[patch] R_ARM_REL32 and Thumb functions.

[patch] R_ARM_REL32 and Thumb functions.

[Paul Brook]

[-- Attachment #1: Type: text/plain, Size: 1460 bytes --]

The attached patch makes the R_ARM_REL32 relocation set the low bit of the 
value when the relocated symbol is a Thumb function, as required by the ARM 
EABI.

I don't know if the current behavior is considered a bug or a feature for 
pre-EABI objects. For now I'm assuming bug, and making the change 
unconditionally. I can preserver the old behavior if anything depends on it.

A slight complication is that gas will try and fold relative expressions at 
assembly time. This folding is done in generic code, so gets the value wrong. 
e.g.

.thumb_func
foo:
.word foo - .

Will be folded to zero by gas/expr.c:expr.  I've [ab]used md_optimize_expr to 
prevent this happening.

Initially I disabled the folding if either symbol was a Thumb function. 
However this ends up breaking the explicit cfi directives in libgcc, so I've 
only disabled the folding when the first symbol is a Thumb function.

Tested with cross to arm-eabi.
Ok?

Paul

2006-04-20  Paul Brook  <paul@codesourcery.com>

bfd/
	* elf32-arm.c (elf32_arm_final_link_relocate): Set thumb funciton bit
	for R_ARM_REL32.
gas/
	* config/tc-arm.c (arm_optimize_expr): New function.
	(md_apply_fix): Set thumb funciton bit for PC-relative relocations.
	* config/tc-arm.c (md_optimize_expr): Define
	(arm_optimize_expr): Add prototype.
	(TC_FORCE_RELOCATION_SUB_SAME): Define.
ld/testsuite/
	* ld-arm/arm-elf.exp: Add thumb-rel32.
	* ld-arm/thumb-rel32.d: New test.
	* ld-arm/thumb-rel32.s: New test.

[-- Attachment #2: patch.rel32 --]
[-- Type: text/x-diff, Size: 5142 bytes --]

Index: bfd/elf32-arm.c
===================================================================
RCS file: /var/cvsroot/src-cvs/src/bfd/elf32-arm.c,v
retrieving revision 1.70
diff -u -p -r1.70 elf32-arm.c
--- bfd/elf32-arm.c	16 Mar 2006 12:20:15 -0000	1.70
+++ bfd/elf32-arm.c	20 Apr 2006 14:39:04 -0000
@@ -3277,6 +3277,8 @@ elf32_arm_final_link_relocate (reloc_how
 	  value -= (input_section->output_section->vma
 		    + input_section->output_offset + rel->r_offset);
 	  value += addend;
+	  if (sym_flags == STT_ARM_TFUNC)
+	    value |= 1;
 	  break;
 
 	case R_ARM_PREL31:
Index: gas/config/tc-arm.c
===================================================================
RCS file: /var/cvsroot/src-cvs/src/gas/config/tc-arm.c,v
retrieving revision 1.256
diff -u -p -r1.256 tc-arm.c
--- gas/config/tc-arm.c	7 Apr 2006 15:11:19 -0000	1.256
+++ gas/config/tc-arm.c	20 Apr 2006 17:31:47 -0000
@@ -11491,6 +11491,29 @@ get_thumb32_insn (char * buf)
   return insn;
 }
 
