Re: [gold patch] Incremental 17/22: COPY relocations

[Ian Lance Taylor <iant at google dot com>]

Cary Coutant <ccoutant@google.com> writes:

> 2011-04-26 Cary Coutant  <ccoutant@google.com>
>
> 	* copy-relocs.cc (Copy_relocs::copy_reloc): Call make_copy_reloc
> 	instead of emit_copy_reloc.
> 	(Copy_relocs::emit_copy_reloc): Refactor.
> 	(Copy_relocs::make_copy_reloc): New function.
> 	(Copy_relocs::add_copy_reloc): Remove.
> 	* copy-relocs.h (Copy_relocs::emit_copy_reloc): Move to public
> 	section.
> 	(Copy_relocs::make_copy_reloc): New function.
> 	(Copy_relocs::add_copy_reloc): Remove.
> 	* gold.cc (queue_middle_tasks): Emit old COPY relocations from
> 	unchanged input files.
> 	* incremental-dump.cc (dump_incremental_inputs): Print "COPY" flag.
> 	* incremental.cc (Sized_incremental_binary::do_reserve_layout):
> 	Reserve BSS space for COPY relocations.
> 	(Sized_incremental_binary::do_emit_copy_relocs): New function.
> 	(Output_section_incremental_inputs::write_info_blocks): Record
> 	whether a symbol is copied from a shared object.
> 	(Sized_incr_dynobj::do_add_symbols): Record COPY relocations.
> 	* incremental.h
> 	(Incremental_input_entry_reader::get_output_symbol_index): Add
> 	is_copy parameter.
> 	(Incremental_binary::emit_copy_relocs): New function.
> 	(Incremental_binary::do_emit_copy_relocs): New function.
> 	(Sized_incremental_binary::Sized_incremental_binary): Initialize
> 	new data member.
> 	(Sized_incremental_binary::add_copy_reloc): New function.
> 	(Sized_incremental_binary::do_emit_copy_relocs): New function.
> 	(Sized_incremental_binary::Copy_reloc): New struct.
> 	(Sized_incremental_binary::Copy_relocs): New typedef.
> 	(Sized_incremental_binary::copy_relocs_): New data member.
> 	* symtab.cc (Symbol_table::add_from_incrobj): Change return type.
> 	* symtab.h (Symbol_table::add_from_incrobj): Change return type.
> 	* target.h (Sized_target::emit_copy_reloc): New function.
> 	* x86_64.cc (Target_x86_64::emit_copy_reloc): New function.


>  		if (sym->source() == Symbol::FROM_OBJECT
>  		    && sym->object() == obj
>  		    && sym->is_defined())
> -		  def_flag = 1U << 31;
> +		  def_flag = 2U << 30;
> +		else if (sym->is_copied_from_dynobj()
> +			 && this->symtab_->get_copy_source(sym) == dynobj)
> +		  def_flag = 3U << 30;

Let's give some names to 1U, 2U, 3U, and 30.

> -      *is_def = (output_symndx & (1U << 31)) != 0;
> -      return output_symndx & ((1U << 31) - 1);
> +      *is_def = (output_symndx >> 31) == 1;
> +      *is_copy = (output_symndx >> 30) == 3;
> +      return output_symndx & ((1U << 30) - 1);

This is kind of tricky considering how the bits are set; better to use a
switch on output_symndx >> 30, I think.

This is OK with those changes.

Thanks.


> (I split a couple of patches and added a couple, so the total patch
> count is now up to 22.)

Don't think I didn't notice that you're up to 25 now.

Ian