[OE-core] gcc: Fix strange C++ repo issues

[Phil Blundell]

On Wed, 2013-10-09 at 23:11 +0100, Richard Purdie wrote:
> +++ b/meta/recipes-devtools/gcc/gcc-4.8/0047-repomembug.patch
> @@ -0,0 +1,46 @@
> +When compiling a project using -frepo, .rpo files are written alongside
> +the .o file, the symbols either have O or C against them. During final linking,
> +the objects can be recompiled with some of the entries tweaked/chosen by the 
> +tlink.c code (visible with TLINK_VERBOSE=3).
> +
> +My tests showed that init_repo (cp/repo.c) was correcting calling 
> +IDENTIFIER_REPO_CHOSEN against the right identifers.
> +
> +By the time finish_repo() or emit_repo_p() were called, the pointer returned
> +by get_identifier() for the symbol marked during init_repo had changed and
> +the chosen bit was no longer set. This lead to linking bugs like:
> +
> +collect: relinking
> +collect2: error: '_ZNK6sudoku5ClearINS_8SequenceEEclERS1_' was assigned to 'board.rpo', but was not defined during recompilation, or vice versa
> +
> +The problem is that the garbage collection is getting called before
> +finish_repo() is called and ggc_protect_identifiers is set to false 
> +so the identifiers are not preserved. They are recreated but the 
> +chosen bits get wiped out.
> +
> +The fix is to change ggc_protect_identifiers *after* the finish_repo 
> +calls are made.
> +
> +Reproduction is tricky since you need to trigger the garbage collector at
> +just the right moment.
> +
> +RP 2013/10/9
> +
> +Index: gcc-4.8.1/gcc/toplev.c

This patch header seems to lack an Upstream-Status.

p.