1 //! Compilation of native dependencies like LLVM.
3 //! Native projects like LLVM unfortunately aren't suited just yet for
4 //! compilation in build scripts that Cargo has. This is because the
5 //! compilation takes a *very* long time but also because we don't want to
6 //! compile LLVM 3 times as part of a normal bootstrap (we want it cached).
8 //! LLVM and compiler-rt are essentially just wired up to everything else to
9 //! ensure that they're always in place if needed.
12 use std::env::consts::EXE_EXTENSION;
13 use std::ffi::{OsStr, OsString};
14 use std::fs::{self, File};
16 use std::path::{Path, PathBuf};
17 use std::process::Command;
19 use crate::builder::{Builder, RunConfig, ShouldRun, Step};
20 use crate::config::TargetSelection;
21 use crate::util::get_clang_cl_resource_dir;
22 use crate::util::{self, exe, output, program_out_of_date, t, up_to_date};
23 use crate::{CLang, GitRepo};
27 build_llvm_config: PathBuf,
32 // Linker flags to pass to LLVM's CMake invocation.
33 #[derive(Debug, Clone, Default)]
35 // CMAKE_EXE_LINKER_FLAGS
37 // CMAKE_SHARED_LINKER_FLAGS
39 // CMAKE_MODULE_LINKER_FLAGS
44 fn push_all(&mut self, s: impl AsRef<OsStr>) {
48 self.shared.push(" ");
50 self.module.push(" ");
55 // This returns whether we've already previously built LLVM.
57 // It's used to avoid busting caches during x.py check -- if we've already built
58 // LLVM, it's fine for us to not try to avoid doing so.
60 // This will return the llvm-config if it can get it (but it will not build it
62 pub fn prebuilt_llvm_config(
63 builder: &Builder<'_>,
64 target: TargetSelection,
65 ) -> Result<PathBuf, Meta> {
66 maybe_download_ci_llvm(builder);
68 // If we're using a custom LLVM bail out here, but we can only use a
69 // custom LLVM for the build triple.
70 if let Some(config) = builder.config.target_config.get(&target) {
71 if let Some(ref s) = config.llvm_config {
72 check_llvm_version(builder, s);
73 return Ok(s.to_path_buf());
77 let root = "src/llvm-project/llvm";
78 let out_dir = builder.llvm_out(target);
80 let mut llvm_config_ret_dir = builder.llvm_out(builder.config.build);
81 if !builder.config.build.contains("msvc") || builder.ninja() {
82 llvm_config_ret_dir.push("build");
84 llvm_config_ret_dir.push("bin");
86 let build_llvm_config = llvm_config_ret_dir.join(exe("llvm-config", builder.config.build));
88 let stamp = out_dir.join("llvm-finished-building");
89 let stamp = HashStamp::new(stamp, builder.in_tree_llvm_info.sha());
91 if builder.config.llvm_skip_rebuild && stamp.path.exists() {
94 Using a potentially stale build of LLVM; \
95 This may not behave well.",
97 return Ok(build_llvm_config);
101 if stamp.hash.is_none() {
103 "Could not determine the LLVM submodule commit hash. \
104 Assuming that an LLVM rebuild is not necessary.",
106 builder.info(&format!(
107 "To force LLVM to rebuild, remove the file `{}`",
111 return Ok(build_llvm_config);
114 Err(Meta { stamp, build_llvm_config, out_dir, root: root.into() })
117 pub(crate) fn maybe_download_ci_llvm(builder: &Builder<'_>) {
118 let config = &builder.config;
119 if !config.llvm_from_ci {
122 let mut rev_list = config.git();
124 PathBuf::from("rev-list"),
125 format!("--author={}", builder.config.stage0_metadata.config.git_merge_commit_email).into(),
127 "--first-parent".into(),
130 builder.src.join("src/llvm-project"),
131 builder.src.join("src/bootstrap/download-ci-llvm-stamp"),
132 // the LLVM shared object file is named `LLVM-12-rust-{version}-nightly`
133 builder.src.join("src/version"),
135 let llvm_sha = output(&mut rev_list);
136 let llvm_sha = llvm_sha.trim();
139 eprintln!("error: could not find commit hash for downloading LLVM");
140 eprintln!("help: maybe your repository history is too shallow?");
141 eprintln!("help: consider disabling `download-ci-llvm`");
142 eprintln!("help: or fetch enough history to include one upstream commit");
146 let llvm_root = config.ci_llvm_root();
147 let llvm_stamp = llvm_root.join(".llvm-stamp");
148 let key = format!("{}{}", llvm_sha, config.llvm_assertions);
149 if program_out_of_date(&llvm_stamp, &key) && !config.dry_run {
150 download_ci_llvm(builder, &llvm_sha);
151 for entry in t!(fs::read_dir(llvm_root.join("bin"))) {
152 builder.fix_bin_or_dylib(&t!(entry).path());
155 // Update the timestamp of llvm-config to force rustc_llvm to be
156 // rebuilt. This is a hacky workaround for a deficiency in Cargo where
157 // the rerun-if-changed directive doesn't handle changes very well.
