compiler/rustc_codegen_llvm/src/back/write.rs

@@ -765,11 +765,21 @@ pub(crate) unsafe fn codegen(
         drop(handlers);
     }
 
+    // `.dwo` files are only emitted if:
+    //
+    // - Object files are being emitted (i.e. bitcode only or metadata only compilations will not
+    //   produce dwarf objects, even if otherwise enabled)
+    // - Target supports Split DWARF
+    // - Split debuginfo is enabled
+    // - Split DWARF kind is `split` (i.e. debuginfo is split into `.dwo` files, not different
+    //   sections in the `.o` files).
+    let dwarf_object_emitted = matches!(config.emit_obj, EmitObj::ObjectCode(_))
+        && cgcx.target_can_use_split_dwarf
+        && cgcx.split_debuginfo != SplitDebuginfo::Off
+        && cgcx.split_dwarf_kind == SplitDwarfKind::Split;
     Ok(module.into_compiled_module(
         config.emit_obj != EmitObj::None,
-        cgcx.target_can_use_split_dwarf
-            && cgcx.split_debuginfo != SplitDebuginfo::Off
-            && cgcx.split_dwarf_kind == SplitDwarfKind::Split,
+        dwarf_object_emitted,
         config.emit_bc,
         &cgcx.output_filenames,
     ))

src/bootstrap/builder.rs

@@ -1074,11 +1074,11 @@ impl<'a> Builder<'a> {
         let mut hasher = sha2::Sha256::new();
         // FIXME: this is ok for rustfmt (4.1 MB large at time of writing), but it seems memory-intensive for rustc and larger components.
         // Consider using streaming IO instead?
-        let contents = if self.config.dry_run { vec![] } else { t!(fs::read(path)) };
+        let contents = if self.config.dry_run() { vec![] } else { t!(fs::read(path)) };
         hasher.update(&contents);
         let found = hex::encode(hasher.finalize().as_slice());
         let verified = found == expected;
-        if !verified && !self.config.dry_run {
+        if !verified && !self.config.dry_run() {
             println!(
                 "invalid checksum: \n\
                 found:    {found}\n\
@@ -1292,7 +1292,7 @@ impl<'a> Builder<'a> {
     /// Note that this returns `None` if LLVM is disabled, or if we're in a
     /// check build or dry-run, where there's no need to build all of LLVM.
     fn llvm_config(&self, target: TargetSelection) -> Option<PathBuf> {
-        if self.config.llvm_enabled() && self.kind != Kind::Check && !self.config.dry_run {
+        if self.config.llvm_enabled() && self.kind != Kind::Check && !self.config.dry_run() {
             let llvm_config = self.ensure(native::Llvm { target });
             if llvm_config.is_file() {
                 return Some(llvm_config);
@@ -1644,7 +1644,7 @@ impl<'a> Builder<'a> {
         //
         // Only clear out the directory if we're compiling std; otherwise, we
         // should let Cargo take care of things for us (via depdep info)
-        if !self.config.dry_run && mode == Mode::Std && cmd == "build" {
+        if !self.config.dry_run() && mode == Mode::Std && cmd == "build" {
             self.clear_if_dirty(&out_dir, &self.rustc(compiler));
         }
 
@@ -2142,7 +2142,7 @@ impl<'a> Builder<'a> {
             (out, dur - deps)
         };
 
-        if self.config.print_step_timings && !self.config.dry_run {
+        if self.config.print_step_timings && !self.config.dry_run() {
             let step_string = format!("{:?}", step);
             let brace_index = step_string.find("{").unwrap_or(0);
             let type_string = type_name::<S>();
@@ -2216,7 +2216,7 @@ impl<'a> Builder<'a> {
     }
 
     pub(crate) fn open_in_browser(&self, path: impl AsRef<Path>) {
-        if self.config.dry_run || !self.config.cmd.open() {
+        if self.config.dry_run() || !self.config.cmd.open() {
             return;
         }
 

src/bootstrap/builder/tests.rs

@@ -1,5 +1,5 @@
 use super::*;
-use crate::config::{Config, TargetSelection};
+use crate::config::{Config, DryRun, TargetSelection};
 use std::thread;
 
 fn configure(cmd: &str, host: &[&str], target: &[&str]) -> Config {
@@ -10,7 +10,7 @@ fn configure_with_args(cmd: &[String], host: &[&str], target: &[&str]) -> Config
     let mut config = Config::parse(cmd);
     // don't save toolstates
     config.save_toolstates = None;
-    config.dry_run = true;
+    config.dry_run = DryRun::SelfCheck;
 
