* libelf.h: Added some comments.

	(struct elf_backend_data): Added elf_backend_ecoff_debug_swap
	field.  Removed unused write_relocs field.
	* elf32-target.h: Adjusted elf_backend_data initialization
	accordingly.
	* elf64-target.h: Corrected elf_backend_data initialization to
	fill in all fields and to set elf_64_p to 1.

4 files changed, 114 insertions, 15 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index d0a7f59..0cc7410 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,13 @@
+Tue Nov  9 11:26:05 1993  Ian Lance Taylor  (ian@tweedledumb.cygnus.com)
+
+	* libelf.h: Added some comments.
+	(struct elf_backend_data): Added elf_backend_ecoff_debug_swap
+	field.  Removed unused write_relocs field.
+	* elf32-target.h: Adjusted elf_backend_data initialization
+	accordingly.
+	* elf64-target.h: Corrected elf_backend_data initialization to
+	fill in all fields and to set elf_64_p to 1.
+
 Mon Nov  8 18:13:14 1993  Ian Lance Taylor  (ian@tweedledumb.cygnus.com)
 
 	* elfcode.h (bfd_section_from_shdr): Remove duplicate assignment
diff --git a/bfd/elf32-target.h b/bfd/elf32-target.h
index 8d0076b..9b1c832 100644
--- a/bfd/elf32-target.h
+++ b/bfd/elf32-target.h
@@ -79,6 +79,9 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 #ifndef elf_backend_section_from_bfd_section
 #define elf_backend_section_from_bfd_section	0	/* elf_backend_section_from_bfd_section */
 #endif
+#ifndef elf_backend_ecoff_debug_swap
+#define elf_backend_ecoff_debug_swap	0	/* elf_backed_ecoff_debug_swap */
+#endif
 
 static CONST struct elf_backend_data elf32_bed =
 {
@@ -89,16 +92,16 @@ static CONST struct elf_backend_data elf32_bed =
 #endif
   0,				/* elf_64_p */
   ELF_ARCH,			/* arch */
+  ELF_MAXPAGESIZE,		/* maxpagesize */
   elf_info_to_howto,		/* elf_info_to_howto */
   elf_info_to_howto_rel,	/* elf_info_to_howto_rel */
-  ELF_MAXPAGESIZE,		/* maxpagesize */
-  bfd_elf32__write_relocs,	/* write_relocs */
   elf_backend_symbol_processing,	/* elf_backend_symbol_processing */
   elf_backend_symbol_table_processing,	/* elf_backend_symbol_table_processing */
   elf_backend_section_processing,	/* elf_backend_section_processing */
   elf_backend_section_from_shdr,	/* elf_backend_section_from_shdr */
   elf_backend_fake_sections,		/* elf_backend_fake_sections */
   elf_backend_section_from_bfd_section,	/* elf_backend_section_from_bfd_section */
+  elf_backend_ecoff_debug_swap		/* elf_backend_ecoff_debug_swap */
 };
 
 #ifdef TARGET_BIG_SYM
diff --git a/bfd/elf64-target.h b/bfd/elf64-target.h
index d7ee425..790e4a6 100644
--- a/bfd/elf64-target.h
+++ b/bfd/elf64-target.h
@@ -59,6 +59,28 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 #define ELF_MAXPAGESIZE 1
 #endif
 
+#ifndef elf_backend_symbol_processing
+#define elf_backend_symbol_processing	0	/* elf_backend_symbol_processing */
+#endif
+#ifndef elf_backend_symbol_table_processing
+#define elf_backend_symbol_table_processing	0	/* elf_backend_symbol_table_processing */
+#endif
+#ifndef elf_backend_section_processing
+#define elf_backend_section_processing	0	/* elf_backend_section_processing */
+#endif
+#ifndef elf_backend_section_from_shdr
+#define elf_backend_section_from_shdr	0	/* elf_backend_section_from_shdr */
+#endif
+#ifndef elf_backend_fake_sections
+#define elf_backend_fake_sections	0	/* elf_backend_fake_sections */
+#endif
+#ifndef elf_backend_section_from_bfd_section
+#define elf_backend_section_from_bfd_section	0	/* elf_backend_section_from_bfd_section */
+#endif
+#ifndef elf_backend_ecoff_debug_swap
+#define elf_backend_ecoff_debug_swap	0	/* elf_backed_ecoff_debug_swap */
+#endif
+
 static CONST struct elf_backend_data elf64_bed =
 {
 #ifdef USE_REL
@@ -66,15 +88,18 @@ static CONST struct elf_backend_data elf64_bed =
 #else
   1,				/* use_rela_p */
 #endif
-  0,				/* elf_64_p */
+  1,				/* elf_64_p */
   ELF_ARCH,			/* arch */
+  ELF_MAXPAGESIZE,		/* maxpagesize */
   elf_info_to_howto,		/* elf_info_to_howto */
-#ifdef elf_info_to_howto_rel
   elf_info_to_howto_rel,	/* elf_info_to_howto_rel */
-#else
-  0,				/* elf_info_to_howto_rel */
-#endif
-  ELF_MAXPAGESIZE,		/* maxpagesize */
+  elf_backend_symbol_processing,	/* elf_backend_symbol_processing */
+  elf_backend_symbol_table_processing,	/* elf_backend_symbol_table_processing */
+  elf_backend_section_processing,	/* elf_backend_section_processing */
+  elf_backend_section_from_shdr,	/* elf_backend_section_from_shdr */
+  elf_backend_fake_sections,		/* elf_backend_fake_sections */
+  elf_backend_section_from_bfd_section,	/* elf_backend_section_from_bfd_section */
+  elf_backend_ecoff_debug_swap		/* elf_backend_ecoff_debug_swap */
 };
 
