代码：
package main
import "fmt"
func test(x, y int) func() {
return func() {
x += y
}
}
func main() {
f := test(0x100, 0x200)
f()
fmt.Println("close")
}
编译：
go build -gcflags "-N -l" -o test main.go
GDB：
info "(gdb)Auto-loading safe path"
(gdb) l
2
3 import "fmt"
4
5 func test(x, y int) func() {
6 return func() {
7 x += y
8 }
9 }
10
11 func main() {
(gdb) l
12 f := test(0x100, 0x200)
13 f()
14 fmt.Println("close")
15 }
(gdb) b 13
Breakpoint 1 at 0x483291: file /home/devops/study/src/function/closed_function.go, line 13.
(gdb) b 6
Breakpoint 2 at 0x4831cc: /home/devops/study/src/function/closed_function.go:6. (2 locations)
(gdb) r
Starting program: /home/devops/study/src/function/test
Breakpoint 2, main.test (x=256, y=512, ~r2={void ()} 0xc420043f20) at /home/devops/study/src/function/closed_function.go:6
6 return func() {
(gdb) set disassembly-flavor intel
(gdb) disassemble
Dump of assembler code for function main.test:
0x0000000000483180 : mov rcx,QWORD PTR fs:0xfffffffffffffff8
0x0000000000483189 : cmp rsp,QWORD PTR [rcx+0x10]
0x000000000048318d : jbe 0x483240
0x0000000000483193 : sub rsp,0x28
0x0000000000483197 : mov QWORD PTR [rsp+0x20],rbp
0x000000000048319c : lea rbp,[rsp+0x20]
0x00000000004831a1 : mov QWORD PTR [rsp+0x40],0x0
0x00000000004831aa : lea rax,[rip+0x103af] # 0x493560
0x00000000004831b1 : mov QWORD PTR [rsp],rax
0x00000000004831b5 : call 0x40e3c0
0x00000000004831ba : mov rax,QWORD PTR [rsp+0x8]
0x00000000004831bf : mov QWORD PTR [rsp+0x18],rax
0x00000000004831c4 : mov rcx,QWORD PTR [rsp+0x30]
0x00000000004831c9 : mov QWORD PTR [rax],rcx
=> 0x00000000004831cc : lea rax,[rip+0x1e44d] # 0x4a1620
0x00000000004831d3 : mov QWORD PTR [rsp],rax
0x00000000004831d7 : call 0x40e3c0 # this wihle return a unsafe.Poniter
0x00000000004831dc : mov rax,QWORD PTR [rsp+0x8]
0x00000000004831e1 : mov QWORD PTR [rsp+0x10],rax
0x00000000004831e6 : lea rcx,[rip+0x133] # 0x483320
0x00000000004831ed : mov QWORD PTR [rax],rcx
0x00000000004831f0 : mov rax,QWORD PTR [rsp+0x10]
0x00000000004831f5 : test BYTE PTR [rax],al
0x00000000004831f7 : mov ecx,DWORD PTR [rip+0xc2de3] # 0x545fe0
0x00000000004831fd : mov rdx,QWORD PTR [rsp+0x18]
0x0000000000483202 : lea rdi,[rax+0x8]
0x0000000000483206 : test ecx,ecx
0x0000000000483208 : jne 0x483236
0x000000000048320a : jmp 0x48320c
0x000000000048320c : mov QWORD PTR [rax+0x8],rdx
0x0000000000483210 : jmp 0x483212
0x0000000000483212 : mov rax,QWORD PTR [rsp+0x10]
0x0000000000483217 : test BYTE PTR [rax],al
0x0000000000483219 : mov rcx,QWORD PTR [rsp+0x38]
0x000000000048321e : mov QWORD PTR [rax+0x10],rcx
0x0000000000483222 : mov rax,QWORD PTR [rsp+0x10]
0x0000000000483227 : mov QWORD PTR [rsp+0x40],rax
0x000000000048322c : mov rbp,QWORD PTR [rsp+0x20]
0x0000000000483231 : add rsp,0x28
0x0000000000483235 : ret
0x0000000000483236 : mov rax,rdx
0x0000000000483239 : call 0x44f5c0
0x000000000048323e : jmp 0x483212
0x0000000000483240 : call 0x44d170
0x0000000000483245 : jmp 0x483180
End of assembler dump.
(gdb) c
Continuing.
Breakpoint 1, main.main () at /home/devops/study/src/function/closed_function.go:13
13
(gdb) x/16xg $rsp
0xc420043f10: 0x0000000000000100 0x0000000000000200
0xc420043f20: 0x000000c42000a060 0x000000000040423c
0xc420043f30: 0x000000c42005a058 0x0000000000000000
0xc420043f40: 0x000000c42000a060 0x00000000004b7465
0xc420043f50: 0x0000000000000000 0x0000000000000000
0xc420043f60: 0x000000c42000e1d0 0x000000c420043f78
0xc420043f70: 0x000000c42005a058 0x000000c420043f80
0xc420043f80: 0x0000000000427f32 0x000000c42005a000
(gdb) x/3xg 0x000000c42000a060
0xc42000a060: 0x0000000000483320 0x000000c420014098
0xc42000a070: 0x0000000000000200
(gdb) x/1xg 0x000000c420014098
0xc420014098: 0x0000000000000100
通过查看变量的内存地址，找到最终的相应变量，并且内存地址不在堆上，而是运行时。 newobject只分配一个似乎跟随的指针，并且不会继续指向该操作？