/* * c++check - c/c++ syntax checking * Copyright (C) 2007 Daniel Marjamäki * * 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 // free #include #include #ifdef __BORLANDC__ #include // <- memset #else #include #endif #ifndef _MSC_VER #define _strdup(str) strdup(str) #endif //--------------------------------------------------------------------------- static bool isclass( const std::string &typestr ) { if ( typestr == "char" || typestr == "short" || typestr == "int" || typestr == "long" || typestr == "float" || typestr == "double" ) return false; std::ostringstream pattern; pattern << "struct " << typestr; if ( findmatch( tokens, pattern.str().c_str() ) ) return false; return true; } //--------------------------------------------------------------------------- enum AllocType { No, Malloc, gMalloc, New, NewA }; // Extra allocation.. class AllocFunc { public: const char *funcname; AllocType alloctype; AllocFunc(const char f[], AllocType a) { funcname = f; alloctype = a; } }; static std::list listallocfunc; static AllocType GetAllocationType( const TOKEN *tok2 ) { // What we may have... // * var = (char *)malloc(10); // * var = new char[10]; // * var = strdup("hello"); if ( tok2 && tok2->str[0] == '(' ) { while ( tok2 && tok2->str[0] != ')' ) tok2 = tok2->next; tok2 = tok2 ? tok2->next : NULL; } if ( ! tok2 ) return No; // Does tok2 point on "malloc", "strdup" or "kmalloc".. const char *mallocfunc[] = {"malloc", "calloc", "realloc", "strdup", "kmalloc", "kzalloc", 0}; for ( unsigned int i = 0; mallocfunc[i]; i++ ) { if ( strcmp(mallocfunc[i], tok2->str) == 0 ) return Malloc; } // Does tok2 point on "malloc", "strdup" or "kmalloc".. const char *gmallocfunc[] = {"g_new", "g_new0", "g_renew", "g_try_new", "g_try_new0", "g_try_renew", "g_malloc", "g_malloc0", "g_realloc", "g_try_malloc", "g_try_malloc0", "g_try_realloc", "g_strdup", "g_strndup", 0}; for ( unsigned int i = 0; gmallocfunc[i]; i++ ) { if ( strcmp(gmallocfunc[i], tok2->str) == 0 ) return gMalloc; } if ( Match( tok2, "new %type% [;(]" ) ) return New; if ( Match( tok2, "new %type% [" ) ) return NewA; // Userdefined allocation function.. std::list::const_iterator it = listallocfunc.begin(); while ( it != listallocfunc.end() ) { if ( strcmp(tok2->str, it->funcname) == 0 ) return it->alloctype; ++it; } return No; } static AllocType GetDeallocationType( const TOKEN *tok, const char *varnames[] ) { // Redundant condition.. if ( Match(tok, "if ( %var1% )", varnames) ) { tok = gettok( tok, 4 ); if ( Match(tok,"{") ) tok = tok->next; } if ( Match(tok, "delete %var1% ;", varnames) ) return New; if ( Match(tok, "delete [ ] %var1% ;", varnames) ) return NewA; if ( Match(tok, "free ( %var1% ) ;", varnames) || Match(tok, "kfree ( %var1% ) ;", varnames) ) { return Malloc; } if ( Match(tok, "g_free ( %var1% ) ;", varnames) ) return gMalloc; return No; } //--------------------------------------------------------------------------- static void MismatchError( const TOKEN *Tok1, const char varname[] ) { std::ostringstream errmsg; errmsg << FileLine(Tok1) << ": Mismatching allocation and deallocation: " << varname; ReportErr( errmsg.str() ); } //--------------------------------------------------------------------------- static void MemoryLeak( const TOKEN *tok, const char varname[] ) { std::ostringstream errmsg; errmsg << FileLine(tok) << ": Memory leak: " << varname; ReportErr( errmsg.str() ); } //--------------------------------------------------------------------------- static void instoken(TOKEN *tok, const char str[]) { TOKEN *newtok = new TOKEN; newtok->setstr(str); newtok->next = tok->next; tok->next = newtok; } //--------------------------------------------------------------------------- static