From: <apinski@marvell.com>
To: <gcc-patches@gcc.gnu.org>
Cc: Andrew Pinski <apinski@marvell.com>
Subject: [PATCH] [www] Add note about computed gotos to changes and porting guide
Date: Wed, 29 Sep 2021 01:15:14 -0700 [thread overview]
Message-ID: <1632903314-23720-1-git-send-email-apinski@marvell.com> (raw)
From: Andrew Pinski <apinski@marvell.com>
Even though there is not many computed gotos in the wild and even less
that would use an integer type, it would still be a good idea to add
this new error message to both changes and the porting to guide.
OK?
---
htdocs/gcc-12/changes.html | 6 ++--
htdocs/gcc-12/porting_to.html | 66 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 70 insertions(+), 2 deletions(-)
create mode 100644 htdocs/gcc-12/porting_to.html
diff --git a/htdocs/gcc-12/changes.html b/htdocs/gcc-12/changes.html
index 1f156a9..3130710 100644
--- a/htdocs/gcc-12/changes.html
+++ b/htdocs/gcc-12/changes.html
@@ -17,11 +17,9 @@
<p>
This page is a "brief" summary of some of the huge number of improvements
in GCC 12.
-<!--
You may also want to check out our
<a href="porting_to.html">Porting to GCC 12</a> page and the
<a href="../onlinedocs/index.html#current">full GCC documentation</a>.
--->
</p>
<p>Note: GCC 12 has not been released yet, so this document is
@@ -31,6 +29,10 @@ a work-in-progress.</p>
<h2>Caveats</h2>
<ul>
<li>
+ <strong>C:</strong>
+ Computed gotos require a pointer type now.
+ </li>
+ <li>
<strong>C++:</strong>
Two non-standard <code>std::pair</code> constructors have been deprecated.
These allowed the use of an rvalue and a literal <code>0</code> to
diff --git a/htdocs/gcc-12/porting_to.html b/htdocs/gcc-12/porting_to.html
new file mode 100644
index 0000000..9154d7b
--- /dev/null
+++ b/htdocs/gcc-12/porting_to.html
@@ -0,0 +1,66 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+<title>Porting to GCC 12</title>
+<link rel="stylesheet" type="text/css" href="https://gcc.gnu.org/gcc.css" />
+</head>
+
+<body>
+<h1>Porting to GCC 12</h1>
+
+<p>
+The GCC 12 release series differs from previous GCC releases in
+<a href="changes.html">a number of ways</a>. Some of these are a result
+of bug fixing, and some old behaviors have been intentionally changed
+to support new standards, or relaxed in standards-conforming ways to
+facilitate compilation or run-time performance.
+</p>
+
+<p>
+Some of these changes are user visible and can cause grief when
+porting to GCC 12. This document is an effort to identify common issues
+and provide solutions. Let us know if you have suggestions for improvements!
+</p>
+
+
+<!--
+<h2 id="cpp">Preprocessor issues</h2>
+-->
+<h2 id="c">C language issues</h2>
+
+<h3 id="computedgotos">Computed goto now require a pointer type</h3>
+
+<p>
+In GCC 12, computed gotos require a pointer type.
+An example which was accepted before:</p>
+<pre><code>
+ void f(void)
+ {
+ goto *10;
+ }
+</code></pre>
+is no longer accepted and you need to add a cast to it like:
+
+<pre><code>
+ void f(void)
+ {
+ goto *(void*)10;
+ }
+</code></pre>
+
+<!--
+<h2 id="cxx">C++ language issues</h2>
+-->
+
+<!--
+<h2 id="fortran">Fortran language issues</h2>
+-->
+
+<!--
+<h2 id="links">Links</h2>
+-->
+
+</body>
+</html>
--
1.8.3.1
next reply other threads:[~2021-09-29 8:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-29 8:15 apinski [this message]
2021-09-29 8:50 ` Richard Biener
2021-10-03 8:11 ` Gerald Pfeifer
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