From: Simon Marchi <simon.marchi@polymtl.ca>
Date: Sat, 26 Jun 2021 01:38:51 +0000 (-0400)
Subject: gdb: add assert in cmd_list_element::set_context
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d6ff04a343f97026f7d23bb036e0f858b21f3bfd;p=binutils-gdb.git

gdb: add assert in cmd_list_element::set_context

If something tries to set a context pointer on a cmd_list_element and
m_context is not nullptr, it's likely that two parts of the code are
trying to set different contexts, and one will overwrite the other.
This is almost guaranteed to lead to bad behavior or a crash, as one of
the spots will not be using the data it expects.  This happened to me
during development, so I think having this assert would be useful to
catch this problem earlier.

gdb/ChangeLog:

	* cli/cli-decode.h (struct cmd_list_element) <set_context>: Add
	assert.

Change-Id: I1f2e9fda1bf2bec1b732c9b90e7d7910a97f2ac6
---

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index c523186cdd7..6ba91d8ec6e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2021-06-25  Simon Marchi  <simon.marchi@polymtl.ca>
+
+	* cli/cli-decode.h (struct cmd_list_element) <set_context>: Add
+	assert.
+
 2021-06-25  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* cli/cli-decode.h (struct cmd_list_element) <set_context,
diff --git a/gdb/cli/cli-decode.h b/gdb/cli/cli-decode.h
index 1692a6e2835..241535ae5b5 100644
--- a/gdb/cli/cli-decode.h
+++ b/gdb/cli/cli-decode.h
@@ -94,7 +94,10 @@ struct cmd_list_element
   { return this->func == nullptr; }
 
   void set_context (void *context)
-  { m_context = context; }
+  {
+    gdb_assert (m_context == nullptr);
+    m_context = context;
+  }
 
   void *context () const
   { return m_context; }