158 // https://github.com/rust-lang/cargo/issues/10791
159 // Cargo only compares the timestamp of the file relative to the last
160 // time `rustc_llvm` build script ran. However, the timestamps of the
161 // files in the tarball are in the past, so it doesn't trigger a
163 let now = filetime::FileTime::from_system_time(std::time::SystemTime::now());
164 let llvm_config = llvm_root.join("bin").join(exe("llvm-config", builder.config.build));
165 t!(filetime::set_file_times(&llvm_config, now, now));
167 let llvm_lib = llvm_root.join("lib");
168 for entry in t!(fs::read_dir(&llvm_lib)) {
169 let lib = t!(entry).path();
170 if lib.extension().map_or(false, |ext| ext == "so") {
171 builder.fix_bin_or_dylib(&lib);
174 t!(fs::write(llvm_stamp, key));
178 fn download_ci_llvm(builder: &Builder<'_>, llvm_sha: &str) {
179 let llvm_assertions = builder.config.llvm_assertions;
181 let cache_prefix = format!("llvm-{}-{}", llvm_sha, llvm_assertions);
182 let cache_dst = builder.out.join("cache");
183 let rustc_cache = cache_dst.join(cache_prefix);
184 if !rustc_cache.exists() {
185 t!(fs::create_dir_all(&rustc_cache));
187 let base = if llvm_assertions {
188 &builder.config.stage0_metadata.config.artifacts_with_llvm_assertions_server
190 &builder.config.stage0_metadata.config.artifacts_server
192 let channel = builder.config.artifact_channel(llvm_sha);
193 let filename = format!("rust-dev-{}-{}.tar.xz", channel, builder.build.build.triple);
194 let tarball = rustc_cache.join(&filename);
195 if !tarball.exists() {
196 let help_on_error = "error: failed to download llvm from ci
198 help: old builds get deleted after a certain time
199 help: if trying to compile an old commit of rustc, disable `download-ci-llvm` in config.toml:
202 download-ci-llvm = false
204 builder.download_component(
205 &format!("{base}/{llvm_sha}/{filename}"),
210 let llvm_root = builder.config.ci_llvm_root();
211 builder.unpack(&tarball, &llvm_root, "rust-dev");
214 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
216 pub target: TargetSelection,
220 type Output = PathBuf; // path to llvm-config
222 const ONLY_HOSTS: bool = true;
224 fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
225 run.path("src/llvm-project").path("src/llvm-project/llvm")
228 fn make_run(run: RunConfig<'_>) {
229 run.builder.ensure(Llvm { target: run.target });
232 /// Compile LLVM for `target`.
233 fn run(self, builder: &Builder<'_>) -> PathBuf {
234 let target = self.target;
235 let target_native = if self.target.starts_with("riscv") {
236 // RISC-V target triples in Rust is not named the same as C compiler target triples.
237 // This converts Rust RISC-V target triples to C compiler triples.
238 let idx = target.triple.find('-').unwrap();
240 format!("riscv{}{}", &target.triple[5..7], &target.triple[idx..])
241 } else if self.target.starts_with("powerpc") && self.target.ends_with("freebsd") {
242 // FreeBSD 13 had incompatible ABI changes on all PowerPC platforms.
243 // Set the version suffix to 13.0 so the correct target details are used.
244 format!("{}{}", self.target, "13.0")
249 let Meta { stamp, build_llvm_config, out_dir, root } =
250 match prebuilt_llvm_config(builder, target) {
255 builder.update_submodule(&Path::new("src").join("llvm-project"));
256 if builder.llvm_link_shared() && target.contains("windows") {
257 panic!("shared linking to LLVM is not currently supported on {}", target.triple);
260 builder.info(&format!("Building LLVM for {}", target));
262 let _time = util::timeit(&builder);
263 t!(fs::create_dir_all(&out_dir));
265 // https://llvm.org/docs/CMake.html
266 let mut cfg = cmake::Config::new(builder.src.join(root));
267 let mut ldflags = LdFlags::default();
269 let profile = match (builder.config.llvm_optimize, builder.config.llvm_release_debuginfo) {
270 (false, _) => "Debug",
271 (true, false) => "Release",
272 (true, true) => "RelWithDebInfo",
275 // NOTE: remember to also update `config.toml.example` when changing the
277 let llvm_targets = match &builder.config.llvm_targets {
280 "AArch64;ARM;BPF;Hexagon;MSP430;Mips;NVPTX;PowerPC;RISCV;\
281 Sparc;SystemZ;WebAssembly;X86"
285 let llvm_exp_targets = match builder.config.llvm_experimental_targets {
290 let assertions = if builder.config.llvm_assertions { "ON" } else { "OFF" };
291 let plugins = if builder.config.llvm_plugins { "ON" } else { "OFF" };
292 let enable_tests = if builder.config.llvm_tests { "ON" } else { "OFF" };
294 cfg.out_dir(&out_dir)
296 .define("LLVM_ENABLE_ASSERTIONS", assertions)
297 .define("LLVM_ENABLE_PLUGINS", plugins)
298 .define("LLVM_TARGETS_TO_BUILD", llvm_targets)
299 .define("LLVM_EXPERIMENTAL_TARGETS_TO_BUILD", llvm_exp_targets)
300 .define("LLVM_INCLUDE_EXAMPLES", "OFF")
301 .define("LLVM_INCLUDE_DOCS", "OFF")
302 .define("LLVM_INCLUDE_BENCHMARKS", "OFF")
303 .define("LLVM_INCLUDE_TESTS", enable_tests)
304 .define("LLVM_ENABLE_TERMINFO", "OFF")
305 .define("LLVM_ENABLE_LIBEDIT", "OFF")
306 .define("LLVM_ENABLE_BINDINGS", "OFF")
307 .define("LLVM_ENABLE_Z3_SOLVER", "OFF")
308 .define("LLVM_PARALLEL_COMPILE_JOBS", builder.jobs().to_string())
309 .define("LLVM_TARGET_ARCH", target_native.split('-').next().unwrap())
310 .define("LLVM_DEFAULT_TARGET_TRIPLE", target_native);
312 // Parts of our test suite rely on the `FileCheck` tool, which is built by default in
313 // `build/$TARGET/llvm/build/bin` is but *not* then installed to `build/$TARGET/llvm/bin`.
314 // This flag makes sure `FileCheck` is copied in the final binaries directory.
315 cfg.define("LLVM_INSTALL_UTILS", "ON");
317 if builder.config.llvm_profile_generate {
318 cfg.define("LLVM_BUILD_INSTRUMENTED", "IR");
319 if let Ok(llvm_profile_dir) = std::env::var("LLVM_PROFILE_DIR") {
320 cfg.define("LLVM_PROFILE_DATA_DIR", llvm_profile_dir);
322 cfg.define("LLVM_BUILD_RUNTIME", "No");
324 if let Some(path) = builder.config.llvm_profile_use.as_ref() {
325 cfg.define("LLVM_PROFDATA_FILE", &path);
328 if target != "aarch64-apple-darwin" && !target.contains("windows") {
329 cfg.define("LLVM_ENABLE_ZLIB", "ON");
331 cfg.define("LLVM_ENABLE_ZLIB", "OFF");
334 // Are we compiling for iOS/tvOS/watchOS?
335 if target.contains("apple-ios")
336 || target.contains("apple-tvos")
337 || target.contains("apple-watchos")
339 // These two defines prevent CMake from automatically trying to add a MacOSX sysroot, which leads to a compiler error.
