Auto merge of rust-lang#139508 - Zalathar:rollup-ldbvvyf, r=compiler-errors

Rollup of 19 pull requests

Successful merges:

 - rust-lang#138676 (Implement overflow for infinite implied lifetime bounds)
 - rust-lang#139024 (Make error message for missing fields with `..` and without `..` more consistent)
 - rust-lang#139098 (Tell LLVM about impossible niche tags)
 - rust-lang#139124 (compiler: report error when trait object type param reference self)
 - rust-lang#139321 (Update to new rinja version (askama))
 - rust-lang#139346 (Don't construct preds w escaping bound vars in `diagnostic_hir_wf_check`)
 - rust-lang#139386 (make it possible to use stage0 libtest on compiletest)
 - rust-lang#139421 (Fix trait upcasting to dyn type with no principal when there are projections)
 - rust-lang#139468 (Don't call `Span::with_parent` on the good path in `has_stashed_diagnostic`)
 - rust-lang#139476 (rm `RegionInferenceContext::var_infos`)
 - rust-lang#139481 (Add job summary links to post-merge report)
 - rust-lang#139485 (compiletest: Stricter parsing for diagnostic kinds)
 - rust-lang#139490 (Update some comment/docs related to "extern intrinsic" removal)
 - rust-lang#139491 (Update books)
 - rust-lang#139496 (Revert r-a changes of rust-lang#139455)
 - rust-lang#139500 (document panic behavior of Vec::resize and Vec::resize_with)
 - rust-lang#139501 (Fix stack overflow in exhaustiveness due to recursive HIR opaque hidden types)
 - rust-lang#139504 (add missing word in doc comment)
 - rust-lang#139507 (compiletest: Trim whitespace from environment variable names)

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

Author: bors

Cargo.lock

@@ -186,6 +186,48 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
 
+[[package]]
+name = "askama"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a4e46abb203e00ef226442d452769233142bbfdd79c3941e84c8e61c4112543"
+dependencies = [
+ "askama_derive",
+ "itoa",
+ "percent-encoding",
+ "serde",
+ "serde_json",
+]
+
+[[package]]
+name = "askama_derive"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54398906821fd32c728135f7b351f0c7494ab95ae421d41b6f5a020e158f28a6"
+dependencies = [
+ "askama_parser",
+ "basic-toml",
+ "memchr",
+ "proc-macro2",
+ "quote",
+ "rustc-hash 2.1.1",
+ "serde",
+ "serde_derive",
+ "syn 2.0.100",
+]
+
+[[package]]
+name = "askama_parser"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf315ce6524c857bb129ff794935cf6d42c82a6cff60526fe2a63593de4d0d4f"
+dependencies = [
+ "memchr",
+ "serde",
+ "serde_derive",
+ "winnow 0.7.4",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.4.0"
@@ -1345,8 +1387,8 @@ name = "generate-copyright"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "askama",
  "cargo_metadata 0.18.1",
- "rinja",
  "serde",
  "serde_json",
  "thiserror 1.0.69",
@@ -3069,9 +3111,7 @@ version = "0.3.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3dc4940d00595430b3d7d5a01f6222b5e5b51395d1120bdb28d854bb8abb17a5"
 dependencies = [
- "humansize",
  "itoa",
- "percent-encoding",
  "rinja_derive",
 ]
 
@@ -4628,6 +4668,7 @@ name = "rustdoc"
 version = "0.0.0"
 dependencies = [
  "arrayvec",
+ "askama",
  "base64",
  "expect-test",
  "indexmap",
@@ -4636,7 +4677,6 @@ dependencies = [
  "pulldown-cmark 0.9.6",
  "pulldown-cmark-escape",
  "regex",
- "rinja",
  "rustdoc-json-types",
  "serde",
  "serde_json",
@@ -5426,7 +5466,7 @@ dependencies = [
  "serde",
  "serde_spanned",
  "toml_datetime",
- "winnow",
+ "winnow 0.5.40",
 ]
 
 [[package]]
@@ -6437,6 +6477,15 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "winnow"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0e97b544156e9bebe1a0ffbc03484fc1ffe3100cbce3ffb17eac35f7cdd7ab36"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "winsplit"
 version = "0.1.0"

bootstrap.example.toml

@@ -28,7 +28,7 @@
 #  - A new option
 #  - A change in the default values
 #
-# If the change-id does not match the version currently in use, x.py will 
+# If the change-id does not match the version currently in use, x.py will
 # display the changes made to the bootstrap.
 # To suppress these warnings, you can set change-id = "ignore".
 #change-id = <latest change id in src/bootstrap/src/utils/change_tracker.rs>
@@ -442,6 +442,9 @@
 # What custom diff tool to use for displaying compiletest tests.
 #compiletest-diff-tool = <none>
 
+# Whether to use the precompiled stage0 libtest with compiletest.
+#compiletest-use-stage0-libtest = true
+
 # Indicates whether ccache is used when building certain artifacts (e.g. LLVM).
 # Set to `true` to use the first `ccache` in PATH, or set an absolute path to use
 # a specific version.

compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs

@@ -406,8 +406,8 @@ impl<'tcx> TypeOpInfo<'tcx> for crate::type_check::InstantiateOpaqueType<'tcx> {
             // started MIR borrowchecking with, so the region
             // constraints have already been taken. Use the data from
             // our `mbcx` instead.
-            |vid| mbcx.regioncx.var_infos[vid].origin,
-            |vid| mbcx.regioncx.var_infos[vid].universe,
+            |vid| RegionVariableOrigin::Nll(mbcx.regioncx.definitions[vid].origin),
+            |vid| mbcx.regioncx.definitions[vid].universe,
         )
     }
 }

