1515 lines
58 KiB
C++
1515 lines
58 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2013 Daniel Marjamäki and Cppcheck team.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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//---------------------------------------------------------------------------
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#include "checkuninitvar.h"
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#include "mathlib.h"
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#include "executionpath.h"
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#include "checknullpointer.h" // CheckNullPointer::parseFunctionCall
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#include "symboldatabase.h"
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#include <algorithm>
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#include <map>
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//---------------------------------------------------------------------------
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// Register this check class (by creating a static instance of it)
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namespace {
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CheckUninitVar instance;
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}
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//---------------------------------------------------------------------------
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// Skip [ .. ]
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static const Token * skipBrackets(const Token *tok)
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{
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while (tok && tok->str() == "[")
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tok = tok->link()->next();
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return tok;
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}
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/// @addtogroup Checks
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/// @{
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/**
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* @brief %Check that uninitialized variables aren't used (using ExecutionPath)
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* */
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class UninitVar : public ExecutionPath {
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public:
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/** Startup constructor */
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explicit UninitVar(Check *c, const SymbolDatabase* db, bool isc)
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: ExecutionPath(c, 0), symbolDatabase(db), isC(isc), var(0), alloc(false), strncpy_(false), memset_nonzero(false) {
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}
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private:
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/** Create a copy of this check */
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ExecutionPath *copy() {
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return new UninitVar(*this);
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}
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/** no implementation => compiler error if used */
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void operator=(const UninitVar &);
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/** internal constructor for creating extra checks */
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UninitVar(Check *c, const Variable* v, const SymbolDatabase* db, bool isc)
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: ExecutionPath(c, v->varId()), symbolDatabase(db), isC(isc), var(v), alloc(false), strncpy_(false), memset_nonzero(false) {
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}
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/** is other execution path equal? */
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bool is_equal(const ExecutionPath *e) const {
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const UninitVar *c = static_cast<const UninitVar *>(e);
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return (var == c->var && alloc == c->alloc && strncpy_ == c->strncpy_ && memset_nonzero == c->memset_nonzero);
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}
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/** pointer to symbol database */
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const SymbolDatabase* symbolDatabase;
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const bool isC;
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/** variable for this check */
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const Variable* var;
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/** is this variable allocated? */
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bool alloc;
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/** is this variable initialized with strncpy (not always zero-terminated) */
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bool strncpy_;
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/** is this variable initialized but not zero-terminated (memset) */
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bool memset_nonzero;
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/** allocating pointer. For example : p = malloc(10); */
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static void alloc_pointer(std::list<ExecutionPath *> &checks, unsigned int varid) {
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// loop through the checks and perform a allocation if the
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// variable id matches
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std::list<ExecutionPath *>::const_iterator it;
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for (it = checks.begin(); it != checks.end(); ++it) {
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid) {
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if (c->var->isPointer() && !c->var->isArray())
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c->alloc = true;
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else
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bailOutVar(checks, varid);
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break;
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}
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}
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}
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/** Initializing a pointer value. For example: *p = 0; */
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static void init_pointer(std::list<ExecutionPath *> &checks, const Token *tok) {
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const unsigned int varid(tok->varId());
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if (!varid)
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return;
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// loop through the checks and perform a initialization if the
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// variable id matches
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std::list<ExecutionPath *>::iterator it = checks.begin();
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while (it != checks.end()) {
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid) {
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if (c->alloc || c->var->isArray()) {
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delete c;
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checks.erase(it++);
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continue;
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} else {
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use_pointer(checks, tok);
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}
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}
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++it;
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}
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}
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/** Deallocate a pointer. For example: free(p); */
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static void dealloc_pointer(std::list<ExecutionPath *> &checks, const Token *tok) {
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const unsigned int varid(tok->varId());
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if (!varid)
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return;
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// loop through the checks and perform a deallocation if the
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// variable id matches
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std::list<ExecutionPath *>::const_iterator it;
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for (it = checks.begin(); it != checks.end(); ++it) {
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid) {
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// unallocated pointer variable => error
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if (c->var->isPointer() && !c->var->isArray() && !c->alloc) {
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CheckUninitVar *checkUninitVar = dynamic_cast<CheckUninitVar *>(c->owner);
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if (checkUninitVar) {
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checkUninitVar->uninitvarError(tok, c->var->name());
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break;
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}
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}
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c->alloc = false;
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}
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}
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}
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/**
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* Pointer assignment: p = x;
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* if p is a pointer and x is an array/pointer then bail out
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* \param checks all available checks
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* \param tok1 the "p" token
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* \param tok2 the "x" token
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*/
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static void pointer_assignment(std::list<ExecutionPath *> &checks, const Token *tok1, const Token *tok2) {
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// Variable id for "left hand side" variable
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const unsigned int varid1(tok1->varId());
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if (varid1 == 0)
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return;
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// Variable id for "right hand side" variable
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const unsigned int varid2(tok2->varId());
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if (varid2 == 0)
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return;
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std::list<ExecutionPath *>::const_iterator it;
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// bail out if first variable is a pointer
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for (it = checks.begin(); it != checks.end(); ++it) {
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid1 && c->var->isPointer() && !c->var->isArray()) {
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bailOutVar(checks, varid1);
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break;
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}
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}
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// bail out if second variable is a array/pointer
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for (it = checks.begin(); it != checks.end(); ++it) {
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid2 && (c->var->isPointer() || c->var->isArray())) {
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bailOutVar(checks, varid2);
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break;
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}
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}
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}
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/** Initialize an array with strncpy. */
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static void init_strncpy(std::list<ExecutionPath *> &checks, const Token *tok) {
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const unsigned int varid(tok->varId());
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if (!varid)
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return;
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std::list<ExecutionPath *>::const_iterator it;
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for (it = checks.begin(); it != checks.end(); ++it) {
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid) {
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c->strncpy_ = true;
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}
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}
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}
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/** Initialize an array with memset (not zero). */
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static void init_memset_nonzero(std::list<ExecutionPath *> &checks, const Token *tok) {
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const unsigned int varid(tok->varId());
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if (!varid)
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return;
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std::list<ExecutionPath *>::const_iterator it;
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for (it = checks.begin(); it != checks.end(); ++it) {
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid) {
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c->memset_nonzero = true;
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}
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}
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}
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/**
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* use - called from the use* functions below.
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* @param checks all available checks
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* @param tok variable token
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* @param mode specific behaviour
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* @return if error is found, true is returned
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*/
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static bool use(std::list<ExecutionPath *> &checks, const Token *tok, const int mode) {
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const unsigned int varid(tok->varId());
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if (varid == 0)
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return false;
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std::list<ExecutionPath *>::const_iterator it;
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for (it = checks.begin(); it != checks.end(); ++it) {
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid) {
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// mode 0 : the variable is used "directly"
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// example: .. = var;
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// it is ok to read the address of an uninitialized array.
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// it is ok to read the address of an allocated pointer
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if (mode == 0 && (c->var->isArray() || (c->var->isPointer() && c->alloc)))
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continue;
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// mode 2 : reading array data with mem.. function. It's ok if the
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// array is not null-terminated
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if (mode == 2 && c->strncpy_)
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continue;
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// mode 3 : bad usage of pointer. if it's not a pointer then the usage is ok.
