llvm-project/clang/lib/Analysis/UndefinedAssignmentChecker.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

80 lines
2.3 KiB
C++

//===--- UndefinedAssignmentChecker.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 UndefinedAssginmentChecker, a builtin check in GRExprEngine that
// checks for assigning undefined values.
//
//===----------------------------------------------------------------------===//
#include "GRExprEngineInternalChecks.h"
#include "clang/Analysis/PathSensitive/CheckerVisitor.h"
#include "clang/Analysis/PathSensitive/BugReporter.h"
using namespace clang;
namespace {
class VISIBILITY_HIDDEN UndefinedAssignmentChecker
: public CheckerVisitor<UndefinedAssignmentChecker> {
BugType *BT;
public:
UndefinedAssignmentChecker() : BT(0) {}
static void *getTag();
virtual void PreVisitBind(CheckerContext &C, const Stmt *AssignE,
const Stmt *StoreE, SVal location,
SVal val);
};
}
void clang::RegisterUndefinedAssignmentChecker(GRExprEngine &Eng){
Eng.registerCheck(new UndefinedAssignmentChecker());
}
void *UndefinedAssignmentChecker::getTag() {
static int x = 0;
return &x;
}
void UndefinedAssignmentChecker::PreVisitBind(CheckerContext &C,
const Stmt *AssignE,
const Stmt *StoreE,
SVal location,
SVal val) {
if (!val.isUndef())
return;
ExplodedNode *N = C.GenerateSink();
if (!N)
return;
if (!BT)
BT = new BuiltinBug("Assigned value is garbage or undefined");
// Generate a report for this bug.
EnhancedBugReport *R = new EnhancedBugReport(*BT, BT->getName(), N);
if (AssignE) {
const Expr *ex = 0;
if (const BinaryOperator *B = dyn_cast<BinaryOperator>(AssignE))
ex = B->getRHS();
else if (const DeclStmt *DS = dyn_cast<DeclStmt>(AssignE)) {
const VarDecl* VD = dyn_cast<VarDecl>(DS->getSingleDecl());
ex = VD->getInit();
}
if (ex) {
R->addRange(ex->getSourceRange());
R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, ex);
}
}
C.EmitReport(R);
}