https://golang.org/doc/articles/c_go_cgo.html.

CFLAGS, CPPFLAGS, CXXFLAGS, FFLAGS and LDFLAGS may be defined with pseudo
#cgo directives within these comments to tweak the behavior of the C, C++
or Fortran compiler. Values defined in multiple directives are concatenated
together. The directive can include a list of build constraints limiting its
effect to systems satisfying one of the constraints

	LAX	R7, R8, (R9)          // eb87900000f7
	LAXG	R10, R11, (R12)       // ebbac00000e7
	LAO	R1, R2, (R3)          // eb21300000f6
	LAOG	R4, R5, (R6)          // eb54600000e6

	// load and store multiple
	LMG	n-8(SP), R3, R4         // eb34f0100004
	LMG	-5(R5), R3, R4          // eb345ffbff04
	LMY	n-8(SP), R3, R4         // 9834f010
	LMY	4096(R1), R3, R4        // eb3410000198

jumps to labels:
</p>

<pre>
label:
	MOVW $0, R1
	JMP label
</pre>

<p>
Each label is visible only within the function in which it is defined.
It is therefore permitted for multiple functions in a file to define
and use the same label names.
Direct jumps and call instructions can target text symbols,
such as <code>name(SB)</code>, but not offsets from symbols,
such as <code>name+4(SB)</code>.
</p>

// license that can be found in the LICENSE file.

package tar

import "strings"

// Format represents the tar archive format.
//
// The original tar format was introduced in Unix V7.
// Since then, there have been multiple competing formats attempting to
// standardize or extend the V7 format to overcome its limitations.
// The most common formats are the USTAR, PAX, and GNU formats,
// each with their own advantages and limitations.
//

it must not allow a single read to observe multiple values,
and it must not allow a single write to write multiple values.
</p>

<p>
All the following examples assume that `*p` and `*q` refer to
memory locations accessible to multiple goroutines.
</p>

<p>
Not introducing data races into race-free programs means not moving

type fileState interface {
	logicalRemaining() int64
	physicalRemaining() int64
}

// allowedFormats determines which formats can be used.
// The value returned is the logical OR of multiple possible formats.
// If the value is FormatUnknown, then the input Header cannot be encoded
// and an error is returned explaining why.
//
// As a by-product of checking the fields, this function returns paxHdrs, which

	bodyOffset, err := f.findBodyOffset()
	if err != nil {
		return
	}
	return f.headerOffset + bodyOffset, nil
}

// Open returns a [ReadCloser] that provides access to the [File]'s contents.
// Multiple files may be read concurrently.
func (f *File) Open() (io.ReadCloser, error) {
	bodyOffset, err := f.findBodyOffset()
	if err != nil {
		return nil, err
	}
	if strings.HasSuffix(f.Name, "/") {

		return 0, false
	}
	return r, true
}

// register parses a full register reference where there is no symbol present (as in 4(R0) or R(10) but not sym(SB))
// including forms involving multiple registers such as R1:R2.
func (p *Parser) register(name string, prefix rune) (r1, r2 int16, scale int8, ok bool) {
	// R1 or R(1) R1:R2 R1,R2 R1+R2, or R1*scale.
	r1, ok = p.registerReference(name)
	if !ok {
		return

# CL 134210043 archive/zip: add Writer.Flush, Brad Fitzpatrick <******@****.***>
pkg archive/zip, method (*Writer) Flush() error

# CL 97140043 compress/flate: add Reset() to allow reusing large buffers to compress multiple buffers, James Robinson <******@****.***>
pkg compress/flate, type Resetter interface { Reset }
pkg compress/flate, type Resetter interface, Reset(io.Reader, []uint8) error
pkg compress/zlib, type Resetter interface { Reset }

	buf.Grow(n)
	// Copy full pieces and fragment in.
	for _, fb := range full {
		buf.Write(fb)
	}
	buf.Write(frag)
	return buf.String(), err
}

// WriteTo implements io.WriterTo.
// This may make multiple calls to the [Reader.Read] method of the underlying [Reader].
// If the underlying reader supports the [Reader.WriteTo] method,
// this calls the underlying [Reader.WriteTo] without buffering.