Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 1963 insertions, 0 deletions

diff --git a/compiler/rustc_driver/Cargo.toml b/compiler/rustc_driver/Cargo.toml
new file mode 100644
index 000000000..08d5d4f34
--- /dev/null
+++ b/compiler/rustc_driver/Cargo.toml
@@ -0,0 +1,44 @@
+[package]
+name = "rustc_driver"
+version = "0.0.0"
+edition = "2021"
+
+[lib]
+crate-type = ["dylib"]
+
+[dependencies]
+tracing = { version = "0.1.28" }
+serde_json = "1.0.59"
+rustc_log = { path = "../rustc_log" }
+rustc_middle = { path = "../rustc_middle" }
+rustc_ast_pretty = { path = "../rustc_ast_pretty" }
+rustc_target = { path = "../rustc_target" }
+rustc_lint = { path = "../rustc_lint" }
+rustc_data_structures = { path = "../rustc_data_structures" }
+rustc_errors = { path = "../rustc_errors" }
+rustc_feature = { path = "../rustc_feature" }
+rustc_hir = { path = "../rustc_hir" }
+rustc_hir_pretty = { path = "../rustc_hir_pretty" }
+rustc_metadata = { path = "../rustc_metadata" }
+rustc_parse = { path = "../rustc_parse" }
+rustc_plugin_impl = { path = "../rustc_plugin_impl" }
+rustc_save_analysis = { path = "../rustc_save_analysis" }
+rustc_codegen_ssa = { path = "../rustc_codegen_ssa" }
+rustc_session = { path = "../rustc_session" }
+rustc_error_codes = { path = "../rustc_error_codes" }
+rustc_interface = { path = "../rustc_interface" }
+rustc_ast = { path = "../rustc_ast" }
+rustc_span = { path = "../rustc_span" }
+rustc_typeck = { path = "../rustc_typeck" }
+
+[target.'cfg(unix)'.dependencies]
+libc = "0.2"
+
+[target.'cfg(windows)'.dependencies]
+winapi = { version = "0.3", features = ["consoleapi", "debugapi", "processenv"] }
+
+[features]
+llvm = ['rustc_interface/llvm']
+max_level_info = ['rustc_log/max_level_info']
+rustc_use_parallel_compiler = ['rustc_data_structures/rustc_use_parallel_compiler', 'rustc_interface/rustc_use_parallel_compiler',
+    'rustc_middle/rustc_use_parallel_compiler']
diff --git a/compiler/rustc_driver/README.md b/compiler/rustc_driver/README.md
new file mode 100644
index 000000000..37dc7f6ba
--- /dev/null
+++ b/compiler/rustc_driver/README.md
@@ -0,0 +1,10 @@
+The `driver` crate is effectively the "main" function for the rust
+compiler.  It orchestrates the compilation process and "knits together"
+the code from the other crates within rustc. This crate itself does
+not contain any of the "main logic" of the compiler (though it does
+have some code related to pretty printing or other minor compiler
+options).
+
+For more information about how the driver works, see the [rustc dev guide].
+
+[rustc dev guide]: https://rustc-dev-guide.rust-lang.org/rustc-driver.html
diff --git a/compiler/rustc_driver/src/args.rs b/compiler/rustc_driver/src/args.rs
new file mode 100644
index 000000000..01338359f
--- /dev/null
+++ b/compiler/rustc_driver/src/args.rs
@@ -0,0 +1,51 @@
+use std::error;
+use std::fmt;
+use std::fs;
+use std::io;
+
+fn arg_expand(arg: String) -> Result<Vec<String>, Error> {
+    if let Some(path) = arg.strip_prefix('@') {
+        let file = match fs::read_to_string(path) {
+            Ok(file) => file,
+            Err(ref err) if err.kind() == io::ErrorKind::InvalidData => {
+                return Err(Error::Utf8Error(Some(path.to_string())));
+            }
+            Err(err) => return Err(Error::IOError(path.to_string(), err)),
+        };
+        Ok(file.lines().map(ToString::to_string).collect())
+    } else {
+        Ok(vec![arg])
+    }
+}
+
+pub fn arg_expand_all(at_args: &[String]) -> Vec<String> {
+    let mut args = Vec::new();
+    for arg in at_args {
+        match arg_expand(arg.clone()) {
+            Ok(arg) => args.extend(arg),
+            Err(err) => rustc_session::early_error(
+                rustc_session::config::ErrorOutputType::default(),
+                &format!("Failed to load argument file: {}", err),
+            ),
+        }
+    }
+    args
+}
+
+#[derive(Debug)]
+pub enum Error {
+    Utf8Error(Option<String>),
+    IOError(String, io::Error),
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Error::Utf8Error(None) => write!(fmt, "Utf8 error"),
+            Error::Utf8Error(Some(path)) => write!(fmt, "Utf8 error in {}", path),
+            Error::IOError(path, err) => write!(fmt, "IO Error: {}: {}", path, err),
+        }
+    }
+}
+
+impl error::Error for Error {}
diff --git a/compiler/rustc_driver/src/lib.rs b/compiler/rustc_driver/src/lib.rs
new file mode 100644
index 000000000..53ae913f9
--- /dev/null
+++ b/compiler/rustc_driver/src/lib.rs
@@ -0,0 +1,1340 @@
+//! The Rust compiler.
+//!
+//! # Note
+//!
+//! This API is completely unstable and subject to change.
+
+#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![feature(let_else)]
+#![feature(once_cell)]
+#![recursion_limit = "256"]
+#![allow(rustc::potential_query_instability)]
+
+#[macro_use]
+extern crate tracing;
+
+pub extern crate rustc_plugin_impl as plugin;
+
+use rustc_ast as ast;
+use rustc_codegen_ssa::{traits::CodegenBackend, CodegenResults};
+use rustc_data_structures::profiling::{get_resident_set_size, print_time_passes_entry};
+use rustc_data_structures::sync::SeqCst;
+use rustc_errors::registry::{InvalidErrorCode, Registry};
+use rustc_errors::{ErrorGuaranteed, PResult};
+use rustc_feature::find_gated_cfg;
+use rustc_interface::util::{self, collect_crate_types, get_codegen_backend};
+use rustc_interface::{interface, Queries};
+use rustc_lint::LintStore;
+use rustc_log::stdout_isatty;
+use rustc_metadata::locator;
+use rustc_save_analysis as save;
+use rustc_save_analysis::DumpHandler;
+use rustc_session::config::{nightly_options, CG_OPTIONS, Z_OPTIONS};
+use rustc_session::config::{ErrorOutputType, Input, OutputType, PrintRequest, TrimmedDefPaths};
+use rustc_session::cstore::MetadataLoader;
+use rustc_session::getopts;
+use rustc_session::lint::{Lint, LintId};
+use rustc_session::{config, DiagnosticOutput, Session};
+use rustc_session::{early_error, early_error_no_abort, early_warn};
+use rustc_span::source_map::{FileLoader, FileName};
+use rustc_span::symbol::sym;
+use rustc_target::json::ToJson;
+
+use std::borrow::Cow;
+use std::cmp::max;
+use std::default::Default;
+use std::env;
+use std::ffi::OsString;
+use std::fs;
+use std::io::{self, Read, Write};
+use std::panic::{self, catch_unwind};
+use std::path::PathBuf;
+use std::process::{self, Command, Stdio};
+use std::str;
+use std::sync::LazyLock;
+use std::time::Instant;
+
+pub mod args;
+pub mod pretty;
+
+/// Exit status code used for successful compilation and help output.
