diff --git a/RELEASES.md b/RELEASES.md index 2c91ddf782674..5e4827be4ecfd 100644 --- a/RELEASES.md +++ b/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` 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`.](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<[_]>`. diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs index 30f90bada9adc..554a6d26ad901 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs +++ b/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( diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs index faabbcb020d5f..7a495174ff1aa 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs +++ b/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>( diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs index 34f2dca7c42ff..486136a2bcc10 100644 --- a/compiler/rustc_interface/src/tests.rs +++ b/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)); diff --git a/compiler/rustc_lint/src/drop_forget_useless.rs b/compiler/rustc_lint/src/drop_forget_useless.rs index 2060858cc8af0..a9de258e005c9 100644 --- a/compiler/rustc_lint/src/drop_forget_useless.rs +++ b/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 diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp index 79a68b2ff0e67..ed12318c88dae 100644 --- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp +++ b/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 llvmCSKind = fromRust(CSKind); std::optional> CSInfo{}; if (llvmCSKind) CSInfo.emplace(*llvmCSKind, StringRef{Checksum, ChecksumLen}); + std::optional 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 diff --git a/compiler/rustc_session/messages.ftl b/compiler/rustc_session/messages.ftl index b84280a3ccf3f..01c371ee49884 100644 --- a/compiler/rustc_session/messages.ftl +++ b/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} diff --git a/compiler/rustc_session/src/errors.rs b/compiler/rustc_session/src/errors.rs index 5cc54a5855bbe..15bbd4ff7bf4b 100644 --- a/compiler/rustc_session/src/errors.rs +++ b/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> { diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index df72e2430fd50..23231fbffbfdb 100644 --- a/compiler/rustc_session/src/options.rs +++ b/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], diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs index 693867c3853da..68efd0faea5c1 100644 --- a/compiler/rustc_session/src/session.rs +++ b/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() }); } diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs index e3640627c562a..bbfe412fbcf1b 100644 --- a/library/core/src/lib.rs +++ b/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)] diff --git a/library/core/src/num/f16.rs b/library/core/src/num/f16.rs index 41bd34a270238..c00bebadaadd0 100644 --- a/library/core/src/num/f16.rs +++ b/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::() }; @@ -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); diff --git a/library/core/src/str/iter.rs b/library/core/src/str/iter.rs index 06f796f9f3ad8..681ec79c0b7bf 100644 --- a/library/core/src/str/iter.rs +++ b/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 } diff --git a/library/std/build.rs b/library/std/build.rs index 35a5977b6ebaf..26b8669d382d9 100644 --- a/library/std/build.rs +++ b/library/std/build.rs @@ -103,9 +103,6 @@ fn main() { ("arm64ec", _) => false, // MinGW ABI bugs ("x86_64", "windows") => false, - // x86 has ABI bugs that show up with optimizations. This should be partially fixed with - // the compiler-builtins update. - ("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, 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`: + ("x86" | "x86_64", _) => false, + // Assume that working `f16` means working `f16` math for most platforms, since + // operations just go through `f32`. _ => true, }; diff --git a/src/doc/rustc/src/SUMMARY.md b/src/doc/rustc/src/SUMMARY.md index cb0b2e63452de..4e34e2667cfc0 100644 --- a/src/doc/rustc/src/SUMMARY.md +++ b/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) diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md index 667758a120305..dd478e9df379e 100644 --- a/src/doc/rustc/src/platform-support.md +++ b/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 diff --git a/src/doc/rustc/src/platform-support/wasm32-unknown-unknown.md b/src/doc/rustc/src/platform-support/wasm32-unknown-unknown.md new file mode 100644 index 0000000000000..ee37e5e90cfb4 --- /dev/null +++ b/src/doc/rustc/src/platform-support/wasm32-unknown-unknown.md @@ -0,0 +1,198 @@ +# `wasm32-unknown-unknown` + +**Tier: 2** + +The `wasm32-unknown-unknown` target is a WebAssembly compilation target which +does not import any functions from the host for the standard library. This is +the "minimal" WebAssembly in the sense of making the fewest assumptions about +the host environment. This target is often used when compiling to the web or +JavaScript environments as there is no standard for what functions can be +imported on the web. This target can also be useful for creating minimal or +bare-bones WebAssembly binaries. + +The `wasm32-unknown-unknown` target has support for the Rust standard library +but many parts of the standard library do not work and return errors. For +example `println!` does nothing, `std::fs` always return errors, and +`std::thread::spawn` will panic. There is no means by which this can be +overridden. For a WebAssembly target that more fully supports the standard +library see the [`wasm32-wasip1`](./wasm32-wasip1.md) or +[`wasm32-wasip2`](./wasm32-wasip2.md) targets. + +The `wasm32-unknown-unknown` target has full support for the `core` and `alloc` +crates. It additionally supports the `HashMap` type in the `std` crate, although +hash maps are not randomized like they are on other platforms. + +One existing user of this target (please feel free to edit and expand this list +too) is the [`wasm-bindgen` project](https://github.com/rustwasm/wasm-bindgen) +which facilitates Rust code interoperating with JavaScript code. Note, though, +that not all uses of `wasm32-unknown-unknown` are using JavaScript and the web. + +## Target maintainers + +When this target was added to the compiler platform-specific documentation here +was not maintained at that time. This means that the list below is not +exhaustive and there are more interested parties in this target. That being +said since when this document was last updated those interested in maintaining +this target are: + +- Alex Crichton, https://github.com/alexcrichton + +## Requirements + +This target is cross-compiled. The target includes support for `std` itself, +but as mentioned above many pieces of functionality that require an operating +system do not work and will return errors. + +This target currently has no equivalent in C/C++. There is no C/C++ toolchain +for this target. While interop is theoretically possible it's recommended to +instead use one of: + +* `wasm32-unknown-emscripten` - for web-based use cases the Emscripten + toolchain is typically chosen for running C/C++. +* [`wasm32-wasip1`](./wasm32-wasip1.md) - the wasi-sdk toolchain is used to + compile C/C++ on this target and can interop with Rust code. WASI works on + the web so far as there's no blocker, but an implementation of WASI APIs + must be either chosen or reimplemented. + +This target has no build requirements beyond what's in-tree in the Rust +repository. Linking binaries requires LLD to be enabled for the `wasm-ld` +driver. This target uses the `dlmalloc` crate as the default global allocator. + +## Building the target + +Building this target can be done by: + +* Configure the `wasm32-unknown-unknown` target to get built. +* Configure LLD to be built. +* Ensure the `WebAssembly` target backend is not disabled in LLVM. + +These are all controlled through `config.toml` options. It should be possible +to build this target on any platform. + +## Building Rust programs + +Rust programs can be compiled by adding this target via rustup: + +```sh +$ rustup target add wasm32-unknown-unknown +``` + +and then compiling with the target: + +```sh +$ rustc foo.rs --target wasm32-unknown-unknown +$ file foo.wasm +``` + +## Cross-compilation + +This target can be cross-compiled from any host. + +## Testing + +This target is not tested in CI for the rust-lang/rust repository. Many tests +must be disabled to run on this target and failures are non-obvious because +`println!