Generate c for feature instead of tdesc

gdb:

2017-06-13  Yao Qi  <yao.qi@linaro.org>
:
	* NEWS
gdb/doc:

2017-06-13  Yao Qi  <yao.qi@linaro.org>
:
	* gdb.texinfo (Print the entire architecture configuration.  The optional argument):

2 files changed, 8 insertions, 4 deletions

diff --git a/gdb/NEWS b/gdb/NEWS
index 7c8a8f6..9cd1df1 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -17,6 +17,9 @@
 QStartupWithShell
   Indicates whether the inferior must be started with a shell or not.
 
+* The "maintenance print c-tdesc" command now takes an optional
+  argument which is the file name of XML target description.
+
 * New commands
 
 set debug separate-debug-file
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index b78d8ac..04d344e 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -34690,10 +34690,11 @@ Print the entire architecture configuration.  The optional argument
 @kindex maint print c-tdesc @r{[}@var{file}@r{]}
 @item maint print c-tdesc
 Print the target description (@pxref{Target Descriptions}) as
-a C source file.  The target description is got from the optional
-argument @var{file} or the current target description.  The created
-source file can be used in @value{GDBN} when an XML parser is not
-available to parse the description.
+a C source file.  By default, the target description is for the current
+target, but if the optional argument @var{file} is provided, that file
+is used to produce the description.  The @var{file} should be an XML
+document, of the form described in @ref{Target Description Format}.
+The created source file is built into @value{GDBN}.
 
 @kindex maint print dummy-frames
 @item maint print dummy-frames