+pub const EXIT_SUCCESS: i32 = 0;
+
+/// Exit status code used for compilation failures and invalid flags.
+pub const EXIT_FAILURE: i32 = 1;
+
+const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust/issues/new\
+    ?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md";
+
+const ICE_REPORT_COMPILER_FLAGS: &[&str] = &["-Z", "-C", "--crate-type"];
+
+const ICE_REPORT_COMPILER_FLAGS_EXCLUDE: &[&str] = &["metadata", "extra-filename"];
+
+const ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE: &[&str] = &["incremental"];
+
+pub fn abort_on_err<T>(result: Result<T, ErrorGuaranteed>, sess: &Session) -> T {
+    match result {
+        Err(..) => {
+            sess.abort_if_errors();
+            panic!("error reported but abort_if_errors didn't abort???");
+        }
+        Ok(x) => x,
+    }
+}
+
+pub trait Callbacks {
+    /// Called before creating the compiler instance
+    fn config(&mut self, _config: &mut interface::Config) {}
+    /// Called after parsing. Return value instructs the compiler whether to
+    /// continue the compilation afterwards (defaults to `Compilation::Continue`)
+    fn after_parsing<'tcx>(
+        &mut self,
+        _compiler: &interface::Compiler,
+        _queries: &'tcx Queries<'tcx>,
+    ) -> Compilation {
+        Compilation::Continue
+    }
+    /// Called after expansion. Return value instructs the compiler whether to
+    /// continue the compilation afterwards (defaults to `Compilation::Continue`)
+    fn after_expansion<'tcx>(
+        &mut self,
+        _compiler: &interface::Compiler,
+        _queries: &'tcx Queries<'tcx>,
+    ) -> Compilation {
+        Compilation::Continue
+    }
+    /// Called after analysis. Return value instructs the compiler whether to
+    /// continue the compilation afterwards (defaults to `Compilation::Continue`)
+    fn after_analysis<'tcx>(
+        &mut self,
+        _compiler: &interface::Compiler,
+        _queries: &'tcx Queries<'tcx>,
+    ) -> Compilation {
+        Compilation::Continue
+    }
+}
+
+#[derive(Default)]
+pub struct TimePassesCallbacks {
+    time_passes: bool,
+}
+
+impl Callbacks for TimePassesCallbacks {
+    fn config(&mut self, config: &mut interface::Config) {
+        // If a --prints=... option has been given, we don't print the "total"
+        // time because it will mess up the --prints output. See #64339.
+        self.time_passes = config.opts.prints.is_empty() && config.opts.time_passes();
+        config.opts.trimmed_def_paths = TrimmedDefPaths::GoodPath;
+    }
+}
+
+pub fn diagnostics_registry() -> Registry {
+    Registry::new(rustc_error_codes::DIAGNOSTICS)
+}
+
+/// This is the primary entry point for rustc.
+pub struct RunCompiler<'a, 'b> {
+    at_args: &'a [String],
+    callbacks: &'b mut (dyn Callbacks + Send),
+    file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
+    emitter: Option<Box<dyn Write + Send>>,
+    make_codegen_backend:
+        Option<Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>>,
+}
+
+impl<'a, 'b> RunCompiler<'a, 'b> {
+    pub fn new(at_args: &'a [String], callbacks: &'b mut (dyn Callbacks + Send)) -> Self {
+        Self { at_args, callbacks, file_loader: None, emitter: None, make_codegen_backend: None }
+    }
+
+    /// Set a custom codegen backend.
+    ///
+    /// Used by cg_clif.
+    pub fn set_make_codegen_backend(
+        &mut self,
+        make_codegen_backend: Option<
+            Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
+        >,
+    ) -> &mut Self {
+        self.make_codegen_backend = make_codegen_backend;
+        self
+    }
+
+    /// Emit diagnostics to the specified location.
+    ///
+    /// Used by RLS.
+    pub fn set_emitter(&mut self, emitter: Option<Box<dyn Write + Send>>) -> &mut Self {
+        self.emitter = emitter;
+        self
+    }
+
+    /// Load files from sources other than the file system.
+    ///
+    /// Used by RLS.
+    pub fn set_file_loader(
+        &mut self,
+        file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
+    ) -> &mut Self {
+        self.file_loader = file_loader;
+        self
+    }
+
+    /// Parse args and run the compiler.
+    pub fn run(self) -> interface::Result<()> {
+        run_compiler(
+            self.at_args,
+            self.callbacks,
+            self.file_loader,
+            self.emitter,
+            self.make_codegen_backend,
+        )
+    }
+}
+fn run_compiler(
+    at_args: &[String],
+    callbacks: &mut (dyn Callbacks + Send),
+    file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
+    emitter: Option<Box<dyn Write + Send>>,
+    make_codegen_backend: Option<
+        Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
+    >,
+) -> interface::Result<()> {
+    let args = args::arg_expand_all(at_args);
+
+    let diagnostic_output = emitter.map_or(DiagnosticOutput::Default, DiagnosticOutput::Raw);
+    let Some(matches) = handle_options(&args) else { return Ok(()) };
+
+    let sopts = config::build_session_options(&matches);
+
+    if let Some(ref code) = matches.opt_str("explain") {
+        handle_explain(diagnostics_registry(), code, sopts.error_format);
+        return Ok(());
+    }
+
+    let cfg = interface::parse_cfgspecs(matches.opt_strs("cfg"));
+    let check_cfg = interface::parse_check_cfg(matches.opt_strs("check-cfg"));
+    let (odir, ofile) = make_output(&matches);
+    let mut config = interface::Config {
+        opts: sopts,
+        crate_cfg: cfg,
+        crate_check_cfg: check_cfg,
+        input: Input::File(PathBuf::new()),
+        input_path: None,
+        output_file: ofile,
+        output_dir: odir,
+        file_loader,
+        diagnostic_output,
+        lint_caps: Default::default(),
+        parse_sess_created: None,
+        register_lints: None,
+        override_queries: None,
+        make_codegen_backend,
+        registry: diagnostics_registry(),
+    };
+
+    match make_input(config.opts.error_format, &matches.free) {
+        Err(reported) => return Err(reported),
+        Ok(Some((input, input_file_path))) => {
+            config.input = input;
+            config.input_path = input_file_path;
+
+            callbacks.config(&mut config);
+        }
+        Ok(None) => match matches.free.len() {
+            0 => {
+                callbacks.config(&mut config);
+                interface::run_compiler(config, |compiler| {
+                    let sopts = &compiler.session().opts;
+                    if sopts.describe_lints {
+                        let mut lint_store = rustc_lint::new_lint_store(
+                            sopts.unstable_opts.no_interleave_lints,
+                            compiler.session().enable_internal_lints(),
+                        );
+                        let registered_lints =
+                            if let Some(register_lints) = compiler.register_lints() {
+                                register_lints(compiler.session(), &mut lint_store);
+                                true
+                            } else {
+                                false
+                            };
+                        describe_lints(compiler.session(), &lint_store, registered_lints);
+                        return;
+                    }
+                    let should_stop = print_crate_info(
+                        &***compiler.codegen_backend(),
+                        compiler.session(),
+                        None,
+                        compiler.output_dir(),
+                        compiler.output_file(),
+                        compiler.temps_dir(),
+                    );
+
+                    if should_stop == Compilation::Stop {
+                        return;
+                    }
+                    early_error(sopts.error_format, "no input filename given")
+                });
+                return Ok(());
+            }
+            1 => panic!("make_input should have provided valid inputs"),
+            _ => early_error(
+                config.opts.error_format,
+                &format!(
+                    "multiple input filenames provided (first two filenames are `{}` and `{}`)",
+                    matches.free[0], matches.free[1],
