cppcheck/lib/valueflow.h

518 lines
17 KiB
C++

/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2021 Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
//---------------------------------------------------------------------------
#ifndef valueflowH
#define valueflowH
//---------------------------------------------------------------------------
#include "astutils.h"
#include "config.h"
#include "mathlib.h"
#include "utils.h"
#include <cassert>
#include <functional>
#include <list>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
class ErrorLogger;
struct InferModel;
class Settings;
class SymbolDatabase;
class Token;
class TokenList;
class ValueType;
class Variable;
template<class T>
class ValuePtr;
namespace ValueFlow {
struct increment {
template<class T>
void operator()(T& x) const {
x++;
}
};
struct decrement {
template<class T>
void operator()(T& x) const {
x--;
}
};
struct less {
template<class T, class U>
bool operator()(const T& x, const U& y) const {
return x < y;
}
};
struct adjacent {
template<class T, class U>
bool operator()(const T& x, const U& y) const {
return std::abs(x - y) == 1;
}
};
struct equalVisitor {
template<class T, class U>
void operator()(bool& result, T x, U y) const {
result = !(x > y || x < y);
}
};
class CPPCHECKLIB Value {
public:
typedef std::pair<const Token *, std::string> ErrorPathItem;
typedef std::list<ErrorPathItem> ErrorPath;
enum class Bound { Upper, Lower, Point };
explicit Value(long long val = 0, Bound b = Bound::Point)
: valueType(ValueType::INT),
bound(b),
intvalue(val),
tokvalue(nullptr),
floatValue(0.0),
moveKind(MoveKind::NonMovedVariable),
varvalue(val),
condition(nullptr),
varId(0U),
safe(false),
conditional(false),
macro(false),
defaultArg(false),
indirect(0),
path(0),
wideintvalue(val),
subexpressions(),
lifetimeKind(LifetimeKind::Object),
lifetimeScope(LifetimeScope::Local),
valueKind(ValueKind::Possible)
{}
Value(const Token* c, long long val, Bound b = Bound::Point);
static Value unknown();
bool equalValue(const ValueFlow::Value& rhs) const {
if (valueType != rhs.valueType)
return false;
switch (valueType) {
case ValueType::INT:
case ValueType::CONTAINER_SIZE:
case ValueType::BUFFER_SIZE:
case ValueType::ITERATOR_START:
case ValueType::ITERATOR_END:
if (intvalue != rhs.intvalue)
return false;
break;
case ValueType::TOK:
if (tokvalue != rhs.tokvalue)
return false;
break;
case ValueType::FLOAT:
// TODO: Write some better comparison
if (floatValue > rhs.floatValue || floatValue < rhs.floatValue)
return false;
break;
case ValueType::MOVED:
if (moveKind != rhs.moveKind)
return false;
break;
case ValueType::UNINIT:
break;
case ValueType::LIFETIME:
if (tokvalue != rhs.tokvalue)
return false;
break;
case ValueType::SYMBOLIC:
if (!sameToken(tokvalue, rhs.tokvalue))
return false;
if (intvalue != rhs.intvalue)
return false;
break;
}
return true;
}
template<class T, class F>
static void visitValue(T& self, F f) {
switch (self.valueType) {
case ValueType::INT:
case ValueType::SYMBOLIC:
case ValueType::BUFFER_SIZE:
case ValueType::CONTAINER_SIZE:
case ValueType::ITERATOR_START:
case ValueType::ITERATOR_END: {
f(self.intvalue);
break;
}
case ValueType::FLOAT: {
f(self.floatValue);
break;
}
case ValueType::UNINIT:
case ValueType::TOK:
case ValueType::LIFETIME:
case ValueType::MOVED:
break;
}
}
struct compareVisitor {
struct innerVisitor {
template<class Compare, class T, class U>
void operator()(bool& result, Compare compare, T x, U y) const {
result = compare(x, y);
}
};
template<class Compare, class T>
void operator()(bool& result, const Value& rhs, Compare compare, T x) const {
visitValue(rhs,
std::bind(innerVisitor{}, std::ref(result), std::move(compare), x, std::placeholders::_1));
}
};
template<class Compare>
bool compareValue(const Value& rhs, Compare compare) const {
assert((!this->isSymbolicValue() && !rhs.isSymbolicValue()) ||
(this->valueType == rhs.valueType && sameToken(this->tokvalue, rhs.tokvalue)));
bool result = false;
visitValue(
*this,
std::bind(compareVisitor{}, std::ref(result), std::ref(rhs), std::move(compare), std::placeholders::_1));
return result;
}
bool operator==(const Value &rhs) const {
if (!equalValue(rhs))
return false;
return varvalue == rhs.varvalue &&
condition == rhs.condition &&
varId == rhs.varId &&
conditional == rhs.conditional &&
defaultArg == rhs.defaultArg &&
indirect == rhs.indirect &&
valueKind == rhs.valueKind;
}
bool operator!=(const Value &rhs) const {
return !(*this == rhs);
}
template<class T, REQUIRES("T must be an arithmetic type", std::is_arithmetic<T> )>
bool equalTo(const T& x) const {
bool result = false;
visitValue(*this, std::bind(equalVisitor{}, std::ref(result), x, std::placeholders::_1));
return result;
}
void decreaseRange() {