bool notvar(const TOKEN *tok, const char *varnames[]) { return bool( Match(tok, "! %var1% [;)&|]", varnames) || Match(tok, "unlikely ( ! %var1% )", varnames) || Match(tok, "unlikely ( %var1% == NULL )", varnames) || Match(tok, "%var1% == NULL", varnames) || Match(tok, "NULL == %var1% [;)&|]", varnames) || (!Match(tok,".") && Match(tok->next, "%var1% == 0", varnames)) ); } extern bool ShowAll; /** * Extract a new tokens list that is easier to parse than the "tokens" * tok - start parse token * varname - name of variable */ static TOKEN *getcode(const TOKEN *tok, const char varname[]) { const char *varnames[2]; varnames[0] = varname; varnames[1] = 0; TOKEN *rethead = 0, *rettail = 0; #define addtoken(_str) \ { \ TOKEN *newtok = new TOKEN; \ newtok->setstr(_str); \ newtok->linenr = tok->linenr; \ newtok->FileIndex = tok->FileIndex; \ newtok->next = 0; \ if (rettail) \ rettail->next = newtok; \ else \ rethead = newtok; \ rettail=newtok; \ } AllocType alloctype = No; AllocType dealloctype = No; bool isloop = false; int indentlevel = 0; int parlevel = 0; for ( ; tok; tok = tok->next ) { if ( tok->str[0] == '{' ) { addtoken( "{" ); indentlevel++; } else if ( tok->str[0] == '}' ) { addtoken( "}" ); if ( indentlevel <= 0 ) break; indentlevel--; } if ( tok->str[0] == '(' ) parlevel++; else if ( tok->str[0] == ')' ) parlevel--; isloop &= ( parlevel > 0 ); if ( parlevel == 0 && tok->str[0]==';') addtoken(";"); if (Match(tok, "[(;{}] %var1% =", varnames)) { AllocType alloc = GetAllocationType(gettok(tok,3)); // If "--all" hasn't been given, don't check classes.. if ( alloc == New && ! ShowAll ) { if ( Match(gettok(tok,3), "new %type% [(;]") ) { if ( isclass( getstr(tok, 4) ) ) alloc = No; } } if ( alloc != No ) { addtoken("alloc"); if (alloctype!=No && alloctype!=alloc) MismatchError(tok, varname); if (dealloctype!=No && dealloctype!=alloc) MismatchError(tok, varname); alloctype = alloc; } } AllocType dealloc = GetDeallocationType(tok, varnames); if ( dealloc != No ) { addtoken("dealloc"); if (alloctype!=No && alloctype!=dealloc) MismatchError(tok, varname); if (dealloctype!=No && dealloctype!=dealloc) MismatchError(tok, varname); dealloctype = dealloc; } // if else switch if ( Match(tok, "if ( %var1% )", varnames) || Match(tok, "if ( %var1% != NULL )", varnames) ) { addtoken("if(var)"); tok = gettok(tok, 3); // Make sure the "use" will not be added } else if ( Match(tok, "if (") && notvar(gettok(tok,2), varnames) ) { addtoken("if(!var)"); } else if ( Match(tok, "if") || Match(tok, "else") || Match(tok, "switch") ) { addtoken(tok->str); } if ( Match(tok, "case") ) { addtoken("case"); addtoken(";"); } if ( Match(tok, "default") ) { addtoken("case"); addtoken(";"); } // Loops.. if (Match(tok, "for") || Match(tok, "while") ) { addtoken("loop"); isloop = true; } if ( Match(tok, "do") ) { addtoken("do"); } if ( isloop && notvar(tok,varnames) ) addtoken("!var"); // continue / break.. if ( Match(tok, "continue") ) addtoken("continue"); if ( Match(tok, "break") ) addtoken("break"); // goto.. if ( Match(tok, "goto") ) addtoken( "goto" ); // Return.. if ( Match(tok, "return") ) { addtoken("return"); if ( Match(tok, "return %var1%", varnames) || Match(tok, "return & %var1%", varnames) ) addtoken("use"); } // Assignment.. if ( Match(tok,"[)=] %var1% [;)]", varnames) ) addtoken("use"); // Function parameter.. if ( Match(tok, "[(,)] %var1% [,)]", varnames) ) addtoken("use"); // Linux lists.. if ( Match( tok, "[=(,] & %var1% [.