Use Builder::std where possible

Author: Kobzol

src/bootstrap/src/core/build_steps/check.rs

@@ -1,6 +1,5 @@
 //! Implementation of compiling the compiler and standard library, in "check"-based modes.
 
-use crate::core::build_steps::compile;
 use crate::core::build_steps::compile::{
     add_to_sysroot, run_cargo, rustc_cargo, rustc_cargo_env, std_cargo, std_crates_for_run_make,
 };
@@ -106,7 +105,7 @@ impl Step for Std {
             }
 
             // Reuse the stage0 libstd
-            builder.ensure(compile::Std::new(compiler, target));
+            builder.std(compiler, target);
             return;
         }
 
@@ -253,8 +252,8 @@ impl Step for Rustc {
             // the sysroot for the compiler to find. Otherwise, we're going to
             // fail when building crates that need to generate code (e.g., build
             // scripts and their dependencies).
-            builder.ensure(crate::core::build_steps::compile::Std::new(compiler, compiler.host));
-            builder.ensure(crate::core::build_steps::compile::Std::new(compiler, target));
+            builder.std(compiler, compiler.host);
+            builder.std(compiler, target);
         } else {
             builder.ensure(Std::new(target).build_kind(self.override_build_kind));
         }

src/bootstrap/src/core/build_steps/clippy.rs

@@ -1,8 +1,8 @@
 //! Implementation of running clippy on the compiler, standard library and various tools.
 
+use super::check;
 use super::compile::{run_cargo, rustc_cargo, std_cargo};
 use super::tool::{SourceType, prepare_tool_cargo};
-use super::{check, compile};
 use crate::builder::{Builder, ShouldRun};
 use crate::core::build_steps::compile::std_crates_for_run_make;
 use crate::core::builder;
@@ -214,8 +214,8 @@ impl Step for Rustc {
                 // the sysroot for the compiler to find. Otherwise, we're going to
                 // fail when building crates that need to generate code (e.g., build
                 // scripts and their dependencies).
-                builder.ensure(compile::Std::new(compiler, compiler.host));
-                builder.ensure(compile::Std::new(compiler, target));
+                builder.std(compiler, compiler.host);
+                builder.std(compiler, target);
             } else {
                 builder.ensure(check::Std::new(target).build_kind(Some(Kind::Check)));
             }

src/bootstrap/src/core/build_steps/compile.rs

@@ -212,7 +212,7 @@ impl Step for Std {
         {
             trace!(?compiler_to_use, ?compiler, "compiler != compiler_to_use, uplifting library");
 
-            builder.ensure(Std::new(compiler_to_use, target));
+            builder.std(compiler_to_use, target);
             let msg = if compiler_to_use.host == target {
                 format!(
                     "Uplifting library (stage{} -> stage{})",
@@ -681,7 +681,7 @@ pub fn std_cargo(builder: &Builder<'_>, target: TargetSelection, stage: u32, car
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
-struct StdLink {
+pub struct StdLink {
     pub compiler: Compiler,
     pub target_compiler: Compiler,
     pub target: TargetSelection,
@@ -692,7 +692,7 @@ struct StdLink {
 }
 
 impl StdLink {
-    fn from_std(std: Std, host_compiler: Compiler) -> Self {
+    pub fn from_std(std: Std, host_compiler: Compiler) -> Self {
         Self {
             compiler: host_compiler,
             target_compiler: std.compiler,
@@ -1058,7 +1058,7 @@ impl Step for Rustc {
 
         // Build a standard library for `target` using the `build_compiler`.
         // This will be the standard library that the rustc which we build *links to*.
-        builder.ensure(Std::new(build_compiler, target));
+        builder.std(build_compiler, target);
 
         if builder.config.keep_stage.contains(&build_compiler.stage) {
             trace!(stage = build_compiler.stage, "`keep-stage` requested");
@@ -1099,10 +1099,10 @@ impl Step for Rustc {
         // build scripts and proc macros.
         // If we are not cross-compiling, the Std build above will be the same one as the one we
         // prepare here.
-        builder.ensure(Std::new(
+        builder.std(
             builder.compiler(self.build_compiler.stage, builder.config.host_target),
             builder.config.host_target,
-        ));
+        );
 
         let mut cargo = builder::Cargo::new(
             builder,
@@ -2062,15 +2062,15 @@ impl Step for Assemble {
         if builder.download_rustc() {
             trace!("`download-rustc` requested, reusing CI compiler for stage > 0");
 
