[PATCH]: Make solib.c more multi-archable

[Jim Blandy]

If you implement Andrew's suggestion of wrapping it up in a function,
then I approve of this patch.



msnyder@cygnus.com writes:

> 
> Hello, 
> 
> This patch will allow solib.c to use the bfd to determine whether 
> it is ELF32 or ELF64, rather than using a compile-time macro.
> 
> This gets us closer to allowing a single GDB to debug both types
> of solibs.
> 
> 2000-05-03  Michael Snyder  <msnyder@seadog.cygnus.com>
> 
>         * solib.c (elf_locate_base, info_sharedlibrary_command):
>         Look at the bfd to determine if it is elf32 or elf64, rather
>         than using an ifdef.  This makes it runtime teststable and
>         multi-arch.
> 
> Index: solib.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/solib.c,v
> retrieving revision 1.11
> diff -p -r1.11 solib.c
> *** solib.c	2000/04/17 16:09:04	1.11
> --- solib.c	2000/05/04 00:15:08
> ***************
> *** 43,48 ****
> --- 43,51 ----
>   
>   #include "symtab.h"
>   #include "bfd.h"
> + #define _ELF_COMMON_H	/* Kludge: prevent inclusion of elf/common.h.
> + 			   Defines conflict with /usr/include/sys/elf.h  */
> + #include "elf-bfd.h"
>   #include "symfile.h"
>   #include "objfiles.h"
>   #include "gdbcore.h"
> *************** elf_locate_base ()
> *** 726,781 ****
>     /* Find the DT_DEBUG entry in the the .dynamic section.
>        For mips elf we look for DT_MIPS_RLD_MAP, mips elf apparently has
>        no DT_DEBUG entries.  */
> ! #ifndef TARGET_ELF64
> !   for (bufend = buf + dyninfo_sect_size;
> !        buf < bufend;
> !        buf += sizeof (Elf32_External_Dyn))
> !     {
> !       Elf32_External_Dyn *x_dynp = (Elf32_External_Dyn *) buf;
> !       long dyn_tag;
> !       CORE_ADDR dyn_ptr;
> ! 
> !       dyn_tag = bfd_h_get_32 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
> !       if (dyn_tag == DT_NULL)
> ! 	break;
> !       else if (dyn_tag == DT_DEBUG)
>   	{
> ! 	  dyn_ptr = bfd_h_get_32 (exec_bfd, (bfd_byte *) x_dynp->d_un.d_ptr);
> ! 	  return dyn_ptr;
> ! 	}
>   #ifdef DT_MIPS_RLD_MAP
> !       else if (dyn_tag == DT_MIPS_RLD_MAP)
> ! 	{
> ! 	  char pbuf[TARGET_PTR_BIT / HOST_CHAR_BIT];
>   
> ! 	  /* DT_MIPS_RLD_MAP contains a pointer to the address
> ! 	     of the dynamic link structure.  */
> ! 	  dyn_ptr = bfd_h_get_32 (exec_bfd, (bfd_byte *) x_dynp->d_un.d_ptr);
> ! 	  if (target_read_memory (dyn_ptr, pbuf, sizeof (pbuf)))
> ! 	    return 0;
> ! 	  return extract_unsigned_integer (pbuf, sizeof (pbuf));
> ! 	}
>   #endif
>       }
> ! #else /* ELF64 */
> !   for (bufend = buf + dyninfo_sect_size;
> !        buf < bufend;
> !        buf += sizeof (Elf64_External_Dyn))
> !     {
> !       Elf64_External_Dyn *x_dynp = (Elf64_External_Dyn *) buf;
> !       long dyn_tag;
> !       CORE_ADDR dyn_ptr;
> ! 
> !       dyn_tag = bfd_h_get_64 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
> !       if (dyn_tag == DT_NULL)
> ! 	break;