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// example: ptr->foo();
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if (mode == 3 && (!c->var->isPointer() || c->var->isArray()))
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continue;
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// mode 4 : using dead pointer is invalid.
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if (mode == 4 && (!c->var->isPointer() || c->var->isArray() || c->alloc))
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continue;
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// mode 5 : reading uninitialized array or pointer is invalid.
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if (mode == 5 && (!c->var->isArray() && !c->var->isPointer()))
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continue;
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CheckUninitVar *checkUninitVar = dynamic_cast<CheckUninitVar *>(c->owner);
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if (checkUninitVar) {
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if (c->strncpy_ || c->memset_nonzero)
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checkUninitVar->uninitstringError(tok, c->var->name(), c->strncpy_);
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else if (c->var->isPointer() && !c->var->isArray() && c->alloc)
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checkUninitVar->uninitdataError(tok, c->var->name());
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else
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checkUninitVar->uninitvarError(tok, c->var->name());
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return true;
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}
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}
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}
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// No error found
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return false;
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}
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/**
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* Reading variable. Use this function in situations when it is
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* invalid to read the data of the variable but not the address.
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* @param checks all available checks
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* @param tok variable token
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* @return if error is found, true is returned
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*/
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static bool use(std::list<ExecutionPath *> &checks, const Token *tok) {
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return use(checks, tok, 0);
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}
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/**
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* Reading array elements. If the variable is not an array then the usage is ok.
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* @param checks all available checks
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* @param tok variable token
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*/
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static void use_array(std::list<ExecutionPath *> &checks, const Token *tok) {
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use(checks, tok, 1);
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}
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/**
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* Reading array elements with a "mem.." function. It's ok if the array is not null-terminated.
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* @param checks all available checks
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* @param tok variable token
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*/
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static void use_array_mem(std::list<ExecutionPath *> &checks, const Token *tok) {
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use(checks, tok, 2);
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}
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/**
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* Bad pointer usage. If the variable is not a pointer then the usage is ok.
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* @param checks all available checks
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* @param tok variable token
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* @return if error is found, true is returned
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*/
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static bool use_pointer(std::list<ExecutionPath *> &checks, const Token *tok) {
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return use(checks, tok, 3);
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}
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/**
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* Using variable.. if it's a dead pointer the usage is invalid.
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* @param checks all available checks
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* @param tok variable token
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* @return if error is found, true is returned
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*/
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static bool use_dead_pointer(std::list<ExecutionPath *> &checks, const Token *tok) {
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return use(checks, tok, 4);
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}
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/**
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* Using variable.. reading from uninitialized array or pointer data is invalid.
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* Example: = x[0];
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* @param checks all available checks
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* @param tok variable token
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* @return if error is found, true is returned
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*/
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static bool use_array_or_pointer_data(std::list<ExecutionPath *> &checks, const Token *tok) {
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return use(checks, tok, 5);
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}
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/**
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* Parse right hand side expression in statement
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* @param tok2 start token of rhs
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* @param checks the execution paths
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*/
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void parserhs(const Token *tok2, std::list<ExecutionPath *> &checks) const {
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// check variable usages in rhs/index
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while (NULL != (tok2 = tok2->next())) {
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if (Token::Match(tok2, "[;)=]"))
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break;
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if (Token::Match(tok2, "%var% ("))
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break;
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if (tok2->varId() &&
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!Token::Match(tok2->previous(), "&|::") &&
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!Token::simpleMatch(tok2->tokAt(-2), "& (") &&
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!Token::simpleMatch(tok2->next(), "=")) {
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// Multiple assignments..
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if (Token::Match(tok2->next(), ".|[")) {
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const Token * tok3 = tok2;
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while (tok3) {
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if (Token::Match(tok3->next(), ". %var%"))
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tok3 = tok3->tokAt(2);
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else if (tok3->strAt(1) == "[")
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tok3 = tok3->next()->link();
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else
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break;
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}
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if (tok3 && tok3->strAt(1) == "=")
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continue;
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}
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bool foundError;
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if (tok2->previous()->str() == "*" || tok2->next()->str() == "[")
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foundError = use_array_or_pointer_data(checks, tok2);
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else
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foundError = use(checks, tok2);
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// prevent duplicate error messages
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if (foundError) {
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bailOutVar(checks, tok2->varId());
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}
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}
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}
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}
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/** parse tokens. @sa ExecutionPath::parse */
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const Token *parse(const Token &tok, std::list<ExecutionPath *> &checks) const {
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// Variable declaration..
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if (tok.varId() && Token::Match(&tok, "%var% [[;]")) {
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const Variable* var2 = symbolDatabase->getVariableFromVarId(tok.varId());
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if (var2 && var2->nameToken() == &tok && !var2->isStatic() && !var2->isExtern() && !var2->isConst()) {
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if (tok.linkAt(1)) { // array
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const Token* endtok = tok.next();
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while (endtok->link())
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endtok = endtok->link()->next();
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if (endtok->str() != ";")
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return &tok;
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}
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const Scope* parent = var2->scope()->nestedIn;
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while (parent) {
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for (std::list<Variable>::const_iterator j = parent->varlist.begin(); j != parent->varlist.end(); ++j) {
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if (j->name() == var2->name()) {
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ExecutionPath::bailOutVar(checks, j->varId()); // If there is a variable with the same name in other scopes, this might cause false positives, if there are unexpanded macros
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break;
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}
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}
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parent = parent->nestedIn;
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}
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if (var2->isPointer())
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checks.push_back(new UninitVar(owner, var2, symbolDatabase, isC));
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else if (var2->typeEndToken()->str() != ">") {
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bool stdtype = false; // TODO: change to isC to handle unknown types better
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for (const Token* tok2 = var2->typeStartToken(); tok2 != var2->nameToken(); tok2 = tok2->next()) {
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if (tok2->isStandardType()) {
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stdtype = true;
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break;
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}
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}
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if (stdtype && (!var2->isArray() || var2->nameToken()->linkAt(1)->strAt(1) == ";"))
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checks.push_back(new UninitVar(owner, var2, symbolDatabase, isC));
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}
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return &tok;
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}
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}
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if (tok.str() == "return") {
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// is there assignment or ternary operator in the return statement?
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bool assignment = false;
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for (const Token *tok2 = tok.next(); tok2 && tok2->str() != ";"; tok2 = tok2->next()) {
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if (tok2->str() == "=" || (!isC && tok2->str() == ">>") || Token::Match(tok2, "(|, &")) {
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assignment = true;
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break;
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}
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if (Token::Match(tok2, "[(,] &| %var% [,)]")) {
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tok2 = tok2->next();
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if (!tok2->isName())
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tok2 = tok2->next();
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ExecutionPath::bailOutVar(checks, tok2->varId());
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}
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}
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if (!assignment) {
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for (const Token *tok2 = tok.next(); tok2 && tok2->str() != ";"; tok2 = tok2->next()) {
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if (tok2->isName() && tok2->strAt(1) == "(")
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tok2 = tok2->next()->link();
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else if (tok2->varId())
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use(checks, tok2);
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}
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}
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}
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if (tok.varId()) {
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// array variable passed as function parameter..
