ahatanak added inline comments.
================ Comment at: lib/CodeGen/CGDecl.cpp:917 + if (!InsertPt) + Builder.SetInsertPoint(BB, BB->begin()); + // If InsertPt is a terminator, insert it before InsertPt. ---------------- rjmccall wrote: > BB->begin() is not necessarily a legal place to insert a call. This could > happen if e.g. a scope was unconditionally entered after a statement > including a ternary expression. > > Also, I think lexical scopes don't necessarily have an active basic block > upon entry, because their entry can be unreachable. This happens most > importantly with e.g. switch statements, but can also happen with goto or > simply with unreachable code (which it's still important to not crash on). I'm not sure why BB->begin() wouldn't be the right place to insert a call when a scope is entered after a ternary expression. Is it because EmitConditionalOperatorLValue inserts a phi at the beginning of block "cond.end"? Also, I'm not sure when goto or unreachable code might be mis-compiled. Could you elaborate further on that? I can see now why lifetime.start can be inserted at a wrong location when lowering switch statements because EmitSwitchStmt creates and inserts a SwitchInst before a lexical scope is entered, but I'm not sure about the other two cases you mentioned. https://reviews.llvm.org/D27680 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