` doesn't work in the standard library. It's recommended to test the +`wasm32-wasip1` target instead for WebAssembly compatibility. + +## Conditionally compiling code + +It's recommended to conditionally compile code for this target with: + +```text +#[cfg(all(target_family = "wasm", target_os = "unknown"))] +``` + +Note that there is no way to tell via `#[cfg]` whether code will be running on +the web or not. + +## Enabled WebAssembly features + +WebAssembly is an evolving standard which adds new features such as new +instructions over time. This target's default set of supported WebAssembly +features will additionally change over time. The `wasm32-unknown-unknown` target +inherits the default settings of LLVM which typically matches the default +settings of Emscripten as well. + +Changes to WebAssembly go through a [proposals process][proposals] but reaching +the final stage (stage 5) does not automatically mean that the feature will be +enabled in LLVM and Rust by default. At this time the general guidance is that +features must be present in most engines for a "good chunk of time" before +they're enabled in LLVM by default. There is currently no exact number of +months or engines that are required to enable features by default. + +[proposals]: https://github.com/WebAssembly/proposals + +As of the time of this writing the proposals that are enabled by default (the +`generic` CPU in LLVM terminology) are: + +* `multivalue` +* `mutable-globals` +* `reference-types` +* `sign-ext` + +If you're compiling WebAssembly code for an engine that does not support a +feature in LLVM's default feature set then the feature must be disabled at +compile time. Note, though, that enabled features may be used in the standard +library or precompiled libraries shipped via rustup. This means that not only +does your own code need to be compiled with the correct set of flags but the +Rust standard library additionally must be recompiled. + +Compiling all code for the initial release of WebAssembly looks like: + +```sh +$ export RUSTFLAGS=-Ctarget-cpu=mvp +$ cargo +nightly build -Zbuild-std=panic_abort,std --target wasm32-unknown-unknown +``` + +Here the `mvp` "cpu" is a placeholder in LLVM for disabling all supported +features by default. Cargo's `-Zbuild-std` feature, a Nightly Rust feature, is +then used to recompile the standard library in addition to your own code. This +will produce a binary that uses only the original WebAssembly features by +default and no proposals since its inception. + +To enable individual features it can be done with `-Ctarget-feature=+foo`. +Available features for Rust code itself are documented in the [reference] and +can also be found through: + +```sh +$ rustc -Ctarget-feature=help --target wasm32-unknown-unknown +``` + +You'll need to consult your WebAssembly engine's documentation to learn more +about the supported WebAssembly features the engine has. + +[reference]: https://doc.rust-lang.org/reference/attributes/codegen.html#wasm32-or-wasm64 + +Note that it is still possible for Rust crates and libraries to enable +WebAssembly features on a per-function level. This means that the build +command above may not be sufficient to disable all WebAssembly features. If the +final binary still has SIMD instructions, for example, the function in question +will need to be found and the crate in question will likely contain something +like: + +```rust,ignore (not-always-compiled-to-wasm) +#[target_feature(enable = "simd128")] +fn foo() { + // ... +} +``` + +In this situation there is no compiler flag to disable emission of SIMD +instructions and the crate must instead be modified to not include this function +at compile time either by default or through a Cargo feature. For crate authors +it's recommended to avoid `#[target_feature(enable = "...")]