From 7e78aebc8fbbb4043d62949681e4d700f1a2ec46 Mon Sep 17 00:00:00 2001
From: Jonas Schievink <jonasschievink@gmail.com>
Date: Fri, 9 Apr 2021 14:10:54 +0200
Subject: Rewrite `#[derive]` removal to be based on AST
---
crates/hir_expand/src/db.rs | 7 +--
crates/hir_expand/src/input.rs | 87 ++++++++++++++++++++++++++++++
crates/hir_expand/src/lib.rs | 1 +
crates/hir_expand/src/proc_macro.rs | 102 ------------------------------------
4 files changed, 92 insertions(+), 105 deletions(-)
create mode 100644 crates/hir_expand/src/input.rs
(limited to 'crates/hir_expand/src')
diff --git a/crates/hir_expand/src/db.rs b/crates/hir_expand/src/db.rs
index 10fe60821..95dc12744 100644
--- a/crates/hir_expand/src/db.rs
+++ b/crates/hir_expand/src/db.rs
@@ -14,9 +14,9 @@ use syntax::{
};
use crate::{
- ast_id_map::AstIdMap, hygiene::HygieneFrame, BuiltinDeriveExpander, BuiltinFnLikeExpander,
- EagerCallLoc, EagerMacroId, HirFileId, HirFileIdRepr, LazyMacroId, MacroCallId, MacroCallLoc,
- MacroDefId, MacroDefKind, MacroFile, ProcMacroExpander,
+ ast_id_map::AstIdMap, hygiene::HygieneFrame, input::process_macro_input, BuiltinDeriveExpander,
+ BuiltinFnLikeExpander, EagerCallLoc, EagerMacroId, HirFileId, HirFileIdRepr, LazyMacroId,
+ MacroCallId, MacroCallLoc, MacroDefId, MacroDefKind, MacroFile, ProcMacroExpander,
};
/// Total limit on the number of tokens produced by any macro invocation.
@@ -191,6 +191,7 @@ fn macro_arg_text(db: &dyn AstDatabase, id: MacroCallId) -> Option<GreenNode> {
};
let loc = db.lookup_intern_macro(id);
let arg = loc.kind.arg(db)?;
+ let arg = process_macro_input(db, arg, id);
Some(arg.green())
}
diff --git a/crates/hir_expand/src/input.rs b/crates/hir_expand/src/input.rs
new file mode 100644
index 000000000..8f652cd7c
--- /dev/null
+++ b/crates/hir_expand/src/input.rs
@@ -0,0 +1,87 @@
+//! Macro input conditioning.
+
+use syntax::{
+ ast::{self, AttrsOwner},
+ AstNode, SyntaxNode,
+};
+
+use crate::{db::AstDatabase, name::AsName, AttrId, LazyMacroId, MacroCallKind, MacroCallLoc};
+
+pub fn process_macro_input(db: &dyn AstDatabase, node: SyntaxNode, id: LazyMacroId) -> SyntaxNode {
+ let loc: MacroCallLoc = db.lookup_intern_macro(id);
+
+ match loc.kind {
+ MacroCallKind::FnLike { .. } => node,
+ MacroCallKind::Derive { derive_attr, .. } => {
+ let item = match ast::Item::cast(node.clone()) {
+ Some(item) => item,
+ None => return node,
+ };
+
+ remove_derives_up_to(item, derive_attr).syntax().clone()
+ }
+ }
+}
+
+/// Removes `#[derive]` attributes from `item`, up to `attr`.
