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-rw-r--r--crates/cfg/Cargo.toml18
-rw-r--r--crates/cfg/src/cfg_expr.rs133
-rw-r--r--crates/cfg/src/lib.rs51
3 files changed, 202 insertions, 0 deletions
diff --git a/crates/cfg/Cargo.toml b/crates/cfg/Cargo.toml
new file mode 100644
index 000000000..d2ea551d1
--- /dev/null
+++ b/crates/cfg/Cargo.toml
@@ -0,0 +1,18 @@
1[package]
2name = "cfg"
3version = "0.0.0"
4license = "MIT OR Apache-2.0"
5authors = ["rust-analyzer developers"]
6edition = "2018"
7
8[lib]
9doctest = false
10
11[dependencies]
12rustc-hash = "1.1.0"
13
14tt = { path = "../tt" }
15
16[dev-dependencies]
17mbe = { path = "../mbe" }
18syntax = { path = "../syntax" }
diff --git a/crates/cfg/src/cfg_expr.rs b/crates/cfg/src/cfg_expr.rs
new file mode 100644
index 000000000..336fe25bc
--- /dev/null
+++ b/crates/cfg/src/cfg_expr.rs
@@ -0,0 +1,133 @@
1//! The condition expression used in `#[cfg(..)]` attributes.
2//!
3//! See: https://doc.rust-lang.org/reference/conditional-compilation.html#conditional-compilation
4
5use std::slice::Iter as SliceIter;
6
7use tt::SmolStr;
8
9#[derive(Debug, Clone, PartialEq, Eq)]
10pub enum CfgExpr {
11 Invalid,
12 Atom(SmolStr),
13 KeyValue { key: SmolStr, value: SmolStr },
14 All(Vec<CfgExpr>),
15 Any(Vec<CfgExpr>),
16 Not(Box<CfgExpr>),
17}
18
19impl CfgExpr {
20 pub fn parse(tt: &tt::Subtree) -> CfgExpr {
21 next_cfg_expr(&mut tt.token_trees.iter()).unwrap_or(CfgExpr::Invalid)
22 }
23 /// Fold the cfg by querying all basic `Atom` and `KeyValue` predicates.
24 pub fn fold(&self, query: &dyn Fn(&SmolStr, Option<&SmolStr>) -> bool) -> Option<bool> {
25 match self {
26 CfgExpr::Invalid => None,
27 CfgExpr::Atom(name) => Some(query(name, None)),
28 CfgExpr::KeyValue { key, value } => Some(query(key, Some(value))),
29 CfgExpr::All(preds) => {
30 preds.iter().try_fold(true, |s, pred| Some(s && pred.fold(query)?))
31 }
32 CfgExpr::Any(preds) => {
33 preds.iter().try_fold(false, |s, pred| Some(s || pred.fold(query)?))
34 }
35 CfgExpr::Not(pred) => pred.fold(query).map(|s| !s),
36 }
37 }
38}
39
40fn next_cfg_expr(it: &mut SliceIter<tt::TokenTree>) -> Option<CfgExpr> {
41 let name = match it.next() {
42 None => return None,
43 Some(tt::TokenTree::Leaf(tt::Leaf::Ident(ident))) => ident.text.clone(),
44 Some(_) => return Some(CfgExpr::Invalid),
45 };
46
47 // Peek
48 let ret = match it.as_slice().first() {
49 Some(tt::TokenTree::Leaf(tt::Leaf::Punct(punct))) if punct.char == '=' => {
50 match it.as_slice().get(1) {
51 Some(tt::TokenTree::Leaf(tt::Leaf::Literal(literal))) => {
52 it.next();
53 it.next();
54 // FIXME: escape? raw string?
