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Rollup merge of #137565 - compiler-errors:macro-ex, r=estebank

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Try to point of macro expansion from resolver and method errors if it involves macro var

In the case that a macro caller passes an identifier into a macro generating a path or method expression, point out that identifier in the context of the *macro* so it's a bit more clear how the macro is involved in causing the error.

r? ``````````@estebank`````````` or reassign
This commit is contained in:
Michael Goulet 2025-03-06 12:22:13 -05:00 • committed by GitHub
commit aab7b145d0
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GPG key ID: B5690EEEBB952194
17 changed files with 225 additions and 15 deletions
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2
compiler/rustc_hir_analysis/messages.ftl
View file

@ -617,6 +617,8 @@ hir_analysis_variances_of = {$variances}
hir_analysis_where_clause_on_main = `main` function is not allowed to have a `where` clause
.label = `main` cannot have a `where` clause
hir_analysis_within_macro = due to this macro variable
hir_analysis_wrong_number_of_generic_arguments_to_intrinsic =
intrinsic has wrong number of {$descr} parameters: found {$found}, expected {$expected}
.label = expected {$expected} {$descr} {$expected ->

2
compiler/rustc_hir_analysis/src/errors.rs
View file

@ -82,6 +82,8 @@ pub(crate) struct AssocItemNotFound<'a> {
pub label: Option<AssocItemNotFoundLabel<'a>>,
#[subdiagnostic]
pub sugg: Option<AssocItemNotFoundSugg<'a>>,
#[label(hir_analysis_within_macro)]
pub within_macro_span: Option<Span>,
}
#[derive(Subdiagnostic)]

3
compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
View file

@ -151,6 +151,9 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
qself: &qself_str,
label: None,
sugg: None,
// Try to get the span of the identifier within the path's syntax context
// (if that's different).
within_macro_span: assoc_name.span.within_macro(span, tcx.sess.source_map()),
};
if is_dummy {

35
compiler/rustc_hir_typeck/src/expr.rs
View file

@ -3069,7 +3069,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
"ban_nonexisting_field: field={:?}, base={:?}, expr={:?}, base_ty={:?}",
ident, base, expr, base_ty
);
let mut err = self.no_such_field_err(ident, base_ty, base.hir_id);
let mut err = self.no_such_field_err(ident, base_ty, expr);
match *base_ty.peel_refs().kind() {
ty::Array(_, len) => {
@ -3282,18 +3282,27 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
);
}
fn no_such_field_err(&self, field: Ident, expr_t: Ty<'tcx>, id: HirId) -> Diag<'_> {
fn no_such_field_err(
&self,
field: Ident,
base_ty: Ty<'tcx>,
expr: &hir::Expr<'tcx>,
) -> Diag<'_> {
let span = field.span;
debug!("no_such_field_err(span: {:?}, field: {:?}, expr_t: {:?})", span, field, expr_t);
debug!("no_such_field_err(span: {:?}, field: {:?}, expr_t: {:?})", span, field, base_ty);
let mut err = self.dcx().create_err(NoFieldOnType { span, ty: expr_t, field });
if expr_t.references_error() {
let mut err = self.dcx().create_err(NoFieldOnType { span, ty: base_ty, field });
if base_ty.references_error() {
err.downgrade_to_delayed_bug();
}
if let Some(within_macro_span) = span.within_macro(expr.span, self.tcx.sess.source_map()) {
err.span_label(within_macro_span, "due to this macro variable");
}
// try to add a suggestion in case the field is a nested field of a field of the Adt
let mod_id = self.tcx.parent_module(id).to_def_id();
let (ty, unwrap) = if let ty::Adt(def, args) = expr_t.kind()
let mod_id = self.tcx.parent_module(expr.hir_id).to_def_id();
let (ty, unwrap) = if let ty::Adt(def, args) = base_ty.kind()
&& (self.tcx.is_diagnostic_item(sym::Result, def.did())
|| self.tcx.is_diagnostic_item(sym::Option, def.did()))
&& let Some(arg) = args.get(0)
@ -3301,10 +3310,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
{
(ty, "unwrap().")
} else {
(expr_t, "")
(base_ty, "")
};
for (found_fields, args) in
self.get_field_candidates_considering_privacy_for_diag(span, ty, mod_id, id)
self.get_field_candidates_considering_privacy_for_diag(span, ty, mod_id, expr.hir_id)
{
let field_names = found_fields.iter().map(|field| field.name).collect::<Vec<_>>();
let mut candidate_fields: Vec<_> = found_fields
@ -3317,7 +3326,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
args,
vec![],
mod_id,
id,
expr.hir_id,
)
})
.map(|mut field_path| {
@ -3328,7 +3337,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
candidate_fields.sort();
let len = candidate_fields.len();
if len > 0 {
// Don't suggest `.field` if the base expr is from a different
// syntax context than the field.
if len > 0 && expr.span.eq_ctxt(field.span) {
err.span_suggestions(
field.span.shrink_to_lo(),
format!(
@ -3963,7 +3974,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
_ => (),
};
self.no_such_field_err(field, container, expr.hir_id).emit();
self.no_such_field_err(field, container, expr).emit();
break;
}