340 cfg.define("CMAKE_OSX_SYSROOT", "/");
341 cfg.define("CMAKE_OSX_DEPLOYMENT_TARGET", "");
342 // Prevent cmake from adding -bundle to CFLAGS automatically, which leads to a compiler error because "-bitcode_bundle" also gets added.
343 cfg.define("LLVM_ENABLE_PLUGINS", "OFF");
344 // Zlib fails to link properly, leading to a compiler error.
345 cfg.define("LLVM_ENABLE_ZLIB", "OFF");
348 // This setting makes the LLVM tools link to the dynamic LLVM library,
349 // which saves both memory during parallel links and overall disk space
350 // for the tools. We don't do this on every platform as it doesn't work
351 // equally well everywhere.
353 // If we're not linking rustc to a dynamic LLVM, though, then don't link
355 let llvm_link_shared =
356 builder.llvm_link_tools_dynamically(target) && builder.llvm_link_shared();
357 if llvm_link_shared {
358 cfg.define("LLVM_LINK_LLVM_DYLIB", "ON");
361 if target.starts_with("riscv") && !target.contains("freebsd") {
362 // RISC-V GCC erroneously requires linking against
363 // `libatomic` when using 1-byte and 2-byte C++
364 // atomics but the LLVM build system check cannot
365 // detect this. Therefore it is set manually here.
366 // FreeBSD uses Clang as its system compiler and
367 // provides no libatomic in its base system so does
369 ldflags.exe.push(" -latomic");
370 ldflags.shared.push(" -latomic");
373 if target.contains("msvc") {
374 cfg.define("LLVM_USE_CRT_DEBUG", "MT");
375 cfg.define("LLVM_USE_CRT_RELEASE", "MT");
376 cfg.define("LLVM_USE_CRT_RELWITHDEBINFO", "MT");
377 cfg.static_crt(true);
380 if target.starts_with("i686") {
381 cfg.define("LLVM_BUILD_32_BITS", "ON");
384 let mut enabled_llvm_projects = Vec::new();
386 if util::forcing_clang_based_tests() {
387 enabled_llvm_projects.push("clang");
388 enabled_llvm_projects.push("compiler-rt");
391 if builder.config.llvm_polly {
392 enabled_llvm_projects.push("polly");
395 if builder.config.llvm_clang {
396 enabled_llvm_projects.push("clang");
399 // We want libxml to be disabled.
400 // See https://github.com/rust-lang/rust/pull/50104
401 cfg.define("LLVM_ENABLE_LIBXML2", "OFF");
403 if !enabled_llvm_projects.is_empty() {
404 enabled_llvm_projects.sort();
405 enabled_llvm_projects.dedup();
406 cfg.define("LLVM_ENABLE_PROJECTS", enabled_llvm_projects.join(";"));
409 if let Some(num_linkers) = builder.config.llvm_link_jobs {
411 cfg.define("LLVM_PARALLEL_LINK_JOBS", num_linkers.to_string());
415 // Workaround for ppc32 lld limitation
416 if target == "powerpc-unknown-freebsd" {
417 ldflags.exe.push(" -fuse-ld=bfd");
420 // https://llvm.org/docs/HowToCrossCompileLLVM.html
421 if target != builder.config.build {
422 builder.ensure(Llvm { target: builder.config.build });
423 // FIXME: if the llvm root for the build triple is overridden then we
424 // should use llvm-tblgen from there, also should verify that it
425 // actually exists most of the time in normal installs of LLVM.
426 let host_bin = builder.llvm_out(builder.config.build).join("bin");
427 cfg.define("LLVM_TABLEGEN", host_bin.join("llvm-tblgen").with_extension(EXE_EXTENSION));
428 // LLVM_NM is required for cross compiling using MSVC
429 cfg.define("LLVM_NM", host_bin.join("llvm-nm").with_extension(EXE_EXTENSION));
432 host_bin.join("llvm-config").with_extension(EXE_EXTENSION),
434 if builder.config.llvm_clang {
435 let build_bin = builder.llvm_out(builder.config.build).join("build").join("bin");
436 let clang_tblgen = build_bin.join("clang-tblgen").with_extension(EXE_EXTENSION);
437 if !builder.config.dry_run && !clang_tblgen.exists() {
438 panic!("unable to find {}", clang_tblgen.display());
440 cfg.define("CLANG_TABLEGEN", clang_tblgen);
444 let llvm_version_suffix = if let Some(ref suffix) = builder.config.llvm_version_suffix {
445 // Allow version-suffix="" to not define a version suffix at all.
446 if !suffix.is_empty() { Some(suffix.to_string()) } else { None }
447 } else if builder.config.channel == "dev" {
448 // Changes to a version suffix require a complete rebuild of the LLVM.
449 // To avoid rebuilds during a time of version bump, don't include rustc
450 // release number on the dev channel.
451 Some("-rust-dev".to_string())
453 Some(format!("-rust-{}-{}", builder.version, builder.config.channel))
455 if let Some(ref suffix) = llvm_version_suffix {
456 cfg.define("LLVM_VERSION_SUFFIX", suffix);
459 configure_cmake(builder, target, &mut cfg, true, ldflags);
460 configure_llvm(builder, target, &mut cfg);
462 for (key, val) in &builder.config.llvm_build_config {
463 cfg.define(key, val);
466 // FIXME: we don't actually need to build all LLVM tools and all LLVM
467 // libraries here, e.g., we just want a few components and a few
468 // tools. Figure out how to filter them down and only build the right
469 // tools and libs on all platforms.
471 if builder.config.dry_run {
472 return build_llvm_config;
477 // When building LLVM with LLVM_LINK_LLVM_DYLIB for macOS, an unversioned
478 // libLLVM.dylib will be built. However, llvm-config will still look
479 // for a versioned path like libLLVM-14.dylib. Manually create a symbolic
480 // link to make llvm-config happy.
