mirror of git://gcc.gnu.org/git/gcc.git
447 lines
10 KiB
Go
447 lines
10 KiB
Go
// Copyright 2014 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package runtime
|
|
|
|
import (
|
|
"unsafe"
|
|
)
|
|
|
|
// For gccgo, use go:linkname to rename compiler-called functions to
|
|
// themselves, so that the compiler will export them.
|
|
//
|
|
//go:linkname concatstrings runtime.concatstrings
|
|
//go:linkname concatstring2 runtime.concatstring2
|
|
//go:linkname concatstring3 runtime.concatstring3
|
|
//go:linkname concatstring4 runtime.concatstring4
|
|
//go:linkname concatstring5 runtime.concatstring5
|
|
//go:linkname slicebytetostring runtime.slicebytetostring
|
|
//go:linkname slicebytetostringtmp runtime.slicebytetostringtmp
|
|
//go:linkname stringtoslicebyte runtime.stringtoslicebyte
|
|
//go:linkname stringtoslicebytetmp runtime.stringtoslicebytetmp
|
|
//go:linkname stringtoslicerune runtime.stringtoslicerune
|
|
//go:linkname slicerunetostring runtime.slicerunetostring
|
|
//go:linkname intstring runtime.intstring
|
|
//go:linkname stringiter runtime.stringiter
|
|
//go:linkname stringiter2 runtime.stringiter2
|
|
// Temporary for C code to call:
|
|
//go:linkname gostringnocopy runtime.gostringnocopy
|
|
//go:linkname findnull runtime.findnull
|
|
|
|
// The constant is known to the compiler.
|
|
// There is no fundamental theory behind this number.
|
|
const tmpStringBufSize = 32
|
|
|
|
type tmpBuf [tmpStringBufSize]byte
|
|
|
|
// concatstrings implements a Go string concatenation x+y+z+...
|
|
// The operands are passed in the slice a.
|
|
// If buf != nil, the compiler has determined that the result does not
|
|
// escape the calling function, so the string data can be stored in buf
|
|
// if small enough.
|
|
func concatstrings(buf *tmpBuf, a []string) string {
|
|
// idx := 0
|
|
l := 0
|
|
count := 0
|
|
for _, x := range a {
|
|
n := len(x)
|
|
if n == 0 {
|
|
continue
|
|
}
|
|
if l+n < l {
|
|
throw("string concatenation too long")
|
|
}
|
|
l += n
|
|
count++
|
|
// idx = i
|
|
}
|
|
if count == 0 {
|
|
return ""
|
|
}
|
|
|
|
// If there is just one string and either it is not on the stack
|
|
// or our result does not escape the calling frame (buf != nil),
|
|
// then we can return that string directly.
|
|
// Commented out for gccgo--no implementation of stringDataOnStack.