` except where +necessary and instead use: + +```rust,ignore (not-always-compiled-to-wasm) +#[cfg(target_feature = "simd128")] +fn foo() { + // ... +} +``` + +That is to say instead of enabling target features it's recommended to +conditionally compile code instead. This is notably different to the way native +platforms such as x86\_64 work, and this is due to the fact that WebAssembly +binaries must only contain code the engine understands. Native binaries work so +long as the CPU doesn't execute unknown code dynamically at runtime. diff --git a/src/doc/rustc/src/platform-support/wasm32-wasip1-threads.md b/src/doc/rustc/src/platform-support/wasm32-wasip1-threads.md index c3eda26ca8ef9..994c0f4bbb3e9 100644 --- a/src/doc/rustc/src/platform-support/wasm32-wasip1-threads.md +++ b/src/doc/rustc/src/platform-support/wasm32-wasip1-threads.md @@ -162,3 +162,17 @@ It's recommended to conditionally compile code for this target with: Prior to Rust 1.80 the `target_env = "p1"` key was not set. Currently the `target_feature = "atomics"` is Nightly-only. Note that the precise `#[cfg]` necessary to detect this target may change as the target becomes more stable. + +## Enabled WebAssembly features + +The default set of WebAssembly features enabled for compilation includes two +more features in addition to that which +[`wasm32-unknown-unknown`](./wasm32-unknown-unknown.md) enables: + +* `bulk-memory` +* `atomics` + +For more information about features see the documentation for +[`wasm32-unknown-unknown`](./wasm32-unknown-unknown.md), but note that the +`mvp` CPU in LLVM does not support this target as it's required that +`bulk-memory`, `atomics`, and `mutable-globals` are all enabled. diff --git a/src/doc/rustc/src/platform-support/wasm32-wasip1.md b/src/doc/rustc/src/platform-support/wasm32-wasip1.md index fb70bbdc2b403..0e4def6768dc4 100644 --- a/src/doc/rustc/src/platform-support/wasm32-wasip1.md +++ b/src/doc/rustc/src/platform-support/wasm32-wasip1.md @@ -132,3 +132,9 @@ It's recommended to conditionally compile code for this target with: Note that the `target_env = "p1"` condition first appeared in Rust 1.80. Prior to Rust 1.80 the `target_env` condition was not set. + +## Enabled WebAssembly features + +The default set of WebAssembly features enabled for compilation is currently the +same as [`wasm32-unknown-unknown`](./wasm32-unknown-unknown.md). See the +documentation there for more information. diff --git a/src/doc/rustc/src/platform-support/wasm32-wasip2.md b/src/doc/rustc/src/platform-support/wasm32-wasip2.md index 1e53fbc178e2e..bb2348b201e39 100644 --- a/src/doc/rustc/src/platform-support/wasm32-wasip2.md +++ b/src/doc/rustc/src/platform-support/wasm32-wasip2.md @@ -61,3 +61,9 @@ It's recommended to conditionally compile code for this target with: ```text #[cfg(all(target_os = "wasi", target_env = "p2"))] ``` + +## Enabled WebAssembly features + +The default set of WebAssembly features enabled for compilation is currently the +same as [`wasm32-unknown-unknown`](./wasm32-unknown-unknown.md). See the +documentation there for more information. diff --git a/src/doc/unstable-book/src/compiler-flags/embed-source.md b/src/doc/unstable-book/src/compiler-flags/embed-source.md new file mode 100644 index 0000000000000..01a11e3779712 --- /dev/null +++ b/src/doc/unstable-book/src/compiler-flags/embed-source.md @@ -0,0 +1,12 @@ +# `embed-source` + +This flag controls whether the compiler embeds the program source code text into +the object debug