/* * Cppcheck - A tool for static C/C++ code analysis * Copyright (C) 2007-2011 Daniel Marjamäki and 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 . */ //--------------------------------------------------------------------------- #include "checkother.h" #include "mathlib.h" #include "symboldatabase.h" #include // std::isupper #include // fabs() #include //--------------------------------------------------------------------------- // Register this check class (by creating a static instance of it) namespace { CheckOther instance; } //--------------------------------------------------------------------------- void CheckOther::checkIncrementBoolean() { if (!_settings->_checkCodingStyle) return; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "%var% ++")) { if (tok->varId()) { const Token *declTok = Token::findmatch(_tokenizer->tokens(), "bool %varid%", tok->varId()); if (declTok) incrementBooleanError(tok); } } } } void CheckOther::incrementBooleanError(const Token *tok) { reportError( tok, Severity::style, "incrementboolean", "The use of a variable of type bool with the ++ postfix operator is always true and deprecated by the C++ Standard.\n" "The operand of a postfix increment operator may be of type bool but it is deprecated by C++ Standard (Annex D-1) and the operand is always set to true\n" ); } //--------------------------------------------------------------------------- void CheckOther::clarifyCalculation() { if (!_settings->_checkCodingStyle) return; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->strAt(1) == "?") { // condition const Token *cond = tok; if (cond->isName() || cond->isNumber()) cond = cond->previous(); else if (cond->str() == ")") cond = cond->link()->previous(); else continue; // calculation if (!cond->isArithmeticalOp()) continue; const std::string &op = cond->str(); cond = cond->previous(); // skip previous multiplications.. while (cond && cond->strAt(-1) == "*" && (cond->isName() || cond->isNumber())) cond = cond->tokAt(-2); if (!cond) continue; // first multiplication operand if (cond->str() == ")") { clarifyCalculationError(cond, op); } else if (cond->isName() || cond->isNumber()) { if (Token::Match(cond->previous(),("return|=|+|-|,|(|"+op).c_str())) clarifyCalculationError(cond, op); } } } } void CheckOther::clarifyCalculationError(const Token *tok, const std::string &op) { // suspicious calculation const std::string calc("'a" + op + "b?c:d'"); // recommended calculation #1 const std::string s1("'(a" + op + "b)?c:d'"); // recommended calculation #2 const std::string s2("'a" + op + "(b?c:d)'"); reportError(tok, Severity::style, "clarifyCalculation", "Clarify calculation precedence for " + op + " and ?\n" "Suspicious calculation. Please use parentheses to clarify the code. " "The code " + calc + " should be written as either " + s1 + " or " + s2 + "."); } // Clarify condition '(x = a < 0)' into '((x = a) < 0)' or '(x = (a < 0))' void CheckOther::clarifyCondition() { if (!_settings->_checkCodingStyle) return; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "( %var% =")) { for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) { if (tok2->str() == "(" || tok2->str() == "[") tok2 = tok2->link(); else if (Token::Match(tok2, "&&|%oror%|?|)")) break; else if (Token::Match(tok2, "<|<=|==|!=|>|>= %num% )")) { clarifyConditionError(tok); break; } } } } } void CheckOther::clarifyConditionError(const Token *tok) { reportError(tok, Severity::style, "clarifyCondition", "Suspicious condition (assignment+comparison), it can be clarified with parentheses"); } void CheckOther::warningOldStylePointerCast() { if (!_settings->_checkCodingStyle || (_tokenizer->tokens() && _tokenizer->fileLine(_tokenizer->tokens()).find(".cpp") == std::string::npos)) return; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { // Old style pointer casting.. if (!Token::Match(tok, "( const| %type% * ) %var%") && !Token::Match(tok, "( const| %type% * ) (| new")) continue; int addToIndex = 0; if (tok->tokAt(1)->str() == "const") addToIndex = 1; if (tok->tokAt(4 + addToIndex)->str() == "const") continue; // Is "type" a class? const std::string pattern("class " + tok->tokAt(1 + addToIndex)->str()); if (!Token::findmatch(_tokenizer->tokens(), pattern.c_str())) continue; cstyleCastError(tok); } } //--------------------------------------------------------------------------- // fflush(stdin) <- fflush only applies to output streams in ANSI C //--------------------------------------------------------------------------- void CheckOther::checkFflushOnInputStream() { const Token *tok = _tokenizer->tokens(); while (tok && ((tok = Token::findmatch(tok, "fflush ( stdin )")) != NULL)) { fflushOnInputStreamError(tok, tok->strAt(2)); tok = tok->tokAt(4); } } void CheckOther::checkSizeofForArrayParameter() { for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "sizeof ( %var% )") || Token::Match(tok, "sizeof %var%")) { int tokIdx = 1; if (tok->tokAt(tokIdx)->str() == "(") { ++tokIdx; } if (tok->tokAt(tokIdx)->varId() > 0) { const Token *declTok = Token::findmatch(_tokenizer->tokens(), "%varid%", tok->tokAt(tokIdx)->varId()); if (declTok) { if (Token::simpleMatch(declTok->next(), "[")) { declTok = declTok->next()->link(); // multidimensional array while (Token::simpleMatch(declTok->next(), "[")) { declTok = declTok->next()->link(); } if (!(Token::Match(declTok->next(), "= %str%")) && !(Token::simpleMatch(declTok->next(), "= {")) && !(Token::simpleMatch(declTok->next(), ";"))) { if (Token::simpleMatch(declTok->next(), ",")) { declTok = declTok->next(); while (!Token::simpleMatch(declTok, ";")) { if (Token::simpleMatch(declTok, ")")) { sizeofForArrayParameterError(tok); break; } if (Token::Match(declTok, "(|[|{")) { declTok = declTok->link(); } declTok = declTok->next(); } } } if (Token::simpleMatch(declTok->next(), ")")) { sizeofForArrayParameterError(tok); } } } } } } } //--------------------------------------------------------------------------- // switch (x) // { // case 2: // y = a; // <- this assignment is redundant // case 3: // y = b; // <- case 2 falls through and sets y twice // } //--------------------------------------------------------------------------- void CheckOther::checkRedundantAssignmentInSwitch() { const char switchPattern[] = "switch ( %any% ) { case"; const char breakPattern[] = "break|continue|return|exit|goto|throw"; const char functionPattern[] = "%var% ("; // Find the beginning of a switch. E.g.: // switch (var) { ... const Token *tok = Token::findmatch(_tokenizer->tokens(), switchPattern); while (tok) { // Check the contents of the switch statement std::map varsAssigned; int indentLevel = 0; for (const Token *tok2 = tok->tokAt(5); tok2; tok2 = tok2->next()) { if (tok2->str() == "{") { // Inside a conditional or loop. Don't mark variable accesses as being redundant. E.g.: // case 3: b = 1; // case 4: if (a) { b = 2; } // Doesn't make the b=1 redundant because it's conditional if (Token::Match(tok2->previous(), ")|else {") && tok2->link()) { const Token* endOfConditional = tok2->link(); for (const Token* tok3 = tok2; tok3 != endOfConditional; tok3 = tok3->next()) { if (tok3->varId() != 0) varsAssigned.erase(tok3->varId()); else if (Token::Match(tok3, functionPattern) || Token::Match(tok3, breakPattern)) varsAssigned.clear(); } tok2 = endOfConditional; } else ++ indentLevel; } else if (tok2->str() == "}") { -- indentLevel; // End of the switch block if (indentLevel < 0) break; } // Variable assignment. Report an error if it's assigned to twice before a break. E.g.: // case 3: b = 1; // <== redundant // case 4: b = 2; if (Token::Match(tok2->previous(), ";|{|}|: %var% = %any% ;") && tok2->varId() != 0) { std::map::iterator i = varsAssigned.find(tok2->varId()); if (i == varsAssigned.end()) varsAssigned[tok2->varId()] = tok2; else redundantAssignmentInSwitchError(i->second, i->second->str()); } // Not a simple assignment so there may be good reason if this variable is assigned to twice. E.g.: // case 3: b = 1; // case 4: b++; else if (tok2->varId() != 0) varsAssigned.erase(tok2->varId()); // Reset our record of assignments if there is a break or function call. E.g.: // case 3: b = 1; break; if (Token::Match(tok2, functionPattern) || Token::Match(tok2, breakPattern)) varsAssigned.clear(); } tok = Token::findmatch(tok->next(), switchPattern); } } void CheckOther::checkSwitchCaseFallThrough() { if (!(_settings->_checkCodingStyle && _settings->stupid)) return; const char switchPattern[] = "switch ("; const char breakPattern[] = "break|continue|return|exit|goto|throw"; // Find the beginning of a switch. E.g.: // switch (var) { ... const Token *tok = Token::findmatch(_tokenizer->tokens(), switchPattern); while (tok) { // Check the contents of the switch statement std::stack > ifnest; std::stack loopnest; std::stack scopenest; bool justbreak = true; bool firstcase = true; for (const Token *tok2 = tok->tokAt(1)->link()->tokAt(2); tok2; tok2 = tok2->next()) { if (Token::Match(tok2, "if (")) { tok2 = tok2->tokAt(1)->link()->next(); if (tok2->link() == NULL) { std::ostringstream errmsg; errmsg << "unmatched if in switch: " << tok2->linenr(); reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str()); break; } ifnest.push(std::make_pair(tok2->link(), false)); justbreak = false; } else if (Token::Match(tok2, "while (")) { tok2 = tok2->tokAt(1)->link()->next(); // skip over "do { } while ( ) ;" case if (tok2->str() == "{") { if (tok2->link() == NULL) { std::ostringstream errmsg; errmsg << "unmatched while in switch: " << tok2->linenr(); reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str()); break; } loopnest.push(tok2->link()); } justbreak = false; } else if (Token::Match(tok2, "do {")) { tok2 = tok2->tokAt(1); if (tok2->link() == NULL) { std::ostringstream errmsg; errmsg << "unmatched do in switch: " << tok2->linenr(); reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str()); break; } loopnest.push(tok2->link()); justbreak = false; } else if (Token::Match(tok2, "for (")) { tok2 = tok2->tokAt(1)->link()->next(); if (tok2->link() == NULL) { std::ostringstream errmsg; errmsg << "unmatched for in switch: " << tok2->linenr(); reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str()); break; } loopnest.push(tok2->link()); justbreak = false; } else if (Token::Match(tok2, switchPattern)) { // skip over nested switch, we'll come to that soon tok2 = tok2->tokAt(1)->link()->next()->link(); } else if (Token::Match(tok2, breakPattern)) { if (loopnest.empty()) { justbreak = true; } tok2 = Token::findmatch(tok2, ";"); } else if (Token::Match(tok2, "case|default")) { if (!justbreak && !firstcase) { switchCaseFallThrough(tok2); } tok2 = Token::findmatch(tok2, ":"); justbreak = true; firstcase = false; } else if (tok2->str() == "{") { scopenest.push(tok2->link()); } else if (tok2->str() == "}") { if (!ifnest.empty() && tok2 == ifnest.top().first) { if (tok2->next()->str() == "else") { tok2 = tok2->tokAt(2); ifnest.pop(); if (tok2->link() == NULL) { std::ostringstream errmsg; errmsg << "unmatched if in switch: " << tok2->linenr(); reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str()); break; } ifnest.push(std::make_pair(tok2->link(), justbreak)); justbreak = false; } else { justbreak &= ifnest.top().second; ifnest.pop(); } } else if (!loopnest.empty() && tok2 == loopnest.top()) { loopnest.pop(); } else if (!scopenest.empty() && tok2 == scopenest.top()) { scopenest.pop(); } else { if (!ifnest.empty() || !loopnest.empty() || !scopenest.empty()) { std::ostringstream errmsg; errmsg << "unexpected end of switch: "; errmsg << "ifnest=" << ifnest.size(); if (!ifnest.empty()) errmsg << "," << ifnest.top().first->linenr(); errmsg << ", loopnest=" << loopnest.size(); if (!loopnest.empty()) errmsg << "," << loopnest.top()->linenr(); errmsg << ", scopenest=" << scopenest.size(); if (!scopenest.empty()) errmsg << "," << scopenest.top()->linenr(); reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str()); } // end of switch block break; } } else if (tok2->str() != ";") { justbreak = false; } } tok = Token::findmatch(tok->next(), switchPattern); } } //--------------------------------------------------------------------------- // int x = 1; // x = x; // <- redundant assignment to self // // int y = y; // <- redundant initialization to self //--------------------------------------------------------------------------- void CheckOther::checkSelfAssignment() { if (!_settings->_checkCodingStyle) return; // POD variables.. std::set pod; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->isStandardType() && Token::Match(tok->tokAt(2), "[,);]") && tok->next()->varId()) pod.insert(tok->next()->varId()); } const char selfAssignmentPattern[] = "%var% = %var% ;|=|)"; const Token *tok = Token::findmatch(_tokenizer->tokens(), selfAssignmentPattern); while (tok) { if (Token::Match(tok->previous(), "[;{}]") && tok->varId() && tok->varId() == tok->tokAt(2)->varId() && pod.find(tok->varId()) != pod.end()) { selfAssignmentError(tok, tok->str()); } tok = Token::findmatch(tok->next(), selfAssignmentPattern); } } //--------------------------------------------------------------------------- // int a = 1; // assert(a = 2); // <- assert should not have a side-effect //--------------------------------------------------------------------------- void CheckOther::checkAssignmentInAssert() { if (!_settings->_checkCodingStyle) return; const char assertPattern[] = "assert ( %any%"; const Token *tok = Token::findmatch(_tokenizer->tokens(), assertPattern); const Token *endTok = tok ? tok->next()->link() : NULL; while (tok && endTok) { const Token* varTok = Token::findmatch(tok->tokAt(2), "%var% --|++|+=|-=|*=|/=|&=|^=|=", endTok); if (varTok) { assignmentInAssertError(tok, varTok->str()); } else if (NULL != (varTok = Token::findmatch(tok->tokAt(2), "--|++ %var%", endTok))) { assignmentInAssertError(tok, varTok->strAt(1)); } tok = Token::findmatch(endTok->next(), assertPattern); endTok = tok ? tok->next()->link() : NULL; } } //--------------------------------------------------------------------------- // if ((x != 1) || (x != 3)) // <- always true //--------------------------------------------------------------------------- void CheckOther::checkIncorrectLogicOperator() { if (!_settings->_checkCodingStyle) return; const char conditionPattern[] = "if|while ("; const Token *tok = Token::findmatch(_tokenizer->tokens(), conditionPattern); const Token *endTok = tok ? tok->next()->link() : NULL; while (tok && endTok) { // Find a pair of OR'd terms, with or without parenthesis // e.g. if (x != 3 || x != 4) const Token *logicTok = NULL, *term1Tok = NULL, *term2Tok = NULL; if (NULL != (logicTok = Token::findmatch(tok, "( %any% != %any% ) %oror% ( %any% != %any% ) !!&&", endTok))) { term1Tok = logicTok->next(); term2Tok = logicTok->tokAt(7); } else if (NULL != (logicTok = Token::findmatch(tok, "%any% != %any% %oror% %any% != %any% !!&&", endTok))) { term1Tok = logicTok; term2Tok = logicTok->tokAt(4); } // The terms must not be AND'd with anything, to prevent false positives if (logicTok && (logicTok->strAt(-1) != "&&")) { // Find the common variable and the two different-valued constants unsigned int variableTested = 0; std::string firstConstant, secondConstant; if (Token::Match(term1Tok, "%var% != %num%")) { const unsigned int varId = term1Tok->varId(); if (!varId) { tok = Token::findmatch(endTok->next(), conditionPattern); endTok = tok ? tok->next()->link() : NULL; continue; } firstConstant = term1Tok->tokAt(2)->str(); if (Token::Match(term2Tok, "%varid% != %num%", varId)) { variableTested = varId; secondConstant = term2Tok->tokAt(2)->str(); } else if (Token::Match(term2Tok, "%num% != %varid%", varId)) { variableTested = varId; secondConstant = term2Tok->str(); } } else if (Token::Match(term1Tok, "%num% != %var%")) { const unsigned int varId = term1Tok->tokAt(2)->varId(); firstConstant = term1Tok->str(); if (Token::Match(term2Tok, "%varid% != %num%", varId)) { variableTested = varId; secondConstant = term2Tok->tokAt(2)->str(); } else if (Token::Match(term2Tok, "%num% != %varid%", varId)) { variableTested = varId; secondConstant = term2Tok->str(); } } // If there is a common variable tested for inequality against // either of two different-valued constants, then the expression // will always evaluate to true and the || probably should be an && if (variableTested != 0 && !firstConstant.empty() && !secondConstant.empty() && firstConstant != secondConstant) { incorrectLogicOperatorError(term1Tok); } } tok = Token::findmatch(endTok->next(), conditionPattern); endTok = tok ? tok->next()->link() : NULL; } } //--------------------------------------------------------------------------- // try {} catch (std::exception err) {} <- Should be "std::exception& err" //--------------------------------------------------------------------------- void CheckOther::checkCatchExceptionByValue() { if (!_settings->_checkCodingStyle) return; const char catchPattern[] = "} catch ("; const Token *tok = Token::findmatch(_tokenizer->tokens(), catchPattern); const Token *endTok = tok ? tok->tokAt(2)->link() : NULL; while (tok && endTok) { // Find a pass-by-value declaration in the catch(), excluding basic types // e.g. catch (std::exception err) const Token *tokType = Token::findmatch(tok, "%type% %var% )", endTok); if (tokType && !tokType->isStandardType()) { catchExceptionByValueError(tokType); } tok = Token::findmatch(endTok->next(), catchPattern); endTok = tok ? tok->tokAt(2)->link() : NULL; } } //--------------------------------------------------------------------------- // strtol(str, 0, radix) <- radix must be 0 or 2-36 //--------------------------------------------------------------------------- void CheckOther::invalidFunctionUsage() { // strtol and strtoul.. for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (!Token::Match(tok, "strtol|strtoul (")) continue; // Locate the third parameter of the function call.. int param = 1; for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) { if (tok2->str() == "(") tok2 = tok2->link(); else if (tok2->str() == ")") break; else if (tok2->str() == ",") { ++param; if (param == 3) { if (Token::Match(tok2, ", %num% )")) { const MathLib::bigint radix = MathLib::toLongNumber(tok2->next()->str()); if (!(radix == 0 || (radix >= 2 && radix <= 36))) { dangerousUsageStrtolError(tok2); } } break; } } } } // sprintf|snprintf overlapping data for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { // Get variable id of target buffer.. unsigned int varid = 0; if (Token::Match(tok, "sprintf|snprintf ( %var% ,")) varid = tok->tokAt(2)->varId(); else if (Token::Match(tok, "sprintf|snprintf ( %var% . %var% ,")) varid = tok->tokAt(4)->varId(); if (varid == 0) continue; // goto "," const Token *tok2 = tok->tokAt(3); while (tok2 && tok2->str() != ",") tok2 = tok2->next(); // is any source buffer overlapping the target buffer? int parlevel = 0; while ((tok2 = tok2->next()) != NULL) { if (tok2->str() == "(") ++parlevel; else if (tok2->str() == ")") { --parlevel; if (parlevel < 0) break; } else if (parlevel == 0 && Token::Match(tok2, ", %varid% [,)]", varid)) { sprintfOverlappingDataError(tok2->next(), tok2->next()->str()); break; } } } } //--------------------------------------------------------------------------- void CheckOther::invalidScanf() { if (!_settings->_checkCodingStyle) return; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { const Token *formatToken = 0; if (Token::Match(tok, "scanf|vscanf ( %str% ,")) formatToken = tok->tokAt(2); else if (Token::Match(tok, "fscanf|vfscanf ( %var% , %str% ,")) formatToken = tok->tokAt(4); else continue; bool format = false; // scan the string backwards, so we dont need to keep states const std::string &formatstr(formatToken->str()); for (unsigned int i = 1; i < formatstr.length(); i++) { if (formatstr[i] == '%') format = !format; else if (!format) continue; else if (std::isdigit(formatstr[i])) { format = false; } else if (std::isalpha(formatstr[i])) { invalidScanfError(tok); format = false; } } } } //--------------------------------------------------------------------------- // if (!x==3) <- Probably meant to be "x!=3" //--------------------------------------------------------------------------- void CheckOther::checkComparisonOfBoolWithInt() { if (!_settings->_checkCodingStyle) return; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "( ! %var% ==|!