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.
19 use std::path::PathBuf;
20 use std::process::{Child, Command};
21 use std::str::FromStr;
22 use std::time::Instant;
25 let args = env::args_os().skip(1).collect::<Vec<_>>();
27 // Detect whether or not we're a build script depending on whether --target
28 // is passed (a bit janky...)
29 let target = args.windows(2).find(|w| &*w[0] == "--target").and_then(|w| w[1].to_str());
30 let version = args.iter().find(|w| &**w == "-vV");
32 let verbose = match env::var("RUSTC_VERBOSE") {
33 Ok(s) => usize::from_str(&s).expect("RUSTC_VERBOSE should be an integer"),
37 // Use a different compiler for build scripts, since there may not yet be a
38 // libstd for the real compiler to use. However, if Cargo is attempting to
39 // determine the version of the compiler, the real compiler needs to be
40 // used. Currently, these two states are differentiated based on whether
41 // --target and -vV is/isn't passed.
42 let (rustc, libdir) = if target.is_none() && version.is_none() {
43 ("RUSTC_SNAPSHOT", "RUSTC_SNAPSHOT_LIBDIR")
45 ("RUSTC_REAL", "RUSTC_LIBDIR")
47 let stage = env::var("RUSTC_STAGE").expect("RUSTC_STAGE was not set");
48 let sysroot = env::var_os("RUSTC_SYSROOT").expect("RUSTC_SYSROOT was not set");
49 let on_fail = env::var_os("RUSTC_ON_FAIL").map(Command::new);
51 let rustc = env::var_os(rustc).unwrap_or_else(|| panic!("{:?} was not set", rustc));
52 let libdir = env::var_os(libdir).unwrap_or_else(|| panic!("{:?} was not set", libdir));
53 let mut dylib_path = bootstrap::util::dylib_path();
54 dylib_path.insert(0, PathBuf::from(&libdir));
56 let mut cmd = Command::new(rustc);
57 cmd.args(&args).env(bootstrap::util::dylib_path_var(), env::join_paths(&dylib_path).unwrap());
59 // Get the name of the crate we're compiling, if any.
61 args.windows(2).find(|args| args[0] == "--crate-name").and_then(|args| args[1].to_str());
63 if let Some(crate_name) = crate_name {
64 if let Some(target) = env::var_os("RUSTC_TIME") {
66 || target.into_string().unwrap().split(',').any(|c| c.trim() == crate_name)
73 // Print backtrace in case of ICE
74 if env::var("RUSTC_BACKTRACE_ON_ICE").is_ok() && env::var("RUST_BACKTRACE").is_err() {
75 cmd.env("RUST_BACKTRACE", "1");
78 if let Ok(lint_flags) = env::var("RUSTC_LINT_FLAGS") {
79 cmd.args(lint_flags.split_whitespace());
83 // The stage0 compiler has a special sysroot distinct from what we
84 // actually downloaded, so we just always pass the `--sysroot` option,
85 // unless one is already set.
86 if !args.iter().any(|arg| arg == "--sysroot") {
87 cmd.arg("--sysroot").arg(&sysroot);
90 // If we're compiling specifically the `panic_abort` crate then we pass
91 // the `-C panic=abort` option. Note that we do not do this for any
92 // other crate intentionally as this is the only crate for now that we
93 // ship with panic=abort.
95 // This... is a bit of a hack how we detect this. Ideally this
96 // information should be encoded in the crate I guess? Would likely
97 // require an RFC amendment to RFC 1513, however.
99 // `compiler_builtins` are unconditionally compiled with panic=abort to
100 // workaround undefined references to `rust_eh_unwind_resume` generated
101 // otherwise, see issue https://github.com/rust-lang/rust/issues/43095.
102 if crate_name == Some("panic_abort")
103 || crate_name == Some("compiler_builtins") && stage != "0"
105 cmd.arg("-C").arg("panic=abort");
108 // FIXME(rust-lang/cargo#5754) we shouldn't be using special env vars
109 // here, but rather Cargo should know what flags to pass rustc itself.
111 // Override linker if necessary.
112 if let Ok(host_linker) = env::var("RUSTC_HOST_LINKER") {
113 cmd.arg(format!("-Clinker={}", host_linker));
115 if env::var_os("RUSTC_HOST_FUSE_LD_LLD").is_some() {
116 cmd.arg("-Clink-args=-fuse-ld=lld");
119 if let Ok(s) = env::var("RUSTC_HOST_CRT_STATIC") {
121 cmd.arg("-C").arg("target-feature=+crt-static");
124 cmd.arg("-C").arg("target-feature=-crt-static");
129 // Cargo doesn't pass RUSTFLAGS to proc_macros:
130 // https://github.com/rust-lang/cargo/issues/4423
131 // Set `--cfg=bootstrap` explicitly instead.
