func C.GoBytes(unsafe.Pointer, C.int) []byte

As a special case, C.malloc does not call the C library malloc directly
but instead calls a Go helper function that wraps the C library malloc
but guarantees never to return nil. If C's malloc indicates out of memory,
the helper function crashes the program, like when Go itself runs out
of memory. Because C.malloc cannot fail, it has no two-result form
that returns errno.

}

func (w *teststringwriter) WriteString(s string) (int, error) {
	w.writeString += s
	return len(s), nil
}

func (w *teststringwriter) check(t *testing.T, write, writeString string) {
	t.Helper()
	if w.write != write {
		t.Errorf("write: expected %q, got %q", write, w.write)
	}
	if w.writeString != writeString {
		t.Errorf("writeString: expected %q, got %q", writeString, w.writeString)
	}
}

those are treated as two code points.  For simplicity, this document
will use the unqualified term <i>character</i> to refer to a Unicode code point
in the source text.
</p>
<p>
Each code point is distinct; for instance, upper and lower case letters
are different characters.
</p>
<p>
Implementation restriction: For compatibility with other tools, a
compiler may disallow the NUL character (U+0000) in the source text.
</p>
<p>

pkg testing, method (*F) Failed() bool
pkg testing, method (*F) Fatal(...interface{})
pkg testing, method (*F) Fatalf(string, ...interface{})
pkg testing, method (*F) Fuzz(interface{})
pkg testing, method (*F) Helper()
pkg testing, method (*F) Log(...interface{})
pkg testing, method (*F) Logf(string, ...interface{})
pkg testing, method (*F) Name() string
pkg testing, method (*F) Setenv(string, string)

pkg syscall, type RawConn interface, Read(func(uintptr) bool) error
pkg syscall, type RawConn interface, Write(func(uintptr) bool) error
pkg testing, method (*B) Helper()
pkg testing, method (*T) Helper()
pkg testing, type TB interface, Helper()
pkg time, method (Duration) Round(Duration) Duration

			removeTag := func(v uint64) uint64 { return v }
			if goarch == "arm64" {
				for i := range symtab {
					if symtab[i].Name == "__hwasan_init" {
						// -fsanitize=hwaddress on ARM
						// uses the upper byte of a
						// memory address as a hardware
						// tag. Remove it so that
						// we can find the associated
						// data.
						removeTag = func(v uint64) uint64 { return v &^ (0xff << (64 - 8)) }

	os.Setenv("GO_ADDR2LINETEST_IS_ADDR2LINE", "1") // Set for subprocesses to inherit.
	os.Exit(m.Run())
}

// addr2linePath returns the path to the "addr2line" binary to run.
func addr2linePath(t testing.TB) string {
	t.Helper()
	testenv.MustHaveExec(t)

	addr2linePathOnce.Do(func() {
		addr2lineExePath, addr2linePathErr = os.Executable()
	})
	if addr2linePathErr != nil {
		t.Fatal(addr2linePathErr)
	}
	return addr2lineExePath
}

//	string encoding   |  ASCII |     UTF-8 |    binary
//	sub-second times  |     no |       yes |        no
//	sparse files      |     no |       yes |       yes
//
// The table's upper portion shows the [Header] fields, where each format reports
// the maximum number of bytes allowed for each string field and
// the integer type used to store each numeric field

such as <code>name(SB)</code>, but not offsets from symbols,
such as <code>name+4(SB)</code>.
</p>

<p>
Instructions, registers, and assembler directives are always in UPPER CASE to remind you
that assembly programming is a fraught endeavor.
(Exception: the <code>g</code> register renaming on ARM.)
</p>

<p>
In Go object files and binaries, the full name of a symbol is the

// most-significant bit of the highest word, map to the full range of all
// 128 ASCII characters. The 128-bits of the upper 16 bytes will be zeroed,
// ensuring that any non-ASCII character will be reported as not in the set.
// This allocates a total of 32 bytes even though the upper half
// is unused to avoid bounds checks in asciiSet.contains.
type asciiSet [8]uint32