cmd/link: add ReflectMethod flag to -dumpdep output

Adds ReflectMethod flag to the output of -dumpdep.

Fixes #60221

Change-Id: I631d72ee21b819a3a629780317ff4d962cc121e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/495715
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Cherry Mui <[email protected]>
Run-TryBot: Alessandro Arzilli <[email protected]>
Reviewed-by: Heschi Kreinick <[email protected]>

Author: aarzilli

src/cmd/link/internal/ld/deadcode.go

@@ -325,22 +325,32 @@ func (d *deadcodePass) mark(symIdx, parent loader.Sym) {
 		if *flagDumpDep {
 			to := d.ldr.SymName(symIdx)
 			if to != "" {
-				if d.ldr.AttrUsedInIface(symIdx) {
-					to += " <UsedInIface>"
-				}
+				to = d.dumpDepAddFlags(to, symIdx)
 				from := "_"
 				if parent != 0 {
 					from = d.ldr.SymName(parent)
-					if d.ldr.AttrUsedInIface(parent) {
-						from += " <UsedInIface>"
-					}
+					from = d.dumpDepAddFlags(from, parent)
 				}
 				fmt.Printf("%s -> %s\n", from, to)
 			}
 		}
 	}
 }
 
+func (d *deadcodePass) dumpDepAddFlags(name string, symIdx loader.Sym) string {
+	var flags strings.Builder
+	if d.ldr.AttrUsedInIface(symIdx) {
+		flags.WriteString("<UsedInIface>")
+	}
+	if d.ldr.IsReflectMethod(symIdx) {
+		flags.WriteString("<ReflectMethod>")
+	}
+	if flags.Len() > 0 {
+		return name + " " + flags.String()
+	}
+	return name
+}
+
 func (d *deadcodePass) markMethod(m methodref) {
 	relocs := d.ldr.Relocs(m.src)
 	d.mark(relocs.At(m.r).Sym(), m.src)