nordic-dev.net/rust
nordic-dev.net/rust
2
0
Fork 0
mirror of https://github.com/rust-lang/rust.git synced 2024-11-22 14:55:26 +00:00
Code Issues Packages Projects Releases Wiki Activity

Improve an error involving attribute values.

Browse Source 
Attribute values must be literals. The error you get when that doesn't
hold is pretty bad, e.g.:
```
unexpected expression: 1 + 1
```
You also get the same error if the attribute value is a literal, but an
invalid literal, e.g.:
```
unexpected expression: "foo"suffix
```

This commit does two things.
- Changes the error message to "attribute value must be a literal",
  which gives a better idea of what the problem is and how to fix it. It
  also no longer prints the invalid expression, because the carets below
  highlight it anyway.
- Separates the "not a literal" case from the "invalid literal" case.
  Which means invalid literals now get the specific error at the literal
  level, rather than at the attribute level.
This commit is contained in:
Nicholas Nethercote 2023-12-12 09:55:50 +11:00
parent 57010939ed
commit 226edf64fa
17 changed files with 87 additions and 62 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
compiler/rustc_parse/src/validate_attr.rs
View File

@ -6,9 +6,9 @@ use rustc_ast::token::Delimiter;
use rustc_ast::tokenstream::DelimSpan;
use rustc_ast::MetaItemKind;
use rustc_ast::{self as ast, AttrArgs, AttrArgsEq, Attribute, DelimArgs, MetaItem};
use rustc_ast_pretty::pprust;
use rustc_errors::{Applicability, FatalError, PResult};
use rustc_feature::{AttributeTemplate, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP};
use rustc_session::errors::report_lit_error;
use rustc_session::lint::builtin::ILL_FORMED_ATTRIBUTE_INPUT;
use rustc_session::parse::ParseSess;
use rustc_span::{sym, Span, Symbol};
@ -51,28 +51,44 @@ pub fn parse_meta<'a>(sess: &'a ParseSess, attr: &Attribute) -> PResult<'a, Meta
MetaItemKind::List(nmis)
}
AttrArgs::Eq(_, AttrArgsEq::Ast(expr)) => {
if let ast::ExprKind::Lit(token_lit) = expr.kind
&& let Ok(lit) = ast::MetaItemLit::from_token_lit(token_lit, expr.span)
{
if token_lit.suffix.is_some() {
let mut err = sess.span_diagnostic.struct_span_err(
expr.span,
"suffixed literals are not allowed in attributes",
);
err.help(
"instead of using a suffixed literal (`1u8`, `1.0f32`, etc.), \
use an unsuffixed version (`1`, `1.0`, etc.)",
);
return Err(err);
} else {
MetaItemKind::NameValue(lit)
}
if let ast::ExprKind::Lit(token_lit) = expr.kind {
let res = ast::MetaItemLit::from_token_lit(token_lit, expr.span);
let res = match res {
Ok(lit) => {
if token_lit.suffix.is_some() {
let mut err = sess.span_diagnostic.struct_span_err(
expr.span,
"suffixed literals are not allowed in attributes",
);
err.help(
"instead of using a suffixed literal (`1u8`, `1.0f32`, etc.), \
use an unsuffixed version (`1`, `1.0`, etc.)",
);
return Err(err);
} else {
MetaItemKind::NameValue(lit)
}
}
Err(err) => {
report_lit_error(sess, err, token_lit, expr.span);
let lit = ast::MetaItemLit {
symbol: token_lit.symbol,
suffix: token_lit.suffix,
kind: ast::LitKind::Err,
span: expr.span,
};
MetaItemKind::NameValue(lit)
}
};
res
} else {
// The non-error case can happen with e.g. `#[foo = 1+1]`. The error case can
// happen with e.g. `#[foo = include_str!("nonexistent-file.rs")]`; in that
// case we delay the error because an earlier error will have already been
// reported.
let msg = format!("unexpected expression: `{}`", pprust::expr_to_string(expr));
// Example cases:
// - `#[foo = 1+1]`: results in `ast::ExprKind::BinOp`.
// - `#[foo = include_str!("nonexistent-file.rs")]`:
// results in `ast::ExprKind::Err`. In that case we delay
// the error because an earlier error will have already
// been reported.
let msg = format!("attribute value must be a literal");
let mut err = sess.span_diagnostic.struct_span_err(expr.span, msg);
if let ast::ExprKind::Err = expr.kind {
err.downgrade_to_delayed_bug();

