## Ports {#ports}

### Darwin {#darwin}

<!-- go.dev/issue/64207 -->
As [announced](go1.22#darwin) in the Go 1.22 release notes,
Go 1.23 requires macOS 11 Big Sur or later;
support for previous versions has been discontinued.

### Wasm {#wasm}

<!-- go.dev/issue/63718 -->
The `go_wasip1_wasm_exec` script in `GOROOT/misc/wasm` has dropped support

		// say "pkg syscall (darwin-amd64), type RawSockaddrInet6 struct" is missing.
		// See https://go.dev/issue/4303.
		{
			name: "contexts reconverging after api/next/* update",
			features: []string{
				"A",
				"pkg syscall, type RawSockaddrInet6 struct",
			},
			required: []string{
				"A",
				"pkg syscall (darwin-amd64), type RawSockaddrInet6 struct", // api/go1.n.txt

to Go.

# Special cases

A few special C types which would normally be represented by a pointer
type in Go are instead represented by a uintptr. Those include:

1. The *Ref types on Darwin, rooted at CoreFoundation's CFTypeRef type.

2. The object types from Java's JNI interface:

	jobject
	jclass
	jthrowable
	jstring
	jarray
	jbooleanArray
	jbyteArray
	jcharArray

</p>

<h4 id="Type_switches">Type switches</h4>

<p>
A type switch compares types rather than values. It is otherwise similar
to an expression switch. It is marked by a special switch expression that
has the form of a <a href="#Type_assertions">type assertion</a>
using the keyword <code>type</code> rather than an actual type:
</p>

<pre>
switch x.(type) {
// cases

Atlantic/Faroe Atlantic/Jan_Mayen Atlantic/Madeira Atlantic/Reykjavik Atlantic/South_Georgia Atlantic/St_Helena Atlantic/Stanley Australia/ACT Australia/Adelaide Australia/Brisbane Australia/Broken_Hill Australia/Canberra Australia/Currie Australia/Darwin Australia/Eucla Australia/Hobart Australia/LHI Australia/Lindeman Australia/Lord_Howe Australia/Melbourne Australia/NSW Australia/North Australia/Perth Australia/Queensland Australia/South Australia/Sydney Australia/Tasmania Australia/Victoria Australia/West...

</p>

<p>
A data symbol marked with the <code>NOPTR</code> flag (see above)
is treated as containing no pointers to runtime-allocated data.
A data symbol with the <code>RODATA</code> flag
is allocated in read-only memory and is therefore treated
as implicitly marked <code>NOPTR</code>.
A data symbol with a total size smaller than a pointer
is also treated as implicitly marked <code>NOPTR</code>.

}

func TestZip64EdgeCase(t *testing.T) {
	if testing.Short() {
		t.Skip("slow test; skipping")
	}
	t.Parallel()
	// Test a zip file with uncompressed size 0xFFFFFFFF.
	// That's the magic marker for a 64-bit file, so even though
	// it fits in a 32-bit field we must use the 64-bit field.
	// Go 1.5 and earlier got this wrong,
	// writing an invalid zip file.

</p>

<h4 id="Type_switches">Type switches</h4>

<p>
A type switch compares types rather than values. It is otherwise similar
to an expression switch. It is marked by a special switch expression that
has the form of a <a href="#Type_assertions">type assertion</a>
using the keyword <code>type</code> rather than an actual type:
</p>

<pre>
switch x.(type) {
// cases

	{GOOS: "linux", GOARCH: "amd64"},
	{GOOS: "linux", GOARCH: "arm", CgoEnabled: true},
	{GOOS: "linux", GOARCH: "arm"},
	{GOOS: "darwin", GOARCH: "amd64", CgoEnabled: true},
	{GOOS: "darwin", GOARCH: "amd64"},
	{GOOS: "darwin", GOARCH: "arm64", CgoEnabled: true},
	{GOOS: "darwin", GOARCH: "arm64"},
	{GOOS: "windows", GOARCH: "amd64"},
	{GOOS: "windows", GOARCH: "386"},
	{GOOS: "freebsd", GOARCH: "386", CgoEnabled: true},

// Read reads from the current file in the tar archive.
// It returns (0, io.EOF) when it reaches the end of that file,
// until [Next] is called to advance to the next file.
//
// If the current file is sparse, then the regions marked as a hole
// are read back as NUL-bytes.
//
// Calling Read on special types like [TypeLink], [TypeSymlink], [TypeChar],
// [TypeBlock], [TypeDir], and [TypeFifo] returns (0, [io.EOF]) regardless of what