diff options
author | Michael Anthony Knyszek <mknyszek@google.com> | 2023-01-30 17:51:32 +0000 |
---|---|---|
committer | Gopher Robot <gobot@golang.org> | 2023-01-30 21:10:03 +0000 |
commit | 0a27a458960ffb0adff2f9491eca68c72b79967c (patch) | |
tree | 47f10cc6269a8fa702b76a9eb2590f1d6ba9be25 /doc | |
parent | 2ab0e04681332c88e1bfb5fe5a72d35c1c5aae8a (diff) | |
download | go-git-0a27a458960ffb0adff2f9491eca68c72b79967c.tar.gz |
doc: move Go 1.20 release notes to x/website
Now that the development of the Go 1.20 release is almost done, its
release notes are moved to their eventual long-term home in x/website
in CL 464075. Delete the initial development copy here.
For golang/go#54202.
Change-Id: Ia402d1abd4539fbce415e2a7dffd6709186f08a7
Reviewed-on: https://go-review.googlesource.com/c/go/+/464055
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Diffstat (limited to 'doc')
-rw-r--r-- | doc/go1.20.html | 1246 |
1 files changed, 0 insertions, 1246 deletions
diff --git a/doc/go1.20.html b/doc/go1.20.html deleted file mode 100644 index 1fef45204e..0000000000 --- a/doc/go1.20.html +++ /dev/null @@ -1,1246 +0,0 @@ -<!--{ - "Title": "Go 1.20 Release Notes", - "Path": "/doc/go1.20" -}--> - -<!-- -NOTE: In this document and others in this directory, the convention is to -set fixed-width phrases with non-fixed-width spaces, as in -<code>hello</code> <code>world</code>. -Do not send CLs removing the interior tags from such phrases. ---> - -<style> - main ul li { margin: 0.5em 0; } -</style> - -<h2 id="introduction">DRAFT RELEASE NOTES — Introduction to Go 1.20</h2> - -<p> - <strong> - Go 1.20 is not yet released. These are work-in-progress - release notes. Go 1.20 is expected to be released in February 2023. - </strong> -</p> - -<h2 id="language">Changes to the language</h2> - -<p> - Go 1.20 includes four changes to the language. -</p> - -<p><!-- https://go.dev/issue/46505 --> - Go 1.17 added <a href="/ref/spec#Conversions_from_slice_to_array_or_array_pointer">conversions from slice to an array pointer</a>. - Go 1.20 extends this to allow conversions from a slice to an array: - given a slice <code>x</code>, <code>[4]byte(x)</code> can now be written - instead of <code>*(*[4]byte)(x)</code>. -</p> - -<p><!-- https://go.dev/issue/53003 --> - The <a href="/ref/spec/#Package_unsafe"><code>unsafe</code> package</a> defines - three new functions <code>SliceData</code>, <code>String</code>, and <code>StringData</code>. - Along with Go 1.17's <code>Slice</code>, these functions now provide the complete ability to - construct and deconstruct slice and string values, without depending on their exact representation. -</p> - -<p><!-- https://go.dev/issue/8606 --> - The specification now defines that struct values are compared one field at a time, - considering fields in the order they appear in the struct type definition, - and stopping at the first mismatch. - The specification could previously have been read as if - all fields needed to be compared beyond the first mismatch. - Similarly, the specification now defines that array values are compared - one element at a time, in increasing index order. - In both cases, the difference affects whether certain comparisons must panic. - Existing programs are unchanged: the new spec wording describes - what the implementations have always done. -</p> - -<p><!-- https://go.dev/issue/56548 --> - <a href="/ref/spec#Comparison_operators">Comparable types</a> (such as ordinary interfaces) - may now satisfy <code>comparable</code> constraints, even if the type arguments - are not strictly comparable (comparison may panic at runtime). - This makes it possible to instantiate a type parameter constrained by <code>comparable</code> - (e.g., a type parameter for a user-defined generic map key) with a non-strictly comparable type argument - such as an interface type, or a composite type containing an interface type. -</p> - -<h2 id="ports">Ports</h2> - -<h3 id="windows">Windows</h3> - -<p><!-- https://go.dev/issue/57003, https://go.dev/issue/57004 --> - Go 1.20 is the last release that will run on any release of Windows 7, 8, Server 2008 and Server 2012. - Go 1.21 will require at least Windows 10 or Server 2016. -</p> - -<h3 id="darwin">Darwin and iOS</h3> - -<p><!-- https://go.dev/issue/23011 --> - Go 1.20 is the last release that will run on macOS 10.13 High Sierra or 10.14 Mojave. - Go 1.21 will require macOS 10.15 Catalina or later. -</p> - -<h3 id="freebsd-riscv">FreeBSD/RISC-V</h3> - -<p><!-- https://go.dev/issue/53466 --> - Go 1.20 adds experimental support for FreeBSD on RISC-V (<code>GOOS=freebsd</code>, <code>GOARCH=riscv64</code>). -</p> - -<h2 id="tools">Tools</h2> - -<h3 id="go-command">Go command</h3> - -<p><!-- CL 432535, https://go.dev/issue/47257 --> - The directory <code>$GOROOT/pkg</code> no longer stores - pre-compiled package archives for the standard library: - <code>go</code> <code>install</code> no longer writes them, - the <code>go</code> build no longer checks for them, - and the Go distribution no longer ships them. - Instead, packages in the standard library are built as needed - and cached in the build cache, just like packages outside <code>GOROOT</code>. - This change reduces the size of the Go distribution and also - avoids C toolchain skew for packages that use cgo. -</p> - -<p><!-- CL 448357: cmd/go: print test2json start events --> - The implementation of <code>go</code> <code>test</code> <code>-json</code> - has been improved to make it more robust. - Programs that run <code>go</code> <code>test</code> <code>-json</code> - do not need any updates. - Programs that invoke <code>go</code> <code>tool</code> <code>test2json</code> - directly should now run the test binary with <code>-v=test2json</code> - (for example, <code>go</code> <code>test</code> <code>-v=test2json</code> - or <code>./pkg.test</code> <code>-test.v=test2json</code>) - instead of plain <code>-v</code>. -</p> - -<p><!-- CL 448357: cmd/go: print test2json start events --> - A related change to <code>go</code> <code>test</code> <code>-json</code> - is the addition of an event with <code>Action</code> set to <code>start</code> - at the beginning of each test program's execution. - When running multiple tests using the <code>go</code> command, - these start events are guaranteed to be emitted in the same order as - the packages named on the command line. -</p> - -<p><!-- https://go.dev/issue/45454, CL 421434 --> - The <code>go</code> command now defines - architecture feature build tags, such as <code>amd64.v2</code>, - to allow selecting a package implementation file based on the presence - or absence of a particular architecture feature. - See <a href="/cmd/go#hdr-Build_constraints"><code>go</code> <code>help</code> <code>buildconstraint</code></a> for details. -</p> - -<p><!-- https://go.dev/issue/50332 --> - The <code>go</code> subcommands now accept - <code>-C</code> <code><dir></code> to change directory to <dir> - before performing the command, which may be useful for scripts that need to - execute commands in multiple different modules. -</p> - -<p><!