cppcheck/lib/checkcondition.h

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/*
* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2022 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 checkconditionH
#define checkconditionH
//---------------------------------------------------------------------------
#include "check.h"
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#include "config.h"
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#include "mathlib.h"
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#include "errortypes.h"
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#include <set>
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#include <string>
class Settings;
class Token;
class Tokenizer;
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class ErrorLogger;
class ValueType;
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namespace ValueFlow {
class Value;
}
/// @addtogroup Checks
/// @{
/**
* @brief Check for condition mismatches
*/
class CPPCHECKLIB CheckCondition : public Check {
public:
/** This constructor is used when registering the CheckAssignIf */
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CheckCondition() : Check(myName()) {}
/** This constructor is used when running checks. */
CheckCondition(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger)
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: Check(myName(), tokenizer, settings, errorLogger) {}
void runChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) override {
CheckCondition checkCondition(tokenizer, settings, errorLogger);
checkCondition.multiCondition();
checkCondition.clarifyCondition(); // not simplified because ifAssign
checkCondition.multiCondition2();
checkCondition.checkIncorrectLogicOperator();
checkCondition.checkInvalidTestForOverflow();
checkCondition.duplicateCondition();
checkCondition.checkPointerAdditionResultNotNull();
checkCondition.checkDuplicateConditionalAssign();
checkCondition.assignIf();
checkCondition.alwaysTrueFalse();
checkCondition.checkBadBitmaskCheck();
checkCondition.comparison();
checkCondition.checkModuloAlwaysTrueFalse();
checkCondition.checkAssignmentInCondition();
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checkCondition.checkCompareValueOutOfTypeRange();
}
/** mismatching assignment / comparison */
void assignIf();
/** parse scopes recursively */
bool assignIfParseScope(const Token * const assignTok,
const Token * const startTok,
const nonneg int varid,
const bool islocal,
const char bitop,
const MathLib::bigint num);
/** check bitmask using | instead of & */
void checkBadBitmaskCheck();
/** mismatching lhs and rhs in comparison */
void comparison();
void duplicateCondition();
/** match 'if' and 'else if' conditions */
void multiCondition();
/**
* multiconditions #2
* - Opposite inner conditions => always false
* - (TODO) Same/Overlapping inner condition => always true
* - same condition after early exit => always false
**/
void multiCondition2();
/** @brief %Check for testing for mutual exclusion over ||*/
void checkIncorrectLogicOperator();
/** @brief %Check for suspicious usage of modulo (e.g. "if(var % 4 == 4)") */
void checkModuloAlwaysTrueFalse();
/** @brief Suspicious condition (assignment+comparison) */
void clarifyCondition();
/** @brief Condition is always true/false */
void alwaysTrueFalse();
/** @brief %Check for invalid test for overflow 'x+100 < x' */
void checkInvalidTestForOverflow();
/** @brief Check if pointer addition result is NULL '(ptr + 1) == NULL' */
void checkPointerAdditionResultNotNull();
void checkDuplicateConditionalAssign();
/** @brief Assignment in condition */
void checkAssignmentInCondition();
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private:
// The conditions that have been diagnosed
std::set<const Token*> mCondDiags;
bool diag(const Token* tok, bool insert=true);
bool isAliased(const std::set<int> &vars) const;
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bool isOverlappingCond(const Token * const cond1, const Token * const cond2, bool pure) const;
void assignIfError(const Token *tok1, const Token *tok2, const std::string &condition, bool result);
void mismatchingBitAndError(const Token *tok1, const MathLib::bigint num1, const Token *tok2, const MathLib::bigint num2);
void badBitmaskCheckError(const Token *tok);
