src/bootstrap/bin/rustc.rs

   1 //! Shim which is passed to Cargo as "rustc" when running the bootstrap.
   2 //!
   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:
   5 //!
   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.
  13 //!
  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.
  17
  18 include!("../dylib_util.rs");
  19
  20 use std::env;
  21 use std::path::PathBuf;
  22 use std::process::{Child, Command};
  23 use std::str::FromStr;
  24 use std::time::Instant;
  25
  26 fn main() {
  27     let args = env::args_os().skip(1).collect::<Vec<_>>();
  28
  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");
  33
  34     let verbose = match env::var("RUSTC_VERBOSE") {
  35         Ok(s) => usize::from_str(&s).expect("RUSTC_VERBOSE should be an integer"),
  36         Err(_) => 0,
  37     };
  38
  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")
  46     } else {
  47         ("RUSTC_REAL", "RUSTC_LIBDIR")
  48     };
  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);
  52
  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));
  57
  58     let mut cmd = Command::new(rustc);
  59     cmd.args(&args).env(dylib_path_var(), env::join_paths(&dylib_path).unwrap());
  60
  61     // Get the name of the crate we're compiling, if any.
  62     let crate_name =
  63         args.windows(2).find(|args| args[0] == "--crate-name").and_then(|args| args[1].to_str());
  64
  65     if let Some(crate_name) = crate_name {
  66         if let Some(target) = env::var_os("RUSTC_TIME") {
  67             if target == "all"
  68                 || target.into_string().unwrap().split(',').any(|c| c.trim() == crate_name)
  69             {
  70                 cmd.arg("-Ztime");
  71             }
  72         }
  73     }
  74
  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");
  78     }
  79
  80     if let Ok(lint_flags) = env::var("RUSTC_LINT_FLAGS") {
  81         cmd.args(lint_flags.split_whitespace());
  82     }
  83
  84     if target.is_some() {
  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);
  90         }
  91
  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.
  96         //
  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.
 100         //
 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"
 106         {
 107             cmd.arg("-C").arg("panic=abort");
 108         }
 109     } else {
 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.
 112
 113         // Override linker if necessary.
 114         if let Ok(host_linker) = env::var("RUSTC_HOST_LINKER") {
 115             cmd.arg(format!("-Clinker={}", host_linker));
 116         }
 117         if env::var_os("RUSTC_HOST_FUSE_LD_LLD").is_some() {
 118             cmd.arg("-Clink-args=-fuse-ld=lld");
 119         }
 120
 121         if let Ok(s) = env::var("RUSTC_HOST_CRT_STATIC") {
 122             if s == "true" {
 123                 cmd.arg("-C").arg("target-feature=+crt-static");
 124             }
 125             if s == "false" {
 126                 cmd.arg("-C").arg("target-feature=-crt-static");
 127             }
 128         }
 129
 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")].
 137         if stage == "0" {
 138             cmd.arg("--cfg=bootstrap");
 139         }
 140         cmd.arg("-Zunstable-options");
 141         cmd.arg("--check-cfg=values(bootstrap)");
 142     }
 143
 144     if let Ok(map) = env::var("RUSTC_DEBUGINFO_MAP") {
 145         cmd.arg("--remap-path-prefix").arg(&map);
 146     }
 147
 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");
 154     }
 155
 156     if let Ok(flags) = env::var("MAGIC_EXTRA_RUSTFLAGS") {
 157         for flag in flags.split(' ') {
 158             cmd.arg(flag);
 159         }
 160     }
 161
 162     let is_test = args.iter().any(|a| a == "--test");
 163     if verbose > 2 {
 164         let rust_env_vars =
 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(),
 170         };
 171         for (i, (k, v)) in rust_env_vars.enumerate() {
 172             eprintln!("{} env[{}]: {:?}={:?}", prefix, i, k, v);
 173         }
 174         eprintln!("{} working directory: {}", prefix, env::current_dir().unwrap().display());
 175         eprintln!(
 176             "{} command: {:?}={:?} {:?}",
 177             prefix,
 178             dylib_path_var(),
 179             env::join_paths(&dylib_path).unwrap(),
 180             cmd,
 181         );
 182         eprintln!("{} sysroot: {:?}", prefix, sysroot);
 183         eprintln!("{} libdir: {:?}", prefix, libdir);
 184     }
 185
 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);
 191         (child, status)
 192     };
 193
 194     if env::var_os("RUSTC_PRINT_STEP_TIMINGS").is_some()
 195         || env::var_os("RUSTC_PRINT_STEP_RUSAGE").is_some()
 196     {
 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.
 201             let rusage_data =
 202                 env::var_os("RUSTC_PRINT_STEP_RUSAGE").and_then(|_| format_rusage_data(child));
 203             eprintln!(
 204                 "[RUSTC-TIMING] {} test:{} {}.{:03}{}{}",
 205                 crate_name,
 206                 is_test,
 207                 dur.as_secs(),
 208                 dur.subsec_millis(),
 209                 if rusage_data.is_some() { " " } else { "" },
 210                 rusage_data.unwrap_or(String::new()),
 211             );
 212         }
 213     }
 214
 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.
 219     }
 220     if verbose > 0 {
 221         println!("\nDid not run successfully: {}\n{:?}\n-------------", status, cmd);
 222     }
 223
 224     if let Some(mut on_fail) = on_fail {
 225         on_fail.status().expect("Could not run the on_fail command");
 226     }
 227
 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),
 232         None => {
 233             eprintln!("rustc exited with {}", status);
 234             std::process::exit(0xfe);
 235         }
 236     }
 237 }
 238
 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> {
 242     None
 243 }
 244
 245 #[cfg(windows)]
 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 {
 251         ($e:expr) => {
 252             if $e != 1 {
 253                 return None;
 254             }
 255         };
 256     }
 257
 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();
 263
 264     unsafe {
 265         try_bool!(processthreadsapi::GetProcessTimes(
 266             handle,
 267             &mut Default::default(),
 268             &mut Default::default(),
 269             &mut kernel_filetime,
 270             &mut user_filetime,
 271         ));
 272         try_bool!(timezoneapi::FileTimeToSystemTime(&user_filetime, &mut user_time));
 273         try_bool!(timezoneapi::FileTimeToSystemTime(&kernel_filetime, &mut kernel_time));
 274
 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(
 278             handle as _,
 279             &mut memory_counters as *mut _ as _,
 280             std::mem::size_of::<psapi::PROCESS_MEMORY_COUNTERS_EX>() as u32,
 281         ));
 282     }
 283
 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;
 290     Some(format!(
 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,
 307     ))
 308 }
 309
 310 #[cfg(unix)]
 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);
 322         if retval != 0 {
 323             return None;
 324         }
 325         recv
 326     };
 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;
 330
 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,
 339         MAXRSS = maxrss
 340     );
 341
 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.
 346
 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));
 351     }
 352
 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));
 357     }
 358
 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: {}",
 364             nvcsw, nivcsw
 365         ));
 366     }
 367
 368     return Some(init_str);
 369 }