package runtime
import (
- "runtime/internal/atomic"
+ "internal/abi"
+ "internal/bytealg"
+ "internal/goarch"
"unsafe"
)
return a[idx]
}
s, b := rawstringtmp(buf, l)
- l = 0
for _, x := range a {
- copy(b[l:], x)
- l += len(x)
+ copy(b, x)
+ b = b[len(x):]
}
return s
}
-func concatstring2(buf *tmpBuf, a [2]string) string {
- return concatstrings(buf, a[:])
+func concatstring2(buf *tmpBuf, a0, a1 string) string {
+ return concatstrings(buf, []string{a0, a1})
}
-func concatstring3(buf *tmpBuf, a [3]string) string {
- return concatstrings(buf, a[:])
+func concatstring3(buf *tmpBuf, a0, a1, a2 string) string {
+ return concatstrings(buf, []string{a0, a1, a2})
}
-func concatstring4(buf *tmpBuf, a [4]string) string {
- return concatstrings(buf, a[:])
+func concatstring4(buf *tmpBuf, a0, a1, a2, a3 string) string {
+ return concatstrings(buf, []string{a0, a1, a2, a3})
}
-func concatstring5(buf *tmpBuf, a [5]string) string {
- return concatstrings(buf, a[:])
+func concatstring5(buf *tmpBuf, a0, a1, a2, a3, a4 string) string {
+ return concatstrings(buf, []string{a0, a1, a2, a3, a4})
}
+// slicebytetostring converts a byte slice to a string.
+// It is inserted by the compiler into generated code.
+// ptr is a pointer to the first element of the slice;
+// n is the length of the slice.
// Buf is a fixed-size buffer for the result,
// it is not nil if the result does not escape.
-func slicebytetostring(buf *tmpBuf, b []byte) string {
- l := len(b)
- if l == 0 {
+func slicebytetostring(buf *tmpBuf, ptr *byte, n int) string {
+ if n == 0 {
// Turns out to be a relatively common case.
// Consider that you want to parse out data between parens in "foo()bar",
// you find the indices and convert the subslice to string.
return ""
}
- if raceenabled && l > 0 {
- racereadrangepc(unsafe.Pointer(&b[0]),
- uintptr(l),
- getcallerpc(unsafe.Pointer(&buf)),
- funcPC(slicebytetostring))
+ if raceenabled {
+ racereadrangepc(unsafe.Pointer(ptr),
+ uintptr(n),
+ getcallerpc(),
+ abi.FuncPCABIInternal(slicebytetostring))
}
- if msanenabled && l > 0 {
- msanread(unsafe.Pointer(&b[0]), uintptr(l))
+ if msanenabled {
+ msanread(unsafe.Pointer(ptr), uintptr(n))
}
- s, c := rawstringtmp(buf, l)
- copy(c, b)
- return s
+ if asanenabled {
+ asanread(unsafe.Pointer(ptr), uintptr(n))
+ }
+ if n == 1 {
+ p := unsafe.Pointer(&staticuint64s[*ptr])
+ if goarch.BigEndian {
+ p = add(p, 7)
+ }
+ return unsafe.String((*byte)(p), 1)
+ }
+
+ var p unsafe.Pointer
+ if buf != nil && n <= len(buf) {
+ p = unsafe.Pointer(buf)
+ } else {
+ p = mallocgc(uintptr(n), nil, false)
+ }
+ memmove(p, unsafe.Pointer(ptr), uintptr(n))
+ return unsafe.String((*byte)(p), n)
}
// stringDataOnStack reports whether the string's data is
// stored on the current goroutine's stack.
func stringDataOnStack(s string) bool {
- ptr := uintptr(stringStructOf(&s).str)
+ ptr := uintptr(unsafe.Pointer(unsafe.StringData(s)))
stk := getg().stack
return stk.lo <= ptr && ptr < stk.hi
}
func rawstringtmp(buf *tmpBuf, l int) (s string, b []byte) {
if buf != nil && l <= len(buf) {
b = buf[:l]
- s = slicebytetostringtmp(b)
+ s = slicebytetostringtmp(&b[0], len(b))
} else {
s, b = rawstring(l)
}
return
}
-func slicebytetostringtmp(b []byte) string {
- // Return a "string" referring to the actual []byte bytes.
- // This is only for use by internal compiler optimizations
- // that know that the string form will be discarded before
- // the calling goroutine could possibly modify the original
- // slice or synchronize with another goroutine.