-- https://go.dev/issue/41696, CL 416094 --> - The <code>go</code> <code>build</code> and <code>go</code> <code>test</code> - commands no longer accept the <code>-i</code> flag, - which has been <a href="https://go.dev/issue/41696">deprecated since Go 1.16</a>. -</p> - -<p><!-- https://go.dev/issue/38687, CL 421440 --> - The <code>go</code> <code>generate</code> command now accepts - <code>-skip</code> <code><pattern></code> to skip <code>//go:generate</code> directives - matching <code><pattern></code>. -</p> - -<p><!-- https://go.dev/issue/41583 --> - The <code>go</code> <code>test</code> command now accepts - <code>-skip</code> <code><pattern></code> to skip tests, subtests, or examples - matching <code><pattern></code>. -</p> - -<p><!-- https://go.dev/issue/37015 --> - When the main module is located within <code>GOPATH/src</code>, - <code>go</code> <code>install</code> no longer installs libraries for - non-<code>main</code> packages to <code>GOPATH/pkg</code>, - and <code>go</code> <code>list</code> no longer reports a <code>Target</code> - field for such packages. (In module mode, compiled packages are stored in the - <a href="https://pkg.go.dev/cmd/go#hdr-Build_and_test_caching">build cache</a> - only, but <a href="https://go.dev/issue/37015">a bug</a> had caused - the <code>GOPATH</code> install targets to unexpectedly remain in effect.) -</p> - -<p><!-- https://go.dev/issue/55022 --> - The <code>go</code> <code>build</code>, <code>go</code> <code>install</code>, - and other build-related commands now support a <code>-pgo</code> flag that enables - profile-guided optimization, which is described in more detail in the - <a href="#compiler">Compiler</a> section below. - The <code>-pgo</code> flag specifies the file path of the profile. - Specifying <code>-pgo=auto</code> causes the <code>go</code> command to search - for a file named <code>default.pgo</code> in the main package's directory and - use it if present. - This mode currently requires a single main package to be specified on the - command line, but we plan to lift this restriction in a future release. - Specifying <code>-pgo=off</code> turns off profile-guided optimization. -</p> - -<p><!-- https://go.dev/issue/51430 --> - The <code>go</code> <code>build</code>, <code>go</code> <code>install</code>, - and other build-related commands now support a <code>-cover</code> - flag that builds the specified target with code coverage instrumentation. - This is described in more detail in the - <a href="#cover">Cover</a> section below. -</p> - -<h4 id="go-version"><code>go</code> <code>version</code></h4> - -<p><!-- https://go.dev/issue/48187 --> - The <code>go</code> <code>version</code> <code>-m</code> command - now supports reading more types of Go binaries, most notably, Windows DLLs - built with <code>go</code> <code>build</code> <code>-buildmode=c-shared</code> - and Linux binaries without execute permission. -</p> - -<h3 id="cgo">Cgo</h3> - -<p><!-- CL 450739 --> - The <code>go</code> command now disables <code>cgo</code> by default - on systems without a C toolchain. - More specifically, when the <code>CGO_ENABLED</code> environment variable is unset, - the <code>CC</code> environment variable is unset, - and the default C compiler (typically <code>clang</code> or <code>gcc</code>) - is not found in the path, - <code>CGO_ENABLED</code> defaults to <code>0</code>. - As always, you can override the default by setting <code>CGO_ENABLED</code> explicitly. -</p> - -<p> - The most important effect of the default change is that when Go is installed - on a system without a C compiler, it will now use pure Go builds for packages - in the standard library that use cgo, instead of using pre-distributed package archives - (which have been removed, as <a href="#go-command">noted above</a>) - or attempting to use cgo and failing. - This makes Go work better in some minimal container environments - as well as on macOS, where pre-distributed package archives have - not been used for cgo-based packages since Go 1.16. -</p> - -<p> - The packages in the standard library that use cgo are <a href="/pkg/net/"><code>net</code></a>, - <a href="/pkg/os/user/"><code>os/user</code></a>, and - <a href="/pkg/plugin/"><code>plugin</code></a>. - On macOS, the <code>net</code> and <code>os/user</code> packages have been rewritten not to use cgo: - the same code is now used for cgo and non-cgo builds as well as cross-compiled builds. - On Windows, the <code>net</code> and <code>os/user</code> packages have never used cgo. - On other systems, builds with cgo disabled will use a pure Go version of these packages. -</p> - -<p> - On macOS, the race detector has been rewritten not to use cgo: - race-detector-enabled programs can be built and run without Xcode. - On Linux and other Unix systems, and on Windows, a host C toolchain - is required to use the race detector. -</p> - -<h3 id="cover">Cover</h3> - -<p><!-- CL 436236, CL 401236, CL 438503 --> - Go 1.20 supports collecting code coverage profiles for programs - (applications and integration tests), as opposed to just unit tests. -</p> - -<p> - To collect coverage data for a program, build it with <code>go</code> - <code>build</code>'s <code>-cover</code> flag, then run the resulting - binary with the environment variable <code>GOCOVERDIR</code> set - to an output directory for coverage profiles. - See the - <a href="https://go.dev/testing/coverage">'coverage for integration tests' landing page</a> for more on how to get started. - For details on the design and implementation, see the - <a href="https://golang.org/issue/51430">proposal</a>. -</p> - -<h3 id="vet">Vet</h3> - -<h4 id="vet-loopclosure">Improved detection of loop variable capture by nested functions</h4> - -<p><!-- CL 447256, https://go.dev/issue/55972: extend the loopclosure analysis to parallel subtests --> - The <code>vet</code> tool now reports references to loop variables following - a call to <a href="/pkg/testing/#T.Parallel"><code>T.Parallel()</code></a> - within subtest function bodies. Such references may observe the value of the - variable from a different iteration (typically causing test cases to be - skipped) or an invalid state due to unsynchronized concurrent access. -</p> - -<p><!-- CL 452615 --> - The tool also detects reference mistakes in more places. Previously it would - only consider the last statement of the loop body, but now it recursively - inspects the last statements within if, switch, and select statements. -</p> - -<h4 id="vet-timeformat">New diagnostic for incorrect time formats</h4> - -<p><!-- CL 354010, https://go.dev/issue/48801: check for time formats with 2006-02-01 --> - The vet tool now reports use of the time format 2006-02-01 (yyyy-dd-mm) - with <a href="/pkg/time/#Time.Format"><code>Time.Format</code></a> and - <a href="/pkg/time/#Parse"><code>time.Parse</code></a>. - This format does not appear in common date standards, but is frequently - used by mistake when attempting to use the ISO 8601 date format - (yyyy-mm-dd). -</p> - -<h2 id="runtime">Runtime</h2> - -<p><!