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Merged
merged 1 commit into from
Feb 14, 2024
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feature: Add basic support for become expr/tail calls #15003

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5 changes: 5 additions & 0 deletions crates/hir-def/src/body/lower.rs
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Expand Up @@ -416,6 +416,11 @@ impl ExprCollector<'_> {
let expr = e.expr().map(|e| self.collect_expr(e));
self.alloc_expr(Expr::Return { expr }, syntax_ptr)
}
ast::Expr::BecomeExpr(e) => {
let expr =
e.expr().map(|e| self.collect_expr(e)).unwrap_or_else(|| self.missing_expr());
self.alloc_expr(Expr::Become { expr }, syntax_ptr)
}
ast::Expr::YieldExpr(e) => {
self.is_lowering_coroutine = true;
let expr = e.expr().map(|e| self.collect_expr(e));
Expand Down
5 changes: 5 additions & 0 deletions crates/hir-def/src/body/pretty.rs
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Expand Up @@ -261,6 +261,11 @@ impl Printer<'_> {
self.print_expr(*expr);
}
}
Expr::Become { expr } => {
w!(self, "become");
self.whitespace();
self.print_expr(*expr);
}
Expr::Yield { expr } => {
w!(self, "yield");
if let Some(expr) = expr {
Expand Down
4 changes: 4 additions & 0 deletions crates/hir-def/src/hir.rs
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Expand Up @@ -216,6 +216,9 @@ pub enum Expr {
Return {
expr: Option<ExprId>,
},
Become {
expr: ExprId,
},
Yield {
expr: Option<ExprId>,
},
Expand Down Expand Up @@ -410,6 +413,7 @@ impl Expr {
f(expr);
}
}
Expr::Become { expr } => f(*expr),
Expr::RecordLit { fields, spread, .. } => {
for field in fields.iter() {
f(field.expr);
Expand Down
3 changes: 3 additions & 0 deletions crates/hir-ty/src/infer/closure.rs
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Expand Up @@ -531,6 +531,9 @@ impl InferenceContext<'_> {
self.consume_expr(expr);
}
}
&Expr::Become { expr } => {
self.consume_expr(expr);
}
Expr::RecordLit { fields, spread, .. } => {
if let &Some(expr) = spread {
self.consume_expr(expr);
Expand Down
22 changes: 22 additions & 0 deletions crates/hir-ty/src/infer/expr.rs
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Expand Up @@ -502,6 +502,7 @@ impl InferenceContext<'_> {
self.result.standard_types.never.clone()
}
&Expr::Return { expr } => self.infer_expr_return(tgt_expr, expr),
&Expr::Become { expr } => self.infer_expr_become(expr),
Expr::Yield { expr } => {
if let Some((resume_ty, yield_ty)) = self.resume_yield_tys.clone() {
if let Some(expr) = expr {
Expand Down Expand Up @@ -1084,6 +1085,27 @@ impl InferenceContext<'_> {
self.result.standard_types.never.clone()
}

fn infer_expr_become(&mut self, expr: ExprId) -> Ty {
match &self.return_coercion {
Some(return_coercion) => {
let ret_ty = return_coercion.expected_ty();

let call_expr_ty =
self.infer_expr_inner(expr, &Expectation::HasType(ret_ty.clone()));

// NB: this should *not* coerce.
// tail calls don't support any coercions except lifetimes ones (like `&'static u8 -> &'a u8`).
self.unify(&call_expr_ty, &ret_ty);
}
None => {
// FIXME: diagnose `become` outside of functions
self.infer_expr_no_expect(expr);
}
}

