rune/macros/
macro_compiler.rs

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1//! Macro compiler.
2
3use crate::alloc::prelude::*;
4use crate::ast;
5use crate::ast::Spanned;
6use crate::compile::{self, ErrorKind, ItemMeta};
7use crate::indexing::Indexer;
8use crate::macros::{MacroContext, ToTokens};
9use crate::parse::{Parse, Parser};
10
11use super::TokenStream;
12
13pub(crate) struct MacroCompiler<'a, 'b, 'arena> {
14    pub(crate) item_meta: ItemMeta,
15    pub(crate) idx: &'a mut Indexer<'b, 'arena>,
16}
17
18impl MacroCompiler<'_, '_, '_> {
19    /// Compile the given macro into the given output type.
20    pub(crate) fn eval_macro<T>(&mut self, macro_call: &ast::MacroCall) -> compile::Result<T>
21    where
22        T: Parse,
23    {
24        let span = macro_call.span();
25
26        if !self.idx.q.options.macros {
27            return Err(compile::Error::msg(
28                span,
29                "macros must be enabled with `-O macros=true`",
30            ));
31        }
32
33        let named = self.idx.q.convert_path(&macro_call.path)?;
34        let hash = self.idx.q.pool.item_type_hash(named.item);
35
36        let Some(handler) = self.idx.q.context.lookup_macro(hash) else {
37            return Err(compile::Error::new(
38                span,
39                ErrorKind::MissingMacro {
40                    item: self.idx.q.pool.item(named.item).try_to_owned()?,
41                },
42            ));
43        };
44
45        let input_stream = &macro_call.input;
46
47        let token_stream = {
48            let mut macro_context = MacroContext {
49                macro_span: span,
50                input_span: macro_call.input_span(),
51                item_meta: self.item_meta,
52                idx: self.idx,
53            };
54
55            handler(&mut macro_context, input_stream)?
56        };
57
58        let mut parser = Parser::from_token_stream(&token_stream, span);
59        let output = parser.parse::<T>()?;
60        parser.eof()?;
61
62        Ok(output)
63    }
64
65    /// Compile the given macro into the given output type.
66    pub(crate) fn eval_attribute_macro<T>(
67        &mut self,
68        attribute: &ast::Attribute,
69        item: &ast::Item,
70    ) -> compile::Result<Option<T>>
71    where
72        T: Parse,
73    {
74        let span = attribute.span();
75
76        if !self.idx.q.options.macros {
77            return Ok(None);
78        }
79
80        let named = self.idx.q.convert_path(&attribute.path)?;
81
82        let hash = self.idx.q.pool.item_type_hash(named.item);
83
84        let handler = match self.idx.q.context.lookup_attribute_macro(hash) {
85            Some(handler) => handler,
86            None => {
87                return Ok(None);
88            }
89        };
90
91        let input_stream = &attribute.input;
92
93        let token_stream = {
94            let mut macro_context = MacroContext {
95                macro_span: attribute.span(),
96                input_span: attribute.input_span(),
97                item_meta: self.item_meta,
98                idx: self.idx,
99            };
100
101            let mut item_stream = TokenStream::new();
102            item.to_tokens(&mut macro_context, &mut item_stream)?;
103
104            handler(&mut macro_context, input_stream, &item_stream)?
105        };
106
107        let mut parser = Parser::from_token_stream(&token_stream, span);
108
109        parser.parse_all().map(Some)
110    }
111}
rune/macros/macro_compiler.rs

rune/macros/
macro_compiler.rs
