Result from running on a few crates

[mcarton]

PR on racer: racer-rust/racer#472
PR on rustful: Ogeon/rustful#91
PR on rust-bindgen: https://github.com/crabtw/rust-bindgen/pull/252
PR on quickcheck: BurntSushi/quickcheck#118
PR on Cargo: rust-lang/cargo#2282

Results

On cargo

warnings before:
     cmp_owned : 2
     cyclomatic_complexity : 1
     deprecated : 11
     explicit_iter_loop : 57
     identity_op : 3
     len_without_is_empty : 3
     len_zero : 20
     let_and_return : 3
     map_clone : 14
     needless_lifetimes : 4
     needless_return : 24
     ok_expect : 2
     option_map_unwrap_or : 10
     private_in_public : 28
     redundant_closure : 2
     should_implement_trait : 2
     single_match : 3
     str_to_string : 112
     string_to_string : 12
     type_complexity : 3
     unnecessary_mut_passed : 2
     unneeded_field_pattern : 3
     unused_lifetimes : 1
     unused_variables : 2
     while_let_loop : 2

warnings after:
     cmp_owned : 2
     cyclomatic_complexity : 1
     identity_op : 1
     let_and_return : 3
     map_clone : 1
     needless_return : 3
     ok_expect : 2
     option_map_unwrap_or : 1
     private_in_public : 28
     should_implement_trait : 2
     str_to_string : 80
     type_complexity : 3
     while_let_loop : 2

• needless_return needs a macro check;
• let_and_return should ignore:

    let foo : type = …;
    type

• while_let_loop should ignore cases where the iterator is next()-ed somewhere else in the loop;
• this:

    ret.to_doc_test = to_builds.iter().map(|&p| p.clone()).collect();

could not use cloned() as suggested by map_clone;

• ok_expect was not on Rust 1.2, which is still supported by Cargo.

On racer

warnings before: https://gist.github.com/mcarton/3496037f45d315bedc9a#file-before
     cyclomatic_complexity : 4
     collapsible_if : 1
     toplevel_ref_arg : 9
     used_underscore_binding : 2
     wrong_self_convention : 1
     explicit_counter_loop : 5
     ptr_arg : 1
     type_complexity : 1
     str_to_string : 9
     match_ref_pats : 3

warnings after: https://gist.github.com/mcarton/3496037f45d315bedc9a#file-after
     wrong_self_convention : 1
     cyclomatic_complexity : 4
     explicit_counter_loop : 1
     type_complexity : 1
     str_to_string : 4

str_to_string needs a macro check. (#566)
I did not fix the explicit_counter_loop because of types (it'd need a cast u32 ↔ usize cast IIRC). This needs discussion.

On rustful

warnings before: https://gist.github.com/mcarton/6411c8526dee7b12632b#file-before
     match_ref_pats : 6
     cyclomatic_complexity : 13
     option_map_unwrap_or_else : 1
     type_complexity : 3
     while_let_on_iterator : 1
     ptr_arg : 1
     needless_lifetimes : 9
     redundant_closure : 7

warnings after: https://gist.github.com/mcarton/6411c8526dee7b12632b#file-after
     type_complexity : 3
     cyclomatic_complexity : 13
     needless_lifetimes : 7

I think most if not all of the needless_lifetimes are false positive (#599) and I don't think RouteIter<Split<'a, u8, fn(&u8) -> bool>> is that bad a type.

On rust-bindgen

warnings before:
     len_zero : 1
     used_underscore_binding : 3
     ok_expect : 1
     unknown_lints : 1
     unused_lifetimes : 2
     explicit_iter_loop : 2
     toplevel_ref_arg : 3
     string_to_string : 1
     needless_return : 51
     match_bool : 2
     collapsible_if : 1
     needless_lifetimes : 2
     unused_imports : 1
     ptr_arg : 5
     str_to_string : 41
     match_ref_pats : 9
     needless_range_loop : 1

warnings after:
     needless_lifetimes : 1

Again, I think the remaining needless_lifetimes is a false positive.

On quickcheck

warnings before:
     needless_return : 4
     len_zero : 1
     match_ref_pats : 1
     let_and_return : 1
     needless_range_loop : 1
     linkedlist : 4
     match_bool : 1

warnings after:
     linkedlist : 4

I don't think linkedlist should lint when implementing a public trait on LinkedList<_>: The trait is only implemented in case users would want to use LinkedList<_>, that's not a use of LinkedList<_> in the library itself.

Cyclomatic complexity lint

The cyclomatic complexity warns about:

in Cargo:
     39 : 1 fn
in racer:
     27 : 1 fn
     29 : 1 fn
     30 : 1 fn
     32 : 1 fn
in rustful:
     31 : 2 fn
     41 : 1 fn
     51 : 8 fn
     61 : 2 fn
in rust-bindgen and quickcheck:
     None :)

In rustful all of them are unfair because caused by calls to a relatively sane macro.

[mcarton]

Just added Cargo.

[oli-obk]

The CC-lint should be ignoring macros. I'll have to investigate that.

[Manishearth]

Thanks for doing this! Most of these seem easy to fix, I'll have a go at fixing them Monday if someone doesn't do it first.

[phansch]

Going to close this as this issue is almost 3 years old and Clippy has come a long way since then ⌛