     // Ignore most submodules, since we don't need them for a dry run.
     // But make sure to check out the `doc` and `rust-analyzer` submodules, since some steps need them

src/bootstrap/compile.rs

@@ -447,7 +447,7 @@ fn copy_sanitizers(
 ) -> Vec<PathBuf> {
     let runtimes: Vec<native::SanitizerRuntime> = builder.ensure(native::Sanitizers { target });
 
-    if builder.config.dry_run {
+    if builder.config.dry_run() {
         return Vec::new();
     }
 
@@ -986,7 +986,7 @@ impl Step for CodegenBackend {
             compiler.stage, backend, &compiler.host, target
         ));
         let files = run_cargo(builder, cargo, vec![], &tmp_stamp, vec![], false);
-        if builder.config.dry_run {
+        if builder.config.dry_run() {
             return;
         }
         let mut files = files.into_iter().filter(|f| {
@@ -1034,7 +1034,7 @@ fn copy_codegen_backends_to_sysroot(
     let dst = builder.sysroot_codegen_backends(target_compiler);
     t!(fs::create_dir_all(&dst), dst);
 
-    if builder.config.dry_run {
+    if builder.config.dry_run() {
         return;
     }
 
@@ -1332,7 +1332,7 @@ impl Step for Assemble {
 
         if builder.config.rust_codegen_backends.contains(&INTERNER.intern_str("llvm")) {
             let llvm_config_bin = builder.ensure(native::Llvm { target: target_compiler.host });
-            if !builder.config.dry_run {
+            if !builder.config.dry_run() {
                 let llvm_bin_dir = output(Command::new(llvm_config_bin).arg("--bindir"));
                 let llvm_bin_dir = Path::new(llvm_bin_dir.trim());
 
@@ -1402,7 +1402,7 @@ pub fn run_cargo(
     additional_target_deps: Vec<(PathBuf, DependencyType)>,
     is_check: bool,
 ) -> Vec<PathBuf> {
-    if builder.config.dry_run {
+    if builder.config.dry_run() {
         return Vec::new();
     }
 
@@ -1542,7 +1542,7 @@ pub fn stream_cargo(
     cb: &mut dyn FnMut(CargoMessage<'_>),
 ) -> bool {
     let mut cargo = Command::from(cargo);
-    if builder.config.dry_run {
+    if builder.config.dry_run() {
         return true;
     }
     // Instruct Cargo to give us json messages on stdout, critically leaving

src/bootstrap/config.rs

@@ -33,6 +33,17 @@ macro_rules! check_ci_llvm {
     };
 }
 
+#[derive(Clone, Default)]
+pub enum DryRun {
+    /// This isn't a dry run.
+    #[default]
+    Disabled,
+    /// This is a dry run enabled by bootstrap itself, so it can verify that no work is done.
+    SelfCheck,
+    /// This is a dry run enabled by the `--dry-run` flag.
+    UserSelected,
+}
+
 /// Global configuration for the entire build and/or bootstrap.
 ///
 /// This structure is derived from a combination of both `config.toml` and
@@ -84,7 +95,7 @@ pub struct Config {
     pub jobs: Option<u32>,
     pub cmd: Subcommand,
     pub incremental: bool,
-    pub dry_run: bool,
+    pub dry_run: DryRun,
     /// `None` if we shouldn't download CI compiler artifacts, or the commit to download if we should.
     #[cfg(not(test))]
     download_rustc_commit: Option<String>,
@@ -820,7 +831,7 @@ impl Config {
         config.jobs = flags.jobs.map(threads_from_config);
         config.cmd = flags.cmd;
         config.incremental = flags.incremental;
-        config.dry_run = flags.dry_run;
+        config.dry_run = if flags.dry_run { DryRun::UserSelected } else { DryRun::Disabled };
         config.keep_stage = flags.keep_stage;
         config.keep_stage_std = flags.keep_stage_std;
         config.color = flags.color;
@@ -965,7 +976,7 @@ impl Config {
             .unwrap_or_else(|| config.out.join(config.build.triple).join("stage0/bin/cargo"));
 
