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Fix 10289: ValueFlow; Wrong known value 'size_t - uint16_t > 0' (#3273)

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Paul Fultz II 2021-05-24 01:28:21 -05:00 committed by GitHub
parent 8ad0905e3b
commit ab50a75d8a
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2 changed files with 67 additions and 48 deletions
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107
lib/valueflow.cpp
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@ -431,6 +431,19 @@ static T calculate(const std::string& s, const T& x, const T& y)
/** Set token value for cast */
static void setTokenValueCast(Token *parent, const ValueType &valueType, const ValueFlow::Value &value, const Settings *settings);
static bool isCompatibleValues(const ValueFlow::Value& value1, const ValueFlow::Value& value2)
{
if (value1.isKnown() || value2.isKnown())
return true;
if (value1.isImpossible() || value2.isImpossible())
return false;
if (value1.varId == 0 || value2.varId == 0)
return true;
if (value1.varId == value2.varId && value1.varvalue == value2.varvalue && value1.isIntValue() && value2.isIntValue())
return true;
return false;
}
/** set ValueFlow value and perform calculations if possible */
static void setTokenValue(Token* tok, const ValueFlow::Value &value, const Settings *settings)
{
@ -652,56 +665,54 @@ static void setTokenValue(Token* tok, const ValueFlow::Value &value, const Setti
continue;
if (value1.isIteratorValue() && value2.isIteratorValue())
continue;
if (value1.isKnown() || value2.isKnown() || value1.varId == 0 || value2.varId == 0 ||
(value1.varId == value2.varId && value1.varvalue == value2.varvalue && value1.isIntValue() &&
value2.isIntValue())) {
ValueFlow::Value result(0);
combineValueProperties(value1, value2, &result);
const double floatValue1 = value1.isIntValue() ? value1.intvalue : value1.floatValue;
const double floatValue2 = value2.isIntValue() ? value2.intvalue : value2.floatValue;
const bool isFloat = value1.isFloatValue() || value2.isFloatValue();
if (isFloat && Token::Match(parent, "&|^|%|<<|>>|%or%"))
if (!isCompatibleValues(value1, value2))
continue;
ValueFlow::Value result(0);
combineValueProperties(value1, value2, &result);
const double floatValue1 = value1.isIntValue() ? value1.intvalue : value1.floatValue;
const double floatValue2 = value2.isIntValue() ? value2.intvalue : value2.floatValue;
const bool isFloat = value1.isFloatValue() || value2.isFloatValue();
if (isFloat && Token::Match(parent, "&|^|%|<<|>>|%or%"))
continue;
if (Token::Match(parent, "<<|>>") &&
!(value1.intvalue >= 0 && value2.intvalue >= 0 && value2.intvalue < MathLib::bigint_bits))
continue;
if (Token::Match(parent, "/|%") && isZero<double>(floatValue2))
continue;
if (Token::Match(parent, "==|!=")) {
if ((value1.isIntValue() && value2.isTokValue()) || (value1.isTokValue() && value2.isIntValue())) {
if (parent->str() == "==")
result.intvalue = 0;
else if (parent->str() == "!=")
result.intvalue = 1;
} else if (value1.isIntValue() && value2.isIntValue()) {
result.intvalue = calculate(parent->str(), value1.intvalue, value2.intvalue);
} else {
continue;
if (Token::Match(parent, "<<|>>") &&
!(value1.intvalue >= 0 && value2.intvalue >= 0 && value2.intvalue < MathLib::bigint_bits))
continue;
if (Token::Match(parent, "/|%") && isZero<double>(floatValue2))
continue;
if (Token::Match(parent, "==|!=")) {
if ((value1.isIntValue() && value2.isTokValue()) || (value1.isTokValue() && value2.isIntValue())) {
if (parent->str() == "==")
result.intvalue = 0;
else if (parent->str() == "!=")
result.intvalue = 1;
} else if (value1.isIntValue() && value2.isIntValue()) {
result.intvalue = calculate(parent->str(), value1.intvalue, value2.intvalue);
} else {
continue;
}
setTokenValue(parent, result, settings);
} else if (Token::Match(parent, "%comp%")) {
if (!isFloat && !value1.isIntValue() && !value2.isIntValue())
continue;
if (isFloat)
result.intvalue = calculate(parent->str(), floatValue1, floatValue2);
else
result.intvalue = calculate(parent->str(), value1.intvalue, value2.intvalue);
setTokenValue(parent, result, settings);
} else if (Token::Match(parent, "%op%")) {
if (value1.isTokValue() || value2.isTokValue())
break;
if (isFloat) {
result.valueType = ValueFlow::Value::ValueType::FLOAT;
result.floatValue = calculate(parent->str(), floatValue1, floatValue2);
} else {
result.intvalue = calculate(parent->str(), value1.intvalue, value2.intvalue);
}
// If the bound comes from the second value then invert the bound when subtracting
if (Token::simpleMatch(parent, "-") && value2.bound == result.bound &&
value2.bound != ValueFlow::Value::Bound::Point)
result.invertBound();
setTokenValue(parent, result, settings);
}
setTokenValue(parent, result, settings);
} else if (Token::Match(parent, "%comp%")) {
if (!isFloat && !value1.isIntValue() && !value2.isIntValue())
continue;
if (isFloat)
result.intvalue = calculate(parent->str(), floatValue1, floatValue2);
else
result.intvalue = calculate(parent->str(), value1.intvalue, value2.intvalue);
setTokenValue(parent, result, settings);
} else if (Token::Match(parent, "%op%")) {
if (value1.isTokValue() || value2.isTokValue())
break;
if (isFloat) {
result.valueType = ValueFlow::Value::ValueType::FLOAT;
result.floatValue = calculate(parent->str(), floatValue1, floatValue2);
} else {
result.intvalue = calculate(parent->str(), value1.intvalue, value2.intvalue);
}
// If the bound comes from the second value then invert the bound when subtracting
if (Token::simpleMatch(parent, "-") && value2.bound == result.bound &&
value2.bound != ValueFlow::Value::Bound::Point)
result.invertBound();
setTokenValue(parent, result, settings);
}
}
}

8
test/testvalueflow.cpp
View File

@ -5629,6 +5629,14 @@ private:
" return x;\n"
"}\n";
ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, -1));
code = "size_t g();\n"
"auto f(uint16_t j) {\n"
" auto x = g() - j;\n"
" return x;\n"
"}\n";
ASSERT_EQUALS(false, testValueOfXImpossible(code, 4U, 0));
ASSERT_EQUALS(true, testValueOfXImpossible(code, 4U, -1));
}
};