[RFA] Sparc OS abi gdbarch init (was Re: [RFA] Sparc/Linux fixes part 1)

["David S. Miller" <davem@redhat.com>]

   From: Jason R Thorpe <thorpej@wasabisystems.com>
   Date: Sat, 20 Apr 2002 19:24:20 -0700
   
   Cool.  You should be able to lift all the code you need for it
   right from arm-tdep.c
   
Infrastructure implemented thusly, ok to install?

2002-04-20  David S. Miller  <davem@redhat.com>

	* sparc-tdep.h: New file.
	* sparc-tdep.c (elf-bfd.h): Include.
	(SPARC_HAS_FPU, FP_REGISTER_BYTES, FP_MAX_REGNUM,
	SPARC_INTREG_SIZE, DUMMY_REG_SAVE_OFFSET, gdbarch_tdep,
	CALL_DUMMY_CALL_OFFSET): Move out to sparc-tdep.h
	(sparc_dump_tdep): New function.
	(_initialize_sparc_tdep): Use gdbarch_register instead of
	register_gdbarch_init which is deprecated.
	(process_note_abi_tag_sections, sparc_abi_handler,
	sparc_abi_handler_list, sparc_gdbarch_register_os_abi): New.
	(sparc_gdbarch_init): Determine elf os ident key based upon
	either the elf header or by using process_note_abi_tag_sections.
	Fix 'gdbarch already exists' test by comparing os_ident as well.
	As the last action, invoke OS abi_handler if installed.
	
--- ./Makefile.in.~1~	Mon Apr  8 20:06:13 2002
+++ ./Makefile.in	Sat Apr 20 20:18:29 2002
@@ -2053,7 +2053,7 @@ sparc-nat.o: sparc-nat.c $(bfd_h) $(defs
 
 sparc-tdep.o: sparc-tdep.c $(floatformat_h) $(defs_h) $(gdbcore_h) \
 	$(inferior_h) $(objfiles_h) $(symfile_h) $(target_h) $(gdb_string_h) \
-	$(arch_utils_h) $(regcache_h)
+	$(arch_utils_h) $(regcache_h) $(BFD_SRC)/elf-bfd.h sparc-tdep.h
 
 sparcl-tdep.o: sparcl-tdep.c $(defs_h) $(gdbcore_h) $(target_h) $(regcache_h)
 
--- ./sparc-tdep.c.~1~	Fri Apr 19 20:09:28 2002
+++ ./sparc-tdep.c	Sat Apr 20 20:21:56 2002
@@ -34,6 +34,8 @@
 #include "gdb_string.h"
 #include "regcache.h"
 
+#include "elf-bfd.h"
+
 #ifdef	USE_PROC_FS
 #include <sys/procfs.h>
 /* Prototypes for supply_gregset etc. */
@@ -44,74 +46,7 @@
 
