From b1ed887d813bf5775a16624694939fdf836f97b1 Mon Sep 17 00:00:00 2001 From: uHOOCCOOHu Date: Mon, 30 Sep 2019 06:52:15 +0800 Subject: Introduce ra_cfg to parse and evaluate CfgExpr --- crates/ra_cfg/src/cfg_expr.rs | 128 ++++++++++++++++++++++++++++++++++++++++++ crates/ra_cfg/src/lib.rs | 43 ++++++++++++++ 2 files changed, 171 insertions(+) create mode 100644 crates/ra_cfg/src/cfg_expr.rs create mode 100644 crates/ra_cfg/src/lib.rs (limited to 'crates/ra_cfg/src') diff --git a/crates/ra_cfg/src/cfg_expr.rs b/crates/ra_cfg/src/cfg_expr.rs new file mode 100644 index 000000000..efeadf462 --- /dev/null +++ b/crates/ra_cfg/src/cfg_expr.rs @@ -0,0 +1,128 @@ +use std::slice::Iter as SliceIter; + +use ra_syntax::SmolStr; +use tt::{Leaf, Subtree, TokenTree}; + +#[derive(Debug, Clone, PartialEq, Eq)] +pub enum CfgExpr { + Invalid, + Atom(SmolStr), + KeyValue { key: SmolStr, value: SmolStr }, + All(Vec), + Any(Vec), + Not(Box), +} + +impl CfgExpr { + /// Fold the cfg by querying all basic `Atom` and `KeyValue` predicates. + pub fn fold(&self, query: &impl 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), + } + } +} + +pub fn parse_cfg(tt: &Subtree) -> CfgExpr { + next_cfg_expr(&mut tt.token_trees.iter()).unwrap_or(CfgExpr::Invalid) +} + +fn next_cfg_expr(it: &mut SliceIter) -> Option { + let name = match it.next() { + None => return None, + Some(TokenTree::Leaf(Leaf::Ident(ident))) => ident.text.clone(), + Some(_) => return Some(CfgExpr::Invalid), + }; + + // Peek + let ret = match it.as_slice().first() { + Some(TokenTree::Leaf(Leaf::Punct(punct))) if punct.char == '=' => { + match it.as_slice().get(1) { + Some(TokenTree::Leaf(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(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(TokenTree::Leaf(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 ra_syntax::ast::{self, AstNode}; + + fn assert_parse_result(input: &str, expected: CfgExpr) { + let source_file = ast::SourceFile::parse(input).ok().unwrap(); + let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap(); + let (tt, _) = ast_to_token_tree(&tt).unwrap(); + assert_eq!(parse_cfg(&tt), 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/ra_cfg/src/lib.rs b/crates/ra_cfg/src/lib.rs new file mode 100644 index 000000000..fa5822d8a --- /dev/null +++ b/crates/ra_cfg/src/lib.rs @@ -0,0 +1,43 @@ +//! ra_cfg defines conditional compiling options, `cfg` attibute parser and evaluator +use ra_syntax::SmolStr; +use rustc_hash::{FxHashMap, FxHashSet}; + +mod cfg_expr; + +pub use cfg_expr::{parse_cfg, CfgExpr}; + +#[derive(Debug, Clone, PartialEq, Eq, Default)] +pub struct CfgOptions { + atoms: FxHashSet, + features: FxHashSet, + options: FxHashMap, +} + +impl CfgOptions { + pub fn check(&self, cfg: &CfgExpr) -> Option { + cfg.fold(&|key, value| match value { + None => self.atoms.contains(key), + Some(value) if key == "feature" => self.features.contains(value), + Some(value) => self.options.get(key).map_or(false, |v| v == value), + }) + } + + pub fn is_cfg_enabled(&self, attr: &tt::Subtree) -> Option { + self.check(&parse_cfg(attr)) + } + + pub fn atom(mut self, name: SmolStr) -> CfgOptions { + self.atoms.insert(name); + self + } + + pub fn feature(mut self, name: SmolStr) -> CfgOptions { + self.features.insert(name); + self + } + + pub fn option(mut self, key: SmolStr, value: SmolStr) -> CfgOptions { + self.options.insert(key, value); + self + } +} -- cgit v1.2.3