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path: root/libgo/go/runtime/string.go
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Diffstat (limited to 'libgo/go/runtime/string.go')
-rw-r--r--libgo/go/runtime/string.go58
1 files changed, 31 insertions, 27 deletions
diff --git a/libgo/go/runtime/string.go b/libgo/go/runtime/string.go
index df4cae7..c0058be 100644
--- a/libgo/go/runtime/string.go
+++ b/libgo/go/runtime/string.go
@@ -6,6 +6,7 @@ package runtime
import (
"internal/bytealg"
+ "runtime/internal/sys"
"unsafe"
)
@@ -70,47 +71,54 @@ func concatstrings(buf *tmpBuf, p *string, n int) string {
return s
}
+// 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) (str string) {
- l := len(b)
- if l == 0 {
+func slicebytetostring(buf *tmpBuf, ptr *byte, n int) (str 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 {
- racereadrangepc(unsafe.Pointer(&b[0]),
- uintptr(l),
+ racereadrangepc(unsafe.Pointer(ptr),
+ uintptr(n),
getcallerpc(),
funcPC(slicebytetostring))
}
if msanenabled {
- msanread(unsafe.Pointer(&b[0]), uintptr(l))
+ msanread(unsafe.Pointer(ptr), uintptr(n))
}
- if l == 1 {
- stringStructOf(&str).str = unsafe.Pointer(&staticbytes[b[0]])
+ if n == 1 {
+ p := unsafe.Pointer(&staticuint64s[*ptr])
+ if sys.BigEndian {
+ p = add(p, 7)
+ }
+ stringStructOf(&str).str = p
stringStructOf(&str).len = 1
return
}
var p unsafe.Pointer
- if buf != nil && len(b) <= len(buf) {
+ if buf != nil && n <= len(buf) {
p = unsafe.Pointer(buf)
} else {
- p = mallocgc(uintptr(len(b)), nil, false)
+ p = mallocgc(uintptr(n), nil, false)
}
stringStructOf(&str).str = p
- stringStructOf(&str).len = len(b)
- memmove(p, (*(*slice)(unsafe.Pointer(&b))).array, uintptr(len(b)))
+ stringStructOf(&str).len = n
+ memmove(p, unsafe.Pointer(ptr), uintptr(n))
return
}
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)
}
@@ -131,17 +139,19 @@ func rawstringtmp(buf *tmpBuf, l int) (s string, b []byte) {
// 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(b []byte) string {
- if raceenabled && len(b) > 0 {
- racereadrangepc(unsafe.Pointer(&b[0]),
- uintptr(len(b)),
+func slicebytetostringtmp(ptr *byte, n int) (str string) {
+ if raceenabled && n > 0 {
+ racereadrangepc(unsafe.Pointer(ptr),
+ uintptr(n),
getcallerpc(),
funcPC(slicebytetostringtmp))
}
- if msanenabled && len(b) > 0 {
- msanread(unsafe.Pointer(&b[0]), uintptr(len(b)))
+ if msanenabled && n > 0 {
+ msanread(unsafe.Pointer(ptr), uintptr(n))
}
- return *(*string)(unsafe.Pointer(&b))
+ stringStructOf(&str).str = unsafe.Pointer(ptr)
+ stringStructOf(&str).len = n
+ return
}
func stringtoslicebyte(buf *tmpBuf, s string) []byte {
@@ -223,16 +233,10 @@ func stringStructOf(sp *string) *stringStruct {
}
func intstring(buf *[4]byte, v int64) (s string) {
- if v >= 0 && v < runeSelf {
- stringStructOf(&s).str = unsafe.Pointer(&staticbytes[v])
- stringStructOf(&s).len = 1
- return
- }
-
var b []byte
if buf != nil {
b = buf[:]
- s = slicebytetostringtmp(b)
+ s = slicebytetostringtmp(&b[0], len(b))
} else {
s, b = rawstring(4)
}