200 lines
8.2 KiB
C++
200 lines
8.2 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2019 Cppcheck team.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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//---------------------------------------------------------------------------
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#ifndef checkconditionH
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#define checkconditionH
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//---------------------------------------------------------------------------
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#include "check.h"
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#include "config.h"
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#include "mathlib.h"
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#include <string>
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class ErrorLogger;
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class Settings;
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class Token;
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class Tokenizer;
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/// @addtogroup Checks
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/// @{
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/**
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* @brief Check for condition mismatches
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*/
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class CPPCHECKLIB CheckCondition : public Check {
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public:
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/** This constructor is used when registering the CheckAssignIf */
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CheckCondition() : Check(myName()) {
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}
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/** This constructor is used when running checks. */
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CheckCondition(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger)
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: Check(myName(), tokenizer, settings, errorLogger) {
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}
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void runChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) OVERRIDE {
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CheckCondition checkCondition(tokenizer, settings, errorLogger);
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checkCondition.multiCondition();
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checkCondition.clarifyCondition(); // not simplified because ifAssign
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checkCondition.multiCondition2();
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checkCondition.checkIncorrectLogicOperator();
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checkCondition.checkInvalidTestForOverflow();
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checkCondition.alwaysTrueFalse();
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checkCondition.duplicateCondition();
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checkCondition.checkPointerAdditionResultNotNull();
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checkCondition.assignIf();
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checkCondition.checkBadBitmaskCheck();
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checkCondition.comparison();
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checkCondition.checkModuloAlwaysTrueFalse();
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}
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/** mismatching assignment / comparison */
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void assignIf();
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/** parse scopes recursively */
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bool assignIfParseScope(const Token * const assignTok,
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const Token * const startTok,
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const unsigned int varid,
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const bool islocal,
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const char bitop,
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const MathLib::bigint num);
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/** check bitmask using | instead of & */
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void checkBadBitmaskCheck();
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/** mismatching lhs and rhs in comparison */
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void comparison();
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void duplicateCondition();
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/** match 'if' and 'else if' conditions */
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void multiCondition();
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/**
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* multiconditions #2
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* - Opposite inner conditions => always false
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* - (TODO) Same/Overlapping inner condition => always true
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* - same condition after early exit => always false
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**/
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void multiCondition2();
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/** @brief %Check for testing for mutual exclusion over ||*/
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void checkIncorrectLogicOperator();
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/** @brief %Check for suspicious usage of modulo (e.g. "if(var % 4 == 4)") */
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void checkModuloAlwaysTrueFalse();
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/** @brief Suspicious condition (assignment+comparison) */
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void clarifyCondition();
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/** @brief Condition is always true/false */
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void alwaysTrueFalse();
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/** @brief %Check for invalid test for overflow 'x+100 < x' */
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void checkInvalidTestForOverflow();
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/** @brief Check if pointer addition result is NULL '(ptr + 1) == NULL' */
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void checkPointerAdditionResultNotNull();
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private:
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// The conditions that have been diagnosed
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std::set<const Token*> mCondDiags;
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bool diag(const Token* tok, bool insert=true);
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bool isAliased(const std::set<unsigned int> &vars) const;
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bool isOverlappingCond(const Token * const cond1, const Token * const cond2, bool pure) const;
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void assignIfError(const Token *tok1, const Token *tok2, const std::string &condition, bool result);
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void mismatchingBitAndError(const Token *tok1, const MathLib::bigint num1, const Token *tok2, const MathLib::bigint num2);
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void badBitmaskCheckError(const Token *tok);
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void comparisonError(const Token *tok,
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const std::string &bitop,
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MathLib::bigint value1,
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const std::string &op,
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MathLib::bigint value2,
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bool result);
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void duplicateConditionError(const Token *tok1, const Token *tok2, ErrorPath errorPath);
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void multiConditionError(const Token *tok, unsigned int line1);
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void oppositeInnerConditionError(const Token *tok1, const Token* tok2, ErrorPath errorPath);
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void identicalInnerConditionError(const Token *tok1, const Token* tok2, ErrorPath errorPath);
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void identicalConditionAfterEarlyExitError(const Token *cond1, const Token *cond2, ErrorPath errorPath);
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void incorrectLogicOperatorError(const Token *tok, const std::string &condition, bool always, bool inconclusive, ErrorPath errors);
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void redundantConditionError(const Token *tok, const std::string &text, bool inconclusive);
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void moduloAlwaysTrueFalseError(const Token* tok, const std::string& maxVal);
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void clarifyConditionError(const Token *tok, bool assign, bool boolop);
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void alwaysTrueFalseError(const Token *tok, const ValueFlow::Value *value);
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void invalidTestForOverflow(const Token* tok, bool result);
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void pointerAdditionResultNotNullError(const Token *tok, const Token *calc);
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void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings) const OVERRIDE {
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CheckCondition c(nullptr, settings, errorLogger);
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ErrorPath errorPath;
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c.assignIfError(nullptr, nullptr, emptyString, false);
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c.badBitmaskCheckError(nullptr);
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c.comparisonError(nullptr, "&", 6, "==", 1, false);
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c.duplicateConditionError(nullptr, nullptr, errorPath);
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c.multiConditionError(nullptr,1);
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c.mismatchingBitAndError(nullptr, 0xf0, nullptr, 1);
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c.oppositeInnerConditionError(nullptr, nullptr, errorPath);
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c.identicalInnerConditionError(nullptr, nullptr, errorPath);
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c.identicalConditionAfterEarlyExitError(nullptr, nullptr, errorPath);
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c.incorrectLogicOperatorError(nullptr, "foo > 3 && foo < 4", true, false, errorPath);
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c.redundantConditionError(nullptr, "If x > 11 the condition x > 10 is always true.", false);
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c.moduloAlwaysTrueFalseError(nullptr, "1");
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c.clarifyConditionError(nullptr, true, false);
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c.alwaysTrueFalseError(nullptr, nullptr);
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c.invalidTestForOverflow(nullptr, false);
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c.pointerAdditionResultNotNullError(nullptr, nullptr);
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}
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static std::string myName() {
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return "Condition";
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}
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std::string classInfo() const OVERRIDE {
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return "Match conditions with assignments and other conditions:\n"
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"- Mismatching assignment and comparison => comparison is always true/false\n"
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"- Mismatching lhs and rhs in comparison => comparison is always true/false\n"
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"- Detect usage of | where & should be used\n"
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"- Detect matching 'if' and 'else if' conditions\n"
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"- Mismatching bitand (a &= 0xf0; a &= 1; => a = 0)\n"
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"- Opposite inner condition is always false\n"
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"- Identical condition after early exit is always false\n"
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"- Condition that is always true/false\n"
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"- Mutual exclusion over || always evaluating to true\n"
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"- Comparisons of modulo results that are always true/false.\n"
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"- Known variable values => condition is always true/false\n"
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"- Invalid test for overflow (for example 'ptr+u < ptr'). Condition is always false unless there is overflow, and overflow is undefined behaviour.\n";
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}
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};
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/// @}
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//---------------------------------------------------------------------------
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#endif // checkconditionH
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