From be1ed00712ce0b884e1fc9779f25b1758e994d0b Mon Sep 17 00:00:00 2001
From: kadmin <julianknodt@gmail.com>
Date: Sat, 13 Feb 2021 07:53:28 +0000
Subject: [PATCH 1/3] Add additional type info to mismatch err
---
compiler/rustc_typeck/src/astconv/generics.rs | 51 ++++++++++++++-----
src/test/ui/const-generics/diagnostics.rs | 13 +++++
src/test/ui/const-generics/diagnostics.stderr | 27 ++++++++++
.../ui/const-generics/invalid-enum.stderr | 20 --------
4 files changed, 79 insertions(+), 32 deletions(-)
create mode 100644 src/test/ui/const-generics/diagnostics.rs
create mode 100644 src/test/ui/const-generics/diagnostics.stderr
diff --git a/compiler/rustc_typeck/src/astconv/generics.rs b/compiler/rustc_typeck/src/astconv/generics.rs
index 67e37ca8d8e49..341f6fadba174 100644
--- a/compiler/rustc_typeck/src/astconv/generics.rs
+++ b/compiler/rustc_typeck/src/astconv/generics.rs
@@ -24,6 +24,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
tcx: TyCtxt<'_>,
arg: &GenericArg<'_>,
param: &GenericParamDef,
+ // DefId of the function
+ //body_def_id: DefId,
possible_ordering_error: bool,
help: Option<&str>,
) {
@@ -46,19 +48,44 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
// Specific suggestion set for diagnostics
match (arg, ¶m.kind) {
(
- GenericArg::Type(hir::Ty { kind: hir::TyKind::Path { .. }, .. }),
- GenericParamDefKind::Const { .. },
+ GenericArg::Type(hir::Ty {
+ kind: hir::TyKind::Path(rustc_hir::QPath::Resolved(_, path)),
+ ..
+ }),
+ GenericParamDefKind::Const,
) => {
- let suggestions = vec![
- (arg.span().shrink_to_lo(), String::from("{ ")),
- (arg.span().shrink_to_hi(), String::from(" }")),
- ];
- err.multipart_suggestion(
- "if this generic argument was intended as a const parameter, \
- try surrounding it with braces:",
- suggestions,
- Applicability::MaybeIncorrect,
- );
+ use rustc_hir::def::{DefKind, Res};
+ match path.res {
+ Res::Err => {}
+ Res::Def(DefKind::TyParam, src_def_id) => (|| {
+ let param_hir_id = match param.def_id.as_local() {
+ Some(x) => tcx.hir().local_def_id_to_hir_id(x),
+ None => return,
+ };
+ let param_name = tcx.hir().ty_param_name(param_hir_id);
+ let param_type = tcx.type_of(param.def_id);
+ if param_type.is_suggestable() {
+ err.span_suggestion(
+ tcx.def_span(src_def_id),
+ &format!("try changing to a const-generic parameter:"),
+ format!("const {}: {}", param_name, param_type),
+ Applicability::MaybeIncorrect,
+ );
+ }
+ })(),
+ _ => {
+ let suggestions = vec![
+ (arg.span().shrink_to_lo(), String::from("{ ")),
+ (arg.span().shrink_to_hi(), String::from(" }")),
+ ];
+ err.multipart_suggestion(
+ "if this generic argument was intended as a const parameter, \
+ try surrounding it with braces:",
+ suggestions,
+ Applicability::MaybeIncorrect,
+ );
+ }
+ }
}
(
GenericArg::Type(hir::Ty { kind: hir::TyKind::Array(_, len), .. }),
diff --git a/src/test/ui/const-generics/diagnostics.rs b/src/test/ui/const-generics/diagnostics.rs
new file mode 100644
index 0000000000000..c90e3d0e0eba9
--- /dev/null
+++ b/src/test/ui/const-generics/diagnostics.rs
@@ -0,0 +1,13 @@
+#![crate_type="lib"]
+#![feature(const_generics)]
+#![allow(incomplete_features)]
+
+struct A<const N: u8>;
+trait Foo {}
+impl Foo for A<N> {}
+//~^ ERROR type provided when a constant
+//~| ERROR cannot find type
+
+struct B<const N: u8>;
+impl<N> Foo for B<N> {}
+//~^ ERROR type provided when a constant
diff --git a/src/test/ui/const-generics/diagnostics.stderr b/src/test/ui/const-generics/diagnostics.stderr
new file mode 100644
index 0000000000000..a66858a310c85
--- /dev/null
+++ b/src/test/ui/const-generics/diagnostics.stderr
@@ -0,0 +1,27 @@
+error[E0412]: cannot find type `N` in this scope
+ --> $DIR/diagnostics.rs:7:16
+ |
+LL | struct A<const N: u8>;
+ | ---------------------- similarly named struct `A` defined here
+LL | trait Foo {}
+LL | impl Foo for A<N> {}
+ | ^ help: a struct with a similar name exists: `A`
+
+error[E0747]: type provided when a constant was expected
+ --> $DIR/diagnostics.rs:7:16
+ |
+LL | impl Foo for A<N> {}
+ | ^
+
+error[E0747]: type provided when a constant was expected
+ --> $DIR/diagnostics.rs:12:19
+ |
+LL | impl<N> Foo for B<N> {}
+ | - ^
+ | |
+ | help: try changing to a const-generic parameter:: `const N: u8`
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0412, E0747.
