Auto merge of #129442 - tgross35:rollup-gmqng7g, r=tgross35

Rollup of 7 pull requests

Successful merges:

 - #126985 (Implement `-Z embed-source` (DWARFv5 source code embedding extension))
 - #128349 (Enable `f16` tests on x86 and x86-64)
 - #128511 (Document WebAssembly target feature expectations)
 - #129263 (Add a missing compatibility note in the 1.80.0 release notes)
 - #129276 (Stabilize feature `char_indices_offset`)
 - #129350 (adapt integer comparison tests for LLVM 20 IR changes)
 - #129408 (Fix handling of macro arguments within the `dropping_copy_types` lint)

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

Author: bors

RELEASES.md

@@ -143,6 +143,8 @@ Compatibility Notes
 - [Turn `proc_macro_back_compat` lint into a hard error.](https://github.com/rust-lang/rust/pull/125596/)
 - [Detect unused structs even when implementing private traits](https://github.com/rust-lang/rust/pull/122382/)
 - [`std::sync::ReentrantLockGuard<T>` is no longer `Sync` if `T: !Sync`](https://github.com/rust-lang/rust/pull/125527) which means [`std::io::StdoutLock` and `std::io::StderrLock` are no longer Sync](https://github.com/rust-lang/rust/issues/127340)
+- [Type inference will fail in some cases due to new implementations of `FromIterator for Box<str>`.](https://github.com/rust-lang/rust/pull/99969/)
+  Notably, this breaks versions of the `time` crate before 0.3.35, due to no longer inferring the implementation for `Box<[_]>`.
 
 <a id="1.80-Internal-Changes"></a>
 

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -629,6 +629,9 @@ pub fn file_metadata<'ll>(cx: &CodegenCx<'ll, '_>, source_file: &SourceFile) ->
         };
         let hash_value = hex_encode(source_file.src_hash.hash_bytes());
 
+        let source =
+            cx.sess().opts.unstable_opts.embed_source.then_some(()).and(source_file.src.as_ref());
+
         unsafe {
             llvm::LLVMRustDIBuilderCreateFile(
                 DIB(cx),
@@ -639,6 +642,8 @@ pub fn file_metadata<'ll>(cx: &CodegenCx<'ll, '_>, source_file: &SourceFile) ->
                 hash_kind,
                 hash_value.as_ptr().cast(),
                 hash_value.len(),
+                source.map_or(ptr::null(), |x| x.as_ptr().cast()),
+                source.map_or(0, |x| x.len()),
             )
         }
     }
@@ -659,6 +664,8 @@ pub fn unknown_file_metadata<'ll>(cx: &CodegenCx<'ll, '_>) -> &'ll DIFile {
             llvm::ChecksumKind::None,
             hash_value.as_ptr().cast(),
             hash_value.len(),
+            ptr::null(),
+            0,
         )
     })
 }
@@ -943,6 +950,8 @@ pub fn build_compile_unit_di_node<'ll, 'tcx>(
             llvm::ChecksumKind::None,
             ptr::null(),
             0,
+            ptr::null(),
+            0,
         );
 
         let unit_metadata = llvm::LLVMRustDIBuilderCreateCompileUnit(

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -1860,6 +1860,8 @@ extern "C" {
         CSKind: ChecksumKind,
         Checksum: *const c_char,
         ChecksumLen: size_t,
+        Source: *const c_char,
+        SourceLen: size_t,
     ) -> &'a DIFile;
 
     pub fn LLVMRustDIBuilderCreateSubroutineType<'a>(

compiler/rustc_interface/src/tests.rs

@@ -774,6 +774,7 @@ fn test_unstable_options_tracking_hash() {
     tracked!(direct_access_external_data, Some(true));
     tracked!(dual_proc_macros, true);
     tracked!(dwarf_version, Some(5));
+    tracked!(embed_source, true);
     tracked!(emit_thin_lto, false);
     tracked!(export_executable_symbols, true);
     tracked!(fewer_names, Some(true));

compiler/rustc_lint/src/drop_forget_useless.rs

@@ -151,10 +151,11 @@ impl<'tcx> LateLintPass<'tcx> for DropForgetUseless {
                     && let Node::Stmt(stmt) = node
                     && let StmtKind::Semi(e) = stmt.kind
                     && e.hir_id == expr.hir_id
+                    && let Some(arg_span) = arg.span.find_ancestor_inside(expr.span)
                 {
                     UseLetUnderscoreIgnoreSuggestion::Suggestion {
-                        start_span: expr.span.shrink_to_lo().until(arg.span),
-                        end_span: arg.span.shrink_to_hi().until(expr.span.shrink_to_hi()),
+                        start_span: expr.span.shrink_to_lo().until(arg_span),
+                        end_span: arg_span.shrink_to_hi().until(expr.span.shrink_to_hi()),
                     }
                 } else {
                     UseLetUnderscoreIgnoreSuggestion::Note

