Re: [PATCH] Do not use ENUM_BITFIELD

[Guinevere Larsen <guinevere@redhat.com>]

On 5/24/26 5:29 PM, Tom Tromey wrote:
> C++ always allows enum bitfields, so gdb no longer needs to use the
> ENUM_BITFIELD macro.
>
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32821

Reading over what the macro does, this patch seems pretty obvious. I 
tested this by rebuilding quickly and see no issues, so

Reviewed-By: Guinevere Larsen <guinevere@redhat.com>

-- 
Cheers,
Guinevere Larsen
It/she

> ---
>   gdb/cli/cli-decode.h            |  2 +-
>   gdb/dwarf2/abbrev.h             |  6 +++---
>   gdb/dwarf2/attribute.h          |  4 ++--
>   gdb/dwarf2/call-site.h          |  2 +-
>   gdb/dwarf2/cooked-index-entry.h |  2 +-
>   gdb/dwarf2/die.h                |  2 +-
>   gdb/frame-id.h                  |  2 +-
>   gdb/gdbtypes.h                  | 14 +++++++-------
>   gdb/macrotab.h                  |  2 +-
>   gdb/symtab.h                    | 12 ++++++------
>   gdbsupport/packed.h             |  4 ++--
>   11 files changed, 26 insertions(+), 26 deletions(-)
>
> diff --git a/gdb/cli/cli-decode.h b/gdb/cli/cli-decode.h
> index 865f89ed9b5..49384f4a04d 100644
> --- a/gdb/cli/cli-decode.h
> +++ b/gdb/cli/cli-decode.h
> @@ -177,7 +177,7 @@ struct cmd_list_element
>   
>     /* Type of "set" or "show" command (or SET_NOT_SET if not "set"
>        or "show").  */
> -  ENUM_BITFIELD (cmd_types) type : 2;
> +  cmd_types type : 2;
>   
>     /* Function definition of this command.  NULL for command class
>        names and for help topics that are not really commands.  NOTE:
> diff --git a/gdb/dwarf2/abbrev.h b/gdb/dwarf2/abbrev.h
> index c5a3c6c39a6..78ad1e164ad 100644
> --- a/gdb/dwarf2/abbrev.h
> +++ b/gdb/dwarf2/abbrev.h
> @@ -34,8 +34,8 @@
>   
>   struct attr_abbrev
>   {
> -  ENUM_BITFIELD(dwarf_attribute) name : 16;
> -  ENUM_BITFIELD(dwarf_form) form : 16;
> +  dwarf_attribute name : 16;
> +  dwarf_form form : 16;
>   
>     /* It is valid only if FORM is DW_FORM_implicit_const.  */
>     LONGEST implicit_const;
> @@ -47,7 +47,7 @@ struct abbrev_info
>     /* Number identifying abbrev.  */
>     unsigned int number;
>     /* DWARF tag.  */
> -  ENUM_BITFIELD (dwarf_tag) tag : 16;
> +  dwarf_tag tag : 16;
>     /* True if the DIE has children.  */
>     bool has_children;
>     bool interesting;
> diff --git a/gdb/dwarf2/attribute.h b/gdb/dwarf2/attribute.h
> index 776ce43825d..f2648747d9c 100644
> --- a/gdb/dwarf2/attribute.h
> +++ b/gdb/dwarf2/attribute.h
> @@ -338,7 +338,7 @@ struct attribute
>        will issue a complaint and return false.  */
>     bool as_boolean () const;
>   
> -  ENUM_BITFIELD(dwarf_attribute) name : 15;
> +  dwarf_attribute name : 15;
>   
>     /* A boolean that is used for forms that require reprocessing.  A
>        form may require data not directly available in the attribute.
> @@ -351,7 +351,7 @@ struct attribute
>        forms.  */
>     unsigned int requires_reprocessing : 1;
>   
> -  ENUM_BITFIELD(dwarf_form) form : 15;
> +  dwarf_form form : 15;
>   
>     /* Has u.str already been updated by dwarf2_canonicalize_name?  This
>        field should be in u.str but it is kept here for better struct
> diff --git a/gdb/dwarf2/call-site.h b/gdb/dwarf2/call-site.h
> index e5519721390..5e2e270e383 100644
> --- a/gdb/dwarf2/call-site.h
> +++ b/gdb/dwarf2/call-site.h
> @@ -152,7 +152,7 @@ struct call_site_parameter
>     gdb::array_view<const gdb_byte> data_value_expr () const
>     { return gdb::make_array_view (data_value, data_value_size); }
>   
> -  ENUM_BITFIELD (call_site_parameter_kind) kind : 2;
> +  call_site_parameter_kind kind : 2;
>   
>     union call_site_parameter_u u;
>   
> diff --git a/gdb/dwarf2/cooked-index-entry.h b/gdb/dwarf2/cooked-index-entry.h
