Upgrade rust/crates/proc-macro-nested to 0.1.6
* Keep local changes:
* src/lib.rs (include out/count.rs)
* out/count.rs (copied from new cargo build)
Test: make
Change-Id: I83865b32b0675023e29da3fb62207cebe42f487b
diff --git a/build.rs b/build.rs
index b4aec63..ef56f8e 100644
--- a/build.rs
+++ b/build.rs
@@ -1,6 +1,5 @@
use std::env;
-use std::fs::File;
-use std::io::Write;
+use std::fs;
use std::iter;
use std::path::Path;
@@ -16,26 +15,32 @@
*/
fn main() {
- let out_dir = env::var("OUT_DIR").unwrap();
- let dest_path = Path::new(&out_dir).join("count.rs");
- let mut f = File::create(&dest_path).unwrap();
+ // Tell Cargo not to rerun on src/lib.rs changes.
+ println!("cargo:rerun-if-changed=build.rs");
let mut content = String::new();
- content += "
- #[doc(hidden)]
- #[macro_export]
- macro_rules! count {
- ";
+ content += "#[doc(hidden)]\n";
+ content += "#[macro_export]\n";
+ content += "macro_rules! count {\n";
for i in 0..=64 {
let bangs = iter::repeat("!").take(i).collect::<String>();
- content += &format!("({}) => {{ proc_macro_call_{}!() }};", bangs, i);
+ content += &format!(" ({}) => {{ proc_macro_call_{}!() }};\n", bangs, i);
}
- content += "
- ($(!)+) => {
- compile_error!(\"this macro does not support >64 nested macro invocations\")
- };
- }
- ";
+ content += " ($(!)+) => {\n";
+ content += " compile_error! { \"this macro does not support >64 nested macro invocations\" }\n";
+ content += " };\n";
+ content += "}\n";
- f.write_all(content.as_bytes()).unwrap();
+ let content = content.as_bytes();
+ let out_dir = env::var("OUT_DIR").unwrap();
+ let ref dest_path = Path::new(&out_dir).join("count.rs");
+
+ // Avoid bumping filetime if content is up to date. Possibly related to
+ // https://github.com/dtolnay/proc-macro-hack/issues/56 ...?
+ if fs::read(dest_path)
+ .map(|existing| existing != content)
+ .unwrap_or(true)
+ {
+ fs::write(dest_path, content).unwrap();
+ }
}
