binutils-gdb/gdb/inf-child.c
Yao Qi bdca27a2f5 Use readlink unconditionally
Since readlink module is imported, we can use it unconditionally.
This patch is to remove configure checks and HAVE_READLINK checks in
code.  It was mentioned in the patch below

  [RFA/commit] gdbserver: return ENOSYS if readlink not supported.
  https://sourceware.org/ml/gdb-patches/2012-02/msg00148.html

to use readlink in gdbserver, but we chose something simple at that
moment.

gdb:

2014-11-28  Yao Qi  <yao@codesourcery.com>

	* configure.ac (AC_CHECK_FUNCS): Remove readlink.
	* config.in, configure: Re-generate.
	* inf-child.c (inf_child_fileio_readlink): Don't check
	HAVE_READLINK is defined.

gdb/gdbserver:

2014-11-28  Yao Qi  <yao@codesourcery.com>

	* configure.ac(AC_CHECK_FUNCS): Remove readlink.
	* config.in, configure: Re-generate.
	* hostio.c (handle_unlink): Remove code checking HAVE_READLINK
	is defined.
2014-11-28 18:37:52 +08:00

516 lines
14 KiB
C

/* Base/prototype target for default child (native) targets.
Copyright (C) 1988-2014 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/>. */
/* This file provides a common base class/target that all native
target implementations extend, by calling inf_child_target to get a
new prototype target and then overriding target methods as
necessary. */
#include "defs.h"
#include "regcache.h"
#include "memattr.h"
#include "symtab.h"
#include "target.h"
#include "inferior.h"
#include <sys/stat.h>
#include "inf-child.h"
#include "gdb/fileio.h"
#include "agent.h"
#include "gdb_wait.h"
#include "filestuff.h"
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
/* A pointer to what is returned by inf_child_target. Used by
inf_child_open to push the most-derived target in reaction to
"target native". */
static struct target_ops *inf_child_ops = NULL;
/* Helper function for child_wait and the derivatives of child_wait.
HOSTSTATUS is the waitstatus from wait() or the equivalent; store our
translation of that in OURSTATUS. */
void
store_waitstatus (struct target_waitstatus *ourstatus, int hoststatus)
{
if (WIFEXITED (hoststatus))
{
ourstatus->kind = TARGET_WAITKIND_EXITED;
ourstatus->value.integer = WEXITSTATUS (hoststatus);
}
else if (!WIFSTOPPED (hoststatus))
{
ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (hoststatus));
}
else
{
ourstatus->kind = TARGET_WAITKIND_STOPPED;
ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (hoststatus));
}
}
/* Fetch register REGNUM from the inferior. If REGNUM is -1, do this
for all registers. */
static void
inf_child_fetch_inferior_registers (struct target_ops *ops,
struct regcache *regcache, int regnum)
{
if (regnum == -1)
{
for (regnum = 0;
regnum < gdbarch_num_regs (get_regcache_arch (regcache));
regnum++)
regcache_raw_supply (regcache, regnum, NULL);
}
else
regcache_raw_supply (regcache, regnum, NULL);
}
/* Store register REGNUM back into the inferior. If REGNUM is -1, do
this for all registers (including the floating point registers). */
static void
inf_child_store_inferior_registers (struct target_ops *ops,
struct regcache *regcache, int regnum)
{
}
static void
inf_child_post_attach (struct target_ops *self, int pid)
{
/* This target doesn't require a meaningful "post attach" operation
by a debugger. */
}
/* Get ready to modify the registers array. On machines which store
individual registers, this doesn't need to do anything. On
machines which store all the registers in one fell swoop, this
makes sure that registers contains all the registers from the
program being debugged. */
static void
inf_child_prepare_to_store (struct target_ops *self,
struct regcache *regcache)
{
}
/* True if the user did "target native". In that case, we won't
unpush the child target automatically when the last inferior is
gone. */
static int inf_child_explicitly_opened;
/* See inf-child.h. */
void
inf_child_open_target (struct target_ops *target, const char *arg,
int from_tty)
{
target_preopen (from_tty);
push_target (target);
inf_child_explicitly_opened = 1;
if (from_tty)
printf_filtered ("Done. Use the \"run\" command to start a process.\n");
}
static void
inf_child_open (const char *arg, int from_tty)
{
inf_child_open_target (inf_child_ops, arg, from_tty);
}
/* Implement the to_disconnect target_ops method. */
static void
inf_child_disconnect (struct target_ops *target, const char *args, int from_tty)