- // First such case is a m[string(k)] lookup where
- // m is a string-keyed map and k is a []byte.
- // Second such case is "<"+string(b)+">" concatenation where b is []byte.
- // Third such case is string(b)=="foo" comparison where b is []byte.
-
- if raceenabled && len(b) > 0 {
- racereadrangepc(unsafe.Pointer(&b[0]),
- uintptr(len(b)),
- getcallerpc(unsafe.Pointer(&b)),
- funcPC(slicebytetostringtmp))
- }
- if msanenabled && len(b) > 0 {
- msanread(unsafe.Pointer(&b[0]), uintptr(len(b)))
- }
- return *(*string)(unsafe.Pointer(&b))
+// slicebytetostringtmp returns a "string" referring to the actual []byte bytes.
+//
+// Callers need to ensure that the returned string will not be used after
+// the calling goroutine modifies the original slice or synchronizes with
+// another goroutine.
+//
+// The function is only called when instrumenting
+// and otherwise intrinsified by the compiler.
+//
+// Some internal compiler optimizations use this function.
+// - Used for m[T1{... Tn{..., string(k), ...} ...}] and m[string(k)]
+// where k is []byte, T1 to Tn is a nesting of struct and array literals.
+// - Used for "<"+string(b)+">" concatenation where b is []byte.
+// - Used for string(b)=="foo" comparison where b is []byte.
+func slicebytetostringtmp(ptr *byte, n int) string {
+ if raceenabled && n > 0 {
+ racereadrangepc(unsafe.Pointer(ptr),
+ uintptr(n),
+ getcallerpc(),
+ abi.FuncPCABIInternal(slicebytetostringtmp))
+ }
+ if msanenabled && n > 0 {
+ msanread(unsafe.Pointer(ptr), uintptr(n))
+ }
+ if asanenabled && n > 0 {
+ asanread(unsafe.Pointer(ptr), uintptr(n))
+ }
+ return unsafe.String(ptr, n)
}
func stringtoslicebyte(buf *tmpBuf, s string) []byte {
var b []byte
if buf != nil && len(s) <= len(buf) {
- b = buf[:len(s):len(s)]
+ *buf = tmpBuf{}
+ b = buf[:len(s)]
} else {
b = rawbyteslice(len(s))
}
return b
}
-func stringtoslicebytetmp(s string) []byte {
- // Return a slice referring to the actual string bytes.
- // This is only for use by internal compiler optimizations
- // that know that the slice won't be mutated.
- // The only such case today is:
- // for i, c := range []byte(str)
-
- str := stringStructOf(&s)
- ret := slice{array: unsafe.Pointer(str.str), len: str.len, cap: str.len}
- return *(*[]byte)(unsafe.Pointer(&ret))
-}
-
func stringtoslicerune(buf *[tmpStringBufSize]rune, s string) []rune {
// two passes.
// unlike slicerunetostring, no race because strings are immutable.
n := 0
- t := s
- for len(s) > 0 {
- _, k := charntorune(s)
- s = s[k:]
+ for range s {
n++
}
+
var a []rune
if buf != nil && n <= len(buf) {
- a = buf[:n:n]
+ *buf = [tmpStringBufSize]rune{}
+ a = buf[:n]
} else {
a = rawruneslice(n)
}
+
n = 0
- for len(t) > 0 {
- r, k := charntorune(t)
- t = t[k:]
+ for _, r := range s {
a[n] = r
n++
}
if raceenabled && len(a) > 0 {
racereadrangepc(unsafe.Pointer(&a[0]),
uintptr(len(a))*unsafe.Sizeof(a[0]),
- getcallerpc(unsafe.Pointer(&buf)),
- funcPC(slicerunetostring))
+ getcallerpc(),
+ abi.FuncPCABIInternal(slicerunetostring))
}
if msanenabled && len(a) > 0 {
msanread(unsafe.Pointer(&a[0]), uintptr(len(a))*unsafe.Sizeof(a[0]))
}
+ if asanenabled && len(a) > 0 {
+ asanread(unsafe.Pointer(&a[0]), uintptr(len(a))*unsafe.Sizeof(a[0]))
+ }
var dum [4]byte
size1 := 0
for _, r := range a {
- size1 += runetochar(dum[:], r)
+ size1 += encoderune(dum[:], r)
}
s, b := rawstringtmp(buf, size1+3)
size2 := 0
if size2 >= size1 {
break
}
- size2 += runetochar(b[size2:], r)
+ size2 += encoderune(b[size2:], r)
}
return s[:size2]
}
return (*stringStruct)(unsafe.Pointer(sp))
}
-func intstring(buf *[4]byte, v int64) string {
- var s string
+func intstring(buf *[4]byte, v int64) (s string) {
var b []byte
if buf != nil {
b = buf[:]
- s = slicebytetostringtmp(b)
+ s = slicebytetostringtmp(&b[0], len(b))
} else {
s, b = rawstring(4)
}
- n := runetochar(b, rune(v))
- return s[:n]
-}
-
-// stringiter returns the index of the next
-// rune after the rune that starts at s[k].
