From 68c223872562a8d746d4f1045d508887a0cbca5e Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Thu, 13 Aug 2020 10:19:09 +0200 Subject: Rename ra_cfg -> cfg --- crates/cfg/src/cfg_expr.rs | 133 +++++++++++++++++++++++++++++++++++++++++++++ crates/cfg/src/lib.rs | 51 +++++++++++++++++ 2 files changed, 184 insertions(+) create mode 100644 crates/cfg/src/cfg_expr.rs create mode 100644 crates/cfg/src/lib.rs (limited to 'crates/cfg/src') 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 @@ +//! The condition expression used in `#[cfg(..)]` attributes. +//! +//! See: https://doc.rust-lang.org/reference/conditional-compilation.html#conditional-compilation + +use std::slice::Iter as SliceIter; + +use tt::SmolStr; + +#[derive(Debug, Clone, PartialEq, Eq)] +pub enum CfgExpr { + Invalid, + Atom(SmolStr), + KeyValue { key: SmolStr, value: SmolStr }, + All(Vec), + Any(Vec), + Not(Box), +} + +impl CfgExpr { + pub fn parse(tt: &tt::Subtree) -> CfgExpr { + next_cfg_expr(&mut tt.token_trees.iter()).unwrap_or(CfgExpr::Invalid) + } + /// Fold the cfg by querying all basic `Atom` and `KeyValue` predicates. + pub fn fold(&self, query: &dyn Fn(&SmolStr, Option<&SmolStr>) -> bool) -> Option { + match self { + CfgExpr::Invalid => None, + CfgExpr::Atom(name) => Some(query(name, None)), + CfgExpr::KeyValue { key, value } => Some(query(key, Some(value))), + CfgExpr::All(preds) => { + preds.iter().try_fold(true, |s, pred| Some(s && pred.fold(query)?)) + } + CfgExpr::Any(preds) => { + preds.iter().try_fold(false, |s, pred| Some(s || pred.fold(query)?)) + } + CfgExpr::Not(pred) => pred.fold(query).map(|s| !s), + } + } +} + +fn next_cfg_expr(it: &mut SliceIter) -> Option { + let name = match it.next() { + None => return None, + Some(tt::TokenTree::Leaf(tt::Leaf::Ident(ident))) => ident.text.clone(), + Some(_) => return Some(CfgExpr::Invalid), + }; + + // Peek + let ret = match it.as_slice().first() { + Some(tt::TokenTree::Leaf(tt::Leaf::Punct(punct))) if punct.char == '=' => { + match it.as_slice().get(1) { + Some(tt::TokenTree::Leaf(tt::Leaf::Literal(literal))) => { + it.next(); + it.next(); + // FIXME: escape? raw string? + let value = + SmolStr::new(literal.text.trim_start_matches('"').trim_end_matches('"')); + CfgExpr::KeyValue { key: name, value } + } + _ => return Some(CfgExpr::Invalid), + } + } + Some(tt::TokenTree::Subtree(subtree)) => { + it.next(); + let mut sub_it = subtree.token_trees.iter(); + let mut subs = std::iter::from_fn(|| next_cfg_expr(&mut sub_it)).collect(); + match name.as_str() { + "all" => CfgExpr::All(subs), + "any" => CfgExpr::Any(subs), + "not" => CfgExpr::Not(Box::new(subs.pop().unwrap_or(CfgExpr::Invalid))), + _ => CfgExpr::Invalid, + } + } + _ => CfgExpr::Atom(name), + }; + + // Eat comma separator + if let Some(tt::TokenTree::Leaf(tt::Leaf::Punct(punct))) = it.as_slice().first() { + if punct.char == ',' { + it.next(); + } + } + Some(ret) +} + +#[cfg(test)] +mod tests { + use super::*; + + use mbe::ast_to_token_tree; + use syntax::ast::{self, AstNode}; + + fn assert_parse_result(input: &str, expected: CfgExpr) { + let (tt, _) = { + let source_file = ast::SourceFile::parse(input).ok().unwrap(); + let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap(); + ast_to_token_tree(&tt).unwrap() + }; + let cfg = CfgExpr::parse(&tt); + assert_eq!(cfg, expected); + } + + #[test] + fn test_cfg_expr_parser() { + assert_parse_result("#![cfg(foo)]", CfgExpr::Atom("foo".into())); + assert_parse_result("#![cfg(foo,)]", CfgExpr::Atom("foo".into())); + assert_parse_result( + "#![cfg(not(foo))]", + CfgExpr::Not(Box::new(CfgExpr::Atom("foo".into()))), + ); + assert_parse_result("#![cfg(foo(bar))]", CfgExpr::Invalid); + + // Only take the first + assert_parse_result(r#"#![cfg(foo, bar = "baz")]"#, CfgExpr::Atom("foo".into())); + + assert_parse_result( + r#"#![cfg(all(foo, bar = "baz"))]"#, + CfgExpr::All(vec![ + CfgExpr::Atom("foo".into()), + CfgExpr::KeyValue { key: "bar".into(), value: "baz".into() }, + ]), + ); + + assert_parse_result( + r#"#![cfg(any(not(), all(), , bar = "baz",))]"#, + CfgExpr::Any(vec![ + CfgExpr::Not(Box::new(CfgExpr::Invalid)), + CfgExpr::All(vec![]), + CfgExpr::Invalid, + CfgExpr::KeyValue { key: "bar".into(), value: "baz".into() }, + ]), + ); + } +} 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 @@ +//! cfg defines conditional compiling options, `cfg` attibute parser and evaluator + +mod cfg_expr; + +use rustc_hash::FxHashSet; +use tt::SmolStr; + +pub use cfg_expr::CfgExpr; + +/// Configuration options used for conditional compilition on items with `cfg` attributes. +/// We have two kind of options in different namespaces: atomic options like `unix`, and +/// key-value options like `target_arch="x86"`. +/// +/// Note that for key-value options, one key can have multiple values (but not none). +/// `feature` is an example. We have both `feature="foo"` and `feature="bar"` if features +/// `foo` and `bar` are both enabled. And here, we store key-value options as a set of tuple +/// of key and value in `key_values`. +/// +/// See: https://doc.rust-lang.org/reference/conditional-compilation.html#set-configuration-options +#[derive(Debug, Clone, PartialEq, Eq, Default)] +pub struct CfgOptions { + atoms: FxHashSet, + key_values: FxHashSet<(SmolStr, SmolStr)>, +} + +impl CfgOptions { + pub fn check(&self, cfg: &CfgExpr) -> Option { + cfg.fold(&|key, value| match value { + None => self.atoms.contains(key), + Some(value) => self.key_values.contains(&(key.clone(), value.clone())), + }) + } + + pub fn insert_atom(&mut self, key: SmolStr) { + self.atoms.insert(key); + } + + pub fn insert_key_value(&mut self, key: SmolStr, value: SmolStr) { + self.key_values.insert((key, value)); + } + + pub fn append(&mut self, other: &CfgOptions) { + for atom in &other.atoms { + self.atoms.insert(atom.clone()); + } + + for (key, value) in &other.key_values { + self.key_values.insert((key.clone(), value.clone())); + } + } +} -- cgit v1.2.3