Szelethus marked an inline comment as done. Szelethus added a comment. In D82598#2162496 <https://reviews.llvm.org/D82598#2162496>, @xazax.hun wrote:
> In D82598#2162239 <https://reviews.llvm.org/D82598#2162239>, @Szelethus wrote: > > > I chased my own tail for weeks before realizing that there is indeed > > another instance when a live **statement** is stored, other then > > `ObjCForCollectionStmt`... > > > > void clang_analyzer_eval(bool); > > > > void test_lambda_refcapture() { > > int a = 6; > > [&](int &a) { a = 42; }(a); > > clang_analyzer_eval(a == 42); // expected-warning{{TRUE}} > > } > > > > > Hmm, interesting. I don't really understand why do we need to keep that block > live, as we definitely won't use any of the value it provides (since it does > not provide a value at all). Actually, what I said initially is true: > [...] the only non-expression statements it **queried** are > ObjCForCollectionStmts [...] so I think it'd be okay to simply drop this. Also, its easy to see why this popped up, because... (cont. in inline) ================ Comment at: clang/lib/Analysis/LiveVariables.cpp:317-320 for (Stmt *Child : S->children()) { - if (Child) - AddLiveStmt(val.liveStmts, LV.SSetFact, Child); + if (const auto *E = dyn_cast_or_null<Expr>(Child)) + AddLiveExpr(val.liveExprs, LV.SSetFact, E); } ---------------- ..this part of the code caused the issue. Looking at the related CFG, ```lang=c++ void test_lambda_refcapture() [B2 (ENTRY)] Succs (1): B1 [B1] 1: 6 2: int a = 6; 3: operator() 4: [B1.3] (ImplicitCastExpr, FunctionToPointerDecay, void (*)(int &) const) 5: [&](int &a) { a = 42; } 6: [B1.5] 7: [B1.6] (ImplicitCastExpr, NoOp, const class (lambda at /home/szelethus/Documents/llvm-project/clang/test/Analysis/live-stmts.cpp:183:3)) 8: a 9: [B1.7]([B1.8]) (OperatorCall) 10: clang_analyzer_eval 11: [B1.10] (ImplicitCastExpr, FunctionToPointerDecay, void (*)(_Bool)) 12: a 13: [B1.12] (ImplicitCastExpr, LValueToRValue, int) 14: 42 15: [B1.13] == [B1.14] 16: [B1.11]([B1.15]) Preds (1): B2 Succs (1): B0 [B0 (EXIT)] Preds (1): B1 ``` its clear that element 5 added the live statement, and I think that that this entire CFG just simply isn't right. Shouldn't we have a distinct element for the assignment? Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D82598/new/ https://reviews.llvm.org/D82598 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