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if (Token::Match(tok.previous(), "[(,] %var% [+-,)]")) {
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// skip ')'..
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const Token *tok2 = tok.next();
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while (tok2 && tok2->str() == ")")
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tok2 = tok2->next();
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// variable is assigned like: "( %var% ) .. ="
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if (Token::Match(tok.previous(), "( %var% )") && tok2 && tok2->str() == "=")
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ExecutionPath::bailOutVar(checks, tok.varId());
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else if (tok.strAt(-2) != ">" || !tok.linkAt(-2))
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use(checks, &tok);
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//use_array(checks, &tok);
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return &tok;
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}
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// Used..
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if (Token::Match(tok.previous(), "[[(,+-*/|=] %var% ]|)|,|;|%op%")) {
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// Taking address of array..
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std::list<ExecutionPath *>::const_iterator it;
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for (it = checks.begin(); it != checks.end(); ++it) {
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == tok.varId()) {
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if (c->var->isArray())
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bailOutVar(checks, tok.varId());
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break;
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}
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}
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// initialize reference variable
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if (Token::Match(tok.tokAt(-3), "& %var% ="))
|
|
bailOutVar(checks, tok.varId());
|
|
else
|
|
use(checks, &tok);
|
|
return &tok;
|
|
}
|
|
|
|
if ((tok.previous() && tok.previous()->type() == Token::eIncDecOp) || (tok.next() && tok.next()->type() == Token::eIncDecOp)) {
|
|
use(checks, &tok);
|
|
return &tok;
|
|
}
|
|
|
|
if (Token::Match(tok.previous(), "[;{}] %var% [=[.]")) {
|
|
if (tok.next()->str() == ".") {
|
|
if (use_dead_pointer(checks, &tok)) {
|
|
return &tok;
|
|
}
|
|
} else {
|
|
const Token *tok2 = tok.next();
|
|
|
|
if (tok2->str() == "[") {
|
|
const Token *tok3 = tok2->link();
|
|
while (Token::simpleMatch(tok3, "] ["))
|
|
tok3 = tok3->next()->link();
|
|
|
|
// Possible initialization
|
|
if (Token::simpleMatch(tok3, "] >>"))
|
|
return &tok;
|
|
|
|
if (Token::simpleMatch(tok3, "] =")) {
|
|
if (use_dead_pointer(checks, &tok)) {
|
|
return &tok;
|
|
}
|
|
|
|
parserhs(tok2, checks);
|
|
tok2 = tok3->next();
|
|
}
|
|
}
|
|
|
|
parserhs(tok2, checks);
|
|
}
|
|
|
|
// pointer aliasing?
|
|
if (Token::Match(tok.tokAt(2), "%var% ;")) {
|
|
pointer_assignment(checks, &tok, tok.tokAt(2));
|
|
}
|
|
}
|
|
|
|
if (Token::simpleMatch(tok.next(), "(")) {
|
|
use_pointer(checks, &tok);
|
|
}
|
|
|
|
if (Token::Match(tok.tokAt(-2), "[;{}] *")) {
|
|
if (Token::simpleMatch(tok.next(), "=")) {
|
|
// is the pointer used in the rhs?
|
|
bool used = false;
|
|
for (const Token *tok2 = tok.tokAt(2); tok2; tok2 = tok2->next()) {
|
|
if (Token::Match(tok2, "[,;=(]"))
|
|
break;
|
|
else if (Token::Match(tok2, "* %varid%", tok.varId())) {
|
|
used = true;
|
|
break;
|
|
}
|
|
}
|
|
if (used)
|
|
use_pointer(checks, &tok);
|
|
else
|
|
init_pointer(checks, &tok);
|
|
} else {
|
|
use_pointer(checks, &tok);
|
|
}
|
|
return &tok;
|
|
}
|
|
|
|
if (Token::Match(tok.next(), "= malloc|kmalloc") || Token::simpleMatch(tok.next(), "= new char [")) {
|
|
alloc_pointer(checks, tok.varId());
|
|
if (tok.strAt(3) == "(")
|
|
return tok.tokAt(3);
|
|
}
|
|
|
|
else if ((!isC && (Token::Match(tok.previous(), "<<|>>") || Token::Match(tok.previous(), "[;{}] %var% <<"))) ||
|
|
Token::simpleMatch(tok.next(), "=")) {
|
|
// TODO: Don't bail out for "<<" and ">>" if these are
|
|
// just computations
|
|
ExecutionPath::bailOutVar(checks, tok.varId());
|
|
return &tok;
|
|
}
|
|
|
|
if (Token::simpleMatch(tok.next(), "[")) {
|
|
const Token *tok2 = tok.next()->link();
|
|
if (Token::simpleMatch(tok2 ? tok2->next() : 0, "=")) {
|
|
ExecutionPath::bailOutVar(checks, tok.varId());
|
|
return &tok;
|
|
}
|
|
}
|
|
|
|
if (Token::simpleMatch(tok.previous(), "delete") ||
|
|
Token::simpleMatch(tok.tokAt(-3), "delete [ ]")) {
|
|
dealloc_pointer(checks, &tok);
|
|
return &tok;
|
|
}
|
|
}
|
|
|
|
if (Token::Match(&tok, "%var% (") && uvarFunctions.find(tok.str()) == uvarFunctions.end()) {
|
|
// sizeof/typeof doesn't dereference. A function name that is all uppercase
|
|
// might be an unexpanded macro that uses sizeof/typeof
|
|
if (Token::Match(&tok, "sizeof|typeof ("))
|
|
return tok.next()->link();
|
|
|
|
// deallocate pointer
|
|
if (Token::Match(&tok, "free|kfree|fclose ( %var% )") ||
|
|
Token::Match(&tok, "realloc ( %var%")) {
|
|
dealloc_pointer(checks, tok.tokAt(2));
|
|
return tok.tokAt(3);
|
|
}
|
|
|
|
// parse usage..
|
|
{
|
|
std::list<const Token *> var1;
|
|
CheckNullPointer::parseFunctionCall(tok, var1, 1);
|
|
for (std::list<const Token *>::const_iterator it = var1.begin(); it != var1.end(); ++it) {
|
|
// does iterator point at first function parameter?
|
|
const bool firstPar(*it == tok.tokAt(2));
|
|
|
|
// is function memset/memcpy/etc?