-func stringiter(s string, k int) int {
- if k >= len(s) {
- // 0 is end of iteration
- return 0
- }
-
- c := s[k]
- if c < runeself {
- return k + 1
+ if int64(rune(v)) != v {
+ v = runeError
}
-
- // multi-char rune
- _, n := charntorune(s[k:])
- return k + n
-}
-
-// stringiter2 returns the rune that starts at s[k]
-// and the index where the next rune starts.
-func stringiter2(s string, k int) (int, rune) {
- if k >= len(s) {
- // 0 is end of iteration
- return 0, 0
- }
-
- c := s[k]
- if c < runeself {
- return k + 1, rune(c)
- }
-
- // multi-char rune
- r, n := charntorune(s[k:])
- return k + n, r
+ n := encoderune(b, rune(v))
+ return s[:n]
}
// rawstring allocates storage for a new string. The returned
// The storage is not zeroed. Callers should use
// b to set the string contents and then drop b.
func rawstring(size int) (s string, b []byte) {
- p := mallocgc(uintptr(size), nil, flagNoScan|flagNoZero)
-
- stringStructOf(&s).str = p
- stringStructOf(&s).len = size
-
- *(*slice)(unsafe.Pointer(&b)) = slice{p, size, size}
-
- for {
- ms := maxstring
- if uintptr(size) <= uintptr(ms) || atomic.Casuintptr((*uintptr)(unsafe.Pointer(&maxstring)), uintptr(ms), uintptr(size)) {
- return
- }
- }
+ p := mallocgc(uintptr(size), nil, false)
+ return unsafe.String((*byte)(p), size), unsafe.Slice((*byte)(p), size)
}
// rawbyteslice allocates a new byte slice. The byte slice is not zeroed.
func rawbyteslice(size int) (b []byte) {
- cap := roundupsize(uintptr(size))
- p := mallocgc(cap, nil, flagNoScan|flagNoZero)
+ cap := roundupsize(uintptr(size), true)
+ p := mallocgc(cap, nil, false)
if cap != uintptr(size) {
- memclr(add(p, uintptr(size)), cap-uintptr(size))
+ memclrNoHeapPointers(add(p, uintptr(size)), cap-uintptr(size))
}
*(*slice)(unsafe.Pointer(&b)) = slice{p, size, int(cap)}
// rawruneslice allocates a new rune slice. The rune slice is not zeroed.
func rawruneslice(size int) (b []rune) {
- if uintptr(size) > _MaxMem/4 {
+ if uintptr(size) > maxAlloc/4 {
throw("out of memory")
}
- mem := roundupsize(uintptr(size) * 4)
- p := mallocgc(mem, nil, flagNoScan|flagNoZero)
+ mem := roundupsize(uintptr(size)*4, true)
+ p := mallocgc(mem, nil, false)
if mem != uintptr(size)*4 {
- memclr(add(p, uintptr(size)*4), mem-uintptr(size)*4)
+ memclrNoHeapPointers(add(p, uintptr(size)*4), mem-uintptr(size)*4)
}
*(*slice)(unsafe.Pointer(&b)) = slice{p, size, int(mem / 4)}
}
// used by cmd/cgo
-func gobytes(p *byte, n int) []byte {
+func gobytes(p *byte, n int) (b []byte) {
if n == 0 {
return make([]byte, 0)
}
- x := make([]byte, n)
- memmove(unsafe.Pointer(&x[0]), unsafe.Pointer(p), uintptr(n))
- return x
+
+ if n < 0 || uintptr(n) > maxAlloc {
+ panic(errorString("gobytes: length out of range"))
+ }
+
+ bp := mallocgc(uintptr(n), nil, false)
+ memmove(bp, unsafe.Pointer(p), uintptr(n))
+
+ *(*slice)(unsafe.Pointer(&b)) = slice{bp, n, n}
+ return
}
+// This is exported via linkname to assembly in syscall (for Plan9).
