[RFC][PATCH] - Fix pretty-printers which call the inferiors, mi-interface crashs

[RFC][PATCH] - Fix pretty-printers which call the inferiors, mi-interface crashs

[Vörtler, Thilo]

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Hi,
as described in Bug 17437 the mi interface corrupts cached frames in
the list_arg_or_local function of mi-cmd-stack.c when a pretty-printer
calls a function of the inferior. To prevent this the frame_id is stored
and used to restore the frame after calling list_arg_or_local
- MI regressions were run and no effect through the patch was seen

Is this patch okay?

BR, Thilo


gdb/ChangeLog:

2016-06-02  Thilo Vörtler  <thilo.voertler@coseda-tech.com>

	* mi-cmd-stack.c (list_args_or_locals) the mi interface corrupts 
	cached frames in the list_arg_or_local function of mi-cmd-stack.c when
	a pretty-printer calls a function of the inferior. To prevent this the 
	frame_id is stored and used to restore the frame after calling 
	list_arg_or_local

[-- Attachment #2: 0001-FIX-pretty-printers-which-call-the-inferiors-though-.patch --]
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From 1bd73a4b39fcbe31362c57a6d2e0392018a62435 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thilo=20V=C3=B6rtler?= <thilo.voertler@coseda-tech.com>
Date: Wed, 1 Jun 2016 15:16:57 +0200
Subject: [PATCH] FIX pretty-printers which call the inferiors though the mi-interface

- as described in Bug 17437 the mi interface corrupts cached frames in
the list_arg_or_local function of mi-cmd-stack.c when a pretty-printer
calls a function of the inferior. To prevent this the frame_id is stored
and used to restore the frame after calling list_arg_or_local
- MI regressions were run and no effect through the patch was seen
---
 gdb/mi/mi-cmd-stack.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/gdb/mi/mi-cmd-stack.c b/gdb/mi/mi-cmd-stack.c
index 390fc7e..5622834 100644
--- a/gdb/mi/mi-cmd-stack.c
+++ b/gdb/mi/mi-cmd-stack.c
@@ -581,8 +581,10 @@ list_args_or_locals (enum what_to_list what, enum print_values values,
   struct type *type;
   char *name_of_result;
   struct ui_out *uiout = current_uiout;
+  struct frame_id id;
 
   block = get_frame_block (fi, 0);
+  id = get_frame_id (fi);
 
   switch (what)
     {
@@ -680,6 +682,8 @@ list_args_or_locals (enum what_to_list what, enum print_values values,
 		list_arg_or_local (&entryarg, what, values, skip_unavailable);
 	      xfree (arg.error);
 	      xfree (entryarg.error);
+
+	      fi = frame_find_by_id(id);
 	    }
 	}
 
-- 
1.7.1