github.com/huandu/go@v0.0.0-20151114150818-04e615e41150/misc/cgo/testcshared/src/libgo2/libgo2.go (about)

     1  // Copyright 2015 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 darwin dragonfly freebsd linux netbsd openbsd solaris
     6  
     7  package main
     8  
     9  // Test a shared library created by -buildmode=c-shared that does not
    10  // export anything.
    11  
    12  import (
    13  	"fmt"
    14  	"os"
    15  	"syscall"
    16  )
    17  
    18  // To test this we want to communicate between the main program and
    19  // the shared library without using any exported symbols.  The init
    20  // function creates a pipe and Dups the read end to a known number
    21  // that the C code can also use.
    22  
    23  const (
    24  	fd = 10
    25  )
    26  
    27  func init() {
    28  	var p [2]int
    29  	if e := syscall.Pipe(p[0:]); e != nil {
    30  		fmt.Fprintf(os.Stderr, "pipe: %v\n", e)
    31  		os.Exit(2)
    32  	}
    33  
    34  	if e := syscall.Dup2(p[0], fd); e != nil {
    35  		fmt.Fprintf(os.Stderr, "dup2: %v\n", e)
    36  		os.Exit(2)
    37  	}
    38  
    39  	const str = "PASS"
    40  	if n, e := syscall.Write(p[1], []byte(str)); e != nil || n != len(str) {
    41  		fmt.Fprintf(os.Stderr, "write: %d %v\n", n, e)
    42  		os.Exit(2)
    43  	}
    44  
    45  	if e := syscall.Close(p[1]); e != nil {
    46  		fmt.Fprintf(os.Stderr, "close: %v\n", e)
    47  		os.Exit(2)
    48  	}
    49  }
    50  
    51  func main() {
    52  }