481 if llvm_link_shared && target.contains("apple-darwin") {
482 let mut cmd = Command::new(&build_llvm_config);
483 let version = output(cmd.arg("--version"));
484 let major = version.split('.').next().unwrap();
485 let lib_name = match llvm_version_suffix {
486 Some(s) => format!("libLLVM-{}{}.dylib", major, s),
487 None => format!("libLLVM-{}.dylib", major),
490 let lib_llvm = out_dir.join("build").join("lib").join(lib_name);
491 if !lib_llvm.exists() {
492 t!(builder.symlink_file("libLLVM.dylib", &lib_llvm));
502 fn check_llvm_version(builder: &Builder<'_>, llvm_config: &Path) {
503 if !builder.config.llvm_version_check {
507 if builder.config.dry_run {
511 let mut cmd = Command::new(llvm_config);
512 let version = output(cmd.arg("--version"));
513 let mut parts = version.split('.').take(2).filter_map(|s| s.parse::<u32>().ok());
514 if let (Some(major), Some(_minor)) = (parts.next(), parts.next()) {
519 panic!("\n\nbad LLVM version: {}, need >=12.0\n\n", version)
523 builder: &Builder<'_>,
524 target: TargetSelection,
525 cfg: &mut cmake::Config,
526 use_compiler_launcher: bool,
527 mut ldflags: LdFlags,
529 // Do not print installation messages for up-to-date files.
530 // LLVM and LLD builds can produce a lot of those and hit CI limits on log size.
531 cfg.define("CMAKE_INSTALL_MESSAGE", "LAZY");
533 // Do not allow the user's value of DESTDIR to influence where
534 // LLVM will install itself. LLVM must always be installed in our
535 // own build directories.
536 cfg.env("DESTDIR", "");
539 cfg.generator("Ninja");
541 cfg.target(&target.triple).host(&builder.config.build.triple);
543 if target != builder.config.build {
544 cfg.define("CMAKE_CROSSCOMPILING", "True");
546 if target.contains("netbsd") {
547 cfg.define("CMAKE_SYSTEM_NAME", "NetBSD");
548 } else if target.contains("freebsd") {
549 cfg.define("CMAKE_SYSTEM_NAME", "FreeBSD");
550 } else if target.contains("windows") {
551 cfg.define("CMAKE_SYSTEM_NAME", "Windows");
552 } else if target.contains("haiku") {
553 cfg.define("CMAKE_SYSTEM_NAME", "Haiku");
554 } else if target.contains("solaris") || target.contains("illumos") {
555 cfg.define("CMAKE_SYSTEM_NAME", "SunOS");
557 // When cross-compiling we should also set CMAKE_SYSTEM_VERSION, but in
558 // that case like CMake we cannot easily determine system version either.
560 // Since, the LLVM itself makes rather limited use of version checks in
561 // CMakeFiles (and then only in tests), and so far no issues have been
562 // reported, the system version is currently left unset.
564 if target.contains("darwin") {
565 // Make sure that CMake does not build universal binaries on macOS.
566 // Explicitly specifiy the one single target architecture.
567 if target.starts_with("aarch64") {
568 // macOS uses a different name for building arm64
569 cfg.define("CMAKE_OSX_ARCHITECTURES", "arm64");
571 cfg.define("CMAKE_OSX_ARCHITECTURES", target.triple.split('-').next().unwrap());
576 let sanitize_cc = |cc: &Path| {
577 if target.contains("msvc") {
578 OsString::from(cc.to_str().unwrap().replace("\\", "/"))
580 cc.as_os_str().to_owned()
584 // MSVC with CMake uses msbuild by default which doesn't respect these
585 // vars that we'd otherwise configure. In that case we just skip this
587 if target.contains("msvc") && !builder.ninja() {
591 let (cc, cxx) = match builder.config.llvm_clang_cl {
592 Some(ref cl) => (cl.as_ref(), cl.as_ref()),
593 None => (builder.cc(target), builder.cxx(target).unwrap()),
596 // Handle msvc + ninja + ccache specially (this is what the bots use)
597 if target.contains("msvc") && builder.ninja() && builder.config.ccache.is_some() {
598 let mut wrap_cc = env::current_exe().expect("failed to get cwd");
599 wrap_cc.set_file_name("sccache-plus-cl.exe");
601 cfg.define("CMAKE_C_COMPILER", sanitize_cc(&wrap_cc))
602 .define("CMAKE_CXX_COMPILER", sanitize_cc(&wrap_cc));
603 cfg.env("SCCACHE_PATH", builder.config.ccache.as_ref().unwrap())
604 .env("SCCACHE_TARGET", target.triple)
605 .env("SCCACHE_CC", &cc)
606 .env("SCCACHE_CXX", &cxx);
608 // Building LLVM on MSVC can be a little ludicrous at times. We're so far
609 // off the beaten path here that I'm not really sure this is even half
610 // supported any more. Here we're trying to:
612 // * Build LLVM on MSVC
613 // * Build LLVM with `clang-cl` instead of `cl.exe`
614 // * Build a project with `sccache`
615 // * Build for 32-bit as well
616 // * Build with Ninja
618 // For `cl.exe` there are different binaries to compile 32/64 bit which
619 // we use but for `clang-cl` there's only one which internally
620 // multiplexes via flags. As a result it appears that CMake's detection
621 // of a compiler's architecture and such on MSVC **doesn't** pass any
622 // custom flags we pass in CMAKE_CXX_FLAGS below. This means that if we
623 // use `clang-cl.exe` it's always diagnosed as a 64-bit compiler which
624 // definitely causes problems since all the env vars are pointing to
627 // To hack around this... again... we pass an argument that's
628 // unconditionally passed in the sccache shim. This'll get CMake to
629 // correctly diagnose it's doing a 32-bit compilation and LLVM will
630 // internally configure itself appropriately.
631 if builder.config.llvm_clang_cl.is_some() && target.contains("i686") {
632 cfg.env("SCCACHE_EXTRA_ARGS", "-m32");
635 // If ccache is configured we inform the build a little differently how
636 // to invoke ccache while also invoking our compilers.
637 if use_compiler_launcher {
638 if let Some(ref ccache) = builder.config.ccache {
639 cfg.define("CMAKE_C_COMPILER_LAUNCHER", ccache)
640 .define("CMAKE_CXX_COMPILER_LAUNCHER", ccache);
643 cfg.define("CMAKE_C_COMPILER", sanitize_cc(cc))
644 .define("CMAKE_CXX_COMPILER", sanitize_cc(cxx))
645 .define("CMAKE_ASM_COMPILER", sanitize_cc(cc));
648 cfg.build_arg("-j").build_arg(builder.jobs().to_string());
649 let mut cflags: OsString = builder.cflags(target, GitRepo::Llvm, CLang::C).join(" ").into();
650 if let Some(ref s) = builder.config.llvm_cflags {
654 // Some compiler features used by LLVM (such as thread locals) will not work on a min version below iOS 10.
