| <!--{ |
| "Title": "Go 1.18 Release Notes", |
| "Path": "/doc/go1.18" |
| }--> |
| |
| <!-- |
| NOTE: In this document and others in this directory, the convention is to |
| set fixed-width phrases with non-fixed-width spaces, as in |
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| |
| <style> |
| main ul li { margin: 0.5em 0; } |
| </style> |
| |
| <h2 id="introduction">DRAFT RELEASE NOTES — Introduction to Go 1.18</h2> |
| |
| <p> |
| <strong> |
| Go 1.18 is not yet released. These are work-in-progress |
| release notes. Go 1.18 is expected to be released in February 2022. |
| </strong> |
| </p> |
| |
| <h2 id="language">Changes to the language</h2> |
| |
| <p> |
| TODO: complete this section |
| </p> |
| |
| <h2 id="ports">Ports</h2> |
| |
| <p id="freebsd"> |
| Go 1.18 is the last release that is supported on FreeBSD 11.x, which has |
| already reached end-of-life. Go 1.19 will require FreeBSD 12.2+ or FreeBSD |
| 13.0+. |
| FreeBSD 13.0+ will require a kernel with the COMPAT_FREEBSD12 option set (this is the default). |
| </p> |
| |
| <h2 id="tools">Tools</h2> |
| |
| <p> |
| TODO: complete this section, or delete if not needed |
| </p> |
| |
| <h3 id="go-command">Go command</h3> |
| |
| <p><!-- golang.org/issue/43684 --> |
| <code>go</code> <code>get</code> no longer builds or installs packages in |
| module-aware mode. <code>go</code> <code>get</code> is now dedicated to |
| adjusting dependencies in <code>go.mod</code>. Effectively, the |
| <code>-d</code> flag is always enabled. To install the latest version |
| of an executable outside the context of the current module, use |
| <a href="https://golang.org/ref/mod#go-install"><code>go</code> |
| <code>install</code> <code>example.com/cmd@latest</code></a>. Any |
| <a href="https://golang.org/ref/mod#version-queries">version query</a> |
| may be used instead of <code>latest</code>. This form of <code>go</code> |
| <code>install</code> was added in Go 1.16, so projects supporting older |
| versions may need to provide install instructions for both <code>go</code> |
| <code>install</code> and <code>go</code> <code>get</code>. <code>go</code> |
| <code>get</code> now reports an error when used outside a module, since there |
| is no <code>go.mod</code> file to update. In GOPATH mode (with |
| <code>GO111MODULE=off</code>), <code>go</code> <code>get</code> still builds |
| and installs packages, as before. |
| </p> |
| |
| <p><!-- golang.org/issue/37475 --> |
| The <code>go</code> command now embeds version control information in |
| binaries including the currently checked-out revision and a flag indicating |
| whether edited or untracked files are present. Version control information |
| is embedded if the <code>go</code> command is invoked in a directory within a |
| Git or Mercurial repository, and the <code>main</code> package and its |
| containing main module are in the same repository. This information may be |
| omitted using the flag <code>-buildvcs=false</code>. |
| </p> |
| |
| <p><!-- golang.org/issue/37475 --> |
| Additionally, the <code>go</code> command embeds information about the build |
| including build and tool tags (set with <code>-tags</code>), compiler, |
| assembler, and linker flags (like <code>-gcflags</code>), whether cgo was |
| enabled, and if it was, the values of the cgo environment variables |
| (like <code>CGO_CFLAGS</code>). This information may be omitted using the |
| flag <code>-buildinfo=false</code>. Both VCS and build information may be |
| read together with module information using <code>go</code> |
| <code>version</code> <code>-m</code> <code>file</code> or |
| <code>runtime/debug.ReadBuildInfo</code> (for the currently running binary) |
| or the new <a href="#debug/buildinfo"><code>debug/buildinfo</code></a> |
| package. |
| </p> |
| |
| <p><!-- golang.org/issue/47788 --> |
| The <code>go</code> command no longer supports <code>-linkshared</code> |
| and <code>-buildmode=shared</code>. |
| (<code>shared<code> building and linking has never worked in module mode or |
| when <code>GOROOT</code> is not writable.) |
| <p> |
| |
| <p> |
| TODO: complete this section, or delete if not needed |
| </p> |
| |
| <h3 id="gofmt"><code>gofmt</code></h3> |
| |
