llvm-project/clang/lib/Analysis/UndefinedArraySubscriptChecker.cpp
Ted Kremenek f57351570e Clean up the Checker API a little more, resolving some hidden bugs
along the way.  Important changes:

1) To generate a sink node, use GenerateSink(); GenerateNode() is for
generating regular transitions.  This makes the API clearer and also
allows us to use the 'bool' option to GenerateNode() for a different
purpose.

2) GenerateNode() now automatically adds the generated node to the
destination ExplodedNodeSet (autotransition) unless the client
specifies otherwise with a bool flag.  Several checkers did not call
'addTransition()' after calling 'GenerateNode()', causing the
simulation path to be prematurely culled when a non-fail stop bug was
encountered.

3) Add variants of GenerateNode()/GenerateSink() that take neither a
Stmt* or a GRState*; most callers of GenerateNode() just pass in the
same Stmt* as provided when the CheckerContext object is created; we
can just use that the majority of the time.  This cleanup also allows
us to potentially coelesce the APIs for evaluating branches and
end-of-paths (which currently directly use builders).

4) addTransition() no longer needs to be called except for a few
cases.  We now have a variant of addTransition() that takes a
GRState*; this allows one to propagate the updated state without
caring about generating a new node explicitly.  This nicely cleaned up
a bunch of cases that called autoTransition() with a bunch of
conditional logic surround the call (that common logic has now been
swallowed up by addTransition() itself).

llvm-svn: 89707
2009-11-23 22:22:01 +00:00

57 lines
1.9 KiB
C++

//===--- UndefinedArraySubscriptChecker.h ----------------------*- C++ -*--===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This defines UndefinedArraySubscriptChecker, a builtin check in GRExprEngine
// that performs checks for undefined array subscripts.
//
//===----------------------------------------------------------------------===//
#include "clang/Analysis/PathSensitive/CheckerVisitor.h"
#include "clang/Analysis/PathSensitive/BugReporter.h"
#include "GRExprEngineInternalChecks.h"
using namespace clang;
namespace {
class VISIBILITY_HIDDEN UndefinedArraySubscriptChecker
: public CheckerVisitor<UndefinedArraySubscriptChecker> {
BugType *BT;
public:
UndefinedArraySubscriptChecker() : BT(0) {}
static void *getTag() {
static int x = 0;
return &x;
}
void PreVisitArraySubscriptExpr(CheckerContext &C,
const ArraySubscriptExpr *A);
};
} // end anonymous namespace
void clang::RegisterUndefinedArraySubscriptChecker(GRExprEngine &Eng) {
Eng.registerCheck(new UndefinedArraySubscriptChecker());
}
void
UndefinedArraySubscriptChecker::PreVisitArraySubscriptExpr(CheckerContext &C,
const ArraySubscriptExpr *A) {
if (C.getState()->getSVal(A->getIdx()).isUndef()) {
if (ExplodedNode *N = C.GenerateSink()) {
if (!BT)
BT = new BuiltinBug("Array subscript is undefined");
// Generate a report for this bug.
EnhancedBugReport *R = new EnhancedBugReport(*BT, BT->getName(), N);
R->addRange(A->getIdx()->getSourceRange());
R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue,
A->getIdx());
C.EmitReport(R);
}
}
}