Use registry in gdbarch

gdbarch implements its own registry-like approach.  This patch changes
it to instead use registry.h.  It's a rather large patch but largely
uninteresting -- it's mostly a straightforward conversion from the old
approach to the new one.

The main benefit of this change is that it introduces type safety to
the gdbarch registry.  It also removes a bunch of code.

One possible drawback is that, previously, the gdbarch registry
differentiated between pre- and post-initialization setup.  This
doesn't seem very important to me, though.

1 files changed, 6 insertions, 26 deletions

diff --git a/gdb/dwarf2/expr.c b/gdb/dwarf2/expr.c
index 9986258..3549745 100644
--- a/gdb/dwarf2/expr.c
+++ b/gdb/dwarf2/expr.c
@@ -34,30 +34,17 @@
 #include "gdbarch.h"
 #include "objfiles.h"
 
-/* Cookie for gdbarch data.  */
-
-static struct gdbarch_data *dwarf_arch_cookie;
-
 /* This holds gdbarch-specific types used by the DWARF expression
    evaluator.  See comments in execute_stack_op.  */
 
 struct dwarf_gdbarch_types
 {
-  struct type *dw_types[3];
+  struct type *dw_types[3] {};
 };
 
-/* Allocate and fill in dwarf_gdbarch_types for an arch.  */
-
-static void *
-dwarf_gdbarch_types_init (struct gdbarch *gdbarch)
-{
-  struct dwarf_gdbarch_types *types
-    = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct dwarf_gdbarch_types);
-
-  /* The types themselves are lazily initialized.  */
+/* Cookie for gdbarch data.  */
 
-  return types;
-}
+static const registry<gdbarch>::key<dwarf_gdbarch_types> dwarf_arch_cookie;
 
 /* Ensure that a FRAME is defined, throw an exception otherwise.  */
 
@@ -701,8 +688,9 @@ struct type *
 dwarf_expr_context::address_type () const
 {
   gdbarch *arch = this->m_per_objfile->objfile->arch ();
-  dwarf_gdbarch_types *types
-    = (dwarf_gdbarch_types *) gdbarch_data (arch, dwarf_arch_cookie);
+  dwarf_gdbarch_types *types = dwarf_arch_cookie.get (arch);
+  if (types == nullptr)
+    types = dwarf_arch_cookie.emplace (arch);
   int ndx;
 
   if (this->m_addr_size == 2)
@@ -2398,11 +2386,3 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
   this->m_recursion_depth--;
   gdb_assert (this->m_recursion_depth >= 0);
 }
-
-void _initialize_dwarf2expr ();
-void
-_initialize_dwarf2expr ()
-{
-  dwarf_arch_cookie
-    = gdbarch_data_register_post_init (dwarf_gdbarch_types_init);
-}