55 let value =
56 SmolStr::new(literal.text.trim_start_matches('"').trim_end_matches('"'));
57 CfgExpr::KeyValue { key: name, value }
58 }
59 _ => return Some(CfgExpr::Invalid),
60 }
61 }
62 Some(tt::TokenTree::Subtree(subtree)) => {
63 it.next();
64 let mut sub_it = subtree.token_trees.iter();
65 let mut subs = std::iter::from_fn(|| next_cfg_expr(&mut sub_it)).collect();
66 match name.as_str() {
67 "all" => CfgExpr::All(subs),
68 "any" => CfgExpr::Any(subs),
69 "not" => CfgExpr::Not(Box::new(subs.pop().unwrap_or(CfgExpr::Invalid))),
70 _ => CfgExpr::Invalid,
71 }
72 }
73 _ => CfgExpr::Atom(name),
74 };
75
76 // Eat comma separator
77 if let Some(tt::TokenTree::Leaf(tt::Leaf::Punct(punct))) = it.as_slice().first() {
78 if punct.char == ',' {
79 it.next();
80 }
81 }
82 Some(ret)
83}
84
85#[cfg(test)]
86mod tests {
87 use super::*;
88
89 use mbe::ast_to_token_tree;
90 use syntax::ast::{self, AstNode};
91
92 fn assert_parse_result(input: &str, expected: CfgExpr) {
93 let (tt, _) = {
94 let source_file = ast::SourceFile::parse(input).ok().unwrap();
95 let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
96 ast_to_token_tree(&tt).unwrap()
97 };
98 let cfg = CfgExpr::parse(&tt);
99 assert_eq!(cfg, expected);
100 }
101
102 #[test]
103 fn test_cfg_expr_parser() {
104 assert_parse_result("#![cfg(foo)]", CfgExpr::Atom("foo".into()));
105 assert_parse_result("#![cfg(foo,)]", CfgExpr::Atom("foo".into()));
106 assert_parse_result(
107 "#![cfg(not(foo))]",
108 CfgExpr::Not(Box::new(CfgExpr::Atom("foo".into()))),
109 );
110 assert_parse_result("#![cfg(foo(bar))]", CfgExpr::Invalid);
111
112 // Only take the first
113 assert_parse_result(r#"#![cfg(foo, bar = "baz")]"#, CfgExpr::Atom("foo".into()));
114
115 assert_parse_result(
116 r#"#![cfg(all(foo, bar = "baz"))]"#,
117 CfgExpr::All(vec![
118 CfgExpr::Atom("foo".into()),
119 CfgExpr::KeyValue { key: "bar".into(), value: "baz".into() },
120 ]),
121 );
122
123 assert_parse_result(
124 r#"#![cfg(any(not(), all(), , bar = "baz",))]"#,
125 CfgExpr::Any(vec![
126 CfgExpr::Not(Box::new(CfgExpr::Invalid)),
127 CfgExpr::All(vec![]),
128 CfgExpr::Invalid,
129 CfgExpr::KeyValue { key: "bar".into(), value: "baz".into() },
130 ]),
131 );
132 }
133}
diff --git a/crates/cfg/src/lib.rs b/crates/cfg/src/lib.rs
new file mode 100644
index 000000000..a9d50e698
--- /dev/null
+++ b/crates/cfg/src/lib.rs
@@ -0,0 +1,51 @@
1//! cfg defines conditional compiling options, `cfg` attibute parser and evaluator
2
3mod cfg_expr;
4
5use rustc_hash::FxHashSet;
6use tt::SmolStr;
7
8pub use cfg_expr::CfgExpr;
9
10/// Configuration options used for conditional compilition on items with `cfg` attributes.
11/// We have two kind of options in different namespaces: atomic options like `unix`, and
12/// key-value options like `target_arch="x86"`.
13///
14/// Note that for key-value options, one key can have multiple values (but not none).
15/// `feature` is an example. We have both `feature="foo"` and `feature="bar"` if features
16/// `foo` and `bar` are both enabled. And here, we store key-value options as a set of tuple
17/// of key and value in `key_values`.
18///
19/// See: https://doc.rust-lang.org/reference/conditional-compilation.html#set-configuration-options
20#[derive(Debug, Clone, PartialEq, Eq, Default)]
21pub struct CfgOptions {
22 atoms: FxHashSet<SmolStr>,
23 key_values: FxHashSet<(SmolStr, SmolStr)>,
24}
25
26impl CfgOptions {
27 pub fn check(&self, cfg: &CfgExpr) -> Option<bool> {
28 cfg.fold(&|key, value| match value {
29 None => self.atoms.contains(key),
30 Some(value) => self.key_values.contains(&(key.clone(), value.clone())),
31 })
32 }
33
34 pub fn insert_atom(&mut self, key: SmolStr) {
35 self.atoms.insert(key);
36 }
37
38 pub fn insert_key_value(&mut self, key: SmolStr, value: SmolStr) {
39 self.key_values.insert((key, value));
40 }
41
42 pub fn append(&mut self, other: &CfgOptions) {
43 for atom in &other.atoms {
44 self.atoms.insert(atom.clone());
45 }
46
47 for (key, value) in &other.key_values {
48 self.key_values.insert((key.clone(), value.clone()));
49 }
50 }
51}