diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs index 4b56cc5321b37..1b93017c5aa47 100644 --- a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs +++ b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs @@ -28,6 +28,11 @@ use crate::structured_errors::StructuredDiagnostic; use std::iter; use std::slice; +struct FnArgsAsTuple<'hir> { + first: &'hir hir::Expr<'hir>, + last: &'hir hir::Expr<'hir>, +} + impl<'a, 'tcx> FnCtxt<'a, 'tcx> { pub(in super::super) fn check_casts(&self) { let mut deferred_cast_checks = self.deferred_cast_checks.borrow_mut(); @@ -127,8 +132,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { let expected_arg_count = formal_input_tys.len(); - // expected_count, arg_count, error_code, sugg_unit - let mut error: Option<(usize, usize, &str, bool)> = None; + // expected_count, arg_count, error_code, sugg_unit, sugg_tuple_wrap_args + let mut error: Option<(usize, usize, &str, bool, Option>)> = None; // If the arguments should be wrapped in a tuple (ex: closures), unwrap them here let (formal_input_tys, expected_input_tys) = if tuple_arguments == TupleArguments { @@ -138,7 +143,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { ty::Tuple(arg_types) => { // Argument length differs if arg_types.len() != provided_args.len() { - error = Some((arg_types.len(), provided_args.len(), "E0057", false)); + error = Some((arg_types.len(), provided_args.len(), "E0057", false, None)); } let expected_input_tys = match expected_input_tys.get(0) { Some(&ty) => match ty.kind() { @@ -169,7 +174,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { if supplied_arg_count >= expected_arg_count { (formal_input_tys.to_vec(), expected_input_tys) } else { - error = Some((expected_arg_count, supplied_arg_count, "E0060", false)); + error = Some((expected_arg_count, supplied_arg_count, "E0060", false, None)); (self.err_args(supplied_arg_count), vec![]) } } else { @@ -181,7 +186,25 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } else { false }; - error = Some((expected_arg_count, supplied_arg_count, "E0061", sugg_unit)); + + // are we passing elements of a tuple without the tuple parentheses? + let expected_input_tys = if expected_input_tys.is_empty() { + // In most cases we can use expected_input_tys, but some callers won't have the type + // information, in which case we fall back to the types from the input expressions. + formal_input_tys + } else { + &*expected_input_tys + }; + + let sugg_tuple_wrap_args = self.suggested_tuple_wrap(expected_input_tys, provided_args); + + error = Some(( + expected_arg_count, + supplied_arg_count, + "E0061", + sugg_unit, + sugg_tuple_wrap_args, + )); (self.err_args(supplied_arg_count), vec![]) }; @@ -305,7 +328,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } // If there was an error in parameter count, emit that here - if let Some((expected_count, arg_count, err_code, sugg_unit)) = error { + if let Some((expected_count, arg_count, err_code, sugg_unit, sugg_tuple_wrap_args)) = error + { let (span, start_span, args, ctor_of) = match &call_expr.kind { hir::ExprKind::Call( hir::Expr { @@ -408,6 +432,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { String::from("()"), Applicability::MachineApplicable, ); + } else if let Some(FnArgsAsTuple { first, last }) = sugg_tuple_wrap_args { + err.multipart_suggestion( + "use parentheses to construct a tuple", + vec![ + (first.span.shrink_to_lo(), '('.to_string()), + (last.span.shrink_to_hi(), ')'.to_string()), + ], + Applicability::MachineApplicable, + ); } else { err.span_label( span, @@ -457,6 +490,35 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } } + fn suggested_tuple_wrap( + &self, + expected_input_tys: &[Ty<'tcx>], + provided_args: &'tcx [hir::Expr<'tcx>], + ) -> Option> { + let [expected_arg_type] = &expected_input_tys[..] else { return None }; + + let ty::Tuple(expected_elems) = self.resolve_vars_if_possible(*expected_arg_type).kind() + else { return None }; + + let expected_types: Vec<_> = expected_elems.iter().map(|k| k.expect_ty()).collect(); + let supplied_types: Vec<_> = provided_args.iter().map(|arg| self.check_expr(arg)).collect(); + + let all_match = iter::zip(expected_types, supplied_types) + .all(|(expected, supplied)| self.can_eq(self.param_env, expected, supplied).is_ok()); + + if all_match { + match provided_args { + [] => None, + [_] => unreachable!