Re: [PATCH] ARM Disassembler fix

[Daniel Gutson <dgutson at codesourcery dot com>]

Hi Pedro,

Pedro Alves wrote:
> On Monday 04 January 2010 20:43:29, Daniel Gutson wrote:
> > Hi Nick,
> >
> > Nick Clifton wrote:
> > > Hi Daniel,
> > >
> > > > The attached patch fixes a bug that causes the disassembler to dump 
> > > > code when it should dump data.
> > > This looks wrong to me.  Why should the disassembler assume that, in the 
> > > absence of mapping symbols to guide it, the .text section contains data 
> > > rather than instructions ?  Surely it is more likely to contain 
> > > instructions and it is merely that the mapping symbols are absent ?
>
> > Please refer to the AAELF, i.e. IHI0044D pp 23, @4.6.5.1, e.g.
> > "A section must have a mapping symbol defined at the beginning of the 
> > section; however, if the section contains only data then the mapping 
> > symbol may be omitted."
>
> The patch breaks text disassembly on arm non-elf targets.  Could
> this be restrict to elf, please?

I now restricted the value initialization of is_data depending on the 
obj flavour.

ChangeLog is the same.

Please let me know how does this look now.

Thanks!
	Daniel.


--
Daniel Gutson
CodeSourcery
www.codesourcery.com

Index: gas/testsuite/gas/arm/dis-data.d
===================================================================
RCS file: gas/testsuite/gas/arm/dis-data.d
diff -N gas/testsuite/gas/arm/dis-data.d
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ gas/testsuite/gas/arm/dis-data.d	5 Jan 2010 22:12:56 -0000
@@ -0,0 +1,9 @@
+# name: Data disassembler test 
+# objdump: -dr --prefix-addresses --show-raw-insn
+
+.*: +file format .*arm.*
+
+Disassembly of section \.text:
+0x00000000 20010000 	.word	0x20010000
+0x00000004 000000f9 	.word	0x000000f9
+0x00000008 00004cd5 	.word	0x00004cd5
Index: gas/testsuite/gas/arm/dis-data.s
===================================================================
RCS file: gas/testsuite/gas/arm/dis-data.s
diff -N gas/testsuite/gas/arm/dis-data.s
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ gas/testsuite/gas/arm/dis-data.s	5 Jan 2010 22:12:56 -0000
@@ -0,0 +1,5 @@
+.syntax unified
+.word	0x20010000
+.word	0x000000f9
+.word	0x00004cd5
+
Index: opcodes/arm-dis.c
===================================================================
RCS file: /cvs/src/src/opcodes/arm-dis.c,v
retrieving revision 1.120
diff -u -p -r1.120 arm-dis.c
--- opcodes/arm-dis.c	4 Jan 2010 10:18:32 -0000	1.120
+++ opcodes/arm-dis.c	5 Jan 2010 22:12:57 -0000
@@ -4355,7 +4355,8 @@ print_insn (bfd_vma pc, struct disassemb
   long		given;
   int           status;
   int           is_thumb = FALSE;
-  int           is_data = FALSE;
+  int           is_data = (bfd_asymbol_flavour (*info->symtab)
+			   == bfd_target_elf_flavour) ? TRUE : FALSE;
   int           little_code;
   unsigned int	size = 4;
   void	 	(*printer) (bfd_vma, struct disassemble_info *, long);
@@ -4415,7 +4416,7 @@ print_insn (bfd_vma pc, struct disassemb
       bfd_vma addr;
       int n;
       int last_sym = -1;
-      enum map_type type = MAP_ARM;
+      enum map_type type = MAP_DATA;
 
       if (pc <= last_mapping_addr)
 	last_mapping_sym = -1;
@@ -4478,7 +4479,9 @@ print_insn (bfd_vma pc, struct disassemb
 	  for (n = last_sym + 1; n < info->symtab_size; n++)
 	    {
 	      addr = bfd_asymbol_value (info->symtab[n]);
-	      if (addr > pc)
+	      if (addr > pc
+		  && (info->section == NULL
+		      || info->section == info->symtab[n]->section))
 		{
 		  if (addr - pc < size)
 		    size = addr - pc;