On 9/28/21 2:31 PM, Qing Zhao via Gcc-patches wrote:
Hi,
This is the patch for the gcc12 changes per your request.
Kees provided most of the wording.
Please take a look and let’s know whether it’s good for commit?
thanks.
Qing
================================================
From: qing zhao <qing.z...@oracle.com>
Date: Tue, 28 Sep 2021 12:01:42 -0700
Subject: [PATCH] gcc-12/changes.html: Uninitialized stack variables
initialization update
* htdocs/gcc-12/changes.html (Eliminating uninitialized variables):
Item about the support for automatic static variable initialization.
---
htdocs/gcc-12/changes.html | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/htdocs/gcc-12/changes.html b/htdocs/gcc-12/changes.html
index 1f156a9..8e2979c 100644
--- a/htdocs/gcc-12/changes.html
+++ b/htdocs/gcc-12/changes.html
@@ -245,6 +245,25 @@ a work-in-progress.</p>
<!-- .................................................................. -->
<h2>Other significant improvements</h2>
+<h3 id="uninitialized">Eliminating uninitialized variables</h3>
+
+<ul>
+ <li>GCC can now initialize all stack variables implicitly, including
+ padding. This is intended to eliminate all classes of uninitialized
+ stack variable flaws. Lack of explicit initialization will still
+ warn when <code>-Wuninitialized</code> is active. For best
+ debugging, use of the new command-line option
+ <code>-ftrivial-auto-var-init=pattern</code> can be used to fill
+ variables with a repeated 0xFE pattern, which tends to illuminate
+ many bugs (e.g. pointers receive invalid addresses, sizes and indices
+ are very large). For best production results, the new command-line
+ option <code>-ftrivial-auto-var-init=zero</code> can be used to
+ fill variables with 0x00, which tends to provide a safer state for
+ bugs (e.g. pointers are NULL, strings are NULL filled, and sizes
+ and indices are 0).
The "use ... can be used" in the sentence
For best debugging, use of the new command-line option
-ftrivial-auto-var-init=pattern can be used...
reads a bit awkward. Following the phrasing of the second such
sentence would look better:
To aid in debugging, the new command-line option
-ftrivial-auto-var-init=pattern can be used...
Martin
+ </li>
+</ul>
+
<h3 id="debug">Debugging formats</h3>
<ul>