self.result.standard_types.never.clone()
}

fn infer_expr_box(&mut self, inner_expr: ExprId, expected: &Expectation) -> Ty {
if let Some(box_id) = self.resolve_boxed_box() {
let table = &mut self.table;
Expand Down
3 changes: 3 additions & 0 deletions crates/hir-ty/src/infer/mutability.rs
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Expand Up @@ -93,6 +93,9 @@ impl InferenceContext<'_> {
self.infer_mut_expr(expr, Mutability::Not);
}
}
Expr::Become { expr } => {
self.infer_mut_expr(*expr, Mutability::Not);
}
Expr::RecordLit { path: _, fields, spread, ellipsis: _, is_assignee_expr: _ } => {
self.infer_mut_not_expr_iter(fields.iter().map(|it| it.expr).chain(*spread))
}
Expand Down
1 change: 1 addition & 0 deletions crates/hir-ty/src/mir/lower.rs
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Expand Up @@ -775,6 +775,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
self.set_terminator(current, TerminatorKind::Return, expr_id.into());
Ok(None)
}
Expr::Become { .. } => not_supported!("tail-calls"),
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MIR support is actually not hard (I already have a MIR impl in the compiler after all), but I'm not sure how to properly lower it from hir. become x is only valid if x is a call (f(x), y.m()) and MIR really would like to see this as simple as possible.

In the compiler I lower HIR->THIR as-is, then run a check on THIR that tail calls are well-formed and then do something akin to this:

let Expr::Call { ..... } = expr
    else { bug!("THIR checks should have noticed that tail call doesn't have a call") };

Not sure what is the best way to do this in r-a

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What is the problem of doing the same in r-a? Just instead of bug! use not_supported! or add a variant to MirLowerError.

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The problem is that THIR has much simpler representation of functions and I'm not sure how to correctly handle both function and method calls.

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Aha. How it will be a lowered into mir? It would be a new terminator, like BecomeCall?

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@WaffleLapkin WaffleLapkin Jun 8, 2023 •
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Yes, it will be a new TailCall terminator. There is an experimental branch, it looks like this:

    TailCall {
        /// The function that’s being called.
        func: Operand<'tcx>,
        /// Arguments the function is called with.
        /// These are owned by the callee, which is free to modify them.
        /// This allows the memory occupied by "by-value" arguments to be
        /// reused across function calls without duplicating the contents.
        args: Vec<Operand<'tcx>>,
        // FIXME(explicit_tail_calls): should we have the span for `become`? is this span accurate? do we need it?
        /// This `Span` is the span of the function, without the dot and receiver
        /// (e.g. `foo(a, b)` in `x.foo(a, b)`
        fn_span: Span,
    },

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So I see three ways to implement it:

  1. Handle all cases manually. Assuming that become doesn't support overloaded operators, it is just call and method call.
  2. Adding a field to InferenceResult for recording the simple form of function calls (or changing the current method_resolution field). This is similar to THIR in rustc.
  3. Adding a flag to MirLowerCtx, which if true it means the next Terminator::Call should be Terminator::TailCall.

If you want to go with 2, I would suggest doing it in a separate PR, to minimize git conflicts (Assuming this PR is going to be not merged in a long time)

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I think 3 is error prone with code like

become 1; // invalid
f(); // becomes tail call

2 I'm not exactly sure I understand.

Assuming that become doesn't support overloaded operators

Yes, this is true.

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I think 1 would be easiest to go with for now even if it's not the cleanest. 2 seems kind of invasive with the current structure I think

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This is also my understanding, yes. I'll try option 1.

Expr::Yield { .. } => not_supported!("yield"),
Expr::RecordLit { fields, path, spread, ellipsis: _, is_assignee_expr: _ } => {
let spread_place = match spread {
Expand Down
1 change: 1 addition & 0 deletions crates/ide-db/src/syntax_helpers/node_ext.rs
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Expand Up @@ -329,6 +329,7 @@ pub fn for_each_tail_expr(expr: &ast::Expr, cb: &mut dyn FnMut(&ast::Expr)) {
| ast::Expr::RecordExpr(_)
| ast::Expr::RefExpr(_)
| ast::Expr::ReturnExpr(_)
| ast::Expr::BecomeExpr(_)
| ast::Expr::TryExpr(_)
| ast::Expr::TupleExpr(_)
| ast::Expr::LetExpr(_)
Expand Down
14 changes: 14 additions & 0 deletions crates/parser/src/grammar/expressions/atom.rs
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Expand Up @@ -58,6 +58,7 @@ pub(super) const ATOM_EXPR_FIRST: TokenSet =
T![match],
T![move],
T![return],
T![become],
T![static],
T![try],
T![unsafe],
Expand Down Expand Up @@ -102,6 +103,7 @@ pub(super) fn atom_expr(
T![try] => try_block_expr(p, None),
T![match] => match_expr(p),
T![return] => return_expr(p),
T![become] => become_expr(p),
T![yield] => yield_expr(p),
T![do] if p.nth_at_contextual_kw(1, T![yeet]) => yeet_expr(p),
T![continue] => continue_expr(p),
Expand Down Expand Up @@ -621,6 +623,18 @@ fn return_expr(p: &mut Parser<'_>) -> CompletedMarker {
m.complete(p, RETURN_EXPR)
}