|
|
if (tok.str().compare(0,3,"mem") == 0)
|
|
use_array_mem(checks, *it);
|
|
|
|
// second parameter for strncpy/strncat/etc
|
|
else if (!firstPar && tok.str().compare(0,4,"strn") == 0)
|
|
use_array_mem(checks, *it);
|
|
|
|
else
|
|
use_array(checks, *it);
|
|
|
|
use_dead_pointer(checks, *it);
|
|
}
|
|
|
|
// Using uninitialized pointer is bad if using null pointer is bad
|
|
std::list<const Token *> var2;
|
|
CheckNullPointer::parseFunctionCall(tok, var2, 0);
|
|
for (std::list<const Token *>::const_iterator it = var2.begin(); it != var2.end(); ++it) {
|
|
if (std::find(var1.begin(), var1.end(), *it) == var1.end())
|
|
use_dead_pointer(checks, *it);
|
|
}
|
|
}
|
|
|
|
// strncpy doesn't null-terminate first parameter
|
|
if (Token::Match(&tok, "strncpy ( %var% ,")) {
|
|
if (Token::Match(tok.tokAt(4), "%str% ,")) {
|
|
if (Token::Match(tok.tokAt(6), "%num% )")) {
|
|
const std::size_t len = Token::getStrLength(tok.tokAt(4));
|
|
const MathLib::bigint sz = MathLib::toLongNumber(tok.strAt(6));
|
|
if (sz >= 0 && len >= static_cast<unsigned long>(sz)) {
|
|
init_strncpy(checks, tok.tokAt(2));
|
|
return tok.next()->link();
|
|
}
|
|
}
|
|
} else {
|
|
init_strncpy(checks, tok.tokAt(2));
|
|
return tok.next()->link();
|
|
}
|
|
}
|
|
|
|
// memset (not zero terminated)..
|
|
if (Token::Match(&tok, "memset ( %var% , !!0 , %num% )")) {
|
|
init_memset_nonzero(checks, tok.tokAt(2));
|
|
return tok.next()->link();
|
|
}
|
|
|
|
if (Token::Match(&tok, "asm ( %str% )")) {
|
|
ExecutionPath::bailOut(checks);
|
|
return &tok;
|
|
}
|
|
|
|
// is the variable passed as a parameter to some function?
|
|
unsigned int parlevel = 0;
|
|
std::set<unsigned int> bailouts;
|
|
for (const Token *tok2 = tok.next(); tok2; tok2 = tok2->next()) {
|
|
if (tok2->str() == "(")
|
|
++parlevel;
|
|
|
|
else if (tok2->str() == ")") {
|
|
if (parlevel <= 1)
|
|
break;
|
|
--parlevel;
|
|
}
|
|
|
|
else if (Token::Match(tok2, "sizeof|typeof (")) {
|
|
tok2 = tok2->next()->link();
|
|
if (!tok2)
|
|
break;
|
|
}
|
|
|
|
// ticket #2367 : unexpanded macro that uses sizeof|typeof?
|
|
else if (Token::Match(tok2, "%type% (") && tok2->isUpperCaseName()) {
|
|
tok2 = tok2->next()->link();
|
|
if (!tok2)
|
|
break;
|
|
}
|
|
|
|
else if (tok2->varId()) {
|
|
if (Token::Match(tok2->tokAt(-2), "[(,] *") || Token::Match(tok2->next(), ". %var%")) {
|
|
// find function call..
|
|
const Token *functionCall = tok2;
|
|
while (NULL != (functionCall = functionCall ? functionCall->previous() : 0)) {
|
|
if (functionCall->str() == "(")
|
|
break;
|
|
if (functionCall->str() == ")")
|
|
functionCall = functionCall->link();
|
|
}
|
|
|
|
functionCall = functionCall ? functionCall->previous() : 0;
|
|
if (functionCall) {
|
|
if (functionCall->isName() && !functionCall->isUpperCaseName() && use_dead_pointer(checks, tok2))
|
|
ExecutionPath::bailOutVar(checks, tok2->varId());
|
|
}
|
|
}
|
|
|
|
// it is possible that the variable is initialized here
|
|
if (Token::Match(tok2->previous(), "[(,] %var% [,)]"))
|
|
bailouts.insert(tok2->varId());
|
|
|
|
// array initialization..
|
|
if (Token::Match(tok2->previous(), "[,(] %var% [+-]")) {
|
|
// if var is array, bailout
|
|
for (std::list<ExecutionPath *>::const_iterator it = checks.begin(); it != checks.end(); ++it) {
|
|
if ((*it)->varId == tok2->varId()) {
|
|
const UninitVar *c = dynamic_cast<const UninitVar *>(*it);
|
|
if (c && (c->var->isArray() || (c->var->isPointer() && c->alloc)))
|
|
bailouts.insert(tok2->varId());
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
for (std::set<unsigned int>::const_iterator it = bailouts.begin(); it != bailouts.end(); ++it)
|
|
ExecutionPath::bailOutVar(checks, *it);
|
|
}
|
|
|
|
// function call via function pointer
|
|
if (Token::Match(&tok, "( * %var% ) (") ||
|
|
(Token::Match(&tok, "( *| %var% .|::") && Token::Match(tok.link()->tokAt(-2), ".|:: %var% ) ("))) {
|
|
// is the variable passed as a parameter to some function?
|
|
const Token *tok2 = tok.link()->next();
|
|
for (const Token* const end2 = tok2->link(); tok2 != end2; tok2 = tok2->next()) {
|
|
if (tok2->varId()) {
|
|
// it is possible that the variable is initialized here
|
|
ExecutionPath::bailOutVar(checks, tok2->varId());
|
|
}
|
|
}
|
|
}
|
|
|
|
if (tok.str() == "return") {
|
|
// Todo: if (!array && ..
|
|
if (Token::Match(tok.next(), "%var% ;")) {
|
|
use(checks, tok.next());
|
|
} else if (Token::Match(tok.next(), "%var% [")) {
|
|
use_array_or_pointer_data(checks, tok.next());
|
|
}
|
|
}
|
|
|
|
if (tok.varId()) {
|
|
if (Token::simpleMatch(tok.previous(), "=")) {
|
|
if (Token::Match(tok.tokAt(-3), "& %var% =")) {
|
|
bailOutVar(checks, tok.varId());
|
|
return &tok;
|
|
}
|
|
|
|
if (!Token::Match(tok.tokAt(-3), ". %var% =")) {
|
|
if (!Token::Match(tok.tokAt(-3), "[;{}] %var% =")) {
|
|
use(checks, &tok);
|
|
return &tok;
|
|
}
|
|
|
|
const unsigned int varid2 = tok.tokAt(-2)->varId();
|
|
if (varid2) {
|
|
{
|
|
use(checks, &tok);
|
|
return &tok;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (Token::simpleMatch(tok.next(), ".")) {
|
|
bailOutVar(checks, tok.varId());
|
|
return &tok;
|
|
}
|
|
|
|
if (Token::simpleMatch(tok.next(), "[")) {
|
|
ExecutionPath::bailOutVar(checks, tok.varId());
|
|
return &tok;
|
|
}
|
|
|
|
if (Token::Match(tok.tokAt(-2), "[,(=] *")) {
|
|
use_pointer(checks, &tok);
|
|
return &tok;
|
|
}
|
|
|
|
if (Token::simpleMatch(tok.previous(), "&")) {
|
|
ExecutionPath::bailOutVar(checks, tok.varId());
|
|
}
|
|
}
|
|
|
|
// Parse "for"
|
|
if (Token::Match(&tok, "[;{}] for (")) {
|
|
// initialized variables
|
|
std::set<unsigned int> varid1;
|
|
varid1.insert(0);
|
|
|
|
// Parse token
|
|
const Token *tok2;
|
|
|
|
// parse setup
|
|
for (tok2 = tok.tokAt(3); tok2 != tok.link(); tok2 = tok2->next()) {
|
|
if (tok2->str() == ";")
|
|
break;
|
|
if (tok2->varId())
|
|
varid1.insert(tok2->varId());
|
|
}
|
|
if (tok2 == tok.link())
|
|
return &tok;
|
|
|
|
// parse condition
|
|
if (Token::Match(tok2, "; %var% <|<=|>=|> %num% ;")) {
|
|
// If the variable hasn't been initialized then call "use"
|
|
if (varid1.find(tok2->next()->varId()) == varid1.end())
|
|
use(checks, tok2->next());
|
|
}
|
|
|
|
// goto stepcode
|
|
tok2 = tok2->next();
|
|
while (tok2 && tok2->str() != ";")
|
|
tok2 = tok2->next();
|
|
|
|
// parse the stepcode
|
|
if (Token::Match(tok2, "; ++|-- %var% ) {") ||
|
|
Token::Match(tok2, "; %var% ++|-- ) {")) {
|
|
// get id of variable..
