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>

diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go
index 141dd0ac688eb6d725c0602b674cf68c7aa23076..d5331b3fef1dd339cc4961c0e987a39a14fae0bd 100644 (file)
--- 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