bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir_def/src/db.rs')
-rw-r--r--crates/hir_def/src/db.rs39
1 files changed, 38 insertions, 1 deletions
diff --git a/crates/hir_def/src/db.rs b/crates/hir_def/src/db.rs
index 74bb7472d5..df6dcb024b 100644
--- a/crates/hir_def/src/db.rs
+++ b/crates/hir_def/src/db.rs
@@ -18,7 +18,7 @@ use crate::{
generics::GenericParams,
import_map::ImportMap,
intern::Interned,
- item_tree::ItemTree,
+ item_tree::{AttrOwner, ItemTree},
lang_item::{LangItemTarget, LangItems},
nameres::DefMap,
visibility::{self, Visibility},
@@ -184,6 +184,8 @@ pub trait DefDatabase: InternDatabase + AstDatabase + Upcast<dyn AstDatabase> {
#[salsa::transparent]
fn crate_limits(&self, crate_id: CrateId) -> CrateLimits;
+
+ fn crate_supports_no_std(&self, crate_id: CrateId) -> bool;
}
fn crate_def_map_wait(db: &dyn DefDatabase, krate: CrateId) -> Arc<DefMap> {
@@ -204,3 +206,38 @@ fn crate_limits(db: &dyn DefDatabase, crate_id: CrateId) -> CrateLimits {
recursion_limit: def_map.recursion_limit().unwrap_or(128),
}
}
+
+fn crate_supports_no_std(db: &dyn DefDatabase, crate_id: CrateId) -> bool {
+ let file = db.crate_graph()[crate_id].root_file_id;
+ let item_tree = db.file_item_tree(file.into());
+ let attrs = item_tree.raw_attrs(AttrOwner::TopLevel);
+ for attr in &**attrs {
+ match attr.path().as_ident().and_then(|id| id.as_text()) {
+ Some(ident) if ident == "no_std" => return true,
+ Some(ident) if ident == "cfg_attr" => {}
+ _ => continue,
+ }
+
+ // This is a `cfg_attr`; check if it could possibly expand to `no_std`.
+ // Syntax is: `#[cfg_attr(condition(cfg, style), attr0, attr1, <...>)]`
+ let tt = match attr.token_tree_value() {
+ Some(tt) => &tt.token_trees,
+ None => continue,
+ };
+
+ let segments = tt.split(|tt| match tt {
+ tt::TokenTree::Leaf(tt::Leaf::Punct(p)) if p.char == ',' => true,
+ _ => false,
+ });
+ for output in segments.skip(1) {
+ match output {
+ [tt::TokenTree::Leaf(tt::Leaf::Ident(ident))] if ident.text == "no_std" => {
+ return true
+ }
+ _ => {}
+ }
+ }
+ }
+
+ false
+}