deal with endian-ness in mach-o non-scattered relocs.

BFD:

	* mach-o.c (bfd_mach_o_swap_in_non_scattered_reloc): New.
	(bfd_mach_o_canonicalize_one_reloc):  Swap non-scattered reloc
	bit-fields when target and host differ in endian-ness.  When
	PAIRs are non-scattered	find the 'symbol' from the preceding
	reloc.  Add FIXME re. reloc symbols on section boundaries.
	(bfd_mach_o_swap_out_non_scattered_reloc): New.
	(bfd_mach_o_write_relocs): Use bfd_mach_o_encode_non_scattered_reloc.

include/mach-o:

	* external.h: Add comments about relocations fields.  Add macros
	for non-scattered relocations.  Move scattered relocation macros to here.
	* reloc.h: Remove macros related to external representation of reloc fields.

3 files changed, 48 insertions, 21 deletions

diff --git a/include/mach-o/ChangeLog b/include/mach-o/ChangeLog
index ab3cc6828..19eacd0c5 100644
--- a/include/mach-o/ChangeLog
+++ b/include/mach-o/ChangeLog
@@ -1,3 +1,11 @@
+2012-02-23  Iain Sandoe  <idsandoe@googlemail.com>
+
+	* external.h: Add comments about relocations fields.  Add macros
+	for non-scattered relocations.  Move scattered relocation macros to
+	here.
+	* reloc.h: Remove macros related to external representation of reloc
+	fields.
+
 2012-01-12  Iain Sandoe  <idsandoe@googlemail.com>
 
 	* loader.h (BFD_MACH_O_INDIRECT_SYM_LOCAL): New.
diff --git a/include/mach-o/external.h b/include/mach-o/external.h
index ad419ef54..41a293250 100644
--- a/include/mach-o/external.h
+++ b/include/mach-o/external.h
@@ -116,6 +116,45 @@ struct mach_o_reloc_info_external
 };
 #define BFD_MACH_O_RELENT_SIZE 8
 
+/* Relocations are based on 'address' being a section offset and an assumption
+   that sections are never more than 2^24-1 bytes in size.  Relocation data
+   also carry information on type/size/PC-relative/extern and whether scattered
+   or not [stored in the MSB of the r_address].  */
+
+#define BFD_MACH_O_SR_SCATTERED		0x80000000
+
+/* For a non-scattered reloc, the relocation info is found in r_symbolnum.
+   Bytes 1 to 3 contain the symbol number (0xffffff, in a non-scattered PAIR).  
+   Byte 4 contains the relocation info - but with differing bit-positions
+   dependent on target endian-ness - as below.  */
+
+#define BFD_MACH_O_LE_PCREL		0x01
+#define BFD_MACH_O_LE_LENGTH_SHIFT	1
+#define BFD_MACH_O_LE_EXTERN		0x08
+#define BFD_MACH_O_LE_TYPE_SHIFT	4
+
+#define BFD_MACH_O_BE_PCREL		0x80
+#define BFD_MACH_O_BE_LENGTH_SHIFT	5
+#define BFD_MACH_O_BE_EXTERN		0x10
+#define BFD_MACH_O_BE_TYPE_SHIFT	0
+
+/* The field sizes are the same for both BE and LE.  */
+#define BFD_MACH_O_LENGTH_MASK		0x03
+#define BFD_MACH_O_TYPE_MASK		0x0f
+
+/* For a scattered reloc entry the info is contained in r_address.  There
+   is no need to discriminate on target endian-ness, since the design was
+   arranged to produce the same layout on both.  Scattered relocations are
+   only used for local items, therefore there is no 'extern' field.  */
+
+#define BFD_MACH_O_SR_PCREL		0x40000000
+#define BFD_MACH_O_GET_SR_LENGTH(s)	(((s) >> 28) & 0x3)
+#define BFD_MACH_O_GET_SR_TYPE(s)	(((s) >> 24) & 0x0f)
+#define BFD_MACH_O_GET_SR_ADDRESS(s)	((s) & 0x00ffffff)
+#define BFD_MACH_O_SET_SR_LENGTH(l)	(((l) & 0x3) << 28)
+#define BFD_MACH_O_SET_SR_TYPE(t)	(((t) & 0xf) << 24)
+#define BFD_MACH_O_SET_SR_ADDRESS(s)	((s) & 0x00ffffff)
+
 struct mach_o_symtab_command_external
 {
   unsigned char symoff[4];	/* File offset of the symbol table.  */
diff --git a/include/mach-o/reloc.h b/include/mach-o/reloc.h
index 93ebb8b5f..bab31efeb 100644
--- a/include/mach-o/reloc.h
+++ b/include/mach-o/reloc.h
@@ -1,5 +1,5 @@
 /* Mach-O support for BFD.
-   Copyright 2011
+   Copyright 2011, 2012
    Free Software Foundation, Inc.
 
    This file is part of BFD, the Binary File Descriptor library.
@@ -22,26 +22,6 @@
 #ifndef _MACH_O_RELOC_H
 #define _MACH_O_RELOC_H
 
-/* Fields for a normal (non-scattered) entry.  */
-#define BFD_MACH_O_R_PCREL		0x01000000
-#define BFD_MACH_O_GET_R_LENGTH(s)	(((s) >> 25) & 0x3)
-#define BFD_MACH_O_R_EXTERN		0x08000000
-#define BFD_MACH_O_GET_R_TYPE(s)	(((s) >> 28) & 0x0f)
-#define BFD_MACH_O_GET_R_SYMBOLNUM(s)	((s) & 0x00ffffff)
-#define BFD_MACH_O_SET_R_LENGTH(l)	(((l) & 0x3) << 25)
-#define BFD_MACH_O_SET_R_TYPE(t)	(((t) & 0xf) << 28)
-#define BFD_MACH_O_SET_R_SYMBOLNUM(s)	((s) & 0x00ffffff)
-
-/* Fields for a scattered entry.  */
-#define BFD_MACH_O_SR_SCATTERED		0x80000000
-#define BFD_MACH_O_SR_PCREL		0x40000000
-#define BFD_MACH_O_GET_SR_LENGTH(s)	(((s) >> 28) & 0x3)
-#define BFD_MACH_O_GET_SR_TYPE(s)	(((s) >> 24) & 0x0f)
-#define BFD_MACH_O_GET_SR_ADDRESS(s)	((s) & 0x00ffffff)
-#define BFD_MACH_O_SET_SR_LENGTH(l)	(((l) & 0x3) << 28)
-#define BFD_MACH_O_SET_SR_TYPE(t)	(((t) & 0xf) << 24)
-#define BFD_MACH_O_SET_SR_ADDRESS(s)	((s) & 0x00ffffff)
-
 /* Generic relocation types (used by i386).  */
 #define BFD_MACH_O_GENERIC_RELOC_VANILLA 	0
 #define BFD_MACH_O_GENERIC_RELOC_PAIR	 	1