gdb: always add the default register groups

There's a set of 7 default register groups.  If we don't add any
gdbarch specific register groups during gdbarch initialisation, then
when we iterate over the register groups using reggroup_next and
reggroup_prev we will make use of these 7 default groups.  See the use
of default_groups in gdb/reggroups.c for details on this.

However, if the gdbarch adds its own groups during gdbarch
initialisation, then these groups will be used in preference to the
default groups.

A problem arises though if the particular architecture makes use of
the target description mechanism.  If the default target
description(s) (i.e. those internal to GDB that are used when the user
doesn't provide their own) don't mention any additional register
groups then the default register groups will be used.

But if the target description does mention additional groups then the
default groups are not used, and instead, the groups from the target
description are used.

The problem with this is that what usually happens is that the target
description will mention additional groups, e.g. groups for special
registers.  Most architectures that use target descriptions work
around this by adding all (or most) of the default register groups in
all cases.  See i386_add_reggroups, aarch64_add_reggroups,
riscv_add_reggroups, xtensa_add_reggroups, and others.

In this patch, my suggestion is that we should just add the default
register groups for every architecture, always.  This change is in
gdb/reggroups.c.

All the remaining changes are me updating the various architectures to
not add the default groups themselves.

So, where will this change be visible to the user?  I think the
following commands will possibly change:

* info registers / info all-registers:

  The user can provide a register group to these commands.  For example,
  on csky, we previously never added the 'vector' group.  Now, as a
  default group, this will be available, but (presumably) will not
  contain any registers.  I don't think this is necessarily a bad
  thing, there's something to be said for having some consistent
  defaults available.  There are other architectures that didn't add
  all 7 of the defaults, which will now have gained additional groups.

* maint print reggroups

  This prints the set of all available groups.  As a maintenance
  command I'm less concerned with the output changing here.
  Obviously, for the architectures that didn't previously add all the
  defaults, this list just got bigger.

* maint print register-groups

  This prints all the registers, and the groups they are in.  If the
  defaults were not previously being added then a register (obviously)
  can't appear in one of the default groups.  Now the groups are
  available then registers might be in more groups than previously.
  However, this is again a maintenance command, so I'm less concerned
  about this changing.

diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index cdeeece83c0d1350266ba53c8965b680ef972441..98eaeaf8ca41a55734b7ffc2b7f1e48ede052475 100644 (file)
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -3367,20 +3367,6 @@ aarch64_get_tdesc_vq (const struct target_desc *tdesc)
   return sve_vq_from_vl (vl);
 }
 
-/* Add all the expected register sets into GDBARCH.  */
-
-static void
-aarch64_add_reggroups (struct gdbarch *gdbarch)
-{
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-}
-
 /* Implement the "cannot_store_register" gdbarch method.  */
 
 static int
@@ -3636,9 +3622,6 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   /* Virtual tables.  */
   set_gdbarch_vbit_in_delta (gdbarch, 1);
 
-  /* Register architecture.  */
-  aarch64_add_reggroups (gdbarch);
-
   /* Hook in the ABI-specific overrides, if they have been registered.  */
   info.target_desc = tdesc;
   info.tdesc_data = tdesc_data.get ();

diff --git a/gdb/arc-tdep.c b/gdb/arc-tdep.c
index d6da2886c499151459ab26623cfa24e413888e96..98bd1c4bc0a6ea775bc7767bfe671233a5f9c3c8 100644 (file)
--- a/gdb/arc-tdep.c
+++ b/gdb/arc-tdep.c
@@ -1952,20 +1952,6 @@ static const struct frame_base arc_normal_base = {
   arc_frame_base_address
 };
 
-/* Add all the expected register sets into GDBARCH.  */
-
-static void
-arc_add_reggroups (struct gdbarch *gdbarch)
-{
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-}
-
 static enum arc_isa
 mach_type_to_arc_isa (const unsigned long mach)
 {
@@ -2364,9 +2350,6 @@ arc_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   /* This doesn't include possible long-immediate value.  */
   set_gdbarch_max_insn_length (gdbarch, 4);
 
