Auto merge of #144934 - samueltardieu:rollup-25jvb9g, r=samueltardieu

Rollup of 17 pull requests

Successful merges:

 - rust-lang/rust#144467 (rustdoc template font links only emit `crossorigin` when needed)
 - rust-lang/rust#144548 (Rehome 21 `tests/ui/issues/` tests to other subdirectories under `tests/ui/`)
 - rust-lang/rust#144741 (fix: Error on illegal `[const]`s inside blocks within legal positions)
 - rust-lang/rust#144776 (`Printer` cleanups)
 - rust-lang/rust#144779 (Implement debugging output of the bootstrap Step graph into a DOT file)
 - rust-lang/rust#144813 (Add a tidy check to prevent adding UI tests directly under `tests/ui/`)
 - rust-lang/rust#144817 (Properly reject tail calls to `&FnPtr` or `&FnDef`)
 - rust-lang/rust#144852 (Rename `rust_panic_without_hook` to `resume_unwind` )
 - rust-lang/rust#144866 (Remove `SHOULD_EMIT_LINTS` in favor of `should_emit`)
 - rust-lang/rust#144867 (Use `as_array` in PartialEq for arrays)
 - rust-lang/rust#144872 (Document Poisoning in `LazyCell` and `LazyLock`)
 - rust-lang/rust#144877 (coverage: Various small cleanups)
 - rust-lang/rust#144887 (`rust-analyzer` subtree update)
 - rust-lang/rust#144890 (Add `InterpCx::project_fields`)
 - rust-lang/rust#144894 (Delete `tests/ui/threads-sendsync/tcp-stress.rs`)
 - rust-lang/rust#144905 (rustc-dev-guide subtree update)
 - rust-lang/rust#144920 (Dont print arg span in MIR dump for tail call)

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

2 files changed, 49 insertions, 27 deletions

diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
index 8c9dfcfd18c..d1cb95507d9 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::sync::Arc;
 
 use itertools::Itertools;
@@ -5,6 +6,7 @@ use rustc_abi::Align;
 use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, ConstCodegenMethods};
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_index::IndexVec;
+use rustc_macros::TryFromU32;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::RemapFileNameExt;
 use rustc_session::config::RemapPathScopeComponents;
@@ -20,6 +22,23 @@ mod covfun;
 mod spans;
 mod unused;
 
+/// Version number that will be included the `__llvm_covmap` section header.
+/// Corresponds to LLVM's `llvm::coverage::CovMapVersion` (in `CoverageMapping.h`),
+/// or at least the subset that we know and care about.
+///
+/// Note that version `n` is encoded as `(n-1)`.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, TryFromU32)]
+enum CovmapVersion {
+    /// Used by LLVM 18 onwards.
+    Version7 = 6,
+}
+
+impl CovmapVersion {
+    fn to_u32(self) -> u32 {
+        self as u32
+    }
+}
+
 /// Generates and exports the coverage map, which is embedded in special
 /// linker sections in the final binary.
 ///
@@ -29,19 +48,13 @@ pub(crate) fn finalize(cx: &mut CodegenCx<'_, '_>) {
     let tcx = cx.tcx;
 
     // Ensure that LLVM is using a version of the coverage mapping format that
-    // agrees with our Rust-side code. Expected versions (encoded as n-1) are:
-    // - `CovMapVersion::Version7` (6) used by LLVM 18-19
-    let covmap_version = {
-        let llvm_covmap_version = llvm_cov::mapping_version();
-        let expected_versions = 6..=6;
-        assert!(
-            expected_versions.contains(&llvm_covmap_version),
-            "Coverage mapping version exposed by `llvm-wrapper` is out of sync; \
-            expected {expected_versions:?} but was {llvm_covmap_version}"
-        );
-        // This is the version number that we will embed in the covmap section:
-        llvm_covmap_version
-    };
+    // agrees with our Rust-side code. Expected versions are:
+    // - `Version7` (6) used by LLVM 18 onwards.
+    let covmap_version =
+        CovmapVersion::try_from(llvm_cov::mapping_version()).unwrap_or_else(|raw_version: u32| {
+            panic!("unknown coverage mapping version reported by `llvm-wrapper`: {raw_version}")
+        });
+    assert_matches!(covmap_version, CovmapVersion::Version7);
 
     debug!("Generating coverage map for CodegenUnit: `{}`", cx.codegen_unit.name());
 
