github.com/riscv/riscv-go@v0.0.0-20200123204226-124ebd6fcc8e/misc/cgo/test/issue3729.go (about)

     1  // Copyright 2012 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  // Issue 3729:	cmd/cgo: access errno from void C function
     6  // void f(void) returns [0]byte, error in Go world.
     7  
     8  // +build !windows
     9  
    10  package cgotest
    11  
    12  /*
    13  #include <errno.h>
    14  
    15  void g(void) {
    16  	errno = E2BIG;
    17  }
    18  
    19  // try to pass some non-trivial arguments to function g2
    20  const char _expA = 0x42;
    21  const float _expB = 3.14159;
    22  const short _expC = 0x55aa;
    23  const int _expD = 0xdeadbeef;
    24  void g2(int x, char a, float b, short c, int d) {
    25  	if (a == _expA && b == _expB && c == _expC && d == _expD)
    26  		errno = x;
    27  	else
    28  		errno = -1;
    29  }
    30  */
    31  import "C"
    32  
    33  import (
    34  	"syscall"
    35  	"testing"
    36  )
    37  
    38  func test3729(t *testing.T) {
    39  	_, e := C.g()
    40  	if e != syscall.E2BIG {
    41  		t.Errorf("got %q, expect %q", e, syscall.E2BIG)
    42  	}
    43  	_, e = C.g2(C.EINVAL, C._expA, C._expB, C._expC, C._expD)
    44  	if e != syscall.EINVAL {
    45  		t.Errorf("got %q, expect %q", e, syscall.EINVAL)
    46  	}
    47  }