notinheap2.go

     1  // errorcheck -+
     2  
     3  // Copyright 2016 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  // Test walk errors for not-in-heap.
     8  
     9  //go:build cgo
    10  
    11  package p
    12  
    13  import "runtime/cgo"
    14  
    15  type nih struct {
    16  	_    cgo.Incomplete
    17  	next *nih
    18  }
    19  
    20  // Global variables are okay.
    21  
    22  var x nih
    23  
    24  // Stack variables are not okay.
    25  
    26  func f() {
    27  	var y nih // ERROR "nih is incomplete \(or unallocatable\); stack allocation disallowed"
    28  	x = y
    29  }
    30  
    31  // Heap allocation is not okay.
    32  
    33  var y *nih
    34  var y2 *struct{ x nih }
    35  var y3 *[1]nih
    36  var z []nih
    37  var w []nih
    38  var n int
    39  var sink interface{}
    40  
    41  type embed1 struct { // implicitly notinheap
    42  	x nih
    43  }
    44  
    45  type embed2 [1]nih // implicitly notinheap
    46  
    47  type embed3 struct { // implicitly notinheap
    48  	x [1]nih
    49  }
    50  
    51  // Type aliases inherit the go:notinheap-ness of the type they alias.
    52  type nihAlias = nih
    53  
    54  type embedAlias1 struct { // implicitly notinheap
    55  	x nihAlias
    56  }
    57  type embedAlias2 [1]nihAlias // implicitly notinheap
    58  
    59  func g() {
    60  	y = new(nih)              // ERROR "can't be allocated in Go"
    61  	y2 = new(struct{ x nih }) // ERROR "can't be allocated in Go"
    62  	y3 = new([1]nih)          // ERROR "can't be allocated in Go"
    63  	z = make([]nih, 1)        // ERROR "can't be allocated in Go"
    64  	z = append(z, x)          // ERROR "can't be allocated in Go"
    65  
    66  	sink = new(embed1)      // ERROR "can't be allocated in Go"
    67  	sink = new(embed2)      // ERROR "can't be allocated in Go"
    68  	sink = new(embed3)      // ERROR "can't be allocated in Go"
    69  	sink = new(embedAlias1) // ERROR "can't be allocated in Go"
    70  	sink = new(embedAlias2) // ERROR "can't be allocated in Go"
    71  
    72  	// Test for special case of OMAKESLICECOPY
    73  	x := make([]nih, n) // ERROR "can't be allocated in Go"
    74  	copy(x, z)
    75  	z = x
    76  }
    77  
    78  // Writes don't produce write barriers.
    79  
    80  var p *nih
    81  
    82  //go:nowritebarrier
    83  func h() {
    84  	y.next = p.next
    85  }
    86
View as plain text