132 cmd.arg("--cfg=bootstrap");
136 if let Ok(map) = env::var("RUSTC_DEBUGINFO_MAP") {
137 cmd.arg("--remap-path-prefix").arg(&map);
140 // Force all crates compiled by this compiler to (a) be unstable and (b)
141 // allow the `rustc_private` feature to link to other unstable crates
142 // also in the sysroot. We also do this for host crates, since those
143 // may be proc macros, in which case we might ship them.
144 if env::var_os("RUSTC_FORCE_UNSTABLE").is_some() && (stage != "0" || target.is_some()) {
145 cmd.arg("-Z").arg("force-unstable-if-unmarked");
148 let is_test = args.iter().any(|a| a == "--test");
151 env::vars().filter(|(k, _)| k.starts_with("RUST") || k.starts_with("CARGO"));
152 let prefix = if is_test { "[RUSTC-SHIM] rustc --test" } else { "[RUSTC-SHIM] rustc" };
153 let prefix = match crate_name {
154 Some(crate_name) => format!("{} {}", prefix, crate_name),
155 None => prefix.to_string(),
157 for (i, (k, v)) in rust_env_vars.enumerate() {
158 eprintln!("{} env[{}]: {:?}={:?}", prefix, i, k, v);
160 eprintln!("{} working directory: {}", prefix, env::current_dir().unwrap().display());
162 "{} command: {:?}={:?} {:?}",
164 bootstrap::util::dylib_path_var(),
165 env::join_paths(&dylib_path).unwrap(),
168 eprintln!("{} sysroot: {:?}", prefix, sysroot);
169 eprintln!("{} libdir: {:?}", prefix, libdir);
172 let start = Instant::now();
173 let (child, status) = {
174 let errmsg = format!("\nFailed to run:\n{:?}\n-------------", cmd);
175 let mut child = cmd.spawn().expect(&errmsg);
176 let status = child.wait().expect(&errmsg);
180 if env::var_os("RUSTC_PRINT_STEP_TIMINGS").is_some()
181 || env::var_os("RUSTC_PRINT_STEP_RUSAGE").is_some()
183 if let Some(crate_name) = crate_name {
184 let dur = start.elapsed();
185 // If the user requested resource usage data, then
186 // include that in addition to the timing output.
188 env::var_os("RUSTC_PRINT_STEP_RUSAGE").and_then(|_| format_rusage_data(child));
190 "[RUSTC-TIMING] {} test:{} {}.{:03}{}{}",
195 if rusage_data.is_some() { " " } else { "" },
196 rusage_data.unwrap_or(String::new()),
201 if status.success() {
202 std::process::exit(0);
203 // note: everything below here is unreachable. do not put code that
204 // should run on success, after this block.
207 println!("\nDid not run successfully: {}\n{:?}\n-------------", status, cmd);
210 if let Some(mut on_fail) = on_fail {
211 on_fail.status().expect("Could not run the on_fail command");
214 // Preserve the exit code. In case of signal, exit with 0xfe since it's
215 // awkward to preserve this status in a cross-platform way.
216 match status.code() {
217 Some(i) => std::process::exit(i),
219 eprintln!("rustc exited with {}", status);
220 std::process::exit(0xfe);
225 #[cfg(all(not(unix), not(windows)))]
226 // In the future we can add this for more platforms
227 fn format_rusage_data(_child: Child) -> Option<String> {
232 fn format_rusage_data(child: Child) -> Option<String> {
233 use std::os::windows::io::AsRawHandle;
234 use winapi::um::{processthreadsapi, psapi, timezoneapi};
235 let handle = child.as_raw_handle();
236 macro_rules! try_bool {
244 let mut user_filetime = Default::default();
245 let mut user_time = Default::default();
246 let mut kernel_filetime = Default::default();
247 let mut kernel_time = Default::default();
248 let mut memory_counters = psapi::PROCESS_MEMORY_COUNTERS::default();
251 try_bool!(processthreadsapi::GetProcessTimes(
253 &mut Default::default(),
254 &mut Default::default(),
255 &mut kernel_filetime,
258 try_bool!(timezoneapi::FileTimeToSystemTime(&user_filetime, &mut user_time));
259 try_bool!(timezoneapi::FileTimeToSystemTime(&kernel_filetime, &mut kernel_time));
261 // Unlike on Linux with RUSAGE_CHILDREN, this will only return memory information for the process
262 // with the given handle and none of that process's children.
