github.com/zhongdalu/gf@v1.0.0/third/golang.org/x/sys/unix/mkasm_darwin.go (about)

     1  // Copyright 2018 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // +build ignore
     6  
     7  // mkasm_darwin.go generates assembly trampolines to call libSystem routines from Go.
     8  //This program must be run after mksyscall.go.
     9  package main
    10  
    11  import (
    12  	"bytes"
    13  	"fmt"
    14  	"io/ioutil"
    15  	"log"
    16  	"os"
    17  	"strings"
    18  )
    19  
    20  func main() {
    21  	in1, err := ioutil.ReadFile("syscall_darwin.go")
    22  	if err != nil {
    23  		log.Fatalf("can't open syscall_darwin.go: %s", err)
    24  	}
    25  	arch := os.Args[1]
    26  	in2, err := ioutil.ReadFile(fmt.Sprintf("syscall_darwin_%s.go", arch))
    27  	if err != nil {
    28  		log.Fatalf("can't open syscall_darwin_%s.go: %s", arch, err)
    29  	}
    30  	in3, err := ioutil.ReadFile(fmt.Sprintf("zsyscall_darwin_%s.go", arch))
    31  	if err != nil {
    32  		log.Fatalf("can't open zsyscall_darwin_%s.go: %s", arch, err)
    33  	}
    34  	in := string(in1) + string(in2) + string(in3)
    35  
    36  	trampolines := map[string]bool{}
    37  
    38  	var out bytes.Buffer
    39  
    40  	fmt.Fprintf(&out, "// go run mkasm_darwin.go %s\n", strings.Join(os.Args[1:], " "))
    41  	fmt.Fprintf(&out, "// Code generated by the command above; DO NOT EDIT.\n")
    42  	fmt.Fprintf(&out, "\n")
    43  	fmt.Fprintf(&out, "// +build go1.12\n")
    44  	fmt.Fprintf(&out, "\n")
    45  	fmt.Fprintf(&out, "#include \"textflag.h\"\n")
    46  	for _, line := range strings.Split(in, "\n") {
    47  		if !strings.HasPrefix(line, "func ") || !strings.HasSuffix(line, "_trampoline()") {
    48  			continue
    49  		}
    50  		fn := line[5 : len(line)-13]
    51  		if !trampolines[fn] {
    52  			trampolines[fn] = true
    53  			fmt.Fprintf(&out, "TEXT ยท%s_trampoline(SB),NOSPLIT,$0-0\n", fn)
    54  			fmt.Fprintf(&out, "\tJMP\t%s(SB)\n", fn)
    55  		}
    56  	}
    57  	err = ioutil.WriteFile(fmt.Sprintf("zsyscall_darwin_%s.s", arch), out.Bytes(), 0644)
    58  	if err != nil {
    59  		log.Fatalf("can't write zsyscall_darwin_%s.s: %s", arch, err)
    60  	}
    61  }