Merge #4233

4233: Remove dead TryBlock expressio r=matklad a=matklad

bors r+
🤖

Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>

crates/ra_hir_def/src/body/lower.rs

@@ -182,10 +182,6 @@ impl ExprCollector<'_> {
 
                 self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
             }
-            ast::Expr::TryBlockExpr(e) => {
-                let body = self.collect_block_opt(e.body());
-                self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
-            }
             ast::Expr::BlockExpr(e) => self.collect_block(e),
             ast::Expr::LoopExpr(e) => {
                 let body = self.collect_block_opt(e.loop_body());

crates/ra_hir_def/src/expr.rs

@@ -101,9 +101,6 @@ pub enum Expr {
     Try {
         expr: ExprId,
     },
-    TryBlock {
-        body: ExprId,
-    },
     Cast {
         expr: ExprId,
         type_ref: TypeRef,
@@ -239,7 +236,6 @@ impl Expr {
                     f(*expr);
                 }
             }
-            Expr::TryBlock { body } => f(*body),
             Expr::Loop { body } => f(*body),
             Expr::While { condition, body } => {
                 f(*condition);

crates/ra_hir_ty/src/infer/expr.rs

@@ -73,11 +73,6 @@ impl<'a> InferenceContext<'a> {
                 self.coerce_merge_branch(&then_ty, &else_ty)
             }
             Expr::Block { statements, tail } => self.infer_block(statements, *tail, expected),
-            Expr::TryBlock { body } => {
-                let _inner = self.infer_expr(*body, expected);
-                // FIXME should be std::result::Result<{inner}, _>
-                Ty::Unknown
-            }
             Expr::Loop { body } => {
                 self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
                 // FIXME handle break with value

crates/ra_parser/src/grammar/expressions/atom.rs

@@ -84,7 +84,7 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMar
         T![box] => box_expr(p, None),
         T![for] => for_expr(p, None),
         T![while] => while_expr(p, None),
-        T![try] => try_block_expr(p, None),
+        T![try] => try_expr(p, None),
         LIFETIME if la == T![:] => {
             let m = p.start();
             label(p);
@@ -134,7 +134,7 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMar
         }
     };
     let blocklike = match done.kind() {
-        IF_EXPR | WHILE_EXPR | FOR_EXPR | LOOP_EXPR | MATCH_EXPR | BLOCK_EXPR | TRY_BLOCK_EXPR => {
+        IF_EXPR | WHILE_EXPR | FOR_EXPR | LOOP_EXPR | MATCH_EXPR | BLOCK_EXPR | TRY_EXPR => {
             BlockLike::Block
         }
         _ => BlockLike::NotBlock,
@@ -532,7 +532,7 @@ fn break_expr(p: &mut Parser, r: Restrictions) -> CompletedMarker {
 // fn foo() {
 //     let _ = try {};
 // }
-fn try_block_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
+fn try_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
     assert!(p.at(T![try]));
     let m = m.unwrap_or_else(|| p.start());
     // Special-case `try!` as macro.

crates/ra_parser/src/syntax_kind/generated.rs

@@ -191,7 +191,6 @@ pub enum SyntaxKind {
     RECORD_LIT,
     RECORD_FIELD_LIST,
     RECORD_FIELD,
-    TRY_BLOCK_EXPR,
     BOX_EXPR,
     CALL_EXPR,
     INDEX_EXPR,

crates/ra_syntax/src/ast.rs

@@ -16,7 +16,9 @@ use crate::{
 };
 
 pub use self::{
-    expr_extensions::{ArrayExprKind, BinOp, ElseBranch, LiteralKind, PrefixOp, RangeOp},
+    expr_extensions::{
+        ArrayExprKind, BinOp, BlockModifier, ElseBranch, LiteralKind, PrefixOp, RangeOp,
+    },
     extensions::{
         AttrKind, FieldKind, NameOrNameRef, PathSegmentKind, SelfParamKind, SlicePatComponents,
         StructKind, TypeBoundKind, VisibilityKind,

crates/ra_syntax/src/ast/expr_extensions.rs

@@ -16,7 +16,7 @@ impl ast::Expr {
             | ast::Expr::WhileExpr(_)
             | ast::Expr::BlockExpr(_)
             | ast::Expr::MatchExpr(_)
-            | ast::Expr::TryBlockExpr(_) => true,
+            | ast::Expr::TryExpr(_) => true,
             _ => false,
         }
     }
@@ -359,7 +359,22 @@ impl ast::Literal {
     }
 }
 
