token-goblin 0.1.0

Inline procedural macros without a separate proc-macro crate.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88

//! Support of rust-analyzer macro expansion:
//!
//! - Check if we under r-a expansion,
//! - emit special helper module with original source text as it would be written into impl module,
//! - ensure that same libraries are used through `extern crate ...`,
//!
//!

use std::path::Path;

use proc_macro2::TokenStream;
use quote::{format_ident, quote};

use crate::{
    macro_impl::{Config, Lazieness},
    metadata::cargo_crate_name,
    template::TemplateContext,
};

/// Returns true if proc-server is IDE.
/// (Currently only `rust-analyzer` is supported)
fn is_ide() -> bool {
    // current process is rust-analyzer
    std::env::current_exe()
        .ok()
        .as_deref()
        .and_then(Path::file_name)
        .map_or_else(|| "unknown".into(), |s| s.to_string_lossy().into_owned())
        .contains("rust-analyzer")
    || // RUST_ANALYZER_INTERNALS_DO_NOT_USE=this is unstable"
    std::env::var("RUST_ANALYZER_INTERNALS_DO_NOT_USE").unwrap_or_default() == "this is unstable"
}

fn format_ide_helper_mod(template_context: &TemplateContext) -> TokenStream {
    let deps = template_context
        .source_metadata
        .dependencies
        .iter()
        .map(|dep| {
            let name = cargo_crate_name(&dep.name);
            let name = format_ident!("{}", name);

            quote! {
                extern crate #name;
            }
        })
        .collect::<Vec<_>>();
    let content = &template_context.generated_content;
    let mod_name = format_ident!(
        "__ide_tg_helper_{}",
        cargo_crate_name(&template_context.package_name)
    );
    quote! {
        mod #mod_name {
            extern crate token_goblin_runtime;
            use token_goblin_runtime::prelude::*;
            // We need to provide dummy implementations of quote and output macros,
            // firstly to speedup expansion, secondly because R-A sometimes crashes on them.
            macro_rules! quote {
                ($($tokens:tt)*) => {{
                    /// NOTE: This is expansion of dummy output impl.
                    const _: () = ();
                    TokenStream::new()
                }}
            }
            macro_rules! output {
                ($($tokens:tt)*) => {

                    {let _ = quote!($($tokens)*);}
                }
            }
            #(#deps)*
            #content
        }
    }
}

pub fn emit_ide_helper_mod(template_context: &TemplateContext, config: &Config) -> TokenStream {
    if is_ide() && !config.no_ide_helper {
        format_ide_helper_mod(template_context)
    } else {
        TokenStream::new()
    }
}

pub fn is_lazy(config: &Config) -> bool {
    config.lazy == Lazieness::Enforced || (config.lazy == Lazieness::Default && is_ide())
}