+For more information about an error, try `rustc --explain E0412`.
diff --git a/src/test/ui/const-generics/invalid-enum.stderr b/src/test/ui/const-generics/invalid-enum.stderr
index 7822fc072e35c..c062fc9ac88b3 100644
--- a/src/test/ui/const-generics/invalid-enum.stderr
+++ b/src/test/ui/const-generics/invalid-enum.stderr
@@ -30,44 +30,24 @@ error[E0747]: type provided when a constant was expected
|
LL | let _: Example<CompileFlag::A, _> = Example { x: 0 };
| ^^^^^^^^^^^^^^
- |
-help: if this generic argument was intended as a const parameter, try surrounding it with braces:
- |
-LL | let _: Example<{ CompileFlag::A }, _> = Example { x: 0 };
- | ^ ^
error[E0747]: type provided when a constant was expected
--> $DIR/invalid-enum.rs:33:18
|
LL | let _: Example<Example::ASSOC_FLAG, _> = Example { x: 0 };
| ^^^^^^^^^^^^^^^^^^^
- |
-help: if this generic argument was intended as a const parameter, try surrounding it with braces:
- |
-LL | let _: Example<{ Example::ASSOC_FLAG }, _> = Example { x: 0 };
- | ^ ^
error[E0747]: type provided when a constant was expected
--> $DIR/invalid-enum.rs:21:12
|
LL | test_1::<CompileFlag::A>();
| ^^^^^^^^^^^^^^
- |
-help: if this generic argument was intended as a const parameter, try surrounding it with braces:
- |
-LL | test_1::<{ CompileFlag::A }>();
- | ^ ^
error[E0747]: type provided when a constant was expected
--> $DIR/invalid-enum.rs:25:15
|
LL | test_2::<_, CompileFlag::A>(0);
| ^^^^^^^^^^^^^^
- |
-help: if this generic argument was intended as a const parameter, try surrounding it with braces:
- |
-LL | test_2::<_, { CompileFlag::A }>(0);
- | ^ ^
error: aborting due to 7 previous errors
From b97951b50f81862ccd997d48b20f50d05cd5157e Mon Sep 17 00:00:00 2001
From: kadmin <julianknodt@gmail.com>
Date: Sun, 14 Feb 2021 04:35:18 +0000
Subject: [PATCH 2/3] Update w/ comments
---
compiler/rustc_typeck/src/astconv/generics.rs | 60 ++++++++++---------
.../const-param-shadowing.stderr | 2 +-
src/test/ui/const-generics/diagnostics.rs | 11 +++-
src/test/ui/const-generics/diagnostics.stderr | 33 +++++++++-
src/test/ui/const-generics/invalid-enum.rs | 12 ++--
.../ui/const-generics/invalid-enum.stderr | 26 +++++++-
6 files changed, 101 insertions(+), 43 deletions(-)
diff --git a/compiler/rustc_typeck/src/astconv/generics.rs b/compiler/rustc_typeck/src/astconv/generics.rs
index 341f6fadba174..b421adbf9eab1 100644
--- a/compiler/rustc_typeck/src/astconv/generics.rs
+++ b/compiler/rustc_typeck/src/astconv/generics.rs
@@ -6,8 +6,9 @@ use crate::astconv::{
use crate::errors::AssocTypeBindingNotAllowed;
use crate::structured_errors::{StructuredDiagnostic, WrongNumberOfGenericArgs};
use rustc_ast::ast::ParamKindOrd;
-use rustc_errors::{struct_span_err, Applicability, ErrorReported};
+use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, ErrorReported};
use rustc_hir as hir;
+use rustc_hir::def::{DefKind, Res};
use rustc_hir::def_id::DefId;
use rustc_hir::GenericArg;
use rustc_middle::ty::{
@@ -24,8 +25,6 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
tcx: TyCtxt<'_>,
arg: &GenericArg<'_>,
param: &GenericParamDef,
- // DefId of the function
- //body_def_id: DefId,
possible_ordering_error: bool,
help: Option<&str>,
) {
@@ -45,6 +44,19 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
}
}
+ let add_braces_suggestion = |arg: &GenericArg<'_>, err: &mut DiagnosticBuilder<'_>| {
+ let suggestions = vec![
+ (arg.span().shrink_to_lo(), String::from("{ ")),
+ (arg.span().shrink_to_hi(), String::from(" }")),
+ ];
+ err.multipart_suggestion(
+ "if this generic argument was intended as a const parameter, \
+ surround it with braces",
+ suggestions,
+ Applicability::MaybeIncorrect,
+ );
+ };
+
// Specific suggestion set for diagnostics
match (arg, ¶m.kind) {
(
@@ -53,40 +65,34 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
..