= %num% )")) { const Token *numTok = tok->tokAt(4); if (numTok && numTok->str() != "0") { comparisonOfBoolWithIntError(numTok, tok->strAt(2)); } } else if (Token::Match(tok, "( %num% ==|!= ! %var% )")) { const Token *numTok = tok->tokAt(1); if (numTok && numTok->str() != "0") { comparisonOfBoolWithIntError(numTok, tok->strAt(4)); } } } } void CheckOther::sizeofForArrayParameterError(const Token *tok) { reportError(tok, Severity::error, "sizeofwithsilentarraypointer", "Using sizeof for array given as function argument " "returns the size of pointer.\n" "Giving array as function parameter and then using sizeof-operator for the array " "argument. In this case the sizeof-operator returns the size of pointer (in the " "system). It does not return the size of the whole array in bytes as might be " "expected. For example, this code:\n" " int f(char a[100]) {\n" " return sizeof(a);\n" " }\n" " returns 4 (in 32-bit systems) or 8 (in 64-bit systems) instead of 100 (the " "size of the array in bytes)." ); } void CheckOther::invalidScanfError(const Token *tok) { reportError(tok, Severity::warning, "invalidscanf", "scanf without field width limits can crash with huge input data\n" "scanf without field width limits can crash with huge input data. To fix this error " "message add a field width specifier:\n" " %s => %20s\n" " %i => %3i\n" "\n" "Sample program that can crash:\n" "\n" "#include \n" "int main()\n" "{\n" " int a;\n" " scanf(\"%i\", &a);\n" " return 0;\n" "}\n" "\n" "To make it crash:\n" "perl -e 'print \"5\"x2100000' | ./a.out"); } //--------------------------------------------------------------------------- // Check for unsigned divisions //--------------------------------------------------------------------------- void CheckOther::checkUnsignedDivision() { if (!_settings->_checkCodingStyle) return; // Check for "ivar / uvar" and "uvar / ivar" std::map varsign; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "[{};(,] %type% %var% [;=,)]")) { if (tok->tokAt(1)->isUnsigned()) varsign[tok->tokAt(2)->varId()] = 'u'; else varsign[tok->tokAt(2)->varId()] = 's'; } else if (!Token::Match(tok, "[).]") && Token::Match(tok->next(), "%var% / %num%")) { if (tok->strAt(3)[0] == '-') { char sign1 = varsign[tok->tokAt(1)->varId()]; if (sign1 == 'u') { udivError(tok->next()); } } } else if (Token::Match(tok, "(|[|=|%op% %num% / %var%")) { if (tok->strAt(1)[0] == '-') { char sign2 = varsign[tok->tokAt(3)->varId()]; if (sign2 == 'u') { udivError(tok->next()); } } } } } //--------------------------------------------------------------------------- // memset(p, y, 0 /* bytes to fill */) <- 2nd and 3rd arguments inverted //--------------------------------------------------------------------------- void CheckOther::checkMemsetZeroBytes() { const Token *tok = _tokenizer->tokens(); while (tok && ((tok = Token::findmatch(tok, "memset ( %var% , %num% , 0 )")) != NULL)) { memsetZeroBytesError(tok, tok->strAt(2)); tok = tok->tokAt(8); } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Usage of function variables //--------------------------------------------------------------------------- /** * @brief This class is used to capture the control flow within a function. */ class ScopeInfo { public: ScopeInfo() : _token(NULL), _parent(NULL) { } ScopeInfo(const Token *token, ScopeInfo *parent_) : _token(token), _parent(parent_) { } ~ScopeInfo(); ScopeInfo *parent() { return _parent; } ScopeInfo *addChild(const Token *token); void remove(ScopeInfo *scope); private: const Token *_token; ScopeInfo *_parent; std::list _children; }; ScopeInfo::~ScopeInfo() { while (!_children.empty()) { delete *_children.begin(); _children.pop_front(); } } ScopeInfo *ScopeInfo::addChild(const Token *token) { ScopeInfo *temp = new ScopeInfo(token, this); _children.push_back(temp); return temp; } void ScopeInfo::remove(ScopeInfo *scope) { std::list::iterator it; for (it = _children.begin(); it != _children.end(); ++it) { if (*it == scope) { delete *it; _children.erase(it); break; } } } /** * @brief This class is used create a list of variables within a function. */ class Variables { public: enum VariableType { standard, array, pointer, reference, pointerArray, referenceArray, pointerPointer }; /** Store information about variable usage */ class VariableUsage { public: VariableUsage(const Token *name = 0, VariableType type = standard, ScopeInfo *scope = NULL, bool read = false, bool write = false, bool modified = false, bool allocateMemory = false) : _name(name), _type(type), _scope(scope), _read(read), _write(write), _modified(modified), _allocateMemory(allocateMemory) { } /** variable is used.. set both read+write */ void use() { _read = true; _write = true; } /** is variable unused? */ bool unused() const { return (_read == false && _write == false); } const Token *_name; VariableType _type; ScopeInfo *_scope; bool _read; bool _write; bool _modified; // read/modify/write bool _allocateMemory; std::set _aliases; std::set _assignments; }; typedef std::map VariableMap; void clear() { _varUsage.clear(); } VariableMap &varUsage() { return _varUsage; } void addVar(const Token *name, VariableType type, ScopeInfo *scope, bool write_); void allocateMemory(unsigned int varid); void read(unsigned int varid); void readAliases(unsigned int varid); void readAll(unsigned int varid); void write(unsigned int varid); void writeAliases(unsigned int varid); void writeAll(unsigned int varid); void use(unsigned int varid); void modified(unsigned int varid); VariableUsage *find(unsigned int varid); void alias(unsigned int varid1, unsigned int varid2, bool replace); void erase(unsigned int varid) { _varUsage.erase(varid); } void eraseAliases(unsigned int varid); void eraseAll(unsigned int varid); void clearAliases(unsigned int varid); private: VariableMap _varUsage; }; /** * Alias the 2 given variables. Either replace the existing aliases if * they exist or merge them. You would replace an existing alias when this * assignment is in the same scope as the previous assignment. You might * merge the aliases when this assignment is in a different scope from the * previous assignment depending on the relationship of the 2 scopes. */ void Variables::alias(unsigned int varid1, unsigned int varid2, bool replace) { VariableUsage *var1 = find(varid1); VariableUsage *var2 = find(varid2); // alias to self if (varid1 == varid2) { if (var1) var1->use(); return; } std::set::iterator i; if (replace) { // remove var1 from all aliases for (i = var1->_aliases.begin(); i != var1->_aliases.end(); ++i) { VariableUsage *temp = find(*i); if (temp) temp->_aliases.erase(var1->_name->varId()); } // remove all aliases from var1 var1->_aliases.clear(); } // var1 gets all var2s aliases for (i = var2->_aliases.begin(); i != var2->_aliases.end(); ++i) { if (*i != varid1) var1->_aliases.insert(*i); } // var2 is an alias of var1 var2->_aliases.insert(varid1); var1->_aliases.insert(varid2); if (var2->_type == Variables::pointer) var2->_read = true; } void Variables::clearAliases(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) { // remove usage from all aliases std::set::iterator i; for (i = usage->_aliases.begin(); i != usage->_aliases.end(); ++i) { VariableUsage *temp = find(*i); if (temp) temp->_aliases.erase(usage->_name->varId()); } // remove all aliases from usage usage->_aliases.clear(); } } void Variables::eraseAliases(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) { std::set::iterator aliases; for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases) erase(*aliases); } } void Variables::eraseAll(unsigned int varid) { eraseAliases(varid); erase(varid); } void Variables::addVar(const Token *name, VariableType type, ScopeInfo *scope, bool write_) { if (name->varId() > 0) _varUsage.insert(std::make_pair(name->varId(), VariableUsage(name, type, scope, false, write_, false))); } void Variables::allocateMemory(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) usage->_allocateMemory = true; } void Variables::read(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) usage->_read = true; } void Variables::readAliases(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) { std::set::iterator aliases; for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases) { VariableUsage *aliased = find(*aliases); if (aliased) aliased->_read = true; } } } void Variables::readAll(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) { usage->_read = true; std::set::iterator aliases; for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases) { VariableUsage *aliased = find(*aliases); if (aliased) aliased->_read = true; } } } void Variables::write(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) usage->_write = true; } void Variables::writeAliases(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) { std::set::iterator aliases; for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases) { VariableUsage *aliased = find(*aliases); if (aliased) aliased->_write = true; } } } void Variables::writeAll(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) { usage->_write = true; std::set::iterator aliases; for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases) { VariableUsage *aliased = find(*aliases); if (aliased) aliased->_write = true; } } } void Variables::use(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) { usage->use(); std::set::iterator aliases; for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases) { VariableUsage *aliased = find(*aliases); if (aliased) aliased->use(); } } } void Variables::modified(unsigned int varid) { VariableUsage *usage = find(varid); if (usage) { usage->_modified = true; std::set::iterator aliases; for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases) { VariableUsage *aliased = find(*aliases); if (aliased) aliased->_modified = true; } } } Variables::VariableUsage *Variables::find(unsigned int varid) { if (varid) { VariableMap::iterator i = _varUsage.find(varid); if (i != _varUsage.end()) return &i->second; } return 0; } static int doAssignment(Variables &variables, const Token *tok, bool dereference, ScopeInfo *scope) { int next = 0; // a = a + b; if (Token::Match(tok, "%var% = %var% !!;") && tok->str() == tok->strAt(2)) { return 2; } // check for aliased variable const unsigned int varid1 = tok->varId(); Variables::VariableUsage *var1 = variables.find(varid1); if (var1) { Variables::VariableUsage *var2 = 0; int start = 1; // search for '=' while (tok->tokAt(start)->str() != "=") start++; start++; if (Token::Match(tok->tokAt(start), "&| %var%") || Token::Match(tok->tokAt(start), "( const| struct|union| %type% *| ) &| %var%") || Token::Match(tok->tokAt(start), "( const| struct|union| %type% *| ) ( &| %var%") || Token::Match(tok->tokAt(start), "%any% < const| struct|union| %type% *| > ( &| %var%")) { unsigned char offset = 0; unsigned int varid2; bool addressOf = false; if (Token::Match(tok->tokAt(start), "%var% .")) variables.use(tok->tokAt(start)->varId()); // use = read + write // check for C style cast if (tok->tokAt(start)->str() == "(") { if (tok->tokAt(start + 1)->str() == "const") offset++; if (Token::Match(tok->tokAt(start + 1 + offset), "struct|union")) offset++; if (tok->tokAt(start + 2 + offset)->str() == "*") offset++; if (tok->tokAt(start + 3 + offset)->str() == "&") { addressOf = true; next = start + 4 + offset; } else if (tok->tokAt(start + 3 + offset)->str() == "(") { if (tok->tokAt(start + 4 + offset)->str() == "&") { addressOf = true; next = start + 5 + offset; } else next = start + 4 + offset; } else next = start + 3 + offset; } // check for C++ style cast else if (tok->tokAt(start)->str().find("cast") != std::string::npos && tok->tokAt(start + 1)->str() == "<") { if (tok->tokAt(start + 2)->str() == "const") offset++; if (Token::Match(tok->tokAt(start + 2 + offset), "struct|union")) offset++; if (tok->tokAt(start + 3 + offset)->str() == "*") offset++; if (tok->tokAt(start + 5 + offset)->str() == "&") { addressOf = true; next = start + 6 + offset; } else next = start + 5 + offset; } // check for var ? ... else if (Token::Match(tok->tokAt(start), "%var% ?")) { next = start; } // no cast else { if (tok->tokAt(start)->str() == "&") { addressOf = true; next = start + 1; } else if (tok->tokAt(start)->str() == "new") return 0; else next = start; } // check if variable is local varid2 = tok->tokAt(next)->varId(); var2 = variables.find(varid2); if (var2) // local variable (alias or read it) { if (var1->_type == Variables::pointer) { if (dereference) variables.read(varid2); else { if (addressOf || var2->_type == Variables::array || var2->_type == Variables::pointer) { bool replace = true; // check if variable declared in same scope if (scope == var1->_scope) replace = true; // not in same scope as declaration else { std::set::iterator assignment; // check for an assignment in this scope assignment = var1->_assignments.find(scope); // no other assignment in this scope if (assignment == var1->_assignments.end()) { // nothing to replace if (var1->_assignments.empty()) replace = false; // this variable has previous assignments else { /** * @todo determine if existing aliases should be replaced or merged */ replace = false; } } // assignment in this scope else { // replace when only one other assignment if (var1->_assignments.size() == 1) replace = true; // otherwise, merge them else replace = false; } } variables.alias(varid1, varid2, replace); } else if (tok->tokAt(next + 1)->str() == "?") { if (var2->_type == Variables::reference) variables.readAliases(varid2); else variables.read(varid2); } } } else if (var1->_type == Variables::reference) { variables.alias(varid1, varid2, true); } else { if (var2->_type == Variables::pointer && tok->tokAt(next + 1)->str() == "[") variables.readAliases(varid2); variables.read(varid2); } } else // not a local variable (or an unsupported local variable) { if (var1->_type == Variables::pointer && !dereference) { // check if variable declaration is in this scope if (var1->_scope == scope) variables.clearAliases(varid1); else { std::set::iterator assignment; // check for an assignment in this scope assignment = var1->_assignments.find(scope); // no other assignment in this scope if (assignment == var1->_assignments.end()) { /** * @todo determine if existing aliases should be discarded */ } // this assignment replaces the last assignment in this scope else { // aliased variables in a larger scope are not supported // remove all aliases variables.clearAliases(varid1); } } } } } var1->_assignments.insert(scope); } // check for alias to struct member // char c[10]; a.b = c; else if (Token::Match(tok->tokAt(-2), "%var% .")) { if (Token::Match(tok->tokAt(2), "%var%")) { unsigned int varid2 = tok->tokAt(2)->varId(); Variables::VariableUsage *var2 = variables.find(varid2); // struct member aliased to local variable if (var2 && (var2->_type == Variables::array || var2->_type == Variables::pointer)) { // erase aliased variable and all variables that alias it // to prevent false positives variables.eraseAll(varid2); } } } return next; } static bool nextIsStandardType(const Token *tok) { tok = tok->next(); if (tok->str() == "static") tok = tok->next(); return tok->isStandardType(); } static bool nextIsStandardTypeOrVoid(const Token *tok) { tok = tok->next(); if (tok->str() == "static") tok = tok->next(); if (tok->str() == "const") tok = tok->next(); return tok->isStandardType() || tok->str() == "void"; } void CheckOther::functionVariableUsage() { if (!_settings->_checkCodingStyle) return; // Parse all executing scopes.. const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase(); std::list::const_iterator scope; for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) { // only check functions if (scope->type != Scope::eFunction) continue; // First token for the current scope.. const Token *const tok1 = scope->classStart; // varId, usage {read, write, modified} Variables variables; // scopes ScopeInfo scopes; ScopeInfo *info = &scopes; unsigned int indentlevel = 0; for (const Token *tok = tok1; tok; tok = tok->next()) { if (tok->str() == "{") { // replace the head node when found if (indentlevel == 0) scopes = ScopeInfo(tok, NULL); // add the new scope else info = info->addChild(tok); ++indentlevel; } else if (tok->str() == "}") { --indentlevel; info = info->parent(); if (indentlevel == 0) break; } else if (Token::Match(tok, "struct|union|class {") || Token::Match(tok, "struct|union|class %type% {|:")) { while (tok->str() != "{") tok = tok->next(); tok = tok->link(); if (! tok) break; } if (Token::Match(tok, "[;{}] asm ( ) ;")) { variables.clear(); break; } // standard type declaration with possible initialization // int i; int j = 0; static int k; if (Token::Match(tok, "[;{}] static| %type% %var% ;|=") && nextIsStandardType(tok)) { tok = tok->next(); if (tok->str() == "static") tok = tok->next(); variables.addVar(tok->next(), Variables::standard, info, tok->tokAt(2)->str() == "=" || tok->previous()->str() == "static"); tok = tok->next(); } // standard type declaration and initialization using constructor // int i(0); static int j(0); else if (Token::Match(tok, "[;{}] static| %type% %var% ( %any% ) ;") && nextIsStandardType(tok)) { tok = tok->next(); if (tok->str() == "static") tok = tok->next(); variables.addVar(tok->next(), Variables::standard, info, true); // check if a local variable is used to initialize this variable if (tok->tokAt(3)->varId() > 0) variables.readAll(tok->tokAt(3)->varId()); tok = tok->tokAt(4); } // standard type declaration of array of with possible initialization // int i[10]; int j[2] = { 0, 1 }; static int k[2] = { 2, 3 }; else if (Token::Match(tok, "[;{}] static| const| %type% *| %var% [ %any% ] ;|=") && nextIsStandardType(tok)) { bool isStatic = false; tok = tok->next(); if (tok->str() == "static") { tok = tok->next(); isStatic = true; } if (tok->str() == "const") tok = tok->next(); if (tok->str() != "return" && tok->str() != "throw") { bool isPointer = bool(tok->strAt(1) == "*"); const Token * const nametok = tok->tokAt(isPointer ? 2 : 1); variables.addVar(nametok, isPointer ? Variables::pointerArray : Variables::array, info, nametok->tokAt(4)->str() == "=" || isStatic); // check for reading array size from local variable if (nametok->tokAt(2)->varId() != 0) variables.read(nametok->tokAt(2)->varId()); // look at initializers if (Token::simpleMatch(nametok->tokAt(4), "= {")) { tok = nametok->tokAt(6); while (tok->str() != "}") { if (Token::Match(tok, "%var%")) variables.read(tok->varId()); tok = tok->next(); } } else tok = nametok->tokAt(3); } } // pointer or reference declaration with possible initialization // int * i; int * j = 0; static int * k = 0; else if (Token::Match(tok, "[;{}] static| const| %type% *|& %var% ;|=")) { bool isStatic = false; tok = tok->next(); if (tok->str() == "static") { tok = tok->next(); isStatic = true; } if (tok->str() == "const") tok = tok->next(); if (tok->strAt(1) == "::") tok = tok->tokAt(2); if (tok->str() != "return" && tok->str() != "throw") { Variables::VariableType type; if (tok->next()->str() == "*") type = Variables::pointer; else type = Variables::reference; bool written = tok->tokAt(3)->str() == "="; variables.addVar(tok->tokAt(2), type, info, written || isStatic); int offset = 0; // check for assignment if (written) offset = doAssignment(variables, tok->tokAt(2), false, info); tok = tok->tokAt(2 + offset); } } // pointer to pointer declaration with possible initialization // int ** i; int ** j = 0; static int ** k = 0; else if (Token::Match(tok, "[;{}] static| const| %type% * * %var% ;|=")) { bool isStatic = false; tok = tok->next(); if (tok->str() == "static") { tok = tok->next(); isStatic = true; } if (tok->str() == "const") tok = tok->next(); if (tok->str() != "return") { bool written = tok->tokAt(4)->str() == "="; variables.addVar(tok->tokAt(3), Variables::pointerPointer, info, written || isStatic); int offset = 0; // check for assignment if (written) offset = doAssignment(variables, tok->tokAt(3), false, info); tok = tok->tokAt(3 + offset); } } // pointer or reference of struct or union declaration with possible initialization // struct s * i; struct s * j = 0; static struct s * k = 0; else if (Token::Match(tok, "[;{}] static| const| struct|union %type% *|& %var% ;|=")) { Variables::VariableType type; bool isStatic = false; tok = tok->next(); if (tok->str() == "static") { tok = tok->next(); isStatic = true; } if (tok->str() == "const") tok = tok->next(); if (tok->strAt(2) == "*") type = Variables::pointer; else type = Variables::reference; const bool written = tok->strAt(4) == "="; variables.addVar(tok->tokAt(3), type, info, written || isStatic); int offset = 0; // check for assignment if (written) offset = doAssignment(variables, tok->tokAt(3), false, info); tok = tok->tokAt(3 + offset); } // pointer or reference declaration with initialization using constructor // int * i(j); int * k(i); static int * l(i); else if (Token::Match(tok, "[;{}] static| const| %type% &|* %var% ( %any% ) ;") && nextIsStandardTypeOrVoid(tok)) { Variables::VariableType type; tok = tok->next(); if (tok->str() == "static") tok = tok->next(); if (tok->str() == "const") tok = tok->next(); if (tok->next()->str() == "*") type = Variables::pointer; else type = Variables::reference; unsigned int varid = 0; // check for aliased variable if (Token::Match(tok->tokAt(4), "%var%")) varid = tok->tokAt(4)->varId(); variables.addVar(tok->tokAt(2), type, info, true); // check if a local variable is used to initialize this variable if (varid > 0) { Variables::VariableUsage *var = variables.find(varid); if (type == Variables::pointer) { variables.use(tok->tokAt(4)->varId()); if (var && (var->_type == Variables::array || var->_type == Variables::pointer)) var->_aliases.insert(tok->varId()); } else { variables.readAll(tok->tokAt(4)->varId()); if (var) var->_aliases.insert(tok->varId()); } } tok = tok->tokAt(5); } // array of pointer or reference declaration with possible initialization // int * p[10]; int * q[10] = { 0 }; static int * * r[10] = { 0 }; else if (Token::Match(tok, "[;{}] static| const| %type% *|& %var% [ %any% ] ;|=")) { bool isStatic = false; tok = tok->next(); if (tok->str() == "static") { tok = tok->next(); isStatic = true; } if (tok->str() == "const") tok = tok->next(); if (tok->str() != "return") { variables.addVar(tok->tokAt(2), tok->next()->str() == "*" ? Variables::pointerArray : Variables::referenceArray, info, tok->tokAt(6)->str() == "=" || isStatic); // check for reading array size from local variable if (tok->tokAt(4)->varId() != 0) variables.read(tok->tokAt(4)->varId()); tok = tok->tokAt(5); } } // array of pointer or reference of struct or union declaration with possible initialization // struct S * p[10]; struct T * q[10] = { 0 }; static struct S * r[10] = { 0 }; else if (Token::Match(tok, "[;{}] static| const| struct|union %type% *|& %var% [ %any% ] ;|=")) { bool isStatic = false; tok = tok->next(); if (tok->str() == "static") { tok = tok->next(); isStatic = true; } if (tok->str() == "const") tok = tok->next(); variables.addVar(tok->tokAt(3), tok->tokAt(2)->str() == "*" ? Variables::pointerArray : Variables::referenceArray, info, tok->tokAt(7)->str() == "=" || isStatic); // check for reading array size from local variable if (tok->tokAt(5)->varId() != 0) variables.read(tok->tokAt(5)->varId()); tok = tok->tokAt(6); } // Freeing memory (not considered "using" the pointer if it was also allocated in this function) else if (Token::Match(tok, "free|g_free|kfree|vfree ( %var% )") || Token::Match(tok, "delete %var% ;") || Token::Match(tok, "delete [ ] %var% ;")) { unsigned int varid = 0; if (tok->str() != "delete") { varid = tok->tokAt(2)->varId(); tok = tok->tokAt(3); } else if (tok->strAt(1) == "[") { varid = tok->tokAt(3)->varId(); tok = tok->tokAt(4); } else { varid = tok->next()->varId(); tok = tok->tokAt(2); } Variables::VariableUsage *var = variables.find(varid); if (var && !var->_allocateMemory) { variables.readAll(varid); } } else if (Token::Match(tok, "return|throw %var%")) variables.readAll(tok->next()->varId()); // assignment else if (Token::Match(tok, "*| (| ++|--| %var% ++|--| )| =") || Token::Match(tok, "*| ( const| %type% *| ) %var% =")) { bool dereference = false; bool pre = false; bool post = false; if (tok->str() == "*") { dereference = true; tok = tok->next(); } if (Token::Match(tok, "( const| %type% *| ) %var% =")) tok = tok->link()->next(); else if (tok->str() == "(") tok = tok->next(); if (Token::Match(tok, "++|--")) { pre = true; tok = tok->next(); } if (Token::Match(tok->next(), "++|--")) post = true; const unsigned int varid1 = tok->varId(); const Token *start = tok; tok = tok->tokAt(doAssignment(variables, tok, dereference, info)); if (pre || post) variables.use(varid1); if (dereference) { variables.writeAliases(varid1); variables.read(varid1); } else { Variables::VariableUsage *var = variables.find(varid1); if (var && var->_type == Variables::reference) { variables.writeAliases(varid1); variables.read(varid1); } // Consider allocating memory separately because allocating/freeing alone does not constitute using the variable else if (var && var->_type == Variables::pointer && Token::Match(start, "%var% = new|malloc|calloc|g_malloc|kmalloc|vmalloc")) { bool allocate = true; if (start->strAt(2) == "new") { // is it a user defined type? if (!start->tokAt(3)->isStandardType()) { // lookup the type const Scope *type = symbolDatabase->findVariableType(&(*scope), start->tokAt(3)); // unknown type? if (!type) allocate = false; // has default constructor or // has members with unknown type or default constructor else if (type->needInitialization == Scope::False) allocate = false; } } if (allocate) variables.allocateMemory(varid1); else variables.write(varid1); } else if (varid1 && Token::Match(tok, "%varid% .", varid1)) { variables.use(varid1); } else { variables.write(varid1); } Variables::VariableUsage *var2 = variables.find(tok->varId()); if (var2) { if (var2->_type == Variables::reference) { variables.writeAliases(tok->varId()); variables.read(tok->varId()); } else if (tok->varId() != varid1 && Token::Match(tok, "%var% .")) variables.use(tok->varId()); else if (tok->varId() != varid1 && var2->_type == Variables::standard && tok->strAt(-1) != "&") variables.use(tok->varId()); } } const Token *equal = tok->next(); if (Token::Match(tok->next(), "[ %any% ]")) equal = tok->tokAt(4); // checked for chained assignments if (tok != start && equal->str() == "=") { Variables::VariableUsage *var = variables.find(tok->varId()); if (var && var->_type != Variables::reference) var->_read = true; tok = tok->previous(); } } // assignment else if (Token::Match(tok, "%var% [") && Token::Match(tok->next()->link(), "] =")) { unsigned int varid = tok->varId(); const Variables::VariableUsage *var = variables.find(varid); if (var) { // Consider allocating memory separately because allocating/freeing alone does not constitute using the variable if (var->_type == Variables::pointer && Token::Match(tok->next()->link(), "] = new|malloc|calloc|g_malloc|kmalloc|vmalloc")) { variables.allocateMemory(varid); } else if (var->_type == Variables::pointer || var->_type == Variables::reference) { variables.read(varid); variables.writeAliases(varid); } else variables.writeAll(varid); } } else if (Token::Match(tok, ">>|& %var%")) variables.use(tok->next()->varId()); // use = read + write else if (Token::Match(tok, "[;{}] %var% >>")) variables.use(tok->next()->varId()); // use = read + write // function parameter else if (Token::Match(tok, "[(,] %var% [")) variables.use(tok->next()->varId()); // use = read + write else if (Token::Match(tok, "[(,] %var% [,)]") && tok->previous()->str() != "*") variables.use(tok->next()->varId()); // use = read + write else if (Token::Match(tok, "[(,] (") && Token::Match(tok->next()->link(), ") %var% [,)]")) variables.use(tok->next()->link()->next()->varId()); // use = read + write // function else if (Token::Match(tok, "%var% (")) { variables.read(tok->varId()); if (Token::Match(tok->tokAt(2), "%var% =")) variables.read(tok->tokAt(2)->varId()); } else if (Token::Match(tok, "[{,] %var% [,}]")) variables.read(tok->next()->varId()); else if (Token::Match(tok, "%var% .")) variables.use(tok->varId()); // use = read + write else if ((Token::Match(tok, "[(=&!]") || tok->isExtendedOp()) && (Token::Match(tok->next(), "%var%") && !Token::Match(tok->next(), "true|false|new"))) variables.readAll(tok->next()->varId()); else if (Token::Match(tok, "%var%") && (tok->next()->str() == ")" || tok->next()->isExtendedOp())) variables.readAll(tok->varId()); else if (Token::Match(tok, "; %var% ;")) variables.readAll(tok->next()->varId()); if (Token::Match(tok, "++|-- %var%")) { if (tok->strAt(-1) != ";") variables.use(tok->next()->varId()); else variables.modified(tok->next()->varId()); } else if (Token::Match(tok, "%var% ++|--")) { if (tok->strAt(-1) != ";") variables.use(tok->varId()); else variables.modified(tok->varId()); } } // Check usage of all variables in the current scope.. Variables::VariableMap::const_iterator it; for (it = variables.varUsage().begin(); it != variables.varUsage().end(); ++it) { const Variables::VariableUsage &usage = it->second; const std::string &varname = usage._name->str(); // variable has been marked as unused so ignore it if (usage._name->isUnused()) continue; // skip things that are only partially implemented to prevent false positives if (usage._type == Variables::pointerPointer || usage._type == Variables::pointerArray || usage._type == Variables::referenceArray) continue; // variable has had memory allocated for it, but hasn't done // anything with that memory other than, perhaps, freeing it if (usage.unused() && !usage._modified && usage._allocateMemory) allocatedButUnusedVariableError(usage._name, varname); // variable has not been written, read, or modified else if (usage.unused() && !usage._modified) unusedVariableError(usage._name, varname); // variable has not been written but has been modified else if (usage._modified & !usage._write) unassignedVariableError(usage._name, varname); // variable has been written but not read else if (!usage._read && !usage._modified) unreadVariableError(usage._name, varname); // variable has been read but not written else if (!usage._write && !usage._allocateMemory) unassignedVariableError(usage._name, varname); } } } void CheckOther::unusedVariableError(const Token *tok, const std::string &varname) { reportError(tok, Severity::style, "unusedVariable", "Unused variable: " + varname); } void CheckOther::allocatedButUnusedVariableError(const Token *tok, const std::string &varname) { reportError(tok, Severity::style, "unusedAllocatedMemory", "Variable '" + varname + "' is allocated memory that is never used"); } void CheckOther::unreadVariableError(const Token *tok, const std::string &varname) { reportError(tok, Severity::style, "unreadVariable", "Variable '" + varname + "' is assigned a value that is never used"); } void CheckOther::unassignedVariableError(const Token *tok, const std::string &varname) { reportError(tok, Severity::style, "unassignedVariable", "Variable '" + varname + "' is not assigned a value"); } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Check scope of variables.. //--------------------------------------------------------------------------- void CheckOther::checkVariableScope() { if (!