if (bound == Bound::Lower)
visitValue(*this, increment{});
else if (bound == Bound::Upper)
visitValue(*this, decrement{});
}
void invertBound() {
if (bound == Bound::Lower)
bound = Bound::Upper;
else if (bound == Bound::Upper)
bound = Bound::Lower;
}
void invertRange() {
invertBound();
decreaseRange();
}
void assumeCondition(const Token* tok);
std::string infoString() const;
enum class ValueType {
INT,
TOK,
FLOAT,
MOVED,
UNINIT,
CONTAINER_SIZE,
LIFETIME,
BUFFER_SIZE,
ITERATOR_START,
ITERATOR_END,
SYMBOLIC
} valueType;
bool isIntValue() const {
return valueType == ValueType::INT;
}
bool isTokValue() const {
return valueType == ValueType::TOK;
}
bool isFloatValue() const {
return valueType == ValueType::FLOAT;
}
bool isMovedValue() const {
return valueType == ValueType::MOVED;
}
bool isUninitValue() const {
return valueType == ValueType::UNINIT;
}
bool isContainerSizeValue() const {
return valueType == ValueType::CONTAINER_SIZE;
}
bool isLifetimeValue() const {
return valueType == ValueType::LIFETIME;
}
bool isBufferSizeValue() const {
return valueType == ValueType::BUFFER_SIZE;
}
bool isIteratorValue() const {
return valueType == ValueType::ITERATOR_START || valueType == ValueType::ITERATOR_END;
}
bool isIteratorStartValue() const {
return valueType == ValueType::ITERATOR_START;
}
bool isIteratorEndValue() const {
return valueType == ValueType::ITERATOR_END;
}
bool isSymbolicValue() const {
return valueType == ValueType::SYMBOLIC;
}
bool isLocalLifetimeValue() const {
return valueType == ValueType::LIFETIME && lifetimeScope == LifetimeScope::Local;
}
bool isArgumentLifetimeValue() const {
return valueType == ValueType::LIFETIME && lifetimeScope == LifetimeScope::Argument;
}
bool isSubFunctionLifetimeValue() const {
return valueType == ValueType::LIFETIME && lifetimeScope == LifetimeScope::SubFunction;
}
bool isNonValue() const {
return isMovedValue() || isUninitValue() || isLifetimeValue();
}
/** The value bound */
Bound bound;
/** int value (or sometimes bool value?) */
long long intvalue;
/** token value - the token that has the value. this is used for pointer aliases, strings, etc. */
const Token *tokvalue;
/** float value */
double floatValue;
/** kind of moved */
enum class MoveKind {NonMovedVariable, MovedVariable, ForwardedVariable} moveKind;
/** For calculated values - variable value that calculated value depends on */
long long varvalue;
/** Condition that this value depends on */
const Token *condition;
ErrorPath errorPath;
/** For calculated values - varId that calculated value depends on */
nonneg int varId;
/** value relies on safe checking */
bool safe;
/** Conditional value */
bool conditional;
/** Value is is from an expanded macro */
bool macro;
/** Is this value passed as default parameter to the function? */
bool defaultArg;
int indirect;
/** Path id */
MathLib::bigint path;
/** int value before implicit truncation */
long long wideintvalue;
std::vector<std::string> subexpressions;
enum class LifetimeKind {
// Pointer points to a member of lifetime
Object,
// A member of object points to the lifetime
SubObject,
// Lambda has captured lifetime(similar to SubObject)
Lambda,
// Iterator points to the lifetime of a container(similar to Object)
Iterator,
// A pointer that holds the address of the lifetime
Address
} lifetimeKind;
enum class LifetimeScope { Local, Argument, SubFunction } lifetimeScope;
static const char* toString(MoveKind moveKind);
static const char* toString(LifetimeKind lifetimeKind);
static const char* toString(LifetimeScope lifetimeScope);
static const char* toString(Bound bound);
/** How known is this value */
enum class ValueKind {
/** This value is possible, other unlisted values may also be possible */
Possible,
/** Only listed values are possible */
Known,
/** Inconclusive */
Inconclusive,
/** Listed values are impossible */
Impossible
} valueKind;
void setKnown() {
valueKind = ValueKind::Known;
}
bool isKnown() const {
return valueKind == ValueKind::Known;
}
void setPossible() {
valueKind = ValueKind::Possible;
}
bool isPossible() const {
return valueKind == ValueKind::Possible;
}
bool isImpossible() const {
return valueKind == ValueKind::Impossible;
}
void setImpossible() {
valueKind = ValueKind::Impossible;
}
void setInconclusive(bool inconclusive = true) {
if (inconclusive)
valueKind = ValueKind::Inconclusive;
}
bool isInconclusive() const {
return valueKind == ValueKind::Inconclusive;
}
void changeKnownToPossible() {
if (isKnown())
valueKind = ValueKind::Possible;
}
bool errorSeverity() const {
return !condition && !defaultArg;
}
static bool sameToken(const Token* tok1, const Token* tok2);
};
/// Constant folding of expression. This can be used before the full ValueFlow has been executed (ValueFlow::setValues).