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -913,14 +913,19 @@ extern "C" LLVMMetadataRef
 LLVMRustDIBuilderCreateFile(LLVMRustDIBuilderRef Builder, const char *Filename,
                             size_t FilenameLen, const char *Directory,
                             size_t DirectoryLen, LLVMRustChecksumKind CSKind,
-                            const char *Checksum, size_t ChecksumLen) {
+                            const char *Checksum, size_t ChecksumLen,
+                            const char *Source, size_t SourceLen) {
 
   std::optional<DIFile::ChecksumKind> llvmCSKind = fromRust(CSKind);
   std::optional<DIFile::ChecksumInfo<StringRef>> CSInfo{};
   if (llvmCSKind)
     CSInfo.emplace(*llvmCSKind, StringRef{Checksum, ChecksumLen});
+  std::optional<StringRef> oSource{};
+  if (Source)
+    oSource = StringRef(Source, SourceLen);
   return wrap(Builder->createFile(StringRef(Filename, FilenameLen),
-                                  StringRef(Directory, DirectoryLen), CSInfo));
+                                  StringRef(Directory, DirectoryLen), CSInfo,
+                                  oSource));
 }
 
 extern "C" LLVMMetadataRef

compiler/rustc_session/messages.ftl

@@ -14,6 +14,10 @@ session_crate_name_empty = crate name must not be empty
 
 session_crate_name_invalid = crate names cannot start with a `-`, but `{$s}` has a leading hyphen
 
+session_embed_source_insufficient_dwarf_version = `-Zembed-source=y` requires at least `-Z dwarf-version=5` but DWARF version is {$dwarf_version}
+
+session_embed_source_requires_debug_info = `-Zembed-source=y` requires debug information to be enabled
+
 session_expr_parentheses_needed = parentheses are required to parse this as an expression
 
 session_failed_to_create_profiler = failed to create profiler: {$err}

compiler/rustc_session/src/errors.rs

@@ -165,6 +165,16 @@ pub(crate) struct UnsupportedDwarfVersion {
     pub(crate) dwarf_version: u32,
 }
 
+#[derive(Diagnostic)]
+#[diag(session_embed_source_insufficient_dwarf_version)]
+pub(crate) struct EmbedSourceInsufficientDwarfVersion {
+    pub(crate) dwarf_version: u32,
+}
+
+#[derive(Diagnostic)]
+#[diag(session_embed_source_requires_debug_info)]
+pub(crate) struct EmbedSourceRequiresDebugInfo;
+
 #[derive(Diagnostic)]
 #[diag(session_target_stack_protector_not_supported)]
 pub(crate) struct StackProtectorNotSupportedForTarget<'a> {

compiler/rustc_session/src/options.rs

@@ -1701,6 +1701,8 @@ options! {
         them only if an error has not been emitted"),
     ehcont_guard: bool = (false, parse_bool, [TRACKED],
         "generate Windows EHCont Guard tables"),
+    embed_source: bool = (false, parse_bool, [TRACKED],
+        "embed source text in DWARF debug sections (default: no)"),
     emit_stack_sizes: bool = (false, parse_bool, [UNTRACKED],
         "emit a section containing stack size metadata (default: no)"),
     emit_thin_lto: bool = (true, parse_bool, [TRACKED],

compiler/rustc_session/src/session.rs

@@ -37,8 +37,9 @@ use rustc_target::spec::{
 use crate::code_stats::CodeStats;
 pub use crate::code_stats::{DataTypeKind, FieldInfo, FieldKind, SizeKind, VariantInfo};
 use crate::config::{
-    self, CoverageLevel, CrateType, ErrorOutputType, FunctionReturn, Input, InstrumentCoverage,
-    OptLevel, OutFileName, OutputType, RemapPathScopeComponents, SwitchWithOptPath,
+    self, CoverageLevel, CrateType, DebugInfo, ErrorOutputType, FunctionReturn, Input,
+    InstrumentCoverage, OptLevel, OutFileName, OutputType, RemapPathScopeComponents,
+    SwitchWithOptPath,
 };
 use crate::parse::{add_feature_diagnostics, ParseSess};
 use crate::search_paths::{PathKind, SearchPath};
@@ -1306,6 +1307,19 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
             .emit_err(errors::SplitDebugInfoUnstablePlatform { debuginfo: sess.split_debuginfo() });
     }
 