24
compiler/rustc_hir_typeck/src/method/suggest.rs
View file

@ -158,7 +158,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
self.typeck_results.borrow_mut().used_trait_imports.insert(import_id);
}
let (span, sugg_span, source, item_name, args) = match self.tcx.hir_node(call_id) {
let (span, expr_span, source, item_name, args) = match self.tcx.hir_node(call_id) {
hir::Node::Expr(&hir::Expr {
kind: hir::ExprKind::MethodCall(segment, rcvr, args, _),
span,
@ -194,6 +194,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
node => unreachable!("{node:?}"),
};
// Try to get the span of the identifier within the expression's syntax context
// (if that's different).
let within_macro_span = span.within_macro(expr_span, self.tcx.sess.source_map());
// Avoid suggestions when we don't know what's going on.
if let Err(guar) = rcvr_ty.error_reported() {
return guar;
@ -207,10 +211,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
call_id,
source,
args,
sugg_span,
expr_span,
&mut no_match_data,
expected,
trait_missing_method,
within_macro_span,
),
MethodError::Ambiguity(mut sources) => {
@ -221,6 +226,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
"multiple applicable items in scope"
);
err.span_label(item_name.span, format!("multiple `{item_name}` found"));
if let Some(within_macro_span) = within_macro_span {
err.span_label(within_macro_span, "due to this macro variable");
}
self.note_candidates_on_method_error(
rcvr_ty,
@ -230,7 +238,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
span,
&mut err,
&mut sources,
Some(sugg_span),
Some(expr_span),
);
err.emit()
}
@ -252,6 +260,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
.span_if_local(def_id)
.unwrap_or_else(|| self.tcx.def_span(def_id));
err.span_label(sp, format!("private {kind} defined here"));
if let Some(within_macro_span) = within_macro_span {
err.span_label(within_macro_span, "due to this macro variable");
}
self.suggest_valid_traits(&mut err, item_name, out_of_scope_traits, true);
err.emit()
}
@ -268,6 +279,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
if !needs_mut {
err.span_label(bound_span, "this has a `Sized` requirement");
}
if let Some(within_macro_span) = within_macro_span {
err.span_label(within_macro_span, "due to this macro variable");
}
if !candidates.is_empty() {
let help = format!(
"{an}other candidate{s} {were} found in the following trait{s}",
@ -581,6 +595,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
no_match_data: &mut NoMatchData<'tcx>,
expected: Expectation<'tcx>,
trait_missing_method: bool,
within_macro_span: Option<Span>,
) -> ErrorGuaranteed {
let mode = no_match_data.mode;
let tcx = self.tcx;
@ -721,6 +736,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
if tcx.sess.source_map().is_multiline(sugg_span) {
err.span_label(sugg_span.with_hi(span.lo()), "");
}
if let Some(within_macro_span) = within_macro_span {
err.span_label(within_macro_span, "due to this macro variable");
}
if short_ty_str.len() < ty_str.len() && ty_str.len() > 10 {
ty_str = short_ty_str;