263 try_bool!(psapi::GetProcessMemoryInfo(
265 &mut memory_counters as *mut _ as _,
266 std::mem::size_of::<psapi::PROCESS_MEMORY_COUNTERS_EX>() as u32,
270 // Guide on interpreting these numbers:
271 // https://docs.microsoft.com/en-us/windows/win32/psapi/process-memory-usage-information
272 let peak_working_set = memory_counters.PeakWorkingSetSize / 1024;
273 let peak_page_file = memory_counters.PeakPagefileUsage / 1024;
274 let peak_paged_pool = memory_counters.QuotaPeakPagedPoolUsage / 1024;
275 let peak_nonpaged_pool = memory_counters.QuotaPeakNonPagedPoolUsage / 1024;
277 "user: {USER_SEC}.{USER_USEC:03} \
278 sys: {SYS_SEC}.{SYS_USEC:03} \
279 peak working set (kb): {PEAK_WORKING_SET} \
280 peak page file usage (kb): {PEAK_PAGE_FILE} \
281 peak paged pool usage (kb): {PEAK_PAGED_POOL} \
282 peak non-paged pool usage (kb): {PEAK_NONPAGED_POOL} \
283 page faults: {PAGE_FAULTS}",
284 USER_SEC = user_time.wSecond + (user_time.wMinute * 60),
285 USER_USEC = user_time.wMilliseconds,
286 SYS_SEC = kernel_time.wSecond + (kernel_time.wMinute * 60),
287 SYS_USEC = kernel_time.wMilliseconds,
288 PEAK_WORKING_SET = peak_working_set,
289 PEAK_PAGE_FILE = peak_page_file,
290 PEAK_PAGED_POOL = peak_paged_pool,
291 PEAK_NONPAGED_POOL = peak_nonpaged_pool,
292 PAGE_FAULTS = memory_counters.PageFaultCount,
297 /// Tries to build a string with human readable data for several of the rusage
298 /// fields. Note that we are focusing mainly on data that we believe to be
299 /// supplied on Linux (the `rusage` struct has other fields in it but they are
300 /// currently unsupported by Linux).
301 fn format_rusage_data(_child: Child) -> Option<String> {
302 let rusage: libc::rusage = unsafe {
303 let mut recv = std::mem::zeroed();
304 // -1 is RUSAGE_CHILDREN, which means to get the rusage for all children
305 // (and grandchildren, etc) processes that have respectively terminated
306 // and been waited for.
307 let retval = libc::getrusage(-1, &mut recv);
313 // Mac OS X reports the maxrss in bytes, not kb.
314 let divisor = if env::consts::OS == "macos" { 1024 } else { 1 };
315 let maxrss = (rusage.ru_maxrss + (divisor - 1)) / divisor;
317 let mut init_str = format!(
318 "user: {USER_SEC}.{USER_USEC:03} \
319 sys: {SYS_SEC}.{SYS_USEC:03} \
320 max rss (kb): {MAXRSS}",
321 USER_SEC = rusage.ru_utime.tv_sec,
322 USER_USEC = rusage.ru_utime.tv_usec,
323 SYS_SEC = rusage.ru_stime.tv_sec,
324 SYS_USEC = rusage.ru_stime.tv_usec,
328 // The remaining rusage stats vary in platform support. So we treat
329 // uniformly zero values in each category as "not worth printing", since it
330 // either means no events of that type occurred, or that the platform
331 // does not support it.
333 let minflt = rusage.ru_minflt;
334 let majflt = rusage.ru_majflt;
335 if minflt != 0 || majflt != 0 {
336 init_str.push_str(&format!(" page reclaims: {} page faults: {}", minflt, majflt));
339 let inblock = rusage.ru_inblock;
340 let oublock = rusage.ru_oublock;
341 if inblock != 0 || oublock != 0 {
342 init_str.push_str(&format!(" fs block inputs: {} fs block outputs: {}", inblock, oublock));
345 let nvcsw = rusage.ru_nvcsw;
346 let nivcsw = rusage.ru_nivcsw;
347 if nvcsw != 0 || nivcsw != 0 {
348 init_str.push_str(&format!(
349 " voluntary ctxt switches: {} involuntary ctxt switches: {}",
354 return Some(init_str);