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UndefBranchChecker: more bug reporter helper information emit. 

llvm-svn: 89643
This commit is contained in:
Zhongxing Xu 2009-11-23 03:29:59 +00:00
parent 39dbfd3c58
commit 5f76620b53
2 changed files with 54 additions and 90 deletions
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90
clang/lib/Analysis/GRExprEngineInternalChecks.cpp
View File

@ -204,96 +204,6 @@ public:
}
};
class VISIBILITY_HIDDEN ArgReport : public BuiltinBugReport {
const Stmt *Arg;
public:
ArgReport(BugType& bt, const char* desc, ExplodedNode *n,
const Stmt *arg)
: BuiltinBugReport(bt, desc, n), Arg(arg) {}
ArgReport(BugType& bt, const char *shortDesc, const char *desc,
ExplodedNode *n, const Stmt *arg)
: BuiltinBugReport(bt, shortDesc, desc, n), Arg(arg) {}
const Stmt *getArg() const { return Arg; }
};
class VISIBILITY_HIDDEN UndefBranch : public BuiltinBug {
struct VISIBILITY_HIDDEN FindUndefExpr {
GRStateManager& VM;
const GRState* St;
FindUndefExpr(GRStateManager& V, const GRState* S) : VM(V), St(S) {}
Expr* FindExpr(Expr* Ex) {
if (!MatchesCriteria(Ex))
return 0;
for (Stmt::child_iterator I=Ex->child_begin(), E=Ex->child_end();I!=E;++I)
if (Expr* ExI = dyn_cast_or_null<Expr>(*I)) {
Expr* E2 = FindExpr(ExI);
if (E2) return E2;
}
return Ex;
}
bool MatchesCriteria(Expr* Ex) { return St->getSVal(Ex).isUndef(); }
};
public:
UndefBranch(GRExprEngine *eng)
: BuiltinBug(eng,"Use of garbage value",
"Branch condition evaluates to an undefined or garbage value")
{}
void FlushReportsImpl(BugReporter& BR, GRExprEngine& Eng) {
for (GRExprEngine::undef_branch_iterator I=Eng.undef_branches_begin(),
E=Eng.undef_branches_end(); I!=E; ++I) {
// What's going on here: we want to highlight the subexpression of the
// condition that is the most likely source of the "uninitialized
// branch condition." We do a recursive walk of the condition's
// subexpressions and roughly look for the most nested subexpression
// that binds to Undefined. We then highlight that expression's range.
BlockEdge B = cast<BlockEdge>((*I)->getLocation());
Expr* Ex = cast<Expr>(B.getSrc()->getTerminatorCondition());
assert (Ex && "Block must have a terminator.");
// Get the predecessor node and check if is a PostStmt with the Stmt
// being the terminator condition. We want to inspect the state
// of that node instead because it will contain main information about
// the subexpressions.
assert (!(*I)->pred_empty());
// Note: any predecessor will do. They should have identical state,
// since all the BlockEdge did was act as an error sink since the value
// had to already be undefined.
ExplodedNode *N = *(*I)->pred_begin();
ProgramPoint P = N->getLocation();
const GRState* St = (*I)->getState();
if (PostStmt* PS = dyn_cast<PostStmt>(&P))
if (PS->getStmt() == Ex)
St = N->getState();
FindUndefExpr FindIt(Eng.getStateManager(), St);
Ex = FindIt.FindExpr(Ex);
ArgReport *R = new ArgReport(*this, desc.c_str(), *I, Ex);
R->addRange(Ex->getSourceRange());
BR.EmitReport(R);
}
}
void registerInitialVisitors(BugReporterContext& BRC,
const ExplodedNode* N,
BuiltinBugReport *R) {
registerTrackNullOrUndefValue(BRC, static_cast<ArgReport*>(R)->getArg(),
N);
}
};
} // end clang namespace
//===----------------------------------------------------------------------===//

54
clang/lib/Analysis/UndefBranchChecker.cpp
View File

@ -21,6 +21,29 @@ namespace {
class VISIBILITY_HIDDEN UndefBranchChecker : public Checker {
BuiltinBug *BT;
struct VISIBILITY_HIDDEN FindUndefExpr {
GRStateManager& VM;
const GRState* St;
FindUndefExpr(GRStateManager& V, const GRState* S) : VM(V), St(S) {}
Expr* FindExpr(Expr* Ex) {
if (!MatchesCriteria(Ex))
return 0;
for (Stmt::child_iterator I=Ex->child_begin(), E=Ex->child_end();I!=E;++I)
if (Expr* ExI = dyn_cast_or_null<Expr>(*I)) {
Expr* E2 = FindExpr(ExI);
if (E2) return E2;
}
return Ex;
}
bool MatchesCriteria(Expr* Ex) { return St->getSVal(Ex).isUndef(); }
};
public:
UndefBranchChecker() : BT(0) {}
static void *getTag();
@ -54,6 +77,37 @@ void UndefBranchChecker::VisitBranchCondition(GRBranchNodeBuilder &Builder,
EnhancedBugReport *R = new EnhancedBugReport(*BT, BT->getDescription(),N);
R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue,
Condition);
// What's going on here: we want to highlight the subexpression of the
// condition that is the most likely source of the "uninitialized
// branch condition." We do a recursive walk of the condition's
// subexpressions and roughly look for the most nested subexpression
// that binds to Undefined. We then highlight that expression's range.
BlockEdge B = cast<BlockEdge>(N->getLocation());
Expr* Ex = cast<Expr>(B.getSrc()->getTerminatorCondition());
assert (Ex && "Block must have a terminator.");
// Get the predecessor node and check if is a PostStmt with the Stmt
// being the terminator condition. We want to inspect the state
// of that node instead because it will contain main information about
// the subexpressions.
assert (!N->pred_empty());
// Note: any predecessor will do. They should have identical state,
// since all the BlockEdge did was act as an error sink since the value
// had to already be undefined.
ExplodedNode *PrevN = *N->pred_begin();
ProgramPoint P = PrevN->getLocation();
const GRState* St = N->getState();
if (PostStmt* PS = dyn_cast<PostStmt>(&P))
if (PS->getStmt() == Ex)
St = PrevN->getState();
FindUndefExpr FindIt(Eng.getStateManager(), St);
Ex = FindIt.FindExpr(Ex);
R->addRange(Ex->getSourceRange());
Eng.getBugReporter().EmitReport(R);
}