github.com/peggyl/go@v0.0.0-20151008231540-ae315999c2d5/misc/cgo/test/issue10303.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  // Issue 10303. Pointers passed to C were not marked as escaping (bug in cgo).
     6  
     7  package cgotest
     8  
     9  /*
    10  typedef int *intptr;
    11  
    12  void setintstar(int *x) {
    13  	*x = 1;
    14  }
    15  
    16  void setintptr(intptr x) {
    17  	*x = 1;
    18  }
    19  
    20  void setvoidptr(void *x) {
    21  	*(int*)x = 1;
    22  }
    23  
    24  typedef struct Struct Struct;
    25  struct Struct {
    26  	int *P;
    27  };
    28  
    29  void setstruct(Struct s) {
    30  	*s.P = 1;
    31  }
    32  
    33  */
    34  import "C"
    35  
    36  import (
    37  	"testing"
    38  	"unsafe"
    39  )
    40  
    41  func test10303(t *testing.T, n int) {
    42  	// Run at a few different stack depths just to avoid an unlucky pass
    43  	// due to variables ending up on different pages.
    44  	if n > 0 {
    45  		test10303(t, n-1)
    46  	}
    47  	if t.Failed() {
    48  		return
    49  	}
    50  	var x, y, z, v, si C.int
    51  	var s C.Struct
    52  	C.setintstar(&x)
    53  	C.setintptr(&y)
    54  	C.setvoidptr(unsafe.Pointer(&v))
    55  	s.P = &si
    56  	C.setstruct(s)
    57  
    58  	if uintptr(unsafe.Pointer(&x))&^0xfff == uintptr(unsafe.Pointer(&z))&^0xfff {
    59  		t.Error("C int* argument on stack")
    60  	}
    61  	if uintptr(unsafe.Pointer(&y))&^0xfff == uintptr(unsafe.Pointer(&z))&^0xfff {
    62  		t.Error("C intptr argument on stack")
    63  	}
    64  	if uintptr(unsafe.Pointer(&v))&^0xfff == uintptr(unsafe.Pointer(&z))&^0xfff {
    65  		t.Error("C void* argument on stack")
    66  	}
    67  	if uintptr(unsafe.Pointer(&si))&^0xfff == uintptr(unsafe.Pointer(&z))&^0xfff {
    68  		t.Error("C struct field pointer on stack")
    69  	}
    70  }