well as the system-specific header locations and system-specific
pre-#defined macros. This is certainly possible to do, but it is an
enormous amount of work.

Cgo takes a different approach. It determines the meaning of C
identifiers not by parsing C code but by feeding carefully constructed
programs into the system C compiler and interpreting the generated

					add: (a, b) => a + b,
				},
				gojs: {
					// Go's SP does not change as long as no Go code is running. Some operations (e.g. calls, getters and setters)
					// may synchronously trigger a Go event handler. This makes Go code get executed in the middle of the imported
					// function. A goroutine can switch to a new stack if the current stack is too small (see morestack function).

In each case the value of the literal is the value represented by
the digits in the corresponding base.
</p>

<p>
Although these representations all result in an integer, they have
different valid ranges.  Octal escapes must represent a value between
0 and 255 inclusive.  Hexadecimal escapes satisfy this condition
by construction. The escapes <code>\u</code> and <code>\U</code>

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package cgotest

import (
	"io"
	"os"
	"path/filepath"
	"strings"
)

// OverlayDir makes a minimal-overhead copy of srcRoot in which new files may be added.
func OverlayDir(dstRoot, srcRoot string) error {
	dstRoot = filepath.Clean(dstRoot)
	if err := os.MkdirAll(dstRoot, 0777); err != nil {
		return err
	}

// using octal encoding with the appropriate NUL terminator.
func fitsInOctal(n int, x int64) bool {
	octBits := uint(n-1) * 3
	return x >= 0 && (n >= 22 || x < 1<<octBits)
}

// parsePAXTime takes a string of the form %d.%d as described in the PAX
// specification. Note that this implementation allows for negative timestamps,
// which is allowed for by the PAX specification, but not always portable.

	slice, err := b.readSlice(delim)
	return string(slice), err
}

// NewBuffer creates and initializes a new [Buffer] using buf as its
// initial contents. The new [Buffer] takes ownership of buf, and the
// caller should not use buf after this call. NewBuffer is intended to
// prepare a [Buffer] to read existing data. It can also be used to set

  x.go:3		0x1050203		e83882ffff		CALL runtime.morestack_noctxt(SB)
  x.go:3		0x1050208		ebb6			JMP main.main(SB)
</pre>

<h3 id="constants">Constants</h3>

<p>
Although the assembler takes its guidance from the Plan 9 assemblers,
it is a distinct program, so there are some differences.
One is in constant evaluation.
Constant expressions in the assembler are parsed using Go's operator

			// Drop misaligned fields, the same way we drop integer bit fields.
			// The goal is to make available what can be made available.
			// Otherwise one bad and unneeded field in an otherwise okay struct
			// makes the whole program not compile. Much of the time these
			// structs are in system headers that cannot be corrected.
			continue
		}

		// Round off up to talign, assumed to be a power of 2.

	// Since ZIP lacked high precision timestamps (nor an official specification
	// of the timezone used for the date fields), many competing extra fields
	// have been invented. Pervasive use effectively makes them "official".
	//
	// See http://mdfs.net/Docs/Comp/Archiving/Zip/ExtraField
	zip64ExtraID       = 0x0001 // Zip64 extended information
	ntfsExtraID        = 0x000a // NTFS
	unixExtraID        = 0x000d // UNIX

and the [go command documentation](/cmd/go#hdr-Build_and_test_caching).

### Go 1.23

Go 1.23 changed the channels created by package time to be unbuffered
(synchronous), which makes correct use of the [`Timer.Stop`](/pkg/time/#Timer.Stop)
and [`Timer.Reset`](/pkg/time/#Timer.Reset) method results much easier.
The [`asynctimerchan` setting](/pkg/time/#NewTimer) disables this change.