/* * cppcheck - c/c++ syntax checking * Copyright (C) 2007-2009 Daniel Marjamäki, Reijo Tomperi, Nicolas Le Cam * * 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 #include #include // <- atoi #include #include //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Warning on C-Style casts.. p = (kalle *)foo; //--------------------------------------------------------------------------- CheckOther::CheckOther(const Tokenizer *tokenizer, ErrorLogger *errorLogger) { _tokenizer = tokenizer; _errorLogger = errorLogger; } CheckOther::~CheckOther() { } void CheckOther::WarningOldStylePointerCast() { for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { // Old style pointer casting.. if (!Token::Match(tok, "( %type% * ) %var%")) continue; // Is "type" a class? const std::string pattern("class " + tok->next()->str()); if (!Token::findmatch(_tokenizer->tokens(), pattern.c_str())) continue; _errorLogger->reportErr(ErrorMessage::cstyleCast(_tokenizer, tok)); } } //--------------------------------------------------------------------------- // Redundant code.. //--------------------------------------------------------------------------- void CheckOther::WarningRedundantCode() { // if (p) delete p for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->str() != "if") continue; const char *varname1 = NULL; const Token *tok2 = NULL; if (Token::Match(tok, "if ( %var% )")) { varname1 = tok->strAt(2); tok2 = tok->tokAt(4); } else if (Token::Match(tok, "if ( %var% != NULL )")) { varname1 = tok->strAt(2); tok2 = tok->tokAt(6); } if (varname1 == NULL || tok2 == NULL) continue; bool err = false; if (tok2->str() == "{") { tok2 = tok2->next(); if (Token::Match(tok2, "delete %var% ; }")) { err = (strcmp(tok2->strAt(1), varname1) == 0); } else if (Token::Match(tok2, "delete [ ] %var% ; }")) { err = (strcmp(tok2->strAt(1), varname1) == 0); } else if (Token::Match(tok2, "free ( %var% ) ; }")) { err = (strcmp(tok2->strAt(2), varname1) == 0); } else if (Token::Match(tok2, "kfree ( %var% ) ; }")) { err = (strcmp(tok2->strAt(2), varname1) == 0); } } else { if (Token::Match(tok2, "delete %var% ;")) { err = (strcmp(tok2->strAt(1), varname1) == 0); } else if (Token::Match(tok2, "delete [ ] %var% ;")) { err = (strcmp(tok2->strAt(1), varname1) == 0); } else if (Token::Match(tok2, "free ( %var% ) ;")) { err = (strcmp(tok2->strAt(2), varname1) == 0); } else if (Token::Match(tok2, "kfree ( %var% ) ;")) { err = (strcmp(tok2->strAt(2), varname1) == 0); } } if (err) { _errorLogger->reportErr(ErrorMessage::redundantIfDelete0(_tokenizer, tok)); } } // Redundant condition // if (haystack.find(needle) != haystack.end()) // haystack.remove(needle); redundantCondition2(); } //--------------------------------------------------------------------------- void CheckOther::redundantCondition2() { const char pattern[] = "if ( %var% . find ( %any% ) != %var% . end ( ) ) " "{|{|" " %var% . remove ( %any% ) ; " "}|}|"; const Token *tok = Token::findmatch(_tokenizer->tokens(), pattern); while (tok) { bool b = Token::Match(tok->tokAt(15), "{"); // Get tokens for the fields %var% and %any% const Token *var1 = tok->tokAt(2); const Token *any1 = tok->tokAt(6); const Token *var2 = tok->tokAt(9); const Token *var3 = tok->tokAt(b ? 16 : 15); const Token *any2 = tok->tokAt(b ? 20 : 19); // Check if all the "%var%" fields are the same and if all the "%any%" are the same.. if (var1->str() == var2->str() && var2->str() == var3->str() && any1->str() == any2->str()) { _errorLogger->reportErr(ErrorMessage::redundantIfRemove(_tokenizer, tok)); } tok = Token::findmatch(tok->next(), pattern); } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // if (condition) .... //--------------------------------------------------------------------------- void CheckOther::WarningIf() { // Search for 'if (condition);' for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (!Token::simpleMatch(tok, "if (")) continue; // Search for the end paranthesis for the condition.. int parlevel = 0; for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next()) { if (tok2->str() == "(") ++parlevel; else if (tok2->str() == ")") { --parlevel; if (parlevel <= 0) { if (Token::Match(tok2, ") ; !!else")) { std::ostringstream ostr; ostr << _tokenizer->fileLine(tok) << ": Found \"if (condition);\""; _errorLogger->reportErr(ostr.str()); } break; } } } } // Search for 'a=b; if (a==b)' for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { // Begin statement? if (! Token::Match(tok, "[;{}]")) continue; tok = tok->next(); if (! tok) break; if (!Token::Match(tok, "%var% = %var% ; if ( %var%")) continue; if (strcmp(tok->strAt(9), ")") != 0) continue; // var1 = var2 ; if ( var3 cond var4 ) const char *var1 = tok->strAt(0); const char *var2 = tok->strAt(2); const char *var3 = tok->strAt(6); const char *cond = tok->strAt(7); const char *var4 = tok->strAt(8); // Check that var3 is equal with either var1 or var2 if (strcmp(var1, var3) && strcmp(var2, var3)) continue; // Check that var4 is equal with either var1 or var2 if (strcmp(var1, var4) && strcmp(var2, var4)) continue; // Check that there is a condition.. const char *p[6] = {"==", "<=", ">=", "!=", "<", ">"}; bool iscond = false; for (int i = 0; i < 6; i++) { if (strcmp(cond, p[i]) == 0) { iscond = true; break; } } if (!iscond) break; // we found the error. Report. std::ostringstream ostr; ostr << _tokenizer->fileLine(tok->tokAt(4)) << ": The condition is always "; for (int i = 0; i < 6; i++) { if (strcmp(cond, p[i]) == 0) ostr << (i < 3 ? "True" : "False"); } _errorLogger->reportErr(ostr.str()); } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // 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 ((tok->str() != "strtol") && (tok->str() != "strtoul")) continue; // Locate the third parameter of the function call.. int parlevel = 0; int param = 1; for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next()) { if (Token::Match(tok2, "(")) ++parlevel; else if (Token::Match(tok2, ")")) --parlevel; else if (parlevel == 1 && Token::Match(tok2, ",")) { ++param; if (param == 3) { if (Token::Match(tok2, ", %num% )")) { int radix = atoi(tok2->strAt(1)); if (!(radix == 0 || (radix >= 2 && radix <= 36))) { _errorLogger->reportErr(ErrorMessage::dangerousUsageStrtol(_tokenizer, 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? unsigned 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 && tok2->varId() == varid) { std::ostringstream ostr; ostr << _tokenizer->fileLine(tok2) << ": Overlapping data buffer " << tok2->str(); _errorLogger->reportErr(ostr.str()); break; } } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Assignment in condition //--------------------------------------------------------------------------- void CheckOther::CheckIfAssignment() { for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "if ( %var% = %num% )") || Token::Match(tok, "if ( %var% = %str% )") || Token::Match(tok, "if ( %var% = %var% )")) { std::ostringstream ostr; ostr << _tokenizer->fileLine(tok) << ": Possible bug. Should it be '==' instead of '='?"; _errorLogger->reportErr(ostr.str()); } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Check for unsigned divisions //--------------------------------------------------------------------------- void CheckOther::CheckUnsignedDivision() { // 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% [;=,)]")) { const char *type = tok->strAt(1); if (strcmp(type, "char") == 0 || strcmp(type, "short") == 0 || strcmp(type, "int") == 0) varsign[tok->strAt(2)] = 's'; } else if (Token::Match(tok, "[{};(,] unsigned %type% %var% [;=,)]")) varsign[tok->strAt(3)] = 'u'; else if (!Token::Match(tok, "[).]") && Token::Match(tok->next(), "%var% / %var%")) { const char *varname1 = tok->strAt(1); const char *varname2 = tok->strAt(3); char sign1 = varsign[varname1]; char sign2 = varsign[varname2]; if (sign1 && sign2 && sign1 != sign2) { // One of the operands are signed, the other is unsigned.. std::ostringstream ostr; ostr << _tokenizer->fileLine(tok->next()) << ": Warning: Division with signed and unsigned operators"; _errorLogger->reportErr(ostr.str()); } } else if (!Token::Match(tok, "[).]") && Token::Match(tok->next(), "%var% / - %num%")) { const char *varname1 = tok->strAt(1); char sign1 = varsign[varname1]; if (sign1 == 'u') { std::ostringstream ostr; ostr << _tokenizer->fileLine(tok->next()) << ": Unsigned division. The result will be wrong."; _errorLogger->reportErr(ostr.str()); } } else if (Token::Match(tok, "[([=*/+-] - %num% / %var%")) { const char *varname2 = tok->strAt(4); char sign2 = varsign[varname2]; if (sign2 == 'u') { std::ostringstream ostr; ostr << _tokenizer->fileLine(tok->next()) << ": Unsigned division. The result will be wrong."; _errorLogger->reportErr(ostr.str()); } } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Check scope of variables.. //--------------------------------------------------------------------------- void CheckOther::CheckVariableScope() { // Walk through all tokens.. bool func = false; int indentlevel = 0; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { // Skip class and struct declarations.. if ((tok->str() == "class") || (tok->str() == "struct")) { for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) { if (tok2->str() == "{") { int indentlevel2 = 0; for (tok = tok2; tok; tok = tok->next()) { if (tok->str() == "{") { ++indentlevel2; } if (tok->str() == "}") { --indentlevel2; if (indentlevel2 <= 0) { tok = tok->next(); break; } } } break; } if (Token::Match(tok2, "[,);]")) { break; } } if (! tok) break; } if (tok->str() == "{") { ++indentlevel; } if (tok->str() == "}") { --indentlevel; if (indentlevel == 0) func = false; } if (indentlevel == 0 && Token::Match(tok, ") {")) { func = true; } if (indentlevel > 0 && func && Token::Match(tok, "[{};]")) { // First token of statement.. const Token *tok1 = tok->next(); if (! tok1) continue; if ((tok1->str() == "return") || (tok1->str() == "delete") || (tok1->str() == "goto") || (tok1->str() == "else")) continue; // Variable declaration? if (Token::Match(tok1, "%var% %var% ;") || Token::Match(tok1, "%var% %var% =")) { CheckVariableScope_LookupVar(tok1, tok1->strAt(1)); } } } } //--------------------------------------------------------------------------- void CheckOther::CheckVariableScope_LookupVar(const Token *tok1, const char varname[]) { const Token *tok = tok1; // Skip the variable declaration.. while (tok && !Token::Match(tok, ";")) tok = tok->next(); // Check if the variable is used in this indentlevel.. bool used = false, used1 = false; int indentlevel = 0; int parlevel = 0; bool for_or_while = false; while (indentlevel >= 0 && tok) { if (tok->str() == "{") { ++indentlevel; } else if (tok->str() == "}") { --indentlevel; if (indentlevel == 0) { if (for_or_while && used) return; used1 = used; used = false; } } else if (tok->str() == "(") { ++parlevel; } else if (tok->str() == ")") { --parlevel; } else if (tok->str() == varname) { if (indentlevel == 0 || used1) return; used = true; } else if (indentlevel == 0) { if ((tok->str() == "for") || (tok->str() == "while")) for_or_while = true; if (parlevel == 0 && (tok->str() == ";")) for_or_while = false; } tok = tok->next(); } // Warning if "used" is true std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok1) << " The scope of the variable '" << varname << "' can be limited"; _errorLogger->reportErr(errmsg.str()); } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Check for constant function parameters //--------------------------------------------------------------------------- void CheckOther::CheckConstantFunctionParameter() { for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "[,(] const