information section. It takes one of the following values: + +* `y`, `yes`, `on` or `true`: put source code in debug info. +* `n`, `no`, `off`, `false` or no value: omit source code from debug info (the default). + +This flag is ignored in configurations that don't emit DWARF debug information +and is ignored on non-LLVM backends. `-Z embed-source` requires DWARFv5. Use +`-Z dwarf-version=5` to control the compiler's DWARF target version and `-g` to +enable debug info generation. diff --git a/tests/assembly/x86_64-cmp.rs b/tests/assembly/x86_64-cmp.rs index 31efdda1bfafa..67b7ff99ae2d9 100644 --- a/tests/assembly/x86_64-cmp.rs +++ b/tests/assembly/x86_64-cmp.rs @@ -1,6 +1,9 @@ -//@ revisions: DEBUG OPTIM +//@ revisions: DEBUG LLVM-PRE-20-OPTIM LLVM-20-OPTIM //@ [DEBUG] compile-flags: -C opt-level=0 -//@ [OPTIM] compile-flags: -C opt-level=3 +//@ [LLVM-PRE-20-OPTIM] compile-flags: -C opt-level=3 +//@ [LLVM-PRE-20-OPTIM] ignore-llvm-version: 20 - 99 +//@ [LLVM-20-OPTIM] compile-flags: -C opt-level=3 +//@ [LLVM-20-OPTIM] min-llvm-version: 20 //@ assembly-output: emit-asm //@ compile-flags: --crate-type=lib -C llvm-args=-x86-asm-syntax=intel //@ only-x86_64 @@ -21,12 +24,18 @@ pub fn signed_cmp(a: i16, b: i16) -> std::cmp::Ordering { // DEBUG: and // DEBUG: sub - // OPTIM: xor - // OPTIM: cmp - // OPTIM: setne - // OPTIM: mov - // OPTIM: cmovge - // OPTIM: ret + // LLVM-PRE-20-OPTIM: xor + // LLVM-PRE-20-OPTIM: cmp + // LLVM-PRE-20-OPTIM: setne + // LLVM-PRE-20-OPTIM: mov + // LLVM-PRE-20-OPTIM: cmovge + // LLVM-PRE-20-OPTIM: ret + // + // LLVM-20-OPTIM: cmp + // LLVM-20-OPTIM: setl + // LLVM-20-OPTIM: setg + // LLVM-20-OPTIM: sub + // LLVM-20-OPTIM: ret three_way_compare(a, b) } @@ -41,11 +50,16 @@ pub fn unsigned_cmp(a: u16, b: u16) -> std::cmp::Ordering { // DEBUG: and // DEBUG: sub - // OPTIM: xor - // OPTIM: cmp - // OPTIM: setne - // OPTIM: mov - // OPTIM: cmovae - // OPTIM: ret + // LLVM-PRE-20-OPTIM: xor + // LLVM-PRE-20-OPTIM: cmp + // LLVM-PRE-20-OPTIM: setne + // LLVM-PRE-20-OPTIM: mov + // LLVM-PRE-20-OPTIM: cmovae + // LLVM-PRE-20-OPTIM: ret + // + // LLVM-20-OPTIM: cmp + // LLVM-20-OPTIM: seta + // LLVM-20-OPTIM: sbb + // LLVM-20-OPTIM: ret three_way_compare(a, b) } diff --git a/tests/codegen/integer-cmp.rs b/tests/codegen/integer-cmp.rs index bba112b246f3f..8df68d8d4906e 100644 --- a/tests/codegen/integer-cmp.rs +++ b/tests/codegen/integer-cmp.rs @@ -1,6 +1,9 @@ // This is test for more optimal Ord implementation for integers. // See for more info. +//@ revisions: llvm-pre-20 llvm-20 +//@ [llvm-20] min-llvm-version: 20 +//@ [llvm-pre-20] ignore-llvm-version: 20 - 99 //@ compile-flags: -C opt-level=3 #![crate_type = "lib"] @@ -10,19 +13,21 @@ use std::cmp::Ordering; // CHECK-LABEL: @cmp_signed #[no_mangle] pub fn cmp_signed(a: i64, b: i64) -> Ordering { - // CHECK: icmp slt - // CHECK: icmp ne - // CHECK: zext i1 - // CHECK: select i1 + // llvm-20: @llvm.scmp.i8.i64 + // llvm-pre-20: icmp slt + // llvm-pre-20: icmp ne + // llvm-pre-20: zext i1 + // llvm-pre-20: select i1 a.cmp(&b) } // CHECK-LABEL: @cmp_unsigned #[no_mangle] pub fn cmp_unsigned(a: u32, b: u32) -> Ordering { - // CHECK: icmp ult - // CHECK: icmp ne - // CHECK: zext i1 - // CHECK: select i1 + // llvm-20: @llvm.ucmp.i8.i32 + // llvm-pre-20: icmp ult + // llvm-pre-20: icmp ne + // llvm-pre-20: zext i1 + // llvm-pre-20: select i1 a.cmp(&b) } diff --git a/tests/run-make/embed-source-dwarf/main.rs b/tests/run-make/embed-source-dwarf/main.rs new file mode 100644 index 0000000000000..c80af84f41415 --- /dev/null +++ b/tests/run-make/embed-source-dwarf/main.rs @@ -0,0 +1,2 @@ +// hello +fn main() {} diff --git a/tests/run-make/embed-source-dwarf/rmake.rs b/tests/run-make/embed-source-dwarf/rmake.rs new file mode 100644 index 0000000000000..06d550121b0de --- /dev/null +++ b/tests/run-make/embed-source-dwarf/rmake.rs @@ -0,0 +1,70 @@ +//@ ignore-windows +//@ ignore-apple + +// LLVM 17's embed-source