Source file test/fixedbugs/issue40954.go

     1  // run
     2  
     3  // Copyright 2020 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  //go:build cgo
     8  
     9  package main
    10  
    11  import (
    12  	"runtime/cgo"
    13  	"unsafe"
    14  )
    15  
    16  type S struct {
    17  	_ cgo.Incomplete
    18  	x int
    19  }
    20  
    21  func main() {
    22  	var i int
    23  	p := (*S)(unsafe.Pointer(uintptr(unsafe.Pointer(&i))))
    24  	v := uintptr(unsafe.Pointer(p))
    25  	// p is a pointer to a not-in-heap type. Like some C libraries,
    26  	// we stored an integer in that pointer. That integer just happens
    27  	// to be the address of i.
    28  	// v is also the address of i.
    29  	// p has a base type which is marked not-in-heap, so it
    30  	// should not be adjusted when the stack is copied.
    31  	recurse(100, p, v)
    32  }
    33  
    34  //go:noinline
    35  func recurse(n int, p *S, v uintptr) {
    36  	if n > 0 {
    37  		recurse(n-1, p, v)
    38  	}
    39  	if uintptr(unsafe.Pointer(p)) != v {
    40  		panic("adjusted notinheap pointer")
    41  	}
    42  }
    43  

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