-- CL 422634 --> - Some of the garbage collector's internal data structures were reorganized to - be both more space and CPU efficient. - This change reduces memory overheads and improves overall CPU performance by - up to 2%. -</p> - -<p><!-- CL 417558, https://go.dev/issue/53892 --> - The garbage collector behaves less erratically with respect to goroutine - assists in some circumstances. -</p> - -<p><!-- https://go.dev/issue/51430 --> - Go 1.20 adds a new <code>runtime/coverage</code> package - containing APIs for writing coverage profile data at - runtime from long-running and/or server programs that - do not terminate via <code>os.Exit()</code>. -</p> - -<h2 id="compiler">Compiler</h2> - -<p><!-- https://go.dev/issue/55022 --> - Go 1.20 adds preview support for profile-guided optimization (PGO). - PGO enables the toolchain to perform application- and workload-specific - optimizations based on run-time profile information. - Currently, the compiler supports pprof CPU profiles, which can be collected - through usual means, such as the <code>runtime/pprof</code> or - <code>net/http/pprof</code> packages. - To enable PGO, pass the path of a pprof profile file via the - <code>-pgo</code> flag to <code>go</code> <code>build</code>, - as mentioned <a href="#go-command">above</a>. - Go 1.20 uses PGO to more aggressively inline functions at hot call sites. - Benchmarks for a representative set of Go programs show enabling - profile-guided inlining optimization improves performance about 3–4%. - We plan to add more profile-guided optimizations in future releases. - Note that profile-guided optimization is a preview, so please use it - with appropriate caution. -</p> - -<p> - The Go 1.20 compiler upgraded its front-end to use a new way of handling the - compiler's internal data, which fixes several generic-types bugs and enables - local types in generic functions and methods. -</p> - -<p><!-- https://go.dev/issue/56103, CL 445598 --> - The compiler now <a href="https://go.dev/issue/56103">disallows anonymous interface cycles</a>. -</p> - -<p><!-- https://go.dev/issue/49569 --> - Go 1.18 and 1.19 saw regressions in build speed, largely due to the addition - of support for generics and follow-on work. Go 1.20 improves build speeds by - up to 10%, bringing it back in line with Go 1.17. - Relative to Go 1.19, generated code performance is also generally slightly improved. -</p> - -<h2 id="linker">Linker</h2> - -<p><!-- https://go.dev/issue/54197, CL 420774 --> - On Linux, the linker now selects the dynamic interpreter for <code>glibc</code> - or <code>musl</code> at link time. -</p> - -<p><!-- https://go.dev/issue/35006 --> - On Windows, the Go linker now supports modern LLVM-based C toolchains. -</p> - -<p><!-- https://go.dev/issue/37762, CL 317917 --> - Go 1.20 uses <code>go:</code> and <code>type:</code> prefixes for compiler-generated - symbols rather than <code>go.</code> and <code>type.</code>. - This avoids confusion for user packages whose name starts with <code>go.</code>. - The <a href="/pkg/debug/gosym"><code>debug/gosym</code></a> package understands - this new naming convention for binaries built with Go 1.20 and newer. -</p> - -<h2 id="bootstrap">Bootstrap</h2> - -<p><!-- https://go.dev/issue/44505 --> - When building a Go release from source and <code>GOROOT_BOOTSTRAP</code> is not set, - previous versions of Go looked for a Go 1.4 or later bootstrap toolchain in the directory - <code>$HOME/go1.4</code> (<code>%HOMEDRIVE%%HOMEPATH%\go1.4</code> on Windows). - Go 1.18 and Go 1.19 looked first for <code>$HOME/go1.17</code> or <code>$HOME/sdk/go1.17</code> - before falling back to <code>$HOME/go1.4</code>, - in anticipation of requiring Go 1.17 for use when bootstrapping Go 1.20. - Go 1.20 does require a Go 1.17 release for bootstrapping, but we realized that we should - adopt the latest point release of the bootstrap toolchain, so it requires Go 1.17.13. - Go 1.20 looks for <code>$HOME/go1.17.13</code> or <code>$HOME/sdk/go1.17.13</code> - before falling back to <code>$HOME/go1.4</code> - (to support systems that hard-coded the path $HOME/go1.4 but have installed - a newer Go toolchain there). - In the future, we plan to move the bootstrap toolchain forward approximately once a year, - and in particular we expect that Go 1.22 will require the final point release of Go 1.20 for bootstrap. -</p> - -<h2 id="library">Core library</h2> - -<h3 id="crypto/ecdh">New crypto/ecdh package</h3> - -<p><!-- https://go.dev/issue/52221, CL 398914, CL 450335, https://go.dev/issue/56052 --> - Go 1.20 adds a new <a href="/pkg/crypto/ecdh/"><code>crypto/ecdh</code></a> package - to provide explicit support for Elliptic Curve Diffie-Hellman key exchanges - over NIST curves and Curve25519. -</p> -<p> - Programs should use <code>crypto/ecdh</code> instead of the lower-level functionality in - <a href="/pkg/crypto/elliptic/"><code>crypto/elliptic</code></a> for ECDH, and - third-party modules for more advanced use cases. -</p> - -<h3 id="errors">Wrapping multiple errors</h3> - -<p><!-- CL 432898 --> - Go 1.20 expands support for error wrapping to permit an error to - wrap multiple other errors. -</p> -<p> - An error <code>e</code> can wrap more than one error by providing - an <code>Unwrap</code> method that returns a <code>[]error</code>. -</p> -<p> - The <a href="/pkg/errors/#Is"><code>errors.Is</code></a> and - <a href="/pkg/errors/#As"><code>errors.As</code></a> functions - have been updated to inspect multiply wrapped errors. -</p> -<p> - The <a href="/pkg/fmt/#Errorf"><code>fmt.Errorf</code></a> function - now supports multiple occurrences of the <code>%w</code> format verb, - which will cause it to return an error that wraps all of those error operands. -</p> -<p> - The new function <a href="/pkg/errors/#Join"><code>errors.Join</code></a> - returns an error wrapping a list of errors. -</p> - -<h3 id="http_responsecontroller">HTTP ResponseController</h3> - -<p><!-- CL 436890, https://go.dev/issue/54136 --> - The new - <a href="/pkg/net/http/#ResponseController"><code>"net/http".ResponseController</code></a> - type provides access to extended per-request functionality not handled by the - <a href="/pkg/net/http/#ResponseWriter"><code>"net/http".ResponseWriter</code></a> interface. -</p> - -<p> - Previously, we have added new per-request functionality by defining optional - interfaces which a <code>ResponseWriter</code> can implement, such as - <a href="/pkg/net/http/#Flusher"><code>Flusher</code></a>. These interfaces - are not discoverable and clumsy to use. -</p> - -<p> - The <code>ResponseController</code> type provides a clearer, more discoverable way - to add per-handler controls. Two such controls also added in Go 1.20 are - <code>SetReadDeadline</code> and <code>SetWriteDeadline</code>, which allow setting - per-request read and write deadlines. For example: -</p> - -<pre> -func RequestHandler(w ResponseWriter, r *Request) { - rc := http.NewResponseController(w) - rc.SetWriteDeadline(time.Time{}) // disable Server.WriteTimeout when sending a large response - io.Copy(w, bigData) -} -</pre> - -<h3 id="reverseproxy_rewrite">New ReverseProxy Rewrite hook</h3> - -<p><!