1 //! Shim which is passed to Cargo as "rustc" when running the bootstrap.
3 //! This shim will take care of some various tasks that our build process
4 //! requires that Cargo can't quite do through normal configuration:
6 //! 1. When compiling build scripts and build dependencies, we need a guaranteed
7 //! full standard library available. The only compiler which actually has
8 //! this is the snapshot, so we detect this situation and always compile with
9 //! the snapshot compiler.
10 //! 2. We pass a bunch of `--cfg` and other flags based on what we're compiling
11 //! (and this slightly differs based on a whether we're using a snapshot or
12 //! not), so we do that all here.
14 //! This may one day be replaced by RUSTFLAGS, but the dynamic nature of
15 //! switching compilers for the bootstrap and for build scripts will probably
16 //! never get replaced.
18 include!("../dylib_util.rs");
21 use std::path::PathBuf;
22 use std::process::{Child, Command};
23 use std::str::FromStr;
24 use std::time::Instant;
27 let args = env::args_os().skip(1).collect::<Vec<_>>();
29 // Detect whether or not we're a build script depending on whether --target
30 // is passed (a bit janky...)
31 let target = args.windows(2).find(|w| &*w[0] == "--target").and_then(|w| w[1].to_str());
32 let version = args.iter().find(|w| &**w == "-vV");
34 let verbose = match env::var("RUSTC_VERBOSE") {
35 Ok(s) => usize::from_str(&s).expect("RUSTC_VERBOSE should be an integer"),
39 // Use a different compiler for build scripts, since there may not yet be a
40 // libstd for the real compiler to use. However, if Cargo is attempting to
41 // determine the version of the compiler, the real compiler needs to be
42 // used. Currently, these two states are differentiated based on whether
43 // --target and -vV is/isn't passed.
44 let (rustc, libdir) = if target.is_none() && version.is_none() {
45 ("RUSTC_SNAPSHOT", "RUSTC_SNAPSHOT_LIBDIR")
47 ("RUSTC_REAL", "RUSTC_LIBDIR")
49 let stage = env::var("RUSTC_STAGE").expect("RUSTC_STAGE was not set");
50 let sysroot = env::var_os("RUSTC_SYSROOT").expect("RUSTC_SYSROOT was not set");
51 let on_fail = env::var_os("RUSTC_ON_FAIL").map(Command::new);
53 let rustc = env::var_os(rustc).unwrap_or_else(|| panic!("{:?} was not set", rustc));
54 let libdir = env::var_os(libdir).unwrap_or_else(|| panic!("{:?} was not set", libdir));
55 let mut dylib_path = dylib_path();
56 dylib_path.insert(0, PathBuf::from(&libdir));
58 let mut cmd = Command::new(rustc);
59 cmd.args(&args).env(dylib_path_var(), env::join_paths(&dylib_path).unwrap());
61 // Get the name of the crate we're compiling, if any.
63 args.windows(2).find(|args| args[0] == "--crate-name").and_then(|args| args[1].to_str());
65 if let Some(crate_name) = crate_name {
66 if let Some(target) = env::var_os("RUSTC_TIME") {
68 || target.into_string().unwrap().split(',').any(|c| c.trim() == crate_name)
75 // Print backtrace in case of ICE
76 if env::var("RUSTC_BACKTRACE_ON_ICE").is_ok() && env::var("RUST_BACKTRACE").is_err() {
77 cmd.env("RUST_BACKTRACE", "1");
80 if let Ok(lint_flags) = env::var("RUSTC_LINT_FLAGS") {
81 cmd.args(lint_flags.split_whitespace());
85 // The stage0 compiler has a special sysroot distinct from what we
86 // actually downloaded, so we just always pass the `--sysroot` option,
87 // unless one is already set.
88 if !args.iter().any(|arg| arg == "--sysroot") {
89 cmd.arg("--sysroot").arg(&sysroot);
92 // If we're compiling specifically the `panic_abort` crate then we pass
93 // the `-C panic=abort` option. Note that we do not do this for any
94 // other crate intentionally as this is the only crate for now that we
95 // ship with panic=abort.
97 // This... is a bit of a hack how we detect this. Ideally this
98 // information should be encoded in the crate I guess? Would likely
99 // require an RFC amendment to RFC 1513, however.
101 // `compiler_builtins` are unconditionally compiled with panic=abort to
102 // workaround undefined references to `rust_eh_unwind_resume` generated
103 // otherwise, see issue https://github.com/rust-lang/rust/issues/43095.
104 if crate_name == Some("panic_abort")
105 || crate_name == Some("compiler_builtins") && stage != "0"
107 cmd.arg("-C").arg("panic=abort");
110 // FIXME(rust-lang/cargo#5754) we shouldn't be using special env vars
111 // here, but rather Cargo should know what flags to pass rustc itself.
113 // Override linker if necessary.