+pub enum BlockModifier {
+    Async(SyntaxToken),
+    Unsafe(SyntaxToken),
+}
+
 impl ast::BlockExpr {
+    pub fn modifier(&self) -> Option<BlockModifier> {
+        if let Some(token) = self.async_token() {
+            return Some(BlockModifier::Async(token));
+        }
+        if let Some(token) = self.unsafe_token() {
+            return Some(BlockModifier::Unsafe(token));
+        }
+        None
+    }
+
     /// false if the block is an intrinsic part of the syntax and can't be
     /// replaced with arbitrary expression.
     ///
@@ -368,15 +383,15 @@ impl ast::BlockExpr {
     /// const FOO: () = { stand_alone };
     /// ```
     pub fn is_standalone(&self) -> bool {
-        if self.unsafe_token().is_some() || self.async_token().is_some() {
+        if self.modifier().is_some() {
             return false;
         }
-        let kind = match self.syntax().parent() {
+        let parent = match self.syntax().parent() {
+            Some(it) => it,
             None => return true,
-            Some(it) => it.kind(),
         };
-        match kind {
+        match parent.kind() {
-            FN_DEF | IF_EXPR | WHILE_EXPR | LOOP_EXPR | TRY_BLOCK_EXPR => false,
+            FN_DEF | IF_EXPR | WHILE_EXPR | LOOP_EXPR => false,
             _ => true,
         }
     }

