Initial commit

.hgignore

+^target/
+^.idea/
\ No newline at end of file

Cargo.lock

+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "cfg-if"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "log"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "micro-timer"
+version = "0.1.0"
+dependencies = [
+ "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 1.0.16 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "syn"
+version = "1.0.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "unicode-xid"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[metadata]
+"checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
+"checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
+"checksum proc-macro2 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)" = "6c09721c6781493a2a492a96b5a5bf19b65917fe6728884e7c44dd0c60ca3435"
+"checksum quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "053a8c8bcc71fcce321828dc897a98ab9760bef03a4fc36693c231e5b3216cfe"
+"checksum syn 1.0.16 (registry+https://github.com/rust-lang/crates.io-index)" = "123bd9499cfb380418d509322d7a6d52e5315f064fe4b3ad18a53d6b92c07859"
+"checksum unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"

Cargo.toml

+[package]
+name = "micro-timer"
+version = "0.1.0"
+authors = ["Raphaël Gomès <rgomes@octobus.net>"]
+edition = "2018"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = {version = "1.0.16", features = ["full", "extra-traits"]}
+quote = "1.0.2"
+log = "0.4.8"
\ No newline at end of file

rustfmt.toml

+max_width = 79
+wrap_comments = true
+error_on_line_overflow = true

src/lib.rs

+// micro-timer
+//
+// Copyright 2020, Raphaël Gomès <rgomes@octobus.net>
+
+/// `extern crate` Required even for 2018 edition
+extern crate proc_macro;
+use proc_macro::TokenStream;
+use quote::quote;
+
+type StaticResult<T> = ::std::result::Result<T, &'static str>;
+
+#[proc_macro_attribute]
+pub fn timed(_attr_ts: TokenStream, fn_ts: TokenStream) -> TokenStream {
+    let ast = syn::parse(fn_ts.clone()).unwrap();
+    let func = parse_function(ast).unwrap();
+
+    let mut outer = func.clone();
+    outer.sig.ident = func.sig.ident.to_owned();
+    let original_func_name = func.sig.ident.to_string();
+
+    let inner_block = func.block;
+
+    let block = quote! {
+        {
+            let timer = ::std::time::Instant::now();
+            let mut inner = || { #inner_block };
+            let ret = inner();
+
+            log::trace!(
+                "Elapsed {}: {:?}",
+                #original_func_name,
+                timer.elapsed()
+            );
+
+            ret
+        }
+    };
+    // `quote` works with `proc_macro2::TokenStream`, not
+    // `proc_macro::TokenStream`... thankfully you can just `.into()` them
+    outer.block = syn::parse(block.into()).unwrap();
+
+    (quote! {#outer}).into()
+}
+
+fn parse_function(item: syn::Item) -> StaticResult<syn::ItemFn> {
+    match item {
+        syn::Item::Fn(func) => Ok(func),
+        _ => Err("`time_it` attribute can only be used on functions"),
+    }
+}

tests/tests.rs

+use micro_timer::timed;
+use std::time::Duration;
+
+#[test]
+fn check() {
+    #[timed]
+    fn thing(_value: usize) -> usize {
+        let timer = 10;
+        std::thread::sleep(Duration::from_millis(10));
+        timer
+    }
+
+    assert_eq!(thing(1), 10 as usize);
+}