use rustc_trait_selection::traits::{self, ObligationCtxt};
use rustc_ty_utils::representability::{self, Representability};
-use std::iter;
use std::ops::ControlFlow;
pub(super) fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Abi) {
}
}
- let mut disr_vals: Vec<Discr<'tcx>> = Vec::with_capacity(vs.len());
- // This tracks the previous variant span (in the loop) incase we need it for diagnostics
- let mut prev_variant_span: Span = DUMMY_SP;
- for ((_, discr), v) in iter::zip(def.discriminants(tcx), vs) {
- // Check for duplicate discriminant values
- if let Some(i) = disr_vals.iter().position(|&x| x.val == discr.val) {
- let variant_did = def.variant(VariantIdx::new(i)).def_id;
- let variant_i_hir_id = tcx.hir().local_def_id_to_hir_id(variant_did.expect_local());
- let variant_i = tcx.hir().expect_variant(variant_i_hir_id);
- let i_span = match variant_i.disr_expr {
- Some(ref expr) => tcx.hir().span(expr.hir_id),
- None => tcx.def_span(variant_did),
- };
- let span = match v.disr_expr {
- Some(ref expr) => tcx.hir().span(expr.hir_id),
- None => v.span,
- };
- let display_discr = format_discriminant_overflow(tcx, v, discr);
- let display_discr_i = format_discriminant_overflow(tcx, variant_i, disr_vals[i]);
- let no_disr = v.disr_expr.is_none();
- let mut err = struct_span_err!(
- tcx.sess,
- sp,
- E0081,
- "discriminant value `{}` assigned more than once",
- discr,
- );
-
- err.span_label(i_span, format!("first assignment of {display_discr_i}"));
- err.span_label(span, format!("second assignment of {display_discr}"));
-
- if no_disr {
- err.span_label(
- prev_variant_span,
- format!(
- "assigned discriminant for `{}` was incremented from this discriminant",
- v.ident
- ),
- );
- }
- err.emit();
- }
-
- disr_vals.push(discr);
- prev_variant_span = v.span;
- }
+ detect_discriminant_duplicate(tcx, def.discriminants(tcx).collect(), vs, sp);
check_representable(tcx, sp, def_id);
check_transparent(tcx, sp, def);
}
-/// In the case that a discriminant is both a duplicate and an overflowing literal,
-/// we insert both the assigned discriminant and the literal it overflowed from into the formatted
-/// output. Otherwise we format the discriminant normally.
-fn format_discriminant_overflow<'tcx>(
+fn detect_discriminant_duplicate<'tcx>(
tcx: TyCtxt<'tcx>,
- variant: &hir::Variant<'_>,
- dis: Discr<'tcx>,
-) -> String {
- if let Some(expr) = &variant.disr_expr {
- let body = &tcx.hir().body(expr.body).value;
- if let hir::ExprKind::Lit(lit) = &body.kind
- && let rustc_ast::LitKind::Int(lit_value, _int_kind) = &lit.node
- && dis.val != *lit_value
- {
- return format!("`{dis}` (overflowed from `{lit_value}`)");
+ mut discrs: Vec<(VariantIdx, Discr<'tcx>)>,
+ vs: &'tcx [hir::Variant<'tcx>],
+ self_span: Span,
+) {
+ let report = |var: &hir::Variant<'_>,
+ dis: Discr<'tcx>,
+ idx: usize,
+ err: &mut DiagnosticBuilder<'_, ErrorGuaranteed>| {
+ let (span, display_discr) = match var.disr_expr {
+ Some(ref expr) => {
+ // In the case the discriminant is both a duplicate and overflowed, let the user know
+ if let hir::ExprKind::Lit(lit) = &tcx.hir().body(expr.body).value.kind
+ && let rustc_ast::LitKind::Int(lit_value, _int_kind) = &lit.node
+ && *lit_value != dis.val
+ {
+ (tcx.hir().span(expr.hir_id), format!("`{dis}` (overflowed from `{lit_value}`)"))
+ } else {
+ (tcx.hir().span(expr.hir_id), format!("`{dis}`"))
+ }
+ }
+ None => {
+ if let Some((n, hir::Variant { span, ident, .. })) =
+ vs[..idx].iter().rev().enumerate().find(|v| v.1.disr_expr.is_some())
+ {
+ let ve_ident = var.ident;
+ let sp = if n > 1 { "variants" } else { "variant" };
+ let n = n + 1;
+
+ err.span_label(
+ *span,
+ format!("discriminant for `{ve_ident}` incremented from this startpoint (`{ident}` + {n} {sp} later => `{ve_ident}` = {dis})"),
+ );
+ }
+
+ (vs[idx].span, format!("`{dis}`"))
+ }
+ };
+
+ err.span_label(span, format!("{display_discr} assigned here"));
+ };
+
+ let mut i = 0;
