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[PATCH] Move vgdb special case into remote_filesystem_is_local
- From: Gary Benson <gbenson at redhat dot com>
- To: gdb-patches at sourceware dot org
- Date: Mon, 27 Apr 2015 15:51:16 +0100
- Subject: [PATCH] Move vgdb special case into remote_filesystem_is_local
- Authentication-results: sourceware.org; auth=none
Hi all,
Valgrind GDB (vgdb) presents itself as a remote target but works on
the local filesystem. gdb_bfd_open contained a special case to make
vgdb work with "target:" sysroots, but the implementation meant that
GDB would fall back to the local filesystem if *any* to_fileio_open
method failed with ENOSYS for *any* reason. This commit moves the
vgdb special case to remote_filesystem_is_local to allow the fallback
to be restricted only to the specific case that remote file transfer
is unsupported. This commit also adds a warning which is displayed
the first time the fallback is used.
Built and regtested on RHEL6.6 x86_64.
Ok to commit?
Cheers,
Gary
gdb/ChangeLog:
* gdb_bfd.c (gdb_bfd_open): Move vgdb special case to...
* remote.c (remote_filesystem_is_local): ...here.
---
gdb/ChangeLog | 5 ++++
gdb/gdb_bfd.c | 16 +-------------
gdb/remote.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++--------
3 files changed, 59 insertions(+), 24 deletions(-)
diff --git a/gdb/gdb_bfd.c b/gdb/gdb_bfd.c
index 3d5d23f..2cd91ef 100644
--- a/gdb/gdb_bfd.c
+++ b/gdb/gdb_bfd.c
@@ -326,25 +326,11 @@ gdb_bfd_open (const char *name, const char *target, int fd)
{
gdb_assert (fd == -1);
- abfd = gdb_bfd_openr_iovec (name, target,
+ return gdb_bfd_openr_iovec (name, target,
gdb_bfd_iovec_fileio_open, NULL,
gdb_bfd_iovec_fileio_pread,
gdb_bfd_iovec_fileio_close,
gdb_bfd_iovec_fileio_fstat);
-
- if (abfd != NULL || errno != ENOSYS)
- return abfd;
-
- /* gdb_bfd_iovec_fileio_open failed with ENOSYS. This can
- happen, for example, with vgdb (Valgrind GDB), which
- presents itself as a remote target but works on the local
- filesystem: it does not implement remote get and users
- are not expected to set gdb_sysroot. To handle this case
- we fall back to trying the local filesystem iff
- gdb_sysroot is exactly TARGET_SYSROOT_PREFIX. */
- if (gdb_sysroot == NULL
- || strcmp (gdb_sysroot, TARGET_SYSROOT_PREFIX) != 0)
- return NULL;
}
name += strlen (TARGET_SYSROOT_PREFIX);
diff --git a/gdb/remote.c b/gdb/remote.c
index 3b2325f..099ddbb 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -9879,15 +9879,6 @@ remote_hostio_send_command (int command_bytes, int which_packet,
return ret;
}
-/* Return nonzero if the filesystem accessed by the target_fileio_*
- methods is the local filesystem, zero otherwise. */
-
-static int
-remote_filesystem_is_local (struct target_ops *self)
-{
- return 0;
-}
-
/* Open FILENAME on the remote target, using FLAGS and MODE. Return a
remote file descriptor, or -1 if an error occurs (and set
*REMOTE_ERRNO). */
@@ -10125,6 +10116,59 @@ remote_hostio_fstat (struct target_ops *self,
return 0;
}
+/* Return nonzero if the filesystem accessed by the target_fileio_*
+ methods is the local filesystem, zero otherwise. */
+
+static int
+remote_filesystem_is_local (struct target_ops *self)
+{
+ /* Valgrind GDB presents itself as a remote target but works
+ on the local filesystem: it does not implement remote get
+ and users are not expected to set a sysroot. To handle
+ this case we treat the remote filesystem as local if the
+ sysroot is exactly TARGET_SYSROOT_PREFIX and if the stub
+ does not support vFile:open. */
+ if (gdb_sysroot != NULL
+ && strcmp (gdb_sysroot, TARGET_SYSROOT_PREFIX) == 0)
+ {
+ enum packet_support ps = packet_support (PACKET_vFile_open);
+
+ if (ps == PACKET_SUPPORT_UNKNOWN)
+ {
+ int fd, remote_errno;
+
+ /* Try opening a file to probe support. The supplied
+ filename is irrelevant, we only care about whether
+ the stub recognizes the packet or not. */
+ fd = remote_hostio_open (self, "just probing",
+ FILEIO_O_RDONLY, 0700,
+ &remote_errno);
+
+ if (fd >= 0)
+ remote_hostio_close (self, fd, &remote_errno);
+
+ ps = packet_support (PACKET_vFile_open);
+ }
+
+ if (ps == PACKET_DISABLE)
+ {
+ static int warning_issued = 0;
+
+ if (!warning_issued)
+ {
+ warning (_("remote target does not support file"
+ " transfer, attempting to access files"
+ " from local filesystem."));
+ warning_issued = 1;
+ }
+
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
static int
remote_fileio_errno_to_host (int errnum)
{
--
1.7.1