+//
+//go:linkname gostring
func gostring(p *byte) string {
l := findnull(p)
if l == 0 {
return s
}
+// internal_syscall_gostring is a version of gostring for internal/syscall/unix.
+//
+//go:linkname internal_syscall_gostring internal/syscall/unix.gostring
+func internal_syscall_gostring(p *byte) string {
+ return gostring(p)
+}
+
func gostringn(p *byte, l int) string {
if l == 0 {
return ""
return s
}
-func index(s, t string) int {
- if len(t) == 0 {
- return 0
+func hasPrefix(s, prefix string) bool {
+ return len(s) >= len(prefix) && s[:len(prefix)] == prefix
+}
+
+func hasSuffix(s, suffix string) bool {
+ return len(s) >= len(suffix) && s[len(s)-len(suffix):] == suffix
+}
+
+const (
+ maxUint64 = ^uint64(0)
+ maxInt64 = int64(maxUint64 >> 1)
+)
+
+// atoi64 parses an int64 from a string s.
+// The bool result reports whether s is a number
+// representable by a value of type int64.
+func atoi64(s string) (int64, bool) {
+ if s == "" {
+ return 0, false
+ }
+
+ neg := false
+ if s[0] == '-' {
+ neg = true
+ s = s[1:]
}
+
+ un := uint64(0)
for i := 0; i < len(s); i++ {
- if s[i] == t[0] && hasprefix(s[i:], t) {
- return i
+ c := s[i]
+ if c < '0' || c > '9' {
+ return 0, false
+ }
+ if un > maxUint64/10 {
+ // overflow
+ return 0, false
}
+ un *= 10
+ un1 := un + uint64(c) - '0'
+ if un1 < un {
+ // overflow
+ return 0, false
+ }
+ un = un1
+ }
+
+ if !neg && un > uint64(maxInt64) {
+ return 0, false
}
- return -1
+ if neg && un > uint64(maxInt64)+1 {
+ return 0, false
+ }
+
+ n := int64(un)
+ if neg {
+ n = -n
+ }
+
+ return n, true
}
-func contains(s, t string) bool {
- return index(s, t) >= 0
+// atoi is like atoi64 but for integers
+// that fit into an int.
+func atoi(s string) (int, bool) {
+ if n, ok := atoi64(s); n == int64(int(n)) {
+ return int(n), ok
+ }
+ return 0, false
}
-func hasprefix(s, t string) bool {
- return len(s) >= len(t) && s[:len(t)] == t
+// atoi32 is like atoi but for integers
+// that fit into an int32.
+func atoi32(s string) (int32, bool) {
+ if n, ok := atoi64(s); n == int64(int32(n)) {
+ return int32(n), ok
+ }
+ return 0, false
}
-func atoi(s string) int {
- n := 0
- for len(s) > 0 && '0' <= s[0] && s[0] <= '9' {
- n = n*10 + int(s[0]) - '0'
- s = s[1:]
+// parseByteCount parses a string that represents a count of bytes.
+//
+// s must match the following regular expression:
+//
+// ^[0-9]+(([KMGT]i)?B)?$
+//
+// In other words, an integer byte count with an optional unit
+// suffix. Acceptable suffixes include one of
+// - KiB, MiB, GiB, TiB which represent binary IEC/ISO 80000 units, or
+// - B, which just represents bytes.
+//
+// Returns an int64 because that's what its callers want and receive,
+// but the result is always non-negative.
+func parseByteCount(s string) (int64, bool) {
+ // The empty string is not valid.
+ if s == "" {
+ return 0, false
}
- return n
+ // Handle the easy non-suffix case.
+ last := s[len(s)-1]
+ if last >= '0' && last <= '9' {
+ n, ok := atoi64(s)
+ if !ok || n < 0 {
+ return 0, false
+ }
+ return n, ok
+ }
+ // Failing a trailing digit, this must always end in 'B'.
+ // Also at this point there must be at least one digit before
+ // that B.
+ if last != 'B' || len(s) < 2 {
+ return 0, false
+ }
+ // The one before that must always be a digit or 'i'.