-- https://go.dev/issue/53002, CL 407214 --> - The <a href="/pkg/net/http/httputil/#ReverseProxy"><code>httputil.ReverseProxy</code></a> - forwarding proxy includes a new - <a href="/pkg/net/http/httputil/#ReverseProxy.Rewrite"><code>Rewrite</code></a> - hook function, superseding the - previous <code>Director</code> hook. -</p> - -<p> - The <code>Rewrite</code> hook accepts a - <a href="/pkg/net/http/httputil/#ProxyRequest"><code>ProxyRequest</code></a> parameter, - which includes both the inbound request received by the proxy and the outbound - request that it will send. - Unlike <code>Director</code> hooks, which only operate on the outbound request, - this permits <code>Rewrite</code> hooks to avoid certain scenarios where - a malicious inbound request may cause headers added by the hook - to be removed before forwarding. - See <a href="https://go.dev/issue/50580">issue #50580</a>. -</p> - -<p> - The <a href="/pkg/net/http/httputil/#ProxyRequest.SetURL"><code>ProxyRequest.SetURL</code></a> - method routes the outbound request to a provided destination - and supersedes the <code>NewSingleHostReverseProxy</code> function. - Unlike <code>NewSingleHostReverseProxy</code>, <code>SetURL</code> - also sets the <code>Host</code> header of the outbound request. -</p> - -<p><!-- https://go.dev/issue/50465, CL 407414 --> - The - <a href="/pkg/net/http/httputil/#ProxyRequest.SetXForwarded"><code>ProxyRequest.SetXForwarded</code></a> - method sets the <code>X-Forwarded-For</code>, <code>X-Forwarded-Host</code>, - and <code>X-Forwarded-Proto</code> headers of the outbound request. - When using a <code>Rewrite</code>, these headers are not added by default. -</p> - -<p> - An example of a <code>Rewrite</code> hook using these features is: -</p> - -<pre> -proxyHandler := &httputil.ReverseProxy{ - Rewrite: func(r *httputil.ProxyRequest) { - r.SetURL(outboundURL) // Forward request to outboundURL. - r.SetXForwarded() // Set X-Forwarded-* headers. - r.Out.Header.Set("X-Additional-Header", "header set by the proxy") - }, -} -</pre> - -<p><!-- CL 407375 --> - <a href="/pkg/net/http/httputil/#ReverseProxy"><code>ReverseProxy</code></a> no longer adds a <code>User-Agent</code> header - to forwarded requests when the incoming request does not have one. -</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. - There are also various performance improvements, not enumerated here. -</p> - -<dl id="archive/tar"><dt><a href="/pkg/archive/tar/">archive/tar</a></dt> - <dd> - <p><!-- https://go.dev/issue/55356, CL 449937 --> - When the <code>GODEBUG=tarinsecurepath=0</code> environment variable is set, - <a href="/pkg/archive/tar/#Reader.Next"><code>Reader.Next</code></a> method - will now return the error <a href="/pkg/archive/tar/#ErrInsecurePath"><code>ErrInsecurePath</code></a> - for an entry with a file name that is an absolute path, - refers to a location outside the current directory, contains invalid - characters, or (on Windows) is a reserved name such as <code>NUL</code>. - A future version of Go may disable insecure paths by default. - </p> - </dd> -</dl><!-- archive/tar --> - -<dl id="archive/zip"><dt><a href="/pkg/archive/zip/">archive/zip</a></dt> - <dd> - <p><!-- https://go.dev/issue/55356 --> - When the <code>GODEBUG=zipinsecurepath=0</code> environment variable is set, - <a href="/pkg/archive/zip/#NewReader"><code>NewReader</code></a> will now return the error - <a href="/pkg/archive/zip/#ErrInsecurePath"><code>ErrInsecurePath</code></a> - when opening an archive which contains any file name that is an absolute path, - refers to a location outside the current directory, contains invalid - characters, or (on Windows) is a reserved names such as <code>NUL</code>. - A future version of Go may disable insecure paths by default. - </p> - <p><!-- CL 449955 --> - Reading from a directory file that contains file data will now return an error. - The zip specification does not permit directory files to contain file data, - so this change only affects reading from invalid archives. - </p> - </dd> -</dl><!-- archive/zip --> - -<dl id="bytes"><dt><a href="/pkg/bytes/">bytes</a></dt> - <dd> - <p><!-- CL 407176 --> - The new - <a href="/pkg/bytes/#CutPrefix"><code>CutPrefix</code></a> and - <a href="/pkg/bytes/#CutSuffix"><code>CutSuffix</code></a> functions - are like <a href="/pkg/bytes/#TrimPrefix"><code>TrimPrefix</code></a> - and <a href="/pkg/bytes/#TrimSuffix"><code>TrimSuffix</code></a> - but also report whether the string was trimmed. - </p> - - <p><!-- CL 359675, https://go.dev/issue/45038 --> - The new <a href="/pkg/bytes/#Clone"><code>Clone</code></a> function - allocates a copy of a byte slice. - </p> - </dd> -</dl><!-- bytes --> - -<dl id="context"><dt><a href="/pkg/context/">context</a></dt> - <dd> - <p><!-- https://go.dev/issue/51365, CL 375977 --> - The new <a href="/pkg/context/#WithCancelCause"><code>WithCancelCause</code></a> function - provides a way to cancel a context with a given error. - That error can be retrieved by calling the new <a href="/pkg/context/#Cause"><code>Cause</code></a> function. - </p> - </dd> -</dl><!-- context --> - -<dl id="crypto/ecdsa"><dt><a href="/pkg/crypto/ecdsa/">crypto/ecdsa</a></dt> - <dd> - <p><!-- CL 353849 --> - When using supported curves, all operations are now implemented in constant time. - This led to an increase in CPU time between 5% and 30%, mostly affecting P-384 and P-521. - </p> - - <p><!-- https://go.dev/issue/56088, CL 450816 --> - The new <a href="/pkg/crypto/ecdsa/#PrivateKey.ECDH"><code>PrivateKey.ECDH</code></a> method - converts an <code>ecdsa.PrivateKey</code> to an <code>ecdh.PrivateKey</code>. - </p> - </dd> -</dl><!-- crypto/ecdsa --> - -<dl id="crypto/ed25519"><dt><a href="/pkg/crypto/ed25519/">crypto/ed25519</a></dt> - <dd> - <p><!-- CL 373076, CL 404274, https://go.dev/issue/31804 --> - The <a href="/pkg/crypto/ed25519/#PrivateKey.Sign"><code>PrivateKey.Sign</code></a> method - and the - <a href="/pkg/crypto/ed25519/#VerifyWithOptions"><code>VerifyWithOptions</code></a> function - now support signing pre-hashed messages with Ed25519ph, - indicated by an - <a href="/pkg/crypto/ed25519/#Options.HashFunc"><code>Options.HashFunc</code></a> - that returns - <a href="/pkg/crypto/#SHA512"><code>crypto.SHA512</code></a>. - They also now support Ed25519ctx and Ed25519ph with context, - indicated by setting the new - <a href="/pkg/crypto/ed25519/#Options.Context"><code>Options.Context</code></a> - field. - </p> - </dd> -</dl><!-- crypto/ed25519 --> - -<dl id="crypto/rsa"><dt><a href="/pkg/crypto/rsa/">crypto/rsa</a></dt> - <dd> - <p><!