Auto merge of #105531 - matthiaskrgr:rollup-7y7zbgl, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #104460 (Migrate parts of `rustc_expand` to session diagnostics)
 - #105192 (Point at LHS on binop type err if relevant)
 - #105234 (Remove unneeded field from `SwitchTargets`)
 - #105239 (Avoid heap allocation when truncating thread names)
 - #105410 (Consider `parent_count` for const param defaults)
 - #105482 (Fix invalid codegen during debuginfo lowering)

Failed merges:

 - #105411 (Introduce `with_forced_trimmed_paths`)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_borrowck/src/invalidation.rs

@@ -106,7 +106,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
         self.check_activations(location);
 
         match &terminator.kind {
-            TerminatorKind::SwitchInt { discr, switch_ty: _, targets: _ } => {
+            TerminatorKind::SwitchInt { discr, targets: _ } => {
                 self.consume_operand(location, discr);
             }
             TerminatorKind::Drop { place: drop_place, target: _, unwind: _ } => {

compiler/rustc_borrowck/src/lib.rs

@@ -644,7 +644,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx
         self.check_activations(loc, span, flow_state);
 
         match &term.kind {
-            TerminatorKind::SwitchInt { discr, switch_ty: _, targets: _ } => {
+            TerminatorKind::SwitchInt { discr, targets: _ } => {
                 self.consume_operand(loc, (discr, span), flow_state);
             }
             TerminatorKind::Drop { place, target: _, unwind: _ } => {

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1360,25 +1360,10 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                     );
                 }
             }
-            TerminatorKind::SwitchInt { discr, switch_ty, .. } => {
+            TerminatorKind::SwitchInt { discr, .. } => {
                 self.check_operand(discr, term_location);
 
-                let discr_ty = discr.ty(body, tcx);
-                if let Err(terr) = self.sub_types(
-                    discr_ty,
-                    *switch_ty,
-                    term_location.to_locations(),
-                    ConstraintCategory::Assignment,
-                ) {
-                    span_mirbug!(
-                        self,
-                        term,
-                        "bad SwitchInt ({:?} on {:?}): {:?}",
-                        switch_ty,
-                        discr_ty,
-                        terr
-                    );
-                }
+                let switch_ty = discr.ty(body, tcx);
                 if !switch_ty.is_integral() && !switch_ty.is_char() && !switch_ty.is_bool() {
                     span_mirbug!(self, term, "bad SwitchInt discr ty {:?}", switch_ty);
                 }

compiler/rustc_builtin_macros/src/concat.rs

@@ -11,7 +11,7 @@ pub fn expand_concat(
     sp: rustc_span::Span,
     tts: TokenStream,
 ) -> Box<dyn base::MacResult + 'static> {
-    let Some(es) = base::get_exprs_from_tts(cx, sp, tts) else {
+    let Some(es) = base::get_exprs_from_tts(cx, tts) else {
         return DummyResult::any(sp);
     };
     let mut accumulator = String::new();

compiler/rustc_builtin_macros/src/concat_bytes.rs

@@ -137,7 +137,7 @@ pub fn expand_concat_bytes(
     sp: rustc_span::Span,
     tts: TokenStream,
 ) -> Box<dyn base::MacResult + 'static> {
-    let Some(es) = base::get_exprs_from_tts(cx, sp, tts) else {
+    let Some(es) = base::get_exprs_from_tts(cx, tts) else {
         return DummyResult::any(sp);
     };
     let mut accumulator = Vec::new();

compiler/rustc_builtin_macros/src/env.rs

@@ -52,7 +52,7 @@ pub fn expand_env<'cx>(
     sp: Span,
     tts: TokenStream,
 ) -> Box<dyn base::MacResult + 'cx> {
-    let mut exprs = match get_exprs_from_tts(cx, sp, tts) {
+    let mut exprs = match get_exprs_from_tts(cx, tts) {
         Some(exprs) if exprs.is_empty() => {
             cx.span_err(sp, "env! takes 1 or 2 arguments");
             return DummyResult::any(sp);

compiler/rustc_codegen_cranelift/src/base.rs

@@ -372,8 +372,10 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
                 }
             }
 
-            TerminatorKind::SwitchInt { discr, switch_ty, targets } => {
-                let discr = codegen_operand(fx, discr).load_scalar(fx);
+            TerminatorKind::SwitchInt { discr, targets } => {
+                let discr = codegen_operand(fx, discr);
+                let switch_ty = discr.layout().ty;
+                let discr = discr.load_scalar(fx);
 
                 let use_bool_opt = switch_ty.kind() == fx.tcx.types.bool.kind()
                     || (targets.iter().count() == 1 && targets.iter().next().unwrap().0 == 0);

