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[analyzer] Avoid crashes in the stream checker #100901

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[analyzer] Avoid crashes in the stream checker #100901

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20 changes: 12 additions & 8 deletions clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -946,14 +946,18 @@ void StreamChecker::evalFopen(const FnDescription *Desc, const CallEvent &Call,
std::tie(StateNotNull, StateNull) =
C.getConstraintManager().assumeDual(State, RetVal);

StateNotNull =
StateNotNull->set<StreamMap>(RetSym, StreamState::getOpened(Desc));
StateNull =
StateNull->set<StreamMap>(RetSym, StreamState::getOpenFailed(Desc));

C.addTransition(StateNotNull,
constructLeakNoteTag(C, RetSym, "Stream opened here"));
C.addTransition(StateNull);
if (StateNotNull)
StateNotNull =
StateNotNull->set<StreamMap>(RetSym, StreamState::getOpened(Desc));
if (StateNull)
StateNull =
StateNull->set<StreamMap>(RetSym, StreamState::getOpenFailed(Desc));

if (StateNotNull)
C.addTransition(StateNotNull,
constructLeakNoteTag(C, RetSym, "Stream opened here"));
if (StateNull)
C.addTransition(StateNull);
}

void StreamChecker::preFreopen(const FnDescription *Desc, const CallEvent &Call,
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25 changes: 25 additions & 0 deletions clang/test/Analysis/stream-no-crash.c
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Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
// RUN: %clang_analyze_cc1 -analyzer-checker=core,unix.Stream -verify %s

// This test is isolate since it uses line markers to repro the problem.
// The test is expected to find the issues noted below without crashing.

# 1 "" 1
# 1 "" 1
# 1 "" 1
# 1 "" 1 3
typedef FILE;
extern *stdout;
char a;
*fopen();
# 0 "" 2
# 7 "" 2
# 7 "" 2
# 7 "" 2
void b() {
fopen(&a, "");
int c = stdout && c;
b();
}
// expected-warning@-3{{Assigned value is garbage or undefined}}
// expected-warning@-4{{Opened stream never closed. Potential resource leak}}