On Fri, Jan 03, 2025 at 05:18:55PM +0000, xxx wrote:
> From: yxj-github-437 <2457369...@qq.com>
>
> This patch attempts to fix an error when build module std. The reason for the
> error is __builrin_va_list (aka struct __va_list) is an internal linkage. so
> attempt to handle this builtin type by identifying whether
> DECL_SOURCE_LOCATION (entity)
> is BUILTINS_LOCATION.
>
Hi, thanks for the patch! I suspect this may not be sufficient to
completely avoid issues with the __gnuc_va_list type; in particular, if
it's internal linkage that may prevent it from being referred to in
other ways by inline functions in named modules (due to P1815).
Maybe a better approach would be to instead mark this builtin type as
TREE_PUBLIC (presumably in aarch64_build_builtin_va_list)?
Nathaniel
> /x/gcc-15.0.0/usr/bin/aarch64-linux-android-g++ -fmodules -std=c++23 -fPIC -O2
> -fsearch-include-path bits/std.cc -c
> /x/gcc-15.0.0/usr/lib/gcc/aarch64-linux-android/15.0.0/include/c++/bits/std.cc:3642:14:
> error: exporting ‘typedef __gnuc_va_list va_list’ that does not have external
> linkage
> 3642 | using std::va_list;
> | ^~~~~~~
> <built-in>: note: ‘struct __va_list’ declared here with internal linkage
>
> gcc:
> * cp/name-lookup.cc (check_can_export_using_decl): add identifying
> whether
> DECL_SOURCE_LOCATION (entity) is BUILTINS_LOCATION.
> ---
> gcc/cp/name-lookup.cc | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
> index 0e185d3ef42..73f3034adb4 100644
> --- a/gcc/cp/name-lookup.cc
> +++ b/gcc/cp/name-lookup.cc
> @@ -5225,7 +5225,7 @@ check_can_export_using_decl (tree binding)
> if (TREE_CODE (entity) == TYPE_DECL)
> {
> entity = TYPE_MAIN_DECL (TREE_TYPE (entity));
> - if (!entity)
> + if (!entity || DECL_SOURCE_LOCATION (entity) == BUILTINS_LOCATION)
> return true;
> }
>
> --
> 2.43.0
>
