[v2,2/3] RISC-V/Linux/native: Factor out target description determination
Commit Message
In preparation for RISC-V/Linux `gdbserver' support factor out parts of
native target description determination code that can be shared between
the programs.
gdb/
* nat/riscv-linux-tdesc.h: New file.
* nat/riscv-linux-tdesc.c: New file, taking code from...
* riscv-linux-nat.c (riscv_linux_nat_target::read_description):
... here.
* configure.nat <linux> <riscv*>: Add nat/riscv-linux-tdesc.o to
NATDEPFILES.
---
New change in v2.
---
gdb/configure.nat | 3 +
gdb/nat/riscv-linux-tdesc.c | 82 ++++++++++++++++++++++++++++++++++++++++++++
gdb/nat/riscv-linux-tdesc.h | 27 ++++++++++++++
gdb/riscv-linux-nat.c | 50 +-------------------------
4 files changed, 114 insertions(+), 48 deletions(-)
gdb-riscv-linux-nat-tdesc.diff
Comments
On Wed, Jan 29, 2020 at 10:13 AM Maciej W. Rozycki <macro@wdc.com> wrote:
> gdb/
> * nat/riscv-linux-tdesc.h: New file.
> * nat/riscv-linux-tdesc.c: New file, taking code from...
> * riscv-linux-nat.c (riscv_linux_nat_target::read_description):
> ... here.
> * configure.nat <linux> <riscv*>: Add nat/riscv-linux-tdesc.o to
> NATDEPFILES.
Looks good to me, though I'm not an official reviewer.
Jim
===================================================================
@@ -276,7 +276,8 @@ case ${gdb_host} in
;;
riscv*)
# Host: RISC-V, running Linux
- NATDEPFILES="${NATDEPFILES} riscv-linux-nat.o"
+ NATDEPFILES="${NATDEPFILES} riscv-linux-nat.o \
+ nat/riscv-linux-tdesc.o"
;;
s390)
# Host: S390, running Linux
===================================================================
@@ -0,0 +1,82 @@
+/* GNU/Linux/RISC-V native target description support for GDB.
+ Copyright (C) 2020 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 "gdbsupport/common-defs.h"
+
+#include "gdb_proc_service.h"
+#include "arch/riscv.h"
+#include "elf/common.h"
+#include "nat/gdb_ptrace.h"
+#include "nat/riscv-linux-tdesc.h"
+
+#include <sys/uio.h>
+
+/* Work around glibc header breakage causing ELF_NFPREG not to be usable. */
+#ifndef NFPREG
+# define NFPREG 33
+#endif
+
+/* Determine XLEN and FLEN and return a corresponding target description. */
+
+const struct target_desc *
+riscv_linux_read_description (int tid)
+{
+ struct riscv_gdbarch_features features;
+ elf_fpregset_t regs;
+ int flen;
+
+ /* Figuring out xlen is easy. */
+ features.xlen = sizeof (elf_greg_t);
+
+ /* Start with no f-registers. */
+ features.flen = 0;
+
+ /* How much worth of f-registers can we fetch if any? */
+ for (flen = sizeof (regs.__f.__f[0]); ; flen *= 2)
+ {
+ size_t regset_size;
+ struct iovec iov;
+
+ /* Regsets have a uniform slot size, so we count FSCR like an FGR. */
+ regset_size = ELF_NFPREG * flen;
+ if (regset_size > sizeof (regs))
+ break;
+
+ iov.iov_base = ®s;
+ iov.iov_len = regset_size;
+ if (ptrace (PTRACE_GETREGSET, tid, NT_FPREGSET,
+ (PTRACE_TYPE_ARG3) &iov) == -1)
+ {
+ switch (errno)
+ {
+ case EINVAL:
+ continue;
+ case EIO:
+ break;
+ default:
+ perror_with_name (_("Couldn't get registers"));
+ break;
+ }
+ }
+ else
+ features.flen = flen;
+ break;
+ }
+
+ return riscv_create_target_description (features);
+}
===================================================================
@@ -0,0 +1,27 @@
+/* GNU/Linux/RISC-V native target description support for GDB.
+ Copyright (C) 2020 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/>. */
+
+#ifndef NAT_RISCV_LINUX_TDESC_H
+#define NAT_RISCV_LINUX_TDESC_H
+
+struct target_desc;
+
+/* Return a target description for the LWP identified by TID. */
+const struct target_desc *riscv_linux_read_description (int tid);
+
+#endif /* NAT_RISCV_LINUX_TDESC_H */
===================================================================
@@ -22,10 +22,11 @@
#include "linux-nat.h"
#include "riscv-tdep.h"
#include "inferior.h"
-#include "target-descriptions.h"
#include "elf/common.h"
+#include "nat/riscv-linux-tdesc.h"
+
#include <sys/ptrace.h>
/* Work around glibc header breakage causing ELF_NFPREG not to be usable. */
@@ -196,52 +197,7 @@ fill_fpregset (const struct regcache *re
const struct target_desc *
riscv_linux_nat_target::read_description ()
{
- struct riscv_gdbarch_features features;
- elf_fpregset_t regs;
- int flen;
- int tid;
-
- /* Figuring out xlen is easy. */
- features.xlen = sizeof (elf_greg_t);
-
- tid = inferior_ptid.lwp ();
-
- /* Start with no f-registers. */
- features.flen = 0;
-
- /* How much worth of f-registers can we fetch if any? */
- for (flen = sizeof (regs.__f.__f[0]); ; flen *= 2)
- {
- size_t regset_size;
- struct iovec iov;
-
- /* Regsets have a uniform slot size, so we count FSCR like an FGR. */
- regset_size = ELF_NFPREG * flen;
- if (regset_size > sizeof (regs))
- break;
-
- iov.iov_base = ®s;
- iov.iov_len = regset_size;
- if (ptrace (PTRACE_GETREGSET, tid, NT_FPREGSET,
- (PTRACE_TYPE_ARG3) &iov) == -1)
- {
- switch (errno)
- {
- case EINVAL:
- continue;
- case EIO:
- break;
- default:
- perror_with_name (_("Couldn't get registers"));
- break;
- }
- }
- else
- features.flen = flen;
- break;
- }
-
- return riscv_create_target_description (features);
+ return riscv_linux_read_description (inferior_ptid.lwp ());
}
/* Fetch REGNUM (or all registers if REGNUM == -1) from the target