all: document legacy //go:linkname for modules with ≥200 dependents

Ignored these linknames which have not worked for a while:

github.com/xtls/xray-core:
	context.newCancelCtx removed in CL 463999 (Feb 2023)

github.com/u-root/u-root:
	funcPC removed in CL 513837 (Jul 2023)

tinygo.org/x/drivers:
	net.useNetdev never existed

For #67401.

Change-Id: I9293f4ef197bb5552b431de8939fa94988a060ce
Reviewed-on: https://go-review.googlesource.com/c/go/+/587576
Auto-Submit: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/src/runtime/type.go b/src/runtime/type.go
index a2975c4a99..201340752b 100644
--- a/src/runtime/type.go
+++ b/src/runtime/type.go
@@ -106,6 +106,15 @@ func reflectOffsUnlock() {
 	unlock(&reflectOffs.lock)
 }
 
+// resolveNameOff should be an internal detail,
+// but widely used packages access it using linkname.
+// Notable members of the hall of shame include:
+//   - github.com/cloudwego/frugal
+//
+// Do not remove or change the type signature.
+// See go.dev/issue/67401.
+//
+//go:linkname resolveNameOff
 func resolveNameOff(ptrInModule unsafe.Pointer, off nameOff) name {
 	if off == 0 {
 		return name{}
@@ -140,6 +149,15 @@ func (t rtype) nameOff(off nameOff) name {
 	return resolveNameOff(unsafe.Pointer(t.Type), off)
 }
 
+// resolveTypeOff should be an internal detail,
+// but widely used packages access it using linkname.
+// Notable members of the hall of shame include:
+//   - github.com/cloudwego/frugal
+//
+// Do not remove or change the type signature.
+// See go.dev/issue/67401.
+//
+//go:linkname resolveTypeOff
 func resolveTypeOff(ptrInModule unsafe.Pointer, off typeOff) *_type {
 	if off == 0 || off == -1 {
 		// -1 is the sentinel value for unreachable code.