         // NOTE: it's important this comes *after* we set `initial_rustc` just above.
-        if config.dry_run {
+        if config.dry_run() {
             let dir = config.out.join("tmp-dry-run");
             t!(fs::create_dir_all(&dir));
             config.out = dir;
@@ -1372,6 +1383,13 @@ impl Config {
         config
     }
 
+    pub(crate) fn dry_run(&self) -> bool {
+        match self.dry_run {
+            DryRun::Disabled => false,
+            DryRun::SelfCheck | DryRun::UserSelected => true,
+        }
+    }
+
     /// A git invocation which runs inside the source directory.
     ///
     /// Use this rather than `Command::new("git")` in order to support out-of-tree builds.
@@ -1461,7 +1479,7 @@ impl Config {
     /// This is computed on demand since LLVM might have to first be downloaded from CI.
     pub(crate) fn llvm_link_shared(builder: &Builder<'_>) -> bool {
         let mut opt = builder.config.llvm_link_shared.get();
-        if opt.is_none() && builder.config.dry_run {
+        if opt.is_none() && builder.config.dry_run() {
             // just assume static for now - dynamic linking isn't supported on all platforms
             return false;
         }
@@ -1488,7 +1506,7 @@ impl Config {
     /// Return whether we will use a downloaded, pre-compiled version of rustc, or just build from source.
     pub(crate) fn download_rustc(builder: &Builder<'_>) -> bool {
         static DOWNLOAD_RUSTC: OnceCell<bool> = OnceCell::new();
-        if builder.config.dry_run && DOWNLOAD_RUSTC.get().is_none() {
+        if builder.config.dry_run() && DOWNLOAD_RUSTC.get().is_none() {
             // avoid trying to actually download the commit
             return false;
         }
@@ -1507,7 +1525,7 @@ impl Config {
             RustfmtState::SystemToolchain(p) | RustfmtState::Downloaded(p) => Some(p.clone()),
             RustfmtState::Unavailable => None,
             r @ RustfmtState::LazyEvaluated => {
-                if builder.config.dry_run {
+                if builder.config.dry_run() {
                     return Some(PathBuf::new());
                 }
                 let path = maybe_download_rustfmt(builder);

src/bootstrap/dist.rs

@@ -945,7 +945,7 @@ impl Step for PlainSourceTarball {
                 .arg(builder.src.join("./src/bootstrap/Cargo.toml"))
                 .current_dir(&plain_dst_src);
 
-            let config = if !builder.config.dry_run {
+            let config = if !builder.config.dry_run() {
                 t!(String::from_utf8(t!(cmd.output()).stdout))
             } else {
                 String::new()
@@ -1153,7 +1153,6 @@ impl Step for Clippy {
 
         let mut tarball = Tarball::new(builder, "clippy", &target.triple);
         tarball.set_overlay(OverlayKind::Clippy);
-        tarball.is_preview(true);
         tarball.add_file(clippy, "bin", 0o755);
         tarball.add_file(cargoclippy, "bin", 0o755);
         tarball.add_legal_and_readme_to("share/doc/clippy");
@@ -1251,7 +1250,6 @@ impl Step for Rustfmt {
             .expect("cargo fmt expected to build - essential tool");
         let mut tarball = Tarball::new(builder, "rustfmt", &target.triple);
         tarball.set_overlay(OverlayKind::Rustfmt);
-        tarball.is_preview(true);
         tarball.add_file(rustfmt, "bin", 0o755);
         tarball.add_file(cargofmt, "bin", 0o755);
         tarball.add_legal_and_readme_to("share/doc/rustfmt");
@@ -1386,7 +1384,7 @@ impl Step for Extended {
         let etc = builder.src.join("src/etc/installer");
 
