compiler: fix crash on struct that embeds pointer type

    The type verification code that enforces rules about the types of
    embedded struct fields was not properly handling the case where the
    pointed-to type is a pointer type, e.g.

      type s *struct{ C int }
      type t struct{ *s }

    which is illegal according to the spec. Tweak the verifier to catch
    this case, and add a guard in the lowering pass to make sure that we
    don't crash on invalid accesses to field "C" in type "t" above.

    Fixes golang/go#22050

    Reviewed-on: https://go-review.googlesource.com/66530

From-SVN: r253236

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index de1369dedac416ba843e8299e692f9359133d1fe..12cba43421a04cce61b5aefa3572c47e79824400 100644 (file)
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-cdf1f58c7578980e1d1949680c7e404961b7c153
+11b7dae7de94215e92eb46e703cfecd76c0a3282
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

diff --git a/gcc/go/gofrontend/types.cc b/gcc/go/gofrontend/types.cc
index a00b80a7e6c414e5767133ea94135c2048fed1e1..b6323f8135e88aa37682d9ab0f269f931bb7a153 100644 (file)
--- a/gcc/go/gofrontend/types.cc
+++ b/gcc/go/gofrontend/types.cc
@@ -5842,7 +5842,9 @@ Struct_type::do_verify()
       Type* t = p->type();
       if (p->is_anonymous())
        {
-         if (t->named_type() != NULL && t->points_to() != NULL)
+         if ((t->named_type() != NULL && t->points_to() != NULL)
+              || (t->named_type() == NULL && t->points_to() != NULL
+                  && t->points_to()->points_to() != NULL))
            {
              go_error_at(p->location(), "embedded type may not be a pointer");
              p->set_type(Type::make_error_type());
@@ -11848,6 +11850,12 @@ Type::bind_field_or_method(Gogo* gogo, const Type* type, Expression* expr,
              go_assert(expr->type()->struct_type() == st);
            }
          ret = st->field_reference(expr, name, location);
+          if (ret == NULL)
+            {
+              go_error_at(location, "type has no field %qs",
+                          Gogo::message_name(name).c_str());
+              return Expression::make_error(location);
+            }
        }
       else if (it != NULL && it->find_method(name) != NULL)
        ret = Expression::make_interface_field_reference(expr, name,