-  /* Add default register groups.  */
-  arc_add_reggroups (gdbarch);
-
   /* Frame unwinders and sniffers.  */
   dwarf2_frame_set_init_reg (gdbarch, arc_dwarf2_frame_init_reg);
   dwarf2_append_unwinders (gdbarch);

diff --git a/gdb/csky-tdep.c b/gdb/csky-tdep.c
index f1376730c8740dd3de1db160d83c94a22ff0e9f5..feb416a2406847d2f821f3ddc80f119ab87af89b 100644 (file)
--- a/gdb/csky-tdep.c
+++ b/gdb/csky-tdep.c
@@ -2050,8 +2050,6 @@ csky_init_reggroup ()
 static void
 csky_add_reggroups (struct gdbarch *gdbarch)
 {
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
   reggroup_add (gdbarch, cr_reggroup);
   reggroup_add (gdbarch, fr_reggroup);
   reggroup_add (gdbarch, vr_reggroup);

diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 400ccd6bebf29f1652a1966bd38068a7badcbc0c..99a81b98da113cafa1047487bcd580d3bc224f7a 100644 (file)
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -4546,13 +4546,6 @@ i386_add_reggroups (struct gdbarch *gdbarch)
 {
   reggroup_add (gdbarch, i386_sse_reggroup);
   reggroup_add (gdbarch, i386_mmx_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
 }
 
 int

diff --git a/gdb/lm32-tdep.c b/gdb/lm32-tdep.c
index f3f1f87d6bb458e6345b52b41a48a624b4251b62..4a781c394e9569115b5a66282ff9773ee76a372e 100644 (file)
--- a/gdb/lm32-tdep.c
+++ b/gdb/lm32-tdep.c
@@ -59,16 +59,6 @@ struct lm32_frame_cache
   trad_frame_saved_reg *saved_regs;
 };
 
-/* Add the available register groups.  */
-
-static void
-lm32_add_reggroups (struct gdbarch *gdbarch)
-{
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-}
-
 /* Return whether a given register is in a given group.  */
 
 static int
@@ -540,7 +530,6 @@ lm32_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   set_gdbarch_push_dummy_call (gdbarch, lm32_push_dummy_call);
   set_gdbarch_return_value (gdbarch, lm32_return_value);
 
-  lm32_add_reggroups (gdbarch);
   set_gdbarch_register_reggroup_p (gdbarch, lm32_register_reggroup_p);
 
   return gdbarch;

diff --git a/gdb/m32c-tdep.c b/gdb/m32c-tdep.c
index 94087302892ad781ffdb1e725aa4b819e8ff2b24..5a767c9ed523fe28a38612c14fdfee7dcec787fb 100644 (file)
--- a/gdb/m32c-tdep.c
+++ b/gdb/m32c-tdep.c
@@ -981,11 +981,6 @@ make_regs (struct gdbarch *arch)
   set_gdbarch_dwarf2_reg_to_regnum (arch, m32c_debug_info_reg_to_regnum);
   set_gdbarch_register_reggroup_p (arch, m32c_register_reggroup_p);
 
-  reggroup_add (arch, general_reggroup);
-  reggroup_add (arch, all_reggroup);
-  reggroup_add (arch, save_reggroup);
-  reggroup_add (arch, restore_reggroup);
-  reggroup_add (arch, system_reggroup);
   reggroup_add (arch, m32c_dma_reggroup);
 }
 

diff --git a/gdb/m68hc11-tdep.c b/gdb/m68hc11-tdep.c
index f1133fe6780a52a1cb54fa4961192a62461d0c76..9d978d8801804f8fb5cb03ce115e7a521f0ba1de 100644 (file)
--- a/gdb/m68hc11-tdep.c
+++ b/gdb/m68hc11-tdep.c
@@ -1361,13 +1361,6 @@ m68hc11_add_reggroups (struct gdbarch *gdbarch)
 {
   reggroup_add (gdbarch, m68hc11_hard_reggroup);
   reggroup_add (gdbarch, m68hc11_soft_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
 }
 
