
2 changed files with 23 additions and 7 deletions
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27
lib/checktype.cpp
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@ -142,27 +142,40 @@ void CheckType::checkIntegerOverflow()
if (_settings->platformType == Settings::Unspecified || _settings->int_bit >= 64)
return;
// max int value according to platform settings.
const MathLib::bigint maxint = (1LL << (_settings->int_bit - 1)) - 1;
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)
if (!vt || !vt->isIntegral() || vt->sign != ValueType::Sign::SIGNED)
continue;
unsigned int bits;
if (vt->type == ValueType::Type::INT)
bits = _settings->int_bit;
else if (vt->type == ValueType::Type::LONG)
bits = _settings->long_bit;
else if (vt->type == ValueType::Type::LONGLONG)
bits = _settings->long_long_bit;
else
continue;
if (bits >= 64)
continue;
// max value according to platform settings.
const MathLib::bigint maxvalue = (1LL << (bits - 1)) - 1;
// is there a overflow result value
const ValueFlow::Value *value = tok->getValueGE(maxint + 1, _settings);
const ValueFlow::Value *value = tok->getValueGE(maxvalue + 1, _settings);
if (!value)
value = tok->getValueLE(-maxint - 2, _settings);
value = tok->getValueLE(-maxvalue - 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))
if (tok->str() == "<<" && value->intvalue > 0 && value->intvalue < (1LL << bits))
continue;
integerOverflowError(tok, *value);

3
test/testtype.cpp
View File

@ -113,6 +113,9 @@ private:
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("x = (long)0x10000 * (long)0x10000;", &settings);
ASSERT_EQUALS("[test.cpp:1]: (error) Signed integer overflow for expression '(long)65536*(long)65536'.\n", errout.str());
check("void foo() {\n"
" int intmax = 0x7fffffff;\n"
" return intmax + 1;\n"