bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide/src/inlay_hints/adjustment.rs')
-rw-r--r--crates/ide/src/inlay_hints/adjustment.rs102
1 files changed, 102 insertions, 0 deletions
diff --git a/crates/ide/src/inlay_hints/adjustment.rs b/crates/ide/src/inlay_hints/adjustment.rs
new file mode 100644
index 0000000000..3fa2ed3307
--- /dev/null
+++ b/crates/ide/src/inlay_hints/adjustment.rs
@@ -0,0 +1,102 @@
+use hir::{Adjust, AutoBorrow, Mutability, OverloadedDeref, PointerCast, Safety, Semantics};
+use ide_db::RootDatabase;
+
+use syntax::ast::{self, AstNode};
+
+use crate::{AdjustmentHints, InlayHint, InlayHintsConfig, InlayKind};
+
+pub(super) fn hints(
+ acc: &mut Vec<InlayHint>,
+ sema: &Semantics<'_, RootDatabase>,
+ config: &InlayHintsConfig,
+ expr: &ast::Expr,
+) -> Option<()> {
+ if config.adjustment_hints == AdjustmentHints::Never {
+ return None;
+ }
+
+ // These inherit from the inner expression which would result in duplicate hints
+ if let ast::Expr::ParenExpr(_)
+ | ast::Expr::IfExpr(_)
+ | ast::Expr::BlockExpr(_)
+ | ast::Expr::MatchExpr(_) = expr
+ {
+ return None;
+ }
+
+ let parent = expr.syntax().parent().and_then(ast::Expr::cast);
+ let descended = sema.descend_node_into_attributes(expr.clone()).pop();
+ let desc_expr = descended.as_ref().unwrap_or(expr);
+ let adjustments = sema.expr_adjustments(desc_expr).filter(|it| !it.is_empty())?;
+ let needs_parens = match parent {
+ Some(parent) => {
+ match parent {
+ ast::Expr::AwaitExpr(_)
+ | ast::Expr::CallExpr(_)
+ | ast::Expr::CastExpr(_)
+ | ast::Expr::FieldExpr(_)
+ | ast::Expr::MethodCallExpr(_)
+ | ast::Expr::TryExpr(_) => true,
+ // FIXME: shorthands need special casing, though not sure if adjustments are even valid there
+ ast::Expr::RecordExpr(_) => false,
+ ast::Expr::IndexExpr(index) => index.base().as_ref() == Some(expr),
+ _ => false,
+ }
+ }
+ None => false,
+ };
+ if needs_parens {
+ acc.push(InlayHint {
+ range: expr.syntax().text_range(),
+ kind: InlayKind::OpeningParenthesis,
+ label: "(".into(),
+ tooltip: None,
+ });
+ }
+ for adjustment in adjustments.into_iter().rev() {
+ // FIXME: Add some nicer tooltips to each of these
+ let text = match adjustment {
+ Adjust::NeverToAny if config.adjustment_hints == AdjustmentHints::Always => {
+ "<never-to-any>"
+ }
+ Adjust::Deref(None) => "*",
+ Adjust::Deref(Some(OverloadedDeref(Mutability::Mut))) => "*",
+ Adjust::Deref(Some(OverloadedDeref(Mutability::Shared))) => "*",
+ Adjust::Borrow(AutoBorrow::Ref(Mutability::Shared)) => "&",
+ Adjust::Borrow(AutoBorrow::Ref(Mutability::Mut)) => "&mut ",
+ Adjust::Borrow(AutoBorrow::RawPtr(Mutability::Shared)) => "&raw const ",
+ Adjust::Borrow(AutoBorrow::RawPtr(Mutability::Mut)) => "&raw mut ",
+ // some of these could be represented via `as` casts, but that's not too nice and
+ // handling everything as a prefix expr makes the `(` and `)` insertion easier
+ Adjust::Pointer(cast) if config.adjustment_hints == AdjustmentHints::Always => {
+ match cast {
+ PointerCast::ReifyFnPointer => "<fn-item-to-fn-pointer>",
+ PointerCast::UnsafeFnPointer => "<safe-fn-pointer-to-unsafe-fn-pointer>",
+ PointerCast::ClosureFnPointer(Safety::Unsafe) => {
+ "<closure-to-unsafe-fn-pointer>"
+ }
+ PointerCast::ClosureFnPointer(Safety::Safe) => "<closure-to-fn-pointer>",
+ PointerCast::MutToConstPointer => "<mut-ptr-to-const-ptr>",
+ PointerCast::ArrayToPointer => "<array-ptr-to-element-ptr>",
+ PointerCast::Unsize => "<unsize>",
+ }
+ }
+ _ => continue,
+ };
+ acc.push(InlayHint {
+ range: expr.syntax().text_range(),
+ kind: InlayKind::AdjustmentHint,
+ label: text.into(),
+ tooltip: None,
+ });
+ }
+ if needs_parens {
+ acc.push(InlayHint {
+ range: expr.syntax().text_range(),
+ kind: InlayKind::ClosingParenthesis,
+ label: ")".into(),
+ tooltip: None,
+ });
+ }
+ Some(())
+}