/* * cppcheck - c/c++ syntax checking * Copyright (C) 2007-2008 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; std::ostringstream ostr; ostr << _tokenizer->fileLine(tok) << ": C-style pointer casting"; _errorLogger->reportErr(ostr.str()); } } //--------------------------------------------------------------------------- // 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) { std::ostringstream ostr; ostr << _tokenizer->fileLine(tok) << ": Redundant condition. It is safe to deallocate a NULL pointer"; _errorLogger->reportErr(ostr.str()); } } // 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() ) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok) << ": Redundant condition found. The remove function in the STL will not do anything if element doesn't exist"; _errorLogger->reportErr(errmsg.str()); } 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() { 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))) { std::ostringstream ostr; ostr << _tokenizer->fileLine(tok2) << ": Invalid radix in call to strtol or strtoul. Must be 0 or 2-36"; _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 _indentlevel = 0; for (tok = tok2; tok; tok = tok->next()) { if ( tok->str() == "{" ) { _indentlevel++; } if ( tok->str() == "}" ) { _indentlevel--; if ( _indentlevel <= 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 %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 char *varnames[2]; varnames[0] = varname; varnames[1] = 0; bool used = false; for ( const TOKEN *tok2 = _tokenizer->tokens(); tok2; tok2 = tok2->next() ) { if ( tok->fileIndex() != 0 ) continue; if (TOKEN::Match(tok2, ". %var%", varnames)) { if ( strcmp("=", tok2->strAt(2)) == 0 ) continue; used = true; break; } } if ( ! used ) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok) << ": struct member '" << structname << "::" << varname << "' is never read"; _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% [;=,)]") ) { const char *varname[2] = {0}; varname[0] = tok->strAt( 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; } if ((tok2->str() != ".") && TOKEN::Match(tok2->next(), "%var% [ %var1% ]", varname)) { std::ostringstream errmsg; errmsg << _tokenizer->fileLine(tok2->next()) << ": Warning - using char variable as array index"; _errorLogger->reportErr(errmsg.str()); break; } if ( TOKEN::Match(tok2, "%var% [&|] %var1%", varname) || TOKEN::Match(tok2, "%var1% [&|]", varname) ) { 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 = TOKEN::findmatch( _tokenizer->tokens(), ") const| {" ); while ( tok1 ) { // 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; } 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%")) 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()); } } // Goto next executing scope.. tok1 = TOKEN::findmatch( tok1->next(), ") const| {" ); } }