const ValueFlow::Value * valueFlowConstantFoldAST(Token *expr, const Settings *settings);
/// Perform valueflow analysis.
void setValues(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings);
std::string eitherTheConditionIsRedundant(const Token *condition);
size_t getSizeOf(const ValueType &vt, const Settings *settings);
const ValueFlow::Value* findValue(const std::list<ValueFlow::Value>& values,
const Settings* settings,
std::function<bool(const ValueFlow::Value&)> pred);
std::vector<ValueFlow::Value> isOutOfBounds(const Value& size, const Token* indexTok, bool possible = true);
}
struct LifetimeToken {
const Token* token;
bool addressOf;
ValueFlow::Value::ErrorPath errorPath;
bool inconclusive;
LifetimeToken() : token(nullptr), addressOf(false), errorPath(), inconclusive(false) {}
LifetimeToken(const Token* token, ValueFlow::Value::ErrorPath errorPath)
: token(token), addressOf(false), errorPath(std::move(errorPath)), inconclusive(false)
{}
LifetimeToken(const Token* token, bool addressOf, ValueFlow::Value::ErrorPath errorPath)
: token(token), addressOf(addressOf), errorPath(std::move(errorPath)), inconclusive(false)
{}
static std::vector<LifetimeToken> setAddressOf(std::vector<LifetimeToken> v, bool b) {
for (LifetimeToken& x : v)
x.addressOf = b;
return v;
}
static std::vector<LifetimeToken> setInconclusive(std::vector<LifetimeToken> v, bool b) {
for (LifetimeToken& x : v)
x.inconclusive = b;
return v;
}
};
const Token *parseCompareInt(const Token *tok, ValueFlow::Value &true_value, ValueFlow::Value &false_value, const std::function<std::vector<MathLib::bigint>(const Token*)>& evaluate);
const Token *parseCompareInt(const Token *tok, ValueFlow::Value &true_value, ValueFlow::Value &false_value);
ValueFlow::Value inferCondition(std::string op, MathLib::bigint val, const Token* varTok);
ValueFlow::Value inferCondition(const std::string& op, const Token* varTok, MathLib::bigint val);
ValuePtr<InferModel> makeIntegralInferModel();
std::vector<LifetimeToken> getLifetimeTokens(const Token* tok,
bool escape = false,
ValueFlow::Value::ErrorPath errorPath = ValueFlow::Value::ErrorPath{});
bool hasLifetimeToken(const Token* tok, const Token* lifetime);
const Variable* getLifetimeVariable(const Token* tok, ValueFlow::Value::ErrorPath& errorPath, bool* addressOf = nullptr);
const Variable* getLifetimeVariable(const Token* tok);
bool isLifetimeBorrowed(const Token *tok, const Settings *settings);
std::string lifetimeType(const Token *tok, const ValueFlow::Value *val);
std::string lifetimeMessage(const Token *tok, const ValueFlow::Value *val, ValueFlow::Value::ErrorPath &errorPath);
CPPCHECKLIB ValueFlow::Value getLifetimeObjValue(const Token *tok, bool inconclusive = false);
CPPCHECKLIB std::vector<ValueFlow::Value> getLifetimeObjValues(const Token *tok, bool inconclusive = false, bool subfunction = false);
#endif // valueflowH