+                ),
+            ),
+        },
+    };
+
+    interface::run_compiler(config, |compiler| {
+        let sess = compiler.session();
+        let should_stop = print_crate_info(
+            &***compiler.codegen_backend(),
+            sess,
+            Some(compiler.input()),
+            compiler.output_dir(),
+            compiler.output_file(),
+            compiler.temps_dir(),
+        )
+        .and_then(|| {
+            list_metadata(sess, &*compiler.codegen_backend().metadata_loader(), compiler.input())
+        })
+        .and_then(|| try_process_rlink(sess, compiler));
+
+        if should_stop == Compilation::Stop {
+            return sess.compile_status();
+        }
+
+        let linker = compiler.enter(|queries| {
+            let early_exit = || sess.compile_status().map(|_| None);
+            queries.parse()?;
+
+            if let Some(ppm) = &sess.opts.pretty {
+                if ppm.needs_ast_map() {
+                    let expanded_crate = queries.expansion()?.peek().0.clone();
+                    queries.global_ctxt()?.peek_mut().enter(|tcx| {
+                        pretty::print_after_hir_lowering(
+                            tcx,
+                            compiler.input(),
+                            &*expanded_crate,
+                            *ppm,
+                            compiler.output_file().as_ref().map(|p| &**p),
+                        );
+                        Ok(())
+                    })?;
+                } else {
+                    let krate = queries.parse()?.take();
+                    pretty::print_after_parsing(
+                        sess,
+                        compiler.input(),
+                        &krate,
+                        *ppm,
+                        compiler.output_file().as_ref().map(|p| &**p),
+                    );
+                }
+                trace!("finished pretty-printing");
+                return early_exit();
+            }
+
+            if callbacks.after_parsing(compiler, queries) == Compilation::Stop {
+                return early_exit();
+            }
+
+            if sess.opts.unstable_opts.parse_only || sess.opts.unstable_opts.show_span.is_some() {
+                return early_exit();
+            }
+
+            {
+                let (_, lint_store) = &*queries.register_plugins()?.peek();
+
+                // Lint plugins are registered; now we can process command line flags.
+                if sess.opts.describe_lints {
+                    describe_lints(sess, lint_store, true);
+                    return early_exit();
+                }
+            }
+
+            queries.expansion()?;
+            if callbacks.after_expansion(compiler, queries) == Compilation::Stop {
+                return early_exit();
+            }
+
+            queries.prepare_outputs()?;
+
+            if sess.opts.output_types.contains_key(&OutputType::DepInfo)
+                && sess.opts.output_types.len() == 1
+            {
+                return early_exit();
+            }
+
+            queries.global_ctxt()?;
+
+            if sess.opts.unstable_opts.no_analysis {
+                return early_exit();
+            }
+
+            queries.global_ctxt()?.peek_mut().enter(|tcx| {
+                let result = tcx.analysis(());
+                if sess.opts.unstable_opts.save_analysis {
+                    let crate_name = queries.crate_name()?.peek().clone();
+                    sess.time("save_analysis", || {
+                        save::process_crate(
+                            tcx,
+                            &crate_name,
+                            compiler.input(),
+                            None,
+                            DumpHandler::new(
+                                compiler.output_dir().as_ref().map(|p| &**p),
+                                &crate_name,
+                            ),
+                        )
+                    });
+                }
+                result
+            })?;
+
+            if callbacks.after_analysis(compiler, queries) == Compilation::Stop {
+                return early_exit();
+            }
+
+            queries.ongoing_codegen()?;
+
+            if sess.opts.unstable_opts.print_type_sizes {
+                sess.code_stats.print_type_sizes();
+            }
+
+            let linker = queries.linker()?;
+            Ok(Some(linker))
+        })?;
+
+        if let Some(linker) = linker {
+            let _timer = sess.timer("link");
+            linker.link()?
+        }
+
+        if sess.opts.unstable_opts.perf_stats {
+            sess.print_perf_stats();
+        }
+
+        if sess.opts.unstable_opts.print_fuel.is_some() {
+            eprintln!(
+                "Fuel used by {}: {}",
+                sess.opts.unstable_opts.print_fuel.as_ref().unwrap(),
+                sess.print_fuel.load(SeqCst)
+            );
+        }
+
+        Ok(())
+    })
+}
+
+#[cfg(unix)]
+pub fn set_sigpipe_handler() {
+    unsafe {
+        // Set the SIGPIPE signal handler, so that an EPIPE
+        // will cause rustc to terminate, as expected.
+        assert_ne!(libc::signal(libc::SIGPIPE, libc::SIG_DFL), libc::SIG_ERR);
+    }
+}
+
+#[cfg(windows)]
+pub fn set_sigpipe_handler() {}
+
+// Extract output directory and file from matches.
+fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
+    let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
+    let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
+    (odir, ofile)
+}
+
+// Extract input (string or file and optional path) from matches.
+fn make_input(
+    error_format: ErrorOutputType,
+    free_matches: &[String],
+) -> Result<Option<(Input, Option<PathBuf>)>, ErrorGuaranteed> {
+    if free_matches.len() == 1 {
+        let ifile = &free_matches[0];
+        if ifile == "-" {
+            let mut src = String::new();
+            if io::stdin().read_to_string(&mut src).is_err() {
+                // Immediately stop compilation if there was an issue reading
+                // the input (for example if the input stream is not UTF-8).
+                let reported = early_error_no_abort(
+                    error_format,
+                    "couldn't read from stdin, as it did not contain valid UTF-8",
+                );
+                return Err(reported);
+            }
+            if let Ok(path) = env::var("UNSTABLE_RUSTDOC_TEST_PATH") {
+                let line = env::var("UNSTABLE_RUSTDOC_TEST_LINE").expect(
+                    "when UNSTABLE_RUSTDOC_TEST_PATH is set \
+                                    UNSTABLE_RUSTDOC_TEST_LINE also needs to be set",
+                );
+                let line = isize::from_str_radix(&line, 10)
+                    .expect("UNSTABLE_RUSTDOC_TEST_LINE needs to be an number");
+                let file_name = FileName::doc_test_source_code(PathBuf::from(path), line);
+                Ok(Some((Input::Str { name: file_name, input: src }, None)))
+            } else {
+                Ok(Some((Input::Str { name: FileName::anon_source_code(&src), input: src }, None)))
+            }
+        } else {
+            Ok(Some((Input::File(PathBuf::from(ifile)), Some(PathBuf::from(ifile)))))
+        }
+    } else {
+        Ok(None)
+    }
+}
+
+/// Whether to stop or continue compilation.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum Compilation {
+    Stop,
+    Continue,
+}
+
+impl Compilation {
+    pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
+        match self {
+            Compilation::Stop => Compilation::Stop,
+            Compilation::Continue => next(),
+        }
+    }
+}
+
+fn handle_explain(registry: Registry, code: &str, output: ErrorOutputType) {
+    let upper_cased_code = code.to_ascii_uppercase();
+    let normalised = if upper_cased_code.starts_with('E') {
+        upper_cased_code
+    } else {
+        format!("E{0:0>4}", code)
+    };
+    match registry.try_find_description(&normalised) {
+        Ok(Some(description)) => {
+            let mut is_in_code_block = false;
+            let mut text = String::new();
+            // Slice off the leading newline and print.