|
|
unsigned int varid = tok2->next()->varId();
|
|
if (!varid)
|
|
varid = tok2->tokAt(2)->varId();
|
|
|
|
// Check that the variable hasn't been initialized and
|
|
// that it isn't initialized in the body..
|
|
if (varid1.find(varid) == varid1.end()) {
|
|
for (const Token *tok3 = tok2->tokAt(5); tok3 && tok3 != tok2->linkAt(4); tok3 = tok3->next()) {
|
|
if (tok3->varId() == varid) {
|
|
varid = 0; // variable is used.. maybe it's initialized. clear the variable id.
|
|
break;
|
|
}
|
|
}
|
|
|
|
// If the variable isn't initialized in the body call "use"
|
|
if (varid != 0) {
|
|
// goto variable
|
|
tok2 = tok2->next();
|
|
if (!tok2->varId())
|
|
tok2 = tok2->next();
|
|
|
|
// call "use"
|
|
use(checks, tok2);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return &tok;
|
|
}
|
|
|
|
bool parseCondition(const Token &tok, std::list<ExecutionPath *> &checks) {
|
|
if (tok.varId() && Token::Match(&tok, "%var% <|<=|==|!=|)"))
|
|
use(checks, &tok);
|
|
|
|
else if (Token::Match(&tok, "!| %var% [") && !Token::simpleMatch(skipBrackets(tok.next()), "="))
|
|
use_array_or_pointer_data(checks, tok.str() == "!" ? tok.next() : &tok);
|
|
|
|
else if (Token::Match(&tok, "!| %var% (")) {
|
|
const Token * const ftok = (tok.str() == "!") ? tok.next() : &tok;
|
|
std::list<const Token *> var1;
|
|
CheckNullPointer::parseFunctionCall(*ftok, var1, 1);
|
|
for (std::list<const Token *>::const_iterator it = var1.begin(); it != var1.end(); ++it) {
|
|
// is function memset/memcpy/etc?
|
|
if (ftok->str().compare(0,3,"mem") == 0)
|
|
use_array_mem(checks, *it);
|
|
else
|
|
use_array(checks, *it);
|
|
}
|
|
}
|
|
|
|
else if (Token::Match(&tok, "! %var% )")) {
|
|
use(checks, &tok);
|
|
return false;
|
|
}
|
|
|
|
return ExecutionPath::parseCondition(tok, checks);
|
|
}
|
|
|
|
void parseLoopBody(const Token *tok, std::list<ExecutionPath *> &checks) const {
|
|
while (tok) {
|
|
if (tok->str() == "{" || tok->str() == "}" || tok->str() == "for")
|
|
return;
|
|
if (Token::simpleMatch(tok, "if (")) {
|
|
// bail out all variables that are used in the condition
|
|
const Token* const end2 = tok->linkAt(1);
|
|
for (const Token *tok2 = tok->tokAt(2); tok2 != end2; tok2 = tok2->next()) {
|
|
if (tok2->varId())
|
|
ExecutionPath::bailOutVar(checks, tok2->varId());
|
|
}
|
|
}
|
|
const Token *next = parse(*tok, checks);
|
|
tok = next->next();
|
|
}
|
|
}
|
|
|
|
public:
|
|
|
|
/** Functions that don't handle uninitialized variables well */
|
|
static std::set<std::string> uvarFunctions;
|
|
|
|
static void analyseFunctions(const Token * const tokens, std::set<std::string> &func) {
|
|
for (const Token *tok = tokens; tok; tok = tok->next()) {
|
|
if (tok->str() == "{") {
|
|
tok = tok->link();
|
|
continue;
|
|
}
|
|
if (tok->str() != "::" && Token::Match(tok->next(), "%var% ( %type%")) {
|
|
if (!Token::Match(tok->linkAt(2), ") [{;]"))
|
|
continue;
|
|
const Token *tok2 = tok->tokAt(3);
|
|
while (tok2 && tok2->str() != ")") {
|
|
if (tok2->str() == ",")
|
|
tok2 = tok2->next();
|
|
|
|
if (Token::Match(tok2, "%type% %var% ,|)") && tok2->isStandardType()) {
|
|
tok2 = tok2->tokAt(2);
|
|
continue;
|
|
}
|
|
|
|
if (tok2->isStandardType() && Token::Match(tok2, "%type% & %var% ,|)")) {
|
|
const unsigned int varid(tok2->tokAt(2)->varId());
|
|
|
|
// flags for read/write
|
|
bool r = false, w = false;
|
|
|
|
// check how the variable is used in the function
|
|
unsigned int indentlevel = 0;
|
|
for (const Token *tok3 = tok2; tok3; tok3 = tok3->next()) {
|
|
if (tok3->str() == "{")
|
|
++indentlevel;
|
|
else if (tok3->str() == "}") {
|
|
if (indentlevel <= 1)
|
|
break;
|
|
--indentlevel;
|
|
} else if (indentlevel == 0 && tok3->str() == ";")
|
|
break;
|
|
else if (indentlevel >= 1 && tok3->varId() == varid) {
|
|
if (tok3->previous()->type() == Token::eIncDecOp ||
|
|
tok3->next()->type() == Token::eIncDecOp) {
|
|
r = true;
|
|
}
|
|
|
|
else {
|
|
w = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!r || w)
|
|
break;
|
|
|
|
tok2 = tok2->tokAt(3);
|
|
continue;
|
|
}
|
|
|
|
if (Token::Match(tok2, "const %type% &|*| const| %var% ,|)") && tok2->next()->isStandardType()) {
|
|
tok2 = tok2->tokAt(3);
|
|
while (tok2->isName())
|
|
tok2 = tok2->next();
|
|
continue;
|
|
}
|
|
|
|
if (Token::Match(tok2, "const %type% %var% [ ] ,|)") && tok2->next()->isStandardType()) {
|
|
tok2 = tok2->tokAt(5);
|
|
continue;
|
|
}
|
|
|
|
/// @todo enable this code. if pointer is written in function then dead pointer is invalid but valid pointer is ok.
