From cb7ada5409f171dae364f206a7fe3ff30fcba7cb Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 12 Nov 2024 11:52:23 +0100 Subject: rust: allow using build-root bindings.rs from cargo Right now, using cargo with QEMU requires copying by hand the bindings.rs to the source tree. Instead, we can use an include file to escape the cage of cargo's mandated source directory structure. By running cargo within meson's "devenv" and adding a MESON_BUILD_ROOT environment variable, it is easy for build.rs to find the file. However, the file must be symlinked into cargo's output directory for rust-analyzer to find it. Suggested-by: Junjie Mao Signed-off-by: Paolo Bonzini --- rust/qemu-api/build.rs | 34 +++++++++++++++++++++++++++------- 1 file changed, 27 insertions(+), 7 deletions(-) (limited to 'rust/qemu-api/build.rs') diff --git a/rust/qemu-api/build.rs b/rust/qemu-api/build.rs index 20f8f71..40644d5 100644 --- a/rust/qemu-api/build.rs +++ b/rust/qemu-api/build.rs @@ -2,17 +2,36 @@ // Author(s): Manos Pitsidianakis // SPDX-License-Identifier: GPL-2.0-or-later -use std::path::Path; +#[cfg(unix)] +use std::os::unix::fs::symlink as symlink_file; +#[cfg(windows)] +use std::os::windows::fs::symlink_file; +use std::{env, fs::remove_file, io::Result, path::Path}; use version_check as rustc; -fn main() { - if !Path::new("src/bindings.rs").exists() { - panic!( - "No generated C bindings found! Either build them manually with bindgen or with meson \ - (`ninja bindings.rs`) and copy them to src/bindings.rs, or build through meson." - ); +fn main() -> Result<()> { + // Placing bindings.inc.rs in the source directory is supported + // but not documented or encouraged. + let path = env::var("MESON_BUILD_ROOT") + .unwrap_or_else(|_| format!("{}/src", env!("CARGO_MANIFEST_DIR"))); + + let file = format!("{}/bindings.inc.rs", path); + let file = Path::new(&file); + if !Path::new(&file).exists() { + panic!(concat!( + "No generated C bindings found! If you want to run `cargo`, start a subshell\n", + "with `meson devenv`, or point MESON_BUILD_ROOT to the top of the build tree." + )); + } + + let out_dir = env::var("OUT_DIR").unwrap(); + let dest_path = format!("{}/bindings.inc.rs", out_dir); + let dest_path = Path::new(&dest_path); + if dest_path.symlink_metadata().is_ok() { + remove_file(dest_path)?; } + symlink_file(file, dest_path)?; // Check for available rustc features if rustc::is_min_version("1.77.0").unwrap_or(false) { @@ -20,4 +39,5 @@ fn main() { } println!("cargo:rerun-if-changed=build.rs"); + Ok(()) } -- cgit v1.1