 #include "symfile.h" 	/* for 'entry_point_address' */
 
-/*
- * Some local macros that have multi-arch and non-multi-arch versions:
- */
-
-#if (GDB_MULTI_ARCH > 0)
-
-/* Does the target have Floating Point registers?  */
-#define SPARC_HAS_FPU     (gdbarch_tdep (current_gdbarch)->has_fpu)
-/* Number of bytes devoted to Floating Point registers: */
-#define FP_REGISTER_BYTES (gdbarch_tdep (current_gdbarch)->fp_register_bytes)
-/* Highest numbered Floating Point register.  */
-#define FP_MAX_REGNUM     (gdbarch_tdep (current_gdbarch)->fp_max_regnum)
-/* Size of a general (integer) register: */
-#define SPARC_INTREG_SIZE (gdbarch_tdep (current_gdbarch)->intreg_size)
-/* Offset within the call dummy stack of the saved registers.  */
-#define DUMMY_REG_SAVE_OFFSET (gdbarch_tdep (current_gdbarch)->reg_save_offset)
-
-#else /* non-multi-arch */
-
-
-/* Does the target have Floating Point registers?  */
-#if defined(TARGET_SPARCLET) || defined(TARGET_SPARCLITE)
-#define SPARC_HAS_FPU 0
-#else
-#define SPARC_HAS_FPU 1
-#endif
-
-/* Number of bytes devoted to Floating Point registers: */
-#if (GDB_TARGET_IS_SPARC64)
-#define FP_REGISTER_BYTES (64 * 4)
-#else
-#if (SPARC_HAS_FPU)
-#define FP_REGISTER_BYTES (32 * 4)
-#else
-#define FP_REGISTER_BYTES 0
-#endif
-#endif
-
-/* Highest numbered Floating Point register.  */
-#if (GDB_TARGET_IS_SPARC64)
-#define FP_MAX_REGNUM (FP0_REGNUM + 48)
-#else
-#define FP_MAX_REGNUM (FP0_REGNUM + 32)
-#endif
-
-/* Size of a general (integer) register: */
-#define SPARC_INTREG_SIZE (REGISTER_RAW_SIZE (G0_REGNUM))
-
-/* Offset within the call dummy stack of the saved registers.  */
-#if (GDB_TARGET_IS_SPARC64)
-#define DUMMY_REG_SAVE_OFFSET (128 + 16)
-#else
-#define DUMMY_REG_SAVE_OFFSET 0x60
-#endif
-
-#endif /* GDB_MULTI_ARCH */
-
-struct gdbarch_tdep
-  {
-    int has_fpu;
-    int fp_register_bytes;
-    int y_regnum;
-    int fp_max_regnum;
-    int intreg_size;
-    int reg_save_offset;
-    int call_dummy_call_offset;
-    int print_insn_mach;
-  };
+#include "sparc-tdep.h"
 
 /* Now make GDB_TARGET_IS_SPARC64 a runtime test.  */
 /* FIXME MVS: or try testing bfd_arch_info.arch and bfd_arch_info.mach ... 
@@ -2132,11 +2067,6 @@ sparclet_store_return_value (struct type
 }
 
 
-#ifndef CALL_DUMMY_CALL_OFFSET
-#define CALL_DUMMY_CALL_OFFSET \
-     (gdbarch_tdep (current_gdbarch)->call_dummy_call_offset)
-#endif /* CALL_DUMMY_CALL_OFFSET */
-
 /* Insert the function address into a call dummy instruction sequence
    stored at DUMMY.
 
@@ -2237,11 +2167,13 @@ sparc_target_architecture_hook (const bf
 static struct gdbarch * sparc_gdbarch_init (struct gdbarch_info info,
 					    struct gdbarch_list *arches);
 
+static void sparc_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file);
+
 void
 _initialize_sparc_tdep (void)
 {
   /* Hook us into the gdbarch mechanism.  */
-  register_gdbarch_init (bfd_arch_sparc, sparc_gdbarch_init);
+  gdbarch_register (bfd_arch_sparc, sparc_gdbarch_init, sparc_dump_tdep);
 
   tm_print_insn = gdb_print_insn_sparc;
   tm_print_insn_info.mach = TM_PRINT_INSN_MACH;		/* Selects sparc/sparclite */
@@ -2885,6 +2817,92 @@ sparc_return_value_on_stack (struct type
     return 0;
 }
 
