Re: [PATCH] move gdbarch object from objfile to per-BFD

[Mark Kettenis <mark dot kettenis at xs4all dot nl>]

> From: Tom Tromey <tromey@redhat.com>
> Date: Mon,  5 Aug 2013 11:56:25 -0600
> 
> This moves the "gdbarch" field from the objfile into the BFD.
> 
> This field's value is derived from the BFD and is immutable over the
> lifetime of the BFD.  This makes it a reasonable candidate for pushing
> into the per-BFD object.
> 
> This is part of the long-term objfile splitting project.  In the long
> run I think this patch will make it simpler to moves types from the
> objfile to the per-BFD object; but the patch makes sense as a minor
> cleanup by itself.

The pointer chasing gets a bit ridiculous though.  Perhaps it needs a
little helper function?

> Built and regtested on x86-64 Fedora 18.
> 
> 	* cp-namespace.c (cp_lookup_symbol_imports_or_template): Update.
> 	* elfread.c (elf_rel_plt_read, elf_gnu_ifunc_record_cache)
> 	(elf_gnu_ifunc_resolve_by_got): Update.
> 	* jit.c (jit_object_close_impl): Update.
> 	* jv-lang.c (get_dynamics_objfile): Update.
> 	* linespec.c (add_minsym): Update.
> 	* objfiles.c (get_objfile_bfd_data): Initialize 'gdbarch' field.
> 	(allocate_objfile): Don't initialize 'gdbarch' field.
> 	(get_objfile_arch): Update.
> 	* objfiles.h (struct objfile_per_bfd_storage) <gdbarch>: New field,
> 	moved from...
> 	(struct objfile) <gdbarch>: ... here.  Remove.
> 	* stap-probe.c (stap_can_evaluate_probe_arguments): Update.
> 	* symfile.c (init_entry_point_info): Update.
> ---
>  gdb/cp-namespace.c |  3 ++-
>  gdb/elfread.c      |  6 +++---
>  gdb/jit.c          |  2 +-
>  gdb/jv-lang.c      |  2 +-
>  gdb/linespec.c     |  2 +-
>  gdb/objfiles.c     |  8 ++++----
>  gdb/objfiles.h     | 14 +++++++-------
>  gdb/stap-probe.c   |  2 +-
>  gdb/symfile.c      |  4 ++--
>  9 files changed, 22 insertions(+), 21 deletions(-)
> 
> diff --git a/gdb/cp-namespace.c b/gdb/cp-namespace.c
> index 755aeef..3c7ce15 100644
> --- a/gdb/cp-namespace.c
> +++ b/gdb/cp-namespace.c
> @@ -473,7 +473,8 @@ cp_lookup_symbol_imports_or_template (const char *scope,
>  	  char *name_copy = xstrdup (SYMBOL_NATURAL_NAME (function));
>  	  struct cleanup *cleanups = make_cleanup (xfree, name_copy);
>  	  const struct language_defn *lang = language_def (language_cplus);
> -	  struct gdbarch *arch = SYMBOL_SYMTAB (function)->objfile->gdbarch;
> +	  struct gdbarch *arch
> +	    = SYMBOL_SYMTAB (function)->objfile->per_bfd->gdbarch;
>  	  const struct block *parent = BLOCK_SUPERBLOCK (block);
>  
>  	  while (1)
> diff --git a/gdb/elfread.c b/gdb/elfread.c
> index 1aa10d1..975a0e4 100644
> --- a/gdb/elfread.c
> +++ b/gdb/elfread.c
> @@ -636,7 +636,7 @@ elf_rel_plt_read (struct objfile *objfile, asymbol **dyn_symbol_table)
>    char *string_buffer = NULL;
>    size_t string_buffer_size = 0;
>    struct cleanup *back_to;
> -  struct gdbarch *gdbarch = objfile->gdbarch;
> +  struct gdbarch *gdbarch = objfile->per_bfd->gdbarch;
>    struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
>    size_t ptr_size = TYPE_LENGTH (ptr_type);
>  
