From: Keith Randall <khr@golang.org>
Date: Fri, 22 Oct 2021 01:28:50 +0000 (-0700)
Subject: cmd/link: escape % characters in symbols when reporting errors
X-Git-Tag: go1.18beta1~769
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=f92c8f07ace7ae67b95e59bbb6ae6928dd6e4773;p=gostls13.git

cmd/link: escape % characters in symbols when reporting errors

Generic function symbols sometimes have % in them, like:

    main.B2[%2eshape.string_0].m2·f

Which confuses this code because it doesn't esacpe % when
using this string as a format string, instead of a format argument.

Or could we get rid of the . -> %2e rewrite somehow?
I think it comes from LinkString.

Change-Id: I3275501f44cf30485e9d4577e0dfa77996d4939e
Reviewed-on: https://go-review.googlesource.com/c/go/+/357837
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
---

diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go
index 9b7888e940..34c1c6a4c8 100644
--- a/src/cmd/link/internal/loader/loader.go
+++ b/src/cmd/link/internal/loader/loader.go
@@ -2592,7 +2592,9 @@ type ErrorReporter struct {
 //
 func (reporter *ErrorReporter) Errorf(s Sym, format string, args ...interface{}) {
 	if s != 0 && reporter.ldr.SymName(s) != "" {
-		format = reporter.ldr.SymName(s) + ": " + format
+		// Note: Replace is needed here because symbol names might have % in them,
+		// due to the use of LinkString for names of instantiating types.
+		format = strings.Replace(reporter.ldr.SymName(s), "%", "%%", -1) + ": " + format
 	} else {
 		format = fmt.Sprintf("sym %d: %s", s, format)
 	}