From 0a69d9bdc70e90bac8211099e950826b6999b75a Mon Sep 17 00:00:00 2001 From: Eric Botcazou Date: Mon, 1 May 2017 08:12:31 +0000 Subject: [PATCH] decl.c (components_to_record): Add more comments. * gcc-interface/decl.c (components_to_record): Add more comments. Put back pending fields onto the regular list if the misalignment happens to cancel itself. From-SVN: r247426 --- gcc/ada/ChangeLog | 6 ++++++ gcc/ada/gcc-interface/decl.c | 13 ++++++++++++- 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog index 6c9b9474cfd..1b80de8ef35 100644 --- a/gcc/ada/ChangeLog +++ b/gcc/ada/ChangeLog @@ -1,3 +1,9 @@ +2017-05-01 Eric Botcazou + + * gcc-interface/decl.c (components_to_record): Add more comments. + Put back pending fields onto the regular list if the misalignment + happens to cancel itself. + 2017-04-28 Ed Schonberg * sem_ch4.adb (Complete_Object_Operation): When rewriting the diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c index 0c9c78ac10a..c243d40d17b 100644 --- a/gcc/ada/gcc-interface/decl.c +++ b/gcc/ada/gcc-interface/decl.c @@ -7956,6 +7956,10 @@ components_to_record (Node_Id gnat_component_list, Entity_Id gnat_record_type, different kinds of fields and issue a warning if some of them would be (or are being) reordered by the reordering mechanism. + Finally, pull out the fields whose size is not a multiple of a byte, so + that they don't cause the regular fields to be misaligned. As this can + only happen in packed record types, the alignment is capped to the byte. + ??? If we reorder them, debugging information will be wrong but there is nothing that can be done about this at the moment. */ const bool do_reorder = OK_To_Reorder_Components (gnat_record_type); @@ -8155,8 +8159,15 @@ components_to_record (Node_Id gnat_component_list, Entity_Id gnat_record_type, in_variant, do_reorder); if (do_reorder) { + /* If we have pending bit-packed fields on the temporary list, we put + them either on the bit-packed list or back on the regular list. */ if (gnu_tmp_bitp_list) - gnu_bitp_list = chainon (gnu_tmp_bitp_list, gnu_bitp_list); + { + if (tmp_bitp_size != 0) + gnu_bitp_list = chainon (gnu_tmp_bitp_list, gnu_bitp_list); + else + gnu_field_list = chainon (gnu_tmp_bitp_list, gnu_field_list); + } gnu_field_list = chainon (gnu_field_list, -- 2.30.2