_settings->isEnabled("information")) return; const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase(); std::list::const_iterator scope; for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) { // only check functions if (scope->type != Scope::eFunction) continue; // Walk through all tokens.. int indentlevel = 0; for (const Token *tok = scope->classStart; tok; tok = tok->next()) { // Skip function local class and struct declarations.. if ((tok->str() == "class") || (tok->str() == "struct") || (tok->str() == "union")) { for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) { if (tok2->str() == "{") { tok = tok2->link(); break; } if (Token::Match(tok2, "[,);]")) { break; } } if (! tok) break; } else if (tok->str() == "{") { ++indentlevel; } else if (tok->str() == "}") { --indentlevel; if (indentlevel == 0) break;; } if (indentlevel > 0 && Token::Match(tok, "[{};]")) { // First token of statement.. const Token *tok1 = tok->next(); if (! tok1) continue; if ((tok1->str() == "return") || (tok1->str() == "throw") || (tok1->str() == "delete") || (tok1->str() == "goto") || (tok1->str() == "else")) continue; // Variable declaration? if (Token::Match(tok1, "%type% %var% ; %var% = %num% ;")) { // Tokenizer modify "int i = 0;" to "int i; i = 0;", // so to handle this situation we just skip // initialization (see ticket #272). const unsigned int firstVarId = tok1->next()->varId(); const unsigned int secondVarId = tok1->tokAt(3)->varId(); if (firstVarId > 0 && firstVarId == secondVarId) { lookupVar(tok1->tokAt(6), tok1->strAt(1)); } } else if (tok1->isStandardType() && Token::Match(tok1, "%type% %var% [;=]")) { lookupVar(tok1, tok1->strAt(1)); } } } } } //--------------------------------------------------------------------------- void CheckOther::lookupVar(const Token *tok1, const std::string &varname) { const Token *tok = tok1; // Skip the variable declaration.. while (tok && tok->str() != ";") tok = tok->next(); // Check if the variable is used in this indentlevel.. bool used1 = false; // used in one sub-scope -> reducable bool used2 = false; // used in more sub-scopes -> not reducable int indentlevel = 0; int parlevel = 0; bool for_or_while = false; // is sub-scope a "for/while/etc". anything that is not "if" while (tok) { if (tok->str() == "{") { if (tok->strAt(-1) == "=") { if (Token::findmatch(tok, varname.c_str(), tok->link())) { return; } tok = tok->link(); } else ++indentlevel; } else if (tok->str() == "}") { if (indentlevel == 0) break; --indentlevel; if (indentlevel == 0) { if (for_or_while && used2) return; used2 |= used1; used1 = false; } } else if (tok->str() == "(") { ++parlevel; } else if (tok->str() == ")") { --parlevel; } // Bail out if references are used else if (Token::simpleMatch(tok, (std::string("& ") + varname).c_str())) { return; } else if (tok->str() == varname) { if (indentlevel == 0) return; used1 = true; if (for_or_while && !Token::simpleMatch(tok->next(), "=")) used2 = true; if (used1 && used2) return; } else if (indentlevel == 0) { // %unknown% ( %any% ) { // If %unknown% is anything except if, we assume // that it is a for or while loop or a macro hiding either one if (Token::simpleMatch(tok->next(), "(") && Token::simpleMatch(tok->next()->link(), ") {")) { if (tok->str() != "if") for_or_while = true; } if (Token::simpleMatch(tok, "do {")) for_or_while = true; // possible unexpanded macro hiding for/while.. if (Token::Match(tok->previous(), "[;{}] %type% {")) { bool upper = true; for (unsigned int i = 0; i < tok->str().length(); ++i) { if (!std::isupper(tok->str()[i])) upper = false; } for_or_while |= upper; } if (parlevel == 0 && (tok->str() == ";")) for_or_while = false; } tok = tok->next(); } // Warning if this variable: // * not used in this indentlevel // * used in lower indentlevel if (used1 || used2) variableScopeError(tok1, varname); } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Check for constant function parameters //--------------------------------------------------------------------------- void CheckOther::checkConstantFunctionParameter() { if (!_settings->_checkCodingStyle) return; const SymbolDatabase * const symbolDatabase = _tokenizer->getSymbolDatabase(); for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "[,(] const std :: %type% %var% [,)]")) { passedByValueError(tok, tok->strAt(5)); } else if (Token::Match(tok, "[,(] const std :: %type% < %type% > %var% [,)]")) { passedByValueError(tok, tok->strAt(8)); } else if (Token::Match(tok, "[,(] const std :: %type% < std :: %type% > %var% [,)]")) { passedByValueError(tok, tok->strAt(10)); } else if (Token::Match(tok, "[,(] const std :: %type% < std :: %type% , std :: %type% > %var% [,)]")) { passedByValueError(tok, tok->strAt(14)); } else if (Token::Match(tok, "[,(] const std :: %type% < %type% , std :: %type% > %var% [,)]")) { passedByValueError(tok, tok->strAt(12)); } else if (Token::Match(tok, "[,(] const std :: %type% < std :: %type% , %type% > %var% [,)]")) { passedByValueError(tok, tok->strAt(12)); } else if (Token::Match(tok, "[,(] const std :: %type% < %type% , %type% > %var% [,)]")) { passedByValueError(tok, tok->strAt(10)); } else if (Token::Match(tok, "[,(] const %type% %var% [,)]")) { // Check if type is a struct or class. if (symbolDatabase->isClassOrStruct(tok->strAt(2))) { passedByValueError(tok, tok->strAt(3)); } } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Check that all struct members are used //--------------------------------------------------------------------------- void CheckOther::checkStructMemberUsage() { if (!_settings->_checkCodingStyle) return; std::string structname; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->fileIndex() != 0) continue; if (Token::Match(tok, "struct|union %type% {")) { structname.clear(); if (Token::simpleMatch(tok->previous(), "extern")) continue; if ((!tok->previous() || Token::simpleMatch(tok->previous(), ";")) && Token::Match(tok->tokAt(2)->link(), ("} ; " + tok->strAt(1) + " %var% ;").c_str())) continue; structname = tok->strAt(1); // Bail out if struct/union contain any functions for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) { if (tok2->str() == "(") { structname.clear(); break; } if (tok2->str() == "}") break; } // bail out if struct is inherited if (!structname.empty() && Token::findmatch(tok, (",|private|protected|public " + structname).c_str())) structname.clear(); // Bail out if some data is casted to struct.. const std::string s("( struct| " + tok->next()->str() + " * ) & %var% ["); if (Token::findmatch(tok, s.c_str())) structname.clear(); // Try to prevent false positives when struct members are not used directly. if (Token::findmatch(tok, (structname + " *").c_str())) structname.clear(); else if (Token::findmatch(tok, (structname + " %type% *").c_str())) structname = ""; } if (tok->str() == "}") structname.clear(); if (!structname.empty() && Token::Match(tok, "[{;]")) { // Declaring struct variable.. std::string varname; // declaring a POD variable? if (!tok->next()->isStandardType()) continue; if (Token::Match(tok->next(), "%type% %var% [;[]")) varname = tok->strAt(2); else if (Token::Match(tok->next(), "%type% %type% %var% [;[]")) varname = tok->strAt(3); else if (Token::Match(tok->next(), "%type% * %var% [;[]")) varname = tok->strAt(3); else if (Token::Match(tok->next(), "%type% %type% * %var% [;[]")) varname = tok->strAt(4); else continue; // Check if the struct variable is used anywhere in the file const std::string usagePattern(". " + varname); bool used = false; for (const Token *tok2 = _tokenizer->tokens(); tok2; tok2 = tok2->next()) { if (Token::simpleMatch(tok2, usagePattern.c_str())) { used = true; break; } } if (! used) { unusedStructMemberError(tok->next(), structname, varname); } } } } //--------------------------------------------------------------------------- // Check usage of char variables.. //--------------------------------------------------------------------------- void CheckOther::checkCharVariable() { if (!_settings->_checkCodingStyle) return; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { // Declaring the variable.. if (Token::Match(tok, "[{};(,] char %var% [;=,)]")) { // Check for unsigned char if (tok->tokAt(1)->isUnsigned()) continue; // Set tok to point to the variable name tok = tok->tokAt(2); if (tok->str() == "char") tok = tok->next(); // Check usage of char variable.. int indentlevel = 0; for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next()) { if (tok2->str() == "{") ++indentlevel; else if (tok2->str() == "}") { --indentlevel; if (indentlevel <= 0) break; } else if (tok2->str() == "return") continue; std::string temp = "%var% [ " + tok->str() + " ]"; if ((tok2->str() != ".") && Token::Match(tok2->next(), temp.c_str())) { charArrayIndexError(tok2->next()); break; } if (Token::Match(tok2, "[;{}] %var% = %any% [&|] %any% ;")) { // is the char variable used in the calculation? if (tok2->tokAt(3)->varId() != tok->varId() && tok2->tokAt(5)->varId() != tok->varId()) continue; // it's ok with a bitwise and where the other operand is 0xff or less.. if (std::string(tok2->strAt(4)) == "&") { if (tok2->tokAt(3)->isNumber() && MathLib::isGreater("0x100", tok2->strAt(3))) continue; if (tok2->tokAt(5)->isNumber() && MathLib::isGreater("0x100", tok2->strAt(5))) continue; } // is the result stored in a short|int|long? if (!Token::findmatch(_tokenizer->tokens(), "short|int|long %varid%", tok2->next()->varId())) continue; // This is an error.. charBitOpError(tok2); break; } } } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Incomplete statement.. //--------------------------------------------------------------------------- void CheckOther::checkIncompleteStatement() { if (!