// test become_expr
// fn foo() {
// become foo();
// }
fn become_expr(p: &mut Parser<'_>) -> CompletedMarker {
assert!(p.at(T![become]));
let m = p.start();
p.bump(T![become]);
expr(p);
m.complete(p, BECOME_EXPR)
}

// test yield_expr
// fn foo() {
// yield;
Expand Down
6 changes: 5 additions & 1 deletion crates/parser/src/syntax_kind/generated.rs
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Expand Up @@ -90,6 +90,7 @@ pub enum SyntaxKind {
PUB_KW,
REF_KW,
RETURN_KW,
BECOME_KW,
SELF_KW,
SELF_TYPE_KW,
STATIC_KW,
Expand Down Expand Up @@ -195,6 +196,7 @@ pub enum SyntaxKind {
BLOCK_EXPR,
STMT_LIST,
RETURN_EXPR,
BECOME_EXPR,
YIELD_EXPR,
YEET_EXPR,
LET_EXPR,
Expand Down Expand Up @@ -307,6 +309,7 @@ impl SyntaxKind {
| PUB_KW
| REF_KW
| RETURN_KW
| BECOME_KW
| SELF_KW
| SELF_TYPE_KW
| STATIC_KW
Expand Down Expand Up @@ -425,6 +428,7 @@ impl SyntaxKind {
"pub" => PUB_KW,
"ref" => REF_KW,
"return" => RETURN_KW,
"become" => BECOME_KW,
"self" => SELF_KW,
"Self" => SELF_TYPE_KW,
"static" => STATIC_KW,
Expand Down Expand Up @@ -496,4 +500,4 @@ impl SyntaxKind {
}
}
#[macro_export]
macro_rules ! T { [;] => { $ crate :: SyntaxKind :: SEMICOLON } ; [,] => { $ crate :: SyntaxKind :: COMMA } ; ['('] => { $ crate :: SyntaxKind :: L_PAREN } ; [')'] => { $ crate :: SyntaxKind :: R_PAREN } ; ['{'] => { $ crate :: SyntaxKind :: L_CURLY } ; ['}'] => { $ crate :: SyntaxKind :: R_CURLY } ; ['['] => { $ crate :: SyntaxKind :: L_BRACK } ; [']'] => { $ crate :: SyntaxKind :: R_BRACK } ; [<] => { $ crate :: SyntaxKind :: L_ANGLE } ; [>] => { $ crate :: SyntaxKind :: R_ANGLE } ; [@] => { $ crate :: SyntaxKind :: AT } ; [#] => { $ crate :: SyntaxKind :: POUND } ; [~] => { $ crate :: SyntaxKind :: TILDE } ; [?] => { $ crate :: SyntaxKind :: QUESTION } ; [$] => { $ crate :: SyntaxKind :: DOLLAR } ; [&] => { $ crate :: SyntaxKind :: AMP } ; [|] => { $ crate :: SyntaxKind :: PIPE } ; [+] => { $ crate :: SyntaxKind :: PLUS } ; [*] => { $ crate :: SyntaxKind :: STAR } ; [/] => { $ crate :: SyntaxKind :: SLASH } ; [^] => { $ crate :: SyntaxKind :: CARET } ; [%] => { $ crate :: SyntaxKind :: PERCENT } ; [_] => { $ crate :: SyntaxKind :: UNDERSCORE } ; [.] => { $ crate :: SyntaxKind :: DOT } ; [..] => { $ crate :: SyntaxKind :: DOT2 } ; [...] => { $ crate :: SyntaxKind :: DOT3 } ; [..=] => { $ crate :: SyntaxKind :: DOT2EQ } ; [:] => { $ crate :: SyntaxKind :: COLON } ; [::] => { $ crate :: SyntaxKind :: COLON2 } ; [=] => { $ crate :: SyntaxKind :: EQ } ; [==] => { $ crate :: SyntaxKind :: EQ2 } ; [=>] => { $ crate :: SyntaxKind :: FAT_ARROW } ; [!] => { $ crate :: SyntaxKind :: BANG } ; [!