 static int

diff --git a/gdb/mep-tdep.c b/gdb/mep-tdep.c
index 8f2f0a3b30d9897f2e386903fffd5635415c9cf4..1ab01c6cbb3d689331423cf1b7dc94b90138e589 100644 (file)
--- a/gdb/mep-tdep.c
+++ b/gdb/mep-tdep.c
@@ -2427,10 +2427,6 @@ mep_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   set_gdbarch_stab_reg_to_regnum (gdbarch, mep_debug_reg_to_regnum);
 
   set_gdbarch_register_reggroup_p (gdbarch, mep_register_reggroup_p);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
   reggroup_add (gdbarch, mep_csr_reggroup);
   reggroup_add (gdbarch, mep_cr_reggroup);
   reggroup_add (gdbarch, mep_ccr_reggroup);

diff --git a/gdb/nds32-tdep.c b/gdb/nds32-tdep.c
index 425d7d90d64f1b034c889af1c9d844e0adfd8f74..a94a03ab2ab2997ac33d6232fb7a5f4bc99dce34 100644 (file)
--- a/gdb/nds32-tdep.c
+++ b/gdb/nds32-tdep.c
@@ -343,14 +343,6 @@ nds32_init_reggroups (void)
 static void
 nds32_add_reggroups (struct gdbarch *gdbarch)
 {
-  /* Add pre-defined register groups.  */
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-
   /* Add NDS32 register groups.  */
   reggroup_add (gdbarch, nds32_cr_reggroup);
   reggroup_add (gdbarch, nds32_ir_reggroup);

diff --git a/gdb/or1k-tdep.c b/gdb/or1k-tdep.c
index 9f7fa2f169f0c643045a75fed5cef3146268dd4b..2b906fa69d3170b69474d731ac7f07b0c432e6ec 100644 (file)
--- a/gdb/or1k-tdep.c
+++ b/gdb/or1k-tdep.c
@@ -1260,19 +1260,7 @@ or1k_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
     }
 
   if (tdesc_data != NULL)
-    {
-      /* If we are using tdesc, register our own reggroups, otherwise we
-        will used the defaults.  */
-      reggroup_add (gdbarch, general_reggroup);
-      reggroup_add (gdbarch, system_reggroup);
-      reggroup_add (gdbarch, float_reggroup);
-      reggroup_add (gdbarch, vector_reggroup);
-      reggroup_add (gdbarch, all_reggroup);
-      reggroup_add (gdbarch, save_reggroup);
-      reggroup_add (gdbarch, restore_reggroup);
-
-      tdesc_use_registers (gdbarch, tdesc, std::move (tdesc_data));
-    }
+    tdesc_use_registers (gdbarch, tdesc, std::move (tdesc_data));
 
   /* Hook in ABI-specific overrides, if they have been registered.  */
   gdbarch_init_osabi (info, gdbarch);

diff --git a/gdb/reggroups.c b/gdb/reggroups.c
index 6c38ca743f4c916a9938f44e9528221038d69e5a..74b981fb5e9030a4cac6c42ce16a707c5ce039a1 100644 (file)
--- a/gdb/reggroups.c
+++ b/gdb/reggroups.c
@@ -90,15 +90,6 @@ struct reggroups
 
 static struct gdbarch_data *reggroups_data;
 
-static void *
-reggroups_init (struct obstack *obstack)
-{
-  struct reggroups *groups = OBSTACK_ZALLOC (obstack, struct reggroups);
-
-  groups->last = &groups->first;
-  return groups;
-}
-
 /* Add a register group (with attribute values) to the pre-defined
    list.  */
 
@@ -119,13 +110,42 @@ reggroup_add (struct gdbarch *gdbarch, struct reggroup *group)
   struct reggroups *groups
     = (struct reggroups *) gdbarch_data (gdbarch, reggroups_data);
 
+  /* The same reggroup should not be added multiple times.  */
+  gdb_assert (groups != nullptr);
+  for (struct reggroup_el *el = groups->first; el != nullptr; el = el->next)
+    gdb_assert (group != el->group);
+
   add_group (groups, group,
             GDBARCH_OBSTACK_ZALLOC (gdbarch, struct reggroup_el));
 }
 
