[PATCH] D38830: [DWARF] Fix bad comparator in sortGlobalExprs.

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

See also https://bugs.llvm.org//show_bug.cgi?id=34921 .

> you should be able to strip out everything from the IR that is not a global variable and not reachable via a !DIGlobalVariable metadata node

Okay.  Actually, I probably also need to dump out the IR sometime after GlobalMerge runs (for some reason, the crash doesn't trigger otherwise), but I'll figure something out.



================
Comment at: lib/CodeGen/AsmPrinter/DwarfDebug.cpp:514
+              if (!A.Expr || !B.Expr)
+                return !!B.Expr;
+              auto FragmentA = A.Expr->getFragmentInfo();
----------------
aprantl wrote:
> Does `return !A.Expr` achieve the same thing and is easier to read?
Suppose A.Expr and B.Expr are null.  Then the comparator should return false, but !A.Expr is true.


Repository:
  rL LLVM

https://reviews.llvm.org/D38830