[dev.typeparams] all: merge master (f22ec51) into dev.typeparams

[gostls13.git] / src / cmd / compile / internal / reflectdata / reflect.go

diff --git a/src/cmd/compile/internal/reflectdata/reflect.go b/src/cmd/compile/internal/reflectdata/reflect.go
index f65841b33c5be882e41d65fa6c04db1d79fc5f7a..3576a23db9f34f07c57acec1cfd4af698bdfb936 100644 (file)
--- a/src/cmd/compile/internal/reflectdata/reflect.go
+++ b/src/cmd/compile/internal/reflectdata/reflect.go
@@ -1116,6 +1116,15 @@ func writeType(t *types.Type) *obj.LSym {
                }
                ot = objw.Uint32(lsym, ot, flags)
                ot = dextratype(lsym, ot, t, 0)
+               if u := t.Underlying(); u != t {
+                       // If t is a named map type, also keep the underlying map
+                       // type live in the binary. This is important to make sure that
+                       // a named map and that same map cast to its underlying type via
+                       // reflection, use the same hash function. See issue 37716.
+                       r := obj.Addrel(lsym)
+                       r.Sym = writeType(u)
+                       r.Type = objabi.R_KEEP
+               }
 
        case types.TPTR:
                if t.Elem().Kind() == types.TANY {