-            builder.ensure(Std::new(target_compiler, target_compiler.host));
+            builder.std(target_compiler, target_compiler.host);
             let sysroot =
                 builder.ensure(Sysroot { compiler: target_compiler, force_recompile: false });
             // Ensure that `libLLVM.so` ends up in the newly created target directory,
             // so that tools using `rustc_private` can use it.
             dist::maybe_install_llvm_target(builder, target_compiler.host, &sysroot);
             // Lower stages use `ci-rustc-sysroot`, not stageN
             if target_compiler.stage == builder.top_stage {
-                builder.info(&format!("Creating a sysroot for stage{stage} compiler (use `rustup toolchain link 'name' build/host/stage{stage}`)", stage=target_compiler.stage));
+                builder.info(&format!("Creating a sysroot for stage{stage} compiler (use `rustup toolchain link 'name' build/host/stage{stage}`)", stage = target_compiler.stage));
             }
 
             let mut precompiled_compiler = target_compiler;

src/bootstrap/src/core/build_steps/dist.rs

@@ -711,7 +711,7 @@ impl Step for Std {
             return None;
         }
 
-        builder.ensure(compile::Std::new(compiler, target));
+        builder.std(compiler, target);
 
         let mut tarball = Tarball::new(builder, "rust-std", &target.triple);
         tarball.include_target_in_component_name(true);

src/bootstrap/src/core/build_steps/doc.rs

@@ -804,7 +804,7 @@ impl Step for Rustc {
         // Build the standard library, so that proc-macros can use it.
         // (Normally, only the metadata would be necessary, but proc-macros are special since they run at compile-time.)
         let compiler = builder.compiler(stage, builder.config.host_target);
-        builder.ensure(compile::Std::new(compiler, builder.config.host_target));
+        builder.std(compiler, builder.config.host_target);
 
         let _guard = builder.msg_sysroot_tool(
             Kind::Doc,
@@ -947,7 +947,7 @@ macro_rules! tool_doc {
                 t!(fs::create_dir_all(&out));
 
                 let compiler = builder.compiler(stage, builder.config.host_target);
-                builder.ensure(compile::Std::new(compiler, target));
+                builder.std(compiler, target);
 
                 if true $(&& $rustc_tool)? {
                     // Build rustc docs so that we generate relative links.
@@ -1195,7 +1195,7 @@ impl Step for RustcBook {
         let rustc = builder.rustc(self.compiler);
         // The tool runs `rustc` for extracting output examples, so it needs a
         // functional sysroot.
-        builder.ensure(compile::Std::new(self.compiler, self.target));
+        builder.std(self.compiler, self.target);
         let mut cmd = builder.tool_cmd(Tool::LintDocs);
         cmd.arg("--src");
         cmd.arg(builder.src.join("compiler"));
@@ -1272,7 +1272,7 @@ impl Step for Reference {
 
         // This is needed for generating links to the standard library using
         // the mdbook-spec plugin.
-        builder.ensure(compile::Std::new(self.compiler, builder.config.host_target));
+        builder.std(self.compiler, builder.config.host_target);
 
         // Run rustbook/mdbook to generate the HTML pages.
         builder.ensure(RustbookSrc {

src/bootstrap/src/core/build_steps/perf.rs

@@ -1,7 +1,7 @@
 use std::env::consts::EXE_EXTENSION;
 use std::fmt::{Display, Formatter};
 
-use crate::core::build_steps::compile::{Std, Sysroot};
+use crate::core::build_steps::compile::Sysroot;
 use crate::core::build_steps::tool::{RustcPerf, Rustdoc};
 use crate::core::builder::Builder;
 use crate::core::config::DebuginfoLevel;
@@ -152,7 +152,7 @@ Consider setting `rust.debuginfo-level = 1` in `bootstrap.toml`."#);
     }
 
     let compiler = builder.compiler(builder.top_stage, builder.config.host_target);
-    builder.ensure(Std::new(compiler, builder.config.host_target));
+    builder.std(compiler, builder.config.host_target);
 
     if let Some(opts) = args.cmd.shared_opts()
         && opts.profiles.contains(&Profile::Doc)

src/bootstrap/src/core/build_steps/test.rs

@@ -10,7 +10,7 @@ use std::{env, fs, iter};
 
 use clap_complete::shells;
 
-use crate::core::build_steps::compile::run_cargo;
+use crate::core::build_steps::compile::{Std, run_cargo};
 use crate::core::build_steps::doc::DocumentationFormat;
 use crate::core::build_steps::gcc::{Gcc, add_cg_gcc_cargo_flags};
 use crate::core::build_steps::llvm::get_llvm_version;
@@ -544,7 +544,7 @@ impl Step for Miri {
         // We also need sysroots, for Miri and for the host (the latter for build scripts).
         // This is for the tests so everything is done with the target compiler.
         let miri_sysroot = Miri::build_miri_sysroot(builder, target_compiler, target);
-        builder.ensure(compile::Std::new(target_compiler, host));
+        builder.std(target_compiler, host);
         let host_sysroot = builder.sysroot(target_compiler);
 