+
+/* We usually want to set the low bit on the address of thumb function
+   symbols.  In particular .word foo - . should have the low bit set.
+   Generic code tries to fold the difference of two symbols to
+   a constant.  Prevent this and force a relocation when the first symbols
+   is a thumb function.  */
+int
+arm_optimize_expr (expressionS *l, operatorT op, expressionS *r)
+{
+  if (op == O_subtract
+      && l->X_op == O_symbol
+      && r->X_op == O_symbol
+      && THUMB_IS_FUNC (l->X_add_symbol))
+    {
+      l->X_op = O_subtract;
+      l->X_op_symbol = r->X_add_symbol;
+      l->X_add_number -= r->X_add_number;
+      return 1;
+    }
+  /* Process as normal.  */
+  return 0;
+}
+
 void
 md_apply_fix (fixS *	fixP,
 	       valueT * valP,
@@ -12106,7 +12129,14 @@ md_apply_fix (fixS *	fixP,
     case BFD_RELOC_ARM_TARGET1:
     case BFD_RELOC_ARM_ROSEGREL32:
     case BFD_RELOC_ARM_SBREL32:
+      if (fixP->fx_done || !seg->use_rela_p)
+	md_number_to_chars (buf, value, 4);
+      break;
+
     case BFD_RELOC_32_PCREL:
+      /* Set the low bit of the value if the target is a thumb function.  */
+      if (fixP->fx_done && fixP->fx_addsy && THUMB_IS_FUNC(fixP->fx_addsy))
+	value |= 1;
       if (fixP->fx_done || !seg->use_rela_p)
 	md_number_to_chars (buf, value, 4);
       break;
Index: gas/config/tc-arm.h
===================================================================
RCS file: /var/cvsroot/src-cvs/src/gas/config/tc-arm.h,v
retrieving revision 1.36
diff -u -p -r1.36 tc-arm.h
--- gas/config/tc-arm.h	8 Oct 2005 17:07:16 -0000	1.36
+++ gas/config/tc-arm.h	20 Apr 2006 17:58:59 -0000
@@ -83,6 +83,9 @@ struct fix;
   arm_relax_frag(segment, fragp, stretch)
 extern int arm_relax_frag (asection *, struct frag *, long);
 
+#define md_optimize_expr(l,o,r)		arm_optimize_expr (l, o, r)
+extern int arm_optimize_expr (expressionS *, operatorT, expressionS *);
+
 #define md_cleanup() arm_cleanup ()
 
 #define md_start_line_hook() arm_start_line_hook ()
@@ -148,6 +151,12 @@ extern void arm_md_end (void);
    || (FIX)->fx_r_type == BFD_RELOC_32			\
    || TC_FORCE_RELOCATION (FIX))
 
+/* Force output of R_ARM_REL32 relocations against thumb function symbols.
+   This is needed to ensure the low bit is handled correctly.  */
+#define TC_FORCE_RELOCATION_SUB_SAME(FIX, SEG)	\
+  (THUMB_IS_FUNC ((FIX)->fx_addsy)		\
+   || !SEG_NORMAL (SEG))
+
 #define TC_CONS_FIX_NEW cons_fix_new_arm
 
 #define MAX_MEM_FOR_RS_ALIGN_CODE 31
Index: ld/testsuite/ld-arm/arm-elf.exp
===================================================================
RCS file: /var/cvsroot/src-cvs/src/ld/testsuite/ld-arm/arm-elf.exp,v
retrieving revision 1.11
diff -u -p -r1.11 arm-elf.exp
--- ld/testsuite/ld-arm/arm-elf.exp	7 Mar 2006 08:39:21 -0000	1.11
+++ ld/testsuite/ld-arm/arm-elf.exp	20 Apr 2006 14:47:23 -0000
@@ -119,6 +119,9 @@ set armelftests {
     {"Thumb entry point" "-T arm.ld" "" {thumb-entry.s}
      {{readelf -h thumb-entry.d}}
      "thumb-entry"}
+    {"thumb-rel32" "-static -T arm.ld" "" {thumb-rel32.s}
+     {{objdump -s thumb-rel32.d}}
+     "thumb-rel32"}
 }
 
 run_ld_link_tests $armelftests
Index: ld/testsuite/ld-arm/thumb-rel32.d
===================================================================
RCS file: ld/testsuite/ld-arm/thumb-rel32.d
diff -N ld/testsuite/ld-arm/thumb-rel32.d
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ ld/testsuite/ld-arm/thumb-rel32.d	20 Apr 2006 14:45:39 -0000
@@ -0,0 +1,7 @@
+
+.*:     file format.*
+
+Contents of section .text:
+ 8000 (00000009 fffffffd|09000000 fdffffff) .*
+# Ignore .ARM.attributes section
+#...
Index: ld/testsuite/ld-arm/thumb-rel32.s
===================================================================
RCS file: ld/testsuite/ld-arm/thumb-rel32.s
diff -N ld/testsuite/ld-arm/thumb-rel32.s
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ ld/testsuite/ld-arm/thumb-rel32.s	20 Apr 2006 16:36:07 -0000
@@ -0,0 +1,15 @@
+	.text
+	.arch armv4t
+	.global	_start
+	.type	_start, %function
+	.thumb_func
+_start:
+	.word bar - .
+	.word _start - .
+	.section .after, "ax", %progbits
+	.global bar
+	.type bar, %function
+	.thumb_func
+bar:
+	.word 0
+	.ident	"GCC: (GNU) 4.1.0 (CodeSourcery ARM)"

