errTagValueSpace  = errors.New("suspicious space in struct tag value")
	errTagSpace       = errors.New("key:\"value\" pairs not separated by spaces")
)

// validateStructTag parses the struct tag and returns an error if it is not
// in the canonical format, which is a space-separated list of key:"value"
// settings. The value may contain spaces.
func validateStructTag(tag string) error {

	// Determine and prepend leading space.
	i, j := 0, 0
	for j < len(src) && isSpace(src[j]) {
		if src[j] == '\n' {
			i = j + 1 // byte offset of last line in leading space
		}
		j++
	}
	var res []byte
	res = append(res, src[:i]...)

	// Determine and prepend indentation of first code line.
	// Spaces are ignored unless there are no tabs,
	// in which case spaces count as one tab.
	indent := 0

	// Determine and prepend leading space.
	i, j := 0, 0
	for j < len(src) && isSpace(src[j]) {
		if src[j] == '\n' {
			i = j + 1 // byte offset of last line in leading space
		}
		j++
	}
	var res []byte
	res = append(res, src[:i]...)

	// Determine and prepend indentation of first code line.
	// Spaces are ignored unless there are no tabs,
	// in which case spaces count as one tab.
	indent := 0

		fmtc, w := utf8.DecodeRuneInString(format[i:])

		// Space processing.
		// In the rest of this comment "space" means spaces other than newline.
		// Newline in the format matches input of zero or more spaces and then newline or end-of-input.
		// Spaces in the format before the newline are collapsed into the newline.
		// Spaces in the format after the newline match zero or more spaces after the corresponding input newline.

# Test that #cgo LDFLAGS are properly quoted.
# The #cgo LDFLAGS below should pass a string with spaces to -L,
# as though searching a directory with a space in its name.
# It should not pass --nosuchoption to the external linker.

[!cgo] skip

go build

[!exec:gccgo] skip

# TODO: remove once gccgo on builder is updated
[GOOS:aix] [GOARCH:ppc64] skip

go build -compiler gccgo

-- go.mod --
module m
-- cgo.go --
package main

! exists $WORK/log.txt
? go build -x
exists $WORK/log.txt
rm $WORK/log.txt

# TODO(#41400, #43078): when CC is set explicitly, it should be allowed to
# contain spaces separating arguments, and it should be possible to quote
# arguments with spaces (including the path), as in CGO_CFLAGS and other
# variables. For now, this doesn't work.
[!GOOS:windows] env CC=$WORK/'program files'/gcc
[GOOS:windows] env CC=$WORK\'program files'\gcc.bat

	// credElement is fetched first to skip replacing the space in access key.
	credElement := strings.TrimPrefix(strings.Split(strings.TrimSpace(v4Auth), ",")[0], signV4Algorithm)
	// Replace all spaced strings, some clients can send spaced
	// parameters and some won't. So we pro-actively remove any spaces
	// to make parsing easier.
	v4Auth = strings.ReplaceAll(v4Auth, " ", "")
	if v4Auth == "" {

	// and collapse consecutive internal spaces, tabs, and line endings to a single space.”
	s = trimSpaceTabNewline(s)
	var b strings.Builder
	space := false
	hi := false
	for i := 0; i < len(s); i++ {
		c := s[i]
		switch c {
		case ' ', '\t', '\n':
			space = true
			continue
		default:
			if space {
				b.WriteByte(' ')
				space = false

// characters include letters, marks, numbers, punctuation, symbols, and the
// ASCII space character, from categories [L], [M], [N], [P], [S] and the ASCII space
// character. This categorization is the same as [IsGraphic] except that the
// only spacing character is ASCII space, U+0020.
func IsPrint(r rune) bool {
	if uint32(r) <= MaxLatin1 {
		return properties[uint8(r)]&pp != 0
	}

	"author",
}

// Synopsis returns a cleaned version of the first sentence in text.
// That sentence ends after the first period followed by space and not
// preceded by exactly one uppercase letter, or at the first paragraph break.
// The result string has no \n, \r, or \t characters and uses only single
// spaces between words. If text starts with any of the [IllegalPrefixes],
// the result is the empty string.