FTBFS on 1.26.0-nightly (80785a547 2018-03-30)

[kivikakk]

Hey there,

meta currently fails to build from source on nightly:

$ cargo build
   Compiling pest_meta v2.0.0 (file:///Users/kivikakk/Code/pest-parser/pest/meta)
error[E0518]: attribute should be applied to function
  --> meta/src/parser.rs:21:10
   |
21 | #[derive(Parser)]
   |          ^^^^^^ not a function

error: aborting due to previous error

For more information about this error, try `rustc --explain E0518`.
error: Could not compile `pest_meta`.

To learn more, run the command again with --verbose.

The pest_derive from crates.io it's using is 1.0.6.

E0158 appears to be #[inline(…)] applied to a non-function:

This error indicates that an `#[inline(..)]` attribute was incorrectly placed
on something other than a function or method.

I've tried looking at the generated code with --pretty=expanded and … well, there's a lot of inlines, and I can't easily find one that doesn't correspond with a fn or lambda.

I can't easily find a change in rustc itself that would've caused this … so I'm going to try manually bisecting by installing nightlies that correspond to changes in the relevant code, i.e. https://github.com/rust-lang/rust/commits/361509320c882ee76f0d1359f842dec4637e6b08/src/librustc/hir/check_attr.rs. Wish me luck!

[kivikakk]

• ✅ 2018-03-28
• ❌ 2018-03-29

The one change to that file was the merge of rust-lang/rust#49291.

[kivikakk]

It looks like it's complaining about #[inline] as applied to lambdas: rust-lang/rust#49291 (comment)

[kivikakk]

Turns out #[inline] never had an effect on lambdas! rust-lang/rust#49291 (comment)

I'll open a PR here.

[dragostis]

The reason I've added the inlines was because deeply nested labdas would not get inlined. (I checked the assembly) This was causing extra moves of some fat pointers (when changing from the Rc input to &str) and was solved by using the inlines. I cannot check right now, but removing the inlines might cause a dip in performance. You can check to see whether there's a difference by running the benchmark in grammars.

[kivikakk]

master:

     Running /Users/kivikakk/Code/pest-parser/pest/target/release/deps/json-05d1fc53b4dd1f96

running 1 test
test data ... bench:      14,324 ns/iter (+/- 2,841)

#219:

     Running /Users/kivikakk/Code/pest-parser/pest/target/release/deps/json-05d1fc53b4dd1f96

running 1 test
test data ... bench:      14,256 ns/iter (+/- 4,804)

[technetos]

Thanks so much ❤️