From 6f8b69fcd1a5a729449bd44c15805132398734d3 Mon Sep 17 00:00:00 2001
From: David Henningsson <diwic@ubuntu.com>
Date: Fri, 29 Sep 2017 11:00:08 +0200
Subject: [PATCH] Mir pretty print: Add cleanup comment

I found it useful to add a comment indicating whether or not a
BasicBlock is a cleanup block or not. Hopefully you'll find it
useful too.
---
 src/librustc_mir/util/pretty.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/librustc_mir/util/pretty.rs b/src/librustc_mir/util/pretty.rs
index 0811783a9e57f..9e1f05f6d2f77 100644
--- a/src/librustc_mir/util/pretty.rs
+++ b/src/librustc_mir/util/pretty.rs
@@ -188,7 +188,9 @@ pub fn write_basic_block(tcx: TyCtxt,
     let data = &mir[block];
 
     // Basic block label at the top.
-    writeln!(w, "{}{:?}: {{", INDENT, block)?;
+    let cleanup_text = if data.is_cleanup { " // cleanup" } else { "" };
+    let lbl = format!("{}{:?}: {{", INDENT, block);
+    writeln!(w, "{0:1$}{2}", lbl, ALIGN, cleanup_text)?;
 
     // List of statements in the middle.
     let mut current_location = Location { block: block, statement_index: 0 };