[PATCH, v2] Improve load command's help text

[Luis Machado <lgustavo at codesourcery dot com>]

Changes in v2:

- Improved description of how FILE and OFFSET must be passed.
- Complemented description in the GDB manual since it was missing the
  description for OFFSET.

This fairly obvious patch adds usage text to the load command's help text.

Originally it did not have usage and mentioned things like FILE and OFFSET
without explaining how those should be passed in the command.

gdb/ChangeLog:

2017-01-06  Luis Machado  <lgustavo@codesourcery.com>

	* symfile (_initialize_symfile): Add usage text to the load command's
	help text.

gdb/doc/ChangeLog:

2017-01-06  Luis Machado  <lgustavo@codesourcery.com>

	* gdb.texinfo (_initialize_symfile): Document the optional offset
	argument.
---
 gdb/doc/gdb.texinfo | 8 ++++++--
 gdb/symfile.c       | 5 ++++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index ccb95ad..d9c77f7 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -19591,8 +19591,8 @@ Show the current status of displaying communications between
 
 @table @code
 
-@kindex load @var{filename}
-@item load @var{filename}
+@kindex load @var{filename} @var{offset}
+@item load @var{filename} @var{offset}
 @anchor{load}
 Depending on what remote debugging facilities are configured into
 @value{GDBN}, the @code{load} command may be available.  Where it exists, it
@@ -19611,6 +19611,10 @@ link the program; for other formats, like a.out, the object file format
 specifies a fixed address.
 @c FIXME! This would be a good place for an xref to the GNU linker doc.
 
+It is also possible to tell @value{GDBN} to load the symbol file at a specific
+offset described by the optional argument @var{offset}.  When @var{offset} is
+provided, @var{filename} must also be provided.
+
 Depending on the remote side capabilities, @value{GDBN} may be able to
 load programs into flash memory.
 
diff --git a/gdb/symfile.c b/gdb/symfile.c
index 61b9e5b..6ffc86b 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -3952,7 +3952,10 @@ that lies within the boundaries of this symbol file in memory."),
   c = add_cmd ("load", class_files, load_command, _("\
 Dynamically load FILE into the running program, and record its symbols\n\
 for access from GDB.\n\
-A load OFFSET may also be given."), &cmdlist);
+An optional load OFFSET may also be given as a literal address.\n\
+When OFFSET is provided, FILE must also be provided.  FILE can be provided\n\
+on its own.\n\
+Usage: load [FILE] [OFFSET]"), &cmdlist);
   set_cmd_completer (c, filename_completer);
 
   add_prefix_cmd ("overlay", class_support, overlay_command,
-- 
2.7.4