4
tests/ui/attributes/issue-90873.rs
View File

@ -1,9 +1,9 @@
#![u=||{static d=||1;}]
//~^ unexpected expression
//~^ attribute value must be a literal
//~| cannot find attribute `u` in this scope
//~| missing type for `static` item
#![a={impl std::ops::Neg for i8 {}}]
//~^ ERROR unexpected expression
//~^ ERROR attribute value must be a literal
//~| ERROR cannot find attribute `a` in this scope
//~| ERROR `main` function not found in crate `issue_90873`

9
tests/ui/attributes/issue-90873.stderr
View File

@ -1,15 +1,10 @@
error: unexpected expression: `||
{
static d: _ = || 1;
}`
error: attribute value must be a literal
--> $DIR/issue-90873.rs:1:6
|
LL | #![u=||{static d=||1;}]
| ^^^^^^^^^^^^^^^^^
error: unexpected expression: `{
impl std::ops::Neg for i8 {}
}`
error: attribute value must be a literal
--> $DIR/issue-90873.rs:6:6
|
LL | #![a={impl std::ops::Neg for i8 {}}]

4
tests/ui/attributes/key-value-expansion-on-mac.rs
View File

@ -7,8 +7,8 @@ macro_rules! bar {
// FIXME?: `bar` here expands before `stringify` has a chance to expand.
// `#[rustc_dummy = ...]` is validated and dropped during expansion of `bar`,
// the "unexpected expression" errors comes from the validation.
#[rustc_dummy = stringify!(b)] //~ ERROR unexpected expression: `stringify!(b)`
// the "attribute value must be a literal" error comes from the validation.
#[rustc_dummy = stringify!(b)] //~ ERROR attribute value must be a literal
bar!();
fn main() {}

2
tests/ui/attributes/key-value-expansion-on-mac.stderr
View File

@ -1,4 +1,4 @@
error: unexpected expression: `stringify!(b)`
error: attribute value must be a literal
--> $DIR/key-value-expansion-on-mac.rs:11:17
|
LL | #[rustc_dummy = stringify!(b)]

6
tests/ui/attributes/key-value-expansion.rs
View File

@ -18,13 +18,13 @@ macro_rules! bug {
// Any expressions containing macro call `X` that's more complex than `X` itself.
// Parentheses will work.
bug!((column!())); //~ ERROR unexpected expression: `(7u32)`
bug!((column!())); //~ ERROR attribute value must be a literal
// Original test case.
macro_rules! bug {
() => {
bug!("bug" + stringify!(found)); //~ ERROR unexpected expression: `"bug" + "found"`
bug!("bug" + stringify!(found)); //~ ERROR attribute value must be a literal
};
($test:expr) => {
#[doc = $test]
@ -46,7 +46,7 @@ macro_rules! doc_comment {
macro_rules! some_macro {
($t1: ty) => {
doc_comment! {format!("{coor}", coor = stringify!($t1)).as_str()}
//~^ ERROR unexpected expression: `{
//~^ ERROR attribute value must be a literal
};
}

6
tests/ui/attributes/key-value-expansion.stderr
View File

@ -1,10 +1,10 @@
error: unexpected expression: `(7u32)`
error: attribute value must be a literal
--> $DIR/key-value-expansion.rs:21:6
|
LL | bug!((column!()));
| ^^^^^^^^^^^
error: unexpected expression: `"bug" + "found"`
error: attribute value must be a literal
--> $DIR/key-value-expansion.rs:27:14
|
LL | bug!("bug" + stringify!(found));
@ -15,7 +15,7 @@ LL | bug!();
|
= note: this error originates in the macro `bug` (in Nightly builds, run with -Z macro-backtrace for more info)
error: unexpected expression: `{ let res = ::alloc::fmt::format(format_args!("{0}", "u8")); res }.as_str()`
error: attribute value must be a literal
--> $DIR/key-value-expansion.rs:48:23
|
LL | doc_comment! {format!("{coor}", coor = stringify!($t1)).as_str()}

2
tests/ui/attributes/unused-item-in-attr.rs
View File

@ -1,5 +1,5 @@
#[w = { extern crate alloc; }]
//~^ ERROR unexpected expression: `{
//~^ ERROR attribute value must be a literal
//~| ERROR cannot find attribute `w` in this scope
fn f() {}

4
tests/ui/attributes/unused-item-in-attr.stderr
View File

@ -1,6 +1,4 @@
error: unexpected expression: `{
extern crate alloc;
}`
error: attribute value must be a literal
--> $DIR/unused-item-in-attr.rs:1:7
|
LL | #[w = { extern crate alloc; }]

2
tests/ui/consts/issue-90878-2.rs
View File

@ -1,4 +1,4 @@
#![l=|x|[b;x ]] //~ ERROR unexpected expression: `|x| [b; x]`
#![l=|x|[b;x ]] //~ ERROR attribute value must be a literal
//~^ ERROR cannot find attribute `l` in this scope
// notice the space at the start,

