cppcheck/lib/checkstring.h

133 lines
5.4 KiB
C++

/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2019 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 checkstringH
#define checkstringH
//---------------------------------------------------------------------------
#include "check.h"
#include "config.h"
#include <string>
class ErrorLogger;
class Settings;
class Token;
class Tokenizer;
/// @addtogroup Checks
/// @{
/** @brief Detect misusage of C-style strings and related standard functions */
class CPPCHECKLIB CheckString : public Check {
public:
/** @brief This constructor is used when registering the CheckClass */
CheckString() : Check(myName()) {
}
/** @brief This constructor is used when running checks. */
CheckString(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger)
: Check(myName(), tokenizer, settings, errorLogger) {
}
/** @brief Run checks against the normal token list */
void runChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) OVERRIDE {
CheckString checkString(tokenizer, settings, errorLogger);
// Checks
checkString.strPlusChar();
checkString.checkSuspiciousStringCompare();
checkString.stringLiteralWrite();
checkString.overlappingStrcmp();
checkString.checkIncorrectStringCompare();
checkString.sprintfOverlappingData();
checkString.checkAlwaysTrueOrFalseStringCompare();
}
/** @brief undefined behaviour, writing string literal */
void stringLiteralWrite();
/** @brief str plus char (unusual pointer arithmetic) */
void strPlusChar();
/** @brief %Check for using bad usage of strncmp and substr */
void checkIncorrectStringCompare();
/** @brief %Check for comparison of a string literal with a char* variable */
void checkSuspiciousStringCompare();
/** @brief %Check for suspicious code that compares string literals for equality */
void checkAlwaysTrueOrFalseStringCompare();
/** @brief %Check for overlapping strcmp() */
void overlappingStrcmp();
/** @brief %Check for overlapping source and destination passed to sprintf() */
void sprintfOverlappingData();
private:
void stringLiteralWriteError(const Token *tok, const Token *strValue);
void sprintfOverlappingDataError(const Token *funcTok, const Token *tok, const std::string &varname);
void strPlusCharError(const Token *tok);
void incorrectStringCompareError(const Token *tok, const std::string& func, const std::string &string);
void incorrectStringBooleanError(const Token *tok, const std::string& string);
void alwaysTrueFalseStringCompareError(const Token *tok, const std::string& str1, const std::string& str2);
void alwaysTrueStringVariableCompareError(const Token *tok, const std::string& str1, const std::string& str2);
void suspiciousStringCompareError(const Token* tok, const std::string& var, bool isLong);
void suspiciousStringCompareError_char(const Token* tok, const std::string& var);
void overlappingStrcmpError(const Token* eq0, const Token *ne0);
void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings) const OVERRIDE {
CheckString c(nullptr, settings, errorLogger);
c.stringLiteralWriteError(nullptr, nullptr);
c.sprintfOverlappingDataError(nullptr, nullptr, "varname");
c.strPlusCharError(nullptr);
c.incorrectStringCompareError(nullptr, "substr", "\"Hello World\"");
c.suspiciousStringCompareError(nullptr, "foo", false);
c.suspiciousStringCompareError_char(nullptr, "foo");
c.incorrectStringBooleanError(nullptr, "\"Hello World\"");
c.incorrectStringBooleanError(nullptr, "\'x\'");
c.alwaysTrueFalseStringCompareError(nullptr, "str1", "str2");
c.alwaysTrueStringVariableCompareError(nullptr, "varname1", "varname2");
c.overlappingStrcmpError(nullptr, nullptr);
}
static std::string myName() {
return "String";
}
std::string classInfo() const OVERRIDE {
return "Detect misusage of C-style strings:\n"
"- overlapping buffers passed to sprintf as source and destination\n"
"- incorrect length arguments for 'substr' and 'strncmp'\n"
"- suspicious condition (runtime comparison of string literals)\n"
"- suspicious condition (string/char literals as boolean)\n"
"- suspicious comparison of a string literal with a char\\* variable\n"
"- suspicious comparison of '\\0' with a char\\* variable\n"
"- overlapping strcmp() expression\n";
}
};
/// @}
//---------------------------------------------------------------------------
#endif // checkstringH