| <p><!-- https://golang.org/issue/43566 --> |
| <code>gofmt</code> now reads and formats input files concurrently, with a |
| memory limit proportional to <code>GOMAXPROCS</code>. On a machine with |
| multiple CPUs, <code>gofmt</code> should now be significantly faster. |
| </p> |
| |
| |
| <h2 id="runtime">Runtime</h2> |
| |
| <p> |
| TODO: complete this section, or delete if not needed |
| </p> |
| |
| <h2 id="compiler">Compiler</h2> |
| |
| <p> |
| TODO: complete this section, or delete if not needed |
| </p> |
| |
| <h2 id="linker">Linker</h2> |
| |
| <p> |
| TODO: complete this section, or delete if not needed |
| </p> |
| |
| <h2 id="library">Core library</h2> |
| |
| <p> |
| TODO: complete this section |
| </p> |
| |
| <h3 id="minor_library_changes">Minor changes to the library</h3> |
| |
| <p> |
| As always, there are various minor changes and updates to the library, |
| made with the Go 1 <a href="/doc/go1compat">promise of compatibility</a> |
| in mind. |
| </p> |
| |
| <p> |
| TODO: complete this section |
| </p> |
| |
| <dl id="debug/buildinfo"><dt><a href="/pkg/debug/buildinfo">debug/buildinfo</a></dt> |
| <dd> |
| <p><!-- golang.org/issue/39301 --> |
| This new package provides access to module versions, version control |
| information, and build flags embedded in executable files built by |
| the <code>go</code> command. The same information is also available via |
| <a href="/pkg/runtime/debug#ReadBuildInfo"><code>runtime/debug.ReadBuildInfo</code></a> |
| for the currently running binary and via <code>go</code> |
| <code>version</code> <code>-m</code> on the command line. |
| </p> |
| </dd> |
| </dl> |
| |
| <dl id="image/draw"><dt><a href="/pkg/image/draw/">image/draw</a></dt> |
| <dd> |
| <p><!-- CL 340049 --> |
| The <code>Draw</code> and <code>DrawMask</code> fallback implementations |
| (used when the arguments are not the most common image types) are now |
| faster when those arguments implement the optional |
| <a href="/pkg/image/draw/#RGBA64Image"><code>draw.RGBA64Image</code></a> |
| and <a href="/pkg/image/#RGBA64Image"><code>image.RGBA64Image</code></a> |
| interfaces that were added in Go 1.17. |
| </p> |
| </dd> |
| </dl><!-- image/draw --> |
| |
| <dl id="reflect"><dt><a href="/pkg/reflect/">reflect</a></dt> |
| <dd> |
| <p><!-- CL 356049, 320929 --> |
| The new |
| <a href="/pkg/reflect/#Value.SetIterKey"><code>Value.SetIterKey</code></a> |
| and <a href="/pkg/reflect/#Value.SetIterValue"><code>Value.SetIterValue</code></a> |
| methods set a Value using a map iterator as the source. They are equivalent to |
| <code>Value.Set(iter.Key())</code> and <code>Value.Set(iter.Value())</code> but |
| do fewer allocations. |
| </p> |
| </dd> |
| <dd> |
| <p><!-- CL 350691 --> |
| The new |
| <a href="/pkg/reflect/#Value.UnsafePointer"><code>Value.UnsafePointer</code></a> |
| method returns the Value's value as an <a href="/pkg/unsafe/#Pointer"><code>unsafe.Pointer</code></a>. |
| This allows callers to migrate from <a href="/pkg/reflect/#Value.UnsafeAddr"><code>Value.UnsafeAddr</code></a> |
| and <a href="/pkg/reflect/#Value.Pointer"><code>Value.Pointer</code></a> |
| to eliminate the need to perform uintptr to unsafe.Pointer conversions at the callsite (as unsafe.Pointer rules require). |
| </p> |
| </dd> |
| </dl><!-- reflect --> |
| |
| <dl id="syscall"><dt><a href="/pkg/syscall/">syscall</a></dt> |
| <dd> |
| <p><!-- CL 336550 --> |
| The new function <a href="/pkg/syscall/?GOOS=windows#SyscallN"><code>SyscallN</code></a> |
| has been introduced for Windows, allowing for calls with arbitrary number |
| of arguments. As a result, |
| <a href="/pkg/syscall/?GOOS=windows#Syscall"><code>Syscall</code></a>, |
| <a href="/pkg/syscall/?GOOS=windows#Syscall6"><code>Syscall6</code></a>, |
| <a href="/pkg/syscall/?GOOS=windows#Syscall9"><code>Syscall9</code></a>, |
| <a href="/pkg/syscall/?GOOS=windows#Syscall12"><code>Syscall12</code></a>, |
| <a href="/pkg/syscall/?GOOS=windows#Syscall15"><code>Syscall15</code></a>, and |
| <a href="/pkg/syscall/?GOOS=windows#Syscall18"><code>Syscall18</code></a> are |
| deprecated in favor of <a href="/pkg/syscall/?GOOS=windows#SyscallN"><code>SyscallN</code></a>. |
| </p> |
| </dd> |
| </dl><!-- syscall --> |