| 66 | } |
| 67 | |
| 68 | fn probe_layout_of(typedef: &str) -> anyhow::Result<Layout> { |
| 69 | log::trace!("Probing {typedef} ..."); |
| 70 | let mut src = "extern crate alloc;\n".to_string(); |
| 71 | write!(src, "{}", typedef)?; |
| 72 | write!( |
| 73 | src, |
| 74 | r#" |
| 75 | fn main() {{ |
| 76 | let layout = core::alloc::Layout::new::<T>(); |
| 77 | println!("size = {{}}", layout.size()); |
| 78 | println!("align = {{}}", layout.align()); |
| 79 | }} |
| 80 | "# |
| 81 | )?; |
| 82 | let obj = compile_rust_program(&src).with_context(|| format!("Fail to compile: `{src}`"))?; |
| 83 | let result = execute_rust_program(&obj).with_context(|| format!("Fail to run: `{obj}`"))?; |
| 84 | let mut lines = result.lines(); |
| 85 | let line = lines.next().context("has next")?; |
| 86 | let (attr, size) = line.split_once(" = ").context("attr")?; |
| 87 | assert_eq!(attr, "size"); |
| 88 | let line = lines.next().context("has next")?; |
| 89 | let (attr, align) = line.split_once(" = ").context("attr")?; |
| 90 | assert_eq!(attr, "align"); |
| 91 | let size: usize = size |
| 92 | .parse() |
| 93 | .with_context(|| format!("Not size: `{size}`"))?; |
| 94 | let align: usize = align |
| 95 | .parse() |
| 96 | .with_context(|| format!("Not align: `{align}`"))?; |
| 97 | let layout = Layout::from_size_align(size, align)?; |
| 98 | log::trace!("{layout:?}"); |
| 99 | Ok(layout) |
| 100 | } |
| 101 | |
| 102 | #[cfg(test)] |
| 103 | mod test { |