Rework standard library building

Author: bjorn3

build_sysroot/Cargo.lock

@@ -1,18 +1,10 @@
-[package]
-name = "sysroot"
-version = "0.0.0"
-
-[dependencies]
-core = { path = "./sysroot_src/library/core" }
-alloc = { path = "./sysroot_src/library/alloc" }
-std = { path = "./sysroot_src/library/std", features = ["panic_unwind", "backtrace"] }
-test = { path = "./sysroot_src/library/test" }
-proc_macro = { path = "./sysroot_src/library/proc_macro" }
+[workspace]
+members = ["./library/sysroot"]
 
 [patch.crates-io]
-rustc-std-workspace-core = { path = "./sysroot_src/library/rustc-std-workspace-core" }
-rustc-std-workspace-alloc = { path = "./sysroot_src/library/rustc-std-workspace-alloc" }
-rustc-std-workspace-std = { path = "./sysroot_src/library/rustc-std-workspace-std" }
+rustc-std-workspace-core = { path = "./library/rustc-std-workspace-core" }
+rustc-std-workspace-alloc = { path = "./library/rustc-std-workspace-alloc" }
+rustc-std-workspace-std = { path = "./library/rustc-std-workspace-std" }
 
 [profile.dev]
 lto = "off"

build_sysroot/Cargo.toml

@@ -156,11 +156,10 @@ impl SysrootTarget {
 }
 
 pub(crate) static ORIG_BUILD_SYSROOT: RelPath = RelPath::SOURCE.join("build_sysroot");
-pub(crate) static BUILD_SYSROOT: RelPath = RelPath::BUILD.join("sysroot");
-pub(crate) static SYSROOT_RUSTC_VERSION: RelPath = BUILD_SYSROOT.join("rustc_version");
-pub(crate) static SYSROOT_SRC: RelPath = BUILD_SYSROOT.join("sysroot_src");
+pub(crate) static STDLIB_SRC: RelPath = RelPath::BUILD.join("stdlib");
+pub(crate) static SYSROOT_RUSTC_VERSION: RelPath = STDLIB_SRC.join("rustc_version");
 pub(crate) static STANDARD_LIBRARY: CargoProject =
-    CargoProject::new(&BUILD_SYSROOT, "build_sysroot");
+    CargoProject::new(&STDLIB_SRC.join("library/sysroot"), "stdlib_target");
 pub(crate) static RTSTARTUP_SYSROOT: RelPath = RelPath::BUILD.join("rtstartup");
 
 #[must_use]
@@ -277,7 +276,7 @@ fn build_clif_sysroot_for_triple(
     if channel == "release" {
         build_cmd.arg("--release");
     }
-    build_cmd.arg("--features").arg("std/compiler-builtins-no-asm");
+    build_cmd.arg("--features").arg("compiler-builtins-no-asm backtrace panic-unwind");
     build_cmd.arg("--locked");
     build_cmd.env("__CARGO_DEFAULT_LIB_METADATA", "cg_clif");
     if compiler.triple.contains("apple") {
@@ -307,7 +306,7 @@ fn build_rtstartup(dirs: &Dirs, compiler: &Compiler) -> Option<SysrootTarget> {
 
     RTSTARTUP_SYSROOT.ensure_fresh(dirs);
 
-    let rtstartup_src = SYSROOT_SRC.to_path(dirs).join("library").join("rtstartup");
+    let rtstartup_src = STDLIB_SRC.to_path(dirs).join("library").join("rtstartup");
     let mut target_libs = SysrootTarget { triple: compiler.triple.clone(), libs: vec![] };
 
     for file in ["rsbegin", "rsend"] {

build_sysroot/src/lib.rs

@@ -3,7 +3,7 @@ use std::fs;
 use std::path::{Path, PathBuf};
 use std::process::Command;
 
-use super::build_sysroot::{BUILD_SYSROOT, ORIG_BUILD_SYSROOT, SYSROOT_RUSTC_VERSION, SYSROOT_SRC};
+use super::build_sysroot::{ORIG_BUILD_SYSROOT, STDLIB_SRC, SYSROOT_RUSTC_VERSION};
 use super::path::{Dirs, RelPath};
 use super::rustc_info::{get_default_sysroot, get_rustc_version};
 use super::utils::{
@@ -28,15 +28,10 @@ fn prepare_stdlib(dirs: &Dirs, rustc: &Path) {
     let sysroot_src_orig = get_default_sysroot(rustc).join("lib/rustlib/src/rust");
     assert!(sysroot_src_orig.exists());
 
-    eprintln!("[COPY] stdlib src");
+    apply_patches(dirs, "stdlib", &sysroot_src_orig, &STDLIB_SRC.to_path(dirs));
 
     // FIXME ensure builds error out or update the copy if any of the files copied here change
-    BUILD_SYSROOT.ensure_fresh(dirs);
-    copy_dir_recursively(&ORIG_BUILD_SYSROOT.to_path(dirs), &BUILD_SYSROOT.to_path(dirs));
-
-    fs::create_dir_all(SYSROOT_SRC.to_path(dirs).join("library")).unwrap();
-
-    apply_patches(dirs, "stdlib", &sysroot_src_orig, &SYSROOT_SRC.to_path(dirs));
+    copy_dir_recursively(&ORIG_BUILD_SYSROOT.to_path(dirs), &STDLIB_SRC.to_path(dirs));
 
     let rustc_version = get_rustc_version(rustc);
     fs::write(SYSROOT_RUSTC_VERSION.to_path(dirs), &rustc_version).unwrap();
@@ -251,6 +246,8 @@ fn get_patches(dirs: &Dirs, crate_name: &str) -> Vec<PathBuf> {
 pub(crate) fn apply_patches(dirs: &Dirs, crate_name: &str, source_dir: &Path, target_dir: &Path) {
     // FIXME avoid copy and patch if src, patches and target are unchanged
 
+    eprintln!("[COPY] {crate_name} source");
+
     remove_dir_if_exists(target_dir);
     fs::create_dir_all(target_dir).unwrap();
     copy_dir_recursively(source_dir, target_dir);