114 if let Ok(host_linker) = env::var("RUSTC_HOST_LINKER") {
115 cmd.arg(format!("-Clinker={}", host_linker));
117 if env::var_os("RUSTC_HOST_FUSE_LD_LLD").is_some() {
118 cmd.arg("-Clink-args=-fuse-ld=lld");
121 if let Ok(s) = env::var("RUSTC_HOST_CRT_STATIC") {
123 cmd.arg("-C").arg("target-feature=+crt-static");
126 cmd.arg("-C").arg("target-feature=-crt-static");
130 // Cargo doesn't pass RUSTFLAGS to proc_macros:
131 // https://github.com/rust-lang/cargo/issues/4423
132 // Thus, if we are on stage 0, we explicitly set `--cfg=bootstrap`.
133 // We also declare that the flag is expected, which is mainly needed for
134 // later stages so that they don't warn about #[cfg(bootstrap)],
135 // but enabling it for stage 0 too lets any warnings, if they occur,
136 // occur more early on, e.g. about #[cfg(bootstrap = "foo")].
138 cmd.arg("--cfg=bootstrap");
140 cmd.arg("-Zunstable-options");
141 cmd.arg("--check-cfg=values(bootstrap)");
144 if let Ok(map) = env::var("RUSTC_DEBUGINFO_MAP") {
145 cmd.arg("--remap-path-prefix").arg(&map);
148 // Force all crates compiled by this compiler to (a) be unstable and (b)
149 // allow the `rustc_private` feature to link to other unstable crates
150 // also in the sysroot. We also do this for host crates, since those
151 // may be proc macros, in which case we might ship them.
152 if env::var_os("RUSTC_FORCE_UNSTABLE").is_some() && (stage != "0" || target.is_some()) {
153 cmd.arg("-Z").arg("force-unstable-if-unmarked");
156 if let Ok(flags) = env::var("MAGIC_EXTRA_RUSTFLAGS") {
157 for flag in flags.split(' ') {
162 let is_test = args.iter().any(|a| a == "--test");
165 env::vars().filter(|(k, _)| k.starts_with("RUST") || k.starts_with("CARGO"));
166 let prefix = if is_test { "[RUSTC-SHIM] rustc --test" } else { "[RUSTC-SHIM] rustc" };
167 let prefix = match crate_name {
168 Some(crate_name) => format!("{} {}", prefix, crate_name),
169 None => prefix.to_string(),
171 for (i, (k, v)) in rust_env_vars.enumerate() {
172 eprintln!("{} env[{}]: {:?}={:?}", prefix, i, k, v);
174 eprintln!("{} working directory: {}", prefix, env::current_dir().unwrap().display());
176 "{} command: {:?}={:?} {:?}",
179 env::join_paths(&dylib_path).unwrap(),
182 eprintln!("{} sysroot: {:?}", prefix, sysroot);
183 eprintln!("{} libdir: {:?}", prefix, libdir);
186 let start = Instant::now();
187 let (child, status) = {
188 let errmsg = format!("\nFailed to run:\n{:?}\n-------------", cmd);
189 let mut child = cmd.spawn().expect(&errmsg);
190 let status = child.wait().expect(&errmsg);
194 if env::var_os("RUSTC_PRINT_STEP_TIMINGS").is_some()
195 || env::var_os("RUSTC_PRINT_STEP_RUSAGE").is_some()
197 if let Some(crate_name) = crate_name {
198 let dur = start.elapsed();
199 // If the user requested resource usage data, then
200 // include that in addition to the timing output.
202 env::var_os("RUSTC_PRINT_STEP_RUSAGE").and_then(|_| format_rusage_data(child));
204 "[RUSTC-TIMING] {} test:{} {}.{:03}{}{}",
209 if rusage_data.is_some() { " " } else { "" },
210 rusage_data.unwrap_or(String::new()),
215 if status.success() {
216 std::process::exit(0);
217 // note: everything below here is unreachable. do not put code that
218 // should run on success, after this block.
221 println!("\nDid not run successfully: {}\n{:?}\n-------------", status, cmd);
224 if let Some(mut on_fail) = on_fail {
225 on_fail.status().expect("Could not run the on_fail command");
228 // Preserve the exit code. In case of signal, exit with 0xfe since it's
229 // awkward to preserve this status in a cross-platform way.
