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[PATCH, needs GWP] Add a BSF_SYNTHETIC flag

Richard Sandiford rdsandiford@googlemail.com
Sat Jun 28 17:07:00 GMT 2008 
BFD sometimes creates "synthetic" symbols to make disassembled code
easier to understand.  For example, it can create a "foo@plt" symbol
for foo's PLT entry.  These synthetic symbols do not have the full ELF
information, so it is not safe to assume that every symbol in an
ELF section has elf_symbol_type.

This patch fixes one such assumption in the MIPS disassembler.
It relies on a new BSF for synthetic symbols.

Tested on mips64-linux-gnu and mips64el-linux-gnu.  OK to install?

Richard


bfd/
	* syms.c (BSF_SYNTHETIC): New flag.
	* elf.c (_bfd_elf_get_synthetic_symtab): Set it.
	* bfd-in.h (bfd_asymbol_flavour): Return bfd_target_unknown_flavour
	for synthetic symbols.
	* bfd-in2.h: Regenerate.

opcodes/
	* mips-dis.c (_print_insn_mips): Use bfd_asymbol_flavour to check
	for ELF symbols.  Fix aliasing violation.

Index: bfd/syms.c
===================================================================
--- bfd/syms.c	2008-06-28 17:09:08.000000000 +0100
+++ bfd/syms.c	2008-06-28 17:14:51.000000000 +0100
@@ -297,6 +297,9 @@ typedef asymbol, symbol handling functio
 .     with the expression tree serialized in the symbol name.  *}
 .#define BSF_SRELC 0x100000
 .
+.  {* This symbol was created by bfd_get_synthetic_symtab.  *}
+.#define BSF_SYNTHETIC 0x200000
+.
 .  flagword flags;
 .
 .  {* A pointer to the section to which this symbol is
Index: bfd/elf.c
===================================================================
--- bfd/elf.c	2008-06-28 17:09:08.000000000 +0100
+++ bfd/elf.c	2008-06-28 17:14:51.000000000 +0100
@@ -8786,6 +8786,7 @@ _bfd_elf_get_synthetic_symtab (bfd *abfd
 	 we are defining a symbol, ensure one of them is set.  */
       if ((s->flags & BSF_LOCAL) == 0)
 	s->flags |= BSF_GLOBAL;
+      s->flags |= BSF_SYNTHETIC;
       s->section = plt;
       s->value = addr - plt->vma;
       s->name = names;
Index: bfd/bfd-in.h
===================================================================
--- bfd/bfd-in.h	2008-06-28 17:09:08.000000000 +0100
+++ bfd/bfd-in.h	2008-06-28 17:14:51.000000000 +0100
@@ -231,7 +231,10 @@ #define bfd_asymbol_value(x) (bfd_asymbo
 #define bfd_asymbol_name(x) ((x)->name)
 /*Perhaps future: #define bfd_asymbol_bfd(x) ((x)->section->owner)*/
 #define bfd_asymbol_bfd(x) ((x)->the_bfd)
-#define bfd_asymbol_flavour(x) (bfd_asymbol_bfd(x)->xvec->flavour)
+#define bfd_asymbol_flavour(x)			\
+  (((x)->flags & BSF_SYNTHETIC) != 0		\
+   ? bfd_target_unknown_flavour			\
+   : bfd_asymbol_bfd (x)->xvec->flavour)
 
 /* A canonical archive symbol.  */
 /* This is a type pun with struct ranlib on purpose!  */
Index: opcodes/mips-dis.c
===================================================================
--- opcodes/mips-dis.c	2008-06-28 17:14:12.000000000 +0100
+++ opcodes/mips-dis.c	2008-06-28 17:14:51.000000000 +0100
@@ -2039,8 +2039,8 @@ _print_insn_mips (bfd_vma memaddr,
 
 #if SYMTAB_AVAILABLE
   if (info->mach == bfd_mach_mips16
-      || (info->flavour == bfd_target_elf_flavour
-	  && info->symbols != NULL
+      || (info->symbols != NULL
+	  && bfd_asymbol_flavour (*info->symbols) == bfd_target_elf_flavour
 	  && ELF_ST_IS_MIPS16 ((*(elf_symbol_type **) info->symbols)
 			       ->internal_elf_sym.st_other)))
     return print_insn_mips16 (memaddr, info);
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