{
if (args != NULL)
error (_("Argument given to \"disconnect\"."));
/* This offers to detach/kill current inferiors, and then pops all
targets. */
target_preopen (from_tty);
}
/* Implement the to_close target_ops method. */
static void
inf_child_close (struct target_ops *target)
{
/* In case we were forcibly closed. */
inf_child_explicitly_opened = 0;
}
void
inf_child_mourn_inferior (struct target_ops *ops)
{
generic_mourn_inferior ();
inf_child_maybe_unpush_target (ops);
}
/* See inf-child.h. */
void
inf_child_maybe_unpush_target (struct target_ops *ops)
{
if (!inf_child_explicitly_opened && !have_inferiors ())
unpush_target (ops);
}
static void
inf_child_post_startup_inferior (struct target_ops *self, ptid_t ptid)
{
/* This target doesn't require a meaningful "post startup inferior"
operation by a debugger. */
}
static int
inf_child_follow_fork (struct target_ops *ops, int follow_child,
int detach_fork)
{
/* This target doesn't support following fork or vfork events. */
return 0;
}
static int
inf_child_can_run (struct target_ops *self)
{
return 1;
}
static char *
inf_child_pid_to_exec_file (struct target_ops *self, int pid)
{
/* This target doesn't support translation of a process ID to the
filename of the executable file. */
return NULL;
}
/* Target file operations. */
static int
inf_child_fileio_open_flags_to_host (int fileio_open_flags, int *open_flags_p)
{
int open_flags = 0;
if (fileio_open_flags & ~FILEIO_O_SUPPORTED)
return -1;
if (fileio_open_flags & FILEIO_O_CREAT)
open_flags |= O_CREAT;
if (fileio_open_flags & FILEIO_O_EXCL)
open_flags |= O_EXCL;
if (fileio_open_flags & FILEIO_O_TRUNC)
open_flags |= O_TRUNC;
if (fileio_open_flags & FILEIO_O_APPEND)
open_flags |= O_APPEND;
if (fileio_open_flags & FILEIO_O_RDONLY)
open_flags |= O_RDONLY;
if (fileio_open_flags & FILEIO_O_WRONLY)
open_flags |= O_WRONLY;
if (fileio_open_flags & FILEIO_O_RDWR)
open_flags |= O_RDWR;
/* On systems supporting binary and text mode, always open files in
binary mode. */
#ifdef O_BINARY
open_flags |= O_BINARY;
#endif
*open_flags_p = open_flags;
return 0;
}
static int
inf_child_errno_to_fileio_error (int errnum)
{
switch (errnum)
{
case EPERM:
return FILEIO_EPERM;
case ENOENT:
return FILEIO_ENOENT;
case EINTR:
return FILEIO_EINTR;
case EIO:
return FILEIO_EIO;
case EBADF:
return FILEIO_EBADF;
case EACCES:
return FILEIO_EACCES;
case EFAULT:
return FILEIO_EFAULT;
case EBUSY:
return FILEIO_EBUSY;
case EEXIST:
return FILEIO_EEXIST;
case ENODEV:
return FILEIO_ENODEV;
case ENOTDIR:
return FILEIO_ENOTDIR;
case EISDIR:
return FILEIO_EISDIR;
case EINVAL:
return FILEIO_EINVAL;
case ENFILE:
return FILEIO_ENFILE;
case EMFILE:
return FILEIO_EMFILE;
case EFBIG:
return FILEIO_EFBIG;
case ENOSPC:
return FILEIO_ENOSPC;
case ESPIPE:
return FILEIO_ESPIPE;
case EROFS:
return FILEIO_EROFS;
case ENOSYS:
return FILEIO_ENOSYS;
case ENAMETOOLONG:
return FILEIO_ENAMETOOLONG;
}
return FILEIO_EUNKNOWN;
}
/* Open FILENAME on the target, using FLAGS and MODE. Return a
target file descriptor, or -1 if an error occurs (and set
*TARGET_ERRNO). */
static int
inf_child_fileio_open (struct target_ops *self,
const char *filename, int flags, int mode,
int *target_errno)
{
int nat_flags;
int fd;
if (inf_child_fileio_open_flags_to_host (flags, &nat_flags) == -1)
{
*target_errno = FILEIO_EINVAL;
return -1;
}
/* We do not need to convert MODE, since the fileio protocol uses
the standard values. */
fd = gdb_open_cloexec (filename, nat_flags, mode);
if (fd == -1)
*target_errno = inf_child_errno_to_fileio_error (errno);
return fd;
}
/* Write up to LEN bytes from WRITE_BUF to FD on the target.
Return the number of bytes written, or -1 if an error occurs
(and set *TARGET_ERRNO). */
static int
inf_child_fileio_pwrite (struct target_ops *self,
int fd, const gdb_byte *write_buf, int len,
ULONGEST offset, int *target_errno)
{
int ret;
#ifdef HAVE_PWRITE
ret = pwrite (fd, write_buf, len, (long) offset);
#else
ret = -1;
#endif
/* If we have no pwrite or it failed for this file, use lseek/write. */
if (ret == -1)
{
ret = lseek (fd, (long) offset, SEEK_SET);
if (ret != -1)
ret = write (fd, write_buf, len);
}
if (ret == -1)
*target_errno = inf_child_errno_to_fileio_error (errno);
return ret;
}
/* Read up to LEN bytes FD on the target into READ_BUF.