655 if target.contains("apple-ios") {
656 if target.contains("86-") {
657 cflags.push(" -miphonesimulator-version-min=10.0");
659 cflags.push(" -miphoneos-version-min=10.0");
662 if builder.config.llvm_clang_cl.is_some() {
663 cflags.push(&format!(" --target={}", target));
665 cfg.define("CMAKE_C_FLAGS", cflags);
666 let mut cxxflags: OsString = builder.cflags(target, GitRepo::Llvm, CLang::Cxx).join(" ").into();
667 if let Some(ref s) = builder.config.llvm_cxxflags {
671 if builder.config.llvm_clang_cl.is_some() {
672 cxxflags.push(&format!(" --target={}", target));
674 cfg.define("CMAKE_CXX_FLAGS", cxxflags);
675 if let Some(ar) = builder.ar(target) {
676 if ar.is_absolute() {
677 // LLVM build breaks if `CMAKE_AR` is a relative path, for some reason it
678 // tries to resolve this path in the LLVM build directory.
679 cfg.define("CMAKE_AR", sanitize_cc(ar));
683 if let Some(ranlib) = builder.ranlib(target) {
684 if ranlib.is_absolute() {
685 // LLVM build breaks if `CMAKE_RANLIB` is a relative path, for some reason it
686 // tries to resolve this path in the LLVM build directory.
687 cfg.define("CMAKE_RANLIB", sanitize_cc(ranlib));
691 if let Some(ref flags) = builder.config.llvm_ldflags {
692 ldflags.push_all(flags);
695 if let Some(flags) = get_var("LDFLAGS", &builder.config.build.triple, &target.triple) {
696 ldflags.push_all(&flags);
699 // For distribution we want the LLVM tools to be *statically* linked to libstdc++.
700 // We also do this if the user explicitly requested static libstdc++.
701 if builder.config.llvm_static_stdcpp {
702 if !target.contains("msvc") && !target.contains("netbsd") && !target.contains("solaris") {
703 if target.contains("apple") || target.contains("windows") {
704 ldflags.push_all("-static-libstdc++");
706 ldflags.push_all("-Wl,-Bsymbolic -static-libstdc++");
711 cfg.define("CMAKE_SHARED_LINKER_FLAGS", &ldflags.shared);
712 cfg.define("CMAKE_MODULE_LINKER_FLAGS", &ldflags.module);
713 cfg.define("CMAKE_EXE_LINKER_FLAGS", &ldflags.exe);
715 if env::var_os("SCCACHE_ERROR_LOG").is_some() {
716 cfg.env("RUSTC_LOG", "sccache=warn");
720 fn configure_llvm(builder: &Builder<'_>, target: TargetSelection, cfg: &mut cmake::Config) {
721 // ThinLTO is only available when building with LLVM, enabling LLD is required.
722 // Apple's linker ld64 supports ThinLTO out of the box though, so don't use LLD on Darwin.
723 if builder.config.llvm_thin_lto {
724 cfg.define("LLVM_ENABLE_LTO", "Thin");
725 if !target.contains("apple") {
726 cfg.define("LLVM_ENABLE_LLD", "ON");
730 if let Some(ref linker) = builder.config.llvm_use_linker {
731 cfg.define("LLVM_USE_LINKER", linker);
734 if builder.config.llvm_allow_old_toolchain {
735 cfg.define("LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN", "YES");
739 // Adapted from https://github.com/alexcrichton/cc-rs/blob/fba7feded71ee4f63cfe885673ead6d7b4f2f454/src/lib.rs#L2347-L2365
740 fn get_var(var_base: &str, host: &str, target: &str) -> Option<OsString> {
741 let kind = if host == target { "HOST" } else { "TARGET" };
742 let target_u = target.replace("-", "_");
743 env::var_os(&format!("{}_{}", var_base, target))
744 .or_else(|| env::var_os(&format!("{}_{}", var_base, target_u)))
745 .or_else(|| env::var_os(&format!("{}_{}", kind, var_base)))
746 .or_else(|| env::var_os(var_base))
749 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
751 pub target: TargetSelection,
755 type Output = PathBuf;
756 const ONLY_HOSTS: bool = true;
758 fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
759 run.path("src/llvm-project/lld")
762 fn make_run(run: RunConfig<'_>) {
763 run.builder.ensure(Lld { target: run.target });
766 /// Compile LLD for `target`.
767 fn run(self, builder: &Builder<'_>) -> PathBuf {
768 if builder.config.dry_run {
769 return PathBuf::from("lld-out-dir-test-gen");
771 let target = self.target;
773 let llvm_config = builder.ensure(Llvm { target: self.target });
775 let out_dir = builder.lld_out(target);
776 let done_stamp = out_dir.join("lld-finished-building");
777 if done_stamp.exists() {
781 builder.info(&format!("Building LLD for {}", target));
782 let _time = util::timeit(&builder);
783 t!(fs::create_dir_all(&out_dir));
785 let mut cfg = cmake::Config::new(builder.src.join("src/llvm-project/lld"));
786 let mut ldflags = LdFlags::default();
788 // When building LLD as part of a build with instrumentation on windows, for example
789 // when doing PGO on CI, cmake or clang-cl don't automatically link clang's
790 // profiler runtime in. In that case, we need to manually ask cmake to do it, to avoid
791 // linking errors, much like LLVM's cmake setup does in that situation.
792 if builder.config.llvm_profile_generate && target.contains("msvc") {
793 if let Some(clang_cl_path) = builder.config.llvm_clang_cl.as_ref() {
794 // Find clang's runtime library directory and push that as a search path to the
795 // cmake linker flags.
