Attached is a small patch to extend the SVN_ERR macro with another
parameter, a cleanup statement, that is executed before the error
generated by EXPR (if not SVN_NO_ERROR) is returned. Also attached is
a log message.
I plan on using this in a test of svn_subst_translate_string2() in
which I need to reset the locale to whatever it was before the test
began. See:
http://thread.gmane.org/gmane.comp.version-control.subversion.devel/125782
[[[
Extend the SVN_ERR macro with another parameter, a cleanup statement, that is
executed before returning in case of error.
* subversion/include/svn_error.h
(SVN_ERR_EX): New macro. Similar to SVN_ERR, it accepts an additional
parameter for a cleanup statement to execute before returning an error.
(SVN_ERR): Expand to SVN_ERR_EX with the same expression, and a no-op for the
cleanup statement.
]]]
Index: subversion/include/svn_error.h
===================================================================
--- subversion/include/svn_error.h (revision 1070074)
+++ subversion/include/svn_error.h (working copy)
@@ -275,8 +275,8 @@ svn_handle_warning(FILE *stream,
/** A statement macro for checking error values.
*
- * Evaluate @a expr. If it yields an error, return that error from the
- * current function. Otherwise, continue.
+ * Evaluate @a expr. If it yields an error, execute the cleanup statement and
+ * return that error from the current function. Otherwise, continue.
*
* The <tt>do { ... } while (0)</tt> wrapper has no semantic effect,
* but it makes this macro syntactically equivalent to the expression
@@ -284,20 +284,31 @@ svn_handle_warning(FILE *stream,
*
* @code
* if (a)
- * SVN_ERR(some operation);
+ * SVN_ERR_EX(some operation, some statement);
* else
* foo;
* @endcode
*
* would not mean what they appear to.
+ *
+ * @since New in 1.7.
*/
-#define SVN_ERR(expr) \
+#define SVN_ERR_EX(expr, cleanup_stmt) \
do { \
svn_error_t *svn_err__temp = (expr); \
if (svn_err__temp) \
- return svn_error_return(svn_err__temp); \
+ { \
+ { cleanup_stmt ; } \
+ return svn_error_return(svn_err__temp); \
+ } \
} while (0)
+/** A statement macro for checking error values.
+ *
+ * Similar to SVN_ERR_EX except that the cleanup statement is a no-op.
+ */
+#define SVN_ERR(expr) SVN_ERR_EX(expr, ((void) 0))
+
/**
* A statement macro for returning error values.
*