> !       else if (dyn_tag == DT_DEBUG)
>   	{
> ! 	  dyn_ptr = bfd_h_get_64 (exec_bfd, (bfd_byte *) x_dynp->d_un.d_ptr);
> ! 	  return dyn_ptr;
>   	}
>       }
> - #endif
>   
>     /* DT_DEBUG entry not found.  */
>     return 0;
> --- 729,790 ----
>     /* Find the DT_DEBUG entry in the the .dynamic section.
>        For mips elf we look for DT_MIPS_RLD_MAP, mips elf apparently has
>        no DT_DEBUG entries.  */
> !   if ((get_elf_backend_data (exec_bfd))->s->arch_size == 32)
> !     { /* 32-bit elf */
> !       for (bufend = buf + dyninfo_sect_size;
> ! 	   buf < bufend;
> ! 	   buf += sizeof (Elf32_External_Dyn))
>   	{
> ! 	  Elf32_External_Dyn *x_dynp = (Elf32_External_Dyn *) buf;
> ! 	  long dyn_tag;
> ! 	  CORE_ADDR dyn_ptr;
> ! 
> ! 	  dyn_tag = bfd_h_get_32 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
> ! 	  if (dyn_tag == DT_NULL)
> ! 	    break;
> ! 	  else if (dyn_tag == DT_DEBUG)
> ! 	    {
> ! 	      dyn_ptr = bfd_h_get_32 (exec_bfd, 
> ! 				      (bfd_byte *) x_dynp->d_un.d_ptr);
> ! 	      return dyn_ptr;
> ! 	    }
>   #ifdef DT_MIPS_RLD_MAP
> ! 	  else if (dyn_tag == DT_MIPS_RLD_MAP)
> ! 	    {
> ! 	      char pbuf[TARGET_PTR_BIT / HOST_CHAR_BIT];
>   
> ! 	      /* DT_MIPS_RLD_MAP contains a pointer to the address
> ! 		 of the dynamic link structure.  */
> ! 	      dyn_ptr = bfd_h_get_32 (exec_bfd, 
> ! 				      (bfd_byte *) x_dynp->d_un.d_ptr);
> ! 	      if (target_read_memory (dyn_ptr, pbuf, sizeof (pbuf)))
> ! 		return 0;
> ! 	      return extract_unsigned_integer (pbuf, sizeof (pbuf));
> ! 	    }
>   #endif
> + 	}
>       }
> !   else /* 64-bit elf */
> !     {
> !       for (bufend = buf + dyninfo_sect_size;
> ! 	   buf < bufend;
> ! 	   buf += sizeof (Elf64_External_Dyn))
>   	{
> ! 	  Elf64_External_Dyn *x_dynp = (Elf64_External_Dyn *) buf;
> ! 	  long dyn_tag;
> ! 	  CORE_ADDR dyn_ptr;
> ! 
> ! 	  dyn_tag = bfd_h_get_64 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
> ! 	  if (dyn_tag == DT_NULL)
> ! 	    break;
> ! 	  else if (dyn_tag == DT_DEBUG)
> ! 	    {
> ! 	      dyn_ptr = bfd_h_get_64 (exec_bfd, 
> ! 				      (bfd_byte *) x_dynp->d_un.d_ptr);
> ! 	      return dyn_ptr;
> ! 	    }
>   	}
>       }
>   
>     /* DT_DEBUG entry not found.  */
>     return 0;
> *************** info_sharedlibrary_command (ignore, from
> *** 1491,1503 ****
>         return;
>       }
>   
> ! #ifndef TARGET_ELF64
> !   addr_width = 8 + 4;
> !   addr_fmt = "08l";
> ! #else
> !   addr_width = 16 + 4;
> !   addr_fmt = "016l";
> ! #endif
>   
>     update_solib_list (from_tty, 0);
>   
> --- 1500,1515 ----
>         return;
>       }
>   
> !   if ((get_elf_backend_data (exec_bfd))->s->arch_size == 32)
> !     { /* 32-bit elf */
> !       addr_width = 8 + 4;
> !       addr_fmt = "08l";
> !     }
> !   else /* 64-bit elf */
> !     {
> !       addr_width = 16 + 4;
> !       addr_fmt = "016l";
> !     }
>   
>     update_solib_list (from_tty, 0);
>   
>