cppcheck/lib/check64bit.cpp

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/*
* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2015 Daniel Marjamäki and Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
//---------------------------------------------------------------------------
// 64-bit portability
//---------------------------------------------------------------------------
#include "check64bit.h"
#include "symboldatabase.h"
//---------------------------------------------------------------------------
// Register this check class (by creating a static instance of it)
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namespace {
Check64BitPortability instance;
}
/** Is given variable a pointer or array? */
static bool isaddr(const Variable *var)
{
return (var && (var->isPointer() || var->isArray()));
}
/** Is given variable an integer variable */
static bool isint(const Variable *var)
{
return (var && var->isIntegralType() && !var->isArrayOrPointer() && var->typeStartToken()->str() != "bool");
}
void Check64BitPortability::pointerassignment()
{
if (!_settings->isEnabled("portability"))
return;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
// Check return values
const std::size_t functions = symbolDatabase->functionScopes.size();
for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symbolDatabase->functionScopes[i];
if (scope->function == 0 || !scope->function->hasBody) // We only look for functions with a body
continue;
bool retPointer = false;
if (scope->function->token->strAt(-1) == "*") // Function returns a pointer
retPointer = true;
else if (Token::Match(scope->function->token->previous(), "int|long|DWORD")) // Function returns an integer
;
else
continue;
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
if (Token::Match(tok, "return %var%|%num% [;+]") && !Token::simpleMatch(tok, "return 0 ;")) {
enum { NO, INT, PTR, PTRDIFF } type = NO;
for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next()) {
if ((type == NO || type == INT) && Token::Match(tok2, "%var% [+;]") && isaddr(tok2->variable()))
type = PTR;
else if (type == NO && (tok2->isNumber() || isint(tok2->variable())))
type = INT;
else if (type == PTR && Token::Match(tok2, "- %var%") && isaddr(tok2->next()->variable()))
type = PTRDIFF;
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else if (tok2->str() == "(") {
// TODO: handle parentheses
type = NO;
break;
} else if (type == PTR && Token::simpleMatch(tok2, "."))
type = NO; // Reset after pointer reference, see #4642
else if (tok2->str() == ";")
break;
}
if (retPointer && (type == INT || type == PTRDIFF))
returnIntegerError(tok);
else if (!retPointer && type == PTR)
returnPointerError(tok);
}
}
}
// Check assignments
for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symbolDatabase->functionScopes[i];
for (const Token *tok = scope->classStart; tok && tok != scope->classEnd; tok = tok->next()) {
if (Token::Match(tok, "[;{}] %var% = %var%")) {
const Token* tok2 = tok->tokAt(3);
while (Token::Match(tok2->next(), ".|::"))
tok2 = tok2->tokAt(2);
if (!Token::Match(tok2, "%var% ;|+"))
continue;
const Variable *var1(tok->next()->variable());
const Variable *var2(tok2->variable());
if (isaddr(var1) && isint(var2) && tok2->strAt(1) != "+")
assignmentIntegerToAddressError(tok->next());
else if (isint(var1) && isaddr(var2) && !tok2->isPointerCompare()) {
// assigning address => warning
// some trivial addition => warning
if (Token::Match(tok2->next(), "+ %any% !!;"))
continue;
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assignmentAddressToIntegerError(tok->next());
}
}
}
}
}
void Check64BitPortability::assignmentAddressToIntegerError(const Token *tok)
{
reportError(tok, Severity::portability,
"AssignmentAddressToInteger",
"Assigning a pointer to an integer is not portable.\n"
"Assigning a pointer to an integer (int/long/etc) is not portable across different platforms and "
"compilers. For example in 32-bit Windows and linux they are same width, but in 64-bit Windows and linux "
"they are of different width. In worst case you end up assigning 64-bit address to 32-bit integer. The safe "
"way is to store addresses only in pointer types (or typedefs like uintptr_t).");
}
void Check64BitPortability::assignmentIntegerToAddressError(const Token *tok)
{
reportError(tok, Severity::portability,
"AssignmentIntegerToAddress",
"Assigning an integer to a pointer is not portable.\n"
"Assigning an integer (int/long/etc) to a pointer is not portable across different platforms and "
"compilers. For example in 32-bit Windows and linux they are same width, but in 64-bit Windows and linux "
"they are of different width. In worst case you end up assigning 64-bit integer to 32-bit pointer. The safe "
"way is to store addresses only in pointer types (or typedefs like uintptr_t).");
}
void Check64BitPortability::returnPointerError(const Token *tok)
{
reportError(tok, Severity::portability,
"CastAddressToIntegerAtReturn",
"Returning an address value in a function with integer return type is not portable.\n"
"Returning an address value in a function with integer (int/long/etc) return type is not portable across "
"different platforms and compilers. For example in 32-bit Windows and Linux they are same width, but in "
"64-bit Windows and Linux they are of different width. In worst case you end up casting 64-bit address down "
"to 32-bit integer. The safe way is to always return an integer.");
}
void Check64BitPortability::returnIntegerError(const Token *tok)
{
reportError(tok, Severity::portability,
"CastIntegerToAddressAtReturn",
"Returning an integer in a function with pointer return type is not portable.\n"
"Returning an integer (int/long/etc) in a function with pointer return type is not portable across different "
"platforms and compilers. For example in 32-bit Windows and Linux they are same width, but in 64-bit Windows "
"and Linux they are of different width. In worst case you end up casting 64-bit integer down to 32-bit pointer. "
"The safe way is to always return a pointer.");
}