|
|
/*
|
|
if (Token::Match(tok2, "const| struct| %type% * %var% ,|)"))
|
|
{
|
|
while (tok2->isName())
|
|
tok2 = tok2->next();
|
|
tok2 = tok2->tokAt(2);
|
|
continue;
|
|
}
|
|
*/
|
|
|
|
break;
|
|
}
|
|
|
|
// found simple function..
|
|
if (tok2 && tok2->link() == tok->tokAt(2))
|
|
func.insert(tok->next()->str());
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
/** Functions that don't handle uninitialized variables well */
|
|
std::set<std::string> UninitVar::uvarFunctions;
|
|
|
|
|
|
/// @}
|
|
|
|
|
|
void CheckUninitVar::analyse(const Token * tokens, std::set<std::string> &func) const
|
|
{
|
|
UninitVar::analyseFunctions(tokens, func);
|
|
}
|
|
|
|
void CheckUninitVar::saveAnalysisData(const std::set<std::string> &data) const
|
|
{
|
|
UninitVar::uvarFunctions.insert(data.begin(), data.end());
|
|
}
|
|
|
|
void CheckUninitVar::executionPaths()
|
|
{
|
|
// check if variable is accessed uninitialized..
|
|
{
|
|
// no writing if multiple threads are used (TODO: thread safe analysis?)
|
|
if (_settings->_jobs == 1)
|
|
UninitVar::analyseFunctions(_tokenizer->tokens(), UninitVar::uvarFunctions);
|
|
|
|
UninitVar c(this, _tokenizer->getSymbolDatabase(), _tokenizer->isC());
|
|
checkExecutionPaths(_tokenizer->getSymbolDatabase(), &c);
|
|
}
|
|
}
|
|
|
|
|
|
void CheckUninitVar::check()
|
|
{
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
std::list<Scope>::const_iterator func_scope;
|
|
|
|
// scan every function
|
|
for (func_scope = symbolDatabase->scopeList.begin(); func_scope != symbolDatabase->scopeList.end(); ++func_scope) {
|
|
// only check functions
|
|
if (func_scope->type == Scope::eFunction) {
|
|
checkScope(&*func_scope);
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckUninitVar::checkScope(const Scope* scope)
|
|
{
|
|
for (std::list<Variable>::const_iterator i = scope->varlist.begin(); i != scope->varlist.end(); ++i) {
|
|
if ((_tokenizer->isCPP() && i->type() && !i->isPointer()) || i->isStatic() || i->isExtern() || i->isConst() || i->isArray() || i->isReference())
|
|
continue;
|
|
if (i->nameToken()->strAt(1) == "(")
|
|
continue;
|
|
|
|
bool forHead = false; // Don't check variables declared in header of a for loop
|
|
for (const Token* tok = i->typeStartToken(); tok; tok = tok->previous()) {
|
|
if (tok->str() == "(") {
|
|
forHead = true;
|
|
break;
|
|
} else if (tok->str() == "{" || tok->str() == ";" || tok->str() == "}")
|
|
break;
|
|
}
|
|
if (forHead)
|
|
continue;
|
|
|
|
bool stdtype = _tokenizer->isC();
|
|
const Token* tok = i->typeStartToken();
|
|
for (; tok && tok->str() != ";" && tok->str() != "<"; tok = tok->next()) {
|
|
if (tok->isStandardType())
|
|
stdtype = true;
|
|
}
|
|
while (tok && tok->str() != ";")
|
|
tok = tok->next();
|
|
if (stdtype || i->isPointer())
|
|
checkScopeForVariable(scope, tok, *i, NULL, NULL, NULL);
|
|
if (_settings->experimental && Token::Match(i->typeStartToken(), "struct %type% %var% ;")) {
|
|
const std::string structname(i->typeStartToken()->next()->str());
|
|
const SymbolDatabase * symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
for (std::size_t j = 0U; j < symbolDatabase->classAndStructScopes.size(); ++j) {
|
|
const Scope *scope2 = symbolDatabase->classAndStructScopes[j];
|
|
if (scope2->className == structname && scope2->numConstructors == 0U) {
|
|
for (std::list<Variable>::const_iterator it = scope2->varlist.begin(); it != scope2->varlist.end(); ++it)
|
|
checkScopeForVariable(scope, tok, *i, NULL, NULL, &(*it));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
for (std::list<Scope*>::const_iterator i = scope->nestedList.begin(); i != scope->nestedList.end(); ++i) {
|
|
if (!(*i)->isClassOrStruct())
|
|
checkScope(*i);
|
|
}
|
|
}
|
|
|
|
bool CheckUninitVar::checkScopeForVariable(const Scope* scope, const Token *tok, const Variable& var, bool * const possibleInit, bool * const noreturn, const Variable * const membervar)
|
|
{
|
|
const bool suppressErrors(possibleInit && *possibleInit);
|
|
|
|
if (possibleInit)
|
|
*possibleInit = false;
|
|
|
|
unsigned int number_of_if = 0;
|
|
|
|
// variable values
|
|
std::map<unsigned int, int> variableValue;
|
|
static const int NOT_ZERO = (1<<30); // special variable value
|
|
|
|
for (; tok; tok = tok->next()) {
|
|
// End of scope..
|
|
if (tok->str() == "}") {
|
|
if (number_of_if && possibleInit)
|
|
*possibleInit = true;
|
|
|
|
// might be a noreturn function..
|
|
if (_tokenizer->IsScopeNoReturn(tok))
|
|
return true;
|
|
|
|
break;
|
|
}
|
|
|
|
// Unconditional inner scope..
|
|
if (tok->str() == "{" && Token::Match(tok->previous(), "[;{}]")) {
|
|
if (checkScopeForVariable(scope, tok->next(), var, possibleInit, NULL, membervar))
|
|
return true;
|
|
tok = tok->link();
|
|
continue;
|
|
}
|
|
|
|
// assignment with nonzero constant..
|
|
if (Token::Match(tok->previous(), "[;{}] %var% = - %var% ;") && tok->varId() > 0)
|
|
variableValue[tok->varId()] = NOT_ZERO;
|
|
|
|
// Inner scope..
|
|
if (Token::simpleMatch(tok, "if (")) {
|
|
bool alwaysTrue = false;
|
|
|
|
// known variable in condition..
|
|
if (Token::Match(tok, "if ( !| %var% %oror%")) {
|
|
const Token *vartok = tok->tokAt(2);
|
|
if (vartok->str() == "!")
|
|
vartok = vartok->next();
|
|
std::map<unsigned int, int>::const_iterator it = variableValue.find(vartok->varId());
|
|
if (tok->strAt(2) == "!")
|
|
alwaysTrue = bool(it != variableValue.end() && it->second == 0);
|
|
else
|
|
alwaysTrue = bool(it != variableValue.end() && it->second != 0);
|
|
}
|
|
|
|
// initialization / usage in condition..
