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[analyzer] SimpleStreamChecker - remove evalAssume and other refinements 

llvm-svn: 167099
This commit is contained in:
Anna Zaks 2012-10-31 02:32:41 +00:00
parent ebc56b217b
commit 1e80d8b49c
2 changed files with 37 additions and 56 deletions
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86
clang/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp
View File

@ -27,10 +27,11 @@ namespace {
typedef llvm::SmallVector<SymbolRef, 2> SymbolVector;
struct StreamState {
private:
enum Kind { Opened, Closed } K;
StreamState(Kind InK) : K(InK) { }
public:
bool isOpened() const { return K == Opened; }
bool isClosed() const { return K == Closed; }
@ -47,8 +48,7 @@ struct StreamState {
class SimpleStreamChecker: public Checker<check::PostStmt<CallExpr>,
check::PreStmt<CallExpr>,
check::DeadSymbols,
eval::Assume > {
check::DeadSymbols > {
mutable IdentifierInfo *IIfopen, *IIfclose;
@ -61,11 +61,12 @@ class SimpleStreamChecker: public Checker<check::PostStmt<CallExpr>,
const CallExpr *Call,
CheckerContext &C) const;
ExplodedNode *reportLeaks(SymbolVector LeakedStreams,
CheckerContext &C) const;
void reportLeaks(SymbolVector LeakedStreams,
CheckerContext &C,
ExplodedNode *ErrNode) const;
public:
SimpleStreamChecker() : IIfopen(0), IIfclose(0) {}
SimpleStreamChecker();
/// Process fopen.
void checkPostStmt(const CallExpr *Call, CheckerContext &C) const;
@ -73,9 +74,6 @@ public:
void checkPreStmt(const CallExpr *Call, CheckerContext &C) const;
void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond,
bool Assumption) const;
};
} // end anonymous namespace
@ -84,6 +82,17 @@ public:
/// state. Let's store it in the ProgramState.
REGISTER_MAP_WITH_PROGRAMSTATE(StreamMap, SymbolRef, StreamState)
SimpleStreamChecker::SimpleStreamChecker() : IIfopen(0), IIfclose(0) {
// Initialize the bug types.
DoubleCloseBugType.reset(new BugType("Double fclose",
"Unix Stream API Error"));
LeakBugType.reset(new BugType("Resource Leak",
"Unix Stream API Error"));
// Sinks are higher importance bugs as well as calls to assert() or exit(0).
LeakBugType->setSuppressOnSink(true);
}
void SimpleStreamChecker::checkPostStmt(const CallExpr *Call,
CheckerContext &C) const {
initIdentifierInfo(C.getASTContext());
@ -135,32 +144,20 @@ void SimpleStreamChecker::checkDeadSymbols(SymbolReaper &SymReaper,
SymbolRef Sym = I->first;
if (SymReaper.isDead(Sym)) {
const StreamState &SS = I->second;
if (SS.isOpened())
LeakedStreams.push_back(Sym);
if (SS.isOpened()) {
// If a symbolic region is NULL, assume that allocation failed on
// this path and do not report a leak.
if (!State->getConstraintManager().isNull(State, Sym).isTrue())
LeakedStreams.push_back(Sym);
}
// Remove the dead symbol from the streams map.
State = State->remove<StreamMap>(Sym);
}
}
ExplodedNode *N = reportLeaks(LeakedStreams, C);
C.addTransition(State, N);
}
// If a symbolic region is assumed to NULL (or another constant), stop tracking
// it - assuming that allocation failed on this path.
ProgramStateRef SimpleStreamChecker::evalAssume(ProgramStateRef State,
SVal Cond,
bool Assumption) const {
StreamMapTy TrackedStreams = State->get<StreamMap>();
SymbolVector LeakedStreams;
for (StreamMapTy::iterator I = TrackedStreams.begin(),
E = TrackedStreams.end(); I != E; ++I) {
SymbolRef Sym = I->first;
if (State->getConstraintManager().isNull(State, Sym).isTrue())
State = State->remove<StreamMap>(Sym);
}
return State;
ExplodedNode *N = C.addTransition(State);
reportLeaks(LeakedStreams, C, N);
}
void SimpleStreamChecker::reportDoubleClose(SymbolRef FileDescSym,
@ -168,14 +165,10 @@ void SimpleStreamChecker::reportDoubleClose(SymbolRef FileDescSym,
CheckerContext &C) const {
// We reached a bug, stop exploring the path here by generating a sink.
ExplodedNode *ErrNode = C.generateSink();
// If this error node already exists, return.
// If we've already reached this node on another path, return.
if (!ErrNode)
return;
// Initialize the bug type.
if (!DoubleCloseBugType)
DoubleCloseBugType.reset(new BugType("Double fclose",
"Unix Stream API Error"));
// Generate the report.
BugReport *R = new BugReport(*DoubleCloseBugType,
"Closing a previously closed file stream", ErrNode);
@ -184,26 +177,9 @@ void SimpleStreamChecker::reportDoubleClose(SymbolRef FileDescSym,
C.EmitReport(R);
}
ExplodedNode *SimpleStreamChecker::reportLeaks(SymbolVector LeakedStreams,
CheckerContext &C) const {
ExplodedNode *Pred = C.getPredecessor();
if (LeakedStreams.empty())
return Pred;
// Generate an intermediate node representing the leak point.
static SimpleProgramPointTag Tag("StreamChecker : Leak");
ExplodedNode *ErrNode = C.addTransition(Pred->getState(), Pred, &Tag);
if (!ErrNode)
return Pred;
// Initialize the bug type.
if (!LeakBugType) {
LeakBugType.reset(new BuiltinBug("Resource Leak",
"Unix Stream API Error"));
// Sinks are higher importance bugs as well as calls to assert() or exit(0).
LeakBugType->setSuppressOnSink(true);
}
void SimpleStreamChecker::reportLeaks(SymbolVector LeakedStreams,
CheckerContext &C,
ExplodedNode *ErrNode) const {
// Attach bug reports to the leak node.
// TODO: Identify the leaked file descriptor.
for (llvm::SmallVector<SymbolRef, 2>::iterator
@ -213,8 +189,6 @@ ExplodedNode *SimpleStreamChecker::reportLeaks(SymbolVector LeakedStreams,
R->markInteresting(*I);
C.EmitReport(R);
}
return ErrNode;
}
void SimpleStreamChecker::initIdentifierInfo(ASTContext &Ctx) const {

7
clang/test/Analysis/simple-stream-checks.c
View File

@ -42,3 +42,10 @@ void checkLeakFollowedByAssert(int *Data) {
fclose(F);
}
}
void CloseOnlyOnValidFileHandle() {
FILE *F = fopen("myfile.txt", "w");
if (F)
fclose(F);
int x = 0; // no warning
}