std :: %type% %var% [,)]")) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok) << " " << tok->strAt(5) << " is passed by value, it could be passed by reference/pointer instead"; _errorLogger->reportErr(errmsg.str()); } else if (Token::Match(tok, "[,(] const %type% %var% [,)]")) { // Check if type is a struct or class. const std::string pattern(std::string("class|struct ") + tok->strAt(2)); if (Token::findmatch(_tokenizer->tokens(), pattern.c_str())) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok) << " " << tok->strAt(3) << " is passed by value, it could be passed by reference/pointer instead"; _errorLogger->reportErr(errmsg.str()); } } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Check that all struct members are used //--------------------------------------------------------------------------- void CheckOther::CheckStructMemberUsage() { const char *structname = 0; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->fileIndex() != 0) continue; if (tok->str() == "}") structname = 0; if (Token::Match(tok, "struct|union %type% {")) structname = tok->strAt(1); if (structname && Token::Match(tok, "[{;]")) { const char *varname = 0; if (Token::Match(tok->next(), "%type% %var% [;[]")) varname = tok->strAt(2); else if (Token::Match(tok->next(), "%type% %type% %var% [;[]")) varname = tok->strAt(2); 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; const std::string usagePattern(". " + std::string(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) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok->next()) << ": struct or union member '" << structname << "::" << varname << "' is never used"; _errorLogger->reportErr(errmsg.str()); } } } } //--------------------------------------------------------------------------- // Check usage of char variables.. //--------------------------------------------------------------------------- void CheckOther::CheckCharVariable() { for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { // Declaring the variable.. if (Token::Match(tok, "[{};(,] char %var% [;=,)]")) { // Set tok to point to the variable name tok = tok->tokAt(2); // 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; } std::string temp = "%var% [ " + tok->str() + " ]"; if ((tok2->str() != ".") && Token::Match(tok2->next(), temp.c_str())) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok2->next()) << ": Warning - using char variable as array index"; _errorLogger->reportErr(errmsg.str()); break; } std::string tempFirst = "%var% [&|] " + tok->str(); std::string tempSecond = tok->str() + " [&|]"; if (Token::Match(tok2, tempFirst.c_str()) || Token::Match(tok2, tempSecond.c_str())) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok2) << ": Warning - using char variable in bit operation"; _errorLogger->reportErr(errmsg.str()); break; } } } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Incomplete statement.. //--------------------------------------------------------------------------- void CheckOther::CheckIncompleteStatement() { int parlevel = 0; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->str() == "(") ++parlevel; else if (tok->str() == ")") --parlevel; if (parlevel != 0) continue; if ((tok->str() != "#") && Token::Match(tok->next(), "; %str%") && !Token::Match(tok->tokAt(3), ",")) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok->next()) << ": Redundant code: Found a statement that begins with string constant"; _errorLogger->reportErr(errmsg.str()); } if (!Token::Match(tok, "#") && Token::Match(tok->next(), "; %num%") && !Token::Match(tok->tokAt(3), ",")) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok->next()) << ": Redundant code: Found a statement that begins with numeric constant"; _errorLogger->reportErr(errmsg.str()); } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Unreachable code below a 'return' //--------------------------------------------------------------------------- void