llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-static-analyzer-1 Author: Balazs Benics (steakhal) <details> <summary>Changes</summary> Patch by Arseniy Zaostrovnykh! --- Full diff: https://github.com/llvm/llvm-project/pull/109112.diff 2 Files Affected: - (modified) clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp (+45-4) - (modified) clang/test/Analysis/stream-note.c (+9) ``````````diff diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp index 8bb7880a3cc283..c0f3591662b418 100644 --- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp @@ -1835,6 +1835,46 @@ StreamChecker::ensureStreamNonNull(SVal StreamVal, const Expr *StreamE, return StateNotNull; } +namespace { +class StreamClosedVisitor final : public BugReporterVisitor { + const SymbolRef StreamSym; + bool Satisfied = false; + +public: + explicit StreamClosedVisitor(SymbolRef StreamSym) : StreamSym(StreamSym) {} + + static void *getTag() { + static int Tag = 0; + return &Tag; + } + + void Profile(llvm::FoldingSetNodeID &ID) const override { + ID.AddPointer(getTag()); + ID.AddPointer(StreamSym); + } + + PathDiagnosticPieceRef VisitNode(const ExplodedNode *N, + BugReporterContext &BRC, + PathSensitiveBugReport &BR) override { + if (Satisfied) + return nullptr; + const StreamState *PredSS = + N->getFirstPred()->getState()->get<StreamMap>(StreamSym); + if (PredSS && PredSS->isClosed()) + return nullptr; + + const Stmt *S = N->getStmtForDiagnostics(); + if (!S) + return nullptr; + Satisfied = true; + PathDiagnosticLocation Pos(S, BRC.getSourceManager(), + N->getLocationContext()); + llvm::StringLiteral Msg = "Stream is closed here"; + return std::make_shared<PathDiagnosticEventPiece>(Pos, Msg); + } +}; +} // namespace + ProgramStateRef StreamChecker::ensureStreamOpened(SVal StreamVal, CheckerContext &C, ProgramStateRef State) const { @@ -1849,11 +1889,12 @@ ProgramStateRef StreamChecker::ensureStreamOpened(SVal StreamVal, if (SS->isClosed()) { // Using a stream pointer after 'fclose' causes undefined behavior // according to cppreference.com . - ExplodedNode *N = C.generateErrorNode(); - if (N) { - C.emitReport(std::make_unique<PathSensitiveBugReport>( + if (ExplodedNode *N = C.generateErrorNode()) { + auto R = std::make_unique<PathSensitiveBugReport>( BT_UseAfterClose, - "Stream might be already closed. Causes undefined behaviour.", N)); + "Stream might be already closed. Causes undefined behaviour.", N); + R->addVisitor<StreamClosedVisitor>(Sym); + C.emitReport(std::move(R)); return nullptr; } diff --git a/clang/test/Analysis/stream-note.c b/clang/test/Analysis/stream-note.c index 3aef707d50056e..02251e2e12d6a1 100644 --- a/clang/test/Analysis/stream-note.c +++ b/clang/test/Analysis/stream-note.c @@ -264,3 +264,12 @@ void error_fseek_read_eof(void) { fgetc(F); // no warning fclose(F); } + +void check_note_at_use_after_close(void) { + FILE *F = tmpfile(); + if (!F) // expected-note {{'F' is non-null}} expected-note {{Taking false branch}} + return; + fclose(F); // expected-note {{Stream is closed here}} + rewind(F); // expected-warning {{Stream might be already closed. Causes undefined behaviour}} + // expected-note@-1 {{Stream might be already closed. Causes undefined behaviour}} +} `````````` </details> https://github.com/llvm/llvm-project/pull/109112 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
