1142 lines
39 KiB
C++
1142 lines
39 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2011 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 <algorithm>
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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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{
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CheckUninitVar instance;
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}
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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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{
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public:
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/** Startup constructor */
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UninitVar(Check *c)
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: ExecutionPath(c, 0), pointer(false), array(false), alloc(false), strncpy_(false)
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{
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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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{
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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, unsigned int v, const std::string &name, bool p, bool a)
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: ExecutionPath(c, v), varname(name), pointer(p), array(a), alloc(false), strncpy_(false)
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{
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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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{
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const UninitVar *c = static_cast<const UninitVar *>(e);
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return (varname == c->varname && pointer == c->pointer && array == c->array && alloc == c->alloc && strncpy_ == c->strncpy_);
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}
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/** variable name for this check */
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const std::string varname;
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/** is this variable a pointer? */
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const bool pointer;
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/** is this variable an array? */
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const bool array;
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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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/** 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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{
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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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{
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid)
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c->alloc = true;
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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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{
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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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{
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid)
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{
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if (c->alloc || c->array)
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{
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delete c;
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checks.erase(it++);
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continue;
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}
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else
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{
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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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{
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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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{
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid)
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{
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// unallocated pointer variable => error
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if (c->pointer && !c->alloc)
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{
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CheckUninitVar *checkUninitVar = dynamic_cast<CheckUninitVar *>(c->owner);
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if (checkUninitVar)
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{
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checkUninitVar->uninitvarError(tok, c->varname);
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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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{
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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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{
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid1 && c->pointer)
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{
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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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{
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid2 && (c->pointer || c->array))
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{
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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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{
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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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{
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid)
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{
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c->strncpy_ = 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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{
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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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{
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varId == varid)
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{
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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->array || (c->pointer && c->alloc)))
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continue;
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// mode 2 : 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 == 2 && !c->pointer)
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continue;
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// mode 3 : using dead pointer is invalid.
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if (mode == 3 && (!c->pointer || c->alloc))
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continue;
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// mode 4 : reading uninitialized array or pointer is invalid.
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if (mode == 4 && (!c->array && !c->pointer))
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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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{
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if (c->strncpy_)
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checkUninitVar->uninitstringError(tok, c->varname);
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else if (c->pointer && c->alloc)
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checkUninitVar->uninitdataError(tok, c->varname);
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else
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checkUninitVar->uninitvarError(tok, c->varname);
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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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{
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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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{
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use(checks, tok, 1);
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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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{
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return use(checks, tok, 2);
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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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{
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return use(checks, tok, 3);
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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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{
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return use(checks, tok, 4);
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}
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/** declaring a variable */
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void declare(std::list<ExecutionPath *> &checks, const Token *vartok, const Token &tok, const bool p, const bool a) const
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{
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if (vartok->varId() == 0)
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return;
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// Suppress warnings if variable in inner scope has same name as variable in outer scope
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if (!tok.isStandardType())
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{
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std::set<unsigned int> dup;
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for (std::list<ExecutionPath *>::const_iterator it = checks.begin(); it != checks.end(); ++it)
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{
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UninitVar *c = dynamic_cast<UninitVar *>(*it);
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if (c && c->varname == vartok->str() && c->varId != vartok->varId())
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dup.insert(c->varId);
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}
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if (!dup.empty())
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{
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for (std::set<unsigned int>::const_iterator it = dup.begin(); it != dup.end(); ++it)
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bailOutVar(checks, *it);
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return;
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}
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}
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if (a || p || tok.isStandardType())
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checks.push_back(new UninitVar(owner, vartok->varId(), vartok->str(), p, a));
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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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{
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// check variable usages in rhs/index
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while (NULL != (tok2 = tok2->next()))
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{
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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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{
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// Multiple assignments..
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if (Token::Match(tok2->next(), ".|["))
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{
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const Token * tok3 = tok2;
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while (tok3)
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{
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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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{
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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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{
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// Variable declaration..
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if (Token::Match(tok.previous(), "[;{}] %var%") && tok.str() != "return")
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{
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if (Token::Match(&tok, "enum %type% {"))
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return tok.tokAt(2)->link();
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const Token * vartok = &tok;
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while (Token::Match(vartok, "const|struct"))
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vartok = vartok->next();
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if (Token::Match(vartok, "%type% *| %var% ;"))
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{
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vartok = vartok->next();
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const bool p(vartok->str() == "*");
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if (p)
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vartok = vartok->next();
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declare(checks, vartok, tok, p, false);
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return vartok;
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}
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// Variable declaration for array..
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if (Token::Match(vartok, "%type% %var% [") &&
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vartok->isStandardType() &&
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Token::simpleMatch(vartok->tokAt(2)->link(), "] ;"))
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{
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vartok = vartok->next();
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declare(checks, vartok, tok, false, true);
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return vartok->next()->link();
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}
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// Template pointer variable..
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if (Token::Match(vartok, "%type% ::|<"))
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{
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while (Token::Match(vartok, "%type% ::"))
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vartok = vartok->tokAt(2);
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if (Token::Match(vartok, "%type% < %type%"))
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{
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vartok = vartok->tokAt(3);
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while (vartok && (vartok->str() == "*" || vartok->isName()))
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vartok = vartok->next();
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if (Token::Match(vartok, "> * %var% ;"))
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{
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declare(checks, vartok->tokAt(2), tok, true, false);
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return vartok->tokAt(2);
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}
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}
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}
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}
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if (tok.str() == "return")
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{
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// is there assignment 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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{
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if (tok2->str() == "=" || tok2->str() == ">>")
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{
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assignment = true;
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break;
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}
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}
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|
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if (!assignment)
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{
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for (const Token *tok2 = tok.next(); tok2 && tok2->str() != ";"; tok2 = tok2->next())
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{
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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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|
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if (tok.varId())
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{
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// array variable passed as function parameter..