Re: [patch] R_ARM_REL32 and Thumb functions.

[Daniel Jacobowitz]

On Thu, Apr 20, 2006 at 07:29:49PM +0100, Paul Brook wrote:
> The attached patch makes the R_ARM_REL32 relocation set the low bit of the 
> value when the relocated symbol is a Thumb function, as required by the ARM 
> EABI.
> 
> I don't know if the current behavior is considered a bug or a feature for 
> pre-EABI objects. For now I'm assuming bug, and making the change 
> unconditionally. I can preserver the old behavior if anything depends on it.
> 
> A slight complication is that gas will try and fold relative expressions at 
> assembly time. This folding is done in generic code, so gets the value wrong. 
> e.g.
> 
> .thumb_func
> foo:
> .word foo - .
> 
> Will be folded to zero by gas/expr.c:expr.  I've [ab]used md_optimize_expr to 
> prevent this happening.
> 
> Initially I disabled the folding if either symbol was a Thumb function. 
> However this ends up breaking the explicit cfi directives in libgcc, so I've 
> only disabled the folding when the first symbol is a Thumb function.

Wow, this is nasty!

I can understand why Richard, and presumably the ABI, wants this to
happen:

	ldr	ip, 1f
2:	add	ip, pc, ip
	bx	ip
1:	.word	foo - . - (2b - .)

But I'd be mighty confused if, say, some code tried to copy itself from
one location to another and expected "foo - ." to describe the number
of bytes to be copied.  And now "foo - ." and ". - foo" are assymetric.


-- 
Daniel Jacobowitz
CodeSourcery

Re: [patch] R_ARM_REL32 and Thumb functions.

[Richard Earnshaw]

On Thu, 2006-04-20 at 19:49, Daniel Jacobowitz wrote:
> On Thu, Apr 20, 2006 at 07:29:49PM +0100, Paul Brook wrote:
> > The attached patch makes the R_ARM_REL32 relocation set the low bit of the 
> > value when the relocated symbol is a Thumb function, as required by the ARM 
> > EABI.
> > 
> > I don't know if the current behavior is considered a bug or a feature for 
> > pre-EABI objects. For now I'm assuming bug, and making the change 
> > unconditionally. I can preserver the old behavior if anything depends on it.
> > 
> > A slight complication is that gas will try and fold relative expressions at 
> > assembly time. This folding is done in generic code, so gets the value wrong. 
> > e.g.
> > 
> > .thumb_func
> > foo:
> > .word foo - .
> > 
> > Will be folded to zero by gas/expr.c:expr.  I've [ab]used md_optimize_expr to 
> > prevent this happening.
> > 
> > Initially I disabled the folding if either symbol was a Thumb function. 
> > However this ends up breaking the explicit cfi directives in libgcc, so I've 
> > only disabled the folding when the first symbol is a Thumb function.
> 
> Wow, this is nasty!
> 
> I can understand why Richard, and presumably the ABI, wants this to
> happen:
> 
> 	ldr	ip, 1f
> 2:	add	ip, pc, ip
> 	bx	ip
> 1:	.word	foo - . - (2b - .)
> 
> But I'd be mighty confused if, say, some code tried to copy itself from
> one location to another and expected "foo - ." to describe the number
> of bytes to be copied.  And now "foo - ." and ". - foo" are assymetric.

It's only done if the symbol is a Thumb Function symbol (ie has type
STT_FUNC and addresses Thumb code).  So if you want to treat your code
as data, add some other symbol at the same address with a different type
and use that for the data accesses.  So

	.type F_as_data, object
	.type F_as_code, function
	.thumb_func
F_as_code:
F_as_data:
	...
	.word	F_as_code - .
	.word	F_as_data - .