implementation requires that source code is attached +// for all files in the output DWARF debug info. This restriction was lifted in +// LLVM 18 (87e22bdd2bd6d77d782f9d64b3e3ae5bdcd5080d). +//@ min-llvm-version: 18 + +// This test should be replaced with one in tests/debuginfo once we can easily +// tell via GDB or LLDB if debuginfo contains source code. Cheap tricks in LLDB +// like setting an invalid source map path don't appear to work, maybe this'll +// become easier once GDB supports DWARFv6? + +use std::collections::HashMap; +use std::path::PathBuf; +use std::rc::Rc; + +use gimli::{AttributeValue, EndianRcSlice, Reader, RunTimeEndian}; +use object::{Object, ObjectSection}; +use run_make_support::{gimli, object, rfs, rustc}; + +fn main() { + let output = PathBuf::from("embed-source-main"); + rustc() + .input("main.rs") + .output(&output) + .arg("-g") + .arg("-Zembed-source=yes") + .arg("-Zdwarf-version=5") + .run(); + let output = rfs::read(output); + let obj = object::File::parse(output.as_slice()).unwrap(); + let endian = if obj.is_little_endian() { RunTimeEndian::Little } else { RunTimeEndian::Big }; + let dwarf = gimli::Dwarf::load(|section| -> Result<_, ()> { + let data = obj.section_by_name(section.name()).map(|s| s.uncompressed_data().unwrap()); + Ok(EndianRcSlice::new(Rc::from(data.unwrap_or_default().as_ref()), endian)) + }) + .unwrap(); + + let mut sources = HashMap::new(); + + let mut iter = dwarf.units(); + while let Some(header) = iter.next().unwrap() { + let unit = dwarf.unit(header).unwrap(); + let unit = unit.unit_ref(&dwarf); + + if let Some(program) = &unit.line_program { + let header = program.header(); + for file in header.file_names() { + if let Some(source) = file.source() { + let path = unit + .attr_string(file.path_name()) + .unwrap() + .to_string_lossy() + .unwrap() + .to_string(); + let source = + unit.attr_string(source).unwrap().to_string_lossy().unwrap().to_string(); + if !source.is_empty() { + sources.insert(path, source); + } + } + } + } + } + + dbg!(&sources); + assert_eq!(sources.len(), 1); + assert_eq!(sources.get("main.rs").unwrap(), "// hello\nfn main() {}\n"); +} diff --git a/tests/ui/lint/dropping_copy_types-macros.fixed b/tests/ui/lint/dropping_copy_types-macros.fixed new file mode 100644 index 0000000000000..a8ceedadc8063 --- /dev/null +++ b/tests/ui/lint/dropping_copy_types-macros.fixed @@ -0,0 +1,12 @@ +//@ check-fail +//@ run-rustfix + +#![deny(dropping_copy_types)] + +use std::fmt::Write; + +fn main() { + let mut msg = String::new(); + let _ = writeln!(&mut msg, "test"); + //~^ ERROR calls to `std::mem::drop` +} diff --git a/tests/ui/lint/dropping_copy_types-macros.rs b/tests/ui/lint/dropping_copy_types-macros.rs new file mode 100644 index 0000000000000..b249b0c868f37 --- /dev/null +++ b/tests/ui/lint/dropping_copy_types-macros.rs @@ -0,0 +1,12 @@ +//@ check-fail +//@ run-rustfix + +#![deny(dropping_copy_types)] + +use std::fmt::Write; + +fn main() { + let mut msg = String::new(); + drop(writeln!(&mut msg, "test")); + //~^ ERROR calls to `std::mem::drop` +} diff --git a/tests/ui/lint/dropping_copy_types-macros.stderr b/tests/ui/lint/dropping_copy_types-macros.stderr new file mode 100644 index 0000000000000..117e9f4fe099c --- /dev/null +++ b/tests/ui/lint/dropping_copy_types-macros.stderr @@ -0,0 +1,21 @@ +error: calls to `std::mem::drop` with a value that implements `Copy` does nothing + --> $DIR/dropping_copy_types-macros.rs:10:5 + | +LL | drop(writeln!(&mut msg, "test")); + | ^^^^^--------------------------^ + | | + | argument has type `Result<(), std::fmt::Error>` + | +note: the lint level is defined here + --> $DIR/dropping_copy_types-macros.rs:4:9 + | +LL | #![deny(dropping_copy_types)] + | ^^^^^^^^^^^^^^^^^^^ +help: use `let _ = ...` to ignore the expression or result + | +LL - drop(writeln!(&mut msg, "test")); +LL + let _ = writeln!(&mut msg, "test"); + | + +error: aborting due to 1 previous error +