Re: Merge C++ conversion into trunk (3/6 - gengtype C++ support)

[Diego Novillo <dnovillo at google dot com>]

On 12-08-14 01:39 , Laurynas Biveinis wrote:

> >          (walk_type): Set D->IN_PTR_FILED when walking a TYPE_POINTER.
>
> "FIELD"

Done.

> > +fields is completely handled by user-provided routines.  Section
> > +@ref{User GC} for details on what functions need to be provided.
>
> "See Section ... " ?

Done.

> > +code is generated.  For these types, the user is required to provide
> > +three functions: one to act as a marker for garbage collection, and
> > +two functions to act as marker and pointer walking for pre-compiled
> > +headers.
>
> s/walking/walker ?

Done.

> > +In general, each marker @code{M} should call @code{M} for every
> > +pointer field in the structure.  Fields that are not allocated in GC
> > +or are not pointers can be ignored.
>
> "must be ignored"

Done.

> > +create_user_defined_type (const char *type_name, struct fileloc *pos)
> ...
> > +     template by preteding that each type is a field of TY.  This is needed to
>
> pretending

Done.

> > @@ -548,20 +603,30 @@ resolve_typedef (const char *s, struct fileloc *pos)
> >     for (p = typedefs; p != NULL; p = p->next)
> >       if (strcmp (p->name, s) == 0)
> >         return p->type;
> > -  error_at_line (pos, "unidentified type `%s'", s);
> > -  return &scalar_nonchar;      /* treat as "int" */
> > +
> > +  /* If we did not find a typedef registered, assume this is a name
> > +     for a user-defined type which will need to provide its own
> > +     marking functions.
> > +
> > +     FIXME cxx-conversion. Emit an error once explicit annotations
> > +     for marking user types are implemented.  */
> > +  return create_user_defined_type (s, pos);
>
> Are "explicit annotations for marking user types" referring to GTY((user))?

Actually, the comment is wrong.  When we don't recognize the type, we 
simply consider this type as implicitly user-defined.

> > +static const char *
> > +filter_type_name (const char *type_name)
> > +{
>
> Maybe this function should return const-less char *? The casts to cast
> the const away for freeing it look a bit awkward.

Done.

> > +
> > +/* User-callable entry point for marking string X.  */
>
> "points"

Done.

> > +
> > +/* User-callable entry point for marking string X.  */
>
> "points"

Done.

> > --- a/gcc/stringpool.c
> > +++ b/gcc/stringpool.c
> > @@ -49,7 +49,7 @@ static const char digit_vector[] = {
> >
> >   struct ht *ident_hash;
> >
> > -static hashnode alloc_node (hash_table *);
> > +static hashnode alloc_node (cpp_hash_table *);
> >   static int mark_ident (struct cpp_reader *, hashnode, const void *);
> >
> >   static void *
> > @@ -70,7 +70,7 @@ init_stringpool (void)
> >
> >   /* Allocate a hash node.  */
> >   static hashnode
> > -alloc_node (hash_table *table ATTRIBUTE_UNUSED)
> > +alloc_node (cpp_hash_table *table ATTRIBUTE_UNUSED)
> >   {
> >     return GCC_IDENT_TO_HT_IDENT (make_node (IDENTIFIER_NODE));
> >   }
>
> These changes are not in the ChangeLog, are they intentional?

Sorry.  They belong to the hash table patch.  Both patches touched the 
same file and I missed splitting these hunks.

> > diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
>
> > +/* Garbage collection support for edge_def.  */
> > +
> > +extern void gt_ggc_mx (tree&);
> > +extern void gt_ggc_mx (gimple&);
> > +extern void gt_ggc_mx (rtx&);
> > +extern void gt_ggc_mx (basic_block&);
>
> > +/* PCH support for edge_def.  */
> > +
> > +extern void gt_pch_nx (tree&);
> > +extern void gt_pch_nx (gimple&);
> > +extern void gt_pch_nx (rtx&);
> > +extern void gt_pch_nx (basic_block&);
>
> I wonder if these externs can be avoided by including gtype-desc.h. I
> realize that gtype-desc.h declares a lot of stuff, but if tree-cfg.c
> already declares GC roots, then it already should be pulling that
> header in in through gt-tree-cfg.h.

Not really.  These are never really defined anywhere.  They are emitted 
in gtype-desc.c, but we never emit prototypes for them.  Going down that 
road ends up in turning gengtype upside-down.


Diego.