_settings->_checkCodingStyle) return; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->str() == "(") { tok = tok->link(); if (Token::simpleMatch(tok, ") {") && Token::simpleMatch(tok->next()->link(), "} ;")) tok = tok->next()->link(); } else if (Token::simpleMatch(tok, "= {")) tok = tok->next()->link(); else if (tok->str() == "{" && Token::Match(tok->tokAt(-2), "%type% %var%")) tok = tok->link(); else if (Token::Match(tok, "[;{}] %str%") || Token::Match(tok, "[;{}] %num%")) { // bailout if there is a "? :" in this statement bool bailout = false; for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) { if (tok2->str() == "?") bailout = true; else if (tok2->str() == ";") break; } if (bailout) continue; constStatementError(tok->next(), tok->next()->isNumber() ? "numeric" : "string"); } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // str plus char //--------------------------------------------------------------------------- void CheckOther::strPlusChar() { // Don't use this check for Java and C# programs.. if (_tokenizer->isJavaOrCSharp()) { return; } bool charVars[10000] = {0}; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { // Declaring char variable.. if (Token::Match(tok, "char|int|short %var% [;=]")) { unsigned int varid = tok->next()->varId(); if (varid > 0 && varid < 10000) charVars[varid] = true; } // else if (Token::Match(tok, "[=(] %str% + %any%")) { // char constant.. const std::string s = tok->strAt(3); if (s[0] == '\'') strPlusChar(tok->next()); // char variable.. unsigned int varid = tok->tokAt(3)->varId(); if (varid > 0 && varid < 10000 && charVars[varid]) strPlusChar(tok->next()); } } } void CheckOther::checkZeroDivision() { for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "/ %num%") && MathLib::isInt(tok->next()->str()) && MathLib::toLongNumber(tok->next()->str()) == 0L) { zerodivError(tok); } else if (Token::Match(tok, "div|ldiv|lldiv|imaxdiv ( %num% , %num% )") && MathLib::isInt(tok->tokAt(4)->str()) && MathLib::toLongNumber(tok->tokAt(4)->str()) == 0L) { zerodivError(tok); } } } void CheckOther::checkMathFunctions() { for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { // case log(-2) if (tok->varId() == 0 && Token::Match(tok, "log|log10 ( %num% )") && MathLib::isNegative(tok->tokAt(2)->str()) && MathLib::isInt(tok->tokAt(2)->str()) && MathLib::toLongNumber(tok->tokAt(2)->str()) <= 0) { mathfunctionCallError(tok); } // case log(-2.0) else if (tok->varId() == 0 && Token::Match(tok, "log|log10 ( %num% )") && MathLib::isNegative(tok->tokAt(2)->str()) && MathLib::isFloat(tok->tokAt(2)->str()) && MathLib::toDoubleNumber(tok->tokAt(2)->str()) <= 0.) { mathfunctionCallError(tok); } // case log(0.0) else if (tok->varId() == 0 && Token::Match(tok, "log|log10 ( %num% )") && !MathLib::isNegative(tok->tokAt(2)->str()) && MathLib::isFloat(tok->tokAt(2)->str()) && MathLib::toDoubleNumber(tok->tokAt(2)->str()) <= 0.) { mathfunctionCallError(tok); } // case log(0) else if (tok->varId() == 0 && Token::Match(tok, "log|log10 ( %num% )") && !MathLib::isNegative(tok->tokAt(2)->str()) && MathLib::isInt(tok->tokAt(2)->str()) && MathLib::toLongNumber(tok->tokAt(2)->str()) <= 0) { mathfunctionCallError(tok); } // acos( x ), asin( x ) where x is defined for intervall [-1,+1], but not beyound else if (tok->varId() == 0 && Token::Match(tok, "acos|asin ( %num% )") && std::fabs(MathLib::toDoubleNumber(tok->tokAt(2)->str())) > 1.0) { mathfunctionCallError(tok); } // sqrt( x ): if x is negative the result is undefined else if (tok->varId() == 0 && Token::Match(tok, "sqrt ( %num% )") && MathLib::isNegative(tok->tokAt(2)->str())) { mathfunctionCallError(tok); } // atan2 ( x , y): x and y can not be zero, because this is mathematically not defined else if (tok->varId() == 0 && Token::Match(tok, "atan2 ( %num% , %num% )") && MathLib::isNullValue(tok->tokAt(2)->str()) && MathLib::isNullValue(tok->tokAt(4)->str())) { mathfunctionCallError(tok, 2); } // fmod ( x , y) If y is zero, then either a range error will occur or the function will return zero (implementation-defined). else if (tok->varId() == 0 && Token::Match(tok, "fmod ( %num% , %num% )") && MathLib::isNullValue(tok->tokAt(4)->str())) { mathfunctionCallError(tok, 2); } // pow ( x , y) If x is zero, and y is negative --> division by zero else if (tok->varId() == 0 && Token::Match(tok, "pow ( %num% , %num% )") && MathLib::isNullValue(tok->tokAt(2)->str()) && MathLib::isNegative(tok->tokAt(4)->str())) { mathfunctionCallError(tok, 2); } } } /** Is there a function with given name? */ static bool isFunction(const std::string &name, const Token *startToken) { const std::string pattern1(name + " ("); for (const Token *tok = startToken; tok; tok = tok->next()) { // skip executable scopes etc if (tok->str() == "(") { tok = tok->link(); if (Token::simpleMatch(tok, ") {")) tok = tok->next()->link(); else if (Token::simpleMatch(tok, ") const {")) tok = tok->tokAt(2)->link(); } // function declaration/implementation found if ((tok->str() == "*" || (tok->isName() && tok->str().find(":") ==std::string::npos)) && Token::simpleMatch(tok->next(), pattern1.c_str())) return true; } return false; } void CheckOther::checkMisusedScopedObject() { // Skip this check for .c files { const std::string fname = _tokenizer->getFiles()->at(0); const std::string ext = fname.substr(fname.rfind(".")); if (ext == ".c" || ext == ".C") return; } const SymbolDatabase * const symbolDatabase = _tokenizer->getSymbolDatabase(); std::list::const_iterator scope; for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) { // only check functions if (scope->type != Scope::eFunction) continue; unsigned int depth = 0; for (const Token *tok = scope->classStart; tok; tok = tok->next()) { if (tok->str() == "{") { ++depth; } else if (tok->str() == "}") { --depth; if (depth == 0) break; } if (Token::Match(tok, "[;{}] %var% (") && Token::simpleMatch(tok->tokAt(2)->link(), ") ;") && symbolDatabase->isClassOrStruct(tok->next()->str()) && !isFunction(tok->next()->str(), _tokenizer->tokens())) { tok = tok->next(); misusedScopeObjectError(tok, tok->str()); tok = tok->next(); } } } } void CheckOther::checkIncorrectStringCompare() { for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, ". substr ( %any% , %num% ) ==|!= %str%")) { size_t clen = MathLib::toLongNumber(tok->tokAt(5)->str()); size_t slen = Token::getStrLength(tok->tokAt(8)); if (clen != slen) { incorrectStringCompareError(tok->next(), "substr", tok->tokAt(8)->str(), tok->tokAt(5)->str()); } } if (Token::Match(tok, "%str% ==|!= %var% . substr ( %any% , %num% )")) { size_t clen = MathLib::toLongNumber(tok->tokAt(8)->str()); size_t slen = Token::getStrLength(tok); if (clen != slen) { incorrectStringCompareError(tok->next(), "substr", tok->str(), tok->tokAt(8)->str()); } } } } //----------------------------------------------------------------------------- // check for duplicate expressions in if statements // if (a) { } else if (a) { } //----------------------------------------------------------------------------- static const std::string stringifyTokens(const Token *start, const Token *end) { const Token *tok = start; std::string stringified = tok->str(); while (tok && tok->next() && tok != end) { tok = tok->next(); stringified.append(" "); stringified.append(tok->str()); } return stringified; } static bool expressionHasSideEffects(const Token *first, const Token *last) { for (const Token *tok = first; tok != last->next(); tok = tok->next()) { // check for assignment if (tok->isAssignmentOp()) return true; // check for inc/dec else if (Token::Match(tok, "++|--")) return true; // check for function call else if (Token::Match(tok, "%var% (") && !(Token::Match(tok, "c_str|string") || tok->isStandardType())) return true; } return false; } void CheckOther::checkDuplicateIf() { if (!_settings->_checkCodingStyle) return; const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase(); std::list::const_iterator scope; for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) { // only check functions if (scope->type != Scope::eFunction) continue; // check all the code in the function for if (...) and else if (...) statements for (const Token *tok = scope->classStart; tok && tok != scope->classStart->link(); tok = tok->next()) { if (Token::Match(tok, "if (") && tok->strAt(-1) != "else" && Token::Match(tok->next()->link(), ") {")) { std::map expressionMap; // get the expression from the token stream std::string expression = stringifyTokens(tok->tokAt(2), tok->next()->link()->previous()); // save the expression and its location expressionMap.insert(std::make_pair(expression, tok)); // find the next else if (...) statement const Token *tok1 = tok->next()->link()->next()->link(); // check all the else if (...) statements while (Token::Match(tok1, "} else if (") && Token::Match(tok1->tokAt(3)->link(), ") {")) { // get the expression from the token stream expression = stringifyTokens(tok1->tokAt(4), tok1->tokAt(3)->link()->previous()); // try to look up the expression to check for duplicates std::map::iterator it = expressionMap.find(expression); // found a duplicate if (it != expressionMap.end()) { // check for expressions that have side effects and ignore them if (!expressionHasSideEffects(tok1->tokAt(4), tok1->tokAt(3)->link()->previous())) duplicateIfError(it->second, tok1->next()); } // not a duplicate expression so save it and its location else expressionMap.insert(std::make_pair(expression, tok1->next())); // find the next else if (...) statement tok1 = tok1->tokAt(3)->link()->next()->link(); } tok = tok->next()->link()->next(); } } } } void CheckOther::duplicateIfError(const Token *tok1, const Token *tok2) { std::list toks; toks.push_back(tok2); toks.push_back(tok1); reportError(toks, Severity::style, "duplicateIf", "Found duplicate if expressions.