         // Miri has its own "target dir" for ui test dependencies. Make sure it gets cleared when
@@ -709,7 +709,7 @@ impl Step for CompiletestTest {
 
         // We need `ToolStd` for the locally-built sysroot because
         // compiletest uses unstable features of the `test` crate.
-        builder.ensure(compile::Std::new(compiler, host));
+        builder.std(compiler, host);
         let mut cargo = tool::prepare_tool_cargo(
             builder,
             compiler,
@@ -1009,7 +1009,7 @@ impl Step for RustdocGUI {
     }
 
     fn run(self, builder: &Builder<'_>) {
-        builder.ensure(compile::Std::new(self.compiler, self.target));
+        builder.std(self.compiler, self.target);
 
         let mut cmd = builder.tool_cmd(Tool::RustdocGUITest);
 
@@ -1634,15 +1634,15 @@ NOTE: if you're sure you want to do this, please open an issue as to why. In the
         if suite == "mir-opt" {
             builder.ensure(compile::Std::new(compiler, compiler.host).is_for_mir_opt_tests(true));
         } else {
-            builder.ensure(compile::Std::new(compiler, compiler.host));
+            builder.std(compiler, compiler.host);
         }
 
         let mut cmd = builder.tool_cmd(Tool::Compiletest);
 
         if suite == "mir-opt" {
             builder.ensure(compile::Std::new(compiler, target).is_for_mir_opt_tests(true));
         } else {
-            builder.ensure(compile::Std::new(compiler, target));
+            builder.std(compiler, target);
         }
 
         builder.ensure(RemoteCopyLibs { compiler, target });
@@ -2178,7 +2178,7 @@ impl BookTest {
     fn run_ext_doc(self, builder: &Builder<'_>) {
         let compiler = self.compiler;
 
-        builder.ensure(compile::Std::new(compiler, compiler.host));
+        builder.std(compiler, compiler.host);
 
         // mdbook just executes a binary named "rustdoc", so we need to update
         // PATH so that it points to our rustdoc.
@@ -2264,7 +2264,7 @@ impl BookTest {
         let compiler = self.compiler;
         let host = self.compiler.host;
 
-        builder.ensure(compile::Std::new(compiler, host));
+        builder.std(compiler, host);
 
         let _guard =
             builder.msg(Kind::Test, compiler.stage, format!("book {}", self.name), host, host);
@@ -2411,7 +2411,7 @@ impl Step for ErrorIndex {
         drop(guard);
         // The tests themselves need to link to std, so make sure it is
         // available.
-        builder.ensure(compile::Std::new(compiler, compiler.host));
+        builder.std(compiler, compiler.host);
         markdown_test(builder, compiler, &output);
     }
 }
@@ -2474,7 +2474,7 @@ impl Step for CrateLibrustc {
     }
 
     fn run(self, builder: &Builder<'_>) {
-        builder.ensure(compile::Std::new(self.compiler, self.target));
+        builder.std(self.compiler, self.target);
 
         // To actually run the tests, delegate to a copy of the `Crate` step.
         builder.ensure(Crate {
@@ -2642,7 +2642,7 @@ impl Step for Crate {
 
         // Prepare sysroot
         // See [field@compile::Std::force_recompile].
-        builder.ensure(compile::Std::new(compiler, compiler.host).force_recompile(true));
+        builder.ensure(Std::new(compiler, compiler.host).force_recompile(true));
 
         // If we're not doing a full bootstrap but we're testing a stage2
         // version of libstd, then what we're actually testing is the libstd
@@ -2768,7 +2768,7 @@ impl Step for CrateRustdoc {
         // using `download-rustc`, the rustc_private artifacts may be in a *different sysroot* from
         // the target rustdoc (`ci-rustc-sysroot` vs `stage2`). In that case, we need to ensure this
         // explicitly to make sure it ends up in the stage2 sysroot.
-        builder.ensure(compile::Std::new(compiler, target));
+        builder.std(compiler, target);
         builder.ensure(compile::Rustc::new(compiler, target));
 
         let mut cargo = tool::prepare_tool_cargo(
@@ -2912,7 +2912,7 @@ impl Step for RemoteCopyLibs {
             return;
         }
 
-        builder.ensure(compile::Std::new(compiler, target));
+        builder.std(compiler, target);
 
         builder.info(&format!("REMOTE copy libs to emulator ({target})"));
 
