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Improve checking for attribute
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@Amanieu
Amanieu committed Feb 25, 2021
1 parent 22184a0 commit 00afbe7
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Showing 3 changed files with 85 additions and 63 deletions.
103 changes: 56 additions & 47 deletions compiler/rustc_passes/src/check_attr.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -760,7 +760,7 @@ impl CheckAttrVisitor<'tcx> {
target: Target,
item: Option<ItemLike<'_>>,
) -> bool {
let is_function = matches!(target, Target::Fn | Target::Method(..) | Target::ForeignFn);
let is_function = matches!(target, Target::Fn | Target::Method(..));
if !is_function {
self.tcx
.sess
Expand All @@ -776,55 +776,64 @@ impl CheckAttrVisitor<'tcx> {
Some(it) => it,
};

let (decl, generics) = match item {
Some(ItemLike::Item(Item {
kind: ItemKind::Fn(FnSig { decl, .. }, generics, _),
..
})) => (decl, generics),
_ => bug!("should be a function item"),
};

for param in generics.params {
match param.kind {
hir::GenericParamKind::Const { .. } => {}
_ => {
self.tcx
.sess
.struct_span_err(
attr.span,
"#[rustc_legacy_const_generics] functions must \
only have const generics",
)
.span_label(param.span, "non-const generic parameter")
.emit();
return false;
}
}
}

if list.len() != generics.params.len() {
self.tcx
.sess
.struct_span_err(
attr.span,
"#[rustc_legacy_const_generics] must have one index for each generic parameter",
)
.span_label(generics.span, "generic parameters")
.emit();
return false;
}

let arg_count = decl.inputs.len() as u128 + generics.params.len() as u128;
let mut invalid_args = vec![];
for meta in list {
if let Some(LitKind::Int(val, _)) = meta.literal().map(|lit| &lit.kind) {
if let Some(ItemLike::Item(Item {
kind: ItemKind::Fn(FnSig { decl, .. }, generics, _),
..
}))
| Some(ItemLike::ForeignItem(ForeignItem {
kind: ForeignItemKind::Fn(decl, _, generics),
..
})) = item
{
let arg_count = decl.inputs.len() as u128 + generics.params.len() as u128;
for param in generics.params {
match param.kind {
hir::GenericParamKind::Const { .. } => {}
_ => {
self.tcx
.sess
.struct_span_err(
meta.span(),
"#[rustc_legacy_const_generics] functions must \
only have const generics",
)
.span_label(param.span, "non-const generic parameter")
.emit();
break;
}
}
}
if *val >= arg_count {
let span = meta.span();
self.tcx
.sess
.struct_span_err(span, "index exceeds number of arguments")
.span_label(
span,
format!(
"there {} only {} argument{}",
if arg_count != 1 { "are" } else { "is" },
arg_count,
pluralize!(arg_count)
),
)
.emit();
return false;
}
} else {
bug!("should be a function item");
if *val >= arg_count {
let span = meta.span();
self.tcx
.sess
.struct_span_err(span, "index exceeds number of arguments")
.span_label(
span,
format!(
"there {} only {} argument{}",
if arg_count != 1 { "are" } else { "is" },
arg_count,
pluralize!(arg_count)
),
)
.emit();
return false;
}
} else {
invalid_args.push(meta.span());
Expand Down
14 changes: 7 additions & 7 deletions src/test/ui/invalid/invalid-rustc_legacy_const_generics-arguments.rs
View file
Original file line number Diff line number Diff line change
@@ -1,29 +1,29 @@
#![feature(rustc_attrs)]

#[rustc_legacy_const_generics(0)] //~ ERROR index exceeds number of arguments
#[rustc_legacy_const_generics(0)] //~ ERROR #[rustc_legacy_const_generics] must have one index for
fn foo1() {}

#[rustc_legacy_const_generics(1)] //~ ERROR index exceeds number of arguments
fn foo2(_: u8) {}
fn foo2<const X: usize>() {}

#[rustc_legacy_const_generics(2)] //~ ERROR index exceeds number of arguments
fn foo3<const X: usize>(_: u8) {}

#[rustc_legacy_const_generics(a)] //~ ERROR arguments should be non-negative integers
fn foo4() {}
fn foo4<const X: usize>() {}

#[rustc_legacy_const_generics(1, a, 2, b)] //~ ERROR arguments should be non-negative integers
fn foo5(_: u8, _: u8, _: u8) {}
fn foo5<const X: usize, const Y: usize, const Z: usize, const W: usize>() {}

#[rustc_legacy_const_generics(0)] //~ ERROR attribute should be applied to a function
struct S;

#[rustc_legacy_const_generics(0usize)] //~ ERROR suffixed literals are not allowed in attributes
fn foo6(_: u8) {}
fn foo6<const X: usize>() {}

extern {
#[rustc_legacy_const_generics(1)] //~ ERROR index exceeds number of arguments
fn foo7(_: u8);
#[rustc_legacy_const_generics(1)] //~ ERROR attribute should be applied to a function
fn foo7<const X: usize>(); //~ ERROR foreign items may not have const parameters
}

#[rustc_legacy_const_generics(0)] //~ ERROR #[rustc_legacy_const_generics] functions must only have
Expand Down
31 changes: 22 additions & 9 deletions src/test/ui/invalid/invalid-rustc_legacy_const_generics-arguments.stderr
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,11 +18,13 @@ error: malformed `rustc_legacy_const_generics` attribute input
LL | #[rustc_legacy_const_generics = 1]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[rustc_legacy_const_generics(N)]`

error: index exceeds number of arguments
--> $DIR/invalid-rustc_legacy_const_generics-arguments.rs:3:31
error: #[rustc_legacy_const_generics] must have one index for each generic parameter
--> $DIR/invalid-rustc_legacy_const_generics-arguments.rs:3:1
|
LL | #[rustc_legacy_const_generics(0)]
| ^ there are only 0 arguments
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | fn foo1() {}
| - generic parameters

error: index exceeds number of arguments
--> $DIR/invalid-rustc_legacy_const_generics-arguments.rs:6:31
Expand Down Expand Up @@ -57,18 +59,29 @@ LL | struct S;
| --------- not a function

error: #[rustc_legacy_const_generics] functions must only have const generics
--> $DIR/invalid-rustc_legacy_const_generics-arguments.rs:29:31
--> $DIR/invalid-rustc_legacy_const_generics-arguments.rs:29:1
|
LL | #[rustc_legacy_const_generics(0)]
| ^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | fn foo8<X>() {}
| - non-const generic parameter

error: index exceeds number of arguments
--> $DIR/invalid-rustc_legacy_const_generics-arguments.rs:25:35
error: attribute should be applied to a function
--> $DIR/invalid-rustc_legacy_const_generics-arguments.rs:25:5
|
LL | #[rustc_legacy_const_generics(1)]
| ^ there is only 1 argument
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | fn foo7<const X: usize>();
| -------------------------- not a function

error[E0044]: foreign items may not have const parameters
--> $DIR/invalid-rustc_legacy_const_generics-arguments.rs:26:5
|
LL | fn foo7<const X: usize>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ can't have const parameters
|
= help: replace the const parameters with concrete consts

error: aborting due to 11 previous errors
error: aborting due to 12 previous errors

For more information about this error, try `rustc --explain E0044`.

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