+fn remove_derives_up_to(item: ast::Item, attr: AttrId) -> ast::Item {
+ let item = item.clone_for_update();
+ let idx = attr.0 as usize;
+ for attr in item.attrs().take(idx + 1) {
+ if let Some(name) =
+ attr.path().and_then(|path| path.as_single_segment()).and_then(|seg| seg.name_ref())
+ {
+ if name.as_name().to_string() == "derive" {
+ attr.syntax().detach();
+ }
+ }
+ }
+ item
+}
+
+#[cfg(test)]
+mod tests {
+ use base_db::fixture::WithFixture;
+ use base_db::SourceDatabase;
+ use expect_test::{expect, Expect};
+
+ use crate::test_db::TestDB;
+
+ use super::*;
+
+ fn test_remove_derives_up_to(attr: AttrId, ra_fixture: &str, expect: Expect) {
+ let (db, file_id) = TestDB::with_single_file(&ra_fixture);
+ let parsed = db.parse(file_id);
+
+ let mut items: Vec<_> =
+ parsed.syntax_node().descendants().filter_map(ast::Item::cast).collect();
+ assert_eq!(items.len(), 1);
+
+ let item = remove_derives_up_to(items.pop().unwrap(), attr);
+ expect.assert_eq(&item.to_string());
+ }
+
+ #[test]
+ fn remove_derive() {
+ test_remove_derives_up_to(
+ AttrId(2),
+ r#"
+#[allow(unused)]
+#[derive(Copy)]
+#[derive(Hello)]
+#[derive(Clone)]
+struct A {
+ bar: u32
+}
+ "#,
+ expect![[r#"
+#[allow(unused)]
+
+
+#[derive(Clone)]
+struct A {
+ bar: u32
+}"#]],
+ );
+ }
+}
diff --git a/crates/hir_expand/src/lib.rs b/crates/hir_expand/src/lib.rs
index a0e6aec62..7349fdfe4 100644
--- a/crates/hir_expand/src/lib.rs
+++ b/crates/hir_expand/src/lib.rs
@@ -14,6 +14,7 @@ pub mod builtin_macro;
pub mod proc_macro;
pub mod quote;
pub mod eager;
+mod input;
use either::Either;
pub use mbe::{ExpandError, ExpandResult};
diff --git a/crates/hir_expand/src/proc_macro.rs b/crates/hir_expand/src/proc_macro.rs
index 75e950816..d5643393a 100644
--- a/crates/hir_expand/src/proc_macro.rs
+++ b/crates/hir_expand/src/proc_macro.rs
@@ -2,7 +2,6 @@
use crate::db::AstDatabase;
use base_db::{CrateId, ProcMacroId};
-use tt::buffer::{Cursor, TokenBuffer};
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
pub struct ProcMacroExpander {
@@ -44,9 +43,6 @@ impl ProcMacroExpander {
.clone()
.ok_or_else(|| err!("No derive macro found."))?;
- let tt = remove_derive_attrs(tt)
- .ok_or_else(|| err!("Fail to remove derive for custom derive"))?;
-
// Proc macros have access to the environment variables of the invoking crate.
let env = &krate_graph[calling_crate].env;
@@ -56,101 +52,3 @@ impl ProcMacroExpander {
}
}
}
-
-fn eat_punct(cursor: &mut Cursor, c: char) -> bool {
- if let Some(tt::buffer::TokenTreeRef::Leaf(tt::Leaf::Punct(punct), _)) = cursor.token_tree() {
- if punct.char == c {
- *cursor = cursor.bump();
- return true;
- }
- }
- false
-}
-
-fn eat_subtree(cursor: &mut Cursor, kind: tt::DelimiterKind) -> bool {
- if let Some(tt::buffer::TokenTreeRef::Subtree(subtree, _)) = cursor.token_tree() {
- if Some(kind) == subtree.delimiter_kind() {
- *cursor = cursor.bump_subtree();
- return true;
- }
- }
- false
-}
-
-fn eat_ident(cursor: &mut Cursor, t: &str) -> bool {
- if let Some(tt::buffer::TokenTreeRef::Leaf(tt::Leaf::Ident(ident), _)) = cursor.token_tree() {
- if t == ident.text.as_str() {
- *cursor = cursor.bump();
- return true;
- }
- }
- false
-}
-
-fn remove_derive_attrs(tt: &tt::Subtree) -> Option<tt::Subtree> {
- let buffer = TokenBuffer::from_tokens(&tt.token_trees);
- let mut p = buffer.begin();
- let mut result = tt::Subtree::default();
-
- while !p.eof() {
- let curr = p;
-
- if eat_punct(&mut p, '#') {
- eat_punct(&mut p, '!');
- let parent = p;
- if eat_subtree(&mut p, tt::DelimiterKind::Bracket) {
- if eat_ident(&mut p, "derive") {
- p = parent.bump();
- continue;
- }
- }
- }
-
- result.token_trees.push(curr.token_tree()?.cloned());
- p = curr.bump();
- }
-
- Some(result)
-}
-
-#[cfg(test)]
-mod tests {
- use super::*;
- use test_utils::assert_eq_text;
-
- #[test]
- fn test_remove_derive_attrs() {
- let tt = mbe::parse_to_token_tree(
- r#"
- #[allow(unused)]
- #[derive(Copy)]
- #[derive(Hello)]
- struct A {
- bar: u32
- }
-"#,
- )
- .unwrap()
- .0;
- let result = format!("{:#?}", remove_derive_attrs(&tt).unwrap());
-
- assert_eq_text!(
- r#"
-SUBTREE $
- PUNCH # [alone] 0
- SUBTREE [] 1
- IDENT allow 2
- SUBTREE () 3
- IDENT unused 4
- IDENT struct 15
- IDENT A 16
- SUBTREE {} 17
- IDENT bar 18
- PUNCH : [alone] 19
- IDENT u32 20
-"#
- .trim(),
- &result
- );
- }
-}
--
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