}),
GenericParamDefKind::Const,
- ) => {
- use rustc_hir::def::{DefKind, Res};
- match path.res {
- Res::Err => {}
- Res::Def(DefKind::TyParam, src_def_id) => (|| {
- let param_hir_id = match param.def_id.as_local() {
- Some(x) => tcx.hir().local_def_id_to_hir_id(x),
- None => return,
- };
+ ) => match path.res {
+ Res::Err => {
+ add_braces_suggestion(arg, &mut err);
+ err.set_primary_message(
+ "unresolved item provided when a constant was expected",
+ );
+ }
+ Res::Def(DefKind::TyParam, src_def_id) => {
+ if let Some(param_local_id) = param.def_id.as_local() {
+ let param_hir_id = tcx.hir().local_def_id_to_hir_id(param_local_id);
let param_name = tcx.hir().ty_param_name(param_hir_id);
let param_type = tcx.type_of(param.def_id);
if param_type.is_suggestable() {
err.span_suggestion(
tcx.def_span(src_def_id),
- &format!("try changing to a const-generic parameter:"),
+ "consider changing this type paramater to a `const`-generic",
format!("const {}: {}", param_name, param_type),
Applicability::MaybeIncorrect,
);
- }
- })(),
- _ => {
- let suggestions = vec![
- (arg.span().shrink_to_lo(), String::from("{ ")),
- (arg.span().shrink_to_hi(), String::from(" }")),
- ];
- err.multipart_suggestion(
- "if this generic argument was intended as a const parameter, \
- try surrounding it with braces:",
- suggestions,
- Applicability::MaybeIncorrect,
- );
+ };
}
}
- }
+ _ => add_braces_suggestion(arg, &mut err),
+ },
+ (
+ GenericArg::Type(hir::Ty { kind: hir::TyKind::Path(_), .. }),
+ GenericParamDefKind::Const,
+ ) => add_braces_suggestion(arg, &mut err),
(
GenericArg::Type(hir::Ty { kind: hir::TyKind::Array(_, len), .. }),
GenericParamDefKind::Const { .. },
diff --git a/src/test/ui/const-generics/const-param-shadowing.stderr b/src/test/ui/const-generics/const-param-shadowing.stderr
index 7447ca3ff3631..17ccd2f3527b0 100644
--- a/src/test/ui/const-generics/const-param-shadowing.stderr
+++ b/src/test/ui/const-generics/const-param-shadowing.stderr
@@ -4,7 +4,7 @@ error[E0747]: type provided when a constant was expected
LL | fn test<const N: usize>() -> Foo<N> {
| ^
|
-help: if this generic argument was intended as a const parameter, try surrounding it with braces:
+help: if this generic argument was intended as a const parameter, surround it with braces
|
LL | fn test<const N: usize>() -> Foo<{ N }> {
| ^ ^
diff --git a/src/test/ui/const-generics/diagnostics.rs b/src/test/ui/const-generics/diagnostics.rs
index c90e3d0e0eba9..1581af5ab2751 100644
--- a/src/test/ui/const-generics/diagnostics.rs
+++ b/src/test/ui/const-generics/diagnostics.rs
@@ -1,13 +1,18 @@
#![crate_type="lib"]
-#![feature(const_generics)]
+#![feature(min_const_generics)]
#![allow(incomplete_features)]
struct A<const N: u8>;
trait Foo {}
impl Foo for A<N> {}
-//~^ ERROR type provided when a constant
-//~| ERROR cannot find type
+//~^ ERROR cannot find type
+//~| unresolved item provided when a constant
struct B<const N: u8>;
impl<N> Foo for B<N> {}
//~^ ERROR type provided when a constant
+
+struct C<const C: u8, const N: u8>;
+impl<const N: u8> Foo for C<N, T> {}
+//~^ ERROR cannot find type
+//~| unresolved item provided when a constant
diff --git a/src/test/ui/const-generics/diagnostics.stderr b/src/test/ui/const-generics/diagnostics.stderr
index a66858a310c85..33f5337eb8072 100644
