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.rs | 216 |
1 files changed, 216 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..983aa1dfd5 --- /dev/null +++ b/crates/ide/src/inlay_hints/adjustment.rs @@ -0,0 +1,216 @@ +//! Implementation of "adjustment" inlay hints: +//! ```no_run +//! let _: u32 = /* <never-to-any> */ loop {}; +//! let _: &u32 = /* &* */ &mut 0; +//! ``` +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(()) +} + +#[cfg(test)] +mod tests { + use crate::{ + inlay_hints::tests::{check_with_config, DISABLED_CONFIG}, + AdjustmentHints, InlayHintsConfig, + }; + + #[test] + fn adjustment_hints() { + check_with_config( + InlayHintsConfig { adjustment_hints: AdjustmentHints::Always, ..DISABLED_CONFIG }, + r#" +//- minicore: coerce_unsized +fn main() { + let _: u32 = loop {}; + //^^^^^^^<never-to-any> + let _: &u32 = &mut 0; + //^^^^^^& + //^^^^^^* + let _: &mut u32 = &mut 0; + //^^^^^^&mut $ + //^^^^^^* + let _: *const u32 = &mut 0; + //^^^^^^&raw const $ + //^^^^^^* + let _: *mut u32 = &mut 0; + //^^^^^^&raw mut $ + //^^^^^^* + let _: fn() = main; + //^^^^<fn-item-to-fn-pointer> + let _: unsafe fn() = main; + //^^^^<safe-fn-pointer-to-unsafe-fn-pointer> + //^^^^<fn-item-to-fn-pointer> + let _: unsafe fn() = main as fn(); + //^^^^^^^^^^^^<safe-fn-pointer-to-unsafe-fn-pointer> + let _: fn() = || {}; + //^^^^^<closure-to-fn-pointer> + let _: unsafe fn() = || {}; + //^^^^^<closure-to-unsafe-fn-pointer> + let _: *const u32 = &mut 0u32 as *mut u32; + //^^^^^^^^^^^^^^^^^^^^^<mut-ptr-to-const-ptr> + let _: &mut [_] = &mut [0; 0]; + //^^^^^^^^^^^<unsize> + //^^^^^^^^^^^&mut $ + //^^^^^^^^^^^* + + Struct.consume(); + Struct.by_ref(); + //^^^^^^( + //^^^^^^& + //^^^^^^) + Struct.by_ref_mut(); + //^^^^^^( + //^^^^^^&mut $ + //^^^^^^) + + (&Struct).consume(); + //^^^^^^^* + (&Struct).by_ref(); + + (&mut Struct).consume(); + //^^^^^^^^^^^* + (&mut Struct).by_ref(); + //^^^^^^^^^^^& + //^^^^^^^^^^^* + (&mut Struct).by_ref_mut(); + + // Check that block-like expressions don't duplicate hints + let _: &mut [u32] = (&mut []); + //^^^^^^^<unsize> + //^^^^^^^&mut $ + //^^^^^^^* + let _: &mut [u32] = { &mut [] }; + //^^^^^^^<unsize> + //^^^^^^^&mut $ + //^^^^^^^* + let _: &mut [u32] = unsafe { &mut [] }; + //^^^^^^^<unsize> + //^^^^^^^&mut $ + //^^^^^^^* + let _: &mut [u32] = if true { + &mut [] + //^^^^^^^<unsize> + //^^^^^^^&mut $ + //^^^^^^^* + } else { + loop {} + //^^^^^^^<never-to-any> + }; + let _: &mut [u32] = match () { () => &mut [] } + //^^^^^^^<unsize> + //^^^^^^^&mut $ + //^^^^^^^* +} + +#[derive(Copy, Clone)] +struct Struct; +impl Struct { + fn consume(self) {} + fn by_ref(&self) {} + fn by_ref_mut(&mut self) {} +} +trait Trait {} +impl Trait for Struct {} +"#, + ) + } +} |