796 let clang_rt_dir = get_clang_cl_resource_dir(clang_cl_path);
797 ldflags.push_all(&format!("/libpath:{}", clang_rt_dir.display()));
801 configure_cmake(builder, target, &mut cfg, true, ldflags);
802 configure_llvm(builder, target, &mut cfg);
804 // This is an awful, awful hack. Discovered when we migrated to using
805 // clang-cl to compile LLVM/LLD it turns out that LLD, when built out of
806 // tree, will execute `llvm-config --cmakedir` and then tell CMake about
807 // that directory for later processing. Unfortunately if this path has
808 // forward slashes in it (which it basically always does on Windows)
809 // then CMake will hit a syntax error later on as... something isn't
812 // Instead of attempting to fix this problem in upstream CMake and/or
813 // LLVM/LLD we just hack around it here. This thin wrapper will take the
814 // output from llvm-config and replace all instances of `\` with `/` to
815 // ensure we don't hit the same bugs with escaping. It means that you
816 // can't build on a system where your paths require `\` on Windows, but
817 // there's probably a lot of reasons you can't do that other than this.
818 let llvm_config_shim = env::current_exe().unwrap().with_file_name("llvm-config-wrapper");
820 // Re-use the same flags as llvm to control the level of debug information
821 // generated for lld.
822 let profile = match (builder.config.llvm_optimize, builder.config.llvm_release_debuginfo) {
823 (false, _) => "Debug",
824 (true, false) => "Release",
825 (true, true) => "RelWithDebInfo",
828 cfg.out_dir(&out_dir)
830 .env("LLVM_CONFIG_REAL", &llvm_config)
831 .define("LLVM_CONFIG_PATH", llvm_config_shim)
832 .define("LLVM_INCLUDE_TESTS", "OFF");
834 // While we're using this horrible workaround to shim the execution of
835 // llvm-config, let's just pile on more. I can't seem to figure out how
836 // to build LLD as a standalone project and also cross-compile it at the
837 // same time. It wants a natively executable `llvm-config` to learn
838 // about LLVM, but then it learns about all the host configuration of
839 // LLVM and tries to link to host LLVM libraries.
841 // To work around that we tell our shim to replace anything with the
842 // build target with the actual target instead. This'll break parts of
843 // LLD though which try to execute host tools, such as llvm-tblgen, so
844 // we specifically tell it where to find those. This is likely super
845 // brittle and will break over time. If anyone knows better how to
846 // cross-compile LLD it would be much appreciated to fix this!
847 if target != builder.config.build {
848 cfg.env("LLVM_CONFIG_SHIM_REPLACE", &builder.config.build.triple)
849 .env("LLVM_CONFIG_SHIM_REPLACE_WITH", &target.triple)
852 llvm_config.with_file_name("llvm-tblgen").with_extension(EXE_EXTENSION),
856 // Explicitly set C++ standard, because upstream doesn't do so
857 // for standalone builds.
858 cfg.define("CMAKE_CXX_STANDARD", "14");
862 t!(File::create(&done_stamp));
867 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
868 pub struct TestHelpers {
869 pub target: TargetSelection,
872 impl Step for TestHelpers {
875 fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
876 run.path("src/test/auxiliary/rust_test_helpers.c")
879 fn make_run(run: RunConfig<'_>) {
880 run.builder.ensure(TestHelpers { target: run.target })
883 /// Compiles the `rust_test_helpers.c` library which we used in various
884 /// `run-pass` tests for ABI testing.
885 fn run(self, builder: &Builder<'_>) {
886 if builder.config.dry_run {
889 // The x86_64-fortanix-unknown-sgx target doesn't have a working C
890 // toolchain. However, some x86_64 ELF objects can be linked
891 // without issues. Use this hack to compile the test helpers.
892 let target = if self.target == "x86_64-fortanix-unknown-sgx" {
893 TargetSelection::from_user("x86_64-unknown-linux-gnu")
897 let dst = builder.test_helpers_out(target);
898 let src = builder.src.join("src/test/auxiliary/rust_test_helpers.c");
899 if up_to_date(&src, &dst.join("librust_test_helpers.a")) {
903 builder.info("Building test helpers");
904 t!(fs::create_dir_all(&dst));
905 let mut cfg = cc::Build::new();
906 // FIXME: Workaround for https://github.com/emscripten-core/emscripten/issues/9013
907 if target.contains("emscripten") {
911 // We may have found various cross-compilers a little differently due to our
912 // extra configuration, so inform cc of these compilers. Note, though, that
913 // on MSVC we still need cc's detection of env vars (ugh).
914 if !target.contains("msvc") {
915 if let Some(ar) = builder.ar(target) {
918 cfg.compiler(builder.cc(target));
920 cfg.cargo_metadata(false)
922 .target(&target.triple)
923 .host(&builder.config.build.triple)
927 .file(builder.src.join("src/test/auxiliary/rust_test_helpers.c"))
928 .compile("rust_test_helpers");
932 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
933 pub struct Sanitizers {
934 pub target: TargetSelection,
937 impl Step for Sanitizers {
938 type Output = Vec<SanitizerRuntime>;
940 fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
941 run.alias("sanitizers")
944 fn make_run(run: RunConfig<'_>) {
945 run.builder.ensure(Sanitizers { target: run.target });
948 /// Builds sanitizer runtime libraries.
949 fn run(self, builder: &Builder<'_>) -> Self::Output {
950 let compiler_rt_dir = builder.src.join("src/llvm-project/compiler-rt");
951 if !compiler_rt_dir.exists() {
955 let out_dir = builder.native_dir(self.target).join("sanitizers");
956 let runtimes = supported_sanitizers(&out_dir, self.target, &builder.config.channel);
957 if runtimes.is_empty() {
961 let llvm_config = builder.ensure(Llvm { target: builder.config.build });
962 if builder.config.dry_run {
966 let stamp = out_dir.join("sanitizers-finished-building");
967 let stamp = HashStamp::new(stamp, builder.in_tree_llvm_info.sha());
970 if stamp.hash.is_none() {
971 builder.info(&format!(
972 "Rebuild sanitizers by removing the file `{}`",
979 builder.info(&format!("Building sanitizers for {}", self.target));
981 let _time = util::timeit(&builder);
983 let mut cfg = cmake::Config::new(&compiler_rt_dir);
984 cfg.profile("Release");
985 cfg.define("CMAKE_C_COMPILER_TARGET", self.target.triple);
986 cfg.define("COMPILER_RT_BUILD_BUILTINS", "OFF");
987 cfg.define("COMPILER_RT_BUILD_CRT", "OFF");
988 cfg.define("COMPILER_RT_BUILD_LIBFUZZER", "OFF");
989 cfg.define("COMPILER_RT_BUILD_PROFILE", "OFF");
990 cfg.define("COMPILER_RT_BUILD_SANITIZERS", "ON");
991 cfg.define("COMPILER_RT_BUILD_XRAY", "OFF");
992 cfg.define("COMPILER_RT_DEFAULT_TARGET_ONLY", "ON");
993 cfg.define("COMPILER_RT_USE_LIBCXX", "OFF");
994 cfg.define("LLVM_CONFIG_PATH", &llvm_config);
996 // On Darwin targets the sanitizer runtimes are build as universal binaries.