2
tests/ui/consts/issue-90878-2.stderr
View File

@ -1,4 +1,4 @@
error: unexpected expression: `|x| [b; x]`
error: attribute value must be a literal
--> $DIR/issue-90878-2.rs:1:7
|
LL | #![l=|x|[b;x ]]

4
tests/ui/malformed/malformed-interpolated.rs
View File

@ -10,7 +10,7 @@ macro_rules! check {
check!("0"); // OK
check!(0); // OK
check!(0u8); //~ ERROR suffixed literals are not allowed in attributes
check!(-0); //~ ERROR unexpected expression: `-0`
check!(0 + 0); //~ ERROR unexpected expression: `0 + 0`
check!(-0); //~ ERROR attribute value must be a literal
check!(0 + 0); //~ ERROR attribute value must be a literal
fn main() {}

4
tests/ui/malformed/malformed-interpolated.stderr
View File

@ -6,13 +6,13 @@ LL | check!(0u8);
|
= help: instead of using a suffixed literal (`1u8`, `1.0f32`, etc.), use an unsuffixed version (`1`, `1.0`, etc.)
error: unexpected expression: `-0`
error: attribute value must be a literal
--> $DIR/malformed-interpolated.rs:13:8
|
LL | check!(-0);
| ^^
error: unexpected expression: `0 + 0`
error: attribute value must be a literal
--> $DIR/malformed-interpolated.rs:14:8
|
LL | check!(0 + 0);

5
tests/ui/parser/bad-lit-suffixes.rs
View File

@ -28,11 +28,12 @@ fn main() {
}
#[rustc_dummy = "string"suffix]
//~^ ERROR unexpected expression: `"string"suffix`
//~^ ERROR suffixes on string literals are invalid
fn f() {}
#[must_use = "string"suffix]
//~^ ERROR unexpected expression: `"string"suffix`
//~^ ERROR suffixes on string literals are invalid
//~| ERROR malformed `must_use` attribute input
fn g() {}
#[link(name = "string"suffix)]

27
tests/ui/parser/bad-lit-suffixes.stderr
View File

@ -10,26 +10,39 @@ error: suffixes on string literals are invalid
LL | "C"suffix
| ^^^^^^^^^ invalid suffix `suffix`
error: unexpected expression: `"string"suffix`
error: suffixes on string literals are invalid
--> $DIR/bad-lit-suffixes.rs:30:17
|
LL | #[rustc_dummy = "string"suffix]
| ^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^ invalid suffix `suffix`
error: unexpected expression: `"string"suffix`
error: suffixes on string literals are invalid
--> $DIR/bad-lit-suffixes.rs:34:14
|
LL | #[must_use = "string"suffix]
| ^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^ invalid suffix `suffix`
error: malformed `must_use` attribute input
--> $DIR/bad-lit-suffixes.rs:34:1
|
LL | #[must_use = "string"suffix]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
help: the following are the possible correct uses
|
LL | #[must_use = "reason"]
|
LL | #[must_use]
|
error: suffixes on string literals are invalid
--> $DIR/bad-lit-suffixes.rs:38:15
--> $DIR/bad-lit-suffixes.rs:39:15
|
LL | #[link(name = "string"suffix)]
| ^^^^^^^^^^^^^^ invalid suffix `suffix`
error: invalid suffix `suffix` for number literal
--> $DIR/bad-lit-suffixes.rs:42:41
--> $DIR/bad-lit-suffixes.rs:43:41
|
LL | #[rustc_layout_scalar_valid_range_start(0suffix)]
| ^^^^^^^ invalid suffix `suffix`
@ -136,5 +149,5 @@ LL | 1.0e10suffix;
|
= help: valid suffixes are `f32` and `f64`
error: aborting due to 20 previous errors
error: aborting due to 21 previous errors

2
tests/ui/parser/issues/issue-104620.rs
View File

@ -1,4 +1,4 @@
#![feature(rustc_attrs)]
#![rustc_dummy=5z] //~ ERROR unexpected expression: `5z`
#![rustc_dummy=5z] //~ ERROR invalid suffix `z` for number literal
fn main() {}

6
tests/ui/parser/issues/issue-104620.stderr
View File

@ -1,8 +1,10 @@
error: unexpected expression: `5z`
error: invalid suffix `z` for number literal
--> $DIR/issue-104620.rs:3:16
|
LL | #![rustc_dummy=5z]
| ^^
| ^^ invalid suffix `z`
|
= help: the suffix must be one of the numeric types (`u32`, `isize`, `f32`, etc.)
error: aborting due to 1 previous error