[csl-arm] SymbianOS calls via PLT from thumb mode

[Paul Brook <paul at codesourcery dot com>]

The SymbianOS PLT does not contain thumb stubs, so we need to use blx to jump 
to the plt entry from thumb mode.
Long-term we want to make this work for all armv5 targets, as discussed here:
http://sourceware.org/ml/binutils/2005-03/msg00438.html

I've applied the attached patch as a Symbian-specific short-term fix to the 
binutils-csl-arm-2005q1-branch.

Paul

2005-03-29  Julian Brown  <julian@codesourcery.com>

 * elf32-arm.c (elf32_arm_final_link_relocate): Use blx to get to
 symbian plt entries from thumb mode.

? bfd/doc/bfd.info
? bfd/doc/bfd.info-1
? gas/doc/as.info
? gas/doc/as.info-1
Index: bfd/elf32-arm.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-arm.c,v
retrieving revision 1.26
diff -c -p -r1.26 elf32-arm.c
*** bfd/elf32-arm.c	22 Mar 2005 15:39:32 -0000	1.26
--- bfd/elf32-arm.c	24 Mar 2005 18:05:56 -0000
*************** elf32_arm_final_link_relocate (reloc_how
*** 2650,2655 ****
--- 2650,2656 ----
  	bfd_signed_vma reloc_signed_min = ~ reloc_signed_max;
  	bfd_vma check;
  	bfd_signed_vma signed_check;
+ 	bfd_boolean thumb_plt_call = FALSE;
  
  	/* Need to refetch the addend and squish the two 11 bit pieces
  	   together.  */
*************** elf32_arm_final_link_relocate (reloc_how
*** 2699,2706 ****
  	    value = (splt->output_section->vma
  		     + splt->output_offset
  		     + h->plt.offset);
! 	    /* Target the Thumb stub before the ARM PLT entry.  */
! 	    value -= 4;
  	    *unresolved_reloc_p = FALSE;
  	  }
  
--- 2700,2719 ----
  	    value = (splt->output_section->vma
  		     + splt->output_offset
  		     + h->plt.offset);
!  	    if (globals->symbian_p)
!  	      {
!  		/* On SymbianOS, we are guaranteed to be using at least ARMv5t.
!  		   Convert the BL to a BLX instruction to call the ARM-mode PLT
!  		   entry.  */
!  		if ((lower_insn & (0x3 << 11)) == 0x3 << 11)
! 		  {
! 		    lower_insn = (lower_insn & ~(0x3 << 11)) | 0x1 << 11;
! 		    thumb_plt_call = TRUE;
! 		  }
!  	      }
!  	    else
!  	      /* Target the Thumb stub before the ARM PLT entry.  */
!  	      value -= PLT_THUMB_STUB_SIZE;
  	    *unresolved_reloc_p = FALSE;
  	  }
  
*************** elf32_arm_final_link_relocate (reloc_how
*** 2724,2731 ****
  	  overflow = TRUE;
  
  #ifndef OLD_ARM_ABI
! 	if (r_type == R_ARM_THM_XPC22
! 	    && ((lower_insn & 0x1800) == 0x0800))
  	  /* For a BLX instruction, make sure that the relocation is rounded up
  	     to a word boundary.  This follows the semantics of the instruction
  	     which specifies that bit 1 of the target address will come from bit
--- 2737,2745 ----
  	  overflow = TRUE;
  
  #ifndef OLD_ARM_ABI
! 	if ((r_type == R_ARM_THM_XPC22
! 	     && ((lower_insn & 0x1800) == 0x0800))
! 	    || thumb_plt_call)
  	  /* For a BLX instruction, make sure that the relocation is rounded up
  	     to a word boundary.  This follows the semantics of the instruction
  	     which specifies that bit 1 of the target address will come from bit