+ while i < discrs.len() {
+ let hir_var_i_idx = discrs[i].0.index();
+ let hir_var_i = &vs[hir_var_i_idx];
+ let mut error: Option<DiagnosticBuilder<'_, _>> = None;
+
+ let mut o = i + 1;
+ while o < discrs.len() {
+ let hir_var_o_idx = discrs[o].0.index();
+ let hir_var_o = &vs[hir_var_o_idx];
+
+ if discrs[i].1.val == discrs[o].1.val {
+ let err = error.get_or_insert_with(|| {
+ let mut ret = struct_span_err!(
+ tcx.sess,
+ self_span,
+ E0081,
+ "discriminant value `{}` assigned more than once",
+ discrs[i].1,
+ );
+
+ report(hir_var_i, discrs[i].1, hir_var_i_idx, &mut ret);
+
+ ret
+ });
+
+ report(hir_var_o, discrs[o].1, hir_var_o_idx, err);
+
+ discrs[o] = *discrs.last().unwrap();
+ discrs.pop();
+ } else {
+ o += 1;
+ }
}
- }
- format!("`{dis}`")
+ if let Some(mut e) = error {
+ e.emit();
+ }
+
+ i += 1;
+ }
}
pub(super) fn check_type_params_are_used<'tcx>(
enum Enum {
//~^ ERROR discriminant value `3` assigned more than once
P = 3,
- //~^ NOTE first assignment of `3`
+ //~^ NOTE `3` assigned here
X = 3,
- //~^ NOTE second assignment of `3`
+ //~^ NOTE `3` assigned here
Y = 5
}
enum EnumOverflowRepr {
//~^ ERROR discriminant value `1` assigned more than once
P = 257,
- //~^ NOTE first assignment of `1` (overflowed from `257`)
+ //~^ NOTE `1` (overflowed from `257`) assigned here
X = 513,
- //~^ NOTE second assignment of `1` (overflowed from `513`)
+ //~^ NOTE `1` (overflowed from `513`) assigned here
}
#[repr(i8)]
enum NegDisEnum {
//~^ ERROR discriminant value `-1` assigned more than once
First = -1,
- //~^ NOTE first assignment of `-1`
+ //~^ NOTE `-1` assigned here
Second = -2,
- //~^ NOTE assigned discriminant for `Last` was incremented from this discriminant
+ //~^ NOTE discriminant for `Last` incremented from this startpoint (`Second` + 1 variant later => `Last` = -1)
Last,
- //~^ NOTE second assignment of `-1`
+ //~^ NOTE `-1` assigned here
+}
+
+#[repr(i32)]
+enum MultipleDuplicates {
+ //~^ ERROR discriminant value `0` assigned more than once
+ V0,
+ //~^ NOTE `0` assigned here
+ V1 = 0,
+ //~^ NOTE `0` assigned here
+ V2,
+ V3,
+ V4 = 0,
+ //~^ NOTE `0` assigned here
+ V5 = -2,
+ //~^ NOTE discriminant for `V7` incremented from this startpoint (`V5` + 2 variant later => `V7` = 0)
+ V6,
+ V7,
+ //~^ NOTE `0` assigned here
}
fn main() {
| ^^^^^^^^^
LL |
LL | P = 3,
- | - first assignment of `3`
+ | - `3` assigned here
LL |
LL | X = 3,
- | - second assignment of `3`
+ | - `3` assigned here
error[E0081]: discriminant value `1` assigned more than once
--> $DIR/E0081.rs:11:1
| ^^^^^^^^^^^^^^^^^^^^^
LL |
LL | P = 257,
- | --- first assignment of `1` (overflowed from `257`)
+ | --- `1` (overflowed from `257`) assigned here
LL |
LL | X = 513,
- | --- second assignment of `1` (overflowed from `513`)
+ | --- `1` (overflowed from `513`) assigned here
error[E0081]: discriminant value `-1` assigned more than once
--> $DIR/E0081.rs:20:1
| ^^^^^^^^^^^^^^^
LL |
LL | First = -1,
- | -- first assignment of `-1`
+ | -- `-1` assigned here
LL |
LL | Second = -2,
- | ----------- assigned discriminant for `Last` was incremented from this discriminant
+ | ----------- discriminant for `Last` incremented from this startpoint (`Second` + 1 variant later => `Last` = -1)
LL |
LL | Last,
- | ---- second assignment of `-1`
+ | ---- `-1` assigned here
-error: aborting due to 3 previous errors
+error[E0081]: discriminant value `0` assigned more than once
+ --> $DIR/E0081.rs:31:1
+ |
+LL | enum MultipleDuplicates {
+ | ^^^^^^^^^^^^^^^^^^^^^^^
+LL |
+LL | V0,
+ | -- `0` assigned here
+LL |
+LL | V1 = 0,
+ | - `0` assigned here
+...
+LL | V4 = 0,
+ | - `0` assigned here
+LL |
+LL | V5 = -2,
+ | ------- discriminant for `V7` incremented from this startpoint (`V5` + 2 variant later => `V7` = 0)
+...
+LL | V7,
+ | -- `0` assigned here
+
+error: aborting due to 4 previous errors
For more information about this error, try `rustc --explain E0081`.
projects / rust.git / commitdiff