Implement remote_pid_to_exec_file using qXfer:exec-file:read

This commit adds a new packet "qXfer:exec-file:read" to the remote
protocol that can be used to obtain the pathname of the file that
was executed to create a process on the remote system.  Support for
this packet is added to GDB and remote_ops.to_pid_to_exec_file is
implemented using it.

gdb/ChangeLog:

	* target.h (TARGET_OBJECT_EXEC_FILE): New enum value.
	* remote.c (PACKET_qXfer_exec_file): Likewise.
	(remote_protocol_features): Register the
	"qXfer:exec-file:read" feature.
	(remote_xfer_partial): Handle TARGET_OBJECT_EXEC_FILE.
	(remote_pid_to_exec_file): New function.
	(init_remote_ops): Initialize to_pid_to_exec_file.
	(_initialize_remote): Register new "set/show remote
	pid-to-exec-file-packet" command.
	* NEWS: Announce new qXfer:exec-file:read packet.

gdb/doc/ChangeLog:

	* gdb.texinfo (Remote Configuration): Document the "set/show
	remote pid-to-exec-file-packet" command.
	(General Query Packets): Document the qXfer:exec-file:read
	qSupported features.  Document the qXfer:exec-file:read packet.

1 files changed, 6 insertions, 1 deletions

diff --git a/gdb/target.h b/gdb/target.h
index f57e4316c86..66bf91ea4ba 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -204,7 +204,12 @@ enum target_object
   /* Branch trace data, in XML format.  */
   TARGET_OBJECT_BTRACE,
   /* Branch trace configuration, in XML format.  */
-  TARGET_OBJECT_BTRACE_CONF
+  TARGET_OBJECT_BTRACE_CONF,
+  /* The pathname of the executable file that was run to create
+     a specified process.  ANNEX should be a string representation
+     of the process ID of the process in question, in hexadecimal
+     format.  */
+  TARGET_OBJECT_EXEC_FILE,
   /* Possible future objects: TARGET_OBJECT_FILE, ...  */
 };