RISC-V/Linux/native: Factor out target description determination

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.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 8080c47932cbb567e00950a19199baaf7137c84f..8ea4ea55f7ca87111ed051c9d3f81ad12470c57b 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2020-02-05  Maciej W. Rozycki  <macro@wdc.com>
+
+       * 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.
+
 2020-02-04  Andrew Burgess  <andrew.burgess@embecosm.com>
 
        * remote-sim.c (sim_inferior_data::sim_inferior_data): Assert that

diff --git a/gdb/configure.nat b/gdb/configure.nat
index fb4522f5799b802737056e42629ef57ca3c1c08c..3fc6f5cb4a2525e29879070e7aebbd365b48b356 100644 (file)
--- a/gdb/configure.nat
+++ b/gdb/configure.nat
@@ -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

diff --git a/gdb/nat/riscv-linux-tdesc.c b/gdb/nat/riscv-linux-tdesc.c
new file mode 100644 (file)
index 0000000..1b625cf
--- /dev/null
+++ b/gdb/nat/riscv-linux-tdesc.c
@@ -0,0 +1,83 @@
+/* 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 FP data register.  */
+      regset_size = ELF_NFPREG * flen;
+      if (regset_size > sizeof (regs))
+       break;
+
+      iov.iov_base = &regs;
+      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);
+}

diff --git a/gdb/nat/riscv-linux-tdesc.h b/gdb/nat/riscv-linux-tdesc.h
new file mode 100644 (file)
index 0000000..9b57a9e
--- /dev/null
+++ b/gdb/nat/riscv-linux-tdesc.h
@@ -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 */

diff --git a/gdb/riscv-linux-nat.c b/gdb/riscv-linux-nat.c
index 043bbd44b6825e0291f8d5c610fcd0fc8d0e5a8a..2622f1b4399576c54b88da2ad79b693f662d5569 100644 (file)
--- a/gdb/riscv-linux-nat.c
+++ b/gdb/riscv-linux-nat.c
@@ -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.  */
@@ -200,53 +201,7 @@ fill_fpregset (const struct regcache *regcache, prfpregset_t *fpregs,
 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 FP data register.  */
-      regset_size = ELF_NFPREG * flen;
-      if (regset_size > sizeof (regs))
-       break;
-
-      iov.iov_base = &regs;
-      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