         // Avoid producing tarballs during a dry run.
-        if builder.config.dry_run {
+        if builder.config.dry_run() {
             return;
         }
 
@@ -1818,7 +1816,7 @@ impl Step for Extended {
             let _time = timeit(builder);
             builder.run(&mut cmd);
 
-            if !builder.config.dry_run {
+            if !builder.config.dry_run() {
                 t!(fs::rename(exe.join(&filename), distdir(builder).join(&filename)));
             }
         }
@@ -1882,12 +1880,12 @@ fn maybe_install_llvm(builder: &Builder<'_>, target: TargetSelection, dst_libdir
         if llvm_dylib_path.exists() {
             builder.install(&llvm_dylib_path, dst_libdir, 0o644);
         }
-        !builder.config.dry_run
+        !builder.config.dry_run()
     } else if let Ok(llvm_config) = crate::native::prebuilt_llvm_config(builder, target) {
         let mut cmd = Command::new(llvm_config);
         cmd.arg("--libfiles");
         builder.verbose(&format!("running {:?}", cmd));
-        let files = if builder.config.dry_run { "".into() } else { output(&mut cmd) };
+        let files = if builder.config.dry_run() { "".into() } else { output(&mut cmd) };
         let build_llvm_out = &builder.llvm_out(builder.config.build);
         let target_llvm_out = &builder.llvm_out(target);
         for file in files.trim_end().split(' ') {
@@ -1899,7 +1897,7 @@ fn maybe_install_llvm(builder: &Builder<'_>, target: TargetSelection, dst_libdir
             };
             builder.install(&file, dst_libdir, 0o644);
         }
-        !builder.config.dry_run
+        !builder.config.dry_run()
     } else {
         false
     }

src/bootstrap/doc.rs

@@ -151,7 +151,7 @@ impl Step for RustbookSrc {
         let index = out.join("index.html");
         let rustbook = builder.tool_exe(Tool::Rustbook);
         let mut rustbook_cmd = builder.tool_cmd(Tool::Rustbook);
-        if builder.config.dry_run || up_to_date(&src, &index) && up_to_date(&rustbook, &index) {
+        if builder.config.dry_run() || up_to_date(&src, &index) && up_to_date(&rustbook, &index) {
             return;
         }
         builder.info(&format!("Rustbook ({}) - {}", target, name));
@@ -331,8 +331,8 @@ impl Step for Standalone {
                 && up_to_date(&footer, &html)
                 && up_to_date(&favicon, &html)
                 && up_to_date(&full_toc, &html)
-                && (builder.config.dry_run || up_to_date(&version_info, &html))
-                && (builder.config.dry_run || up_to_date(&rustdoc, &html))
+                && (builder.config.dry_run() || up_to_date(&version_info, &html))
+                && (builder.config.dry_run() || up_to_date(&rustdoc, &html))
             {
                 continue;
             }
@@ -402,7 +402,7 @@ impl Step for SharedAssets {
 
         let version_input = builder.src.join("src").join("doc").join("version_info.html.template");
         let version_info = out.join("version_info.html");
-        if !builder.config.dry_run && !up_to_date(&version_input, &version_info) {
+        if !builder.config.dry_run() && !up_to_date(&version_input, &version_info) {
             let info = t!(fs::read_to_string(&version_input))
                 .replace("VERSION", &builder.rust_release())
                 .replace("SHORT_HASH", builder.rust_info.sha_short().unwrap_or(""))
@@ -900,7 +900,7 @@ impl Step for UnstableBookGen {
 }
 
 fn symlink_dir_force(config: &Config, src: &Path, dst: &Path) -> io::Result<()> {
-    if config.dry_run {
+    if config.dry_run() {
         return Ok(());
     }
     if let Ok(m) = fs::symlink_metadata(dst) {

src/bootstrap/format.rs

@@ -43,7 +43,7 @@ struct RustfmtConfig {
 }
 
 pub fn format(build: &Builder<'_>, check: bool, paths: &[PathBuf]) {
-    if build.config.dry_run {
+    if build.config.dry_run() {
         return;
     }
     let mut builder = ignore::types::TypesBuilder::new();