8
compiler/rustc_resolve/src/late/diagnostics.rs
View file

@ -429,6 +429,14 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
let mut err = self.r.dcx().struct_span_err(base_error.span, base_error.msg.clone());
err.code(code);
// Try to get the span of the identifier within the path's syntax context
// (if that's different).
if let Some(within_macro_span) =
base_error.span.within_macro(span, self.r.tcx.sess.source_map())
{
err.span_label(within_macro_span, "due to this macro variable");
}
self.detect_missing_binding_available_from_pattern(&mut err, path, following_seg);
self.suggest_at_operator_in_slice_pat_with_range(&mut err, path);
self.suggest_swapping_misplaced_self_ty_and_trait(&mut err, source, res, base_error.span);

31
compiler/rustc_span/src/lib.rs
View file

@ -1057,6 +1057,37 @@ impl Span {
}
}
/// Returns the `Span` within the syntax context of "within". This is useful when
/// "self" is an expansion from a macro variable, since this can be used for
/// providing extra macro expansion context for certain errors.
///
/// ```text
/// macro_rules! m {
/// ($ident:ident) => { ($ident,) }
/// }
///
/// m!(outer_ident);
/// ```
///
/// If "self" is the span of the outer_ident, and "within" is the span of the `($ident,)`
/// expr, then this will return the span of the `$ident` macro variable.
pub fn within_macro(self, within: Span, sm: &SourceMap) -> Option<Span> {
match Span::prepare_to_combine(self, within) {
// Only return something if it doesn't overlap with the original span,
// and the span isn't "imported" (i.e. from unavailable sources).
// FIXME: This does limit the usefulness of the error when the macro is
// from a foreign crate; we could also take into account `-Zmacro-backtrace`,
// which doesn't redact this span (but that would mean passing in even more
// args to this function, lol).
Ok((self_, _, parent))
if self_.hi < self.lo() || self.hi() < self_.lo && !sm.is_imported(within) =>
{
Some(Span::new(self_.lo, self_.hi, self_.ctxt, parent))
}
_ => None,
}
}
pub fn from_inner(self, inner: InnerSpan) -> Span {
let span = self.data();
Span::new(

23
tests/ui/associated-types/ident-from-macro-expansion.rs Normal file
View file

@ -0,0 +1,23 @@
trait Trait {}
impl Trait for () {}
macro_rules! fully_qualified {
($id:ident) => {
<() as Trait>::$id
}
}
macro_rules! type_dependent {
($t:ident, $id:ident) => {
T::$id
}
}
fn t<T: Trait>() {
let x: fully_qualified!(Assoc);
//~^ ERROR cannot find associated type `Assoc` in trait `Trait`
let x: type_dependent!(T, Assoc);
//~^ ERROR associated type `Assoc` not found for `T`
}
fn main() {}

22
tests/ui/associated-types/ident-from-macro-expansion.stderr Normal file
View file

@ -0,0 +1,22 @@
error[E0576]: cannot find associated type `Assoc` in trait `Trait`
--> $DIR/ident-from-macro-expansion.rs:17:29
|
LL | <() as Trait>::$id
| --- due to this macro variable
...
LL | let x: fully_qualified!(Assoc);
| ^^^^^ not found in `Trait`
error[E0220]: associated type `Assoc` not found for `T`
--> $DIR/ident-from-macro-expansion.rs:19:31
|
LL | T::$id
| --- due to this macro variable
...
LL | let x: type_dependent!(T, Assoc);
| ^^^^^ associated type `Assoc` not found
error: aborting due to 2 previous errors
Some errors have detailed explanations: E0220, E0576.
For more information about an error, try `rustc --explain E0220`.

