blob: 1cb8a8de7348d1332705799bdf0b805b1057a20c (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
//=== CastSizeChecker.cpp ---------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// CastSizeChecker checks when casting a malloc'ed symbolic region to type T,
// whether the size of the symbolic region is a multiple of the size of T.
//
//===----------------------------------------------------------------------===//
#include "ClangSACheckers.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/AST/CharUnits.h"
using namespace clang;
using namespace ento;
namespace {
class CastSizeChecker : public Checker< check::PreStmt<CastExpr> > {
mutable OwningPtr<BuiltinBug> BT;
public:
void checkPreStmt(const CastExpr *CE, CheckerContext &C) const;
};
}
void CastSizeChecker::checkPreStmt(const CastExpr *CE,CheckerContext &C) const {
const Expr *E = CE->getSubExpr();
ASTContext &Ctx = C.getASTContext();
QualType ToTy = Ctx.getCanonicalType(CE->getType());
const PointerType *ToPTy = dyn_cast<PointerType>(ToTy.getTypePtr());
if (!ToPTy)
return;
QualType ToPointeeTy = ToPTy->getPointeeType();
// Only perform the check if 'ToPointeeTy' is a complete type.
if (ToPointeeTy->isIncompleteType())
return;
ProgramStateRef state = C.getState();
const MemRegion *R = state->getSVal(E, C.getLocationContext()).getAsRegion();
if (R == 0)
return;
const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R);
if (SR == 0)
return;
SValBuilder &svalBuilder = C.getSValBuilder();
SVal extent = SR->getExtent(svalBuilder);
const llvm::APSInt *extentInt = svalBuilder.getKnownValue(state, extent);
if (!extentInt)
return;
CharUnits regionSize = CharUnits::fromQuantity(extentInt->getSExtValue());
CharUnits typeSize = C.getASTContext().getTypeSizeInChars(ToPointeeTy);
// Ignore void, and a few other un-sizeable types.
if (typeSize.isZero())
return;
if (regionSize % typeSize != 0) {
if (ExplodedNode *errorNode = C.generateSink()) {
if (!BT)
BT.reset(new BuiltinBug("Cast region with wrong size.",
"Cast a region whose size is not a multiple of the"
" destination type size."));
BugReport *R = new BugReport(*BT, BT->getDescription(),
errorNode);
R->addRange(CE->getSourceRange());
C.emitReport(R);
}
}
}
void ento::registerCastSizeChecker(CheckerManager &mgr) {
mgr.registerChecker<CastSizeChecker>();
}
|