-- CL 418874, https://go.dev/issue/19974 --> - The new field <a href="/pkg/crypto/rsa/#OAEPOptions.MGFHash"><code>OAEPOptions.MGFHash</code></a> - allows configuring the MGF1 hash separately for OAEP decryption. - </p> - - <p><!-- https://go.dev/issue/20654 --> - crypto/rsa now uses a new, safer, constant-time backend. This causes a CPU - runtime increase for decryption operations between approximately 15% - (RSA-2048 on amd64) and 45% (RSA-4096 on arm64), and more on 32-bit architectures. - Encryption operations are approximately 20x slower than before (but still 5-10x faster than decryption). - Performance is expected to improve in future releases. - Programs must not modify or manually generate the fields of - <a href="/pkg/crypto/rsa/#PrecomputedValues"><code>PrecomputedValues</code></a>. - </p> - </dd> -</dl><!-- crypto/rsa --> - -<dl id="crypto/subtle"><dt><a href="/pkg/crypto/subtle/">crypto/subtle</a></dt> - <dd> - <p><!-- https://go.dev/issue/53021, CL 421435 --> - The new function <a href="/pkg/crypto/subtle/#XORBytes"><code>XORBytes</code></a> - XORs two byte slices together. - </p> - </dd> -</dl><!-- crypto/subtle --> - -<dl id="crypto/tls"><dt><a href="/pkg/crypto/tls/">crypto/tls</a></dt> - <dd> - <p><!-- CL 426455, CL 427155, CL 426454, https://go.dev/issue/46035 --> - Parsed certificates are now shared across all clients actively using that certificate. - The memory savings can be significant in programs that make many concurrent connections to a - server or collection of servers sharing any part of their certificate chains. - </p> - - <p><!-- https://go.dev/issue/48152, CL 449336 --> - For a handshake failure due to a certificate verification failure, - the TLS client and server now return an error of the new type - <a href="/pkg/crypto/tls/#CertificateVerificationError"><code>CertificateVerificationError</code></a>, - which includes the presented certificates. - </p> - </dd> -</dl><!-- crypto/tls --> - -<dl id="crypto/x509"><dt><a href="/pkg/crypto/x509/">crypto/x509</a></dt> - <dd> - <p><!-- CL 450816, CL 450815 --> - <a href="/pkg/crypto/x509/#ParsePKCS8PrivateKey"><code>ParsePKCS8PrivateKey</code></a> - and - <a href="/pkg/crypto/x509/#MarshalPKCS8PrivateKey"><code>MarshalPKCS8PrivateKey</code></a> - now support keys of type <a href="/pkg/crypto/ecdh.PrivateKey"><code>*crypto/ecdh.PrivateKey</code></a>. - <a href="/pkg/crypto/x509/#ParsePKIXPublicKey"><code>ParsePKIXPublicKey</code></a> - and - <a href="/pkg/crypto/x509/#MarshalPKIXPublicKey"><code>MarshalPKIXPublicKey</code></a> - now support keys of type <a href="/pkg/crypto/ecdh.PublicKey"><code>*crypto/ecdh.PublicKey</code></a>. - Parsing NIST curve keys still returns values of type - <code>*ecdsa.PublicKey</code> and <code>*ecdsa.PrivateKey</code>. - Use their new <code>ECDH</code> methods to convert to the <code>crypto/ecdh</code> types. - </p> - <p><!-- CL 449235 --> - The new <a href="/pkg/crypto/x509/#SetFallbackRoots"><code>SetFallbackRoots</code></a> - function allows a program to define a set of fallback root certificates in case an - operating system verifier or standard platform root bundle is unavailable at runtime. - It will most commonly be used with a new package, <a href="/pkg/golang.org/x/crypto/x509roots/fallback">golang.org/x/crypto/x509roots/fallback</a>, - which will provide an up to date root bundle. - </p> - </dd> -</dl><!-- crypto/x509 --> - -<dl id="debug/elf"><dt><a href="/pkg/debug/elf/">debug/elf</a></dt> - <dd> - <p><!-- CL 429601 --> - Attempts to read from a <code>SHT_NOBITS</code> section using - <a href="/pkg/debug/elf/#Section.Data"><code>Section.Data</code></a> - or the reader returned by <a href="/pkg/debug/elf/#Section.Open"><code>Section.Open</code></a> - now return an error. - </p> - <p><!-- CL 420982 --> - Additional <a href="/pkg/debug/elf/#R_LARCH"><code>R_LARCH_*</code></a> constants are defined for use with LoongArch systems. - </p> - <p><!-- CL 420982, CL 435415, CL 425555 --> - Additional <a href="/pkg/debug/elf/#R_PPC64"><code>R_PPC64_*</code></a> constants are defined for use with PPC64 ELFv2 relocations. - </p> - <p><!-- CL 411915 --> - The constant value for <a href="/pkg/debug/elf/#R_PPC64_SECTOFF_LO_DS"><code>R_PPC64_SECTOFF_LO_DS</code></a> is corrected, from 61 to 62. - </p> - </dd> -</dl><!-- debug/elf --> - -<dl id="debug/gosym"><dt><a href="/pkg/debug/gosym/">debug/gosym</a></dt> - <dd> - <p><!-- https://go.dev/issue/37762, CL 317917 --> - Due to a change of <a href="#linker">Go's symbol naming conventions</a>, tools that - process Go binaries should use Go 1.20's <code>debug/gosym</code> package to - transparently handle both old and new binaries. - </p> - </dd> -</dl><!-- debug/gosym --> - -<dl id="debug/pe"><dt><a href="/pkg/debug/pe/">debug/pe</a></dt> - <dd> - <p><!-- CL 421357 --> - Additional <a href="/pkg/debug/pe/#IMAGE_FILE_MACHINE_RISCV128"><code>IMAGE_FILE_MACHINE_RISCV*</code></a> constants are defined for use with RISC-V systems. - </p> - </dd> -</dl><!-- debug/pe --> - -<dl id="encoding/binary"><dt><a href="/pkg/encoding/binary/">encoding/binary</a></dt> - <dd> - <p><!-- CL 420274 --> - The <a href="/pkg/encoding/binary/#ReadVarint"><code>ReadVarint</code></a> and - <a href="/pkg/encoding/binary/#ReadUvarint"><code>ReadUvarint</code></a> - functions will now return <code>io.ErrUnexpectedEOF</code> after reading a partial value, - rather than <code>io.EOF</code>. - </p> - </dd> -</dl><!-- encoding/binary --> - -<dl id="encoding/xml"><dt><a href="/pkg/encoding/xml/">encoding/xml</a></dt> - <dd> - <p><!-- https://go.dev/issue/53346, CL 424777 --> - The new <a href="/pkg/encoding/xml/#Encoder.Close"><code>Encoder.Close</code></a> method - can be used to check for unclosed elements when finished encoding. - </p> - - <p><!-- CL 103875, CL 105636 --> - The decoder now rejects element and attribute names with more than one colon, - such as <code><a:b:c></code>, - as well as namespaces that resolve to an empty string, such as <code>xmlns:a=""</code>. - </p> - - <p><!-- CL 107255 --> - The decoder now rejects elements that use different namespace prefixes in the opening and closing tag, - even if those prefixes both denote the same namespace. - </p> - </dd> -</dl><!-- encoding/xml --> - -<dl id="errors"><dt><a href="/pkg/errors/">errors</a></dt> - <dd> - <p><!-- https://go.dev/issue/53435 --> - The new <a href="/pkg/errors/#Join"><code>Join</code></a> function returns an error wrapping a list of errors. - </p> - </dd> -</dl><!-- errors --> - -<dl id="fmt"><dt><a href="/pkg/fmt/">fmt</a></dt> - <dd> - <p><!-- https://go.dev/issue/53435 --> - The <a href="/pkg/fmt/#Errorf"><code>Errorf</code></a> function supports multiple occurrences of - the <code>%w</code> format verb, returning an error that unwraps to the list of all arguments to <code>%w</code>. - </p> - <p><!