|
|
if (!alwaysTrue && checkIfForWhileHead(scope, tok->next(), var, suppressErrors, bool(number_of_if == 0)))
|
|
return true;
|
|
|
|
// checking if a not-zero variable is zero => bail out
|
|
unsigned int condVarId = 0, condVarValue = 0;
|
|
if (Token::Match(tok, "if ( %var% )")) {
|
|
std::map<unsigned int,int>::const_iterator it = variableValue.find(tok->tokAt(2)->varId());
|
|
if (it != variableValue.end() && it->second == NOT_ZERO)
|
|
return true; // this scope is not fully analysed => return true
|
|
else {
|
|
condVarId = tok->tokAt(2)->varId();
|
|
condVarValue = NOT_ZERO;
|
|
}
|
|
}
|
|
|
|
// goto the {
|
|
tok = tok->next()->link()->next();
|
|
|
|
if (!tok)
|
|
break;
|
|
if (tok->str() == "{") {
|
|
bool possibleInitIf(number_of_if > 0 || suppressErrors);
|
|
bool noreturnIf = false;
|
|
const bool initif = !alwaysTrue && checkScopeForVariable(scope, tok->next(), var, &possibleInitIf, &noreturnIf, membervar);
|
|
|
|
// bail out for such code:
|
|
// if (a) x=0; // conditional initialization
|
|
// if (b) return; // cppcheck doesn't know if b can be false when a is false.
|
|
// x++; // it's possible x is always initialized
|
|
if (!alwaysTrue && noreturnIf && number_of_if > 0) {
|
|
if (_settings->debugwarnings) {
|
|
std::string condition;
|
|
for (const Token *tok2 = tok->linkAt(-1); tok2 != tok; tok2 = tok2->next()) {
|
|
condition += tok2->str();
|
|
if (tok2->isName() && tok2->next()->isName())
|
|
condition += ' ';
|
|
}
|
|
reportError(tok, Severity::debug, "debug", "uninitialized variables: bailout. can't determine if this condition can be false when previous condition is false: " + condition);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
std::map<unsigned int, int> varValueIf;
|
|
if (!initif) {
|
|
for (const Token *tok2 = tok; tok2 && tok2 != tok->link(); tok2 = tok2->next()) {
|
|
if (Token::Match(tok2, "[;{}] %var% = - %var% ;"))
|
|
varValueIf[tok2->next()->varId()] = NOT_ZERO;
|
|
if (Token::Match(tok2, "[;{}] %var% = %num% ;"))
|
|
varValueIf[tok2->next()->varId()] = (int)MathLib::toLongNumber(tok2->strAt(3));
|
|
}
|
|
}
|
|
|
|
if (initif && condVarId > 0U)
|
|
variableValue[condVarId] = condVarValue ^ NOT_ZERO;
|
|
|
|
// goto the }
|
|
tok = tok->link();
|
|
|
|
if (!Token::simpleMatch(tok, "} else {")) {
|
|
if (initif || possibleInitIf) {
|
|
++number_of_if;
|
|
if (number_of_if >= 2)
|
|
return true;
|
|
}
|
|
} else {
|
|
// goto the {
|
|
tok = tok->tokAt(2);
|
|
|
|
bool possibleInitElse(number_of_if > 0 || suppressErrors);
|
|
bool noreturnElse = false;
|
|
const bool initelse = checkScopeForVariable(scope, tok->next(), var, &possibleInitElse, NULL, membervar);
|
|
|
|
std::map<unsigned int, int> varValueElse;
|
|
if (!initelse) {
|
|
for (const Token *tok2 = tok; tok2 && tok2 != tok->link(); tok2 = tok2->next()) {
|
|
if (Token::Match(tok2, "[;{}] %var% = - %var% ;"))
|
|
varValueElse[tok2->next()->varId()] = NOT_ZERO;
|
|
if (Token::Match(tok2, "[;{}] %var% = %num% ;"))
|
|
varValueElse[tok2->next()->varId()] = (int)MathLib::toLongNumber(tok2->strAt(3));
|
|
}
|
|
}
|
|
|
|
|
|
if (initelse && condVarId > 0U)
|
|
variableValue[condVarId] = condVarValue;
|
|
|
|
// goto the }
|
|
tok = tok->link();
|
|
|
|
if (initif && initelse)
|
|
return true;
|
|
|
|
if ((initif && noreturnElse) || (initelse && noreturnIf))
|
|
return true;
|
|
|
|
if (initif || initelse || possibleInitElse) {
|
|
++number_of_if;
|
|
variableValue.insert(varValueIf.begin(), varValueIf.end());
|
|
variableValue.insert(varValueElse.begin(), varValueElse.end());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// = { .. }
|
|
if (Token::simpleMatch(tok, "= {")) {
|
|
// end token
|
|
const Token *end = tok->next()->link();
|
|
|
|
// If address of variable is taken in the block then bail out
|
|
if (Token::findmatch(tok->tokAt(2), "& %varid%", end, var.varId()))
|
|
return true;
|
|
|
|
// Skip block
|
|
tok = end;
|
|
continue;
|
|
}
|
|
|
|
// skip sizeof / offsetof
|
|
if (Token::Match(tok, "sizeof|typeof|offsetof|decltype ("))
|
|
tok = tok->next()->link();
|
|
|
|
// for/while..
|
|
if (Token::Match(tok, "for|while (")) {
|
|
// is variable initialized in for-head (don't report errors yet)?
|
|
if (checkIfForWhileHead(scope, tok->next(), var, true, false))
|
|
return true;
|
|
|
|
// goto the {
|
|
const Token *tok2 = tok->next()->link()->next();
|
|
|
|
if (tok2 && tok2->str() == "{") {
|
|
bool possibleinit = true;
|
|
bool init = checkScopeForVariable(scope, tok2->next(), var, &possibleinit, NULL, membervar);
|
|
|
|
// variable is initialized in the loop..
|
|
if (possibleinit || init)
|
|
return true;
|
|
|
|
// is variable used in for-head?
|
|
if (!suppressErrors) {
|
|
checkIfForWhileHead(scope, tok->next(), var, false, bool(number_of_if == 0));
|
|
}
|
|
|
|
// goto "}"
|
|
tok = tok2->link();
|
|
}
|
|
}
|
|
|
|
// TODO: handle loops, try, etc
|
|
if (Token::simpleMatch(tok, ") {") || Token::Match(tok, "%var% {")) {
|
|
return true;
|
|
}
|
|
|
|
// bailout if there is assembler code
|
|
if (Token::simpleMatch(tok, "asm (")) {
|
|
return true;
|
|
}
|
|
|
|
if (Token::Match(tok, "return|break|continue|throw|goto")) {
|
|
if (noreturn)
|
|
*noreturn = true;
|
|
|
|
while (tok && tok->str() != ";") {
|
|
// variable is seen..
|
|
if (tok->varId() == var.varId()) {
|
|
// Use variable
|
|
if (!suppressErrors && isVariableUsage(scope, tok, var.isPointer()))
|
|
uninitvarError(tok, tok->str());
|
|
|
|
else
|
|
// assume that variable is assigned
|
|
return true;
|
|
}
|
|
|
|
else if (Token::Match(tok, "sizeof|typeof|offsetof|decltype ("))
|
|
tok = tok->linkAt(1);
|
|
|
|
tok = tok->next();
|
|
}
|
|
|
|
return bool(noreturn==NULL);
|
|
}
|
|
|
|
// variable is seen..
