IR: Document horrible abuse of loose DIDescriptor, NFC

I'll circle back and fix this somehow; for now I just don't want to
forget about it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228608 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/IR/DebugInfo.h b/include/llvm/IR/DebugInfo.h
index fd8ed81..d2a5fb2 100644 (file)
--- a/include/llvm/IR/DebugInfo.h
+++ b/include/llvm/IR/DebugInfo.h
@@ -691,6 +691,8 @@ class DILexicalBlockFile : public DIScope {
 public:
   explicit DILexicalBlockFile(const MDNode *N = nullptr) : DIScope(N) {}
   DIScope getContext() const {
+    // FIXME: This logic is horrible.  getScope() returns a DILexicalBlock, but
+    // then we check if it's a subprogram?  WHAT?!?
     if (getScope().isSubprogram())
       return getScope();
     return getScope().getContext();