> index 9f7a7c42de4..60ea581cbbe 100644
> --- a/gdb/dwarf2/cooked-index-entry.h
> +++ b/gdb/dwarf2/cooked-index-entry.h
> @@ -267,7 +267,7 @@ struct cooked_index_entry : public allocate_on_obstack<cooked_index_entry>
>        situation where the language is initially unknown, and then only
>        filled in later.  In particular this can happen when using
>        .gdb_index.  See also cooked_index_functions::search.  */
> -  mutable ENUM_BITFIELD (language) lang : LANGUAGE_BITS;
> +  mutable language lang : LANGUAGE_BITS;
>     /* The offset of this DIE.  */
>     sect_offset die_offset;
>     /* The CU from which this entry originates.  This may point to a
> diff --git a/gdb/dwarf2/die.h b/gdb/dwarf2/die.h
> index c5f8a8e89f1..a8bc147b1c8 100644
> --- a/gdb/dwarf2/die.h
> +++ b/gdb/dwarf2/die.h
> @@ -114,7 +114,7 @@ struct die_info
>     }
>   
>     /* DWARF-2 tag for this DIE.  */
> -  ENUM_BITFIELD(dwarf_tag) tag : 16;
> +  dwarf_tag tag : 16;
>   
>     /* Number of attributes */
>     unsigned char num_attrs;
> diff --git a/gdb/frame-id.h b/gdb/frame-id.h
> index 50de31133a6..677b159b26b 100644
> --- a/gdb/frame-id.h
> +++ b/gdb/frame-id.h
> @@ -95,7 +95,7 @@ struct frame_id
>     CORE_ADDR special_addr;
>   
>     /* Flags to indicate the above fields have valid contents.  */
> -  ENUM_BITFIELD(frame_id_stack_status) stack_status : 3;
> +  frame_id_stack_status stack_status : 3;
>     unsigned int code_addr_p : 1;
>     unsigned int special_addr_p : 1;
>   
> diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
> index b32056ce530..027b814fe6a 100644
> --- a/gdb/gdbtypes.h
> +++ b/gdb/gdbtypes.h
> @@ -756,7 +756,7 @@ struct field
>   
>     /* * Discriminant for union field_location.  */
>   
> -  ENUM_BITFIELD(field_loc_kind) m_loc_kind : 3;
> +  field_loc_kind m_loc_kind : 3;
>   
>     /* Accessibility of the field.  */
>     enum accessibility m_accessibility;
> @@ -902,7 +902,7 @@ struct main_type
>   {
>     /* * Code for kind of type.  */
>   
> -  ENUM_BITFIELD(type_code) code : 8;
> +  type_code code : 8;
>   
>     /* * Flags about this type.  These fields appear at this location
>        because they packs nicely here.  See the TYPE_* macros for
> @@ -942,11 +942,11 @@ struct main_type
>     /* * A discriminant telling us which field of the type_specific
>        union is being used for this type, if any.  */
>   
> -  ENUM_BITFIELD(type_specific_kind) type_specific_field : 3;
> +  type_specific_kind type_specific_field : 3;
>   
>     /* The language for this type.  */
>   
> -  ENUM_BITFIELD(language) m_lang : LANGUAGE_BITS;
> +  language m_lang : LANGUAGE_BITS;
>   
>     /* * Number of fields described for this type.  This field appears
>        at this location because it packs nicely here.  */
> @@ -1667,7 +1667,7 @@ struct fn_field
>     /* * DW_AT_defaulted attribute for this function.  The value is one
>        of the DW_DEFAULTED constants.  */
>   
> -  ENUM_BITFIELD (dwarf_defaulted_attribute) defaulted : 2;
> +  dwarf_defaulted_attribute defaulted : 2;
>   
>     /* Accessibility of the field.  */
>     enum accessibility accessibility;
> @@ -1745,7 +1745,7 @@ struct cplus_struct_type
>          DW_AT_calling_convention attribute.  The value is one of the
>          DW_CC constants.  */
>   
> -    ENUM_BITFIELD (dwarf_calling_convention) calling_convention : 8;
> +    dwarf_calling_convention calling_convention : 8;
>   
>       /* * The base class which defined the virtual function table pointer.  */
>   
> @@ -1821,7 +1821,7 @@ struct func_type
>          DW_AT_calling_convention attribute.  The value is one of the
>          DW_CC constants.  */
>   
> -    ENUM_BITFIELD (dwarf_calling_convention) calling_convention : 8;
> +    dwarf_calling_convention calling_convention : 8;