+            for line in description.lines() {
+                let indent_level =
+                    line.find(|c: char| !c.is_whitespace()).unwrap_or_else(|| line.len());
+                let dedented_line = &line[indent_level..];
+                if dedented_line.starts_with("```") {
+                    is_in_code_block = !is_in_code_block;
+                    text.push_str(&line[..(indent_level + 3)]);
+                } else if is_in_code_block && dedented_line.starts_with("# ") {
+                    continue;
+                } else {
+                    text.push_str(line);
+                }
+                text.push('\n');
+            }
+            if stdout_isatty() {
+                show_content_with_pager(&text);
+            } else {
+                print!("{}", text);
+            }
+        }
+        Ok(None) => {
+            early_error(output, &format!("no extended information for {}", code));
+        }
+        Err(InvalidErrorCode) => {
+            early_error(output, &format!("{} is not a valid error code", code));
+        }
+    }
+}
+
+fn show_content_with_pager(content: &str) {
+    let pager_name = env::var_os("PAGER").unwrap_or_else(|| {
+        if cfg!(windows) { OsString::from("more.com") } else { OsString::from("less") }
+    });
+
+    let mut fallback_to_println = false;
+
+    match Command::new(pager_name).stdin(Stdio::piped()).spawn() {
+        Ok(mut pager) => {
+            if let Some(pipe) = pager.stdin.as_mut() {
+                if pipe.write_all(content.as_bytes()).is_err() {
+                    fallback_to_println = true;
+                }
+            }
+
+            if pager.wait().is_err() {
+                fallback_to_println = true;
+            }
+        }
+        Err(_) => {
+            fallback_to_println = true;
+        }
+    }
+
+    // If pager fails for whatever reason, we should still print the content
+    // to standard output
+    if fallback_to_println {
+        print!("{}", content);
+    }
+}
+
+pub fn try_process_rlink(sess: &Session, compiler: &interface::Compiler) -> Compilation {
+    if sess.opts.unstable_opts.link_only {
+        if let Input::File(file) = compiler.input() {
+            // FIXME: #![crate_type] and #![crate_name] support not implemented yet
+            sess.init_crate_types(collect_crate_types(sess, &[]));
+            let outputs = compiler.build_output_filenames(sess, &[]);
+            let rlink_data = fs::read(file).unwrap_or_else(|err| {
+                sess.fatal(&format!("failed to read rlink file: {}", err));
+            });
+            let codegen_results = match CodegenResults::deserialize_rlink(rlink_data) {
+                Ok(codegen) => codegen,
+                Err(error) => {
+                    sess.fatal(&format!("Could not deserialize .rlink file: {error}"));
+                }
+            };
+            let result = compiler.codegen_backend().link(sess, codegen_results, &outputs);
+            abort_on_err(result, sess);
+        } else {
+            sess.fatal("rlink must be a file")
+        }
+        Compilation::Stop
+    } else {
+        Compilation::Continue
+    }
+}
+
+pub fn list_metadata(
+    sess: &Session,
+    metadata_loader: &dyn MetadataLoader,
+    input: &Input,
+) -> Compilation {
+    if sess.opts.unstable_opts.ls {
+        match *input {
+            Input::File(ref ifile) => {
+                let path = &(*ifile);
+                let mut v = Vec::new();
+                locator::list_file_metadata(&sess.target, path, metadata_loader, &mut v).unwrap();
+                println!("{}", String::from_utf8(v).unwrap());
+            }
+            Input::Str { .. } => {
+                early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
+            }
+        }
+        return Compilation::Stop;
+    }
+
+    Compilation::Continue
+}
+
+fn print_crate_info(
+    codegen_backend: &dyn CodegenBackend,
+    sess: &Session,
+    input: Option<&Input>,
+    odir: &Option<PathBuf>,
+    ofile: &Option<PathBuf>,
+    temps_dir: &Option<PathBuf>,
+) -> Compilation {
+    use rustc_session::config::PrintRequest::*;
+    // NativeStaticLibs and LinkArgs are special - printed during linking
+    // (empty iterator returns true)
+    if sess.opts.prints.iter().all(|&p| p == NativeStaticLibs || p == LinkArgs) {
+        return Compilation::Continue;
+    }
+
+    let attrs = match input {
+        None => None,
+        Some(input) => {
+            let result = parse_crate_attrs(sess, input);
+            match result {
+                Ok(attrs) => Some(attrs),
+                Err(mut parse_error) => {
+                    parse_error.emit();
+                    return Compilation::Stop;
+                }
+            }
+        }
+    };
+    for req in &sess.opts.prints {
+        match *req {
+            TargetList => {
+                let mut targets = rustc_target::spec::TARGETS.iter().copied().collect::<Vec<_>>();
+                targets.sort_unstable();
+                println!("{}", targets.join("\n"));
+            }
+            Sysroot => println!("{}", sess.sysroot.display()),
+            TargetLibdir => println!("{}", sess.target_tlib_path.dir.display()),
+            TargetSpec => {
+                println!("{}", serde_json::to_string_pretty(&sess.target.to_json()).unwrap());
+            }
+            FileNames | CrateName => {
+                let input = input.unwrap_or_else(|| {
+                    early_error(ErrorOutputType::default(), "no input file provided")
+                });
+                let attrs = attrs.as_ref().unwrap();
+                let t_outputs = rustc_interface::util::build_output_filenames(
+                    input, odir, ofile, temps_dir, attrs, sess,
+                );
+                let id = rustc_session::output::find_crate_name(sess, attrs, input);
+                if *req == PrintRequest::CrateName {
+                    println!("{}", id);
+                    continue;
+                }
+                let crate_types = collect_crate_types(sess, attrs);
+                for &style in &crate_types {
+                    let fname =
+                        rustc_session::output::filename_for_input(sess, style, &id, &t_outputs);
+                    println!("{}", fname.file_name().unwrap().to_string_lossy());
+                }
+            }
+            Cfg => {
+                let mut cfgs = sess
+                    .parse_sess
+                    .config
+                    .iter()
+                    .filter_map(|&(name, value)| {
+                        // Note that crt-static is a specially recognized cfg
+                        // directive that's printed out here as part of
+                        // rust-lang/rust#37406, but in general the
+                        // `target_feature` cfg is gated under
+                        // rust-lang/rust#29717. For now this is just
+                        // specifically allowing the crt-static cfg and that's
+                        // it, this is intended to get into Cargo and then go
+                        // through to build scripts.