-- https://go.dev/issue/51668, CL 400875 --> - The new <a href="/pkg/fmt/#FormatString"><code>FormatString</code></a> function recovers the - formatting directive corresponding to a <a href="/pkg/fmt/#State"><code>State</code></a>, - which can be useful in <a href="/pkg/fmt/#Formatter"><code>Formatter</code></a>. - implementations. - </p> - </dd> -</dl><!-- fmt --> - -<dl id="go/ast"><dt><a href="/pkg/go/ast/">go/ast</a></dt> - <dd> - <p><!-- CL 426091, https://go.dev/issue/50429 --> - The new <a href="/pkg/go/ast/#RangeStmt.Range"><code>RangeStmt.Range</code></a> field - records the position of the <code>range</code> keyword in a range statement. - </p> - <p><!-- CL 427955, https://go.dev/issue/53202 --> - The new <a href="/pkg/go/ast/#File.FileStart"><code>File.FileStart</code></a> - and <a href="/pkg/go/ast/#File.FileEnd"><code>File.FileEnd</code></a> fields - record the position of the start and end of the entire source file. - </p> - </dd> -</dl><!-- go/ast --> - -<dl id="go/token"><dt><a href="/pkg/go/token/">go/token</a></dt> - <dd> - <p><!-- CL 410114, https://go.dev/issue/53200 --> - The new <a href="/pkg/go/token/#FileSet.RemoveFile"><code>FileSet.RemoveFile</code></a> method - removes a file from a <code>FileSet</code>. - Long-running programs can use this to release memory associated - with files they no longer need. - </p> - </dd> -</dl><!-- go/token --> - -<dl id="go/types"><dt><a href="/pkg/go/types/">go/types</a></dt> - <dd> - <p><!-- CL 454575 --> - The new <a href="/pkg/go/types/#Satisfies"><code>Satisfies</code></a> function reports - whether a type satisfies a constraint. - This change aligns with the <a href="#language">new language semantics</a> - that distinguish satisfying a constraint from implementing an interface. - </p> - </dd> -</dl><!-- go/types --> - -<dl id="io"><dt><a href="/pkg/io/">io</a></dt> - <dd> - <p><!-- https://go.dev/issue/45899, CL 406776 --> - The new <a href="/pkg/io/#OffsetWriter"><code>OffsetWriter</code></a> wraps an underlying - <a href="/pkg/io/#WriterAt"><code>WriterAt</code></a> - and provides <code>Seek</code>, <code>Write</code>, and <code>WriteAt</code> methods - that adjust their effective file offset position by a fixed amount. - </p> - </dd> -</dl><!-- io --> - -<dl id="io/fs"><dt><a href="/pkg/io/fs/">io/fs</a></dt> - <dd> - <p><!-- CL 363814, https://go.dev/issue/47209 --> - The new error <a href="/pkg/io/fs/#SkipAll"><code>SkipAll</code></a> - terminates a <a href="/pkg/io/fs/#WalkDir"><code>WalkDir</code></a> - immediately but successfully. - </p> - </dd> -</dl><!-- io --> - -<dl id="math/big"><dt><a href="/pkg/math/big/">math/big</a></dt> - <dd> - <p><!-- https://go.dev/issue/52182 --> - The <a href="/pkg/math/big/">math/big</a> package's wide scope and - input-dependent timing make it ill-suited for implementing cryptography. - The cryptography packages in the standard library no longer call non-trivial - <a href="/pkg/math/big#Int">Int</a> methods on attacker-controlled inputs. - In the future, the determination of whether a bug in math/big is - considered a security vulnerability will depend on its wider impact on the - standard library. - </p> - </dd> -</dl><!-- math/big --> - -<dl id="math/rand"><dt><a href="/pkg/math/rand/">math/rand</a></dt> - <dd> - <p><!-- https://go.dev/issue/54880, CL 436955, https://go.dev/issue/56319 --> - The <a href="/pkg/math/rand/">math/rand</a> package now automatically seeds - the global random number generator - (used by top-level functions like <code>Float64</code> and <code>Int</code>) with a random value, - and the top-level <a href="/pkg/math/rand/#Seed"><code>Seed</code></a> function has been deprecated. - Programs that need a reproducible sequence of random numbers - should prefer to allocate their own random source, using <code>rand.New(rand.NewSource(seed))</code>. - </p> - <p> - Programs that need the earlier consistent global seeding behavior can set - <code>GODEBUG=randautoseed=0</code> in their environment. - </p> - <p><!-- https://go.dev/issue/20661 --> - The top-level <a href="/pkg/math/rand/#Read"><code>Read</code></a> function has been deprecated. - In almost all cases, <a href="/pkg/crypto/rand/#Read"><code>crypto/rand.Read</code></a> is more appropriate. - </p> - </dd> -</dl><!-- math/rand --> - -<dl id="mime"><dt><a href="/pkg/mime/">mime</a></dt> - <dd> - <p><!-- https://go.dev/issue/48866 --> - The <a href="/pkg/mime/#ParseMediaType"><code>ParseMediaType</code></a> function now allows duplicate parameter names, - so long as the values of the names are the same. - </p> - </dd> -</dl><!-- mime --> - -<dl id="mime/multipart"><dt><a href="/pkg/mime/multipart/">mime/multipart</a></dt> - <dd> - <p><!-- CL 431675 --> - Methods of the <a href="/pkg/mime/multipart/#Reader"><code>Reader</code></a> type now wrap errors - returned by the underlying <code>io.Reader</code>. - </p> - </dd> -</dl><!-- mime/multipart --> - -<dl id="net"><dt><a href="/pkg/net/">net</a></dt> - <dd> - <p><!-- https://go.dev/issue/50101, CL 446179 --> - The <a href="/pkg/net/#LookupCNAME"><code>LookupCNAME</code></a> - function now consistently returns the contents - of a <code>CNAME</code> record when one exists. Previously on Unix systems and - when using the pure Go resolver, <code>LookupCNAME</code> would return an error - if a <code>CNAME</code> record referred to a name that with no <code>A</code>, - <code>AAAA</code>, or <code>CNAME</code> record. This change modifies - <code>LookupCNAME</code> to match the previous behavior on Windows, - allowing <code>LookupCNAME</code> to succeed whenever a - <code>CNAME</code> exists. - </p> - - <p><!-- https://go.dev/issue/53482, CL 413454 --> - <a href="/pkg/net/#Interface.Flags"><code>Interface.Flags</code></a> now includes the new flag <code>FlagRunning</code>, - indicating an operationally active interface. An interface which is administratively - configured but not active (for example, because the network cable is not connected) - will have <code>FlagUp</code> set but not <code>FlagRunning</code>. - </p> - - <p><!-- https://go.dev/issue/55301, CL 444955 --> - The new <a href="/pkg/net/#Dialer.ControlContext"><code>Dialer.ControlContext</code></a> field contains a callback function - similar to the existing <a href="/pkg/net/#Dialer.Control"><code>Dialer.Control</code></a> hook, that additionally - accepts the dial context as a parameter. - <code>Control</code> is ignored when <code>ControlContext</code> is not nil. - </p> - - <p><!-- CL 428955 --> - The Go DNS resolver recognizes the <code>trust-ad</code> resolver option. - When <code>options trust-ad</code> is set in <code>resolv.conf</code>, - the Go resolver will set the AD bit in DNS queries. The resolver does not - make use of the AD bit in responses. - </p> - - <p><!-- CL 448075 --> - DNS resolution will detect changes to <code>/etc/nsswitch.conf</code> - and reload the file when it changes. Checks are made at most once every - five seconds, matching the previous handling of <code>/etc/hosts</code> - and <code>/etc/resolv.conf</code>. - </p> - </dd> -</dl><!-- net --> - -<dl id="net/http"><dt><a href="/pkg/net/http/">net/http</a></dt> - <dd> - <p><!