[]", varnames ) ) { // todo: better checking addtoken("use"); } } return rethead; } static void erase(TOKEN *begin, const TOKEN *end) { if ( ! begin ) return; while ( begin->next && begin->next != end ) { TOKEN *next = begin->next; begin->next = begin->next->next; delete next; } } // Simpler but less powerful than "CheckMemoryLeak_CheckScope_All" static void CheckMemoryLeak_CheckScope( const TOKEN *Tok1, const char varname[] ) { TOKEN *tok = getcode( Tok1, varname ); // If the variable is not allocated at all => no memory leak if (findmatch(tok, "alloc") == 0) { deleteTokens(tok); return; } // Remove "do"... // do { x } while (y); // => // { x } while(y) { x }" for ( TOKEN *tok2 = tok; tok2; tok2 = tok2->next ) { if ( ! Match(tok2->next, "do") ) continue; // Remove the next token "do" erase( tok2, gettok(tok2, 2) ); tok2 = tok2->next; // Find the end of the "do" block.. TOKEN *tok2_; int indentlevel = 0; for ( tok2_ = tok2; tok2_ && indentlevel>=0; tok2_ = tok2_->next ) { if ( Match(tok2_, "{") ) ++indentlevel; else if ( Match(tok2_, "}") ) --indentlevel; else if ( indentlevel == 0 && Match(tok2_->next, ";") ) break; } // End not found? if ( ! tok2_ ) continue; // Copy code.. indentlevel = 0; do { if ( Match( tok2, "{" ) ) ++indentlevel; else if ( Match(tok2, "}") ) --indentlevel; // Copy token.. instoken( tok2_, tok2->str ); // Next token.. tok2 = tok2->next; tok2_ = tok2_->next; } while ( tok2 && indentlevel > 0 ); } // reduce the code.. bool done = false; while ( ! done ) { done = true; for (TOKEN *tok2 = tok; tok2; tok2 = tok2 ? tok2->next : NULL ) { // Delete extra ";" while (Match(tok2,"[;{}] ;")) { erase(tok2, gettok(tok2,2)); done = false; } // Replace "{ }" with ";" if ( Match(tok2->next, "{ }") ) { tok2->next->setstr(";"); erase(tok2->next, gettok(tok2,3)); done = false; } // Delete braces around a single instruction.. if ( Match(tok2->next, "{ %var% ; }") ) { erase( tok2, gettok(tok2,2) ); erase( tok2->next->next, gettok(tok2,4) ); done = false; } if ( Match(tok2->next, "{ return use ; }") ) { erase( tok2, gettok(tok2,2) ); erase( tok2->next->next->next, gettok(tok2,5) ); done = false; } // Delete empty if that is not followed by an else if ( Match(tok2,"[;{}] if ;") || Match(tok2,"[;{}] if(var) ;") || Match(tok2,"[;{}] if(!var) ;") ) { if ( ! Match(gettok(tok2,3), "else") ) { erase(tok2, gettok(tok2, 3)); done = false; continue; } } // Delete if block: "alloc; if return use ;" if (Match(tok2,"alloc ; if return use ;") && !Match(gettok(tok2,6),"else")) { erase(tok2, gettok(tok2,5)); done = false; } // "[;{}] if alloc ; else return ;" => "[;{}] alloc ;" if (Match(tok2,"[;{}] if alloc ; else return ;")) { erase(tok2, gettok(tok2,2)); // Remove "if" erase(tok2->next, gettok(tok2,5)); // Remove "; else return" done = false; } // Replace "dealloc use ;" with "dealloc ;" if ( Match(tok2, "dealloc use ;") ) { erase(tok2, gettok(tok2,2)); done = false; } // Reducing if.. if (Match(tok2,"if dealloc ; else") || Match(tok2,"if use ; else")) { erase(tok2, gettok(tok2, 2)); done = false; } if (Match(tok2,"[;{}] if { dealloc ; return ; }") && !Match(gettok(tok2,8),"else")) { erase(tok2,gettok(tok2,8)); done = false; } // Replace "loop ;" with ";" if ( Match(tok2->next, "loop ;") ) { erase(tok2, gettok(tok2,2)); done = false; } // Replace "loop !var ;" with ";" if ( Match(tok2->next, "loop !var ;") ) { erase(tok2, gettok(tok2,4)); done = false; } // Replace "loop !var alloc ;" with " alloc ;" if ( Match(tok2->next, "loop !var alloc ;") ) { erase(tok2, gettok(tok2,3)); done = false; } // Delete if block in "alloc ; if(!var) return ;" if ( Match(tok2, "alloc ; if(!var) return ;") ) { erase(tok2, gettok(tok2,4)); done = false; } // Delete second use in "use ; use ;" while (Match(tok2, "use ; use ;")) { erase(tok2, gettok(tok2,3)); done = false; } // Delete second case in "case ; case ;" while (Match(tok2, "case ; case ;")) { erase(tok2, gettok(tok2,3)); done = false; } // Replace switch with if (if not complicated) if (Match(tok2, "switch {")) { // Right now, I just handle if there are a few case and perhaps a default. bool valid = false; bool incase = false; for ( const TOKEN * _tok = gettok(tok2,2); _tok; _tok = _tok->next ) { if ( _tok->str[0] == '{' ) break; else if ( _tok->str[0] == '}' ) { valid = true; break; } else if (strncmp(_tok->str,"if",2)==0) break; else if (strcmp(_tok->str,"switch")==0) break; else if (strcmp(_tok->str,"loop")==0) break; else if (incase && Match(_tok,"case")) break; incase |= Match(_tok,"case"); incase &= !Match(_tok,"break"); } if ( !incase && valid ) { done = false; tok2->setstr(";"); erase( tok2, gettok(tok2, 2) ); tok2 = tok2->next; bool first = true; while (Match(tok2,"case") || Match(tok2,"default")) { bool def = Match(tok2, "default"); tok2->setstr(first ? "if" : "}"); if ( first ) { first = false; instoken( tok2, "{" ); } else { // Insert "else [if] { instoken( tok2, "{" ); if ( ! def ) instoken( tok2, "if" ); instoken( tok2, "else" ); } while ( tok2 && tok2->str[0] != '}' && ! Match(tok2,"break ;") ) tok2 = tok2->next; if (Match(tok2,"break ;")) { tok2->setstr(";"); tok2 = tok2->next->next; } } } } } } if ( findmatch(tok, "loop alloc ;") ) { MemoryLeak(findmatch(tok, "loop alloc ;"), varname); } else if ( findmatch(tok, "alloc ; if continue ;") ) { MemoryLeak(gettok(findmatch(tok, "alloc ; if continue ;"), 3), varname); } else if ( findmatch(tok, "alloc ; if return ;") ) { MemoryLeak(gettok(findmatch(tok, "alloc ; if return ;"), 3), varname); } else if ( findmatch(tok, "alloc ; return ;") ) { MemoryLeak(gettok(findmatch(tok,"alloc ; return ;"),2), varname); } else if ( findmatch(tok, "alloc ; alloc") ) { MemoryLeak(gettok(findmatch(tok,"alloc ; alloc"),2), varname); } else if ( ! findmatch(tok,"dealloc") && ! findmatch(tok,"use") && ! findmatch(tok,"return use ;") ) { const TOKEN *last = tok; while (last->next) last = last->next; MemoryLeak(last, varname); } deleteTokens(tok); } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Checks for memory leaks inside function.. //--------------------------------------------------------------------------- static void CheckMemoryLeak_InFunction() { bool infunc = false; int indentlevel = 0; for (const TOKEN *tok = tokens; tok; tok = tok->next) { if (tok->str[0]=='{') indentlevel++; else if (tok->str[0]=='}') indentlevel--; // In function.. if ( indentlevel == 0 ) { if ( Match(tok, ") {") ) infunc = true; if ( Match(tok, "[;}]") ) infunc = false; } // Declare a local variable => Check if (indentlevel>0 && infunc) { if ( Match(tok, "[{};] %type% * %var% [;=]") ) CheckMemoryLeak_CheckScope( tok->next, getstr(tok, 3) ); else if ( Match(tok, "[{};] %type% %type% * %var% [;=]") ) CheckMemoryLeak_CheckScope( tok->next, getstr(tok, 4) ); } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Checks for memory leaks in classes.. //--------------------------------------------------------------------------- static void CheckMemoryLeak_ClassMembers_ParseClass( const TOKEN *tok1, std::vector &classname ); static void CheckMemoryLeak_ClassMembers_Variable( const std::vector &classname, const char varname[] ); static void CheckMemoryLeak_ClassMembers() { int indentlevel = 0; for ( const TOKEN *tok = tokens; tok; tok = tok->next ) { if ( tok->str[0] == '{' ) indentlevel++; else if ( tok->str[0] == '}' ) indentlevel--; else if ( indentlevel == 0 && Match(tok, "class %var% [{:]") ) { std::vector classname; classname.push_back( getstr(tok, 1) ); CheckMemoryLeak_ClassMembers_ParseClass( tok, classname ); } } } static void CheckMemoryLeak_ClassMembers_ParseClass( const TOKEN *tok1, std::vector &classname ) { // Go into class. while ( tok1 && tok1->str[0] != '{' ) tok1 = tok1->next; if ( tok1 ) tok1 = tok1->next; int indentlevel = 0; for ( const TOKEN *tok = tok1; tok; tok = tok->next ) { if ( tok->str[0] == '{' ) indentlevel++; else if ( tok->str[0] == '}' ) { indentlevel--; if ( indentlevel < 0 ) return; } // Only parse this particular class.. not subclasses if ( indentlevel > 0 ) continue; // Declaring subclass.. recursive checking if ( Match(tok, "class %var% [{:]") ) { classname.push_back( getstr(tok, 1) ); CheckMemoryLeak_ClassMembers_ParseClass( tok, classname ); classname.pop_back(); } // Declaring member variable.. check allocations and deallocations if ( Match(tok->next, "%type% * %var% ;") ) { if ( IsName(tok->str) || strchr(";}", tok->str[0]) ) { if (ShowAll || !isclass(getstr(tok,1))) CheckMemoryLeak_ClassMembers_Variable( classname, getstr(tok, 3) ); } } } } static void CheckMemoryLeak_ClassMembers_Variable( const std::vector &classname, const char varname[] ) { // Function pattern.. Check if member function std::ostringstream fpattern; for ( unsigned int i = 0; i < classname.size(); i++ ) { fpattern << classname[i] << " :: "; } fpattern << "%var% ("; // Destructor pattern.. Check if class destructor.. std::ostringstream destructor; for ( unsigned int i = 0; i < classname.size(); i++ ) { destructor << classname[i] << " :: "; } destructor << " ~" << classname.back() << " ("; // Pattern used in member function. "Var = ..." std::ostringstream varname_eq; varname_eq << varname << " ="; // Full variable name.. std::ostringstream FullVariableName; for ( unsigned int i = 0; i < classname.size(); i++ ) FullVariableName << classname[i] << "::"; FullVariableName << varname; // Check if member variable has been allocated and deallocated.. AllocType Alloc = No; AllocType Dealloc = No; // Loop through all tokens. Inspect member functions bool memberfunction = false; int indentlevel = 0; for ( const TOKEN *tok = tokens; tok; tok = tok->next ) { if ( tok->str[0] == '{' ) indentlevel++; else if ( tok->str[0] == '}' ) indentlevel--; // Set the 'memberfunction' variable.. if ( indentlevel == 0 ) { if ( strchr(";}", tok->str[0]) ) memberfunction = false; else if ( Match( tok, fpattern.str().c_str() ) || Match( tok, destructor.str().c_str() ) ) memberfunction = true; } // Parse member function.. if ( indentlevel > 0 && memberfunction ) { // Allocate.. if ( Match( tok, varname_eq.str().c_str() ) ) { AllocType alloc = GetAllocationType( gettok( tok, 2 ) ); if ( alloc != No ) { if ( Dealloc != No && Dealloc != alloc ) MismatchError( tok, FullVariableName.str().c_str() ); if ( Alloc != No && Alloc != alloc ) MismatchError( tok, FullVariableName.str().c_str() ); Alloc = alloc; } } // Deallocate.. const char *varnames[2] = { "var", 0 }; varnames[0] = varname; AllocType dealloc = GetDeallocationType( tok, varnames ); if ( dealloc != No ) { if ( Dealloc != No && Dealloc != dealloc ) MismatchError( tok, FullVariableName.str().c_str() ); if ( Alloc != No && Alloc != dealloc ) MismatchError( tok, FullVariableName.str().c_str() ); Dealloc = dealloc; } } } if ( Alloc != No && Dealloc == No ) { MemoryLeak( tokens, FullVariableName.str().c_str() ); } } //--------------------------------------------------------------------------- // Checks for memory leaks.. //--------------------------------------------------------------------------- void CheckMemoryLeak() { listallocfunc.clear(); // Check for memory leaks inside functions.. CheckMemoryLeak_InFunction(); // Check that all class members are deallocated.. CheckMemoryLeak_ClassMembers(); } //---------------------------------------------------------------------------