--- a/src/test/ui/const-generics/diagnostics.stderr
+++ b/src/test/ui/const-generics/diagnostics.stderr
@@ -7,11 +7,25 @@ LL | trait Foo {}
LL | impl Foo for A<N> {}
| ^ help: a struct with a similar name exists: `A`
-error[E0747]: type provided when a constant was expected
+error[E0412]: cannot find type `T` in this scope
+ --> $DIR/diagnostics.rs:16:32
+ |
+LL | struct A<const N: u8>;
+ | ---------------------- similarly named struct `A` defined here
+...
+LL | impl<const N: u8> Foo for C<N, T> {}
+ | ^ help: a struct with a similar name exists: `A`
+
+error[E0747]: unresolved item provided when a constant was expected
--> $DIR/diagnostics.rs:7:16
|
LL | impl Foo for A<N> {}
| ^
+ |
+help: if this generic argument was intended as a const parameter, surround it with braces
+ |
+LL | impl Foo for A<{ N }> {}
+ | ^ ^
error[E0747]: type provided when a constant was expected
--> $DIR/diagnostics.rs:12:19
@@ -19,9 +33,22 @@ error[E0747]: type provided when a constant was expected
LL | impl<N> Foo for B<N> {}
| - ^
| |
- | help: try changing to a const-generic parameter:: `const N: u8`
+ | help: consider changing this type paramater to a `const`-generic: `const N: u8`
+
+error[E0747]: unresolved item provided when a constant was expected
+ --> $DIR/diagnostics.rs:16:32
+ |
+LL | impl<const N: u8> Foo for C<N, T> {}
+ | ^
+ |
+ = note: type arguments must be provided before constant arguments
+ = help: reorder the arguments: consts: `<C, N>`
+help: if this generic argument was intended as a const parameter, surround it with braces
+ |
+LL | impl<const N: u8> Foo for C<N, { T }> {}
+ | ^ ^
-error: aborting due to 3 previous errors
+error: aborting due to 5 previous errors
Some errors have detailed explanations: E0412, E0747.
For more information about an error, try `rustc --explain E0412`.
diff --git a/src/test/ui/const-generics/invalid-enum.rs b/src/test/ui/const-generics/invalid-enum.rs
index 4ca10ed8b71a2..32939dcd2861b 100644
--- a/src/test/ui/const-generics/invalid-enum.rs
+++ b/src/test/ui/const-generics/invalid-enum.rs
@@ -3,14 +3,14 @@
#[derive(PartialEq, Eq)]
enum CompileFlag {
- A,
- B,
+ A,
+ B,
}
pub fn test_1<const CF: CompileFlag>() {}
pub fn test_2<T, const CF: CompileFlag>(x: T) {}
pub struct Example<const CF: CompileFlag, T=u32>{
- x: T,
+ x: T,
}
impl<const CF: CompileFlag, T> Example<CF, T> {
@@ -20,15 +20,15 @@ impl<const CF: CompileFlag, T> Example<CF, T> {
pub fn main() {
test_1::<CompileFlag::A>();
//~^ ERROR: expected type, found variant
- //~| ERROR: type provided when a constant was expected
+ //~| ERROR: unresolved item provided when a constant was expected
test_2::<_, CompileFlag::A>(0);
//~^ ERROR: expected type, found variant
- //~| ERROR: type provided when a constant was expected
+ //~| ERROR: unresolved item provided when a constant was expected
let _: Example<CompileFlag::A, _> = Example { x: 0 };
//~^ ERROR: expected type, found variant
- //~| ERROR: type provided when a constant was expected
+ //~| ERROR: unresolved item provided when a constant was expected
let _: Example<Example::ASSOC_FLAG, _> = Example { x: 0 };
//~^ ERROR: type provided when a constant was expected
diff --git a/src/test/ui/const-generics/invalid-enum.stderr b/src/test/ui/const-generics/invalid-enum.stderr
index c062fc9ac88b3..cfbc61f02543b 100644
