From: Joel Sing <joel@sing.id.au>
Date: Thu, 2 Mar 2023 14:24:06 +0000 (+1100)
Subject: debug/dwarf: return ErrUnknownPC rather than nil on unknown PC
X-Git-Tag: go1.21rc1~1225
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=20e9b7f1b53d49fd66e0344b1d0d42d3cf5e47b6;p=gostls13.git

debug/dwarf: return ErrUnknownPC rather than nil on unknown PC

Currently, on e == nil or e.Tag == 0, SeekPC returns with a nil error.
Instead, indicate that the PC is unknown.

Change-Id: I9594296034e2df872e399bd800b00cb565c413c9
Reviewed-on: https://go-review.googlesource.com/c/go/+/473695
Reviewed-by: Carlos Amedee <carlos@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
---

diff --git a/src/debug/dwarf/entry.go b/src/debug/dwarf/entry.go
index 5bb4297b48..f1215d2b01 100644
--- a/src/debug/dwarf/entry.go
+++ b/src/debug/dwarf/entry.go
@@ -975,9 +975,12 @@ func (r *Reader) SeekPC(pc uint64) (*Entry, error) {
 		u := &r.d.unit[unit]
 		r.b = makeBuf(r.d, u, "info", u.off, u.data)
 		e, err := r.Next()
-		if err != nil || e == nil || e.Tag == 0 {
+		if err != nil {
 			return nil, err
 		}
+		if e == nil || e.Tag == 0 {
+			return nil, ErrUnknownPC
+		}
 		ranges, err := r.d.Ranges(e)
 		if err != nil {
 			return nil, err