Author: jingham
Date: Tue Feb 26 11:18:09 2019
New Revision: 354914
URL: http://llvm.org/viewvc/llvm-project?rev=354914&view=rev
Log:
Mention predicting exception catch at throw site
Modified:
lldb/trunk/docs/status/projects.rst
lldb/trunk/www/projects.html
Modified: lldb/trunk/docs/status/projects.rst
URL:
http://llvm.org/viewvc/llvm-project/lldb/trunk/docs/status/projects.rst?rev=354914&r1=354913&r2=354914&view=diff
==============================================================================
--- lldb/trunk/docs/status/projects.rst (original)
+++ lldb/trunk/docs/status/projects.rst Tue Feb 26 11:18:09 2019
@@ -394,3 +394,24 @@ remote memory and its function calling s
useful to unify these and make the IR interpreter -- both for LLVM and LLDB --
better. An alternate strategy would be simply to JIT into the current process
but have callbacks for non-stack memory access.
+
+Teach lldb to predict exception propagation at the throw site
+-------------------------------------------------------------
+
+There are a bunch of places in lldb where we need to know at the point where an
+exception is thrown, what frame will catch the exception.
+
+For instance, if an expression throws an exception, we need to know whether
the
+exception will be caught in the course of the expression evaluation. If so it
+would be safe to let the expression continue. But since we would destroy the
+state of the thread if we let the exception escape the expression, we
currently
+stop the expression evaluation if we see a throw. If we knew where it would be
+caught we could distinguish these two cases.
+
+Similarly, when you step over a call that throws, you want to stop at the
throw
+point if you know the exception will unwind past the frame you were stepping
in,
+but it would annoying to have the step abort every time an exception was
thrown.
+If we could predict the catching frame, we could do this right.
+
+And of course, this would be a useful piece of information to display when
stopped
+at a throw point.
Modified: lldb/trunk/www/projects.html
URL:
http://llvm.org/viewvc/llvm-project/lldb/trunk/www/projects.html?rev=354914&r1=354913&r2=354914&view=diff
==============================================================================
--- lldb/trunk/www/projects.html (original)
+++ lldb/trunk/www/projects.html Tue Feb 26 11:18:09 2019
@@ -467,6 +467,32 @@
access.
</p>
</li>
+ <li>
+ Teach lldb to predict exception
propagation at the throw site
+
+ <p>
+ There are a bunch of places in
lldb where we need to know at the point where an
+ exception is thrown, what
frame will catch the exception.
+ </p>
+ <p>
+ For instance, if an expression
throws an exception, we need to know whether the
+ exception will be caught in the
course of the expression evaluation. If so it
+ would be safe to let the
expression continue. But since we would destroy the
+ state of the thread if we let
the exception escape the expression, we currently
+ stop the expression evaluation
if we see a throw. If we knew where it would be
+ caught we could distinguish
these two cases.
+ </p>
+ <p>
+ Similarly, when you step over a
call that throws, you want to stop at the throw
+ point if you know the exception
will unwind past the frame you were stepping in,
+ but it would annoying to have
the step abort every time an exception was thrown.
+ If we could predict the catching
frame, we could do this right.
+ </p>
+ <p>
+ And of course, this would be a
useful piece of information to display when stopped
+ at a throw point.
+ </p>
+ </li>
</ol>
</div>
<div class="postfooter"></div>
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