> @@ -797,7 +797,7 @@ elf_gnu_ifunc_record_cache (const char *name, CORE_ADDR addr)
>    if (*slot != NULL)
>      {
>        struct elf_gnu_ifunc_cache *entry_found_p = *slot;
> -      struct gdbarch *gdbarch = objfile->gdbarch;
> +      struct gdbarch *gdbarch = objfile->per_bfd->gdbarch;
>  
>        if (entry_found_p->addr != addr)
>  	{
> @@ -877,7 +877,7 @@ elf_gnu_ifunc_resolve_by_got (const char *name, CORE_ADDR *addr_p)
>    ALL_PSPACE_OBJFILES (current_program_space, objfile)
>      {
>        bfd *obfd = objfile->obfd;
> -      struct gdbarch *gdbarch = objfile->gdbarch;
> +      struct gdbarch *gdbarch = objfile->per_bfd->gdbarch;
>        struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
>        size_t ptr_size = TYPE_LENGTH (ptr_type);
>        CORE_ADDR pointer_address, addr;
> diff --git a/gdb/jit.c b/gdb/jit.c
> index 6fc8524..c565b6b 100644
> --- a/gdb/jit.c
> +++ b/gdb/jit.c
> @@ -786,7 +786,7 @@ jit_object_close_impl (struct gdb_symbol_callbacks *cb,
>    priv_data = cb->priv_data;
>  
>    objfile = allocate_objfile (NULL, 0);
> -  objfile->gdbarch = target_gdbarch ();
> +  objfile->per_bfd->gdbarch = target_gdbarch ();
>  
>    terminate_minimal_symbol_table (objfile);
>  
> diff --git a/gdb/jv-lang.c b/gdb/jv-lang.c
> index 1ef1296..bba94f2 100644
> --- a/gdb/jv-lang.c
> +++ b/gdb/jv-lang.c
> @@ -119,7 +119,7 @@ get_dynamics_objfile (struct gdbarch *gdbarch)
>        /* Mark it as shared so that it is cleared when the inferior is
>  	 re-run.  */
>        dynamics_objfile = allocate_objfile (NULL, OBJF_SHARED);
> -      dynamics_objfile->gdbarch = gdbarch;
> +      dynamics_objfile->per_bfd->gdbarch = gdbarch;
>  
>        data = XCNEW (struct jv_per_objfile_data);
>        set_objfile_data (dynamics_objfile, jv_dynamics_objfile_data_key, data);
> diff --git a/gdb/linespec.c b/gdb/linespec.c
> index 2f2a1a3..d332206 100644
> --- a/gdb/linespec.c
> +++ b/gdb/linespec.c
> @@ -3492,7 +3492,7 @@ add_minsym (struct minimal_symbol *minsym, void *d)
>  	  {
>  	    /* Make sure this minsym is not a function descriptor
>  	       before we decide to discard it.  */
> -	    struct gdbarch *gdbarch = info->objfile->gdbarch;
> +	    struct gdbarch *gdbarch = info->objfile->per_bfd->gdbarch;
>  	    CORE_ADDR addr = gdbarch_convert_from_func_ptr_addr
>  			       (gdbarch, SYMBOL_VALUE_ADDRESS (minsym),
>  				&current_target);
> diff --git a/gdb/objfiles.c b/gdb/objfiles.c
> index 759159c..2b8cf4e 100644
> --- a/gdb/objfiles.c
> +++ b/gdb/objfiles.c
> @@ -143,6 +143,9 @@ get_objfile_bfd_data (struct objfile *objfile, struct bfd *abfd)
>  	{
>  	  storage = bfd_zalloc (abfd, sizeof (struct objfile_per_bfd_storage));
>  	  set_bfd_data (abfd, objfiles_bfd_data, storage);
> +
> +	  /* Look up the gdbarch associated with the BFD.  */
> +	  storage->gdbarch = gdbarch_from_bfd (abfd);
>  	}
>        else
>  	storage = OBSTACK_ZALLOC (&objfile->objfile_obstack,
> @@ -282,9 +285,6 @@ allocate_objfile (bfd *abfd, int flags)
>    gdb_bfd_ref (abfd);
>    if (abfd != NULL)
>      {
> -      /* Look up the gdbarch associated with the BFD.  */