+\f
+static void
+process_note_abi_tag_sections (bfd *abfd, asection *sect, void *obj)
+{
+  int *os_ident_ptr = obj;
+  const char *name;
+  unsigned int sect_size;
+
+  name = bfd_get_section_name (abfd, sect);
+  sect_size = bfd_section_size (abfd, sect);
+  if (strcmp (name, ".note.ABI-tag") == 0 && sect_size > 0)
+    {
+      unsigned int name_length, data_length, note_type;
+      char *note = alloca (sect_size);
+
+      bfd_get_section_contents (abfd, sect, note,
+                                (file_ptr) 0, (bfd_size_type) sect_size);
+
+      name_length = bfd_h_get_32 (abfd, note);
+      data_length = bfd_h_get_32 (abfd, note + 4);
+      note_type = bfd_h_get_32 (abfd, note + 8);
+
+      if (name_length == 4 && data_length == 16 && note_type == 1
+          && strcmp (note + 12, "GNU") == 0)
+        {
+          int os_number = bfd_h_get_32 (abfd, note + 16);
+
+          /* The case numbers are from abi-tags in glibc.  */
+          switch (os_number)
+            {
+            case 0:
+              *os_ident_ptr = ELFOSABI_LINUX;
+              break;
+            case 1:
+              *os_ident_ptr = ELFOSABI_HURD;
+              break;
+            case 2:
+              *os_ident_ptr = ELFOSABI_SOLARIS;
+              break;
+            default:
+              internal_error (__FILE__, __LINE__,
+                              "process_note_abi_sections: "
+                              "unknown OS number %d", os_number);
+              break;
+            }
+        }
+    }
+}
+
+struct sparc_abi_handler
+{
+  struct sparc_abi_handler *next;
+  int os_ident;
+  void (*init_abi)(struct gdbarch_info, struct gdbarch *);
+};
+
+struct sparc_abi_handler *sparc_abi_handler_list = NULL;
+
+void
+sparc_gdbarch_register_os_abi (int os_ident,
+			       void (*init_abi)(struct gdbarch_info,
+						struct gdbarch *))
+{
+  struct sparc_abi_handler *p;
+
+  for (p = sparc_abi_handler_list; p != NULL; p = p->next)
+    {
+      if (p->os_ident == os_ident)
+	{
+	  internal_error
+	    (__FILE__, __LINE__,
+	     "sparc_gdbarch_register_os_abi: A handler for this ABI variant (%d)"
+	     " has already been registered", (int)os_ident);
+	  /* If user wants to continue, override previous definition.  */
+	  p->init_abi = init_abi;
+	  return;
+	}
+    }
+
+  p = (struct sparc_abi_handler *) xmalloc (sizeof (*p));
+  p->os_ident = os_ident;
+  p->init_abi = init_abi;
+  p->next = sparc_abi_handler_list;
+  sparc_abi_handler_list = p;
+}
+
 /*
  * Gdbarch "constructor" function.
  */
@@ -2906,6 +2924,8 @@ sparc_gdbarch_init (struct gdbarch_info 
 {
   struct gdbarch *gdbarch;
   struct gdbarch_tdep *tdep;
+  struct sparc_abi_handler *abi_handler;
+  int os_ident;
 
   static LONGEST call_dummy_32[] = 
     { 0xbc100001, 0x9de38000, 0xbc100002, 0xbe100003,
@@ -2929,10 +2949,33 @@ sparc_gdbarch_init (struct gdbarch_info 
     };
   static LONGEST call_dummy_nil[] = {0};
 
+  if (info.abfd != NULL
+      && bfd_get_flavour (info.abfd) == bfd_target_elf_flavour)
+    {
+      os_ident = elf_elfheader (info.abfd)->e_ident[EI_OSABI];
+
+      /* If os_ident is 0, it is not necessarily the case that we're
+         on a SYSV system.  (ELFOSABI_NONE is defined to be 0.)
+         GNU/Linux uses a note section to record OS/ABI info, but
+         leaves e_ident[EI_OSABI] zero.  So we have to check for note
+         sections too.  */
+      if (os_ident == ELFOSABI_NONE)
+	bfd_map_over_sections (info.abfd,
+			       process_note_abi_tag_sections,
+			       &os_ident);
+    }
+  else
+    os_ident = -1;
+
   /* First see if there is already a gdbarch that can satisfy the request.  */
-  arches = gdbarch_list_lookup_by_info (arches, &info);
-  if (arches != NULL)
-    return arches->gdbarch;
+  for (arches = gdbarch_list_lookup_by_info (arches, &info);
+       arches != NULL;
+       arches = gdbarch_list_lookup_by_info (arches->next, &info))
+    {
+      tdep = gdbarch_tdep (arches->gdbarch);
+      if (tdep && tdep->os_ident == os_ident)
+        return arches->gdbarch;
+    }
 
   /* None found: is the request for a sparc architecture? */
   if (info.bfd_arch_info->arch != bfd_arch_sparc)
@@ -2942,6 +2985,8 @@ sparc_gdbarch_init (struct gdbarch_info 
   tdep = (struct gdbarch_tdep *) xmalloc (sizeof (struct gdbarch_tdep));
   gdbarch = gdbarch_alloc (&info, tdep);
 