@@ -201,7 +214,11 @@ impl VirtualFileMapping {
 /// Generates the contents of the covmap record for this CGU, which mostly
 /// consists of a header and a list of filenames. The record is then stored
 /// as a global variable in the `__llvm_covmap` section.
-fn generate_covmap_record<'ll>(cx: &mut CodegenCx<'ll, '_>, version: u32, filenames_buffer: &[u8]) {
+fn generate_covmap_record<'ll>(
+    cx: &mut CodegenCx<'ll, '_>,
+    version: CovmapVersion,
+    filenames_buffer: &[u8],
+) {
     // A covmap record consists of four target-endian u32 values, followed by
     // the encoded filenames table. Two of the header fields are unused in
     // modern versions of the LLVM coverage mapping format, and are always 0.
@@ -212,7 +229,7 @@ fn generate_covmap_record<'ll>(cx: &mut CodegenCx<'ll, '_>, version: u32, filena
             cx.const_u32(0), // (unused)
             cx.const_u32(filenames_buffer.len() as u32),
             cx.const_u32(0), // (unused)
-            cx.const_u32(version),
+            cx.const_u32(version.to_u32()),
         ],
         /* packed */ false,
     );
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs
index b704cf2b1cd..fd1e7f7f160 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs
@@ -27,6 +27,9 @@ use crate::llvm;
 /// the final record that will be embedded in the `__llvm_covfun` section.
 #[derive(Debug)]
 pub(crate) struct CovfunRecord<'tcx> {
+    /// Not used directly, but helpful in debug messages.
+    _instance: Instance<'tcx>,
+
     mangled_function_name: &'tcx str,
     source_hash: u64,
     is_used: bool,
@@ -55,6 +58,7 @@ pub(crate) fn prepare_covfun_record<'tcx>(
     let expressions = prepare_expressions(ids_info);
 
     let mut covfun = CovfunRecord {
+        _instance: instance,
         mangled_function_name: tcx.symbol_name(instance).name,
         source_hash: if is_used { fn_cov_info.function_source_hash } else { 0 },
         is_used,
@@ -102,11 +106,21 @@ fn fill_region_tables<'tcx>(
     ids_info: &'tcx CoverageIdsInfo,
     covfun: &mut CovfunRecord<'tcx>,
 ) {
+    // If this function is unused, replace all counters with zero.
+    let counter_for_bcb = |bcb: BasicCoverageBlock| -> ffi::Counter {
+        let term = if covfun.is_used {
+            ids_info.term_for_bcb[bcb].expect("every BCB in a mapping was given a term")
+        } else {
+            CovTerm::Zero
+        };
+        ffi::Counter::from_term(term)
+    };
+
     // Currently a function's mappings must all be in the same file, so use the
     // first mapping's span to determine the file.
     let source_map = tcx.sess.source_map();
     let Some(first_span) = (try { fn_cov_info.mappings.first()?.span }) else {
-        debug_assert!(false, "function has no mappings: {:?}", covfun.mangled_function_name);
+        debug_assert!(false, "function has no mappings: {covfun:?}");
         return;
     };
     let source_file = source_map.lookup_source_file(first_span.lo());
@@ -117,7 +131,7 @@ fn fill_region_tables<'tcx>(
     // codegen needs to handle that gracefully to avoid #133606.
     // It's hard for tests to trigger this organically, so instead we set
     // `-Zcoverage-options=discard-all-spans-in-codegen` to force it to occur.
-    let discard_all = tcx.sess.coverage_discard_all_spans_in_codegen();
+    let discard_all = tcx.sess.coverage_options().discard_all_spans_in_codegen;
     let make_coords = |span: Span| {
         if discard_all { None } else { spans::make_coords(source_map, &source_file, span) }
     };
@@ -133,16 +147,6 @@ fn fill_region_tables<'tcx>(
     // For each counter/region pair in this function+file, convert it to a
     // form suitable for FFI.
     for &Mapping { ref kind, span } in &fn_cov_info.mappings {
-        // If this function is unused, replace all counters with zero.
-        let counter_for_bcb = |bcb: BasicCoverageBlock| -> ffi::Counter {
-            let term = if covfun.is_used {
-                ids_info.term_for_bcb[bcb].expect("every BCB in a mapping was given a term")
-            } else {
-                CovTerm::Zero
-            };
-            ffi::Counter::from_term(term)
-        };
-
         let Some(coords) = make_coords(span) else { continue };
         let cov_span = coords.make_coverage_span(local_file_id);
 
@@ -184,6 +188,7 @@ pub(crate) fn generate_covfun_record<'tcx>(
     covfun: &CovfunRecord<'tcx>,
 ) {
     let &CovfunRecord {
+        _instance,
         mangled_function_name,
         source_hash,
         is_used,