=] => { $ crate :: SyntaxKind :: NEQ } ; [-] => { $ crate :: SyntaxKind :: MINUS } ; [->] => { $ crate :: SyntaxKind :: THIN_ARROW } ; [<=] => { $ crate :: SyntaxKind :: LTEQ } ; [>=] => { $ crate :: SyntaxKind :: GTEQ } ; [+=] => { $ crate :: SyntaxKind :: PLUSEQ } ; [-=] => { $ crate :: SyntaxKind :: MINUSEQ } ; [|=] => { $ crate :: SyntaxKind :: PIPEEQ } ; [&=] => { $ crate :: SyntaxKind :: AMPEQ } ; [^=] => { $ crate :: SyntaxKind :: CARETEQ } ; [/=] => { $ crate :: SyntaxKind :: SLASHEQ } ; [*=] => { $ crate :: SyntaxKind :: STAREQ } ; [%=] => { $ crate :: SyntaxKind :: PERCENTEQ } ; [&&] => { $ crate :: SyntaxKind :: AMP2 } ; [||] => { $ crate :: SyntaxKind :: PIPE2 } ; [<<] => { $ crate :: SyntaxKind :: SHL } ; [>>] => { $ crate :: SyntaxKind :: SHR } ; [<<=] => { $ crate :: SyntaxKind :: SHLEQ } ; [>>=] => { $ crate :: SyntaxKind :: SHREQ } ; [as] => { $ crate :: SyntaxKind :: AS_KW } ; [async] => { $ crate :: SyntaxKind :: ASYNC_KW } ; [await] => { $ crate :: SyntaxKind :: AWAIT_KW } ; [box] => { $ crate :: SyntaxKind :: BOX_KW } ; [break] => { $ crate :: SyntaxKind :: BREAK_KW } ; [const] => { $ crate :: SyntaxKind :: CONST_KW } ; [continue] => { $ crate :: SyntaxKind :: CONTINUE_KW } ; [crate] => { $ crate :: SyntaxKind :: CRATE_KW } ; [do] => { $ crate :: SyntaxKind :: DO_KW } ; [dyn] => { $ crate :: SyntaxKind :: DYN_KW } ; [else] => { $ crate :: SyntaxKind :: ELSE_KW } ; [enum] => { $ crate :: SyntaxKind :: ENUM_KW } ; [extern] => { $ crate :: SyntaxKind :: EXTERN_KW } ; [false] => { $ crate :: SyntaxKind :: FALSE_KW } ; [fn] => { $ crate :: SyntaxKind :: FN_KW } ; [for] => { $ crate :: SyntaxKind :: FOR_KW } ; [if] => { $ crate :: SyntaxKind :: IF_KW } ; [impl] => { $ crate :: SyntaxKind :: IMPL_KW } ; [in] => { $ crate :: SyntaxKind :: IN_KW } ; [let] => { $ crate :: SyntaxKind :: LET_KW } ; [loop] => { $ crate :: SyntaxKind :: LOOP_KW } ; [macro] => { $ crate :: SyntaxKind :: MACRO_KW } ; [match] => { $ crate :: SyntaxKind :: MATCH_KW } ; [mod] => { $ crate :: SyntaxKind :: MOD_KW } ; [move] => { $ crate :: SyntaxKind :: MOVE_KW } ; [mut] => { $ crate :: SyntaxKind :: MUT_KW } ; [pub] => { $ crate :: SyntaxKind :: PUB_KW } ; [ref] => { $ crate :: SyntaxKind :: REF_KW } ; [return] => { $ crate :: SyntaxKind :: RETURN_KW } ; [self] => { $ crate :: SyntaxKind :: SELF_KW } ; [Self] => { $ crate :: SyntaxKind :: SELF_TYPE_KW } ; [static] => { $ crate :: SyntaxKind :: STATIC_KW } ; [struct] => { $ crate :: SyntaxKind :: STRUCT_KW } ; [super] => { $ crate :: SyntaxKind :: SUPER_KW } ; [trait] => { $ crate :: SyntaxKind :: TRAIT_KW } ; [true] => { $ crate :: SyntaxKind :: TRUE_KW } ; [try] => { $ crate :: SyntaxKind :: TRY_KW } ; [type] => { $ crate :: SyntaxKind :: TYPE_KW } ; [unsafe] => { $ crate :: SyntaxKind :: UNSAFE_KW } ; [use] => { $ crate :: SyntaxKind :: USE_KW } ; [where] => { $ crate :: SyntaxKind :: WHERE_KW } ; [while] => { $ crate :: SyntaxKind :: WHILE_KW } ; [yield] => { $ crate :: SyntaxKind :: YIELD_KW } ; [auto] => { $ crate :: SyntaxKind :: AUTO_KW } ; [builtin] => { $ crate :: SyntaxKind :: BUILTIN_KW } ; [default] => { $ crate :: SyntaxKind :: DEFAULT_KW } ; [existential] => { $ crate :: SyntaxKind :: EXISTENTIAL_KW } ; [union] => { $ crate :: SyntaxKind :: UNION_KW } ; [raw] => { $ crate :: SyntaxKind :: RAW_KW } ; [macro_rules] => { $ crate :: SyntaxKind :: MACRO_RULES_KW } ; [yeet] => { $ crate :: SyntaxKind :: YEET_KW } ; [offset_of] => { $ crate :: SyntaxKind :: OFFSET_OF_KW } ; [asm] => { $ crate :: SyntaxKind :: ASM_KW } ; [format_args] => { $ crate :: SyntaxKind :: FORMAT_ARGS_KW } ; [lifetime_ident] => { $ crate :: SyntaxKind :: LIFETIME_IDENT } ; [ident] => { $ crate :: SyntaxKind :: IDENT } ; [shebang] => { $ crate :: SyntaxKind :: SHEBANG } ; }
macro_rules ! T { [;] => { $ crate :: SyntaxKind :: SEMICOLON } ; [,] => { $ crate :: SyntaxKind :: COMMA } ; ['('] => { $ crate :: SyntaxKind :: L_PAREN } ; [')'] => { $ crate :: SyntaxKind :: R_PAREN } ; ['{'] => { $ crate :: SyntaxKind :: L_CURLY } ; ['}'] => { $ crate :: SyntaxKind :: R_CURLY } ; ['['] => { $ crate :: SyntaxKind :: L_BRACK } ; [']'] => { $ crate :: SyntaxKind :: R_BRACK } ; [<] => { $ crate :: SyntaxKind :: L_ANGLE } ; [>] => { $ crate :: SyntaxKind :: R_ANGLE } ; [@] => { $ crate :: SyntaxKind :: AT } ; [#] => { $ crate :: SyntaxKind :: POUND } ; [~] => { $ crate :: SyntaxKind :: TILDE } ; [?] => { $ crate :: SyntaxKind :: QUESTION } ; [$] => { $ crate :: SyntaxKind :: DOLLAR } ; [&] => { $ crate :: SyntaxKind :: AMP } ; [|] => { $ crate :: SyntaxKind :: PIPE } ; [+] => { $ crate :: SyntaxKind :: PLUS } ; [*] => { $ crate :: SyntaxKind :: STAR } ; [/] => { $ crate :: SyntaxKind :: SLASH } ; [^] => { $ crate :: SyntaxKind :: CARET } ; [%] => { $ crate :: SyntaxKind :: PERCENT } ; [_] => { $ crate :: SyntaxKind :: UNDERSCORE } ; [.] => { $ crate :: SyntaxKind :: DOT } ; [..] => { $ crate :: SyntaxKind :: DOT2 } ; [...] => { $ crate :: SyntaxKind :: DOT3 } ; [..=] => { $ crate :: SyntaxKind :: DOT2EQ } ; [:] => { $ crate :: SyntaxKind :: COLON } ; [::] => { $ crate :: SyntaxKind :: COLON2 } ; [=] => { $ crate :: SyntaxKind :: EQ } ; [==] => { $ crate :: SyntaxKind :: EQ2 } ; [=>] => { $ crate :: SyntaxKind :: FAT_ARROW } ; [!] => { $ crate :: SyntaxKind :: BANG } ; [!