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-rw-r--r--crates/ra_mbe/src/lib.rs45
-rw-r--r--crates/ra_mbe/src/tests.rs27
2 files changed, 70 insertions, 2 deletions
diff --git a/crates/ra_mbe/src/lib.rs b/crates/ra_mbe/src/lib.rs
index afdbee84e..15f000175 100644
--- a/crates/ra_mbe/src/lib.rs
+++ b/crates/ra_mbe/src/lib.rs
@@ -42,6 +42,8 @@ pub use crate::syntax_bridge::{
42#[derive(Clone, Debug, PartialEq, Eq)] 42#[derive(Clone, Debug, PartialEq, Eq)]
43pub struct MacroRules { 43pub struct MacroRules {
44 pub(crate) rules: Vec<Rule>, 44 pub(crate) rules: Vec<Rule>,
45 /// Highest id of the token we have in TokenMap
46 pub(crate) shift: u32,
45} 47}
46 48
47#[derive(Clone, Debug, PartialEq, Eq)] 49#[derive(Clone, Debug, PartialEq, Eq)]
@@ -50,6 +52,38 @@ pub(crate) struct Rule {
50 pub(crate) rhs: tt::Subtree, 52 pub(crate) rhs: tt::Subtree,
51} 53}
52 54
55// Find the max token id inside a subtree
56fn max_id(subtree: &tt::Subtree) -> Option<u32> {
57 subtree
58 .token_trees
59 .iter()
60 .filter_map(|tt| match tt {
61 tt::TokenTree::Subtree(subtree) => max_id(subtree),
62 tt::TokenTree::Leaf(tt::Leaf::Ident(ident))
63 if ident.id != tt::TokenId::unspecified() =>
64 {
65 Some(ident.id.0)
66 }
67 _ => None,
68 })
69 .max()
70}
71
72/// Shift given TokenTree token id
73fn shift_subtree(tt: &mut tt::Subtree, shift: u32) {
74 for t in tt.token_trees.iter_mut() {
75 match t {
76 tt::TokenTree::Leaf(leaf) => match leaf {
77 tt::Leaf::Ident(ident) if ident.id != tt::TokenId::unspecified() => {
78 ident.id.0 += shift;
79 }
80 _ => (),
81 },
82 tt::TokenTree::Subtree(tt) => shift_subtree(tt, shift),
83 }
84 }
85}
86
53impl MacroRules { 87impl MacroRules {
54 pub fn parse(tt: &tt::Subtree) -> Result<MacroRules, ParseError> { 88 pub fn parse(tt: &tt::Subtree) -> Result<MacroRules, ParseError> {
55 // Note: this parsing can be implemented using mbe machinery itself, by 89 // Note: this parsing can be implemented using mbe machinery itself, by
@@ -72,10 +106,17 @@ impl MacroRules {
72 validate(&rule.lhs)?; 106 validate(&rule.lhs)?;
73 } 107 }
74 108
75 Ok(MacroRules { rules }) 109 // Note that TokenId is started from zero,
110 // We have to add 1 to prevent duplication.
111 let shift = max_id(tt).map_or(0, |it| it + 1);
112 Ok(MacroRules { rules, shift })
76 } 113 }
114
77 pub fn expand(&self, tt: &tt::Subtree) -> Result<tt::Subtree, ExpandError> { 115 pub fn expand(&self, tt: &tt::Subtree) -> Result<tt::Subtree, ExpandError> {
78 mbe_expander::expand(self, tt) 116 // apply shift
117 let mut tt = tt.clone();
118 shift_subtree(&mut tt, self.shift);
119 mbe_expander::expand(self, &tt)
79 } 120 }
80} 121}
81 122
diff --git a/crates/ra_mbe/src/tests.rs b/crates/ra_mbe/src/tests.rs
index f34ab52e1..a23e3afe3 100644
--- a/crates/ra_mbe/src/tests.rs
+++ b/crates/ra_mbe/src/tests.rs
@@ -59,6 +59,33 @@ mod rule_parsing {
59// * Make it pass :-) 59// * Make it pass :-)
60 60
61#[test] 61#[test]
62fn test_token_id_shift() {
63 let macro_definition = r#"
64macro_rules! foobar {
65 ($e:ident) => { foo bar $e }
66}
67"#;
68 let rules = create_rules(macro_definition);
69 let expansion = expand(&rules, "foobar!(baz);");
70
71 fn get_id(t: &tt::TokenTree) -> Option<u32> {
72 if let tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) = t {
73 return Some(ident.id.0);
74 }
75 None
76 }
77
78 assert_eq!(expansion.token_trees.len(), 3);
79 // ($e:ident) => { foo bar $e }
80 // 0 1 2 3 4
81 assert_eq!(get_id(&expansion.token_trees[0]), Some(2));
82 assert_eq!(get_id(&expansion.token_trees[1]), Some(3));
83
84 // So baz should be 5
85 assert_eq!(get_id(&expansion.token_trees[2]), Some(5));
86}
87
88#[test]
62fn test_convert_tt() { 89fn test_convert_tt() {
63 let macro_definition = r#" 90 let macro_definition = r#"
64macro_rules! impl_froms { 91macro_rules! impl_froms {