Re: [PATCH 3/5] RISC-V: Add linux target support.

Andrew Burgess
2018-08-08T14:41:59Z

* Jim Wilson <jimw@sifive.com> [2018-08-07 19:16:38 -0700]:

> Add initial target support for riscv*-linux*.
>
> gdb/
> * riscv-linux-tdep.c: New file.

This seems fine to me, with a couple of minor issues...

> ---
> gdb/riscv-linux-tdep.c | 88 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 88 insertions(+)
> create mode 100644 gdb/riscv-linux-tdep.c
>
> diff --git a/gdb/riscv-linux-tdep.c b/gdb/riscv-linux-tdep.c
> new file mode 100644
> index 0000000000..c98dba70ca
> --- /dev/null
> +++ b/gdb/riscv-linux-tdep.c
> @@ -0,0 +1,88 @@
> +/* Target-dependent code for GNU/Linux on RISC-V processors.
> + Copyright (C) 2018 Free Software Foundation, Inc.
> +
> + This file is part of GDB.
> +
> + This program is free software; you can redistribute it and/or modify
> + it under the terms of the GNU General Public License as published by
> + the Free Software Foundation; either version 3 of the License, or
> + (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
> +
> +#include "defs.h"
> +#include "riscv-tdep.h"
> +#include "osabi.h"
> +#include "glibc-tdep.h"
> +#include "linux-tdep.h"
> +#include "solib-svr4.h"
> +#include "regset.h"
> +
> +static const struct regcache_map_entry riscv_linux_gregmap[] =
> +{
> + { 1, RISCV_PC_REGNUM, 0 },
> + { 31, RISCV_RA_REGNUM, 0 }, /* x1 to x31 */
> + { 0 }
> +};
> +
> +const struct regset riscv_linux_gregset =
> +{
> + riscv_linux_gregmap, regcache_supply_regset, regcache_collect_regset
> +};

Could this not be static?

Also, I think 'riscv_linux_gregmap' and 'riscv_linux_gregset' should
both have comments against them, I'm pretty sure the expectation these
days is that every definition has a comment....

Otherwise, this looks great,

Thanks,
Andrew

> +
> +/* Define hook for core file support. */
> +
> +static void
> +riscv_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
> + iterate_over_regset_sections_cb *cb,
> + void *cb_data,
> + const struct regcache *regcache)
> +{
> + cb (".reg", (32 * riscv_isa_xlen (gdbarch)),
> + &riscv_linux_gregset, NULL, cb_data);
> +
> + /* TODO: Add FP register support. */
> +}
> +
> +/* Initialize RISC-V Linux ABI info. */
> +
> +static void
> +riscv_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> +{
> + linux_init_abi (info, gdbarch);
> +
> + set_gdbarch_software_single_step (gdbarch, riscv_software_single_step);
> +
> + set_solib_svr4_fetch_link_map_offsets (gdbarch,
> + (riscv_isa_xlen (gdbarch) == 4
> + ? svr4_ilp32_fetch_link_map_offsets
> + : svr4_lp64_fetch_link_map_offsets));
> +
> + /* GNU/Linux uses SVR4-style shared libraries. */
> + set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
> +
> + /* GNU/Linux uses the dynamic linker included in the GNU C Library. */
> + set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
> +
> + /* Enable TLS support. */
> + set_gdbarch_fetch_tls_load_module_address (gdbarch,
> + svr4_fetch_objfile_link_map);
> +
> + set_gdbarch_iterate_over_regset_sections
> + (gdbarch, riscv_linux_iterate_over_regset_sections);
> +}
> +
> +/* Initialize RISC-V Linux target support. */
> +
> +void
> +_initialize_riscv_linux_tdep (void)
> +{
> + gdbarch_register_osabi (bfd_arch_riscv, 0, GDB_OSABI_LINUX,
> + riscv_linux_init_abi);
> +}
> --
> 2.17.1
>