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doc/go1.3.html: mention cgo [0]byte bug fix fallout
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Fixes golang#7958.

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/91590044
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rsc committed May 20, 2014
1 parent 0c2a727 commit 7ef0eb1
Showing 1 changed file with 53 additions and 20 deletions.
73 changes: 53 additions & 20 deletions doc/go1.3.html
Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,8 @@ <h3 id="win2000">Removal of support for Windows 2000</h3>
<h3 id="dragonfly">Support for DragonFly BSD</h3>

<p>
Go 1.3 now includes experimental support for DragonFly BSD on the <code>amd64</code> (64-bit x86) and <code>386</code> (32-bit x86) architectures. It uses DragonFly BSD 3.6 or above.
Go 1.3 now includes experimental support for DragonFly BSD on the <code>amd64</code> (64-bit x86) and <code>386</code> (32-bit x86) architectures.
It uses DragonFly BSD 3.6 or above.
</p>

<h3 id="freebsd">Support for FreeBSD</h3>
Expand All @@ -52,8 +53,8 @@ <h3 id="freebsd">Support for FreeBSD</h3>
</p>

<p>
In concert with the switch to EABI syscalls for ARM platforms, Go 1.3 will run only on
FreeBSD 10. The x86 platforms, 386 and amd64, are unaffected.
In concert with the switch to EABI syscalls for ARM platforms, Go 1.3 will run only on FreeBSD 10.
The x86 platforms, 386 and amd64, are unaffected.
</p>

<h3 id="nacl">Support for Native Client</h3>
Expand Down Expand Up @@ -83,13 +84,15 @@ <h3 id="openbsd">Support for OpenBSD</h3>
<h3 id="plan9">Support for Plan 9</h3>

<p>
Go 1.3 now includes experimental support for Plan 9 on the <code>386</code> (32-bit x86) architecture. It requires the <code>Tsemacquire</code> syscall, which has been in Plan 9 since June, 2012.
Go 1.3 now includes experimental support for Plan 9 on the <code>386</code> (32-bit x86) architecture.
It requires the <code>Tsemacquire</code> syscall, which has been in Plan 9 since June, 2012.
</p>

<h3 id="solaris">Support for Solaris</h3>

<p>
Go 1.3 now includes experimental support for Solaris on the <code>amd64</code> (64-bit x86) architecture. It requires illumos, Solaris 11 or above.
Go 1.3 now includes experimental support for Solaris on the <code>amd64</code> (64-bit x86) architecture.
It requires illumos, Solaris 11 or above.
</p>

<h2 id="memory">Changes to the memory model</h2>
Expand Down Expand Up @@ -228,7 +231,8 @@ <h3 id="gocmd">Changes to the go command</h3>

<p>
Cross compiling with <a href="/cmd/cgo/"><code>cgo</code></a> enabled
is now supported. The CC_FOR_TARGET and CXX_FOR_TARGET environment
is now supported.
The CC_FOR_TARGET and CXX_FOR_TARGET environment
variables are used when running all.bash to specify the cross compilers
for C and C++ code, respectively.
</p>
Expand All @@ -238,11 +242,36 @@ <h3 id="gocmd">Changes to the go command</h3>
files (suffixed <code>.m</code>) through cgo.
</p>

<h3 id="cgo">Changes to cgo</h3>

<p>
The <a href="/cmd/cgo/"><code>cmd/cgo</code></a> command,
which processes <code>import "C"</code> declarations in Go packages,
has corrected a serious bug that may cause some packages to stop compiling.
Previously, all pointers to incomplete struct types translated to the Go type <code>*[0]byte</code>,
with the effect that the Go compiler could not diagnose passing one kind of struct pointer
to a function expecting another.
Go 1.3 corrects this mistake by translating each different
incomplete struct to a different named type.
However, some Go code took advantage of this bug to pass (for example) a <code>*C.FILE</code>
from one package to another.
This is not legal and no longer works: in general Go packages
should avoid exposing C types and names in their APIs.
</p>

<p>
<em>Updating</em>: Code confusing pointers to incomplete types or
passing them across package boundaries will no longer compile
and must be rewritten.
If the conversion is correct and must be preserved,
use an explicit conversion via <a href="/pkg/unsafe/#Pointer"><code>unsafe.Pointer</code></a>.
</p>