Will cause the first .word entry to be a pc-relative code label, and the
second to be a pc-relative data label.

If you look at AAELF you'll see that the change here is to make
relocation processing consistent -- why should R_ARM_REL32 not set the T
bit when R_ARM_ABS32 does?

R.

Re: [patch] R_ARM_REL32 and Thumb functions.

[Richard Earnshaw]

On Thu, 2006-04-20 at 19:29, Paul Brook wrote:
> The attached patch makes the R_ARM_REL32 relocation set the low bit of the 
> value when the relocated symbol is a Thumb function, as required by the ARM 
> EABI.
> 
> I don't know if the current behavior is considered a bug or a feature for 
> pre-EABI objects. For now I'm assuming bug, and making the change 
> unconditionally. I can preserver the old behavior if anything depends on it.
> 
> A slight complication is that gas will try and fold relative expressions at 
> assembly time. This folding is done in generic code, so gets the value wrong. 
> e.g.
> 
> .thumb_func
> foo:
> .word foo - .
> 
> Will be folded to zero by gas/expr.c:expr.  I've [ab]used md_optimize_expr to 
> prevent this happening.
> 
> Initially I disabled the folding if either symbol was a Thumb function. 
> However this ends up breaking the explicit cfi directives in libgcc, so I've 
> only disabled the folding when the first symbol is a Thumb function.
> 
> Tested with cross to arm-eabi.
> Ok?
> 
> Paul
> 
> 2006-04-20  Paul Brook  <paul@codesourcery.com>
> 
> bfd/
> 	* elf32-arm.c (elf32_arm_final_link_relocate): Set thumb funciton bit
> 	for R_ARM_REL32.
> gas/
> 	* config/tc-arm.c (arm_optimize_expr): New function.
> 	(md_apply_fix): Set thumb funciton bit for PC-relative relocations.
> 	* config/tc-arm.c (md_optimize_expr): Define
> 	(arm_optimize_expr): Add prototype.
> 	(TC_FORCE_RELOCATION_SUB_SAME): Define.
> ld/testsuite/
> 	* ld-arm/arm-elf.exp: Add thumb-rel32.
> 	* ld-arm/thumb-rel32.d: New test.
> 	* ld-arm/thumb-rel32.s: New test.
> 
> ______________________________________________________________________
> Index: bfd/elf32-arm.c
> ===================================================================
> RCS file: /var/cvsroot/src-cvs/src/bfd/elf32-arm.c,v
> retrieving revision 1.70
> diff -u -p -r1.70 elf32-arm.c
> --- bfd/elf32-arm.c	16 Mar 2006 12:20:15 -0000	1.70
> +++ bfd/elf32-arm.c	20 Apr 2006 14:39:04 -0000
> @@ -3277,6 +3277,8 @@ elf32_arm_final_link_relocate (reloc_how
>  	  value -= (input_section->output_section->vma
>  		    + input_section->output_offset + rel->r_offset);
>  	  value += addend;
> +	  if (sym_flags == STT_ARM_TFUNC)
> +	    value |= 1;
>  	  break;
>  
>  	case R_ARM_PREL31:
> Index: gas/config/tc-arm.c
> ===================================================================
> RCS file: /var/cvsroot/src-cvs/src/gas/config/tc-arm.c,v
> retrieving revision 1.256
> diff -u -p -r1.256 tc-arm.c
> --- gas/config/tc-arm.c	7 Apr 2006 15:11:19 -0000	1.256
> +++ gas/config/tc-arm.c	20 Apr 2006 17:31:47 -0000
> @@ -11491,6 +11491,29 @@ get_thumb32_insn (char * buf)
>    return insn;
>  }
>  
> +
> +/* We usually want to set the low bit on the address of thumb function
> +   symbols.  In particular .word foo - . should have the low bit set.
> +   Generic code tries to fold the difference of two symbols to
> +   a constant.  Prevent this and force a relocation when the first symbols
> +   is a thumb function.  */
> +int
> +arm_optimize_expr (expressionS *l, operatorT op, expressionS *r)
> +{
> +  if (op == O_subtract
> +      && l->X_op == O_symbol
> +      && r->X_op == O_symbol
> +      && THUMB_IS_FUNC (l->X_add_symbol))
> +    {
> +      l->X_op = O_subtract;
> +      l->X_op_symbol = r->X_add_symbol;
> +      l->X_add_number -= r->X_add_number;
> +      return 1;
> +    }
> +  /* Process as normal.  */
> +  return 0;
> +}
> +
>  void
>  md_apply_fix (fixS *	fixP,
>  	       valueT * valP,
> @@ -12106,7 +12129,14 @@ md_apply_fix (fixS *	fixP,
>      case BFD_RELOC_ARM_TARGET1:
>      case BFD_RELOC_ARM_ROSEGREL32:
>      case BFD_RELOC_ARM_SBREL32:
> +      if (fixP->fx_done || !seg->use_rela_p)
> +	md_number_to_chars (buf, value, 4);
> +      break;
> +
>      case BFD_RELOC_32_PCREL:
> +      /* Set the low bit of the value if the target is a thumb function.  */
> +      if (fixP->fx_done && fixP->fx_addsy && THUMB_IS_FUNC(fixP->fx_addsy))
> +	value |= 1;

