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// Copyright 2009 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"
// The compiler knows that a print of a value of this type
// should use printhex instead of printuint (decimal).
type hex uint64
func bytes(s string) (ret []byte) {
rp := (*slice)(unsafe.Pointer(&ret))
sp := stringStructOf(&s)
rp.array = sp.str
rp.len = sp.len
rp.cap = sp.len
return
}
var debuglock mutex
// The compiler emits calls to printlock and printunlock around
// the multiple calls that implement a single Go print or println
// statement. Some of the print helpers (printsp, for example)
// call print recursively. There is also the problem of a crash
// happening during the print routines and needing to acquire
// the print lock to print information about the crash.
// For both these reasons, let a thread acquire the printlock 'recursively'.
func printlock() {
mp := getg().m
mp.locks++ // do not reschedule between printlock++ and lock(&debuglock).
mp.printlock++
if mp.printlock == 1 {
lock(&debuglock)
}
mp.locks-- // now we know debuglock is held and holding up mp.locks for us.
}
func printunlock() {
mp := getg().m
mp.printlock--
if mp.printlock == 0 {
unlock(&debuglock)
}
}
// write to goroutine-local buffer if diverting output,
// or else standard error.
func gwrite(b []byte) {
if len(b) == 0 {
return
}
gp := getg()
if gp == nil || gp.writebuf == nil {
writeErr(b)
return
}
n := copy(gp.writebuf[len(gp.writebuf):cap(gp.writebuf)], b)
gp.writebuf = gp.writebuf[:len(gp.writebuf)+n]
}
func printsp() {
print(" ")
}
func printnl() {
print("\n")
}
func printbool(v bool) {
if v {
print("true")
} else {
print("false")
}
}
func printfloat(v float64) {
switch {
case v != v:
print("NaN")
return
case v+v == v && v > 0:
print("+Inf")
return
case v+v == v && v < 0:
print("-Inf")
return
}
const n = 7 // digits printed
var buf [n + 7]byte
buf[0] = '+'
e := 0 // exp
if v == 0 {
if 1/v < 0 {
buf[0] = '-'
}
} else {
if v < 0 {
v = -v
buf[0] = '-'
}
// normalize
for v >= 10 {
e++
v /= 10
}
for v < 1 {
e--
v *= 10
}
// round
h := 5.0
for i := 0; i < n; i++ {
h /= 10
}
v += h
if v >= 10 {
e++
v /= 10
}
}
// format +d.dddd+edd
for i := 0; i < n; i++ {
s := int(v)
buf[i+2] = byte(s + '0')
v -= float64(s)
v *= 10
}
buf[1] = buf[2]
buf[2] = '.'
buf[n+2] = 'e'
buf[n+3] = '+'
if e < 0 {
e = -e
buf[n+3] = '-'
}
buf[n+4] = byte(e/100) + '0'
buf[n+5] = byte(e/10)%10 + '0'
buf[n+6] = byte(e%10) + '0'
gwrite(buf[:])
}
func printcomplex(c complex128) {
print("(", real(c), imag(c), "i)")
}
func printuint(v uint64) {
var buf [100]byte
i := len(buf)
for i--; i > 0; i-- {
buf[i] = byte(v%10 + '0')
if v < 10 {
break
}
v /= 10
}
gwrite(buf[i:])
}
func printint(v int64) {
if v < 0 {
print("-")
v = -v
}
printuint(uint64(v))
}
func printhex(v uint64) {
const dig = "0123456789abcdef"
var buf [100]byte
i := len(buf)
for i--; i > 0; i-- {
buf[i] = dig[v%16]
if v < 16 {
break
}
v /= 16
}
i--
buf[i] = 'x'
i--
buf[i] = '0'
gwrite(buf[i:])
}
func printpointer(p unsafe.Pointer) {
printhex(uint64(uintptr(p)))
}
func printstring(s string) {
if uintptr(len(s)) > maxstring {
gwrite(bytes("[string too long]"))
return
}
gwrite(bytes(s))
}
func printslice(s []byte) {
sp := (*slice)(unsafe.Pointer(&s))
print("[", len(s), "/", cap(s), "]")
printpointer(unsafe.Pointer(sp.array))
}
func printeface(e eface) {
print("(", e._type, ",", e.data, ")")
}
func printiface(i iface) {
print("(", i.tab, ",", i.data, ")")
}
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