[PATCH 3/4] GDB: Fix documentation for invoking GDBSERVER

John Darrington
2018-10-13T17:58:09Z

The documentation did not mention the possibility of invoking gdbserver
with the new connection forms such as tcp6:host:port. This change fixes
that.

gdb/doc/

* gdb.texinfo (Server): Tabulate the various permitted forms of the @var{comm}
metasyntactical variable. Include the unix:@var{host}:@var{socket} form as
one of them.
---
gdb/doc/gdb.texinfo | 60 +++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 44 insertions(+), 16 deletions(-)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 1e97d692b6..e3b62221cf 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -21097,9 +21097,19 @@ syntax is:
target> gdbserver @var{comm} @var{program} [ @var{args} @dots{} ]
@end smallexample

-@var{comm} is either a device name (to use a serial line), or a TCP
-hostname and portnumber, or @code{-} or @code{stdio} to use
-stdin/stdout of @code{gdbserver}.
+@code{gdbserver} waits passively for the host @value{GDBN} to communicate
+with it.
+
+@var{comm} may take several forms:
+
+@table @code
+@item @code{@var{device}}
+A serial line device.
+
+@item @code{-}
+@itemx @code{stdio}
+To use the stdin/stdout of @code{gdbserver}.
+
For example, to debug Emacs with the argument
@samp{foo.txt} and communicate with @value{GDBN} over the serial port
@file{/dev/com1}:
@@ -21108,8 +21118,27 @@ For example, to debug Emacs with the argument
target> gdbserver /dev/com1 emacs foo.txt
@end smallexample

-@code{gdbserver} waits passively for the host @value{GDBN} to communicate
-with it.
+The @code{stdio} connection is useful when starting @code{gdbserver}
+with ssh:
+
+@smallexample
+(gdb) target remote | ssh -T hostname gdbserver - hello
+@end smallexample
+
+The @samp{-T} option to ssh is provided because we don't need a remote pty,
+and we don't want escape-character handling. Ssh does this by default when
+a command is provided, the flag is provided to make it explicit.
+You could elide it if you want to.
+
+Programs started with stdio-connected gdbserver have @file{/dev/null} for
+@code{stdin}, and @code{stdout},@code{stderr} are sent back to gdb for
+display through a pipe connected to gdbserver.
+Both @code{stdout} and @code{stderr} use the same pipe.
+
+@item @code{@var{host}:@var{port}}
+@itemx @code{tcp:@var{host}:@var{port}}
+@itemx @code{tcp4:@var{host}:@var{port}}
+To use a @acronym{TCP} @acronym{IPv4} socket connection on port number @var{port}.

To use a TCP connection instead of a serial line:

@@ -21129,22 +21158,21 @@ conflicts with another service, @code{gdbserver} prints an error message
and exits.} You must use the same port number with the host @value{GDBN}
@code{target remote} command.

-The @code{stdio} connection is useful when starting @code{gdbserver}
-with ssh:
+
+@item @code{tcp6:@var{host}:@var{port}}
+To use a @acronym{TCP} @acronym{IPv6} socket connection on port number @var{port}.
+
+@item @code{unix:@var{host}:@var{local-socket}}
+To use a Unix domain socket. This will create a socket with the file
+system entry @var{local-socket} and listen on that. For example:

@smallexample
-(gdb) target remote | ssh -T hostname gdbserver - hello
+target> gdbserver unix:localhost:/tmp/gdb-socket0 emacs foo.txt
@end smallexample

-The @samp{-T} option to ssh is provided because we don't need a remote pty,
-and we don't want escape-character handling. Ssh does this by default when
-a command is provided, the flag is provided to make it explicit.
-You could elide it if you want to.
+@var{host} must either be the null string or the literal string @code{localhost}.
+@end table

-Programs started with stdio-connected gdbserver have @file{/dev/null} for
-@code{stdin}, and @code{stdout},@code{stderr} are sent back to gdb for
-display through a pipe connected to gdbserver.
-Both @code{stdout} and @code{stderr} use the same pipe.

@anchor{Attaching to a program}
@subsubsection Attaching to a Running Program
--
2.11.0