macros/
helpers.rs

1// SPDX-License-Identifier: GPL-2.0
2
3use proc_macro::{token_stream, Group, Ident, TokenStream, TokenTree};
4
5pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
6    if let Some(TokenTree::Ident(ident)) = it.next() {
7        Some(ident.to_string())
8    } else {
9        None
10    }
11}
12
13pub(crate) fn try_literal(it: &mut token_stream::IntoIter) -> Option<String> {
14    if let Some(TokenTree::Literal(literal)) = it.next() {
15        Some(literal.to_string())
16    } else {
17        None
18    }
19}
20
21pub(crate) fn try_string(it: &mut token_stream::IntoIter) -> Option<String> {
22    try_literal(it).and_then(|string| {
23        if string.starts_with('\"') && string.ends_with('\"') {
24            let content = &string[1..string.len() - 1];
25            if content.contains('\\') {
26                panic!("Escape sequences in string literals not yet handled");
27            }
28            Some(content.to_string())
29        } else if string.starts_with("r\"") {
30            panic!("Raw string literals are not yet handled");
31        } else {
32            None
33        }
34    })
35}
36
37pub(crate) fn expect_ident(it: &mut token_stream::IntoIter) -> String {
38    try_ident(it).expect("Expected Ident")
39}
40
41pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char {
42    if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") {
43        punct.as_char()
44    } else {
45        panic!("Expected Punct");
46    }
47}
48
49pub(crate) fn expect_string(it: &mut token_stream::IntoIter) -> String {
50    try_string(it).expect("Expected string")
51}
52
53pub(crate) fn expect_string_ascii(it: &mut token_stream::IntoIter) -> String {
54    let string = try_string(it).expect("Expected string");
55    assert!(string.is_ascii(), "Expected ASCII string");
56    string
57}
58
59pub(crate) fn expect_group(it: &mut token_stream::IntoIter) -> Group {
60    if let TokenTree::Group(group) = it.next().expect("Reached end of token stream for Group") {
61        group
62    } else {
63        panic!("Expected Group");
64    }
65}
66
67pub(crate) fn expect_end(it: &mut token_stream::IntoIter) {
68    if it.next().is_some() {
69        panic!("Expected end");
70    }
71}
72
73/// Given a function declaration, finds the name of the function.
74pub(crate) fn function_name(input: TokenStream) -> Option<Ident> {
75    let mut input = input.into_iter();
76    while let Some(token) = input.next() {
77        match token {
78            TokenTree::Ident(i) if i.to_string() == "fn" => {
79                if let Some(TokenTree::Ident(i)) = input.next() {
80                    return Some(i);
81                }
82                return None;
83            }
84            _ => continue,
85        }
86    }
87    None
88}
macros/helpers.rs

macros/
helpers.rs