+  tdep->os_ident = os_ident;
+
   /* First set settings that are common for all sparc architectures.  */
   set_gdbarch_believe_pcc_promotion (gdbarch, 1);
   set_gdbarch_breakpoint_from_pc (gdbarch, memory_breakpoint_from_pc);
@@ -3212,6 +3257,107 @@ sparc_gdbarch_init (struct gdbarch_info 
       break;
     }
 
+  for (abi_handler = sparc_abi_handler_list;
+       abi_handler;
+       abi_handler = abi_handler->next)
+    if (abi_handler->os_ident == os_ident)
+      break;
+
+  if (abi_handler)
+    abi_handler->init_abi (info, gdbarch);
+
   return gdbarch;
 }
 
+static void
+sparc_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+
+  if (tdep == NULL)
+    return;
+
+  fprintf_unfiltered (file, "sparc_dump_tdep: os_ident ");
+  switch (tdep->os_ident)
+    {
+    case ELFOSABI_NONE:
+      fprintf_unfiltered (file, "ELFOSABI_NONE");
+      break;
+    case ELFOSABI_NETBSD:
+      fprintf_unfiltered (file, "ELFOSABI_NETBSD");
+      break;
+    case ELFOSABI_LINUX:
+      fprintf_unfiltered (file, "ELFOSABI_LINUX");
+      break;
+    case ELFOSABI_HURD:
+      fprintf_unfiltered (file, "ELFOSABI_HURD");
+      break;
+    case ELFOSABI_SOLARIS:
+      fprintf_unfiltered (file, "ELFOSABI_SOLARIS");
+      break;
+    case ELFOSABI_FREEBSD:
+      fprintf_unfiltered (file, "ELFOSABI_FREEBSD");
+      break;
+    case ELFOSABI_OPENBSD:
+      fprintf_unfiltered (file, "ELFOSABI_OPENBSD");
+      break;
+    case ELFOSABI_STANDALONE:
+      fprintf_unfiltered (file, "ELFOSABI_STANDALONE");
+      break;
+    default:
+      fprintf_unfiltered (file, "UNKNOWN");
+      break;
+    }
+
+  fprintf_unfiltered (file, "sparc_dump_tdep: has_fpu %d\n",
+		      tdep->has_fpu);
+  fprintf_unfiltered (file, "sparc_dump_tdep: fp_register_bytes %d\n",
+		      tdep->fp_register_bytes);
+  fprintf_unfiltered (file, "sparc_dump_tdep: y_regnum %d\n",
+		      tdep->y_regnum);
+  fprintf_unfiltered (file, "sparc_dump_tdep: fp_max_regnum %d\n",
+		      tdep->fp_max_regnum);
+  fprintf_unfiltered (file, "sparc_dump_tdep: intreg_size %d\n",
+		      tdep->intreg_size);
+  fprintf_unfiltered (file, "sparc_dump_tdep: reg_save_offset %d\n",
+		      tdep->reg_save_offset);
+  fprintf_unfiltered (file, "sparc_dump_tdep: call_dummy_call_offset %d\n",
+		      tdep->call_dummy_call_offset);
+  fprintf_unfiltered (file, "sparc_dump_tdep: print_insn_mach ");
+  switch (tdep->print_insn_mach)
+    {
+    case bfd_mach_sparc:
+      fprintf_unfiltered (file, "bfd_mach_sparc\n");
+      break;
+    case bfd_mach_sparc_sparclet:
+      fprintf_unfiltered (file, "bfd_mach_sparc_sparclet\n");
+      break;
+    case bfd_mach_sparc_sparclite:
+      fprintf_unfiltered (file, "bfd_mach_sparc_sparclite\n");
+      break;
+    case bfd_mach_sparc_sparclite_le:
+      fprintf_unfiltered (file, "bfd_mach_sparc_sparclite_le\n");
+      break;
+    case bfd_mach_sparc_v8plus:
+      fprintf_unfiltered (file, "bfd_mach_sparc_v8plus\n");
+      break;
+    case bfd_mach_sparc_v8plusa:
+      fprintf_unfiltered (file, "bfd_mach_sparc_v8plusa\n");
+      break;
