From 5880ce396832fd94efb1fc90f2682f209712ba24 Mon Sep 17 00:00:00 2001 From: ben Date: Sun, 6 Oct 2019 19:56:05 +1300 Subject: [PATCH 1/2] Fix const arguments not displaying in types mismatch diagnostic. --- src/librustc/infer/error_reporting/mod.rs | 19 ++++++++++++++++++- .../slice-const-param-mismatch.stderr | 12 ++++++------ 2 files changed, 24 insertions(+), 7 deletions(-) diff --git a/src/librustc/infer/error_reporting/mod.rs b/src/librustc/infer/error_reporting/mod.rs index d31b527a55b69..f1192c7ce10a9 100644 --- a/src/librustc/infer/error_reporting/mod.rs +++ b/src/librustc/infer/error_reporting/mod.rs @@ -935,6 +935,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { .filter(|(a, b)| a == b) .count(); let len = sub1.len() - common_default_params; + let consts_offset = len - sub1.consts().count(); // Only draw `<...>` if there're lifetime/type arguments. if len > 0 { @@ -981,7 +982,8 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { // ^ elided type as this type argument was the same in both sides let type_arguments = sub1.types().zip(sub2.types()); let regions_len = sub1.regions().count(); - for (i, (ta1, ta2)) in type_arguments.take(len).enumerate() { + let num_display_types = consts_offset - regions_len; + for (i, (ta1, ta2)) in type_arguments.take(num_display_types).enumerate() { let i = i + regions_len; if ta1 == ta2 { values.0.push_normal("_"); @@ -994,6 +996,21 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { self.push_comma(&mut values.0, &mut values.1, len, i); } + // Do the same for const arguments, if they are equal, do not highlight and + // elide them from the output. + let const_arguments = sub1.consts().zip(sub2.consts()); + for (i, (ca1, ca2)) in const_arguments.enumerate() { + let i = i + consts_offset; + if ca1 == ca2 { + values.0.push_normal("_"); + values.1.push_normal("_"); + } else { + values.0.push_highlighted(ca1.to_string()); + values.1.push_highlighted(ca2.to_string()); + } + self.push_comma(&mut values.0, &mut values.1, len, i); + } + // Close the type argument bracket. // Only draw `<...>` if there're lifetime/type arguments. if len > 0 { diff --git a/src/test/ui/const-generics/slice-const-param-mismatch.stderr b/src/test/ui/const-generics/slice-const-param-mismatch.stderr index 72369ab24ebfc..380a70d664e05 100644 --- a/src/test/ui/const-generics/slice-const-param-mismatch.stderr +++ b/src/test/ui/const-generics/slice-const-param-mismatch.stderr @@ -12,8 +12,8 @@ error[E0308]: mismatched types LL | let _: ConstString<"Hello"> = ConstString::<"World">; | ^^^^^^^^^^^^^^^^^^^^^^ expected `"Hello"`, found `"World"` | - = note: expected type `ConstString<>` - found type `ConstString<>` + = note: expected type `ConstString<"Hello">` + found type `ConstString<"World">` error[E0308]: mismatched types --> $DIR/slice-const-param-mismatch.rs:11:33 @@ -21,8 +21,8 @@ error[E0308]: mismatched types LL | let _: ConstString<"ℇ㇈↦"> = ConstString::<"ℇ㇈↥">; | ^^^^^^^^^^^^^^^^^^^^^ expected `"ℇ㇈↦"`, found `"ℇ㇈↥"` | - = note: expected type `ConstString<>` - found type `ConstString<>` + = note: expected type `ConstString<"ℇ㇈↦">` + found type `ConstString<"ℇ㇈↥">` error[E0308]: mismatched types --> $DIR/slice-const-param-mismatch.rs:13:33 @@ -30,8 +30,8 @@ error[E0308]: mismatched types LL | let _: ConstBytes = ConstBytes::; | ^^^^^^^^^^^^^^^^^^^^ expected `b"AAA"`, found `b"BBB"` | - = note: expected type `ConstBytes<>` - found type `ConstBytes<>` + = note: expected type `ConstBytes` + found type `ConstBytes` error: aborting due to 3 previous errors From 74eac929c270e896752fb826a3fed34aa0ef5725 Mon Sep 17 00:00:00 2001 From: ben Date: Mon, 7 Oct 2019 20:39:08 +1300 Subject: [PATCH 2/2] Test diagnostic output of type mismatches for types that have const generics arguments. --- .../types-mismatch-const-args.rs | 19 ++++++++++++ .../types-mismatch-const-args.stderr | 29 +++++++++++++++++++ 2 files changed, 48 insertions(+) create mode 100644 src/test/ui/const-generics/types-mismatch-const-args.rs create mode 100644 src/test/ui/const-generics/types-mismatch-const-args.stderr diff --git a/src/test/ui/const-generics/types-mismatch-const-args.rs b/src/test/ui/const-generics/types-mismatch-const-args.rs new file mode 100644 index 0000000000000..b25b7331017e7 --- /dev/null +++ b/src/test/ui/const-generics/types-mismatch-const-args.rs @@ -0,0 +1,19 @@ +#![feature(const_generics)] +//~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash + +// tests the diagnostic output of type mismatches for types that have const generics arguments. + +use std::marker::PhantomData; + +struct A<'a, T, const X: u32, const Y: u32> { + data: PhantomData<&'a T> +} + +fn a<'a, 'b>() { + let _: A<'a, u32, {2u32}, {3u32}> = A::<'a, u32, {4u32}, {3u32}> { data: PhantomData }; + //~^ ERROR mismatched types + let _: A<'a, u16, {2u32}, {3u32}> = A::<'b, u32, {2u32}, {3u32}> { data: PhantomData }; + //~^ ERROR mismatched types +} + +pub fn main() {} diff --git a/src/test/ui/const-generics/types-mismatch-const-args.stderr b/src/test/ui/const-generics/types-mismatch-const-args.stderr new file mode 100644 index 0000000000000..805a3067d3b6b --- /dev/null +++ b/src/test/ui/const-generics/types-mismatch-const-args.stderr @@ -0,0 +1,29 @@ +warning: the feature `const_generics` is incomplete and may cause the compiler to crash + --> $DIR/types-mismatch-const-args.rs:1:12 + | +LL | #![feature(const_generics)] + | ^^^^^^^^^^^^^^ + | + = note: `#[warn(incomplete_features)]` on by default + +error[E0308]: mismatched types + --> $DIR/types-mismatch-const-args.rs:13:41 + | +LL | let _: A<'a, u32, {2u32}, {3u32}> = A::<'a, u32, {4u32}, {3u32}> { data: PhantomData }; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `2u32`, found `4u32` + | + = note: expected type `A<'_, _, 2u32, _>` + found type `A<'_, _, 4u32, _>` + +error[E0308]: mismatched types + --> $DIR/types-mismatch-const-args.rs:15:41 + | +LL | let _: A<'a, u16, {2u32}, {3u32}> = A::<'b, u32, {2u32}, {3u32}> { data: PhantomData }; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected u16, found u32 + | + = note: expected type `A<'a, u16, _, _>` + found type `A<'b, u32, _, _>` + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0308`.