[9/10] RFC: implement the $_exception convenience variable

[Tom Tromey]

>>>>> "Eli" == Eli Zaretskii <eliz@gnu.org> writes:

Tom> This patch introduces a new $_exception convenience variable, which is
Tom> valid at exception catchpoints.  The libstdc++ SDT probes are needed for
Tom> this, as only they expose the information needed to compute the
Tom> exception object -- namely, a pointer to the data, and also the
Tom> corresponding std::type_info object.

Eli> Can we tell somewhere in the docs starting with which version of
Eli> libstdc++ this will work?

Sure, how about this?

Tom

	* gdb.texinfo (Set Catchpoints): Mention earliest version of
	GCC that has the SDT probe points.
---
 gdb/doc/gdb.texinfo | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 337837e..47b1188 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -4101,6 +4101,9 @@ supported.
 The regular expression feature and the @code{$_exception} convenience
 variable rely on the presence of some SDT probes in @code{libstdc++}.
 If these probes are not present, then these features cannot be used.
+These probes were first available in the GCC 4.8 release, but whether
+or not they are available in your GCC also depends on how it was
+built.
 
 @item
 The @code{$_exception} convenience variable is only valid at the
-- 
1.8.1.4