<h3 id="swig">SWIG 3.0 required for programs that use SWIG</h3>

<p>
For Go programs that use SWIG, SWIG version 3.0 is now required. The
<a href="/cmd/go"><code>cmd/go</code></a> command will now link the
For Go programs that use SWIG, SWIG version 3.0 is now required.
The <a href="/cmd/go"><code>cmd/go</code></a> command will now link the
SWIG generated object files directly into the binary, rather than
building and linking with a shared library.
</p>
Expand All @@ -252,8 +281,8 @@ <h3 id="gc_flag">Command-line flag parsing</h3>
<p>
In the gc tool chain, the assemblers now use the
same command-line flag parsing rules as the Go flag package, a departure
from the traditional Unix flag parsing. This may affect scripts that invoke
the tool directly.
from the traditional Unix flag parsing.
This may affect scripts that invoke the tool directly.
For example,
<code>go tool 6a -SDfoo</code> must now be written
<code>go tool 6a -S -D foo</code>.
Expand Down Expand Up @@ -304,7 +333,8 @@ <h2 id="performance">Performance</h2>
<li>
The regular expression package <a href="/pkg/regexp/"><code>regexp</code></a>
is now significantly faster for certain simple expressions due to the implementation of
a second, one-pass execution engine. The choice of which engine to use is automatic;
a second, one-pass execution engine.
The choice of which engine to use is automatic;
the details are hidden from the user.
</li>

Expand Down Expand Up @@ -364,7 +394,8 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>

<li>
The complex power function, <a href="/pkg/math/cmplx/#Pow"><code>Pow</code></a>,
now specifies the behavior when the first argument is zero. It was undefined before.
now specifies the behavior when the first argument is zero.
It was undefined before.
The details are in the <a href="/pkg/math/cmplx/#Pow">documentation for the function</a>.
</li>

Expand Down Expand Up @@ -406,16 +437,17 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
supports disabling HTTP keep-alive connections on the server
with <a href="/pkg/net/http/#Server.SetKeepAlivesEnabled"><code>Server.SetKeepAlivesEnabled</code></a>.
The default continues to be that the server does keep-alive (reuses
connections for multiple requests) by default. Only
resource-constrained servers or those in the process of graceful
connections for multiple requests) by default.
Only resource-constrained servers or those in the process of graceful
shutdown will want to disable them.
</li>

<li>
The <a href="/pkg/net/http/"><code>net/http</code></a> package adds an optional
<a href="/pkg/net/http/#Transport"><code>Transport.TLSHandshakeTimeout</code></a>
setting to cap the amount of time HTTP client requests will wait for
TLS handshakes to complete. It's now also set by default
TLS handshakes to complete.
It's now also set by default
on <a href="/pkg/net/http#DefaultTransport"><code>DefaultTransport</code></a>.
</li>

Expand All @@ -424,8 +456,8 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
<a href="/pkg/net/http/#DefaultTransport"><code>DefaultTransport</code></a>,
used by the HTTP client code, now
enables <a href="http://en.wikipedia.org/wiki/Keepalive#TCP_keepalive">TCP
keep-alives</a> by
default. Other <a href="/pkg/net/http/#Transport"><code>Transport</code></a>
keep-alives</a> by default.
Other <a href="/pkg/net/http/#Transport"><code>Transport</code></a>
values with a nil <code>Dial</code> field continue to function the same
as before: no TCP keep-alives are used.
</li>
Expand All @@ -437,16 +469,17 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
<a href="/pkg/net/http/#ListenAndServe"><code>ListenAndServe</code></a>
or
<a href="/pkg/net/http/#ListenAndServeTLS"><code>ListenAndServeTLS</code></a>
are used. When a server is started otherwise, TCP keep-alives are not enabled.
are used.
When a server is started otherwise, TCP keep-alives are not enabled.
</li>

<li>
The <a href="/pkg/net/http/"><code>net/http</code></a> package now
provides an
optional <a href="/pkg/net/http/#Server"><code>Server.ConnState</code></a>
callback to hook various phases of a server connection's lifecycle
(see <a href="/pkg/net/http/#ConnState"><code>ConnState</code></a>). This
can be used to implement rate limiting or graceful shutdown.
(see <a href="/pkg/net/http/#ConnState"><code>ConnState</code></a>).
This can be used to implement rate limiting or graceful shutdown.
</li>

<li>
Expand Down

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