( + "shouldn't reach here - need count mismatch between 1-tuple and 1-argument" + ), + [first, .., last] => Some(FnArgsAsTuple { first, last }), + } + } else { + None + } + } + // AST fragment checking pub(in super::super) fn check_lit( &self, diff --git a/src/test/ui/suggestions/args-instead-of-tuple-errors.rs b/src/test/ui/suggestions/args-instead-of-tuple-errors.rs new file mode 100644 index 0000000000000..2c3ee5fcb8039 --- /dev/null +++ b/src/test/ui/suggestions/args-instead-of-tuple-errors.rs @@ -0,0 +1,16 @@ +// Ensure we don't suggest tuple-wrapping when we'd end up with a type error + +fn main() { + // we shouldn't suggest to fix these - `2` isn't a `bool` + + let _: Option<(i32, bool)> = Some(1, 2); + //~^ ERROR this enum variant takes 1 argument but 2 arguments were supplied + int_bool(1, 2); + //~^ ERROR this function takes 1 argument but 2 arguments were supplied + + let _: Option<(i8,)> = Some(); + //~^ ERROR this enum variant takes 1 argument but 0 arguments were supplied +} + +fn int_bool(_: (i32, bool)) { +} diff --git a/src/test/ui/suggestions/args-instead-of-tuple-errors.stderr b/src/test/ui/suggestions/args-instead-of-tuple-errors.stderr new file mode 100644 index 0000000000000..a2ad602dbd47a --- /dev/null +++ b/src/test/ui/suggestions/args-instead-of-tuple-errors.stderr @@ -0,0 +1,33 @@ +error[E0061]: this enum variant takes 1 argument but 2 arguments were supplied + --> $DIR/args-instead-of-tuple-errors.rs:6:34 + | +LL | let _: Option<(i32, bool)> = Some(1, 2); + | ^^^^ - - supplied 2 arguments + | | + | expected 1 argument + +error[E0061]: this function takes 1 argument but 2 arguments were supplied + --> $DIR/args-instead-of-tuple-errors.rs:8:5 + | +LL | int_bool(1, 2); + | ^^^^^^^^ - - supplied 2 arguments + | | + | expected 1 argument + | +note: function defined here + --> $DIR/args-instead-of-tuple-errors.rs:15:4 + | +LL | fn int_bool(_: (i32, bool)) { + | ^^^^^^^^ -------------- + +error[E0061]: this enum variant takes 1 argument but 0 arguments were supplied + --> $DIR/args-instead-of-tuple-errors.rs:11:28 + | +LL | let _: Option<(i8,)> = Some(); + | ^^^^-- supplied 0 arguments + | | + | expected 1 argument + +error: aborting due to 3 previous errors + +For more information about this error, try `rustc --explain E0061`. diff --git a/src/test/ui/suggestions/args-instead-of-tuple.fixed b/src/test/ui/suggestions/args-instead-of-tuple.fixed new file mode 100644 index 0000000000000..c9b8a41d469b9 --- /dev/null +++ b/src/test/ui/suggestions/args-instead-of-tuple.fixed @@ -0,0 +1,27 @@ +// Test suggesting tuples where bare arguments may have been passed +// See issue #86481 for details. + +// run-rustfix + +fn main() { + let _: Result<(i32, i8), ()> = Ok((1, 2)); + //~^ ERROR this enum variant takes 1 argument but 2 arguments were supplied + let _: Option<(i32, i8, &'static str)> = Some((1, 2, "hi")); + //~^ ERROR this enum variant takes 1 argument but 3 arguments were supplied + let _: Option<()> = Some(()); + //~^ ERROR this enum variant takes 1 argument but 0 arguments were supplied + + two_ints((1, 2)); //~ ERROR this function takes 1 argument + + with_generic((3, 4)); //~ ERROR this function takes 1 argument +} + +fn two_ints(_: (i32, i32)) { +} + +fn with_generic((a, b): (i32, T)) { + if false { + // test generics/bound handling + with_generic((a, b)); //~ ERROR this function takes 1 argument + } +} diff --git a/src/test/ui/suggestions/args-instead-of-tuple.rs b/src/test/ui/suggestions/args-instead-of-tuple.rs new file mode 100644 index 0000000000000..d4cc3024dd0d2 --- /dev/null +++ b/src/test/ui/suggestions/args-instead-of-tuple.rs @@ -0,0 +1,27 @@ +// Test suggesting tuples where bare arguments may have been passed +// See issue #86481 for details. + +// run-rustfix + +fn main() { + let _: Result<(i32, i8), ()> = Ok(1, 2); + //~^ ERROR this enum variant takes 1 argument but 2 arguments were supplied + let _: Option<(i32, i8, &'static str)> = Some(1, 2, "hi"); + //~^ ERROR this enum variant takes 1 argument but 3 arguments were supplied + let _: Option<()> = Some(); + //~^ ERROR this enum variant takes 1 argument but 0 arguments were supplied + + two_ints(1, 2); //~ ERROR this function takes 1 argument + + with_generic(3, 4); //~ ERROR this function takes 1 argument +} + +fn two_ints(_: (i32, i32)) { +} + +fn with_generic((a, b): (i32, T)) { + if false { + // test generics/bound handling + with_generic(a, b); //~ ERROR this function takes 1 argument + } +} diff --git a/src/test/ui/suggestions/args-instead-of-tuple.stderr b/src/test/ui/suggestions/args-instead-of-tuple.stderr new file mode 100644 index 0000000000000..172db7ee3df38 --- /dev/null +++ b/src/test/ui/suggestions/args-instead-of-tuple.stderr @@ -0,0 +1,84 @@ +error[E0061]: this enum variant takes 1 argument but 2 arguments were supplied + --> $DIR/args-instead-of-tuple.rs:7:36 + | +LL | let _: Result<(i32, i8), ()> = Ok(1, 2); + | ^^ - - supplied 2 arguments + | +help: use parentheses to construct a tuple + | +LL | let _: Result<(i32, i8), ()> = Ok((1, 2)); + | + + + +error[E0061]: this enum variant takes 1 argument but 3 arguments were supplied + --> $DIR/args-instead-of-tuple.rs:9:46 + | +LL | let _: Option<(i32, i8, &'static str)> = Some(1, 2, "hi"); + | ^^^^ - - ---- supplied 3 arguments + | +help: use parentheses to construct a tuple + | +LL | let _: Option<(i32, i8, &'static str)> = Some((1, 2, "hi")); + | + + + +error[E0061]: this enum variant takes 1 argument but 0 arguments were supplied + --> $DIR/args-instead-of-tuple.rs:11:25 + | +LL | let _: Option<()> = Some(); + | ^^^^-- supplied 0 arguments + | +help: expected the unit value `()`; create it with empty parentheses + | +LL | let _: Option<()> = Some(()); + | ++ + +error[E0061]: this function takes 1 argument but 2 arguments were supplied + --> $DIR/args-instead-of-tuple.rs:14:5 + | +LL | two_ints(1, 2); + | ^^^^^^^^ - - supplied 2 arguments + | +note: function defined here + --> $DIR/args-instead-of-tuple.rs:19:4 + | +LL | fn two_ints(_: (i32, i32)) { + | ^^^^^^^^ ------------- +help: use parentheses to construct a tuple + | +LL | two_ints((1, 2)); + | + + + +error[E0061]: this function takes 1 argument but 2 arguments were supplied + --> $DIR/args-instead-of-tuple.rs:16:5 + | +LL | with_generic(3, 4); + | ^^^^^^^^^^^^ - - supplied 2 arguments + | +note: function defined here + --> $DIR/args-instead-of-tuple.rs:22:4 + | +LL | fn with_generic((a, b): (i32, T)) { + | ^^^^^^^^^^^^ ---------------- +help: use parentheses to construct a tuple + | +LL | with_generic((3, 4)); + | + + + +error[E0061]: this function takes 1 argument but 2 arguments were supplied + --> $DIR/args-instead-of-tuple.rs:25:9 + | +LL | with_generic(a, b); + | ^^^^^^^^^^^^ - - supplied 2 arguments + | +note: function defined here + --> $DIR/args-instead-of-tuple.rs:22:4 + | +LL | fn with_generic((a, b): (i32, T)) { + | ^^^^^^^^^^^^ ---------------- +help: use parentheses to construct a tuple + | +LL | with_generic((a, b)); + | + + + +error: aborting due to 6 previous errors + +For more information about this error, try `rustc --explain E0061`.