From 59ceb985c7f78ca5dba6b83ff126d97d86267d7c Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Wed, 14 Apr 2021 12:44:04 -0400
Subject: [PATCH] cmd/link: make Loader.SymName not crash

Even if not presented with a valid symbol, recover gracefully,
so that debug prints do not crash.

Change-Id: I06bbe4bec5f90b79b4830e772a7fc3d7c919df1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/312036
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
---
 src/cmd/link/internal/loader/loader.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go
index 141dd0ac688..d5331b3fef1 100644
--- a/src/cmd/link/internal/loader/loader.go
+++ b/src/cmd/link/internal/loader/loader.go
@@ -771,6 +771,9 @@ func (l *Loader) SymName(i Sym) string {
 		return pp.name
 	}
 	r, li := l.toLocal(i)
+	if r == nil {
+		return "?"
+	}
 	name := r.Sym(li).Name(r.Reader)
 	if !r.NeedNameExpansion() {
 		return name