void comparisonError(const Token *tok,
const std::string &bitop,
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MathLib::bigint value1,
const std::string &op,
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MathLib::bigint value2,
bool result);
void duplicateConditionError(const Token *tok1, const Token *tok2, ErrorPath errorPath);
void overlappingElseIfConditionError(const Token *tok, nonneg int line1);
void oppositeElseIfConditionError(const Token *ifCond, const Token *elseIfCond, ErrorPath errorPath);
void oppositeInnerConditionError(const Token *tok1, const Token* tok2, ErrorPath errorPath);
void identicalInnerConditionError(const Token *tok1, const Token* tok2, ErrorPath errorPath);
void identicalConditionAfterEarlyExitError(const Token *cond1, const Token *cond2, ErrorPath errorPath);
void incorrectLogicOperatorError(const Token *tok, const std::string &condition, bool always, bool inconclusive, ErrorPath errors);
void redundantConditionError(const Token *tok, const std::string &text, bool inconclusive);
void moduloAlwaysTrueFalseError(const Token* tok, const std::string& maxVal);
void clarifyConditionError(const Token *tok, bool assign, bool boolop);
void alwaysTrueFalseError(const Token *tok, const ValueFlow::Value *value);
void invalidTestForOverflow(const Token* tok, const ValueType *valueType, const std::string &replace);
void pointerAdditionResultNotNullError(const Token *tok, const Token *calc);
void duplicateConditionalAssignError(const Token *condTok, const Token* assignTok);
void assignmentInCondition(const Token *eq);
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void checkCompareValueOutOfTypeRange();
void compareValueOutOfTypeRangeError(const Token *comparison, const std::string &type, long long value, bool result);
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void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings) const override {
CheckCondition c(nullptr, settings, errorLogger);
ErrorPath errorPath;
c.assignIfError(nullptr, nullptr, emptyString, false);
c.badBitmaskCheckError(nullptr);
c.comparisonError(nullptr, "&", 6, "==", 1, false);
c.duplicateConditionError(nullptr, nullptr, errorPath);
c.overlappingElseIfConditionError(nullptr, 1);
c.mismatchingBitAndError(nullptr, 0xf0, nullptr, 1);
c.oppositeInnerConditionError(nullptr, nullptr, errorPath);
c.identicalInnerConditionError(nullptr, nullptr, errorPath);
c.identicalConditionAfterEarlyExitError(nullptr, nullptr, errorPath);
c.incorrectLogicOperatorError(nullptr, "foo > 3 && foo < 4", true, false, errorPath);
c.redundantConditionError(nullptr, "If x > 11 the condition x > 10 is always true.", false);
c.moduloAlwaysTrueFalseError(nullptr, "1");
c.clarifyConditionError(nullptr, true, false);
c.alwaysTrueFalseError(nullptr, nullptr);
c.invalidTestForOverflow(nullptr, nullptr, "false");
c.pointerAdditionResultNotNullError(nullptr, nullptr);
c.duplicateConditionalAssignError(nullptr, nullptr);
c.assignmentInCondition(nullptr);
c.compareValueOutOfTypeRangeError(nullptr, "unsigned char", 256, true);
}
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static std::string myName() {
return "Condition";
}
std::string classInfo() const override {
return "Match conditions with assignments and other conditions:\n"
"- Mismatching assignment and comparison => comparison is always true/false\n"
"- Mismatching lhs and rhs in comparison => comparison is always true/false\n"
"- Detect usage of | where & should be used\n"
"- Duplicate condition and assignment\n"
"- Detect matching 'if' and 'else if' conditions\n"
"- Mismatching bitand (a &= 0xf0; a &= 1; => a = 0)\n"
"- Opposite inner condition is always false\n"
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"- Identical condition after early exit is always false\n"
"- Condition that is always true/false\n"
"- Mutual exclusion over || always evaluating to true\n"
"- Comparisons of modulo results that are always true/false.\n"
"- Known variable values => condition is always true/false\n"
"- Invalid test for overflow. Some mainstream compilers remove such overflow tests when optimising code.\n"
"- Suspicious assignment of container/iterator in condition => condition is always true.\n";
}
};
/// @}
//---------------------------------------------------------------------------
#endif // checkconditionH