AFAICT, this is close, but not quite what AAELF says.  The relocation
expression is

	((S + A) | T) - .

That is, the T bit is orred in before the address of the place is
subtracted. 

Normally, this doesn't change anything since the relocation is used with
.word which has 4-byte alignment.  However, if a .4byte directive is
used, then there are no alignment constraints and the order of
processing becomes significant.

R.

Re: [patch] R_ARM_REL32 and Thumb functions.

[Paul Brook]

[-- Attachment #1: Type: text/plain, Size: 1325 bytes --]

> >      case BFD_RELOC_32_PCREL:
> > +      /* Set the low bit of the value if the target is a thumb function.
> >  */ +      if (fixP->fx_done && fixP->fx_addsy &&
> > THUMB_IS_FUNC(fixP->fx_addsy)) +	value |= 1;
>
> AFAICT, this is close, but not quite what AAELF says.  The relocation
> expression is
>
> 	((S + A) | T) - .
>
> That is, the T bit is orred in before the address of the place is
> subtracted.
>
> Normally, this doesn't change anything since the relocation is used with
> .word which has 4-byte alignment.  However, if a .4byte directive is
> used, then there are no alignment constraints and the order of
> processing becomes significant.

It turns out this code never triggers because we force an external relocation. 
However the bfd code to process R_ARM_REL32 has a similar bug.

Updated patch attached.
Tested with cross to arm-none-eabi.
Ok?

Paul

2006-04-28  Paul Brook  <paul@codesourcery.com>

bfd/
	* elf32-arm.c (elf32_arm_final_link_relocate): Set Thumb function bit
	for R_ARM_REL32.
gas/
	* config/tc-arm.c (arm_optimize_expr): New function.
	* config/tc-arm.h (md_optimize_expr): Define
	(arm_optimize_expr): Add prototype.
	(TC_FORCE_RELOCATION_SUB_SAME): Define.
ld/testsuite/
	* ld-arm/arm-elf.exp: Add thumb-rel32.
	* ld-arm/thumb-rel32.d: New test.
	* ld-arm/thumb-rel32.s: New test.

[-- Attachment #2: patch.rel32 --]
[-- Type: text/x-diff, Size: 4735 bytes --]