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -307,12 +307,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         helper: TerminatorCodegenHelper<'tcx>,
         bx: &mut Bx,
         discr: &mir::Operand<'tcx>,
-        switch_ty: Ty<'tcx>,
         targets: &SwitchTargets,
     ) {
         let discr = self.codegen_operand(bx, &discr);
-        // `switch_ty` is redundant, sanity-check that.
-        assert_eq!(discr.layout.ty, switch_ty);
+        let switch_ty = discr.layout.ty;
         let mut target_iter = targets.iter();
         if target_iter.len() == 1 {
             // If there are two targets (one conditional, one fallback), emit `br` instead of
@@ -1293,8 +1291,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 helper.funclet_br(self, bx, target, mergeable_succ())
             }
 
-            mir::TerminatorKind::SwitchInt { ref discr, switch_ty, ref targets } => {
-                self.codegen_switchint_terminator(helper, bx, discr, switch_ty, targets);
+            mir::TerminatorKind::SwitchInt { ref discr, ref targets } => {
+                self.codegen_switchint_terminator(helper, bx, discr, targets);
                 MergingSucc::False
             }
 

compiler/rustc_codegen_ssa/src/mir/debuginfo.rs

@@ -3,12 +3,12 @@ use rustc_index::vec::IndexVec;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::mir;
 use rustc_middle::ty;
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
 use rustc_session::config::DebugInfo;
 use rustc_span::symbol::{kw, Symbol};
 use rustc_span::{BytePos, Span};
-use rustc_target::abi::Abi;
-use rustc_target::abi::Size;
+use rustc_target::abi::{Abi, Size, VariantIdx};
 
 use super::operand::{OperandRef, OperandValue};
 use super::place::PlaceRef;
@@ -76,6 +76,106 @@ impl<'tcx, S: Copy, L: Copy> DebugScope<S, L> {
     }
 }
 
+trait DebugInfoOffsetLocation<'tcx, Bx> {
+    fn deref(&self, bx: &mut Bx) -> Self;
+    fn layout(&self) -> TyAndLayout<'tcx>;
+    fn project_field(&self, bx: &mut Bx, field: mir::Field) -> Self;
+    fn downcast(&self, bx: &mut Bx, variant: VariantIdx) -> Self;
+}
+
+impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> DebugInfoOffsetLocation<'tcx, Bx>
+    for PlaceRef<'tcx, Bx::Value>
+{
+    fn deref(&self, bx: &mut Bx) -> Self {
+        bx.load_operand(*self).deref(bx.cx())
+    }
+
+    fn layout(&self) -> TyAndLayout<'tcx> {
+        self.layout
+    }
+
+    fn project_field(&self, bx: &mut Bx, field: mir::Field) -> Self {
+        PlaceRef::project_field(*self, bx, field.index())
+    }
+
+    fn downcast(&self, bx: &mut Bx, variant: VariantIdx) -> Self {
+        self.project_downcast(bx, variant)
+    }
+}
+
+impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> DebugInfoOffsetLocation<'tcx, Bx>
+    for TyAndLayout<'tcx>
+{
+    fn deref(&self, bx: &mut Bx) -> Self {
+        bx.cx().layout_of(
+            self.ty.builtin_deref(true).unwrap_or_else(|| bug!("cannot deref `{}`", self.ty)).ty,
+        )
+    }
+
+    fn layout(&self) -> TyAndLayout<'tcx> {
+        *self
+    }
+
+    fn project_field(&self, bx: &mut Bx, field: mir::Field) -> Self {
+        self.field(bx.cx(), field.index())
+    }
+
+    fn downcast(&self, bx: &mut Bx, variant: VariantIdx) -> Self {
+        self.for_variant(bx.cx(), variant)
+    }
+}
+
+struct DebugInfoOffset<T> {
+    /// Offset from the `base` used to calculate the debuginfo offset.
+    direct_offset: Size,
+    /// Each offset in this vector indicates one level of indirection from the base or previous
+    /// indirect offset plus a dereference.
+    indirect_offsets: Vec<Size>,
+    /// The final location debuginfo should point to.
+    result: T,
+}
+
+fn calculate_debuginfo_offset<
+    'a,
+    'tcx,
+    Bx: BuilderMethods<'a, 'tcx>,
+    L: DebugInfoOffsetLocation<'tcx, Bx>,
+>(
+    bx: &mut Bx,
+    local: mir::Local,
+    var: &PerLocalVarDebugInfo<'tcx, Bx::DIVariable>,
+    base: L,
+) -> DebugInfoOffset<L> {
+    let mut direct_offset = Size::ZERO;
+    // FIXME(eddyb) use smallvec here.
+    let mut indirect_offsets = vec![];
+    let mut place = base;
+
+    for elem in &var.projection[..] {
+        match *elem {
+            mir::ProjectionElem::Deref => {
+                indirect_offsets.push(Size::ZERO);
+                place = place.deref(bx);
+            }
+            mir::ProjectionElem::Field(field, _) => {
+                let offset = indirect_offsets.last_mut().unwrap_or(&mut direct_offset);
+                *offset += place.layout().fields.offset(field.index());
+                place = place.project_field(bx, field);
+            }
+            mir::ProjectionElem::Downcast(_, variant) => {
+                place = place.downcast(bx, variant);
+            }
+            _ => span_bug!(
+                var.source_info.span,
+                "unsupported var debuginfo place `{:?}`",
+                mir::Place { local, projection: var.projection },
+            ),
+        }
+    }
+
+    DebugInfoOffset { direct_offset, indirect_offsets, result: place }
+}
+
 impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     pub fn set_debug_loc(&self, bx: &mut Bx, source_info: mir::SourceInfo) {
         bx.set_span(source_info.span);
@@ -262,33 +362,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             let Some(dbg_var) = var.dbg_var else { continue };
             let Some(dbg_loc) = self.dbg_loc(var.source_info) else { continue };
 