>   
>       /* * Whether this function normally returns to its caller.  It is
>          set from the DW_AT_noreturn attribute if set on the
> diff --git a/gdb/macrotab.h b/gdb/macrotab.h
> index 4e66c7ac915..1a4c46a1cb1 100644
> --- a/gdb/macrotab.h
> +++ b/gdb/macrotab.h
> @@ -291,7 +291,7 @@ struct macro_definition
>     struct macro_table *table;
>   
>     /* What kind of macro it is.  */
> -  ENUM_BITFIELD (macro_kind) kind : 1;
> +  macro_kind kind : 1;
>   
>     /* If `kind' is `macro_function_like', the number of arguments it
>        takes, and their names.  The names, and the array of pointers to
> diff --git a/gdb/symtab.h b/gdb/symtab.h
> index 5a3db47d84f..0a7ad3668b4 100644
> --- a/gdb/symtab.h
> +++ b/gdb/symtab.h
> @@ -404,11 +404,11 @@ typedef bool (symbol_name_matcher_ftype)
>        struct partial_symbol
>   
>      These structures are laid out to encourage good packing.
> -   They use ENUM_BITFIELD and short int fields, and they order the
> +   They use bitfields and short int fields, and they order the
>      structure members so that fields less than a word are next
>      to each other so they can be packed together.  */
>   
> -/* Rearranged: used ENUM_BITFIELD and rearranged field order in
> +/* Rearranged: used bitfields and rearranged field order in
>      all the space critical structures (plus struct minimal_symbol).
>      Memory usage dropped from 99360768 bytes to 90001408 bytes.
>      I measured this with before-and-after tests of
> @@ -586,7 +586,7 @@ struct general_symbol_info
>        This is used to select one of the fields from the language specific
>        union above.  */
>   
> -  ENUM_BITFIELD(language) m_language : LANGUAGE_BITS;
> +  enum language m_language : LANGUAGE_BITS;
>   
>     /* This is only used by Ada.  If set, then the 'demangled_name' field
>        of language_specific is valid.  Otherwise, the 'obstack' field is
> @@ -815,7 +815,7 @@ struct minimal_symbol : public general_symbol_info
>   
>     /* Classification type for this minimal symbol.  */
>   
> -  ENUM_BITFIELD(minimal_symbol_type) m_type : MINSYM_TYPE_BITS;
> +  minimal_symbol_type m_type : MINSYM_TYPE_BITS;
>   
>     /* Non-zero if this symbol was created by gdb.
>        Such symbols do not appear in the output of "info var|fun".  */
> @@ -1468,7 +1468,7 @@ struct symbol : public general_symbol_info, public allocate_on_obstack<symbol>
>   
>     /* Domain code.  */
>   
> -  ENUM_BITFIELD(domain_enum) m_domain : SYMBOL_DOMAIN_BITS;
> +  domain_enum m_domain : SYMBOL_DOMAIN_BITS;
>   
>     /* Location class.  This holds an index into the 'symbol_impls'
>        table.  The actual location_class value is stored there,
> @@ -1498,7 +1498,7 @@ struct symbol : public general_symbol_info, public allocate_on_obstack<symbol>
>   
>     /* The concrete type of this symbol.  */
>   
> -  ENUM_BITFIELD (symbol_subclass_kind) subclass : 2;
> +  symbol_subclass_kind subclass : 2;
>   
>     /* Whether this symbol is artificial.  */
>   
> diff --git a/gdbsupport/packed.h b/gdbsupport/packed.h
> index 16564d5312e..70ffb712e19 100644
> --- a/gdbsupport/packed.h
> +++ b/gdbsupport/packed.h
> @@ -25,8 +25,8 @@
>      defines a type that behaves like a given scalar type, but that has
>      byte alignment, and, may optionally have a smaller size than the
>      given scalar type.  This is typically used as alternative to
> -   bit-fields (and ENUM_BITFIELD), when the fields must have separate
> -   memory locations to avoid data races.  */
> +   bit-fields, when the fields must have separate memory locations to
> +   avoid data races.  */
>   
>   /* There are two implementations here -- one standard compliant, using
>      a byte array for internal representation, and another that relies