-/* The default register groups for an architecture.  */
+/* Called to initialize the per-gdbarch register group information.  */
 
-static struct reggroups default_groups = { NULL, &default_groups.first };
+static void *
+reggroups_init (struct obstack *obstack)
+{
+  struct reggroups *groups = OBSTACK_ZALLOC (obstack, struct reggroups);
+
+  groups->last = &groups->first;
+
+  /* Add the default groups.  */
+  add_group (groups, general_reggroup,
+            OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, float_reggroup,
+            OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, system_reggroup,
+            OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, vector_reggroup,
+            OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, all_reggroup,
+            OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, save_reggroup,
+            OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, restore_reggroup,
+            OBSTACK_ZALLOC (obstack, struct reggroup_el));
+
+  return groups;
+}
 
 /* A register group iterator.  */
 
@@ -139,8 +159,7 @@ reggroup_next (struct gdbarch *gdbarch, const struct reggroup *last)
      creation.  If there are no groups, use the default groups list.  */
   groups = (struct reggroups *) gdbarch_data (gdbarch, reggroups_data);
   gdb_assert (groups != NULL);
-  if (groups->first == NULL)
-    groups = &default_groups;
+  gdb_assert (groups->first != NULL);
 
   /* Return the first/next reggroup.  */
   if (last == NULL)
@@ -171,8 +190,7 @@ reggroup_prev (struct gdbarch *gdbarch, const struct reggroup *curr)
      creation.  If there are no groups, use the default groups list.  */
   groups = (struct reggroups *) gdbarch_data (gdbarch, reggroups_data);
   gdb_assert (groups != NULL);
-  if (groups->first == NULL)
-    groups = &default_groups;
+  gdb_assert (groups->first != NULL);
 
   prev = NULL;
   for (el = groups->first; el != NULL; el = el->next)
@@ -327,15 +345,6 @@ _initialize_reggroup ()
 {
   reggroups_data = gdbarch_data_register_pre_init (reggroups_init);
 
-  /* The pre-defined list of groups.  */
-  add_group (&default_groups, general_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, float_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, system_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, vector_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, all_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, save_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, restore_reggroup, XNEW (struct reggroup_el));
-
   add_cmd ("reggroups", class_maintenance,
           maintenance_print_reggroups, _("\
 Print the internal register group names.\n\

diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index 8713652b09969fb55aeffa9d6f036cab7f0e3e88..79b8135103941646a8ae9478b3c2f96454b8c8ae 100644 (file)
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -3497,21 +3497,11 @@ riscv_find_default_target_description (const struct gdbarch_info info)
   return riscv_lookup_target_description (features);
 }
 
-/* Add all the expected register sets into GDBARCH.  */
+/* Add all the RISC-V specific register groups into GDBARCH.  */
 
 static void
 riscv_add_reggroups (struct gdbarch *gdbarch)
 {
-  /* Add predefined register groups.  */
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-
-  /* Add RISC-V specific register groups.  */
   reggroup_add (gdbarch, csr_reggroup);
 }
 

diff --git a/gdb/xtensa-tdep.c b/gdb/xtensa-tdep.c
index 62be13643b285a895fff78641bc8c07962fe5013..6e478ee893d67414d2a559ad77886f6a3a04d945 100644 (file)
--- a/gdb/xtensa-tdep.c
+++ b/gdb/xtensa-tdep.c
@@ -734,23 +734,12 @@ xtensa_init_reggroups (void)
 static void
 xtensa_add_reggroups (struct gdbarch *gdbarch)
 {
-  int i;
-
-  /* Predefined groups.  */
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-
   /* Xtensa-specific groups.  */
   reggroup_add (gdbarch, xtensa_ar_reggroup);
   reggroup_add (gdbarch, xtensa_user_reggroup);
   reggroup_add (gdbarch, xtensa_vectra_reggroup);
 
-  for (i = 0; i < XTENSA_MAX_COPROCESSOR; i++)
+  for (int i = 0; i < XTENSA_MAX_COPROCESSOR; i++)
     reggroup_add (gdbarch, xtensa_cp[i]);
 }