Better error for non const PartialEq call generated by match

Author: fee1-dead

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -14,7 +14,7 @@ use rustc_infer::traits::ObligationCause;
 use rustc_middle::hir::nested_filter::OnlyBodies;
 use rustc_middle::mir::tcx::PlaceTy;
 use rustc_middle::mir::{
-    self, AggregateKind, BindingForm, BorrowKind, ClearCrossCrate, ConstraintCategory,
+    self, AggregateKind, BindingForm, BorrowKind, CallSource, ClearCrossCrate, ConstraintCategory,
     FakeReadCause, LocalDecl, LocalInfo, LocalKind, Location, Operand, Place, PlaceRef,
     ProjectionElem, Rvalue, Statement, StatementKind, Terminator, TerminatorKind, VarBindingForm,
 };
@@ -2579,7 +2579,10 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
     fn explain_deref_coercion(&mut self, loan: &BorrowData<'tcx>, err: &mut Diagnostic) {
         let tcx = self.infcx.tcx;
         if let (
-            Some(Terminator { kind: TerminatorKind::Call { from_hir_call: false, .. }, .. }),
+            Some(Terminator {
+                kind: TerminatorKind::Call { call_source: CallSource::OverloadedOperator, .. },
+                ..
+            }),
             Some((method_did, method_substs)),
         ) = (
             &self.body[loan.reserve_location.block].terminator,

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -6,8 +6,8 @@ use rustc_hir::intravisit::Visitor;
 use rustc_index::IndexSlice;
 use rustc_infer::infer::NllRegionVariableOrigin;
 use rustc_middle::mir::{
-    Body, CastKind, ConstraintCategory, FakeReadCause, Local, LocalInfo, Location, Operand, Place,
-    Rvalue, Statement, StatementKind, TerminatorKind,
+    Body, CallSource, CastKind, ConstraintCategory, FakeReadCause, Local, LocalInfo, Location,
+    Operand, Place, Rvalue, Statement, StatementKind, TerminatorKind,
 };
 use rustc_middle::ty::adjustment::PointerCast;
 use rustc_middle::ty::{self, RegionVid, TyCtxt};
@@ -494,7 +494,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 } else if self.was_captured_by_trait_object(borrow) {
                     LaterUseKind::TraitCapture
                 } else if location.statement_index == block.statements.len() {
-                    if let TerminatorKind::Call { func, from_hir_call: true, .. } =
+                    if let TerminatorKind::Call { func, call_source: CallSource::Normal, .. } =
                         &block.terminator().kind
                     {
                         // Just point to the function, to reduce the chance of overlapping spans.

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -13,8 +13,9 @@ use rustc_index::IndexSlice;
 use rustc_infer::infer::LateBoundRegionConversionTime;
 use rustc_middle::mir::tcx::PlaceTy;
 use rustc_middle::mir::{
-    AggregateKind, Constant, FakeReadCause, Local, LocalInfo, LocalKind, Location, Operand, Place,
-    PlaceRef, ProjectionElem, Rvalue, Statement, StatementKind, Terminator, TerminatorKind,
+    AggregateKind, CallSource, Constant, FakeReadCause, Local, LocalInfo, LocalKind, Location,
+    Operand, Place, PlaceRef, ProjectionElem, Rvalue, Statement, StatementKind, Terminator,
+    TerminatorKind,
 };
 use rustc_middle::ty::print::Print;
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
@@ -414,7 +415,12 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     if !is_terminator {
                         continue;
                     } else if let Some(Terminator {
-                        kind: TerminatorKind::Call { func, from_hir_call: false, .. },
+                        kind:
+                            TerminatorKind::Call {
+                                func,
+                                call_source: CallSource::OverloadedOperator,
+                                ..
+                            },
                         ..
                     }) = &bbd.terminator
                     {
@@ -839,7 +845,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         debug!("move_spans: target_temp = {:?}", target_temp);
 
         if let Some(Terminator {
-            kind: TerminatorKind::Call { fn_span, from_hir_call, .. }, ..
+            kind: TerminatorKind::Call { fn_span, call_source, .. }, ..
         }) = &self.body[location.block].terminator
         {
             let Some((method_did, method_substs)) =
@@ -859,7 +865,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 method_did,
                 method_substs,
                 *fn_span,
-                *from_hir_call,
+                call_source.from_hir_call(),
                 Some(self.infcx.tcx.fn_arg_names(method_did)[0]),
             );
 