crates/ra_syntax/src/ast/generated/nodes.rs

@@ -475,16 +475,6 @@ impl LoopExpr {
     pub fn loop_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![loop]) }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct TryBlockExpr {
-    pub(crate) syntax: SyntaxNode,
-}
-impl ast::AttrsOwner for TryBlockExpr {}
-impl TryBlockExpr {
-    pub fn try_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![try]) }
-    pub fn body(&self) -> Option<BlockExpr> { support::child(&self.syntax) }
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct ForExpr {
     pub(crate) syntax: SyntaxNode,
@@ -1475,7 +1465,6 @@ pub enum Expr {
     FieldExpr(FieldExpr),
     AwaitExpr(AwaitExpr),
     TryExpr(TryExpr),
-    TryBlockExpr(TryBlockExpr),
     CastExpr(CastExpr),
     RefExpr(RefExpr),
     PrefixExpr(PrefixExpr),
@@ -1958,17 +1947,6 @@ impl AstNode for LoopExpr {
     }
     fn syntax(&self) -> &SyntaxNode { &self.syntax }
 }
-impl AstNode for TryBlockExpr {
-    fn can_cast(kind: SyntaxKind) -> bool { kind == TRY_BLOCK_EXPR }
-    fn cast(syntax: SyntaxNode) -> Option<Self> {
-        if Self::can_cast(syntax.kind()) {
-            Some(Self { syntax })
-        } else {
-            None
-        }
-    }
-    fn syntax(&self) -> &SyntaxNode { &self.syntax }
-}
 impl AstNode for ForExpr {
     fn can_cast(kind: SyntaxKind) -> bool { kind == FOR_EXPR }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
@@ -3310,9 +3288,6 @@ impl From<AwaitExpr> for Expr {
 impl From<TryExpr> for Expr {
     fn from(node: TryExpr) -> Expr { Expr::TryExpr(node) }
 }
-impl From<TryBlockExpr> for Expr {
-    fn from(node: TryBlockExpr) -> Expr { Expr::TryBlockExpr(node) }
-}
 impl From<CastExpr> for Expr {
     fn from(node: CastExpr) -> Expr { Expr::CastExpr(node) }
 }
@@ -3343,9 +3318,8 @@ impl AstNode for Expr {
             TUPLE_EXPR | ARRAY_EXPR | PAREN_EXPR | PATH_EXPR | LAMBDA_EXPR | IF_EXPR
             | LOOP_EXPR | FOR_EXPR | WHILE_EXPR | CONTINUE_EXPR | BREAK_EXPR | LABEL
             | BLOCK_EXPR | RETURN_EXPR | MATCH_EXPR | RECORD_LIT | CALL_EXPR | INDEX_EXPR
-            | METHOD_CALL_EXPR | FIELD_EXPR | AWAIT_EXPR | TRY_EXPR | TRY_BLOCK_EXPR
+            | METHOD_CALL_EXPR | FIELD_EXPR | AWAIT_EXPR | TRY_EXPR | CAST_EXPR | REF_EXPR
-            | CAST_EXPR | REF_EXPR | PREFIX_EXPR | RANGE_EXPR | BIN_EXPR | LITERAL | MACRO_CALL
+            | PREFIX_EXPR | RANGE_EXPR | BIN_EXPR | LITERAL | MACRO_CALL | BOX_EXPR => true,
-            | BOX_EXPR => true,
             _ => false,
         }
     }
@@ -3373,7 +3347,6 @@ impl AstNode for Expr {
             FIELD_EXPR => Expr::FieldExpr(FieldExpr { syntax }),
             AWAIT_EXPR => Expr::AwaitExpr(AwaitExpr { syntax }),
             TRY_EXPR => Expr::TryExpr(TryExpr { syntax }),
-            TRY_BLOCK_EXPR => Expr::TryBlockExpr(TryBlockExpr { syntax }),
             CAST_EXPR => Expr::CastExpr(CastExpr { syntax }),
             REF_EXPR => Expr::RefExpr(RefExpr { syntax }),
             PREFIX_EXPR => Expr::PrefixExpr(PrefixExpr { syntax }),
@@ -3410,7 +3383,6 @@ impl AstNode for Expr {
             Expr::FieldExpr(it) => &it.syntax,
             Expr::AwaitExpr(it) => &it.syntax,
             Expr::TryExpr(it) => &it.syntax,
-            Expr::TryBlockExpr(it) => &it.syntax,
             Expr::CastExpr(it) => &it.syntax,
             Expr::RefExpr(it) => &it.syntax,
             Expr::PrefixExpr(it) => &it.syntax,
@@ -3891,11 +3863,6 @@ impl std::fmt::Display for LoopExpr {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
-impl std::fmt::Display for TryBlockExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        std::fmt::Display::fmt(self.syntax(), f)
-    }
-}
 impl std::fmt::Display for ForExpr {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)

xtask/src/ast_src.rs

@@ -162,7 +162,6 @@ pub(crate) const KINDS_SRC: KindsSrc = KindsSrc {
         "RECORD_LIT",
         "RECORD_FIELD_LIST",
         "RECORD_FIELD",
-        "TRY_BLOCK_EXPR",
         "BOX_EXPR",
         // postfix
         "CALL_EXPR",
@@ -440,7 +439,6 @@ pub(crate) const AST_SRC: AstSrc = AstSrc {
         }
         struct IfExpr: AttrsOwner { T![if], Condition }
         struct LoopExpr: AttrsOwner, LoopBodyOwner { T![loop] }
-        struct TryBlockExpr: AttrsOwner { T![try], body: BlockExpr }
         struct ForExpr: AttrsOwner, LoopBodyOwner {
             T![for],
             Pat,
@@ -722,7 +720,6 @@ pub(crate) const AST_SRC: AstSrc = AstSrc {
             FieldExpr,
             AwaitExpr,
             TryExpr,
-            TryBlockExpr,
             CastExpr,
             RefExpr,
             PrefixExpr,