+    case bfd_mach_sparc_v8plusb:
+      fprintf_unfiltered (file, "bfd_mach_sparc_v8plusb\n");
+      break;
+    case bfd_mach_sparc_v9:
+      fprintf_unfiltered (file, "bfd_mach_sparc_v9\n");
+      break;
+    case bfd_mach_sparc_v9a:
+      fprintf_unfiltered (file, "bfd_mach_sparc_v9a\n");
+      break;
+    case bfd_mach_sparc_v9b:
+      fprintf_unfiltered (file, "bfd_mach_sparc_v9b\n");
+      break;
+    default:
+      fprintf_unfiltered (file, "UNKNOWN\n");
+      break;
+    };
+}
--- ./sparc-tdep.h.~1~	Sat Apr 20 20:24:22 2002
+++ ./sparc-tdep.h	Sat Apr 20 20:23:31 2002
@@ -0,0 +1,99 @@
+/* Common target dependent code for GDB on SPARC systems.
+   Copyright 2002 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/*
+ * Some local macros that have multi-arch and non-multi-arch versions:
+ */
+
+#if (GDB_MULTI_ARCH > 0)
+
+/* Does the target have Floating Point registers?  */
+#define SPARC_HAS_FPU     (gdbarch_tdep (current_gdbarch)->has_fpu)
+/* Number of bytes devoted to Floating Point registers: */
+#define FP_REGISTER_BYTES (gdbarch_tdep (current_gdbarch)->fp_register_bytes)
+/* Highest numbered Floating Point register.  */
+#define FP_MAX_REGNUM     (gdbarch_tdep (current_gdbarch)->fp_max_regnum)
+/* Size of a general (integer) register: */
+#define SPARC_INTREG_SIZE (gdbarch_tdep (current_gdbarch)->intreg_size)
+/* Offset within the call dummy stack of the saved registers.  */
+#define DUMMY_REG_SAVE_OFFSET (gdbarch_tdep (current_gdbarch)->reg_save_offset)
+
+#else /* non-multi-arch */
+
+/* Does the target have Floating Point registers?  */
+#if defined(TARGET_SPARCLET) || defined(TARGET_SPARCLITE)
+#define SPARC_HAS_FPU 0
+#else
+#define SPARC_HAS_FPU 1
+#endif
+
+/* Number of bytes devoted to Floating Point registers: */
+#if (GDB_TARGET_IS_SPARC64)
+#define FP_REGISTER_BYTES (64 * 4)
+#else
+#if (SPARC_HAS_FPU)
+#define FP_REGISTER_BYTES (32 * 4)
+#else
+#define FP_REGISTER_BYTES 0
+#endif
+#endif
+
+/* Highest numbered Floating Point register.  */
+#if (GDB_TARGET_IS_SPARC64)
+#define FP_MAX_REGNUM (FP0_REGNUM + 48)
+#else
+#define FP_MAX_REGNUM (FP0_REGNUM + 32)
+#endif
+
+/* Size of a general (integer) register: */
+#define SPARC_INTREG_SIZE (REGISTER_RAW_SIZE (G0_REGNUM))
+
+/* Offset within the call dummy stack of the saved registers.  */
+#if (GDB_TARGET_IS_SPARC64)
+#define DUMMY_REG_SAVE_OFFSET (128 + 16)
+#else
+#define DUMMY_REG_SAVE_OFFSET 0x60
+#endif
+
+#endif /* GDB_MULTI_ARCH */
+
+#ifndef CALL_DUMMY_CALL_OFFSET
+#define CALL_DUMMY_CALL_OFFSET \
+     (gdbarch_tdep (current_gdbarch)->call_dummy_call_offset)
+#endif /* CALL_DUMMY_CALL_OFFSET */
+
+struct gdbarch_tdep
+  {
+    int os_ident;
+    int has_fpu;
+    int fp_register_bytes;
+    int y_regnum;
+    int fp_max_regnum;
+    int intreg_size;
+    int reg_save_offset;
+    int call_dummy_call_offset;
+    int print_insn_mach;
+  };
+
+/* How a OS variant tells the SPARC generic code that it can handle an ABI
+   type.  */
+extern void sparc_gdbarch_register_os_abi (int os_ident,
+					   void (*init_abi)(struct gdbarch_info,
+							    struct gdbarch *));