File: demo-allocator-54478.rs

package info (click to toggle)
rustc 1.85.0%2Bdfsg3-1
  • links: PTS, VCS
  • area: main
  • in suites: experimental, sid, trixie
  • size: 893,396 kB
  • sloc: xml: 158,127; python: 35,830; javascript: 19,497; cpp: 19,002; sh: 17,245; ansic: 13,127; asm: 4,376; makefile: 1,051; perl: 29; lisp: 29; ruby: 19; sql: 11
file content (46 lines) | stat: -rw-r--r-- 1,251 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
// https://github.com/rust-lang/rust/issues/54478
#![crate_name="foo"]

// Issue #54478: regression test showing that we can demonstrate
// `#[global_allocator]` in code blocks built by `rustdoc`.
//
// ## Background
//
// Changes in lang-item visibility injected failures that were only
// exposed when compiling with `-C prefer-dynamic`. But `rustdoc` used
// `-C prefer-dynamic` (and had done so for years, for reasons we did
// not document at that time).
//
// Rather than try to revise the visbility semanics, we instead
// decided to change `rustdoc` to behave more like the compiler's
// default setting, by leaving off `-C prefer-dynamic`.

//@ compile-flags:--test

//! This is a doc comment
//!
//! ```rust
//! use std::alloc::*;
//!
//! #[global_allocator]
//! static ALLOC: A = A;
//!
//! static mut HIT: bool = false;
//!
//! struct A;
//!
//! unsafe impl GlobalAlloc for A {
//!     unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
//!         HIT = true;
//!         System.alloc(layout)
//!     }
//!     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
//!         System.dealloc(ptr, layout);
//!     }
//! }
//!
//! fn main() {
//!     drop(String::from("An allocation"));
//!     assert!(unsafe { HIT });
//! }
//! ```