Return the number of bytes read, or -1 if an error occurs
(and set *TARGET_ERRNO). */
static int
inf_child_fileio_pread (struct target_ops *self,
int fd, gdb_byte *read_buf, int len,
ULONGEST offset, int *target_errno)
{
int ret;
#ifdef HAVE_PREAD
ret = pread (fd, read_buf, len, (long) offset);
#else
ret = -1;
#endif
/* If we have no pread or it failed for this file, use lseek/read. */
if (ret == -1)
{
ret = lseek (fd, (long) offset, SEEK_SET);
if (ret != -1)
ret = read (fd, read_buf, len);
}
if (ret == -1)
*target_errno = inf_child_errno_to_fileio_error (errno);
return ret;
}
/* Close FD on the target. Return 0, or -1 if an error occurs
(and set *TARGET_ERRNO). */
static int
inf_child_fileio_close (struct target_ops *self, int fd, int *target_errno)
{
int ret;
ret = close (fd);
if (ret == -1)
*target_errno = inf_child_errno_to_fileio_error (errno);
return ret;
}
/* Unlink FILENAME on the target. Return 0, or -1 if an error
occurs (and set *TARGET_ERRNO). */
static int
inf_child_fileio_unlink (struct target_ops *self,
const char *filename, int *target_errno)
{
int ret;
ret = unlink (filename);
if (ret == -1)
*target_errno = inf_child_errno_to_fileio_error (errno);
return ret;
}
/* Read value of symbolic link FILENAME on the target. Return a
null-terminated string allocated via xmalloc, or NULL if an error
occurs (and set *TARGET_ERRNO). */
static char *
inf_child_fileio_readlink (struct target_ops *self,
const char *filename, int *target_errno)
{
/* We support readlink only on systems that also provide a compile-time
maximum path length (PATH_MAX), at least for now. */
#if defined (PATH_MAX)
char buf[PATH_MAX];
int len;
char *ret;
len = readlink (filename, buf, sizeof buf);
if (len < 0)
{
*target_errno = inf_child_errno_to_fileio_error (errno);
return NULL;
}
ret = xmalloc (len + 1);
memcpy (ret, buf, len);
ret[len] = '\0';
return ret;
#else
*target_errno = FILEIO_ENOSYS;
return NULL;
#endif
}
static int
inf_child_use_agent (struct target_ops *self, int use)
{
if (agent_loaded_p ())
{
use_agent = use;
return 1;
}
else
return 0;
}
static int
inf_child_can_use_agent (struct target_ops *self)
{
return agent_loaded_p ();
}
/* Default implementation of the to_can_async_p and
to_supports_non_stop methods. */
static int
return_zero (struct target_ops *ignore)
{
return 0;
}
struct target_ops *
inf_child_target (void)
{
struct target_ops *t = XCNEW (struct target_ops);
t->to_shortname = "native";
t->to_longname = "Native process";
t->to_doc = "Native process (started by the \"run\" command).";
t->to_open = inf_child_open;
t->to_close = inf_child_close;
t->to_disconnect = inf_child_disconnect;
t->to_post_attach = inf_child_post_attach;
t->to_fetch_registers = inf_child_fetch_inferior_registers;
t->to_store_registers = inf_child_store_inferior_registers;
t->to_prepare_to_store = inf_child_prepare_to_store;
t->to_insert_breakpoint = memory_insert_breakpoint;
t->to_remove_breakpoint = memory_remove_breakpoint;
t->to_terminal_init = child_terminal_init;
t->to_terminal_inferior = child_terminal_inferior;
t->to_terminal_ours_for_output = child_terminal_ours_for_output;
t->to_terminal_ours = child_terminal_ours;
t->to_terminal_info = child_terminal_info;
t->to_post_startup_inferior = inf_child_post_startup_inferior;
t->to_follow_fork = inf_child_follow_fork;
t->to_can_run = inf_child_can_run;
/* We must default these because they must be implemented by any
target that can run. */
t->to_can_async_p = return_zero;
t->to_supports_non_stop = return_zero;
t->to_pid_to_exec_file = inf_child_pid_to_exec_file;
t->to_stratum = process_stratum;
t->to_has_all_memory = default_child_has_all_memory;
t->to_has_memory = default_child_has_memory;
t->to_has_stack = default_child_has_stack;
t->to_has_registers = default_child_has_registers;
t->to_has_execution = default_child_has_execution;
t->to_fileio_open = inf_child_fileio_open;
t->to_fileio_pwrite = inf_child_fileio_pwrite;
t->to_fileio_pread = inf_child_fileio_pread;
t->to_fileio_close = inf_child_fileio_close;
t->to_fileio_unlink = inf_child_fileio_unlink;
t->to_fileio_readlink = inf_child_fileio_readlink;
t->to_magic = OPS_MAGIC;
t->to_use_agent = inf_child_use_agent;
t->to_can_use_agent = inf_child_can_use_agent;
/* Store a pointer so we can push the most-derived target from
inf_child_open. */
inf_child_ops = t;
return t;
}