+                        if (name != sym::target_feature || value != Some(sym::crt_dash_static))
+                            && !sess.is_nightly_build()
+                            && find_gated_cfg(|cfg_sym| cfg_sym == name).is_some()
+                        {
+                            return None;
+                        }
+
+                        if let Some(value) = value {
+                            Some(format!("{}=\"{}\"", name, value))
+                        } else {
+                            Some(name.to_string())
+                        }
+                    })
+                    .collect::<Vec<String>>();
+
+                cfgs.sort();
+                for cfg in cfgs {
+                    println!("{}", cfg);
+                }
+            }
+            RelocationModels
+            | CodeModels
+            | TlsModels
+            | TargetCPUs
+            | StackProtectorStrategies
+            | TargetFeatures => {
+                codegen_backend.print(*req, sess);
+            }
+            // Any output here interferes with Cargo's parsing of other printed output
+            NativeStaticLibs => {}
+            LinkArgs => {}
+        }
+    }
+    Compilation::Stop
+}
+
+/// Prints version information
+pub fn version(binary: &str, matches: &getopts::Matches) {
+    let verbose = matches.opt_present("verbose");
+
+    println!("{} {}", binary, util::version_str().unwrap_or("unknown version"));
+
+    if verbose {
+        fn unw(x: Option<&str>) -> &str {
+            x.unwrap_or("unknown")
+        }
+        println!("binary: {}", binary);
+        println!("commit-hash: {}", unw(util::commit_hash_str()));
+        println!("commit-date: {}", unw(util::commit_date_str()));
+        println!("host: {}", config::host_triple());
+        println!("release: {}", unw(util::release_str()));
+
+        let debug_flags = matches.opt_strs("Z");
+        let backend_name = debug_flags.iter().find_map(|x| x.strip_prefix("codegen-backend="));
+        get_codegen_backend(&None, backend_name).print_version();
+    }
+}
+
+fn usage(verbose: bool, include_unstable_options: bool, nightly_build: bool) {
+    let groups = if verbose { config::rustc_optgroups() } else { config::rustc_short_optgroups() };
+    let mut options = getopts::Options::new();
+    for option in groups.iter().filter(|x| include_unstable_options || x.is_stable()) {
+        (option.apply)(&mut options);
+    }
+    let message = "Usage: rustc [OPTIONS] INPUT";
+    let nightly_help = if nightly_build {
+        "\n    -Z help             Print unstable compiler options"
+    } else {
+        ""
+    };
+    let verbose_help = if verbose {
+        ""
+    } else {
+        "\n    --help -v           Print the full set of options rustc accepts"
+    };
+    let at_path = if verbose {
+        "    @path               Read newline separated options from `path`\n"
+    } else {
+        ""
+    };
+    println!(
+        "{options}{at_path}\nAdditional help:
+    -C help             Print codegen options
+    -W help             \
+              Print 'lint' options and default settings{nightly}{verbose}\n",
+        options = options.usage(message),
+        at_path = at_path,
+        nightly = nightly_help,
+        verbose = verbose_help
+    );
+}
+
+fn print_wall_help() {
+    println!(
+        "
+The flag `-Wall` does not exist in `rustc`. Most useful lints are enabled by
+default. Use `rustc -W help` to see all available lints. It's more common to put
+warning settings in the crate root using `#![warn(LINT_NAME)]` instead of using
+the command line flag directly.
+"
+    );
+}
+
+/// Write to stdout lint command options, together with a list of all available lints
+pub fn describe_lints(sess: &Session, lint_store: &LintStore, loaded_plugins: bool) {
+    println!(
+        "
+Available lint options:
+    -W <foo>           Warn about <foo>
+    -A <foo>           \
+              Allow <foo>
+    -D <foo>           Deny <foo>
+    -F <foo>           Forbid <foo> \
+              (deny <foo> and all attempts to override)
+
+"
+    );
+
+    fn sort_lints(sess: &Session, mut lints: Vec<&'static Lint>) -> Vec<&'static Lint> {
+        // The sort doesn't case-fold but it's doubtful we care.
+        lints.sort_by_cached_key(|x: &&Lint| (x.default_level(sess.edition()), x.name));
+        lints
+    }
+
+    fn sort_lint_groups(
+        lints: Vec<(&'static str, Vec<LintId>, bool)>,
+    ) -> Vec<(&'static str, Vec<LintId>)> {
+        let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
+        lints.sort_by_key(|l| l.0);
+        lints
+    }
+
+    let (plugin, builtin): (Vec<_>, _) =
+        lint_store.get_lints().iter().cloned().partition(|&lint| lint.is_plugin);
+    let plugin = sort_lints(sess, plugin);
+    let builtin = sort_lints(sess, builtin);
+
+    let (plugin_groups, builtin_groups): (Vec<_>, _) =
+        lint_store.get_lint_groups().partition(|&(.., p)| p);
+    let plugin_groups = sort_lint_groups(plugin_groups);
+    let builtin_groups = sort_lint_groups(builtin_groups);
+
+    let max_name_len =
+        plugin.iter().chain(&builtin).map(|&s| s.name.chars().count()).max().unwrap_or(0);
+    let padded = |x: &str| {
+        let mut s = " ".repeat(max_name_len - x.chars().count());
+        s.push_str(x);
+        s
+    };
+
+    println!("Lint checks provided by rustc:\n");
+
+    let print_lints = |lints: Vec<&Lint>| {
+        println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
+        println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
+        for lint in lints {
+            let name = lint.name_lower().replace('_', "-");
+            println!(
+                "    {}  {:7.7}  {}",
+                padded(&name),
+                lint.default_level(sess.edition()).as_str(),
+                lint.desc
+            );
+        }
+        println!("\n");
+    };
+
+    print_lints(builtin);
+
+    let max_name_len = max(
+        "warnings".len(),
+        plugin_groups
+            .iter()
+            .chain(&builtin_groups)
+            .map(|&(s, _)| s.chars().count())
+            .max()
+            .unwrap_or(0),
+    );
+
+    let padded = |x: &str| {
+        let mut s = " ".repeat(max_name_len - x.chars().count());
+        s.push_str(x);
+        s
+    };
+
+    println!("Lint groups provided by rustc:\n");
+
+    let print_lint_groups = |lints: Vec<(&'static str, Vec<LintId>)>, all_warnings| {
+        println!("    {}  sub-lints", padded("name"));
+        println!("    {}  ---------", padded("----"));
+
+        if all_warnings {
+            println!("    {}  all lints that are set to issue warnings", padded("warnings"));
+        }
+
+        for (name, to) in lints {
+            let name = name.to_lowercase().replace('_', "-");
+            let desc = to
+                .into_iter()
+                .map(|x| x.to_string().replace('_', "-"))
+                .collect::<Vec<String>>()
+                .join(", ");
+            println!("    {}  {}", padded(&name), desc);
+        }
+        println!("\n");
+    };
+
+    print_lint_groups(builtin_groups, true);
+
+    match (loaded_plugins, plugin.len(), plugin_groups.len()) {
+        (false, 0, _) | (false, _, 0) => {
+            println!("Lint tools like Clippy can provide additional lints and lint groups.");
+        }
+        (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
+        (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
+        (true, l, g) => {
+            if l > 0 {
+                println!("Lint checks provided by plugins loaded by this crate:\n");
+                print_lints(plugin);
+            }
+            if g > 0 {
+                println!("Lint groups provided by plugins loaded by this crate:\n");
+                print_lint_groups(plugin_groups, false);
+            }
+        }
+    }
+}
+
+fn describe_debug_flags() {
+    println!("\nAvailable options:\n");
+    print_flag_list("-Z", config::Z_OPTIONS);
+}
+
+fn describe_codegen_flags() {
+    println!("\nAvailable codegen options:\n");
+    print_flag_list("-C", config::CG_OPTIONS);
+}
+
+pub fn print_flag_list<T>(
+    cmdline_opt: &str,
+    flag_list: &[(&'static str, T, &'static str, &'static str)],
+) {
+    let max_len = flag_list.iter().map(|&(name, _, _, _)| name.chars().count()).max().unwrap_or(0);
+
+    for &(name, _, _, desc) in flag_list {
+        println!(
+            "    {} {:>width$}=val -- {}",
+            cmdline_opt,
+            name.replace('_', "-"),
+            desc,
+            width = max_len
+        );
+    }
+}
+
+/// Process command line options. Emits messages as appropriate. If compilation
+/// should continue, returns a getopts::Matches object parsed from args,
+/// otherwise returns `None`.