+    if sess.opts.unstable_opts.embed_source {
+        let dwarf_version =
+            sess.opts.unstable_opts.dwarf_version.unwrap_or(sess.target.default_dwarf_version);
+
+        if dwarf_version < 5 {
+            sess.dcx().emit_warn(errors::EmbedSourceInsufficientDwarfVersion { dwarf_version });
+        }
+
+        if sess.opts.debuginfo == DebugInfo::None {
+            sess.dcx().emit_warn(errors::EmbedSourceRequiresDebugInfo);
+        }
+    }
+
     if sess.opts.unstable_opts.instrument_xray.is_some() && !sess.target.options.supports_xray {
         sess.dcx().emit_err(errors::InstrumentationNotSupported { us: "XRay".to_string() });
     }

library/core/src/lib.rs

@@ -110,7 +110,6 @@
 #![cfg_attr(bootstrap, feature(offset_of_nested))]
 #![feature(array_ptr_get)]
 #![feature(asm_experimental_arch)]
-#![feature(char_indices_offset)]
 #![feature(const_align_of_val)]
 #![feature(const_align_of_val_raw)]
 #![feature(const_align_offset)]

library/core/src/num/f16.rs

@@ -261,7 +261,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// let nan = f16::NAN;
     /// let f = 7.0_f16;
@@ -293,7 +293,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// let f = 7.0f16;
     /// let inf = f16::INFINITY;
@@ -319,7 +319,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// let f = 7.0f16;
     /// let inf: f16 = f16::INFINITY;
@@ -347,7 +347,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// let min = f16::MIN_POSITIVE; // 6.1035e-5
     /// let max = f16::MAX;
@@ -377,7 +377,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// let min = f16::MIN_POSITIVE; // 6.1035e-5
     /// let max = f16::MAX;
@@ -409,7 +409,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// use std::num::FpCategory;
     ///
@@ -867,7 +867,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// let value = 4.6_f16;
     /// let rounded = unsafe { value.to_int_unchecked::<u16>() };
@@ -910,7 +910,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// # // FIXME(f16_f128): enable this once const casting works
     /// # // assert_ne!((1f16).to_bits(), 1f16 as u128); // to_bits() is not casting!
@@ -958,7 +958,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// let v = f16::from_bits(0x4a40);
     /// assert_eq!(v, 12.5);
@@ -1071,7 +1071,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// let value = f16::from_be_bytes([0x4a, 0x40]);
     /// assert_eq!(value, 12.5);
@@ -1094,7 +1094,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// let value = f16::from_le_bytes([0x40, 0x4a]);
     /// assert_eq!(value, 12.5);
@@ -1124,7 +1124,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// let value = f16::from_ne_bytes(if cfg!(target_endian = "big") {
     ///     [0x4a, 0x40]
@@ -1257,7 +1257,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885
+    /// # #[cfg(target_arch = "x86_64")] {
     ///
     /// assert!((-3.0f16).clamp(-2.0, 1.0) == -2.0);
     /// assert!((0.0f16).clamp(-2.0, 1.0) == 0.0);