|
|
if (tok->varId() == var.varId()) {
|
|
if (membervar) {
|
|
if (Token::Match(tok, "%var% . %var% =") && tok->strAt(2) == membervar->name())
|
|
return true;
|
|
else if (Token::Match(tok, "%var% ="))
|
|
return true;
|
|
else if (Token::Match(tok->previous(), "[(,] %var% [,)]") && isVariableUsage(scope, tok, var.isPointer()))
|
|
uninitvarError(tok, tok->str() + "." + membervar->name());
|
|
} else {
|
|
// Use variable
|
|
if (!suppressErrors && isVariableUsage(scope, tok, var.isPointer()))
|
|
uninitvarError(tok, tok->str());
|
|
|
|
else
|
|
// assume that variable is assigned
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool CheckUninitVar::checkIfForWhileHead(const Scope *scope, const Token *startparentheses, const Variable& var, bool suppressErrors, bool isuninit)
|
|
{
|
|
const Token * const endpar = startparentheses->link();
|
|
for (const Token *tok = startparentheses->next(); tok && tok != endpar; tok = tok->next()) {
|
|
if (tok->varId() == var.varId()) {
|
|
if (isVariableUsage(scope, tok, var.isPointer())) {
|
|
if (!suppressErrors)
|
|
uninitvarError(tok, tok->str());
|
|
else
|
|
continue;
|
|
}
|
|
return true;
|
|
}
|
|
if (Token::Match(tok, "sizeof|decltype|offsetof ("))
|
|
tok = tok->next()->link();
|
|
if (!isuninit && tok->str() == "&&")
|
|
suppressErrors = true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool CheckUninitVar::isVariableUsage(const Scope* scope, const Token *vartok, bool pointer) const
|
|
{
|
|
if (vartok->previous()->str() == "return")
|
|
return true;
|
|
|
|
// Passing variable to function..
|
|
if (Token::Match(vartok->previous(), "[(,] %var% [,)]") || Token::Match(vartok->tokAt(-2), "[(,] & %var% [,)]")) {
|
|
const bool address(vartok->previous()->str() == "&");
|
|
|
|
// locate start parentheses in function call..
|
|
int argumentNumber = 0;
|
|
const Token *start = vartok;
|
|
while (start && !Token::Match(start, "[;{}(]")) {
|
|
if (start->str() == ")")
|
|
start = start->link();
|
|
else if (start->str() == ",")
|
|
++argumentNumber;
|
|
start = start->previous();
|
|
}
|
|
|
|
// is this a function call?
|
|
if (start && Token::Match(start->previous(), "%var% (")) {
|
|
// check how function handle uninitialized data arguments..
|
|
const Function *func = _tokenizer->getSymbolDatabase()->findFunctionByNameAndArgs(start->previous(), scope);
|
|
if (func) {
|
|
const Variable *arg = func->getArgumentVar(argumentNumber);
|
|
if (arg) {
|
|
const Token *argStart = arg->typeStartToken();
|
|
while (argStart->previous() && argStart->previous()->isName())
|
|
argStart = argStart->previous();
|
|
if (!address && Token::Match(argStart, "const| struct| %type% %var% [,)]"))
|
|
return true;
|
|
if (Token::Match(argStart, "const %type% & %var% [,)]"))
|
|
return true;
|
|
if (pointer && !address && Token::Match(argStart, "%type% * %var% [,)]"))
|
|
return true;
|
|
if ((pointer || address) && Token::Match(argStart, "const %type% * %var% [,)]"))
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (Token::Match(vartok->previous(), "++|--|%op%")) {
|
|
if (vartok->previous()->str() == ">>" && _tokenizer->isCPP()) {
|
|
// assume that variable is initialized
|
|
return false;
|
|
}
|
|
|
|
// is there something like: ; "*((&var ..expr.. =" => the variable is assigned
|
|
if (vartok->previous()->str() == "&") {
|
|
const Token *tok2 = vartok->tokAt(-2);
|
|
if (tok2 && (tok2->isOp() || tok2->str() == "("))
|
|
return false; // address of
|
|
if (Token::simpleMatch(tok2,")"))
|
|
tok2 = tok2->link()->previous();
|
|
while (tok2 && tok2->str() == "(")
|
|
tok2 = tok2->previous();
|
|
while (tok2 && tok2->str() == "*")
|
|
tok2 = tok2->previous();
|
|
if (Token::Match(tok2, "[;{}] *")) {
|
|
// there is some such code before vartok: "[*]+ [(]* &"
|
|
// determine if there is a = after vartok
|
|
for (tok2 = vartok; tok2; tok2 = tok2->next()) {
|
|
if (Token::Match(tok2, "[;{}]"))
|
|
break;
|
|
if (tok2->str() == "=")
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (vartok->previous()->str() != "&" || !Token::Match(vartok->tokAt(-2), "[(,=?:]")) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool unknown = false;
|
|
if (pointer && CheckNullPointer::isPointerDeRef(vartok, unknown, _tokenizer->getSymbolDatabase())) {
|
|
// function parameter?
|
|
bool functionParameter = false;
|
|
if (Token::Match(vartok->tokAt(-2), "%var% (") || vartok->previous()->str() == ",")
|
|
functionParameter = true;
|
|
|
|
// if this is not a function parameter report this dereference as variable usage
|
|
if (!functionParameter)
|
|
return true;
|
|
}
|
|
|
|
if (_tokenizer->isCPP() && Token::Match(vartok->next(), "<<|>>")) {
|
|
// Is this calculation done in rhs?
|
|
const Token *tok = vartok;
|
|
while (tok && Token::Match(tok, "%var%|.|::"))
|
|
tok = tok->previous();
|
|
if (Token::Match(tok, "[;{}]"))
|
|
return false;
|
|
|
|
// Is variable a known POD type then this is a variable usage,
|
|
// otherwise we assume it's not.
|
|
const Variable *var = _tokenizer->getSymbolDatabase()->getVariableFromVarId(vartok->varId());
|
|
return (var && var->typeStartToken()->isStandardType());
|
|
}
|
|
|
|
if (Token::Match(vartok->next(), "++|--|%op%"))
|
|
return true;
|
|
|
|
if (vartok->strAt(1) == "]")
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
void CheckUninitVar::uninitstringError(const Token *tok, const std::string &varname, bool strncpy_)
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{
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reportError(tok, Severity::error, "uninitstring", "Dangerous usage of '" + varname + "'" + (strncpy_ ? " (strncpy doesn't always null-terminate it)." : " (not null-terminated)."));
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}
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void CheckUninitVar::uninitdataError(const Token *tok, const std::string &varname)
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{
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reportError(tok, Severity::error, "uninitdata", "Memory is allocated but not initialized: " + varname);
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}
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void CheckUninitVar::uninitvarError(const Token *tok, const std::string &varname)
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{
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reportError(tok, Severity::error, "uninitvar", "Uninitialized variable: " + varname);
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}
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