Excerpts from Iain Buclaw's message of April 15, 2025 3:32 pm:
> Hi,
>
> This patch fixes the ICE in PR119799.
>
> This was caused by a check in the D front-end disallowing static
> VAR_DECLs with a size `0'.
>
> While empty structs in D are given the size `1', the same symbol coming
> from ImportC modules do infact have no size, so allow C variables to
> pass the check as well as array objects.
>
> Bootstrapped and regression tested on x86_64-linux-gnu/-m32, and
> committed to mainline. Will backport as necessary once gcc-14/13/12
> release branches have been regtested too.
>
FYI,
This patch has been backported to releases/gcc-13 and gcc-14.
Regards,
Iain.
> ---
> PR d/119799
>
> gcc/d/ChangeLog:
>
> * decl.cc (DeclVisitor::visit (VarDeclaration *)): Check front-end
> type size before building the VAR_DECL. Allow C symbols to have a
> size of `0'.
>
> gcc/testsuite/ChangeLog:
>
> * gdc.dg/import-c/pr119799.d: New test.
> * gdc.dg/import-c/pr119799c.c: New test.
> ---
> gcc/d/decl.cc | 15 ++++++++++-----
> gcc/testsuite/gdc.dg/import-c/pr119799.d | 2 ++
> gcc/testsuite/gdc.dg/import-c/pr119799c.c | 1 +
> 3 files changed, 13 insertions(+), 5 deletions(-)
> create mode 100644 gcc/testsuite/gdc.dg/import-c/pr119799.d
> create mode 100644 gcc/testsuite/gdc.dg/import-c/pr119799c.c
>
> diff --git a/gcc/d/decl.cc b/gcc/d/decl.cc
> index 136f78b32ff..9ddf7cf1540 100644
> --- a/gcc/d/decl.cc
> +++ b/gcc/d/decl.cc
> @@ -791,6 +791,12 @@ public:
> }
> else if (d->isDataseg ())
> {
> + /* When the front-end type size is invalid, an error has already been
> + given for the declaration or type. */
> + dinteger_t size = dmd::size (d->type, d->loc);
> + if (size == SIZE_INVALID)
> + return;
> +
> tree decl = get_symbol_decl (d);
>
> /* Only need to build the VAR_DECL for extern declarations. */
> @@ -804,9 +810,7 @@ public:
> return;
>
> /* How big a symbol can be should depend on back-end. */
> - tree size = build_integer_cst (dmd::size (d->type, d->loc),
> - build_ctype (Type::tsize_t));
> - if (!valid_constant_size_p (size))
> + if (!valid_constant_size_p (build_integer_cst (size, size_type_node)))
> {
> error_at (make_location_t (d->loc), "size is too large");
> return;
> @@ -835,8 +839,9 @@ public:
> }
>
> /* Frontend should have already caught this. */
> - gcc_assert (!integer_zerop (size)
> - || d->type->toBasetype ()->isTypeSArray ());
> + gcc_assert ((size != 0 && size != SIZE_INVALID)
> + || d->type->toBasetype ()->isTypeSArray ()
> + || d->isCsymbol ());
>
> d_finish_decl (decl);
>
> diff --git a/gcc/testsuite/gdc.dg/import-c/pr119799.d
> b/gcc/testsuite/gdc.dg/import-c/pr119799.d
> new file mode 100644
> index 00000000000..d8b0fa22fe1
> --- /dev/null
> +++ b/gcc/testsuite/gdc.dg/import-c/pr119799.d
> @@ -0,0 +1,2 @@
> +// { dg-do compile }
> +import pr119799c;
> diff --git a/gcc/testsuite/gdc.dg/import-c/pr119799c.c
> b/gcc/testsuite/gdc.dg/import-c/pr119799c.c
> new file mode 100644
> index 00000000000..b80e856f75f
> --- /dev/null
> +++ b/gcc/testsuite/gdc.dg/import-c/pr119799c.c
> @@ -0,0 +1 @@
> +static struct {} s119799;
> --
> 2.43.0
>
>