+ if c := s[len(s)-2]; c >= '0' && c <= '9' {
+ // Trivial 'B' suffix.
+ n, ok := atoi64(s[:len(s)-1])
+ if !ok || n < 0 {
+ return 0, false
+ }
+ return n, ok
+ } else if c != 'i' {
+ return 0, false
+ }
+ // Finally, we need at least 4 characters now, for the unit
+ // prefix and at least one digit.
+ if len(s) < 4 {
+ return 0, false
+ }
+ power := 0
+ switch s[len(s)-3] {
+ case 'K':
+ power = 1
+ case 'M':
+ power = 2
+ case 'G':
+ power = 3
+ case 'T':
+ power = 4
+ default:
+ // Invalid suffix.
+ return 0, false
+ }
+ m := uint64(1)
+ for i := 0; i < power; i++ {
+ m *= 1024
+ }
+ n, ok := atoi64(s[:len(s)-3])
+ if !ok || n < 0 {
+ return 0, false
+ }
+ un := uint64(n)
+ if un > maxUint64/m {
+ // Overflow.
+ return 0, false
+ }
+ un *= m
+ if un > uint64(maxInt64) {
+ // Overflow.
+ return 0, false
+ }
+ return int64(un), true
}
//go:nosplit
if s == nil {
return 0
}
- p := (*[_MaxMem/2 - 1]byte)(unsafe.Pointer(s))
- l := 0
- for p[l] != 0 {
- l++
+
+ // Avoid IndexByteString on Plan 9 because it uses SSE instructions
+ // on x86 machines, and those are classified as floating point instructions,
+ // which are illegal in a note handler.
+ if GOOS == "plan9" {
+ p := (*[maxAlloc/2 - 1]byte)(unsafe.Pointer(s))
+ l := 0
+ for p[l] != 0 {
+ l++
+ }
+ return l
+ }
+
+ // pageSize is the unit we scan at a time looking for NULL.
+ // It must be the minimum page size for any architecture Go
+ // runs on. It's okay (just a minor performance loss) if the
+ // actual system page size is larger than this value.
+ const pageSize = 4096
+
+ offset := 0
+ ptr := unsafe.Pointer(s)
+ // IndexByteString uses wide reads, so we need to be careful
+ // with page boundaries. Call IndexByteString on
+ // [ptr, endOfPage) interval.
+ safeLen := int(pageSize - uintptr(ptr)%pageSize)
+
+ for {
+ t := *(*string)(unsafe.Pointer(&stringStruct{ptr, safeLen}))
+ // Check one page at a time.
+ if i := bytealg.IndexByteString(t, 0); i != -1 {
+ return offset + i
+ }
+ // Move to next page
+ ptr = unsafe.Pointer(uintptr(ptr) + uintptr(safeLen))
+ offset += safeLen
+ safeLen = pageSize
}
- return l
}
func findnullw(s *uint16) int {
if s == nil {
return 0
}
- p := (*[_MaxMem/2/2 - 1]uint16)(unsafe.Pointer(s))
+ p := (*[maxAlloc/2/2 - 1]uint16)(unsafe.Pointer(s))
l := 0
for p[l] != 0 {
l++
return l
}
-var maxstring uintptr = 256 // a hint for print
-
//go:nosplit
func gostringnocopy(str *byte) string {
ss := stringStruct{str: unsafe.Pointer(str), len: findnull(str)}
s := *(*string)(unsafe.Pointer(&ss))
- for {
- ms := maxstring
- if uintptr(len(s)) <= ms || atomic.Casuintptr(&maxstring, ms, uintptr(len(s))) {
- break
- }
- }
return s
}
func gostringw(strw *uint16) string {
var buf [8]byte
- str := (*[_MaxMem/2/2 - 1]uint16)(unsafe.Pointer(strw))
+ str := (*[maxAlloc/2/2 - 1]uint16)(unsafe.Pointer(strw))
n1 := 0
for i := 0; str[i] != 0; i++ {
- n1 += runetochar(buf[:], rune(str[i]))
+ n1 += encoderune(buf[:], rune(str[i]))
}
s, b := rawstring(n1 + 4)
n2 := 0
if n2 >= n1 {
break
}
- n2 += runetochar(b[n2:], rune(str[i]))
+ n2 += encoderune(b[n2:], rune(str[i]))
}
b[n2] = 0 // for luck
return s[:n2]