Index: bfd/elf32-arm.c
===================================================================
RCS file: /var/cvsroot/src-cvs/src/bfd/elf32-arm.c,v
retrieving revision 1.71
diff -u -p -r1.71 elf32-arm.c
--- bfd/elf32-arm.c	25 Apr 2006 17:46:15 -0000	1.71
+++ bfd/elf32-arm.c	28 Apr 2006 15:12:07 -0000
@@ -3274,9 +3274,11 @@ elf32_arm_final_link_relocate (reloc_how
 	  break;
 
 	case R_ARM_REL32:
+	  value += addend;
+	  if (sym_flags == STT_ARM_TFUNC)
+	    value |= 1;
 	  value -= (input_section->output_section->vma
 		    + input_section->output_offset + rel->r_offset);
-	  value += addend;
 	  break;
 
 	case R_ARM_PREL31:
Index: gas/config/tc-arm.c
===================================================================
RCS file: /var/cvsroot/src-cvs/src/gas/config/tc-arm.c,v
retrieving revision 1.261
diff -u -p -r1.261 tc-arm.c
--- gas/config/tc-arm.c	26 Apr 2006 16:03:02 -0000	1.261
+++ gas/config/tc-arm.c	28 Apr 2006 15:12:10 -0000
@@ -15811,6 +15811,29 @@ get_thumb32_insn (char * buf)
   return insn;
 }
 
+
+/* We usually want to set the low bit on the address of thumb function
+   symbols.  In particular .word foo - . should have the low bit set.
+   Generic code tries to fold the difference of two symbols to
+   a constant.  Prevent this and force a relocation when the first symbols
+   is a thumb function.  */
+int
+arm_optimize_expr (expressionS *l, operatorT op, expressionS *r)
+{
+  if (op == O_subtract
+      && l->X_op == O_symbol
+      && r->X_op == O_symbol
+      && THUMB_IS_FUNC (l->X_add_symbol))
+    {
+      l->X_op = O_subtract;
+      l->X_op_symbol = r->X_add_symbol;
+      l->X_add_number -= r->X_add_number;
+      return 1;
+    }
+  /* Process as normal.  */
+  return 0;
+}
+
 void
 md_apply_fix (fixS *	fixP,
 	       valueT * valP,
Index: gas/config/tc-arm.h
===================================================================
RCS file: /var/cvsroot/src-cvs/src/gas/config/tc-arm.h,v
retrieving revision 1.36
diff -u -p -r1.36 tc-arm.h
--- gas/config/tc-arm.h	8 Oct 2005 17:07:16 -0000	1.36
+++ gas/config/tc-arm.h	24 Apr 2006 14:59:51 -0000
@@ -83,6 +83,9 @@ struct fix;
   arm_relax_frag(segment, fragp, stretch)
 extern int arm_relax_frag (asection *, struct frag *, long);
 
+#define md_optimize_expr(l,o,r)		arm_optimize_expr (l, o, r)
+extern int arm_optimize_expr (expressionS *, operatorT, expressionS *);
+
 #define md_cleanup() arm_cleanup ()
 
 #define md_start_line_hook() arm_start_line_hook ()
@@ -148,6 +151,12 @@ extern void arm_md_end (void);
    || (FIX)->fx_r_type == BFD_RELOC_32			\
    || TC_FORCE_RELOCATION (FIX))
 
+/* Force output of R_ARM_REL32 relocations against thumb function symbols.
+   This is needed to ensure the low bit is handled correctly.  */
+#define TC_FORCE_RELOCATION_SUB_SAME(FIX, SEG)	\
+  (THUMB_IS_FUNC ((FIX)->fx_addsy)		\
+   || !SEG_NORMAL (SEG))
+
 #define TC_CONS_FIX_NEW cons_fix_new_arm
 
 #define MAX_MEM_FOR_RS_ALIGN_CODE 31
Index: ld/testsuite/ld-arm/arm-elf.exp
===================================================================
RCS file: /var/cvsroot/src-cvs/src/ld/testsuite/ld-arm/arm-elf.exp,v
retrieving revision 1.11
diff -u -p -r1.11 arm-elf.exp
--- ld/testsuite/ld-arm/arm-elf.exp	7 Mar 2006 08:39:21 -0000	1.11
+++ ld/testsuite/ld-arm/arm-elf.exp	24 Apr 2006 14:43:47 -0000
@@ -119,6 +119,9 @@ set armelftests {
     {"Thumb entry point" "-T arm.ld" "" {thumb-entry.s}
      {{readelf -h thumb-entry.d}}
      "thumb-entry"}
+    {"thumb-rel32" "-static -T arm.ld" "" {thumb-rel32.s}
+     {{objdump -s thumb-rel32.d}}
+     "thumb-rel32"}
 }
 
