https://gcc.gnu.org/g:a1adc5aa30caae043cbd45dbbf9a738bebba34cc
commit r16-7124-ga1adc5aa30caae043cbd45dbbf9a738bebba34cc Author: Iain Buclaw <[email protected]> Date: Wed Jan 28 22:09:37 2026 +0100 d: Fix ICE: in output_constructor_regular_field, at varasm.cc:5500 [PR123798] PR d/123798 gcc/d/ChangeLog: * types.cc (insert_aggregate_bitfield): Set DECL_NONADDRESSABLE_P and DECL_PADDING_P on bit-field decls. (finish_aggregate_type): Pass the aligned bit offset to layout_decl. gcc/testsuite/ChangeLog: * gdc.dg/pr123798.d: New test. Diff: --- gcc/d/types.cc | 10 +++++++++- gcc/testsuite/gdc.dg/pr123798.d | 14 ++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/gcc/d/types.cc b/gcc/d/types.cc index 81b42b4615f9..e6f1bcbb9047 100644 --- a/gcc/d/types.cc +++ b/gcc/d/types.cc @@ -324,6 +324,10 @@ insert_aggregate_bitfield (tree type, tree bitfield, size_t width, DECL_BIT_FIELD (bitfield) = 1; DECL_BIT_FIELD_TYPE (bitfield) = TREE_TYPE (bitfield); + DECL_NONADDRESSABLE_P (bitfield) = 1; + if (DECL_NAME (bitfield) == NULL_TREE) + DECL_PADDING_P (bitfield) = 1; + TYPE_FIELDS (type) = chainon (TYPE_FIELDS (type), bitfield); } @@ -671,7 +675,11 @@ finish_aggregate_type (unsigned structsize, unsigned alignsize, tree type) continue; } - layout_decl (field, 0); + /* Layout the field decl using its known alignment. */ + unsigned int known_align = + least_bit_hwi (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (field))); + + layout_decl (field, known_align); /* Give bit-field its proper type after layout_decl. */ if (DECL_BIT_FIELD (field)) diff --git a/gcc/testsuite/gdc.dg/pr123798.d b/gcc/testsuite/gdc.dg/pr123798.d new file mode 100644 index 000000000000..92f8c2daec1e --- /dev/null +++ b/gcc/testsuite/gdc.dg/pr123798.d @@ -0,0 +1,14 @@ +// { dg-do compile } +// { dg-additional-options "-fpreview=bitfields" } +class C123798 +{ + int a : 4; + long b : 8; +} + +struct S123798 +{ + int a = 1; + int b : 4; + long c : 8; +}