CheckOther::unreachableCode() { const Token *tok = Token::findmatch(_tokenizer->tokens(), "[;{}] return"); while (tok) { // Goto the 'return' token tok = tok->next(); // Locate the end of the 'return' statement while (tok && ! Token::Match(tok, ";")) tok = tok->next(); while (tok && Token::Match(tok->next(), ";")) tok = tok->next(); // If there is a statement below the return it is unreachable if (!Token::Match(tok, "; case|default|}|#") && !Token::Match(tok, "; %var% :")) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok->next()) << ": Unreachable code below a 'return'"; _errorLogger->reportErr(errmsg.str()); } // Find the next 'return' statement tok = Token::findmatch(tok, "[;{}] return"); } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Usage of function variables //--------------------------------------------------------------------------- static bool isOp(const Token *tok) { return bool(tok && (tok->str() == "&&" || tok->str() == "||" || tok->str() == "==" || tok->str() == "!=" || tok->str() == "<" || tok->str() == "<=" || tok->str() == ">" || tok->str() == ">=" || tok->str() == "<<" || Token::Match(tok, "[+-*/%&!~|^,[])?:]"))); } void CheckOther::functionVariableUsage() { // Parse all executing scopes.. const Token *tok1 = _tokenizer->tokens(); if (!tok1) return; while ((tok1 = Token::findmatch(tok1->next(), ") const| {")) != NULL) { // Varname, usage {1=declare, 2=read, 4=write} std::map varUsage; static const unsigned int USAGE_DECLARE = 1; static const unsigned int USAGE_READ = 2; static const unsigned int USAGE_WRITE = 4; int indentlevel = 0; for (const Token *tok = tok1; tok; tok = tok->next()) { if (tok->str() == "{") ++indentlevel; else if (tok->str() == "}") { --indentlevel; if (indentlevel <= 0) break; } else if (Token::Match(tok, "struct|union|class {") || Token::Match(tok, "struct|union|class %type% {")) { while (tok && tok->str() != "}") tok = tok->next(); if (tok) continue; break; } if (Token::Match(tok, "[;{}] bool|char|short|int|long|float|double %var% ;|=")) varUsage[ tok->strAt(2)] = USAGE_DECLARE; if (Token::Match(tok, "[;{}] bool|char|short|int|long|float|double * %var% ;|=")) varUsage[ tok->strAt(3)] = USAGE_DECLARE; if (Token::Match(tok, "delete|return %var%")) varUsage[ tok->strAt(1)] |= USAGE_READ; if (Token::Match(tok, "%var% =")) varUsage[ tok->str()] |= USAGE_WRITE; if (Token::Match(tok, "else %var% =")) varUsage[ tok->strAt(1)] |= USAGE_WRITE; if (Token::Match(tok, ">>|& %var%")) varUsage[ tok->strAt(1)] |= USAGE_WRITE; if ((Token::Match(tok, "[(=&!]") || isOp(tok)) && Token::Match(tok->next(), "%var%")) varUsage[ tok->strAt(1)] |= USAGE_READ; if (Token::Match(tok, "-=|+=|*=|/=|&=|^= %var%") || Token::Match(tok, "|= %var%")) varUsage[ tok->strAt(1)] |= USAGE_READ; if (Token::Match(tok, "%var%") && (tok->next()->str() == ")" || isOp(tok->next()))) varUsage[ tok->str()] |= USAGE_READ; if (Token::Match(tok, "[(,] %var% [,)]")) varUsage[ tok->strAt(1)] |= USAGE_WRITE; } // Check usage of all variables in the current scope.. for (std::map::const_iterator it = varUsage.begin(); it != varUsage.end(); ++it) { std::string varname = it->first; unsigned int usage = it->second; if (!std::isalpha(varname[0])) continue; if (!(usage & USAGE_DECLARE)) continue; if (usage == USAGE_DECLARE) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok1->next()) << ": Unused variable '" << varname << "'"; _errorLogger->reportErr(errmsg.str()); } else if (!(usage & USAGE_READ)) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok1->next()) << ": Variable '" << varname << "' is assigned a value that is never used"; _errorLogger->reportErr(errmsg.str()); } else if (!(usage & USAGE_WRITE)) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok1->next()) << ": Variable '" << varname << "' is not assigned a value"; _errorLogger->reportErr(errmsg.str()); } } } }