[16/18] make TS_IDENTIFIER be a substructure of TS_BASE

Now that we've done the requisite surgery on the C++ FE, we can
eliminate TREE_CHAIN and TREE_TYPE from IDENTIFIER_NODEs.  Doing so
turns up a couple different places that need to be tweaked.

The bit I'm not quite sure about is free_lang_data_in_decl and
find_decls_types_r.  Previously, due to C++ FE machinations, we'd free
REAL_IDENTIFIER_TYPE_VALUE naturally, through punning of TREE_TYPE.  Now
that we've shuffled that field into lang_identifier, that bit of
identifiers won't get freed...and I don't know if that causes problems.
Anybody more knowledgeable than I willing to weigh in on that?

-Nathan

gcc/
	* print-tree.c (print_node): Check for TS_TYPED structures before
	accessing TREE_TYPE.
	* tree.h (struct tree_identifier): Inherit from tree_base, not
	tree_common.
	(HT_IDENT_TO_GCC_IDENT): Adjust for said change.
	* tree.c (initialize_tree_contains_struct): Mark TS_IDENTIFIER as
	TS_BASE instead of TS_COMMON.
	(free_lang_data_in_decl): Don't set TREE_TYPE of DECL_NAME.
	(find_decls_types_r): Check for TS_TYPED structures before accessing
	TREE_TYPE.
	* varasm.c (assemble_name): Remove assert.

gcc/c-family/
	* c-common.h (struct c_common_identifier): Inherit from tree_base,
	not tree_common.

On Fri, Mar 11, 2011 at 5:23 AM, Nathan Froyd <froydnj@codesourcery.com> wrote:
> Now that we've done the requisite surgery on the C++ FE, we can
> eliminate TREE_CHAIN and TREE_TYPE from IDENTIFIER_NODEs.  Doing so
> turns up a couple different places that need to be tweaked.
>
> The bit I'm not quite sure about is free_lang_data_in_decl and
> find_decls_types_r.  Previously, due to C++ FE machinations, we'd free
> REAL_IDENTIFIER_TYPE_VALUE naturally, through punning of TREE_TYPE.  Now
> that we've shuffled that field into lang_identifier, that bit of
> identifiers won't get freed...and I don't know if that causes problems.
> Anybody more knowledgeable than I willing to weigh in on that?

At some point we should zero-out DECL/TYPE_LANG_SPECIFIC, I
don't remember why we don't do that.

The patch is ok for 4.7 anyway.

Thanks,
Richard.