+///
+/// The compiler's handling of options is a little complicated as it ties into
+/// our stability story. The current intention of each compiler option is to
+/// have one of two modes:
+///
+/// 1. An option is stable and can be used everywhere.
+/// 2. An option is unstable, and can only be used on nightly.
+///
+/// Like unstable library and language features, however, unstable options have
+/// always required a form of "opt in" to indicate that you're using them. This
+/// provides the easy ability to scan a code base to check to see if anything
+/// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
+///
+/// All options behind `-Z` are considered unstable by default. Other top-level
+/// options can also be considered unstable, and they were unlocked through the
+/// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
+/// instability in both cases, though.
+///
+/// So with all that in mind, the comments below have some more detail about the
+/// contortions done here to get things to work out correctly.
+pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
+    // Throw away the first argument, the name of the binary
+    let args = &args[1..];
+
+    if args.is_empty() {
+        // user did not write `-v` nor `-Z unstable-options`, so do not
+        // include that extra information.
+        let nightly_build =
+            rustc_feature::UnstableFeatures::from_environment(None).is_nightly_build();
+        usage(false, false, nightly_build);
+        return None;
+    }
+
+    // Parse with *all* options defined in the compiler, we don't worry about
+    // option stability here we just want to parse as much as possible.
+    let mut options = getopts::Options::new();
+    for option in config::rustc_optgroups() {
+        (option.apply)(&mut options);
+    }
+    let matches = options.parse(args).unwrap_or_else(|e| {
+        let msg = match e {
+            getopts::Fail::UnrecognizedOption(ref opt) => CG_OPTIONS
+                .iter()
+                .map(|&(name, ..)| ('C', name))
+                .chain(Z_OPTIONS.iter().map(|&(name, ..)| ('Z', name)))
+                .find(|&(_, name)| *opt == name.replace('_', "-"))
+                .map(|(flag, _)| format!("{}. Did you mean `-{} {}`?", e, flag, opt)),
+            _ => None,
+        };
+        early_error(ErrorOutputType::default(), &msg.unwrap_or_else(|| e.to_string()));
+    });
+
+    // For all options we just parsed, we check a few aspects:
+    //
+    // * If the option is stable, we're all good
+    // * If the option wasn't passed, we're all good
+    // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
+    //   ourselves), then we require the `-Z unstable-options` flag to unlock
+    //   this option that was passed.
+    // * If we're a nightly compiler, then unstable options are now unlocked, so
+    //   we're good to go.
+    // * Otherwise, if we're an unstable option then we generate an error
+    //   (unstable option being used on stable)
+    nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
+
+    if matches.opt_present("h") || matches.opt_present("help") {
+        // Only show unstable options in --help if we accept unstable options.
+        let unstable_enabled = nightly_options::is_unstable_enabled(&matches);
+        let nightly_build = nightly_options::match_is_nightly_build(&matches);
+        usage(matches.opt_present("verbose"), unstable_enabled, nightly_build);
+        return None;
+    }
+
+    // Handle the special case of -Wall.
+    let wall = matches.opt_strs("W");
+    if wall.iter().any(|x| *x == "all") {
+        print_wall_help();
+        rustc_errors::FatalError.raise();
+    }
+
+    // Don't handle -W help here, because we might first load plugins.
+    let debug_flags = matches.opt_strs("Z");
+    if debug_flags.iter().any(|x| *x == "help") {
+        describe_debug_flags();
+        return None;
+    }
+
+    let cg_flags = matches.opt_strs("C");
+
+    if cg_flags.iter().any(|x| *x == "help") {
+        describe_codegen_flags();
+        return None;
+    }
+
+    if cg_flags.iter().any(|x| *x == "no-stack-check") {
+        early_warn(
+            ErrorOutputType::default(),
+            "the --no-stack-check flag is deprecated and does nothing",
+        );
+    }
+
+    if cg_flags.iter().any(|x| *x == "passes=list") {
+        let backend_name = debug_flags.iter().find_map(|x| x.strip_prefix("codegen-backend="));
+        get_codegen_backend(&None, backend_name).print_passes();
+        return None;
+    }
+
+    if matches.opt_present("version") {
+        version("rustc", &matches);
+        return None;
+    }
+
+    Some(matches)
+}
+
+fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
+    match input {
+        Input::File(ifile) => rustc_parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess),
+        Input::Str { name, input } => rustc_parse::parse_crate_attrs_from_source_str(
+            name.clone(),
+            input.clone(),
+            &sess.parse_sess,
+        ),
+    }
+}
+
+/// Gets a list of extra command-line flags provided by the user, as strings.
+///
+/// This function is used during ICEs to show more information useful for
+/// debugging, since some ICEs only happens with non-default compiler flags
+/// (and the users don't always report them).
+fn extra_compiler_flags() -> Option<(Vec<String>, bool)> {
+    let mut args = env::args_os().map(|arg| arg.to_string_lossy().to_string()).peekable();
+
+    let mut result = Vec::new();
+    let mut excluded_cargo_defaults = false;
+    while let Some(arg) = args.next() {
+        if let Some(a) = ICE_REPORT_COMPILER_FLAGS.iter().find(|a| arg.starts_with(*a)) {
+            let content = if arg.len() == a.len() {
+                match args.next() {
+                    Some(arg) => arg.to_string(),
+                    None => continue,
+                }
+            } else if arg.get(a.len()..a.len() + 1) == Some("=") {
+                arg[a.len() + 1..].to_string()
+            } else {
+                arg[a.len()..].to_string()
+            };
+            if ICE_REPORT_COMPILER_FLAGS_EXCLUDE.iter().any(|exc| content.starts_with(exc)) {
+                excluded_cargo_defaults = true;
+            } else {
+                result.push(a.to_string());
+                match ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.iter().find(|s| content.starts_with(*s))
+                {
+                    Some(s) => result.push(s.to_string()),
+                    None => result.push(content),
+                }
+            }
+        }
+    }
+
+    if !result.is_empty() { Some((result, excluded_cargo_defaults)) } else { None }
+}
+
+/// Runs a closure and catches unwinds triggered by fatal errors.
+///
+/// The compiler currently unwinds with a special sentinel value to abort
+/// compilation on fatal errors. This function catches that sentinel and turns
+/// the panic into a `Result` instead.
+pub fn catch_fatal_errors<F: FnOnce() -> R, R>(f: F) -> Result<R, ErrorGuaranteed> {
+    catch_unwind(panic::AssertUnwindSafe(f)).map_err(|value| {
+        if value.is::<rustc_errors::FatalErrorMarker>() {
+            ErrorGuaranteed::unchecked_claim_error_was_emitted()
+        } else {
+            panic::resume_unwind(value);
+        }
+    })
+}
+
+/// Variant of `catch_fatal_errors` for the `interface::Result` return type
+/// that also computes the exit code.
+pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 {
+    let result = catch_fatal_errors(f).and_then(|result| result);
+    match result {
+        Ok(()) => EXIT_SUCCESS,
+        Err(_) => EXIT_FAILURE,
+    }
+}
+
+static DEFAULT_HOOK: LazyLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> =
+    LazyLock::new(|| {
+        let hook = panic::take_hook();
+        panic::set_hook(Box::new(|info| {
+            // Invoke the default handler, which prints the actual panic message and optionally a backtrace
+            (*DEFAULT_HOOK)(info);
+
+            // Separate the output with an empty line
+            eprintln!();
+
+            // Print the ICE message
+            report_ice(info, BUG_REPORT_URL);
+        }));
+        hook
+    });
+
+/// Prints the ICE message, including query stack, but without backtrace.
+///
+/// The message will point the user at `bug_report_url` to report the ICE.
+///
+/// When `install_ice_hook` is called, this function will be called as the panic
+/// hook.
+pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
+    let fallback_bundle =
+        rustc_errors::fallback_fluent_bundle(rustc_errors::DEFAULT_LOCALE_RESOURCES, false);
+    let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr(
+        rustc_errors::ColorConfig::Auto,
+        None,
+        None,
+        fallback_bundle,
+        false,
+        false,
+        None,
+        false,
+    ));
+    let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
+
+    // a .span_bug or .bug call has already printed what
+    // it wants to print.
+    if !info.payload().is::<rustc_errors::ExplicitBug>() {
+        let mut d = rustc_errors::Diagnostic::new(rustc_errors::Level::Bug, "unexpected panic");
+        handler.emit_diagnostic(&mut d);
+    }
+
+    let mut xs: Vec<Cow<'static, str>> = vec![
+        "the compiler unexpectedly panicked. this is a bug.".into(),
+        format!("we would appreciate a bug report: {}", bug_report_url).into(),
+        format!(
+            "rustc {} running on {}",
+            util::version_str().unwrap_or("unknown_version"),
+            config::host_triple()
+        )
+        .into(),
+    ];
+
+    if let Some((flags, excluded_cargo_defaults)) = extra_compiler_flags() {
+        xs.push(format!("compiler flags: {}", flags.join(" ")).into());
+
+        if excluded_cargo_defaults {
+            xs.push("some of the compiler flags provided by cargo are hidden".into());
+        }
+    }
+
+    for note in &xs {
+        handler.note_without_error(note.as_ref());
+    }
+
+    // If backtraces are enabled, also print the query stack
+    let backtrace = env::var_os("RUST_BACKTRACE").map_or(false, |x| &x != "0");
+
+    let num_frames = if backtrace { None } else { Some(2) };
+
+    interface::try_print_query_stack(&handler, num_frames);
+
+    #[cfg(windows)]
+    unsafe {
+        if env::var("RUSTC_BREAK_ON_ICE").is_ok() {
+            // Trigger a debugger if we crashed during bootstrap
+            winapi::um::debugapi::DebugBreak();
+        }
+    }
+}
+
+/// Installs a panic hook that will print the ICE message on unexpected panics.
+///
+/// A custom rustc driver can skip calling this to set up a custom ICE hook.
+pub fn install_ice_hook() {
+    // If the user has not explicitly overridden "RUST_BACKTRACE", then produce
+    // full backtraces. When a compiler ICE happens, we want to gather
+    // as much information as possible to present in the issue opened
+    // by the user. Compiler developers and other rustc users can
+    // opt in to less-verbose backtraces by manually setting "RUST_BACKTRACE"
+    // (e.g. `RUST_BACKTRACE=1`)
+    if std::env::var("RUST_BACKTRACE").is_err() {
+        std::env::set_var("RUST_BACKTRACE", "full");
+    }
+    LazyLock::force(&DEFAULT_HOOK);
+}
+
+/// This allows tools to enable rust logging without having to magically match rustc's
+/// tracing crate version.
+pub fn init_rustc_env_logger() {
+    if let Err(error) = rustc_log::init_rustc_env_logger() {
+        early_error(ErrorOutputType::default(), &error.to_string());
+    }
+}
+
+/// This allows tools to enable rust logging without having to magically match rustc's
+/// tracing crate version. In contrast to `init_rustc_env_logger` it allows you to choose an env var
+/// other than `RUSTC_LOG`.
+pub fn init_env_logger(env: &str) {
+    if let Err(error) = rustc_log::init_env_logger(env) {
+        early_error(ErrorOutputType::default(), &error.to_string());
+    }
+}
+
+#[cfg(all(unix, any(target_env = "gnu", target_os = "macos")))]
+mod signal_handler {
+    extern "C" {
+        fn backtrace_symbols_fd(
+            buffer: *const *mut libc::c_void,
+            size: libc::c_int,
+            fd: libc::c_int,
+        );
+    }
+
+    extern "C" fn print_stack_trace(_: libc::c_int) {
+        const MAX_FRAMES: usize = 256;
+        static mut STACK_TRACE: [*mut libc::c_void; MAX_FRAMES] =
+            [std::ptr::null_mut(); MAX_FRAMES];
+        unsafe {
+            let depth = libc::backtrace(STACK_TRACE.as_mut_ptr(), MAX_FRAMES as i32);
+            if depth == 0 {
+                return;
+            }
+            backtrace_symbols_fd(STACK_TRACE.as_ptr(), depth, 2);
+        }
+    }
+
+    // When an error signal (such as SIGABRT or SIGSEGV) is delivered to the
+    // process, print a stack trace and then exit.
+    pub(super) fn install() {
+        unsafe {
+            const ALT_STACK_SIZE: usize = libc::MINSIGSTKSZ + 64 * 1024;
+            let mut alt_stack: libc::stack_t = std::mem::zeroed();
+            alt_stack.ss_sp =
+                std::alloc::alloc(std::alloc::Layout::from_size_align(ALT_STACK_SIZE, 1).unwrap())
+                    as *mut libc::c_void;
+            alt_stack.ss_size = ALT_STACK_SIZE;
+            libc::sigaltstack(&alt_stack, std::ptr::null_mut());
+
+            let mut sa: libc::sigaction = std::mem::zeroed();
+            sa.sa_sigaction = print_stack_trace as libc::sighandler_t;
+            sa.sa_flags = libc::SA_NODEFER | libc::SA_RESETHAND | libc::SA_ONSTACK;
+            libc::sigemptyset(&mut sa.sa_mask);
+            libc::sigaction(libc::SIGSEGV, &sa, std::ptr::null_mut());
+        }
+    }
+}
+
+#[cfg(not(all(unix, any(target_env = "gnu", target_os = "macos"))))]
+mod signal_handler {
+    pub(super) fn install() {}
+}
+
+pub fn main() -> ! {
+    let start_time = Instant::now();
+    let start_rss = get_resident_set_size();
+    init_rustc_env_logger();
+    signal_handler::install();
+    let mut callbacks = TimePassesCallbacks::default();
+    install_ice_hook();
+    let exit_code = catch_with_exit_code(|| {
+        let args = env::args_os()
+            .enumerate()
+            .map(|(i, arg)| {
+                arg.into_string().unwrap_or_else(|arg| {
+                    early_error(
+                        ErrorOutputType::default(),
+                        &format!("argument {} is not valid Unicode: {:?}", i, arg),
+                    )
+                })
+            })
+            .collect::<Vec<_>>();
+        RunCompiler::new(&args, &mut callbacks).run()
+    });
+
+    if callbacks.time_passes {
+        let end_rss = get_resident_set_size();
+        print_time_passes_entry("total", start_time.elapsed(), start_rss, end_rss);
+    }
+
+    process::exit(exit_code)
+}
diff --git a/compiler/rustc_driver/src/pretty.rs b/compiler/rustc_driver/src/pretty.rs
new file mode 100644
index 000000000..f66b1a297
--- /dev/null
+++ b/compiler/rustc_driver/src/pretty.rs
@@ -0,0 +1,518 @@
+//! The various pretty-printing routines.
