forked from OSchip/llvm-project
97 lines
3.2 KiB
C++
97 lines
3.2 KiB
C++
//==- CheckSizeofPointer.cpp - Check for sizeof on pointers ------*- C++ -*-==//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines a check for unintended use of sizeof() on pointer
|
|
// expressions.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
|
|
#include "clang/AST/StmtVisitor.h"
|
|
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
|
|
#include "clang/StaticAnalyzer/Core/Checker.h"
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
|
|
|
|
using namespace clang;
|
|
using namespace ento;
|
|
|
|
namespace {
|
|
class WalkAST : public StmtVisitor<WalkAST> {
|
|
BugReporter &BR;
|
|
const CheckerBase *Checker;
|
|
AnalysisDeclContext* AC;
|
|
|
|
public:
|
|
WalkAST(BugReporter &br, const CheckerBase *checker, AnalysisDeclContext *ac)
|
|
: BR(br), Checker(checker), AC(ac) {}
|
|
void VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E);
|
|
void VisitStmt(Stmt *S) { VisitChildren(S); }
|
|
void VisitChildren(Stmt *S);
|
|
};
|
|
}
|
|
|
|
void WalkAST::VisitChildren(Stmt *S) {
|
|
for (Stmt *Child : S->children())
|
|
if (Child)
|
|
Visit(Child);
|
|
}
|
|
|
|
// CWE-467: Use of sizeof() on a Pointer Type
|
|
void WalkAST::VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E) {
|
|
if (E->getKind() != UETT_SizeOf)
|
|
return;
|
|
|
|
// If an explicit type is used in the code, usually the coder knows what they are
|
|
// doing.
|
|
if (E->isArgumentType())
|
|
return;
|
|
|
|
QualType T = E->getTypeOfArgument();
|
|
if (T->isPointerType()) {
|
|
|
|
// Many false positives have the form 'sizeof *p'. This is reasonable
|
|
// because people know what they are doing when they intentionally
|
|
// dereference the pointer.
|
|
Expr *ArgEx = E->getArgumentExpr();
|
|
if (!isa<DeclRefExpr>(ArgEx->IgnoreParens()))
|
|
return;
|
|
|
|
PathDiagnosticLocation ELoc =
|
|
PathDiagnosticLocation::createBegin(E, BR.getSourceManager(), AC);
|
|
BR.EmitBasicReport(AC->getDecl(), Checker,
|
|
"Potential unintended use of sizeof() on pointer type",
|
|
categories::LogicError,
|
|
"The code calls sizeof() on a pointer type. "
|
|
"This can produce an unexpected result.",
|
|
ELoc, ArgEx->getSourceRange());
|
|
}
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// SizeofPointerChecker
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
class SizeofPointerChecker : public Checker<check::ASTCodeBody> {
|
|
public:
|
|
void checkASTCodeBody(const Decl *D, AnalysisManager& mgr,
|
|
BugReporter &BR) const {
|
|
WalkAST walker(BR, this, mgr.getAnalysisDeclContext(D));
|
|
walker.Visit(D->getBody());
|
|
}
|
|
};
|
|
}
|
|
|
|
void ento::registerSizeofPointerChecker(CheckerManager &mgr) {
|
|
mgr.registerChecker<SizeofPointerChecker>();
|
|
}
|
|
|
|
bool ento::shouldRegisterSizeofPointerChecker(const CheckerManager &mgr) {
|
|
return true;
|
|
}
|