\n" "Finding the same expression more than once is suspicious and might indicate " "a cut and paste or logic error. Please examine this code carefully to determine " "if it is correct."); } //----------------------------------------------------------------------------- // check for duplicate code in if and else branches // if (a) { b = true; } else { b = true; } //----------------------------------------------------------------------------- void CheckOther::checkDuplicateBranch() { if (!_settings->_checkCodingStyle) return; const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase(); std::list::const_iterator scope; for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) { // only check functions if (scope->type != Scope::eFunction) continue; // check all the code in the function for if (..) else for (const Token *tok = scope->classStart; tok && tok != scope->classStart->link(); tok = tok->next()) { if (Token::Match(tok, "if (") && tok->strAt(-1) != "else" && Token::Match(tok->next()->link(), ") {") && Token::Match(tok->next()->link()->next()->link(), "} else {")) { // save if branch code std::string branch1 = stringifyTokens(tok->next()->link()->tokAt(2), tok->next()->link()->next()->link()->previous()); // find else branch const Token *tok1 = tok->next()->link()->next()->link(); // save else branch code std::string branch2 = stringifyTokens(tok1->tokAt(3), tok1->tokAt(2)->link()->previous()); // check for duplicates if (branch1 == branch2) duplicateBranchError(tok, tok1->tokAt(2)); tok = tok->next()->link()->next(); } } } } void CheckOther::duplicateBranchError(const Token *tok1, const Token *tok2) { std::list toks; toks.push_back(tok2); toks.push_back(tok1); reportError(toks, Severity::style, "duplicateBranch", "Found duplicate branches for if and else.\n" "Finding the same code for an if branch and an else branch is suspicious and " "might indicate a cut and paste or logic error. Please examine this code " "carefully to determine if it is correct."); } //----------------------------------------------------------------------------- void CheckOther::cstyleCastError(const Token *tok) { reportError(tok, Severity::style, "cstyleCast", "C-style pointer casting"); } void CheckOther::dangerousUsageStrtolError(const Token *tok) { reportError(tok, Severity::error, "dangerousUsageStrtol", "Invalid radix in call to strtol or strtoul. Must be 0 or 2-36"); } void CheckOther::sprintfOverlappingDataError(const Token *tok, const std::string &varname) { reportError(tok, Severity::error, "sprintfOverlappingData", "Undefined behavior: variable is used as parameter and destination in s[n]printf().\n" "The variable '" + varname + "' is used both as a parameter and as a destination in " "s[n]printf(). The origin and destination buffers overlap. Quote from glibc (C-library) " "documentation (http://www.gnu.org/software/libc/manual/html_mono/libc.html#Formatted-Output-Functions): " "'If copying takes place between objects that overlap as a result of a call " "to sprintf() or snprintf(), the results are undefined.'"); } void CheckOther::udivError(const Token *tok) { reportError(tok, Severity::error, "udivError", "Unsigned division. The result will be wrong."); } void CheckOther::unusedStructMemberError(const Token *tok, const std::string &structname, const std::string &varname) { reportError(tok, Severity::style, "unusedStructMember", "struct or union member '" + structname + "::" + varname + "' is never used"); } void CheckOther::passedByValueError(const Token *tok, const std::string &parname) { reportError(tok, Severity::performance, "passedByValue", "Function parameter '" + parname + "' should be passed by reference.\n" "Parameter '" + parname + "' is passed as a value. It could be passed " "as a (const) reference which is usually faster and recommended in C++."); } void CheckOther::constStatementError(const Token *tok, const std::string &type) { reportError(tok, Severity::warning, "constStatement", "Redundant code: Found a statement that begins with " + type + " constant"); } void CheckOther::charArrayIndexError(const Token *tok) { reportError(tok, Severity::warning, "charArrayIndex", "Warning - using char variable as array index"); } void CheckOther::charBitOpError(const Token *tok) { reportError(tok, Severity::warning, "charBitOp", "Warning - using char variable in bit operation"); } void CheckOther::variableScopeError(const Token *tok, const std::string &varname) { reportError(tok, Severity::information, "variableScope", "The scope of the variable '" + varname + "' can be reduced\n" "The scope of the variable '" + varname + "' can be reduced. Warning: It can be unsafe " "to fix this message. Be careful. Especially when there are inner loops. Here is an " "example where cppcheck will write that the scope for 'i' can be reduced:\n" "void f(int x)\n" "{\n" " int i = 0;\n" " if (x) {\n" " // it's safe to move 'int i = 0' here\n" " for (int n = 0; n < 10; ++n) {\n" " // it is possible but not safe to move 'int i = 0' here\n" " do_something(&i);\n" " }\n" " }\n" "}\n" "When you see this message it is always safe to reduce the variable scope 1 level."); } void CheckOther::conditionAlwaysTrueFalse(const Token *tok, const std::string &truefalse) { reportError(tok, Severity::style, "conditionAlwaysTrueFalse", "Condition is always " + truefalse); } void CheckOther::strPlusChar(const Token *tok) { reportError(tok, Severity::error, "strPlusChar", "Unusual pointer arithmetic"); } void CheckOther::zerodivError(const Token *tok) { reportError(tok, Severity::error, "zerodiv", "Division by zero"); } void CheckOther::mathfunctionCallError(const Token *tok, const unsigned int numParam) { if (tok) { if (numParam == 1) reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->tokAt(2)->str() + " to " + tok->str() + "() leads to undefined result"); else if (numParam == 2) reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->tokAt(2)->str() + " and " + tok->tokAt(4)->str() + " to " + tok->str() + "() leads to undefined result"); } else reportError(tok, Severity::error, "wrongmathcall", "Passing value " " to " "() leads to undefined result"); } void CheckOther::fflushOnInputStreamError(const Token *tok, const std::string &varname) { reportError(tok, Severity::error, "fflushOnInputStream", "fflush() called on input stream \"" + varname + "\" may result in undefined behaviour"); } void CheckOther::sizeofsizeof() { if (!_settings->_checkCodingStyle) return; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "sizeof (| sizeof")) { sizeofsizeofError(tok); tok = tok->next(); } } } void CheckOther::sizeofsizeofError(const Token *tok) { reportError(tok, Severity::warning, "sizeofsizeof", "Calling sizeof for 'sizeof'.\n" "Calling sizeof for 'sizeof looks like a suspicious code and " "most likely there should be just one 'sizeof'. The current " "code is equivalent to 'sizeof(size_t)'"); } void CheckOther::sizeofCalculation() { if (!_settings->_checkCodingStyle) return; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::simpleMatch(tok, "sizeof (")) { unsigned int parlevel = 0; for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) { if (tok2->str() == "(") ++parlevel; else if (tok2->str() == ")") { if (parlevel <= 1) break; --parlevel; } else if (Token::Match(tok2, "+|/")) { sizeofCalculationError(tok2); break; } } } } } void CheckOther::sizeofCalculationError(const Token *tok) { reportError(tok, Severity::warning, "sizeofCalculation", "Found calculation inside sizeof()"); } void CheckOther::redundantAssignmentInSwitchError(const Token *tok, const std::string &varname) { reportError(tok, Severity::warning, "redundantAssignInSwitch", "Redundant assignment of \"" + varname + "\" in switch"); } void CheckOther::switchCaseFallThrough(const Token *tok) { reportError(tok, Severity::style, "switchCaseFallThrough", "Switch falls through case without comment"); } void CheckOther::selfAssignmentError(const Token *tok, const std::string &varname) { reportError(tok, Severity::warning, "selfAssignment", "Redundant assignment of \"" + varname + "\" to itself"); } void CheckOther::assignmentInAssertError(const Token *tok, const std::string &varname) { reportError(tok, Severity::warning, "assignmentInAssert", "Assert statement modifies '" + varname + "'.\n" "Variable '" + varname + "' is modified insert assert statement. " "Assert statements are removed from release builds so the code inside " "assert statement is not run. If the code is needed also in release " "builds this is a bug."); } void CheckOther::incorrectLogicOperatorError(const Token *tok) { reportError(tok, Severity::warning, "incorrectLogicOperator", "Mutual exclusion over || always evaluates to true. Did you intend to use && instead?"); } void CheckOther::misusedScopeObjectError(const Token *tok, const std::string& varname) { reportError(tok, Severity::error, "unusedScopedObject", "instance of \"" + varname + "\" object destroyed immediately"); } void CheckOther::catchExceptionByValueError(const Token *tok) { reportError(tok, Severity::style, "catchExceptionByValue", "Exception should be caught by reference.\n" "The exception is caught as a value. It could be caught " "as a (const) reference which is usually recommended in C++."); } void CheckOther::memsetZeroBytesError(const Token *tok, const std::string &varname) { const std::string summary("memset() called to fill 0 bytes of \'" + varname + "\'"); const std::string verbose(summary + ". Second and third arguments might be inverted."); reportError(tok, Severity::warning, "memsetZeroBytes", summary + "\n" + verbose); } void CheckOther::incorrectStringCompareError(const Token *tok, const std::string& func, const std::string &string, const std::string &len) { reportError(tok, Severity::warning, "incorrectStringCompare", "String literal " + string + " doesn't match length argument for " + func + "(" + len + ")."); } void CheckOther::comparisonOfBoolWithIntError(const Token *tok, const std::string &varname) { reportError(tok, Severity::warning, "comparisonOfBoolWithInt", "Comparison of a boolean with a non-zero integer\n" "The expression \"!" + varname + "\" is of type 'bool' but is compared against a non-zero 'int'."); }