compiler/rustc_borrowck/src/invalidation.rs

@@ -128,7 +128,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
                 destination,
                 target: _,
                 unwind: _,
-                from_hir_call: _,
+                call_source: _,
                 fn_span: _,
             } => {
                 self.consume_operand(location, func);

compiler/rustc_borrowck/src/lib.rs

@@ -710,7 +710,7 @@ impl<'cx, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx, R> for MirBorro
                 destination,
                 target: _,
                 unwind: _,
-                from_hir_call: _,
+                call_source: _,
                 fn_span: _,
             } => {
                 self.consume_operand(loc, (func, span), flow_state);

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1370,7 +1370,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 }
                 // FIXME: check the values
             }
-            TerminatorKind::Call { func, args, destination, from_hir_call, target, .. } => {
+            TerminatorKind::Call { func, args, destination, call_source, target, .. } => {
                 self.check_operand(func, term_location);
                 for arg in args {
                     self.check_operand(arg, term_location);
@@ -1444,7 +1444,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                         .add_element(region_vid, term_location);
                 }
 
-                self.check_call_inputs(body, term, &sig, args, term_location, *from_hir_call);
+                self.check_call_inputs(body, term, &sig, args, term_location, *call_source);
             }
             TerminatorKind::Assert { cond, msg, .. } => {
                 self.check_operand(cond, term_location);
@@ -1571,7 +1571,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         sig: &ty::FnSig<'tcx>,
         args: &[Operand<'tcx>],
         term_location: Location,
-        from_hir_call: bool,
+        call_source: CallSource,
     ) {
         debug!("check_call_inputs({:?}, {:?})", sig, args);
         if args.len() < sig.inputs().len() || (args.len() > sig.inputs().len() && !sig.c_variadic) {
@@ -1589,7 +1589,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             let op_arg_ty = op_arg.ty(body, self.tcx());
 
             let op_arg_ty = self.normalize(op_arg_ty, term_location);
-            let category = if from_hir_call {
+            let category = if call_source.from_hir_call() {
                 ConstraintCategory::CallArgument(self.infcx.tcx.erase_regions(func_ty))
             } else {
                 ConstraintCategory::Boring

compiler/rustc_codegen_cranelift/src/base.rs

@@ -421,7 +421,7 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
                 target,
                 fn_span,
                 unwind: _,
-                from_hir_call: _,
+                call_source: _,
             } => {
                 fx.tcx.prof.generic_activity("codegen call").run(|| {
                     crate::abi::codegen_terminator_call(

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -1280,7 +1280,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 destination,
                 target,
                 unwind,
-                from_hir_call: _,
+                call_source: _,
                 fn_span,
             } => self.codegen_call_terminator(
                 helper,

compiler/rustc_const_eval/messages.ftl

@@ -210,6 +210,9 @@ const_eval_long_running =
     .label = the const evaluator is currently interpreting this expression
     .help = the constant being evaluated
 
+const_eval_match_eq_non_const = cannot match on `{$ty}` in {const_eval_const_context}s
+    .note = `{$ty}` cannot be compared in compile-time, and therefore cannot be used in `match`es
+
 const_eval_max_num_nodes_in_const = maximum number of nodes exceeded in constant {$global_const_id}
 
 const_eval_memory_access_test = memory access failed

compiler/rustc_const_eval/src/errors.rs

@@ -271,6 +271,18 @@ pub struct RawBytesNote {
     pub bytes: String,
 }
 
+// FIXME(fee1-dead) do not use stringly typed `ConstContext`
+
+#[derive(Diagnostic)]
+#[diag(const_eval_match_eq_non_const, code = "E0015")]
+#[note]
+pub struct NonConstMatchEq<'tcx> {
+    #[primary_span]
+    pub span: Span,
+    pub ty: Ty<'tcx>,
+    pub kind: ConstContext,
+}
+
 #[derive(Diagnostic)]
 #[diag(const_eval_for_loop_into_iter_non_const, code = "E0015")]
 pub struct NonConstForLoopIntoIter<'tcx> {