 #ifdef TARGET_BIG_SYM
diff --git a/bfd/libelf.h b/bfd/libelf.h
index 187c51a..2c0969a 100644
--- a/bfd/libelf.h
+++ b/bfd/libelf.h
@@ -42,10 +42,18 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 #define ElfNAME(X)	NAME(Elf,X)
 #define elfNAME(X)	NAME(elf,X)
 
+/* Information held for an ELF symbol.  The first field is the
+   corresponding asymbol.  Every symbol is an ELF file is actually a
+   pointer to this structure, although it is often handled as a
+   pointer to an asymbol.  */
+
 typedef struct
 {
+  /* The BFD symbol.  */
   asymbol symbol;
+  /* ELF symbol information.  */
   Elf_Internal_Sym internal_elf_sym;
+  /* Backend specific information.  */
   union
     {
       unsigned int hppa_arg_reloc;
@@ -54,24 +62,77 @@ typedef struct
   tc_data;
 } elf_symbol_type;
 
+/* Constant information held for an ELF backend.  */
+
 struct elf_backend_data
 {
+  /* Whether the backend uses REL or RELA relocations.  FIXME: some
+     ELF backends use both.  When we need to support one, this whole
+     approach will need to be changed.  */
   int use_rela_p;
+
+  /* Whether this backend is 64 bits or not.  FIXME: Who cares?  */
   int elf_64_p;
+
+  /* The architecture for this backend.  */
   enum bfd_architecture arch;
+
+  /* The maximum page size for this backend.  */
+  bfd_vma maxpagesize;
+
+  /* A function to translate an ELF RELA relocation to a BFD arelent
+     structure.  */
   void (*elf_info_to_howto) PARAMS ((bfd *, arelent *,
 				     Elf_Internal_Rela *));
+
+  /* A function to translate an ELF REL relocation to a BFD arelent
+     structure.  */
   void (*elf_info_to_howto_rel) PARAMS ((bfd *, arelent *,
 					 Elf_Internal_Rel *));
-  bfd_vma maxpagesize;
-  void (*write_relocs) PARAMS ((bfd *, asection *, PTR));
 
+  /* The remaining functions are hooks which are called only if they
+     are not NULL.  */
+
+  /* A function to do additional symbol processing when reading the
+     ELF symbol table.  This is where any processor-specific special
+     section indices are handled.  */
   void (*elf_backend_symbol_processing) PARAMS ((bfd *, asymbol *));
-  boolean (*elf_backend_symbol_table_processing) PARAMS ((bfd *, elf_symbol_type *, int));
-  boolean (*elf_backend_section_processing) PARAMS ((bfd *, Elf32_Internal_Shdr *));
-  boolean (*elf_backend_section_from_shdr) PARAMS ((bfd *, Elf32_Internal_Shdr *, char *));
-  boolean (*elf_backend_fake_sections) PARAMS ((bfd *, Elf32_Internal_Shdr *, asection *));
-  boolean (*elf_backend_section_from_bfd_section) PARAMS ((bfd *, Elf32_Internal_Shdr *, asection *, int *));
+
+  /* A function to do additional symbol processing after reading the
+     entire ELF symbol table.  */
+  boolean (*elf_backend_symbol_table_processing) PARAMS ((bfd *,
+							  elf_symbol_type *,
+							  int));
+
+  /* A function to do additional processing on the ELF section header
+     just before writing it out.  This is used to set the flags and
+     type fields for some sections, or to actually write out data for
+     unusual sections.  */
+  boolean (*elf_backend_section_processing) PARAMS ((bfd *,
+						     Elf32_Internal_Shdr *));
+
+  /* A function to handle unusual section types when creating BFD
+     sections from ELF sections.  */
+  boolean (*elf_backend_section_from_shdr) PARAMS ((bfd *,
+						    Elf32_Internal_Shdr *,
+						    char *));
+
+  /* A function to set up the ELF section header for a BFD section in
+     preparation for writing it out.  This is where the flags and type
+     fields are set for unusual sections.  */
+  boolean (*elf_backend_fake_sections) PARAMS ((bfd *, Elf32_Internal_Shdr *,
+						asection *));
+
+  /* A function to get the ELF section index for a BFD section.  If
+     this returns true, the section was found.  If it is a normal ELF
+     section, *RETVAL should be left unchanged.  If it is not a normal
+     ELF section *RETVAL should be set to the SHN_xxxx index.  */
+  boolean (*elf_backend_section_from_bfd_section)
+    PARAMS ((bfd *, Elf32_Internal_Shdr *, asection *, int *retval));
+
+  /* The swapping table to use when dealing with ECOFF information.
+     Used for the MIPS ELF .mdebug section.  */
+  const struct ecoff_debug_swap *elf_backend_ecoff_debug_swap;
 };
 
 struct elf_sym_extra