build_features/
lib.rs

1extern crate proc_macro;
2use proc_macro::TokenStream;
3
4#[proc_macro]
5pub fn get_enabled_features(_cargo_file: TokenStream) -> TokenStream {
6    //https://www.reddit.com/r/rust/comments/834g53/list_of_conditional_compilation_features_at/
7    let features_gen_code = r#"
8    let enabled_features = (|| -> Vec<&'static str>{
9            macro_rules! make_feat_list {
10                ($($feat:expr),*) => {
11                    vec![ 
12                        $(
13                            #[cfg(feature = $feat)]
14                            $feat,
15                        )* 
16                    ]
17                }
18            }
19            make_feat_list!(FEATURES)
20        })();
21    "#;
22
23    let mut args = std::env::args().skip_while(|val| !val.starts_with("--manifest-path"));
24
25    let mut cmd = cargo_metadata::MetadataCommand::new();
26    match args.next() {
27        Some(ref p) if p == "--manifest-path" => {
28            cmd.manifest_path(args.next().unwrap());
29        }
30        Some(p) => {
31            cmd.manifest_path(p.trim_start_matches("--manifest-path="));
32        }
33        None => {}
34    };
35
36    let metadata = cmd
37        .features(cargo_metadata::CargoOpt::AllFeatures)
38        .exec()
39        .unwrap();
40
41    //Get string of features
42    let root_package_features = format!(
43        "{:?}",
44        metadata
45            .root_package()
46            .unwrap()
47            .features
48            .keys()
49            .cloned()
50            .collect::<Vec<String>>()
51    );
52
53    //Without '[' in the  begin and ']' in the end
54    let slice_features = &root_package_features[1..root_package_features.len() - 1];
55
56    let features_gen_code = features_gen_code.replace("FEATURES", slice_features);
57
58    features_gen_code.parse().unwrap()
59}
build_features/lib.rs

build_features/
lib.rs
