gdb: add supports_arch_info callback to gdbarch_register

In the ROCm GDB port, there are some amdgcn architectures known by BFD
that we don't actually support in GDB.  We don't want
gdbarch_printable_names to return these architectures.

gdbarch_printable_names is used for a few things:

 - completion of the "set architecture" command
 - the gdb.architecture_names function in Python
 - foreach-arch selftests

Add an optional callback to gdbarch_register that is a predicate
indicating whether the gdbarch supports the given bfd_arch_info.  by
default, it is nullptr, meaning that the gdbarch accepts all "mach"s for
that architecture known by BFD.

Change-Id: I712f94351b0b34ed1f42e5cf7fc7ba051315d860
Co-Authored-By: Simon Marchi <simon.marchi@efficios.com>
Approved-By: Andrew Burgess <aburgess@redhat.com>

diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c
index 67968126488e9b22d03475683ba48aceea26c0e6..617768225d32726ee7623f546f7ae2f13d1d7099 100644 (file)
--- a/gdb/arch-utils.c
+++ b/gdb/arch-utils.c
@@ -1237,6 +1237,7 @@ struct gdbarch_registration
   enum bfd_architecture bfd_architecture;
   gdbarch_init_ftype *init;
   gdbarch_dump_tdep_ftype *dump_tdep;
+  gdbarch_supports_arch_info_ftype *supports_arch_info;
   struct gdbarch_list *arches;
   struct gdbarch_registration *next;
 };
@@ -1260,7 +1261,9 @@ gdbarch_printable_names ()
        internal_error (_("gdbarch_architecture_names: multi-arch unknown"));
       do
        {
-         arches.push_back (ap->printable_name);
+         if (rego->supports_arch_info == nullptr
+             || rego->supports_arch_info (ap))
+           arches.push_back (ap->printable_name);
          ap = ap->next;
        }
       while (ap != NULL);
@@ -1273,7 +1276,8 @@ gdbarch_printable_names ()
 void
 gdbarch_register (enum bfd_architecture bfd_architecture,
                  gdbarch_init_ftype *init,
-                 gdbarch_dump_tdep_ftype *dump_tdep)
+                 gdbarch_dump_tdep_ftype *dump_tdep,
+                 gdbarch_supports_arch_info_ftype *supports_arch_info)
 {
   struct gdbarch_registration **curr;
   const struct bfd_arch_info *bfd_arch_info;
@@ -1306,6 +1310,7 @@ gdbarch_register (enum bfd_architecture bfd_architecture,
   (*curr)->bfd_architecture = bfd_architecture;
   (*curr)->init = init;
   (*curr)->dump_tdep = dump_tdep;
+  (*curr)->supports_arch_info = supports_arch_info;
   (*curr)->arches = NULL;
   (*curr)->next = NULL;
 }

diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index a1167f21ecac854caed8ac00a814fa7491d006df..f4efd8c0bc7891878980736288d66b1cac90bb6d 100644 (file)
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -270,10 +270,12 @@ struct gdbarch_info
 
 typedef struct gdbarch *(gdbarch_init_ftype) (struct gdbarch_info info, struct gdbarch_list *arches);
 typedef void (gdbarch_dump_tdep_ftype) (struct gdbarch *gdbarch, struct ui_file *file);
+typedef bool (gdbarch_supports_arch_info_ftype) (const struct bfd_arch_info *);
 
 extern void gdbarch_register (enum bfd_architecture architecture,
                              gdbarch_init_ftype *init,
-                             gdbarch_dump_tdep_ftype *dump_tdep = nullptr);
+                             gdbarch_dump_tdep_ftype *dump_tdep = nullptr,
+                             gdbarch_supports_arch_info_ftype *supports_arch_info = nullptr);
 
 
 /* Return a vector of the valid architecture names.  Since architectures are