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -8,9 +8,7 @@ use rustc_errors::{Applicability, Diag, EmissionGuarantee, MultiSpan, listify};
 use rustc_hir::def::{CtorKind, Namespace};
 use rustc_hir::{self as hir, CoroutineKind, LangItem};
 use rustc_index::IndexSlice;
-use rustc_infer::infer::{
-    BoundRegionConversionTime, NllRegionVariableOrigin, RegionVariableOrigin,
-};
+use rustc_infer::infer::{BoundRegionConversionTime, NllRegionVariableOrigin};
 use rustc_infer::traits::SelectionError;
 use rustc_middle::bug;
 use rustc_middle::mir::{
@@ -633,9 +631,8 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
     ) {
         let predicate_span = path.iter().find_map(|constraint| {
             let outlived = constraint.sub;
-            if let Some(origin) = self.regioncx.var_infos.get(outlived)
-                && let RegionVariableOrigin::Nll(NllRegionVariableOrigin::Placeholder(_)) =
-                    origin.origin
+            if let Some(origin) = self.regioncx.definitions.get(outlived)
+                && let NllRegionVariableOrigin::Placeholder(_) = origin.origin
                 && let ConstraintCategory::Predicate(span) = constraint.category
             {
                 Some(span)

compiler/rustc_borrowck/src/polonius/dump.rs

@@ -334,7 +334,7 @@ fn emit_mermaid_nll_regions<'tcx>(
     writeln!(out, "flowchart TD")?;
 
     // Emit the region nodes.
-    for region in regioncx.var_infos.indices() {
+    for region in regioncx.definitions.indices() {
         write!(out, "{}[\"", region.as_usize())?;
         render_region(region, regioncx, out)?;
         writeln!(out, "\"]")?;
@@ -387,7 +387,7 @@ fn emit_mermaid_nll_sccs<'tcx>(
     // Gather and emit the SCC nodes.
     let mut nodes_per_scc: IndexVec<_, _> =
         regioncx.constraint_sccs().all_sccs().map(|_| Vec::new()).collect();
-    for region in regioncx.var_infos.indices() {
+    for region in regioncx.definitions.indices() {
         let scc = regioncx.constraint_sccs().scc(region);
         nodes_per_scc[scc].push(region);
     }

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -139,13 +139,11 @@ impl RegionTracker {
 }
 
 pub struct RegionInferenceContext<'tcx> {
-    pub var_infos: VarInfos,
-
     /// Contains the definition for every region variable. Region
     /// variables are identified by their index (`RegionVid`). The
     /// definition contains information about where the region came
     /// from as well as its final inferred value.
-    definitions: IndexVec<RegionVid, RegionDefinition<'tcx>>,
+    pub(crate) definitions: IndexVec<RegionVid, RegionDefinition<'tcx>>,
 
     /// The liveness constraints added to each region. For most
     /// regions, these start out empty and steadily grow, though for
@@ -453,7 +451,6 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             Rc::new(member_constraints.into_mapped(|r| constraint_sccs.scc(r)));
 
         let mut result = Self {
-            var_infos,
             definitions,
             liveness_constraints,
             constraints,

compiler/rustc_codegen_ssa/src/mir/operand.rs

@@ -9,6 +9,7 @@ use rustc_middle::mir::{self, ConstValue};
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
 use rustc_middle::{bug, span_bug};
+use rustc_session::config::OptLevel;
 use tracing::{debug, instrument};
 
 use super::place::{PlaceRef, PlaceValue};
@@ -496,6 +497,18 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
                     _ => (tag_imm, bx.cx().immediate_backend_type(tag_op.layout)),
                 };
 
+                // Layout ensures that we only get here for cases where the discriminant
+                // value and the variant index match, since that's all `Niche` can encode.
+                // But for emphasis and debugging, let's double-check one anyway.
+                debug_assert_eq!(
+                    self.layout
+                        .ty
+                        .discriminant_for_variant(bx.tcx(), untagged_variant)
+                        .unwrap()
+                        .val,
+                    u128::from(untagged_variant.as_u32()),
+                );
+
                 let relative_max = niche_variants.end().as_u32() - niche_variants.start().as_u32();
 
                 // We have a subrange `niche_start..=niche_end` inside `range`.
@@ -537,6 +550,21 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
                         relative_discr,
                         bx.cx().const_uint(tag_llty, relative_max as u64),
                     );
+
+                    // Thanks to parameter attributes and load metadata, LLVM already knows
+                    // the general valid range of the tag. It's possible, though, for there
+                    // to be an impossible value *in the middle*, which those ranges don't
+                    // communicate, so it's worth an `assume` to let the optimizer know.
+                    if niche_variants.contains(&untagged_variant)
+                        && bx.cx().sess().opts.optimize != OptLevel::No
+                    {
+                        let impossible =
+                            u64::from(untagged_variant.as_u32() - niche_variants.start().as_u32());
+                        let impossible = bx.cx().const_uint(tag_llty, impossible);
+                        let ne = bx.icmp(IntPredicate::IntNE, relative_discr, impossible);
+                        bx.assume(ne);
+                    }
+
                     (is_niche, cast_tag, niche_variants.start().as_u32() as u128)
                 };
 
@@ -553,7 +581,9 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
                 );
 
                 // In principle we could insert assumes on the possible range of `discr`, but
-                // currently in LLVM this seems to be a pessimization.
+                // currently in LLVM this isn't worth it because the original `tag` will
+                // have either a `range` parameter attribute or `!range` metadata,
+                // or come from a `transmute` that already `assume`d it.
 
                 discr
             }