6
tests/ui/hygiene/generate-mod.stderr
View file

@ -1,12 +1,18 @@
error[E0412]: cannot find type `FromOutside` in this scope
--> $DIR/generate-mod.rs:35:13
|
LL | type A = $FromOutside;
| ------------ due to this macro variable
...
LL | genmod!(FromOutside, Outer);
| ^^^^^^^^^^^ not found in this scope
error[E0412]: cannot find type `Outer` in this scope
--> $DIR/generate-mod.rs:35:26
|
LL | struct $Outer;
| ------ due to this macro variable
...
LL | genmod!(FromOutside, Outer);
| ^^^^^ not found in this scope

6
tests/ui/hygiene/globs.stderr
View file

@ -50,6 +50,9 @@ error[E0425]: cannot find function `f` in this scope
LL | n!(f);
| ----- in this macro invocation
...
LL | $j();
| -- due to this macro variable
...
LL | n!(f);
| ^ not found in this scope
|
@ -63,6 +66,9 @@ error[E0425]: cannot find function `f` in this scope
LL | n!(f);
| ----- in this macro invocation
...
LL | $j();
| -- due to this macro variable
...
LL | f
| ^ not found in this scope
|

3
tests/ui/macros/macro-parameter-span.stderr
View file

@ -1,6 +1,9 @@
error[E0425]: cannot find value `x` in this scope
--> $DIR/macro-parameter-span.rs:11:9
|
LL | $id
| --- due to this macro variable
...
LL | x
| ^ not found in this scope

3
tests/ui/macros/rfc-3086-metavar-expr/syntax-errors.stderr
View file

@ -338,6 +338,9 @@ LL | no_curly__no_rhs_dollar__no_round!(a);
error[E0425]: cannot find value `a` in this scope
--> $DIR/syntax-errors.rs:152:37
|
LL | ( $i:ident ) => { count($i) };
| -- due to this macro variable
...
LL | no_curly__rhs_dollar__no_round!(a);
| ^ not found in this scope

18
tests/ui/methods/ident-from-macro-expansion.rs Normal file
View file

@ -0,0 +1,18 @@
macro_rules! dot {
($id:ident) => {
().$id();
}
}
macro_rules! dispatch {
($id:ident) => {
<()>::$id();
}
}
fn main() {
dot!(hello);
//~^ ERROR no method named `hello` found for unit type `()` in the current scope
dispatch!(hello);
//~^ ERROR no function or associated item named `hello` found for unit type `()` in the current scope
}

21
tests/ui/methods/ident-from-macro-expansion.stderr Normal file
View file

@ -0,0 +1,21 @@
error[E0599]: no method named `hello` found for unit type `()` in the current scope
--> $DIR/ident-from-macro-expansion.rs:14:10
|
LL | ().$id();
| --- due to this macro variable
...
LL | dot!(hello);
| ^^^^^ method not found in `()`
error[E0599]: no function or associated item named `hello` found for unit type `()` in the current scope
--> $DIR/ident-from-macro-expansion.rs:16:15
|
LL | <()>::$id();
| --- due to this macro variable
...
LL | dispatch!(hello);
| ^^^^^ function or associated item not found in `()`
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0599`.

19
tests/ui/structs/ident-from-macro-expansion.rs Normal file
View file

@ -0,0 +1,19 @@
struct Foo {
inner: Inner,
}
struct Inner {
y: i32,
}
macro_rules! access {
($expr:expr, $ident:ident) => {
$expr.$ident
}
}
fn main() {
let k = Foo { inner: Inner { y: 0 } };
access!(k, y);
//~^ ERROR no field `y` on type `Foo`
}

14
tests/ui/structs/ident-from-macro-expansion.stderr Normal file
View file

@ -0,0 +1,14 @@
error[E0609]: no field `y` on type `Foo`
--> $DIR/ident-from-macro-expansion.rs:17:16
|
LL | $expr.$ident
| ------ due to this macro variable
...
LL | access!(k, y);
| ^ unknown field
|
= note: available field is: `inner`
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0609`.