@@ -3102,7 +3102,7 @@ impl Step for TierCheck {
 
     /// Tests the Platform Support page in the rustc book.
     fn run(self, builder: &Builder<'_>) {
-        builder.ensure(compile::Std::new(self.compiler, self.compiler.host));
+        builder.std(self.compiler, self.compiler.host);
         let mut cargo = tool::prepare_tool_cargo(
             builder,
             self.compiler,
@@ -3335,7 +3335,7 @@ impl Step for CodegenCranelift {
         let compiler = self.compiler;
         let target = self.target;
 
-        builder.ensure(compile::Std::new(compiler, target));
+        builder.std(compiler, target);
 
         // If we're not doing a full bootstrap but we're testing a stage2
         // version of libstd, then what we're actually testing is the libstd

src/bootstrap/src/core/build_steps/tool.rs

@@ -129,7 +129,7 @@ impl Step for ToolBuild {
             Mode::ToolStd => {
                 // If compiler was forced, its artifacts should be prepared earlier.
                 if !self.compiler.is_forced_compiler() {
-                    builder.ensure(compile::Std::new(self.compiler, target))
+                    builder.std(self.compiler, target)
                 }
             }
             Mode::ToolBootstrap => {} // uses downloaded stage0 compiler libs

src/bootstrap/src/core/builder/cargo.rs

@@ -3,8 +3,8 @@ use std::ffi::{OsStr, OsString};
 use std::path::{Path, PathBuf};
 
 use super::{Builder, Kind};
+use crate::core::build_steps::test;
 use crate::core::build_steps::tool::SourceType;
-use crate::core::build_steps::{compile, test};
 use crate::core::config::SplitDebuginfo;
 use crate::core::config::flags::Color;
 use crate::utils::build_stamp;
@@ -844,7 +844,7 @@ impl Builder<'_> {
 
         // If this is for `miri-test`, prepare the sysroots.
         if cmd_kind == Kind::MiriTest {
-            self.ensure(compile::Std::new(compiler, compiler.host));
+            self.std(compiler, compiler.host);
             let host_sysroot = self.sysroot(compiler);
             let miri_sysroot = test::Miri::build_miri_sysroot(self, compiler, target);
             cargo.env("MIRI_SYSROOT", &miri_sysroot);

src/bootstrap/src/core/builder/mod.rs

@@ -15,6 +15,7 @@ use tracing::instrument;
 
 pub use self::cargo::{Cargo, cargo_profile_var};
 pub use crate::Compiler;
+use crate::core::build_steps::compile::{Std, StdLink};
 use crate::core::build_steps::{
     check, clean, clippy, compile, dist, doc, gcc, install, llvm, run, setup, test, tool, vendor,
 };
@@ -1314,6 +1315,49 @@ impl<'a> Builder<'a> {
         resolved_compiler
     }
 
+    /// Obtain a standard library for the given target that will be built by the passed compiler.
+    /// The standard library will be linked to the sysroot of the passed compiler.
+    ///
+    /// Prefer using this method rather than manually invoking `Std::new`.
+    #[cfg_attr(
+        feature = "tracing",
+        instrument(
+            level = "trace",
+            name = "Builder::std",
+            target = "STD",
+            skip_all,
+            fields(
+                stage = stage,
+                host = ?host,
+            ),
+        ),
+    )]
+    pub fn std(&self, compiler: Compiler, target: TargetSelection) {
+        // FIXME: make the `Std` step return some type-level "proof" that std was indeed built,
+        // and then require passing that to all Cargo invocations that we do.
+
+        // The "stage 0" std is always precompiled and comes with the stage0 compiler, so we have
+        // special logic for it, to avoid creating needless and confusing Std steps that don't
+        // actually build anything.
+        if compiler.stage == 0 {
+            if target != compiler.host {
+                panic!(
+                    r"It is not possible to build the standard library for `{target}` using the stage0 compiler.
+You have to build a stage1 compiler for `{}` first, and then use it to build a standard library for `{target}`.
+",
+                    compiler.host
+                )
+            }
+
+            // We still need to link the prebuilt standard library into the ephemeral stage0 sysroot
+            self.ensure(StdLink::from_std(Std::new(compiler, target), compiler));
+        } else {
+            // This step both compiles the std and links it into the compiler's sysroot.
+            // Yes, it's quite magical and side-effecty.. would be nice to refactor later.
+            self.ensure(Std::new(compiler, target));
+        }
+    }
+
     pub fn sysroot(&self, compiler: Compiler) -> PathBuf {
         self.ensure(compile::Sysroot::new(compiler))
     }