997 // Unfortunately sccache currently lacks support to build them successfully.
998 // Disable compiler launcher on Darwin targets to avoid potential issues.
999 let use_compiler_launcher = !self.target.contains("apple-darwin");
1000 configure_cmake(builder, self.target, &mut cfg, use_compiler_launcher, LdFlags::default());
1002 t!(fs::create_dir_all(&out_dir));
1003 cfg.out_dir(out_dir);
1005 for runtime in &runtimes {
1006 cfg.build_target(&runtime.cmake_target);
1015 #[derive(Clone, Debug)]
1016 pub struct SanitizerRuntime {
1017 /// CMake target used to build the runtime.
1018 pub cmake_target: String,
1019 /// Path to the built runtime library.
1021 /// Library filename that will be used rustc.
1025 /// Returns sanitizers available on a given target.
1026 fn supported_sanitizers(
1028 target: TargetSelection,
1030 ) -> Vec<SanitizerRuntime> {
1031 let darwin_libs = |os: &str, components: &[&str]| -> Vec<SanitizerRuntime> {
1034 .map(move |c| SanitizerRuntime {
1035 cmake_target: format!("clang_rt.{}_{}_dynamic", c, os),
1037 .join(&format!("build/lib/darwin/libclang_rt.{}_{}_dynamic.dylib", c, os)),
1038 name: format!("librustc-{}_rt.{}.dylib", channel, c),
1043 let common_libs = |os: &str, arch: &str, components: &[&str]| -> Vec<SanitizerRuntime> {
1046 .map(move |c| SanitizerRuntime {
1047 cmake_target: format!("clang_rt.{}-{}", c, arch),
1048 path: out_dir.join(&format!("build/lib/{}/libclang_rt.{}-{}.a", os, c, arch)),
1049 name: format!("librustc-{}_rt.{}.a", channel, c),
1054 match &*target.triple {
1055 "aarch64-apple-darwin" => darwin_libs("osx", &["asan", "lsan", "tsan"]),
1056 "aarch64-fuchsia" => common_libs("fuchsia", "aarch64", &["asan"]),
1057 "aarch64-unknown-linux-gnu" => {
1058 common_libs("linux", "aarch64", &["asan", "lsan", "msan", "tsan", "hwasan"])
1060 "x86_64-apple-darwin" => darwin_libs("osx", &["asan", "lsan", "tsan"]),
1061 "x86_64-fuchsia" => common_libs("fuchsia", "x86_64", &["asan"]),
1062 "x86_64-unknown-freebsd" => common_libs("freebsd", "x86_64", &["asan", "msan", "tsan"]),
1063 "x86_64-unknown-netbsd" => {
1064 common_libs("netbsd", "x86_64", &["asan", "lsan", "msan", "tsan"])
1066 "x86_64-unknown-illumos" => common_libs("illumos", "x86_64", &["asan"]),
1067 "x86_64-pc-solaris" => common_libs("solaris", "x86_64", &["asan"]),
1068 "x86_64-unknown-linux-gnu" => {
1069 common_libs("linux", "x86_64", &["asan", "lsan", "msan", "tsan"])
1071 "x86_64-unknown-linux-musl" => {
1072 common_libs("linux", "x86_64", &["asan", "lsan", "msan", "tsan"])
1080 hash: Option<Vec<u8>>,
1084 fn new(path: PathBuf, hash: Option<&str>) -> Self {
1085 HashStamp { path, hash: hash.map(|s| s.as_bytes().to_owned()) }
1088 fn is_done(&self) -> bool {
1089 match fs::read(&self.path) {
1090 Ok(h) => self.hash.as_deref().unwrap_or(b"") == h.as_slice(),
1091 Err(e) if e.kind() == io::ErrorKind::NotFound => false,
1093 panic!("failed to read stamp file `{}`: {}", self.path.display(), e);
1098 fn remove(&self) -> io::Result<()> {
1099 match fs::remove_file(&self.path) {
1102 if e.kind() == io::ErrorKind::NotFound {
1111 fn write(&self) -> io::Result<()> {
1112 fs::write(&self.path, self.hash.as_deref().unwrap_or(b""))
1116 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
1117 pub struct CrtBeginEnd {
1118 pub target: TargetSelection,
1121 impl Step for CrtBeginEnd {
1122 type Output = PathBuf;
1124 fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
1125 run.path("src/llvm-project/compiler-rt/lib/crt")
1128 fn make_run(run: RunConfig<'_>) {
1129 run.builder.ensure(CrtBeginEnd { target: run.target });
1132 /// Build crtbegin.o/crtend.o for musl target.
