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Posted to dev@subversion.apache.org by Gabriela Gibson <ga...@gmail.com> on 2013/05/06 13:48:53 UTC
[PATCH] HACKING GUIDE entry for SVN_DBG usage in the Debugging Subversion
section
Hi,
I created a short SVN_DBG overview for the debugging page in the
HACKING GUIDE.
Please let me know if this can be improved.
Gabriela
[[[
Add section describing usage of the SVN_DBG macro to the Community Guide
page 'Debugging Subversion'.
* publish/docs/community-guide/debugging.part.html
(svn_dbg): Provide overview, links, hints and sample patches.
* publish/docs/community-guide/debugging.toc.html
(): Add link to section svn_dbg.
Suggested by: danielsh
]]]
(Just the raw text for ease of reading)
-------------------------------------------------------------------
Debugging with SVN_DBG
The SVN_DBG debugging tool is a C Preprocessor macro that sends
debugging output to stdout (by default) or stderr whilst not
interfering with the SVN test suite.
It provides an alternative to a debugger such as gdb, or
alternatively, extra information to assist in the use of a
debugger. It might be especially useful in situations where a
debugger cannot be used.
The svn_debug module contains two debug aid macros that print the
file:line of the call and printf-like arguments to the
#SVN_DBG_OUTPUT stdio stream (#stdout by default):
SVN_DBG( ( const char *fmt, ...) ) /* double braces are neccessary */
and
SVN_DBG_PROPS( ( apr_hash_t *props, const char *header_fmt, ...) )
Controlling SVN_DBG output:
* SVN_DBG is enabled whenever svn is configured with
--enable-maintainer-mode.
* The SVN test suite turns off SVN_DBG output automatically, to
suppress the output manually, set the SVN_DBG_QUIET variable
to 1 in your shell environment.
* When you are done, please be sure to remove any instances of
the SVN_DBG and SVN_DBG_PROPS macros from any code you are
committing and from any patch that you send to the
list. (AKA: Do not forget a scalpel in the patient!)
The SVN_DBG macro definitions and code are located in:
* subversion/include/private/svn_debug.h
* subversion/libsvn_subr/debug.c
Sample patch showing usage of the SVN_DBG macro:
Index: subversion/libsvn_fs_fs/fs_fs.c
===================================================================
--- subversion/libsvn_fs_fs/fs_fs.c (revision 1476635)
+++ subversion/libsvn_fs_fs/fs_fs.c (working copy)
@@ -2303,6 +2303,9 @@ get_node_revision_body(node_revision_t **noderev_p
/* First, try a cache lookup. If that succeeds, we are done here. */
SVN_ERR(get_cached_node_revision_body(noderev_p, fs, id, &is_cached,
pool));
+ SVN_DBG(("Getting %s from: %s\n",
+ svn_fs_fs__id_unparse(id),
+ is_cached ? "cache" : "disk"));
if (is_cached)
return SVN_NO_ERROR;
Sample patch showing usage of the SVN_DBG_PROPS macro:
Index: subversion/svn/proplist-cmd.c
===================================================================
--- subversion/svn/proplist-cmd.c(revision 1475745)
+++ subversion/svn/proplist-cmd.c(working copy)
@@ -221,6 +221,7 @@ svn_cl__proplist(apr_getopt_t *os,
URL, &(opt_state->start_revision),
&rev, ctx, scratch_pool));
+ /* this can be called with svn proplist --revprop -r <rev> */
+ SVN_DBG_PROPS((proplist,"The variable apr_hash_t *proplist
contains: "));
if (opt_state->xml)
{
svn_stringbuf_t *sb = NULL;
Re: [PATCH] HACKING GUIDE entry for SVN_DBG usage in the Debugging
Subversion section
Posted by Stefan Sperling <st...@elego.de>.
On Mon, May 06, 2013 at 12:48:53PM +0100, Gabriela Gibson wrote:
> Hi,
>
> I created a short SVN_DBG overview for the debugging page in the
> HACKING GUIDE.
>
> Please let me know if this can be improved.
+1 to commit. Thanks! This is very useful for new contributors.