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if (Token::Match(tok.previous(), "[(,] %var% [+-,)]"))
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{
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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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{
|
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use(checks, &tok);
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return &tok;
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}
|
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|
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if (Token::Match(tok.previous(), "++|--") || Token::Match(tok.next(), "++|--"))
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{
|
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use(checks, &tok);
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return &tok;
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}
|
|
|
|
if (Token::Match(tok.previous(), "[;{}] %var% [=[.]"))
|
|
{
|
|
if (tok.next()->str() == ".")
|
|
{
|
|
if (use_dead_pointer(checks, &tok))
|
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{
|
|
return &tok;
|
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}
|
|
}
|
|
else
|
|
{
|
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const Token *tok2 = tok.next();
|
|
if (tok2->str() == "[" && Token::simpleMatch(tok2->link(), "] ="))
|
|
{
|
|
if (use_dead_pointer(checks, &tok))
|
|
{
|
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return &tok;
|
|
}
|
|
|
|
parserhs(tok2, checks);
|
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tok2 = tok2->link()->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.tokAt(3)->str() == "(")
|
|
return tok.tokAt(3);
|
|
}
|
|
|
|
else if (Token::simpleMatch(tok.previous(), ">>") || Token::simpleMatch(tok.next(), "="))
|
|
{
|
|
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% )"))
|
|
{
|
|
dealloc_pointer(checks, tok.tokAt(2));
|
|
return tok.tokAt(3);
|
|
}
|
|
|
|
// parse usage..
|
|
{
|
|
std::list<const Token *> var;
|
|
CheckNullPointer::parseFunctionCall(tok, var, 1);
|
|
for (std::list<const Token *>::const_iterator it = var.begin(); it != var.end(); ++it)
|
|
{
|
|
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(var.begin(), var.end(), *it) == var.end())
|
|
use_dead_pointer(checks, *it);
|
|
}
|
|
}
|
|
|
|
// strncpy doesn't 0-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();
|
|
}
|
|
}
|
|
|
|
if (Token::simpleMatch(&tok, "asm ( )"))
|
|
{
|
|
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% (") && CheckNullPointer::isUpper(tok2->str()))
|
|
{
|
|
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 (0 != (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() && !CheckNullPointer::isUpper(functionCall->str()) && 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->array || (c->pointer && 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% ) ("))
|
|
{
|
|
// is the variable passed as a parameter to some function?
|
|
unsigned int parlevel = 0;
|
|
for (const Token *tok2 = tok.link()->next(); tok2; tok2 = tok2->next())
|
|
{
|
|
if (tok2->str() == "(")
|
|
++parlevel;
|
|
|
|
else if (tok2->str() == ")")
|
|
{
|
|
if (parlevel <= 1)
|
|
break;
|
|
--parlevel;
|
|
}
|
|
|
|
else 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())
|
|
{
|
|
unsigned int indentlevel = 0;
|
|
for (const Token *tok3 = tok2->tokAt(5); tok3; tok3 = tok3->next())
|
|
{
|
|
if (tok3->str() == "{")
|
|
++indentlevel;
|
|
else if (tok3->str() == "}")
|
|
{
|
|
if (indentlevel == 0)
|
|
break;
|
|
--indentlevel;
|
|
}
|
|
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% ["))
|
|
use_array_or_pointer_data(checks, tok.str() == "!" ? tok.next() : &tok);
|
|
|
|
else if (Token::Match(&tok, "!| %var% ("))
|
|
{
|
|
std::list<const Token *> var;
|
|
CheckNullPointer::parseFunctionCall(tok.str() == "!" ? *tok.next() : tok, var, 1);
|
|
for (std::list<const Token *>::const_iterator it = var.begin(); it != var.end(); ++it)
|
|
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
|
|
unsigned int parlevel = 0;
|
|
for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next())
|
|
{
|
|
if (tok2->str() == "(")
|
|
++parlevel;
|
|
else if (tok2->str() == ")")
|
|
{
|
|
if (parlevel == 0)
|
|
break;
|
|
--parlevel;
|
|
}
|
|
else 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->tokAt(2)->link(), ") [{;]"))
|
|
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 (Token::Match(tok3->previous(), "++|--") ||
|
|
Token::Match(tok3->next(), "++|--"))
|
|
{
|
|
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 * const 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);
|
|
checkExecutionPaths(_tokenizer->tokens(), &c);
|
|
}
|
|
}
|
|
|
|
void CheckUninitVar::uninitstringError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::error, "uninitstring", "Dangerous usage of '" + varname + "' (strncpy doesn't always 0-terminate it)");
|
|
}
|
|
|
|
void CheckUninitVar::uninitdataError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::error, "uninitdata", "Data is allocated but not initialized: " + varname);
|
|
}
|
|
|
|
void CheckUninitVar::uninitvarError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::error, "uninitvar", "Uninitialized variable: " + varname);
|
|
}
|