1133 fn run(self, builder: &Builder<'_>) -> Self::Output {
1134 let out_dir = builder.native_dir(self.target).join("crt");
1136 if builder.config.dry_run {
1140 let crtbegin_src = builder.src.join("src/llvm-project/compiler-rt/lib/crt/crtbegin.c");
1141 let crtend_src = builder.src.join("src/llvm-project/compiler-rt/lib/crt/crtend.c");
1142 if up_to_date(&crtbegin_src, &out_dir.join("crtbegin.o"))
1143 && up_to_date(&crtend_src, &out_dir.join("crtendS.o"))
1148 builder.info("Building crtbegin.o and crtend.o");
1149 t!(fs::create_dir_all(&out_dir));
1151 let mut cfg = cc::Build::new();
1153 if let Some(ar) = builder.ar(self.target) {
1156 cfg.compiler(builder.cc(self.target));
1157 cfg.cargo_metadata(false)
1159 .target(&self.target.triple)
1160 .host(&builder.config.build.triple)
1167 // Those flags are defined in src/llvm-project/compiler-rt/lib/crt/CMakeLists.txt
1168 // Currently only consumer of those objects is musl, which use .init_array/.fini_array
1169 // instead of .ctors/.dtors
1170 cfg.flag("-std=c11")
1171 .define("CRT_HAS_INITFINI_ARRAY", None)
1172 .define("EH_USE_FRAME_REGISTRY", None);
1176 t!(fs::copy(out_dir.join("crtbegin.o"), out_dir.join("crtbeginS.o")));
1177 t!(fs::copy(out_dir.join("crtend.o"), out_dir.join("crtendS.o")));
1182 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
1183 pub struct Libunwind {
1184 pub target: TargetSelection,
1187 impl Step for Libunwind {
1188 type Output = PathBuf;
1190 fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
1191 run.path("src/llvm-project/libunwind")
1194 fn make_run(run: RunConfig<'_>) {
1195 run.builder.ensure(Libunwind { target: run.target });
1198 /// Build linunwind.a
1199 fn run(self, builder: &Builder<'_>) -> Self::Output {
1200 if builder.config.dry_run {
1201 return PathBuf::new();
1204 let out_dir = builder.native_dir(self.target).join("libunwind");
1205 let root = builder.src.join("src/llvm-project/libunwind");
1207 if up_to_date(&root, &out_dir.join("libunwind.a")) {
1211 builder.info(&format!("Building libunwind.a for {}", self.target.triple));
1212 t!(fs::create_dir_all(&out_dir));
1214 let mut cc_cfg = cc::Build::new();
1215 let mut cpp_cfg = cc::Build::new();
1218 cpp_cfg.cpp_set_stdlib(None);
1219 cpp_cfg.flag("-nostdinc++");
1220 cpp_cfg.flag("-fno-exceptions");
1221 cpp_cfg.flag("-fno-rtti");
1222 cpp_cfg.flag_if_supported("-fvisibility-global-new-delete-hidden");
1224 for cfg in [&mut cc_cfg, &mut cpp_cfg].iter_mut() {
1225 if let Some(ar) = builder.ar(self.target) {
1228 cfg.target(&self.target.triple);
1229 cfg.host(&builder.config.build.triple);
1230 cfg.warnings(false);
1232 // get_compiler() need set opt_level first.
1234 cfg.flag("-fstrict-aliasing");
1235 cfg.flag("-funwind-tables");
1236 cfg.flag("-fvisibility=hidden");
1237 cfg.define("_LIBUNWIND_DISABLE_VISIBILITY_ANNOTATIONS", None);
1238 cfg.include(root.join("include"));
1239 cfg.cargo_metadata(false);
1240 cfg.out_dir(&out_dir);
1242 if self.target.contains("x86_64-fortanix-unknown-sgx") {
1243 cfg.static_flag(true);
1244 cfg.flag("-fno-stack-protector");
1245 cfg.flag("-ffreestanding");
1246 cfg.flag("-fexceptions");
1248 // easiest way to undefine since no API available in cc::Build to undefine
1249 cfg.flag("-U_FORTIFY_SOURCE");
1250 cfg.define("_FORTIFY_SOURCE", "0");
1251 cfg.define("RUST_SGX", "1");
1252 cfg.define("__NO_STRING_INLINES", None);
1253 cfg.define("__NO_MATH_INLINES", None);
1254 cfg.define("_LIBUNWIND_IS_BAREMETAL", None);
1255 cfg.define("__LIBUNWIND_IS_NATIVE_ONLY", None);
1256 cfg.define("NDEBUG", None);
1258 if self.target.contains("windows") {
1259 cfg.define("_LIBUNWIND_HIDE_SYMBOLS", "1");
1260 cfg.define("_LIBUNWIND_IS_NATIVE_ONLY", "1");
1264 cc_cfg.compiler(builder.cc(self.target));
1265 if let Ok(cxx) = builder.cxx(self.target) {
1266 cpp_cfg.compiler(cxx);
1268 cc_cfg.compiler(builder.cc(self.target));
1271 // Don't set this for clang
1272 // By default, Clang builds C code in GNU C17 mode.
1273 // By default, Clang builds C++ code according to the C++98 standard,
1274 // with many C++11 features accepted as extensions.
1275 if cc_cfg.get_compiler().is_like_gnu() {
1276 cc_cfg.flag("-std=c99");
1278 if cpp_cfg.get_compiler().is_like_gnu() {
1279 cpp_cfg.flag("-std=c++11");
1282 if self.target.contains("x86_64-fortanix-unknown-sgx") || self.target.contains("musl") {
1283 // use the same GCC C compiler command to compile C++ code so we do not need to setup the
1284 // C++ compiler env variables on the builders.
1285 // Don't set this for clang++, as clang++ is able to compile this without libc++.
1286 if cpp_cfg.get_compiler().is_like_gnu() {
1288 cpp_cfg.compiler(builder.cc(self.target));
1292 let mut c_sources = vec![
1294 "UnwindLevel1-gcc-ext.c",
1296 "UnwindRegistersRestore.S",
1297 "UnwindRegistersSave.S",
1300 let cpp_sources = vec!["Unwind-EHABI.cpp", "Unwind-seh.cpp", "libunwind.cpp"];
1301 let cpp_len = cpp_sources.len();
1303 if self.target.contains("x86_64-fortanix-unknown-sgx") {
1304 c_sources.push("UnwindRustSgx.c");
1307 for src in c_sources {
1308 cc_cfg.file(root.join("src").join(src).canonicalize().unwrap());
1311 for src in &cpp_sources {
1312 cpp_cfg.file(root.join("src").join(src).canonicalize().unwrap());
1315 cpp_cfg.compile("unwind-cpp");
1317 // FIXME: https://github.com/alexcrichton/cc-rs/issues/545#issuecomment-679242845
1319 for entry in fs::read_dir(&out_dir).unwrap() {
1320 let file = entry.unwrap().path().canonicalize().unwrap();
1321 if file.is_file() && file.extension() == Some(OsStr::new("o")) {
1322 // file name starts with "Unwind-EHABI", "Unwind-seh" or "libunwind"
1323 let file_name = file.file_name().unwrap().to_str().expect("UTF-8 file name");
1324 if cpp_sources.iter().any(|f| file_name.starts_with(&f[..f.len() - 4])) {
1325 cc_cfg.object(&file);
1330 assert_eq!(cpp_len, count, "Can't get object files from {:?}", &out_dir);
1332 cc_cfg.compile("unwind");