--- a/src/test/ui/const-generics/invalid-enum.stderr
+++ b/src/test/ui/const-generics/invalid-enum.stderr
@@ -25,29 +25,49 @@ LL | let _: Example<CompileFlag::A, _> = Example { x: 0 };
| not a type
| help: try using the variant's enum: `CompileFlag`
-error[E0747]: type provided when a constant was expected
+error[E0747]: unresolved item provided when a constant was expected
--> $DIR/invalid-enum.rs:29:18
|
LL | let _: Example<CompileFlag::A, _> = Example { x: 0 };
| ^^^^^^^^^^^^^^
+ |
+help: if this generic argument was intended as a const parameter, surround it with braces
+ |
+LL | let _: Example<{ CompileFlag::A }, _> = Example { x: 0 };
+ | ^ ^
error[E0747]: type provided when a constant was expected
--> $DIR/invalid-enum.rs:33:18
|
LL | let _: Example<Example::ASSOC_FLAG, _> = Example { x: 0 };
| ^^^^^^^^^^^^^^^^^^^
+ |
+help: if this generic argument was intended as a const parameter, surround it with braces
+ |
+LL | let _: Example<{ Example::ASSOC_FLAG }, _> = Example { x: 0 };
+ | ^ ^
-error[E0747]: type provided when a constant was expected
+error[E0747]: unresolved item provided when a constant was expected
--> $DIR/invalid-enum.rs:21:12
|
LL | test_1::<CompileFlag::A>();
| ^^^^^^^^^^^^^^
+ |
+help: if this generic argument was intended as a const parameter, surround it with braces
+ |
+LL | test_1::<{ CompileFlag::A }>();
+ | ^ ^
-error[E0747]: type provided when a constant was expected
+error[E0747]: unresolved item provided when a constant was expected
--> $DIR/invalid-enum.rs:25:15
|
LL | test_2::<_, CompileFlag::A>(0);
| ^^^^^^^^^^^^^^
+ |
+help: if this generic argument was intended as a const parameter, surround it with braces
+ |
+LL | test_2::<_, { CompileFlag::A }>(0);
+ | ^ ^
error: aborting due to 7 previous errors
From f52029553fa97153eb7f3fc724523cc1a61dfaba Mon Sep 17 00:00:00 2001
From: kadmin <julianknodt@gmail.com>
Date: Tue, 16 Feb 2021 19:03:22 +0000
Subject: [PATCH 3/3] Remove ordering hint
---
compiler/rustc_typeck/src/astconv/generics.rs | 4 +++-
src/test/ui/const-generics/diagnostics.stderr | 2 --
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/compiler/rustc_typeck/src/astconv/generics.rs b/compiler/rustc_typeck/src/astconv/generics.rs
index b421adbf9eab1..0ea0ccaceabd4 100644
--- a/compiler/rustc_typeck/src/astconv/generics.rs
+++ b/compiler/rustc_typeck/src/astconv/generics.rs
@@ -70,7 +70,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
add_braces_suggestion(arg, &mut err);
err.set_primary_message(
"unresolved item provided when a constant was expected",
- );
+ )
+ .emit();
+ return;
}
Res::Def(DefKind::TyParam, src_def_id) => {
if let Some(param_local_id) = param.def_id.as_local() {
diff --git a/src/test/ui/const-generics/diagnostics.stderr b/src/test/ui/const-generics/diagnostics.stderr
index 33f5337eb8072..7d038ff955d6c 100644
--- a/src/test/ui/const-generics/diagnostics.stderr
+++ b/src/test/ui/const-generics/diagnostics.stderr
@@ -41,8 +41,6 @@ error[E0747]: unresolved item provided when a constant was expected
LL | impl<const N: u8> Foo for C<N, T> {}
| ^
|
- = note: type arguments must be provided before constant arguments
- = help: reorder the arguments: consts: `<C, N>`
help: if this generic argument was intended as a const parameter, surround it with braces
|
LL | impl<const N: u8> Foo for C<N, { T }> {}