 run_ld_link_tests $armelftests
Index: ld/testsuite/ld-arm/thumb-rel32.d
===================================================================
RCS file: ld/testsuite/ld-arm/thumb-rel32.d
diff -N ld/testsuite/ld-arm/thumb-rel32.d
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ ld/testsuite/ld-arm/thumb-rel32.d	25 Apr 2006 18:22:46 -0000
@@ -0,0 +1,7 @@
+
+.*:     file format.*
+
+Contents of section .text:
+ 8000 (00000011 fffffffd 00ffffff f8000000|11000000 fdffffff 00f8ffff ff000000) .*
+# Ignore .ARM.attributes section
+#...
Index: ld/testsuite/ld-arm/thumb-rel32.s
===================================================================
RCS file: ld/testsuite/ld-arm/thumb-rel32.s
diff -N ld/testsuite/ld-arm/thumb-rel32.s
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ ld/testsuite/ld-arm/thumb-rel32.s	25 Apr 2006 18:23:00 -0000
@@ -0,0 +1,18 @@
+	.text
+	.arch armv4t
+	.global	_start
+	.type	_start, %function
+	.thumb_func
+_start:
+	.word bar - .
+	.word _start - .
+	.byte 0
+	.4byte (_start - .) + 1
+	.byte 0, 0, 0
+	.section .after, "ax", %progbits
+	.global bar
+	.type bar, %function
+	.thumb_func
+bar:
+	.word 0
+	.ident	"GCC: (GNU) 4.1.0 (CodeSourcery ARM)"

Re: [patch] R_ARM_REL32 and Thumb functions.

[Nick Clifton]

Hi Paul,

> 2006-04-28  Paul Brook  <paul@codesourcery.com>
> 
> bfd/
> 	* elf32-arm.c (elf32_arm_final_link_relocate): Set Thumb function bit
> 	for R_ARM_REL32.
> gas/
> 	* config/tc-arm.c (arm_optimize_expr): New function.
> 	* config/tc-arm.h (md_optimize_expr): Define
> 	(arm_optimize_expr): Add prototype.
> 	(TC_FORCE_RELOCATION_SUB_SAME): Define.
> ld/testsuite/
> 	* ld-arm/arm-elf.exp: Add thumb-rel32.
> 	* ld-arm/thumb-rel32.d: New test.
> 	* ld-arm/thumb-rel32.s: New test.

Approved for mainline.  I think that this should probably go into the 
2.17 branch as well.  What do you think ?

Cheers
   Nick

Re: [patch] R_ARM_REL32 and Thumb functions.

[Paul Brook]

On Tuesday 02 May 2006 13:22, Nick Clifton wrote:
> Hi Paul,
>
> > 2006-04-28  Paul Brook  <paul@codesourcery.com>
> >
> > bfd/
> > 	* elf32-arm.c (elf32_arm_final_link_relocate): Set Thumb function bit
> > 	for R_ARM_REL32.
> > gas/
> > 	* config/tc-arm.c (arm_optimize_expr): New function.
> > 	* config/tc-arm.h (md_optimize_expr): Define
> > 	(arm_optimize_expr): Add prototype.
> > 	(TC_FORCE_RELOCATION_SUB_SAME): Define.
> > ld/testsuite/
> > 	* ld-arm/arm-elf.exp: Add thumb-rel32.
> > 	* ld-arm/thumb-rel32.d: New test.
> > 	* ld-arm/thumb-rel32.s: New test.
>
> Approved for mainline.  I think that this should probably go into the
> 2.17 branch as well.  What do you think ?

Ok, done.

Paul

Re: [patch] R_ARM_REL32 and Thumb functions.

[Daniel Jacobowitz]

On Tue, May 02, 2006 at 02:20:08PM +0100, Paul Brook wrote:
> > Approved for mainline.  I think that this should probably go into the
> > 2.17 branch as well.  What do you think ?
> 
> Ok, done.

Yes - thanks.

-- 
Daniel Jacobowitz
CodeSourcery