> -Nathan
>
> gcc/
>        * print-tree.c (print_node): Check for TS_TYPED structures before
>        accessing TREE_TYPE.
>        * tree.h (struct tree_identifier): Inherit from tree_base, not
>        tree_common.
>        (HT_IDENT_TO_GCC_IDENT): Adjust for said change.
>        * tree.c (initialize_tree_contains_struct): Mark TS_IDENTIFIER as
>        TS_BASE instead of TS_COMMON.
>        (free_lang_data_in_decl): Don't set TREE_TYPE of DECL_NAME.
>        (find_decls_types_r): Check for TS_TYPED structures before accessing
>        TREE_TYPE.
>        * varasm.c (assemble_name): Remove assert.
>
> gcc/c-family/
>        * c-common.h (struct c_common_identifier): Inherit from tree_base,
>        not tree_common.
>
> diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
> index e7fe209..961dea7 100644
> --- a/gcc/c-family/c-common.h
> +++ b/gcc/c-family/c-common.h
> @@ -306,7 +306,7 @@ enum c_tree_index
>  /* Identifier part common to the C front ends.  Inherits from
>    tree_identifier, despite appearances.  */
>  struct GTY(()) c_common_identifier {
> -  struct tree_common common;
> +  struct tree_base base;
>   struct cpp_hashnode node;
>  };
>
> diff --git a/gcc/print-tree.c b/gcc/print-tree.c
> index d8acd1b..1a1e33f 100644
> --- a/gcc/print-tree.c
> +++ b/gcc/print-tree.c
> @@ -321,7 +321,7 @@ print_node (FILE *file, const char *prefix, tree node, int indent)
>       if (indent <= 4)
>        print_node_brief (file, "type", TREE_TYPE (node), indent + 4);
>     }
> -  else
> +  else if (CODE_CONTAINS_STRUCT (code, TS_TYPED))
>     {
>       print_node (file, "type", TREE_TYPE (node), indent + 4);
>       if (TREE_TYPE (node))
> diff --git a/gcc/tree.c b/gcc/tree.c
> index 81ee05e..001e8c8 100644
> --- a/gcc/tree.c
> +++ b/gcc/tree.c
> @@ -366,6 +366,7 @@ initialize_tree_contains_struct (void)
>       switch (ts_code)
>        {
>        case TS_TYPED:
> +       case TS_IDENTIFIER:
>          MARK_TS_BASE (code);
>          break;
>
> @@ -383,7 +384,6 @@ initialize_tree_contains_struct (void)
>          MARK_TS_TYPED (code);
>          break;
>
> -       case TS_IDENTIFIER:
>        case TS_DECL_MINIMAL:
>        case TS_TYPE:
>        case TS_LIST:
> @@ -4495,10 +4495,6 @@ free_lang_data_in_decl (tree decl)
>   TREE_LANG_FLAG_5 (decl) = 0;
>   TREE_LANG_FLAG_6 (decl) = 0;
>
> -  /* Identifiers need not have a type.  */
> -  if (DECL_NAME (decl))
> -    TREE_TYPE (DECL_NAME (decl)) = NULL_TREE;
> -
>   free_lang_data_in_one_sizepos (&DECL_SIZE (decl));
>   free_lang_data_in_one_sizepos (&DECL_SIZE_UNIT (decl));
>   if (TREE_CODE (decl) == FIELD_DECL)
> @@ -4795,7 +4791,8 @@ find_decls_types_r (tree *tp, int *ws, void *data)
>       fld_worklist_push (BLOCK_ABSTRACT_ORIGIN (t), fld);
>     }
>
> -  fld_worklist_push (TREE_TYPE (t), fld);
> +  if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED))
> +    fld_worklist_push (TREE_TYPE (t), fld);
>
>   return NULL_TREE;
>  }
> diff --git a/gcc/tree.h b/gcc/tree.h
> index c81186a..f4d18f8 100644
> --- a/gcc/tree.h
> +++ b/gcc/tree.h
> @@ -1529,11 +1529,11 @@ struct GTY(()) tree_vector {
>    pointer, and vice versa.  */
>
>  #define HT_IDENT_TO_GCC_IDENT(NODE) \
> -  ((tree) ((char *) (NODE) - sizeof (struct tree_common)))
> +  ((tree) ((char *) (NODE) - sizeof (struct tree_base)))
>  #define GCC_IDENT_TO_HT_IDENT(NODE) (&((struct tree_identifier *) (NODE))->id)
>
>  struct GTY(()) tree_identifier {
> -  struct tree_common common;
> +  struct tree_base base;
>   struct ht_identifier id;
>  };
>
> diff --git a/gcc/varasm.c b/gcc/varasm.c
> index 76675cd..4c429de 100644
> --- a/gcc/varasm.c
> +++ b/gcc/varasm.c
> @@ -2300,7 +2300,6 @@ assemble_name (FILE *file, const char *name)
>       ultimate_transparent_alias_target (&id);
>       if (id != id_orig)
>        name = IDENTIFIER_POINTER (id);
> -      gcc_assert (! TREE_CHAIN (id));
>     }
>
>   assemble_name_raw (file, name);
> --
> 1.7.0.4
>
>

On Fri, Mar 11, 2011 at 02:12:06PM +0100, Richard Guenther wrote:
> On Fri, Mar 11, 2011 at 5:23 AM, Nathan Froyd <froydnj@codesourcery.com> wrote:
> > Now that we've done the requisite surgery on the C++ FE, we can
> > eliminate TREE_CHAIN and TREE_TYPE from IDENTIFIER_NODEs.  Doing so
> > turns up a couple different places that need to be tweaked.
> 
> At some point we should zero-out DECL/TYPE_LANG_SPECIFIC, I
> don't remember why we don't do that.
> 
> The patch is ok for 4.7 anyway.

Given Jason's comments on patch 15/18, I'll be dropping chunks of this
and just eliminating TREE_CHAIN from IDENTIFIER_NODEs for now.  Since
those changes are trivial, I'm going to assume I don't need separate
approval for those (appropriate testing will of course be performed).

-Nathan