230 match status.code() {
231 Some(i) => std::process::exit(i),
233 eprintln!("rustc exited with {}", status);
234 std::process::exit(0xfe);
239 #[cfg(all(not(unix), not(windows)))]
240 // In the future we can add this for more platforms
241 fn format_rusage_data(_child: Child) -> Option<String> {
246 fn format_rusage_data(child: Child) -> Option<String> {
247 use std::os::windows::io::AsRawHandle;
248 use winapi::um::{processthreadsapi, psapi, timezoneapi};
249 let handle = child.as_raw_handle();
250 macro_rules! try_bool {
258 let mut user_filetime = Default::default();
259 let mut user_time = Default::default();
260 let mut kernel_filetime = Default::default();
261 let mut kernel_time = Default::default();
262 let mut memory_counters = psapi::PROCESS_MEMORY_COUNTERS::default();
265 try_bool!(processthreadsapi::GetProcessTimes(
267 &mut Default::default(),
268 &mut Default::default(),
269 &mut kernel_filetime,
272 try_bool!(timezoneapi::FileTimeToSystemTime(&user_filetime, &mut user_time));
273 try_bool!(timezoneapi::FileTimeToSystemTime(&kernel_filetime, &mut kernel_time));
275 // Unlike on Linux with RUSAGE_CHILDREN, this will only return memory information for the process
276 // with the given handle and none of that process's children.
277 try_bool!(psapi::GetProcessMemoryInfo(
279 &mut memory_counters as *mut _ as _,
280 std::mem::size_of::<psapi::PROCESS_MEMORY_COUNTERS_EX>() as u32,
284 // Guide on interpreting these numbers:
285 // https://docs.microsoft.com/en-us/windows/win32/psapi/process-memory-usage-information
286 let peak_working_set = memory_counters.PeakWorkingSetSize / 1024;
287 let peak_page_file = memory_counters.PeakPagefileUsage / 1024;
288 let peak_paged_pool = memory_counters.QuotaPeakPagedPoolUsage / 1024;
289 let peak_nonpaged_pool = memory_counters.QuotaPeakNonPagedPoolUsage / 1024;
291 "user: {USER_SEC}.{USER_USEC:03} \
292 sys: {SYS_SEC}.{SYS_USEC:03} \
293 peak working set (kb): {PEAK_WORKING_SET} \
294 peak page file usage (kb): {PEAK_PAGE_FILE} \
295 peak paged pool usage (kb): {PEAK_PAGED_POOL} \
296 peak non-paged pool usage (kb): {PEAK_NONPAGED_POOL} \
297 page faults: {PAGE_FAULTS}",
298 USER_SEC = user_time.wSecond + (user_time.wMinute * 60),
299 USER_USEC = user_time.wMilliseconds,
300 SYS_SEC = kernel_time.wSecond + (kernel_time.wMinute * 60),
301 SYS_USEC = kernel_time.wMilliseconds,
302 PEAK_WORKING_SET = peak_working_set,
303 PEAK_PAGE_FILE = peak_page_file,
304 PEAK_PAGED_POOL = peak_paged_pool,
305 PEAK_NONPAGED_POOL = peak_nonpaged_pool,
306 PAGE_FAULTS = memory_counters.PageFaultCount,
311 /// Tries to build a string with human readable data for several of the rusage
312 /// fields. Note that we are focusing mainly on data that we believe to be
313 /// supplied on Linux (the `rusage` struct has other fields in it but they are
314 /// currently unsupported by Linux).
315 fn format_rusage_data(_child: Child) -> Option<String> {
316 let rusage: libc::rusage = unsafe {
317 let mut recv = std::mem::zeroed();
318 // -1 is RUSAGE_CHILDREN, which means to get the rusage for all children
319 // (and grandchildren, etc) processes that have respectively terminated
320 // and been waited for.
321 let retval = libc::getrusage(-1, &mut recv);
327 // Mac OS X reports the maxrss in bytes, not kb.
328 let divisor = if env::consts::OS == "macos" { 1024 } else { 1 };
329 let maxrss = (rusage.ru_maxrss + (divisor - 1)) / divisor;
331 let mut init_str = format!(
332 "user: {USER_SEC}.{USER_USEC:03} \
333 sys: {SYS_SEC}.{SYS_USEC:03} \
334 max rss (kb): {MAXRSS}",
335 USER_SEC = rusage.ru_utime.tv_sec,
336 USER_USEC = rusage.ru_utime.tv_usec,
337 SYS_SEC = rusage.ru_stime.tv_sec,
338 SYS_USEC = rusage.ru_stime.tv_usec,
342 // The remaining rusage stats vary in platform support. So we treat
343 // uniformly zero values in each category as "not worth printing", since it
344 // either means no events of that type occurred, or that the platform
345 // does not support it.
347 let minflt = rusage.ru_minflt;
348 let majflt = rusage.ru_majflt;
349 if minflt != 0 || majflt != 0 {
350 init_str.push_str(&format!(" page reclaims: {} page faults: {}", minflt, majflt));
353 let inblock = rusage.ru_inblock;
354 let oublock = rusage.ru_oublock;
355 if inblock != 0 || oublock != 0 {
356 init_str.push_str(&format!(" fs block inputs: {} fs block outputs: {}", inblock, oublock));
359 let nvcsw = rusage.ru_nvcsw;
360 let nivcsw = rusage.ru_nivcsw;
361 if nvcsw != 0 || nivcsw != 0 {
362 init_str.push_str(&format!(
363 " voluntary ctxt switches: {} involuntary ctxt switches: {}",
368 return Some(init_str);