On Wed, Nov 25, 2020 at 10:24:23AM +0100, Christophe Lyon via Gcc-patches wrote:
> On Thu, 12 Nov 2020 at 06:56, Jason Merrill via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> >
> > If DECL_INITIAL isn't set, we can't emit anything about the body of the
> > function, so add the declaration attribute.
> >
> > Tested x86_64-pc-linux-gnu, applying to trunk.
> >
> > gcc/ChangeLog:
> >
> > PR debug/97060
> > * dwarf2out.c (gen_subprogram_die): It's a declaration
> > if DECL_INITIAL isn't set.
> >
> > gcc/testsuite/ChangeLog:
> >
> > PR debug/97060
> > * gcc.dg/debug/dwarf2/pr97060.c: New test.
>
> The new test fails on arm / aarch64, at least on the gcc-10 branch.
> Can you check?
I guess that is because gcc 10 branch does not have Richard's
PR96383 r11-2455-gc6ef9d8d3f11221df1ea6358b8d4e79e42f074fb
changes, only trunk has that and the Fedora/RHEL gcc 10 rpms have
that change applied as a patch in the spec file. So the PR97060
fix is needed only on the trunk and in the Fedora/RHEL gcc 10 rpms.
Probably it won't hurt in GCC 10 if the testcase doesn't expect
the DW_AT_declaration.
> > diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
> > index bc32a17efcd..a5aaa6c34da 100644
> > --- a/gcc/dwarf2out.c
> > +++ b/gcc/dwarf2out.c
> > @@ -22849,6 +22849,7 @@ gen_subprogram_die (tree decl, dw_die_ref
> > context_die)
> > available.
> > */
> > int declaration = (current_function_decl != decl
> > + || (!DECL_INITIAL (decl) && !origin)
> > || class_or_namespace_scope_p (context_die));
> >
> > /* A declaration that has been previously dumped needs no
> > diff --git a/gcc/testsuite/gcc.dg/debug/dwarf2/pr97060.c
> > b/gcc/testsuite/gcc.dg/debug/dwarf2/pr97060.c
> > new file mode 100644
> > index 00000000000..c07b9046d9a
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.dg/debug/dwarf2/pr97060.c
> > @@ -0,0 +1,13 @@
> > +/* PR debug/97060 */
> > +/* { dg-do compile } */
> > +/* { dg-options "-g -dA" } */
> > +/* { dg-final { scan-assembler-times "DW_AT_declaration" 2 } } */
> > +
> > +extern int foo (unsigned int, unsigned int);
> > +
> > +int
> > +bar (void)
> > +{
> > + foo (1, 2);
> > + return 0;
> > +}
> >
> > base-commit: 7a9a5d1a61c7b8111557261a8d275a531812b50e
> > --
> > 2.18.4
> >
Jakub