-- https://go.dev/issue/51914 --> - The <a href="/pkg/net/http/#ResponseWriter.WriteHeader"><code>ResponseWriter.WriteHeader</code></a> function now supports sending - <code>1xx</code> status codes. - </p> - - <p><!-- https://go.dev/issue/41773, CL 356410 --> - The new <a href="/pkg/net/http/#Server.DisableGeneralOptionsHandler"><code>Server.DisableGeneralOptionsHandler</code></a> configuration setting - allows disabling the default <code>OPTIONS *</code> handler. - </p> - - <p><!-- https://go.dev/issue/54299, CL 447216 --> - The new <a href="/pkg/net/http/#Transport.OnProxyConnectResponse"><code>Transport.OnProxyConnectResponse</code></a> hook is called - when a <code>Transport</code> receives an HTTP response from a proxy - for a <code>CONNECT</code> request. - </p> - - <p><!-- https://go.dev/issue/53960, CL 418614 --> - The HTTP server now accepts HEAD requests containing a body, - rather than rejecting them as invalid. - </p> - - <p><!-- https://go.dev/issue/53896 --> - HTTP/2 stream errors returned by <code>net/http</code> functions may be converted - to a <a href="/pkg/golang.org/x/net/http2/#StreamError"><code>golang.org/x/net/http2.StreamError</code></a> using - <a href="/pkg/errors/#As"><code>errors.As</code></a>. - </p> - - <p><!-- https://go.dev/cl/397734 --> - Leading and trailing spaces are trimmed from cookie names, - rather than being rejected as invalid. - For example, a cookie setting of "name =value" - is now accepted as setting the cookie "name". - </p> - </dd> -</dl><!-- net/http --> - -<dl id="net/netip"><dt><a href="/pkg/net/netip/">net/netip</a></dt> - <dd> - <p><!-- https://go.dev/issue/51766, https://go.dev/issue/51777, CL 412475 --> - The new <a href="/pkg/net/netip/#IPv6LinkLocalAllRouters"><code>IPv6LinkLocalAllRouters</code></a> - and <a href="/pkg/net/netip/#IPv6Loopback"><code>IPv6Loopback</code></a> functions - are the <code>net/netip</code> equivalents of - <a href="/pkg/net/#IPv6loopback"><code>net.IPv6loopback</code></a> and - <a href="/pkg/net/#IPv6linklocalallrouters"><code>net.IPv6linklocalallrouters</code></a>. - </p> - </dd> -</dl><!-- net/netip --> - -<dl id="os"><dt><a href="/pkg/os/">os</a></dt> - <dd> - <p><!-- CL 448897 --> - On Windows, the name <code>NUL</code> is no longer treated as a special case in - <a href="/pkg/os/#Mkdir"><code>Mkdir</code></a> and - <a href="/pkg/os/#Stat"><code>Stat</code></a>. - </p> - <p><!-- https://go.dev/issue/52747, CL 405275 --> - On Windows, <a href="/pkg/os/#File.Stat"><code>File.Stat</code></a> - now uses the file handle to retrieve attributes when the file is a directory. - Previously it would use the path passed to - <a href="/pkg/os/#Open"><code>Open</code></a>, which may no longer be the file - represented by the file handle if the file has been moved or replaced. - This change modifies <code>Open</code> to open directories without the - <code>FILE_SHARE_DELETE</code> access, which match the behavior of regular files. - </p> - <p><!-- https://go.dev/issue/36019, CL 405275 --> - On Windows, <a href="/pkg/os/#File.Seek"><code>File.Seek</code></a> now supports - seeking to the beginning of a directory. - </p> - </dd> -</dl><!-- os --> - -<dl id="os/exec"><dt><a href="/pkg/os/exec/">os/exec</a></dt> - <dd> - <p><!-- https://go.dev/issue/50436, CL 401835 --> - The new <a href="/pkg/os/exec/#Cmd"><code>Cmd</code></a> fields - <a href="/pkg/os/exec/#Cmd.Cancel"><code>Cancel</code></a> and - <a href="/pkg/os/exec/#Cmd.WaitDelay"><code>WaitDelay</code></a> - specify the behavior of the <code>Cmd</code> when its associated - <code>Context</code> is canceled or its process exits with I/O pipes still - held open by a child process. - </p> - </dd> -</dl><!-- os/exec --> - -<dl id="path/filepath"><dt><a href="/pkg/path/filepath/">path/filepath</a></dt> - <dd> - <p><!-- CL 363814, https://go.dev/issue/47209 --> - The new error <a href="/pkg/path/filepath/#SkipAll"><code>SkipAll</code></a> - terminates a <a href="/pkg/path/filepath/#Walk"><code>Walk</code></a> - immediately but successfully. - </p> - <p><!-- https://go.dev/issue/56219, CL 449239 --> - The new <a href="/pkg/path/filepath/#IsLocal"><code>IsLocal</code></a> function reports whether a path is - lexically local to a directory. - For example, if <code>IsLocal(p)</code> is <code>true</code>, - then <code>Open(p)</code> will refer to a file that is lexically - within the subtree rooted at the current directory. - </p> - </dd> -</dl><!-- io --> - -<dl id="reflect"><dt><a href="/pkg/reflect/">reflect</a></dt> - <dd> - <p><!-- https://go.dev/issue/46746, CL 423794 --> - The new <a href="/pkg/reflect/#Value.Comparable"><code>Value.Comparable</code></a> and - <a href="/pkg/reflect/#Value.Equal"><code>Value.Equal</code></a> methods - can be used to compare two <code>Value</code>s for equality. - <code>Comparable</code> reports whether <code>Equal</code> is a valid operation for a given <code>Value</code> receiver. - </p> - - <p><!-- https://go.dev/issue/48000, CL 389635 --> - The new <a href="/pkg/reflect/#Value.Grow"><code>Value.Grow</code></a> method - extends a slice to guarantee space for another <code>n</code> elements. - </p> - - <p><!-- https://go.dev/issue/52376, CL 411476 --> - The new <a href="/pkg/reflect/#Value.SetZero"><code>Value.SetZero</code></a> method - sets a value to be the zero value for its type. - </p> - - <p><!-- CL 425184 --> - Go 1.18 introduced <a href="/pkg/reflect/#Value.SetIterKey"><code>Value.SetIterKey</code></a> - and <a href="/pkg/reflect/#Value.SetIterValue"><code>Value.SetIterValue</code></a> methods. - These are optimizations: <code>v.SetIterKey(it)</code> is meant to be equivalent to <code>v.Set(it.Key())</code>. - The implementations incorrectly omitted a check for use of unexported fields that was present in the unoptimized forms. - Go 1.20 corrects these methods to include the unexported field check. - </p> - </dd> -</dl><!-- reflect --> - -<dl id="regexp"><dt><a href="/pkg/regexp/">regexp</a></dt> - <dd> - <p><!-- CL 444817 --> - Go 1.19.2 and Go 1.18.7 included a security fix to the regular expression parser, - making it reject very large expressions that would consume too much memory. - Because Go patch releases do not introduce new API, - the parser returned <a href="/pkg/regexp/syntax/#ErrInternalError"><code>syntax.ErrInternalError</code></a> in this case. - Go 1.20 adds a more specific error, <a href="/pkg/regexp/syntax/#ErrLarge"><code>syntax.ErrLarge</code></a>, - which the parser now returns instead. - </p> - </dd> -</dl><!-- regexp --> - -<dl id="runtime/cgo"><dt><a href="/pkg/runtime/cgo/">runtime/cgo</a></dt> - <dd> - <p><!-- https://go.dev/issue/46731, CL 421879 --> - Go 1.20 adds new <a href="/pkg/runtime/cgo/#Incomplete"><code>Incomplete</code></a> marker type. - Code generated by cgo will use <code>cgo.Incomplete</code> to mark an incomplete C type. - </p> - </dd> -</dl><!-- runtime/cgo --> - -<dl id="runtime/metrics"><dt><a href="/pkg/runtime/metrics/">runtime/metrics</a></dt> - <dd> - <p><!