> -      objfile->gdbarch = gdbarch_from_bfd (abfd);
> -
>        objfile->name = bfd_get_filename (abfd);
>        objfile->mtime = bfd_get_mtime (abfd);
>  
> @@ -335,7 +335,7 @@ allocate_objfile (bfd *abfd, int flags)
>  struct gdbarch *
>  get_objfile_arch (struct objfile *objfile)
>  {
> -  return objfile->gdbarch;
> +  return objfile->per_bfd->gdbarch;
>  }
>  
>  /* If there is a valid and known entry point, function fills *ENTRY_P with it
> diff --git a/gdb/objfiles.h b/gdb/objfiles.h
> index 84167e0..5b762e4 100644
> --- a/gdb/objfiles.h
> +++ b/gdb/objfiles.h
> @@ -178,6 +178,13 @@ struct objfile_per_bfd_storage
>  
>    /* Byte cache for macros.  */
>    struct bcache *macro_cache;
> +
> +  /* The gdbarch associated with the BFD.  Note that this gdbarch is
> +     determined solely from BFD information, without looking at target
> +     information.  The gdbarch determined from a running target may
> +     differ from this e.g. with respect to register types and names.  */
> +
> +  struct gdbarch *gdbarch;
>  };
>  
>  /* Master structure for keeping track of each file from which
> @@ -248,13 +255,6 @@ struct objfile
>  
>      struct objfile_per_bfd_storage *per_bfd;
>  
> -    /* The gdbarch associated with the BFD.  Note that this gdbarch is
> -       determined solely from BFD information, without looking at target
> -       information.  The gdbarch determined from a running target may
> -       differ from this e.g. with respect to register types and names.  */
> -
> -    struct gdbarch *gdbarch;
> -
>      /* The modification timestamp of the object file, as of the last time
>         we read its symbols.  */
>  
> diff --git a/gdb/stap-probe.c b/gdb/stap-probe.c
> index cbbdf39..26c992c 100644
> --- a/gdb/stap-probe.c
> +++ b/gdb/stap-probe.c
> @@ -1086,7 +1086,7 @@ static int
>  stap_can_evaluate_probe_arguments (struct probe *probe_generic)
>  {
>    struct stap_probe *stap_probe = (struct stap_probe *) probe_generic;
> -  struct gdbarch *gdbarch = stap_probe->p.objfile->gdbarch;
> +  struct gdbarch *gdbarch = stap_probe->p.objfile->per_bfd->gdbarch;
>  
>    /* For SystemTap probes, we have to guarantee that the method
>       stap_is_single_operand is defined on gdbarch.  If it is not, then it
> diff --git a/gdb/symfile.c b/gdb/symfile.c
> index 5129105..352c5ec 100644
> --- a/gdb/symfile.c
> +++ b/gdb/symfile.c
> @@ -884,14 +884,14 @@ init_entry_point_info (struct objfile *objfile)
>        /* Make certain that the address points at real code, and not a
>  	 function descriptor.  */
>        entry_point
> -	= gdbarch_convert_from_func_ptr_addr (objfile->gdbarch,
> +	= gdbarch_convert_from_func_ptr_addr (objfile->per_bfd->gdbarch,
>  					      entry_point,
>  					      &current_target);
>  
>        /* Remove any ISA markers, so that this matches entries in the
>  	 symbol table.  */
>        objfile->ei.entry_point
> -	= gdbarch_addr_bits_remove (objfile->gdbarch, entry_point);
> +	= gdbarch_addr_bits_remove (objfile->per_bfd->gdbarch, entry_point);
>      }
>  }
>  
> -- 
> 1.8.1.4
> 
>