-            let mut direct_offset = Size::ZERO;
-            // FIXME(eddyb) use smallvec here.
-            let mut indirect_offsets = vec![];
-            let mut place = base;
-
-            for elem in &var.projection[..] {
-                match *elem {
-                    mir::ProjectionElem::Deref => {
-                        indirect_offsets.push(Size::ZERO);
-                        place = bx.load_operand(place).deref(bx.cx());
-                    }
-                    mir::ProjectionElem::Field(field, _) => {
-                        let i = field.index();
-                        let offset = indirect_offsets.last_mut().unwrap_or(&mut direct_offset);
-                        *offset += place.layout.fields.offset(i);
-                        place = place.project_field(bx, i);
-                    }
-                    mir::ProjectionElem::Downcast(_, variant) => {
-                        place = place.project_downcast(bx, variant);
-                    }
-                    _ => span_bug!(
-                        var.source_info.span,
-                        "unsupported var debuginfo place `{:?}`",
-                        mir::Place { local, projection: var.projection },
-                    ),
-                }
-            }
+            let DebugInfoOffset { direct_offset, indirect_offsets, result: _ } =
+                calculate_debuginfo_offset(bx, local, &var, base.layout);
 
             // When targeting MSVC, create extra allocas for arguments instead of pointing multiple
             // dbg_var_addr() calls into the same alloca with offsets. MSVC uses CodeView records
@@ -306,6 +381,9 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     || !matches!(&indirect_offsets[..], [Size::ZERO] | []));
 
             if should_create_individual_allocas {
+                let DebugInfoOffset { direct_offset: _, indirect_offsets: _, result: place } =
+                    calculate_debuginfo_offset(bx, local, &var, base);
+
                 // Create a variable which will be a pointer to the actual value
                 let ptr_ty = bx.tcx().mk_ty(ty::RawPtr(ty::TypeAndMut {
                     mutbl: mir::Mutability::Mut,

compiler/rustc_const_eval/src/interpret/terminator.rs

@@ -29,10 +29,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
             Goto { target } => self.go_to_block(target),
 
-            SwitchInt { ref discr, ref targets, switch_ty } => {
+            SwitchInt { ref discr, ref targets } => {
                 let discr = self.read_immediate(&self.eval_operand(discr, None)?)?;
                 trace!("SwitchInt({:?})", *discr);
-                assert_eq!(discr.layout.ty, switch_ty);
 
                 // Branch to the `otherwise` case by default, if no match is found.
                 let mut target_block = targets.otherwise();

compiler/rustc_const_eval/src/transform/validate.rs

@@ -686,17 +686,8 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             TerminatorKind::Goto { target } => {
                 self.check_edge(location, *target, EdgeKind::Normal);
             }
-            TerminatorKind::SwitchInt { targets, switch_ty, discr } => {
-                let ty = discr.ty(&self.body.local_decls, self.tcx);
-                if ty != *switch_ty {
-                    self.fail(
-                        location,
-                        format!(
-                            "encountered `SwitchInt` terminator with type mismatch: {:?} != {:?}",
-                            ty, switch_ty,
-                        ),
-                    );
-                }
+            TerminatorKind::SwitchInt { targets, discr } => {
+                let switch_ty = discr.ty(&self.body.local_decls, self.tcx);
 
                 let target_width = self.tcx.sess.target.pointer_width;