From 37c00c41f82e50c3b3ca43326faa6ccb909fb2b5 Mon Sep 17 00:00:00 2001
From: varkor <github@varkor.com>
Date: Wed, 7 Oct 2020 19:31:23 +0100
Subject: [PATCH] Do not print type for placeholder values

---
 compiler/rustc_symbol_mangling/src/v0.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs
index 8c6ed7bd1407..7833385cbc99 100644
--- a/compiler/rustc_symbol_mangling/src/v0.rs
+++ b/compiler/rustc_symbol_mangling/src/v0.rs
@@ -548,9 +548,10 @@ impl Printer<'tcx> for SymbolMangler<'tcx> {
                 bug!("symbol_names: unsupported constant of type `{}` ({:?})", ct.ty, ct);
             }
         };
-        self = ct.ty.print(self)?;
 
         if let Some(bits) = val {
+            // We only print the type if the const can be evaluated.
+            self = ct.ty.print(self)?;
             let _ = write!(self.out, "{}{:x}_", if neg { "n" } else { "" }, bits);
         } else {
             // NOTE(eddyb) despite having the path, we need to