This revision was automatically updated to reflect the committed changes.
Closed by commit rGefa8b6e884aa: [Analyzer][StreamChecker] Add check for
pointer escape. (authored by balazske).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D80699/new/
https://reviews.llvm.org/D80699
Files:
clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
clang/test/Analysis/stream.c
Index: clang/test/Analysis/stream.c
===================================================================
--- clang/test/Analysis/stream.c
+++ clang/test/Analysis/stream.c
@@ -192,4 +192,51 @@
rewind(f1); // expected-warning {{Stream might be invalid}}
fclose(f1);
}
-}
\ No newline at end of file
+}
+
+extern FILE *GlobalF;
+extern void takeFile(FILE *);
+
+void check_escape1() {
+ FILE *F = tmpfile();
+ if (!F)
+ return;
+ fwrite("1", 1, 1, F); // may fail
+ GlobalF = F;
+ fwrite("1", 1, 1, F); // no warning
+}
+
+void check_escape2() {
+ FILE *F = tmpfile();
+ if (!F)
+ return;
+ fwrite("1", 1, 1, F); // may fail
+ takeFile(F);
+ fwrite("1", 1, 1, F); // no warning
+}
+
+void check_escape3() {
+ FILE *F = tmpfile();
+ if (!F)
+ return;
+ takeFile(F);
+ F = freopen(0, "w", F);
+ if (!F)
+ return;
+ fwrite("1", 1, 1, F); // may fail
+ fwrite("1", 1, 1, F); // no warning
+}
+
+void check_escape4() {
+ FILE *F = tmpfile();
+ if (!F)
+ return;
+ fwrite("1", 1, 1, F); // may fail
+
+ // no escape at (non-StreamChecker-handled) system call
+ // FIXME: all such calls should be handled by the checker
+ fprintf(F, "0");
+
+ fwrite("1", 1, 1, F); // expected-warning {{might be 'indeterminate'}}
+ fclose(F);
+}
Index: clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -193,8 +193,8 @@
return State;
}
-class StreamChecker
- : public Checker<check::PreCall, eval::Call, check::DeadSymbols> {
+class StreamChecker : public Checker<check::PreCall, eval::Call,
+ check::DeadSymbols, check::PointerEscape> {
BuiltinBug BT_FileNull{this, "NULL stream pointer",
"Stream pointer might be NULL."};
BuiltinBug BT_UseAfterClose{
@@ -223,6 +223,10 @@
void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
bool evalCall(const CallEvent &Call, CheckerContext &C) const;
void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
+ ProgramStateRef checkPointerEscape(ProgramStateRef State,
+ const InvalidatedSymbols &Escaped,
+ const CallEvent *Call,
+ PointerEscapeKind Kind) const;
/// If true, evaluate special testing stream functions.
bool TestMode = false;
@@ -448,10 +452,14 @@
SymbolRef StreamSym = StreamVal->getAsSymbol();
// Do not care about concrete values for stream ("(FILE *)0x12345"?).
- // FIXME: Are stdin, stdout, stderr such values?
+ // FIXME: Can be stdin, stdout, stderr such values?
if (!StreamSym)
return;
+ // Do not handle untracked stream. It is probably escaped.
+ if (!State->get<StreamMap>(StreamSym))
+ return;
+
// Generate state for non-failed case.
// Return value is the passed stream pointer.
// According to the documentations, the stream is closed first
@@ -918,6 +926,28 @@
}
}
+ProgramStateRef StreamChecker::checkPointerEscape(
+ ProgramStateRef State, const InvalidatedSymbols &Escaped,
+ const CallEvent *Call, PointerEscapeKind Kind) const {
+ // Check for file-handling system call that is not handled by the checker.
+ // FIXME: The checker should be updated to handle all system calls that take
+ // 'FILE*' argument. These are now ignored.
+ if (Kind == PSK_DirectEscapeOnCall && Call->isInSystemHeader())
+ return State;
+
+ for (SymbolRef Sym : Escaped) {
+ // The symbol escaped.
+ // From now the stream can be manipulated in unknown way to the checker,
+ // it is not possible to handle it any more.
+ // Optimistically, assume that the corresponding file handle will be closed
+ // somewhere else.
+ // Remove symbol from state so the following stream calls on this symbol are
+ // not handled by the checker.
+ State = State->remove<StreamMap>(Sym);
+ }
+ return State;
+}
+
void ento::registerStreamChecker(CheckerManager &Mgr) {
Mgr.registerChecker<StreamChecker>();
}
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