|
|
// if count == 1 && (buf != nil || !stringDataOnStack(a[idx])) {
|
|
// return a[idx]
|
|
// }
|
|
s, b := rawstringtmp(buf, l)
|
|
l = 0
|
|
for _, x := range a {
|
|
copy(b[l:], x)
|
|
l += len(x)
|
|
}
|
|
return s
|
|
}
|
|
|
|
func concatstring2(buf *tmpBuf, a [2]string) string {
|
|
return concatstrings(buf, a[:])
|
|
}
|
|
|
|
func concatstring3(buf *tmpBuf, a [3]string) string {
|
|
return concatstrings(buf, a[:])
|
|
}
|
|
|
|
func concatstring4(buf *tmpBuf, a [4]string) string {
|
|
return concatstrings(buf, a[:])
|
|
}
|
|
|
|
func concatstring5(buf *tmpBuf, a [5]string) string {
|
|
return concatstrings(buf, a[:])
|
|
}
|
|
|
|
// 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 {
|
|
// 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 msanenabled && l > 0 {
|
|
msanread(unsafe.Pointer(&b[0]), uintptr(l))
|
|
}
|
|
s, c := rawstringtmp(buf, l)
|
|
copy(c, b)
|
|
return s
|
|
}
|
|
|
|
func rawstringtmp(buf *tmpBuf, l int) (s string, b []byte) {
|
|
if buf != nil && l <= len(buf) {
|
|
b = buf[:l]
|
|
s = slicebytetostringtmp(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))
|
|
}
|
|
|
|
func stringtoslicebyte(buf *tmpBuf, s string) []byte {
|
|
var b []byte
|
|
if buf != nil && len(s) <= len(buf) {
|
|
*buf = tmpBuf{}
|
|
b = buf[:len(s)]
|
|
} else {
|
|
b = rawbyteslice(len(s))
|
|
}
|
|
copy(b, 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: 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:]
|
|
n++
|
|
}
|
|
var a []rune
|
|
if buf != nil && n <= len(buf) {
|
|
*buf = [tmpStringBufSize]rune{}
|
|
a = buf[:n]
|
|
} else {
|
|
a = rawruneslice(n)
|
|
}
|
|
n = 0
|
|
for len(t) > 0 {
|
|
r, k := charntorune(t)
|
|
t = t[k:]
|
|
a[n] = r
|
|
n++
|
|
}
|
|
return a
|
|
}
|
|
|
|
func slicerunetostring(buf *tmpBuf, a []rune) string {
|
|
if raceenabled && len(a) > 0 {
|
|
racereadrangepc(unsafe.Pointer(&a[0]),
|
|
uintptr(len(a))*unsafe.Sizeof(a[0]),
|
|
getcallerpc(unsafe.Pointer(&buf)),
|
|
funcPC(slicerunetostring))
|
|
}
|
|
if msanenabled && len(a) > 0 {
|
|
msanread(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)
|
|
}
|
|
s, b := rawstringtmp(buf, size1+3)
|
|
size2 := 0
|
|
for _, r := range a {
|
|
// check for race
|
|
if size2 >= size1 {
|
|
break
|
|
}
|
|
size2 += runetochar(b[size2:], r)
|
|
}
|
|
return s[:size2]
|
|
}
|
|
|
|
type stringStruct struct {
|
|
str unsafe.Pointer
|
|
len int
|
|
}
|
|
|
|
// Variant with *byte pointer type for DWARF debugging.
|
|
type stringStructDWARF struct {
|
|
str *byte
|
|
len int
|
|
}
|
|
|
|
func stringStructOf(sp *string) *stringStruct {
|
|
return (*stringStruct)(unsafe.Pointer(sp))
|
|
}
|
|
|
|
func intstring(buf *[4]byte, v int64) string {
|
|
var s string
|
|
var b []byte
|
|
if buf != nil {
|
|
b = buf[:]
|
|
s = slicebytetostringtmp(b)
|
|
} else {
|
|
s, b = rawstring(4)
|
|
}
|
|
if int64(rune(v)) != v {
|
|
v = runeerror
|
|
}
|
|
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
|
|
}
|
|
|
|
// 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
|
|
}
|
|
|
|
// rawstring allocates storage for a new string. The returned
|
|
// string and byte slice both refer to the same storage.
|
|
// 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, false)
|
|
|
|
stringStructOf(&s).str = p
|
|
stringStructOf(&s).len = size
|
|
|
|
*(*slice)(unsafe.Pointer(&b)) = slice{p, size, size}
|
|
return
|
|
}
|
|
|
|
// 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, false)
|
|
if cap != uintptr(size) {
|
|
memclr(add(p, uintptr(size)), cap-uintptr(size))
|
|
}
|
|
|
|
*(*slice)(unsafe.Pointer(&b)) = slice{p, size, int(cap)}
|
|
return
|
|
}
|
|
|
|
// rawruneslice allocates a new rune slice. The rune slice is not zeroed.