-- https://go.dev/issue/47216, https://go.dev/issue/49881 --> - Go 1.20 adds new <a href="/pkg/runtime/metrics/#hdr-Supported_metrics">supported metrics</a>, - including the current <code>GOMAXPROCS</code> setting (<code>/sched/gomaxprocs:threads</code>), - the number of cgo calls executed (<code>/cgo/go-to-c-calls:calls</code>), - total mutex block time (<code>/sync/mutex/wait/total</code>), and various measures of time - spent in garbage collection. - </p> - - <p><!-- CL 427615 --> - Time-based histogram metrics are now less precise, but take up much less memory. - </p> - </dd> -</dl><!-- runtime/metrics --> - -<dl id="runtime/pprof"><dt><a href="/pkg/runtime/pprof/">runtime/pprof</a></dt> - <dd> - <p><!-- CL 443056 --> - Mutex profile samples are now pre-scaled, fixing an issue where old mutex profile - samples would be scaled incorrectly if the sampling rate changed during execution. - </p> - - <p><!-- CL 416975 --> - Profiles collected on Windows now include memory mapping information that fixes - symbolization issues for position-independent binaries. - </p> - </dd> -</dl><!-- runtime/pprof --> - -<dl id="runtime/trace"><dt><a href="/pkg/runtime/trace/">runtime/trace</a></dt> - <dd> - <p><!-- CL 447135, https://go.dev/issue/55022 --> - The garbage collector's background sweeper now yields less frequently, - resulting in many fewer extraneous events in execution traces. - </p> - </dd> -</dl><!-- runtime/trace --> - -<dl id="strings"><dt><a href="/pkg/strings/">strings</a></dt> - <dd> - <p><!-- CL 407176, https://go.dev/issue/42537 --> - The new - <a href="/pkg/strings/#CutPrefix"><code>CutPrefix</code></a> and - <a href="/pkg/strings/#CutSuffix"><code>CutSuffix</code></a> functions - are like <a href="/pkg/strings/#TrimPrefix"><code>TrimPrefix</code></a> - and <a href="/pkg/strings/#TrimSuffix"><code>TrimSuffix</code></a> - but also report whether the string was trimmed. - </p> - - <p><!-- CL 359675, https://go.dev/issue/45038 --> - The new <a href="/pkg/strings/#Clone"><code>Clone</code></a> function - allocates a copy of a string. - </p> - </dd> -</dl><!-- strings --> - -<dl id="sync"><dt><a href="/pkg/sync/">sync</a></dt> - <dd> - <p><!-- CL 399094, https://go.dev/issue/51972 --> - The new <a href="/pkg/sync/#Map"><code>Map</code></a> methods <a href="/pkg/sync/#Map.Swap"><code>Swap</code></a>, - <a href="/pkg/sync/#Map.CompareAndSwap"><code>CompareAndSwap</code></a>, and - <a href="/pkg/sync/#Map.CompareAndDelete"><code>CompareAndDelete</code></a> - allow existing map entries to be updated atomically. - </p> - </dd> -</dl><!-- sync --> - -<dl id="syscall"><dt><a href="/pkg/syscall/">syscall</a></dt> - <dd> - <p><!-- CL 411596 --> - On FreeBSD, compatibility shims needed for FreeBSD 11 and earlier have been removed. - </p> - <p><!-- CL 407574 --> - On Linux, additional <a href="/pkg/syscall/#CLONE_CLEAR_SIGHAND"><code>CLONE_*</code></a> constants - are defined for use with the <a href="/pkg/syscall/#SysProcAttr.Cloneflags"><code>SysProcAttr.Cloneflags</code></a> field. - </p> - <p><!-- CL 417695 --> - On Linux, the new <a href="/pkg/syscall/#SysProcAttr.CgroupFD"><code>SysProcAttr.CgroupFD</code></a> - and <a href="/pkg/syscall/#SysProcAttr.UseCgroupFD"><code>SysProcAttr.UseCgroupFD</code></a> fields - provide a way to place a child process into a specific cgroup. - </p> - </dd> -</dl><!-- syscall --> - -<dl id="testing"><dt><a href="/pkg/testing/">testing</a></dt> - <dd> - <p><!-- https://go.dev/issue/43620, CL 420254 --> - The new method <a href="/pkg/testing/#B.Elapsed"><code>B.Elapsed</code></a> - reports the current elapsed time of the benchmark, which may be useful for - calculating rates to report with <code>ReportMetric</code>. - </p> - </dd> -</dl><!-- testing --> - -<dl id="time"><dt><a href="/pkg/time/">time</a></dt> - <dd> - <p><!-- https://go.dev/issue/52746, CL 412495 --> - The new time layout constants <a href="/pkg/time/#DateTime"><code>DateTime</code></a>, - <a href="/pkg/time/#DateOnly"><code>DateOnly</code></a>, and - <a href="/pkg/time/#TimeOnly"><code>TimeOnly</code></a> - provide names for three of the most common layout strings used in a survey of public Go source code. - </p> - - <p><!-- CL 382734, https://go.dev/issue/50770 --> - The new <a href="/pkg/time/#Time.Compare"><code>Time.Compare</code></a> method - compares two times. - </p> - - <p><!-- CL 425037 --> - <a href="/pkg/time/#Parse"><code>Parse</code></a> - now ignores sub-nanosecond precision in its input, - instead of reporting those digits as an error. - </p> - - <p><!-- CL 444277 --> - The <a href="/pkg/time/#Time.MarshalJSON"><code>Time.MarshalJSON</code></a> method - is now more strict about adherence to RFC 3339. - </p> - </dd> -</dl><!-- time --> - -<dl id="unicode/utf16"><dt><a href="/pkg/unicode/utf16/">unicode/utf16</a></dt> - <dd> - <p><!-- https://go.dev/issue/51896, CL 409054 --> - The new <a href="/pkg/unicode/utf16/#AppendRune"><code>AppendRune</code></a> - function appends the UTF-16 encoding of a given rune to a uint16 slice, - analogous to <a href="/pkg/unicode/utf8/#AppendRune"><code>utf8.AppendRune</code></a>. - </p> - </dd> -</dl><!-- unicode/utf16 --> - -<!-- Silence false positives from x/build/cmd/relnote: --> -<!-- https://go.dev/issue/45964 was documented in Go 1.18 release notes but closed recently --> -<!-- https://go.dev/issue/52114 is an accepted proposal to add golang.org/x/net/http2.Transport.DialTLSContext; it's not a part of the Go release --> -<!-- CL 431335: cmd/api: make check pickier about api/*.txt --> -<!-- CL 447896 api: add newline to 55301.txt; modified api/next/55301.txt --> -<!-- CL 449215 api/next/54299: add missing newline; modified api/next/54299.txt --> -<!-- CL 433057 cmd: update vendored golang.org/x/tools for multiple error wrapping --> -<!-- CL 423362 crypto/internal/boring: update to newer boringcrypto, add arm64 --> -<!-- https://go.dev/issue/53481 x/cryptobyte ReadUint64, AddUint64 --> -<!-- https://go.dev/issue/51994 x/crypto/ssh --> -<!-- https://go.dev/issue/55358 x/exp/slices --> -<!-- https://go.dev/issue/54714 x/sys/unix --> -<!-- https://go.dev/issue/50035 https://go.dev/issue/54237 x/time/rate --> -<!-- CL 345488 strconv optimization --> -<!-- CL 428757 reflect deprecation, rolled back --> -<!-- https://go.dev/issue/49390 compile -l -N is fully supported --> -<!-- https://go.dev/issue/54619 x/tools --> -<!-- CL 448898 reverted --> -<!-- https://go.dev/issue/54850 x/net/http2 Transport.MaxReadFrameSize --> -<!-- https://go.dev/issue/56054 x/net/http2 SETTINGS_HEADER_TABLE_SIZE --> -<!-- CL 450375 reverted --> -<!-- CL 453259 tracking deprecations in api --> -<!-- CL 453260 tracking darwin port in api --> -<!-- CL 453615 fix deprecation comment in archive/tar --> -<!-- CL 453616 fix deprecation comment in archive/zip --> -<!-- CL 453617 fix deprecation comment in encoding/csv --> -<!-- https://go.dev/issue/54661 x/tools/go/analysis --> -<!-- CL 423359, https://go.dev/issue/51317 arena --> |