=] => { $ crate :: SyntaxKind :: NEQ } ; [-] => { $ crate :: SyntaxKind :: MINUS } ; [->] => { $ crate :: SyntaxKind :: THIN_ARROW } ; [<=] => { $ crate :: SyntaxKind :: LTEQ } ; [>=] => { $ crate :: SyntaxKind :: GTEQ } ; [+=] => { $ crate :: SyntaxKind :: PLUSEQ } ; [-=] => { $ crate :: SyntaxKind :: MINUSEQ } ; [|=] => { $ crate :: SyntaxKind :: PIPEEQ } ; [&=] => { $ crate :: SyntaxKind :: AMPEQ } ; [^=] => { $ crate :: SyntaxKind :: CARETEQ } ; [/=] => { $ crate :: SyntaxKind :: SLASHEQ } ; [*=] => { $ crate :: SyntaxKind :: STAREQ } ; [%=] => { $ crate :: SyntaxKind :: PERCENTEQ } ; [&&] => { $ crate :: SyntaxKind :: AMP2 } ; [||] => { $ crate :: SyntaxKind :: PIPE2 } ; [<<] => { $ crate :: SyntaxKind :: SHL } ; [>>] => { $ crate :: SyntaxKind :: SHR } ; [<<=] => { $ crate :: SyntaxKind :: SHLEQ } ; [>>=] => { $ crate :: SyntaxKind :: SHREQ } ; [as] => { $ crate :: SyntaxKind :: AS_KW } ; [async] => { $ crate :: SyntaxKind :: ASYNC_KW } ; [await] => { $ crate :: SyntaxKind :: AWAIT_KW } ; [box] => { $ crate :: SyntaxKind :: BOX_KW } ; [break] => { $ crate :: SyntaxKind :: BREAK_KW } ; [const] => { $ crate :: SyntaxKind :: CONST_KW } ; [continue] => { $ crate :: SyntaxKind :: CONTINUE_KW } ; [crate] => { $ crate :: SyntaxKind :: CRATE_KW } ; [do] => { $ crate :: SyntaxKind :: DO_KW } ; [dyn] => { $ crate :: SyntaxKind :: DYN_KW } ; [else] => { $ crate :: SyntaxKind :: ELSE_KW } ; [enum] => { $ crate :: SyntaxKind :: ENUM_KW } ; [extern] => { $ crate :: SyntaxKind :: EXTERN_KW } ; [false] => { $ crate :: SyntaxKind :: FALSE_KW } ; [fn] => { $ crate :: SyntaxKind :: FN_KW } ; [for] => { $ crate :: SyntaxKind :: FOR_KW } ; [if] => { $ crate :: SyntaxKind :: IF_KW } ; [impl] => { $ crate :: SyntaxKind :: IMPL_KW } ; [in] => { $ crate :: SyntaxKind :: IN_KW } ; [let] => { $ crate :: SyntaxKind :: LET_KW } ; [loop] => { $ crate :: SyntaxKind :: LOOP_KW } ; [macro] => { $ crate :: SyntaxKind :: MACRO_KW } ; [match] => { $ crate :: SyntaxKind :: MATCH_KW } ; [mod] => { $ crate :: SyntaxKind :: MOD_KW } ; [move] => { $ crate :: SyntaxKind :: MOVE_KW } ; [mut] => { $ crate :: SyntaxKind :: MUT_KW } ; [pub] => { $ crate :: SyntaxKind :: PUB_KW } ; [ref] => { $ crate :: SyntaxKind :: REF_KW } ; [return] => { $ crate :: SyntaxKind :: RETURN_KW } ; [become] => { $ crate :: SyntaxKind :: BECOME_KW } ; [self] => { $ crate :: SyntaxKind :: SELF_KW } ; [Self] => { $ crate :: SyntaxKind :: SELF_TYPE_KW } ; [static] => { $ crate :: SyntaxKind :: STATIC_KW } ; [struct] => { $ crate :: SyntaxKind :: STRUCT_KW } ; [super] => { $ crate :: SyntaxKind :: SUPER_KW } ; [trait] => { $ crate :: SyntaxKind :: TRAIT_KW } ; [true] => { $ crate :: SyntaxKind :: TRUE_KW } ; [try] => { $ crate :: SyntaxKind :: TRY_KW } ; [type] => { $ crate :: SyntaxKind :: TYPE_KW } ; [unsafe] => { $ crate :: SyntaxKind :: UNSAFE_KW } ; [use] => { $ crate :: SyntaxKind :: USE_KW } ; [where] => { $ crate :: SyntaxKind :: WHERE_KW } ; [while] => { $ crate :: SyntaxKind :: WHILE_KW } ; [yield] => { $ crate :: SyntaxKind :: YIELD_KW } ; [auto] => { $ crate :: SyntaxKind :: AUTO_KW } ; [builtin] => { $ crate :: SyntaxKind :: BUILTIN_KW } ; [default] => { $ crate :: SyntaxKind :: DEFAULT_KW } ; [existential] => { $ crate :: SyntaxKind :: EXISTENTIAL_KW } ; [union] => { $ crate :: SyntaxKind :: UNION_KW } ; [raw] => { $ crate :: SyntaxKind :: RAW_KW } ; [macro_rules] => { $ crate :: SyntaxKind :: MACRO_RULES_KW } ; [yeet] => { $ crate :: SyntaxKind :: YEET_KW } ; [offset_of] => { $ crate :: SyntaxKind :: OFFSET_OF_KW } ; [asm] => { $ crate :: SyntaxKind :: ASM_KW } ; [format_args] => { $ crate :: SyntaxKind :: FORMAT_ARGS_KW } ; [lifetime_ident] => { $ crate :: SyntaxKind :: LIFETIME_IDENT } ; [ident] => { $ crate :: SyntaxKind :: IDENT } ; [shebang] => { $ crate :: SyntaxKind :: SHEBANG } ; }
31 changes: 31 additions & 0 deletions crates/parser/test_data/parser/inline/ok/0209_become_expr.rast
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@@ -0,0 +1,31 @@
SOURCE_FILE
FN
FN_KW "fn"
WHITESPACE " "
NAME
IDENT "foo"
PARAM_LIST
L_PAREN "("
R_PAREN ")"
WHITESPACE " "
BLOCK_EXPR
STMT_LIST
L_CURLY "{"
WHITESPACE "\n "
EXPR_STMT
BECOME_EXPR
BECOME_KW "become"
WHITESPACE " "
CALL_EXPR
PATH_EXPR
PATH
PATH_SEGMENT
NAME_REF
IDENT "foo"
ARG_LIST
L_PAREN "("
R_PAREN ")"
SEMICOLON ";"
WHITESPACE "\n"
R_CURLY "}"
WHITESPACE "\n"
3 changes: 3 additions & 0 deletions crates/parser/test_data/parser/inline/ok/0209_become_expr.rs
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Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
fn foo() {
become foo();
}
4 changes: 4 additions & 0 deletions crates/syntax/rust.ungram
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Expand Up @@ -367,6 +367,7 @@ Expr =
| RecordExpr
| RefExpr
| ReturnExpr
| BecomeExpr
| TryExpr
| TupleExpr
| WhileExpr
Expand Down Expand Up @@ -528,6 +529,9 @@ MatchGuard =
ReturnExpr =
Attr* 'return' Expr?

BecomeExpr =
Attr* 'become' Expr

YieldExpr =
Attr* 'yield' Expr?

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