Remove use of deprecated_add_core_fns in cris_tdep.c

The non-deprecated equivalent is implementing the gdbarch function
iterate_over_regset_sections, this patch does that.

Tested by generating a core file on cris under qemu and comparing
the output of "info registers".

This also fixes this warning when loading cris core files:
  warning: Unexpected size of section `.reg/164' in core file.

gdb/ChangeLog:

2020-02-11  Christian Biesinger  <cbiesinger@google.com>

	* cris-tdep.c (cris_supply_gregset): Change signature to match
	what struct regset expects.
	(cris_regset): New struct.
	(fetch_core_registers): Remove.
	(cris_iterate_over_regset_sections): New function.
	(_initialize_cris_tdep): Don't call deprecated_add_core_fns.
	(cris_gdbarch_init): Call set_gdbarch_iterate_over_regset_sections.

Change-Id: Ieef895b5a2fdc797d1a913cd1c0c07563edfe8e7

2 files changed, 37 insertions, 43 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 93ad9d0..91d7cec 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,15 @@
 2020-02-11  Christian Biesinger  <cbiesinger@google.com>
 
+	* cris-tdep.c (cris_supply_gregset): Change signature to match
+	what struct regset expects.
+	(cris_regset): New struct.
+	(fetch_core_registers): Remove.
+	(cris_iterate_over_regset_sections): New function.
+	(_initialize_cris_tdep): Don't call deprecated_add_core_fns.
+	(cris_gdbarch_init): Call set_gdbarch_iterate_over_regset_sections.
+
+2020-02-11  Christian Biesinger  <cbiesinger@google.com>
+
 	* arch/arm.h (enum gdb_regnum): Add comment for the FP0..7
 	registers.
 
diff --git a/gdb/cris-tdep.c b/gdb/cris-tdep.c
index cc45a7f..e619811 100644
--- a/gdb/cris-tdep.c
+++ b/gdb/cris-tdep.c
@@ -37,6 +37,7 @@
 #include "osabi.h"
 #include "arch-utils.h"
 #include "regcache.h"
+#include "regset.h"
 
 #include "objfiles.h"
 
@@ -3761,21 +3762,28 @@ typedef cris_elf_greg_t crisv32_elf_gregset_t[CRISV32_ELF_NGREG];
 /* Unpack a cris_elf_gregset_t into GDB's register cache.  */
 
 static void 
-cris_supply_gregset (struct regcache *regcache, cris_elf_gregset_t *gregsetp)
+cris_supply_gregset (const struct regset *regset, struct regcache *regcache,
+		     int regnum, const void *gregs, size_t len)
 {
   struct gdbarch *gdbarch = regcache->arch ();
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   int i;
-  cris_elf_greg_t *regp = *gregsetp;
+  const cris_elf_greg_t *regp = static_cast<const cris_elf_greg_t *>(gregs);
+
+  if (len != sizeof (cris_elf_gregset_t)
+      && len != sizeof (crisv32_elf_gregset_t))
+    warning (_("wrong size gregset struct in core file"));
+  gdb_assert (len >= sizeof (crisv32_elf_gregset_t));
 
   /* The kernel dumps all 32 registers as unsigned longs, but supply_register
      knows about the actual size of each register so that's no problem.  */
   for (i = 0; i < NUM_GENREGS + NUM_SPECREGS; i++)
     {
-      regcache->raw_supply (i, (char *)&regp[i]);
+      if (regnum == -1 || regnum == i)
+	regcache->raw_supply (i, (char *)&regp[i]);
     }
 
-  if (tdep->cris_version == 32)
+  if (tdep->cris_version == 32 && (regnum == -1 || regnum == ERP_REGNUM))
     {
       /* Needed to set pseudo-register PC for CRISv32.  */
       /* FIXME: If ERP is in a delay slot at this point then the PC will
@@ -3788,47 +3796,24 @@ cris_supply_gregset (struct regcache *regcache, cris_elf_gregset_t *gregsetp)
     }
 }
 
-/*  Use a local version of this function to get the correct types for
-    regsets, until multi-arch core support is ready.  */
+static const struct regset cris_regset = {
+  nullptr,
+  cris_supply_gregset,
+  /* We don't need a collect function because we only use this for core files
+     (via iterate_over_regset_sections).  */
+  nullptr,
+  REGSET_VARIABLE_SIZE
+};
 
-static void
-fetch_core_registers (struct regcache *regcache,
-		      gdb_byte *core_reg_sect, unsigned core_reg_size,
-                      int which, CORE_ADDR reg_addr)
+static void cris_iterate_over_regset_sections (struct gdbarch *gdbarch,
+					       iterate_over_regset_sections_cb *cb,
+					       void *cb_data,
+					       const struct regcache *regcache)
 {
-  cris_elf_gregset_t gregset;
-
-  switch (which)
-    {
-    case 0:
-      if (core_reg_size != sizeof (cris_elf_gregset_t)
-	  && core_reg_size != sizeof (crisv32_elf_gregset_t))
-        {
-          warning (_("wrong size gregset struct in core file"));
-        }
-      else
-        {
-          memcpy (&gregset, core_reg_sect, sizeof (gregset));
-          cris_supply_gregset (regcache, &gregset);
-        }
-
-    default:
-      /* We've covered all the kinds of registers we know about here,
-         so this must be something we wouldn't know what to do with
-         anyway.  Just ignore it.  */
-      break;
-    }
+  cb (".reg", sizeof (crisv32_elf_gregset_t), sizeof (crisv32_elf_gregset_t),
+      &cris_regset, NULL, cb_data);
 }
 
-static struct core_fns cris_elf_core_fns =
-{
-  bfd_target_elf_flavour,               /* core_flavour */
-  default_check_format,                 /* check_format */
-  default_core_sniffer,                 /* core_sniffer */
-  fetch_core_registers,                 /* core_read_registers */
-  NULL                                  /* next */
-};
-
 void _initialize_cris_tdep ();
 void
 _initialize_cris_tdep ()
@@ -3868,8 +3853,6 @@ Makes GDB use the NRP register instead of the ERP register in certain cases."),
 			   NULL, /* FIXME: i18n: Usage of Dwarf-2 CFI
 				    for CRIS is %d.  */
 			   &setlist, &showlist);
-
-  deprecated_add_core_fns (&cris_elf_core_fns);
 }
 
 /* Prints out all target specific values.  */
@@ -4059,6 +4042,7 @@ cris_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 
   set_gdbarch_breakpoint_kind_from_pc (gdbarch, cris_breakpoint_kind_from_pc);
   set_gdbarch_sw_breakpoint_from_kind (gdbarch, cris_sw_breakpoint_from_kind);
+  set_gdbarch_iterate_over_regset_sections (gdbarch, cris_iterate_over_regset_sections);
   
   if (tdep->cris_dwarf2_cfi == 1)
     {