|
|
func rawruneslice(size int) (b []rune) {
|
|
if uintptr(size) > _MaxMem/4 {
|
|
throw("out of memory")
|
|
}
|
|
mem := roundupsize(uintptr(size) * 4)
|
|
p := mallocgc(mem, nil, false)
|
|
if mem != uintptr(size)*4 {
|
|
memclr(add(p, uintptr(size)*4), mem-uintptr(size)*4)
|
|
}
|
|
|
|
*(*slice)(unsafe.Pointer(&b)) = slice{p, size, int(mem / 4)}
|
|
return
|
|
}
|
|
|
|
// used by cmd/cgo
|
|
func gobytes(p *byte, n int) []byte {
|
|
if n == 0 {
|
|
return make([]byte, 0)
|
|
}
|
|
x := make([]byte, n)
|
|
memmove(unsafe.Pointer(&x[0]), unsafe.Pointer(p), uintptr(n))
|
|
return x
|
|
}
|
|
|
|
func gostring(p *byte) string {
|
|
l := findnull(p)
|
|
if l == 0 {
|
|
return ""
|
|
}
|
|
s, b := rawstring(l)
|
|
memmove(unsafe.Pointer(&b[0]), unsafe.Pointer(p), uintptr(l))
|
|
return s
|
|
}
|
|
|
|
func gostringn(p *byte, l int) string {
|
|
if l == 0 {
|
|
return ""
|
|
}
|
|
s, b := rawstring(l)
|
|
memmove(unsafe.Pointer(&b[0]), unsafe.Pointer(p), uintptr(l))
|
|
return s
|
|
}
|
|
|
|
func index(s, t string) int {
|
|
if len(t) == 0 {
|
|
return 0
|
|
}
|
|
for i := 0; i < len(s); i++ {
|
|
if s[i] == t[0] && hasprefix(s[i:], t) {
|
|
return i
|
|
}
|
|
}
|
|
return -1
|
|
}
|
|
|
|
func contains(s, t string) bool {
|
|
return index(s, t) >= 0
|
|
}
|
|
|
|
func hasprefix(s, t string) bool {
|
|
return len(s) >= len(t) && s[:len(t)] == t
|
|
}
|
|
|
|
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:]
|
|
}
|
|
return n
|
|
}
|
|
|
|
//go:nosplit
|
|
func findnull(s *byte) int {
|
|
if s == nil {
|
|
return 0
|
|
}
|
|
p := (*[_MaxMem/2 - 1]byte)(unsafe.Pointer(s))
|
|
l := 0
|
|
for p[l] != 0 {
|
|
l++
|
|
}
|
|
return l
|
|
}
|
|
|
|
func findnullw(s *uint16) int {
|
|
if s == nil {
|
|
return 0
|
|
}
|
|
p := (*[_MaxMem/2/2 - 1]uint16)(unsafe.Pointer(s))
|
|
l := 0
|
|
for p[l] != 0 {
|
|
l++
|
|
}
|
|
return l
|
|
}
|
|
|
|
//go:nosplit
|
|
func gostringnocopy(str *byte) string {
|
|
ss := stringStruct{str: unsafe.Pointer(str), len: findnull(str)}
|
|
s := *(*string)(unsafe.Pointer(&ss))
|
|
return s
|
|
}
|
|
|
|
func gostringw(strw *uint16) string {
|
|
var buf [8]byte
|
|
str := (*[_MaxMem/2/2 - 1]uint16)(unsafe.Pointer(strw))
|
|
n1 := 0
|
|
for i := 0; str[i] != 0; i++ {
|
|
n1 += runetochar(buf[:], rune(str[i]))
|
|
}
|
|
s, b := rawstring(n1 + 4)
|
|
n2 := 0
|
|
for i := 0; str[i] != 0; i++ {
|
|
// check for race
|
|
if n2 >= n1 {
|
|
break
|
|
}
|
|
n2 += runetochar(b[n2:], rune(str[i]))
|
|
}
|
|
b[n2] = 0 // for luck
|
|
return s[:n2]
|
|
}
|