library/core/src/str/iter.rs

@@ -241,24 +241,35 @@ impl<'a> CharIndices<'a> {
     /// Returns the byte position of the next character, or the length
     /// of the underlying string if there are no more characters.
     ///
+    /// This means that, when the iterator has not been fully consumed,
+    /// the returned value will match the index that will be returned
+    /// by the next call to [`next()`](Self::next).
+    ///
     /// # Examples
     ///
     /// ```
-    /// #![feature(char_indices_offset)]
     /// let mut chars = "a楽".char_indices();
     ///
+    /// // `next()` has not been called yet, so `offset()` returns the byte
+    /// // index of the first character of the string, which is always 0.
     /// assert_eq!(chars.offset(), 0);
+    /// // As expected, the first call to `next()` also returns 0 as index.
     /// assert_eq!(chars.next(), Some((0, 'a')));
     ///
+    /// // `next()` has been called once, so `offset()` returns the byte index
+    /// // of the second character ...
     /// assert_eq!(chars.offset(), 1);
+    /// // ... which matches the index returned by the next call to `next()`.
     /// assert_eq!(chars.next(), Some((1, '楽')));
     ///
+    /// // Once the iterator has been consumed, `offset()` returns the length
+    /// // in bytes of the string.
     /// assert_eq!(chars.offset(), 4);
     /// assert_eq!(chars.next(), None);
     /// ```
     #[inline]
     #[must_use]
-    #[unstable(feature = "char_indices_offset", issue = "83871")]
+    #[stable(feature = "char_indices_offset", since = "CURRENT_RUSTC_VERSION")]
     pub fn offset(&self) -> usize {
         self.front_offset
     }

library/std/build.rs

@@ -103,9 +103,6 @@ fn main() {
         ("arm64ec", _) => false,
         // MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054>
         ("x86_64", "windows") => false,
-        // x86 has ABI bugs that show up with optimizations. This should be partially fixed with
-        // the compiler-builtins update. <https://github.com/rust-lang/rust/issues/123885>
-        ("x86" | "x86_64", _) => false,
         // Missing `__gnu_h2f_ieee` and `__gnu_f2h_ieee`
         ("powerpc" | "powerpc64", _) => false,
         // Missing `__gnu_h2f_ieee` and `__gnu_f2h_ieee`
@@ -140,17 +137,17 @@ fn main() {
         _ => false,
     };
 
-    // These are currently empty, but will fill up as some platforms move from completely
-    // unreliable to reliable basics but unreliable math.
+    // Configure platforms that have reliable basics but may have unreliable math.
 
     // LLVM is currenlty adding missing routines, <https://github.com/llvm/llvm-project/issues/93566>
     let has_reliable_f16_math = has_reliable_f16
         && match (target_arch.as_str(), target_os.as_str()) {
             // FIXME: Disabled on Miri as the intrinsics are not implemented yet.
             _ if is_miri => false,
-            // Currently nothing special. Hooray!
-            // This will change as platforms gain better better support for standard ops but math
-            // lags behind.
+            // x86 has a crash for `powi`: <https://github.com/llvm/llvm-project/issues/105747>
+            ("x86" | "x86_64", _) => false,
+            // Assume that working `f16` means working `f16` math for most platforms, since
+            // operations just go through `f32`.
             _ => true,
         };
 

src/doc/rustc/src/SUMMARY.md

@@ -81,6 +81,7 @@
     - [wasm32-wasip1](platform-support/wasm32-wasip1.md)
     - [wasm32-wasip1-threads](platform-support/wasm32-wasip1-threads.md)
     - [wasm32-wasip2](platform-support/wasm32-wasip2.md)
+    - [wasm32-unknown-unknown](platform-support/wasm32-unknown-unknown.md)
     - [wasm64-unknown-unknown](platform-support/wasm64-unknown-unknown.md)
     - [\*-win7-windows-msvc](platform-support/win7-windows-msvc.md)
     - [x86_64-fortanix-unknown-sgx](platform-support/x86_64-fortanix-unknown-sgx.md)

src/doc/rustc/src/platform-support.md

@@ -192,7 +192,7 @@ target | std | notes
 [`thumbv8m.main-none-eabi`](platform-support/thumbv8m.main-none-eabi.md) | * | Bare Armv8-M Mainline
 [`thumbv8m.main-none-eabihf`](platform-support/thumbv8m.main-none-eabi.md) | * | Bare Armv8-M Mainline, hardfloat
 `wasm32-unknown-emscripten` | ✓ | WebAssembly via Emscripten
-`wasm32-unknown-unknown` | ✓ | WebAssembly
+[`wasm32-unknown-unknown`](platform-support/wasm32-unknown-unknown.md) | ✓ | WebAssembly
 `wasm32-wasi` | ✓ | WebAssembly with WASI (undergoing a [rename to `wasm32-wasip1`][wasi-rename])
 [`wasm32-wasip1`](platform-support/wasm32-wasip1.md) | ✓ | WebAssembly with WASI
 [`wasm32-wasip1-threads`](platform-support/wasm32-wasip1-threads.md) | ✓ | WebAssembly with WASI Preview 1 and threads