package main
import "time"
func main() {
s := []int{100, 200}
println(&s)
go func() {
s[0] = 300
s = []int{300, 400}
}()
time.Sleep(1 * time.Second)
}
just curious about this ,can you help explain the assemble code here
"".main t=1 size=241 args=0x0 locals=0x28
0x0000 00000 (main.go:5) TEXT "".main(SB), $40-0
0x0000 00000 (main.go:5) MOVQ (TLS), CX
0x0009 00009 (main.go:5) CMPQ SP, 16(CX)
0x000d 00013 (main.go:5) JLS 231
0x0013 00019 (main.go:5) SUBQ $40, SP
0x0017 00023 (main.go:5) MOVQ BP, 32(SP)
0x001c 00028 (main.go:5) LEAQ 32(SP), BP
0x0021 00033 (main.go:5) FUNCDATA $0,
gclocals·69c1753bd5f81501d95132d08af04464(SB)
0x0021 00033 (main.go:5) FUNCDATA $1,
gclocals·0c8aa8e80191a30eac23f1a218103f16(SB)
0x0021 00033 (main.go:6) LEAQ type.[]int(SB), AX
0x0028 00040 (main.go:6) MOVQ AX, (SP)
0x002c 00044 (main.go:6) PCDATA $0, $0
0x002c 00044 (main.go:6) CALL runtime.newobject(SB)
0x0031 00049 (main.go:6) MOVQ 8(SP), AX
0x0036 00054 (main.go:6) MOVQ AX, "".&s+24(SP)
0x003b 00059 (main.go:6) LEAQ type.[2]int(SB), CX
0x0042 00066 (main.go:6) MOVQ CX, (SP)
0x0046 00070 (main.go:6) PCDATA $0, $1
0x0046 00070 (main.go:6) CALL runtime.newobject(SB)
0x004b 00075 (main.go:6) MOVQ 8(SP), AX
0x0050 00080 (main.go:6) MOVUPS "".statictmp_2(SB), X0
0x0057 00087 (main.go:6) MOVUPS X0, (AX)
0x005a 00090 (main.go:6) MOVQ "".&s+24(SP), CX
0x005f 00095 (main.go:6) MOVQ $2, 8(CX)
0x0067 00103 (main.go:6) MOVQ $2, 16(CX)
0x006f 00111 (main.go:6) MOVL runtime.writeBarrier(SB), DX
0x0075 00117 (main.go:6) TESTB DL, DL
0x0077 00119 (main.go:6) JNE $0, 210
0x0079 00121 (main.go:6) MOVQ AX, (CX)
0x007c 00124 (main.go:7) PCDATA $0, $1
0x007c 00124 (main.go:7) CALL runtime.printlock(SB)
0x0081 00129 (main.go:7) MOVQ "".&s+24(SP), AX
0x0086 00134 (main.go:7) MOVQ AX, (SP)
0x008a 00138 (main.go:7) PCDATA $0, $1
0x008a 00138 (main.go:7) CALL runtime.printpointer(SB)
0x008f 00143 (main.go:7) PCDATA $0, $1
0x008f 00143 (main.go:7) CALL runtime.printnl(SB)
0x0094 00148 (main.go:7) PCDATA $0, $1
0x0094 00148 (main.go:7) CALL runtime.printunlock(SB)
0x0099 00153 (main.go:11) MOVQ "".&s+24(SP), AX
0x009e 00158 (main.go:11) MOVQ AX, 16(SP)
0x00a3 00163 (main.go:11) MOVL $8, (SP)
0x00aa 00170 (main.go:11) LEAQ "".main.func1·f(SB), AX
0x00b1 00177 (main.go:11) MOVQ AX, 8(SP)
0x00b6 00182 (main.go:11) PCDATA $0, $0
0x00b6 00182 (main.go:11) CALL runtime.newproc(SB)
0x00bb 00187 (main.go:12) MOVQ $1000000000, (SP)
0x00c3 00195 (main.go:12) PCDATA $0, $0
0x00c3 00195 (main.go:12) CALL time.Sleep(SB)
0x00c8 00200 (main.go:13) MOVQ 32(SP), BP
0x00cd 00205 (main.go:13) ADDQ $40, SP
0x00d1 00209 (main.go:13) RET
0x00d2 00210 (main.go:6) MOVQ CX, (SP)
0x00d6 00214 (main.go:6) MOVQ AX, 8(SP)
0x00db 00219 (main.go:6) PCDATA $0, $1
0x00db 00219 (main.go:6) CALL runtime.writebarrierptr(SB)
0x00e0 00224 (main.go:6) MOVQ "".&s+24(SP), CX
0x00e5 00229 (main.go:7) JMP 124
0x00e7 00231 (main.go:7) NOP
0x00e7 00231 (main.go:5) CALL runtime.morestack_noctxt(SB)
0x00ec 00236 (main.go:5) JMP 0
在 2016年11月3日星期四 UTC+8下午2:56:10，Ian Lance Taylor写道：
>
> On Wed, Nov 2, 2016 at 11:48 PM, 刘桂祥 <liuguix...@gmail.com <javascript:>>
> wrote:
> > I just want to look what variable datastructure is passed to the closure
> > func but I am confused with the assemble code
> >
> >
> > // example.go
> >
> > package main
> >
> >
> > import "time"
> >
> >
> > func main() {
> >
> > s := []int{100, 200}
> >
> > func() {
> >
> > s[0] = 300
> >
> > s = []int{300, 400}
> >
> > }()
> >
> > time.Sleep(1 * time.Second)
> >
> > }
>
> In this example you are calling the function directly, so the compiler
> doesn't use a closure at all. It simply passes the closure values as
> arguments to the function. There is no need for an actual closure
> when you always call the function.
>
> Ian
>
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