+
+use rustc_ast as ast;
+use rustc_ast_pretty::pprust;
+use rustc_errors::ErrorGuaranteed;
+use rustc_hir as hir;
+use rustc_hir_pretty as pprust_hir;
+use rustc_middle::hir::map as hir_map;
+use rustc_middle::mir::{write_mir_graphviz, write_mir_pretty};
+use rustc_middle::ty::{self, TyCtxt};
+use rustc_session::config::{Input, PpAstTreeMode, PpHirMode, PpMode, PpSourceMode};
+use rustc_session::Session;
+use rustc_span::symbol::Ident;
+use rustc_span::FileName;
+
+use std::cell::Cell;
+use std::fmt::Write;
+use std::path::Path;
+
+pub use self::PpMode::*;
+pub use self::PpSourceMode::*;
+use crate::abort_on_err;
+
+// This slightly awkward construction is to allow for each PpMode to
+// choose whether it needs to do analyses (which can consume the
+// Session) and then pass through the session (now attached to the
+// analysis results) on to the chosen pretty-printer, along with the
+// `&PpAnn` object.
+//
+// Note that since the `&PrinterSupport` is freshly constructed on each
+// call, it would not make sense to try to attach the lifetime of `self`
+// to the lifetime of the `&PrinterObject`.
+
+/// Constructs a `PrinterSupport` object and passes it to `f`.
+fn call_with_pp_support<'tcx, A, F>(
+    ppmode: &PpSourceMode,
+    sess: &'tcx Session,
+    tcx: Option<TyCtxt<'tcx>>,
+    f: F,
+) -> A
+where
+    F: FnOnce(&dyn PrinterSupport) -> A,
+{
+    match *ppmode {
+        Normal | Expanded => {
+            let annotation = NoAnn { sess, tcx };
+            f(&annotation)
+        }
+
+        Identified | ExpandedIdentified => {
+            let annotation = IdentifiedAnnotation { sess, tcx };
+            f(&annotation)
+        }
+        ExpandedHygiene => {
+            let annotation = HygieneAnnotation { sess };
+            f(&annotation)
+        }
+    }
+}
+fn call_with_pp_support_hir<A, F>(ppmode: &PpHirMode, tcx: TyCtxt<'_>, f: F) -> A
+where
+    F: FnOnce(&dyn HirPrinterSupport<'_>, hir_map::Map<'_>) -> A,
+{
+    match *ppmode {
+        PpHirMode::Normal => {
+            let annotation = NoAnn { sess: tcx.sess, tcx: Some(tcx) };
+            f(&annotation, tcx.hir())
+        }
+
+        PpHirMode::Identified => {
+            let annotation = IdentifiedAnnotation { sess: tcx.sess, tcx: Some(tcx) };
+            f(&annotation, tcx.hir())
+        }
+        PpHirMode::Typed => {
+            abort_on_err(tcx.analysis(()), tcx.sess);
+
+            let annotation = TypedAnnotation { tcx, maybe_typeck_results: Cell::new(None) };
+            tcx.dep_graph.with_ignore(|| f(&annotation, tcx.hir()))
+        }
+    }
+}
+
+trait PrinterSupport: pprust::PpAnn {
+    /// Provides a uniform interface for re-extracting a reference to a
+    /// `Session` from a value that now owns it.
+    fn sess(&self) -> &Session;
+
+    /// Produces the pretty-print annotation object.
+    ///
+    /// (Rust does not yet support upcasting from a trait object to
+    /// an object for one of its supertraits.)
+    fn pp_ann(&self) -> &dyn pprust::PpAnn;
+}
+
+trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
+    /// Provides a uniform interface for re-extracting a reference to a
+    /// `Session` from a value that now owns it.
+    fn sess(&self) -> &Session;
+
+    /// Provides a uniform interface for re-extracting a reference to an
+    /// `hir_map::Map` from a value that now owns it.
+    fn hir_map(&self) -> Option<hir_map::Map<'hir>>;
+
+    /// Produces the pretty-print annotation object.
+    ///
+    /// (Rust does not yet support upcasting from a trait object to
+    /// an object for one of its supertraits.)
+    fn pp_ann(&self) -> &dyn pprust_hir::PpAnn;
+}
+
+struct NoAnn<'hir> {
+    sess: &'hir Session,
+    tcx: Option<TyCtxt<'hir>>,
+}
+
+impl<'hir> PrinterSupport for NoAnn<'hir> {
+    fn sess(&self) -> &Session {
+        self.sess
+    }
+
+    fn pp_ann(&self) -> &dyn pprust::PpAnn {
+        self
+    }
+}
+
+impl<'hir> HirPrinterSupport<'hir> for NoAnn<'hir> {
+    fn sess(&self) -> &Session {
+        self.sess
+    }
+
+    fn hir_map(&self) -> Option<hir_map::Map<'hir>> {
+        self.tcx.map(|tcx| tcx.hir())
+    }
+
+    fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
+        self
+    }
+}
+
+impl<'hir> pprust::PpAnn for NoAnn<'hir> {}
+impl<'hir> pprust_hir::PpAnn for NoAnn<'hir> {
+    fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
+        if let Some(tcx) = self.tcx {
+            pprust_hir::PpAnn::nested(&(&tcx.hir() as &dyn hir::intravisit::Map<'_>), state, nested)
+        }
+    }
+}
+
+struct IdentifiedAnnotation<'hir> {
+    sess: &'hir Session,
+    tcx: Option<TyCtxt<'hir>>,
+}
+
+impl<'hir> PrinterSupport for IdentifiedAnnotation<'hir> {
+    fn sess(&self) -> &Session {
+        self.sess
+    }
+
+    fn pp_ann(&self) -> &dyn pprust::PpAnn {
+        self
+    }
+}
+
+impl<'hir> pprust::PpAnn for IdentifiedAnnotation<'hir> {
+    fn pre(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
+        if let pprust::AnnNode::Expr(_) = node {
+            s.popen();
+        }
+    }
+    fn post(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
+        match node {
+            pprust::AnnNode::Crate(_) | pprust::AnnNode::Ident(_) | pprust::AnnNode::Name(_) => {}
+
+            pprust::AnnNode::Item(item) => {
+                s.s.space();
+                s.synth_comment(item.id.to_string())
+            }
+            pprust::AnnNode::SubItem(id) => {
+                s.s.space();
+                s.synth_comment(id.to_string())
+            }
+            pprust::AnnNode::Block(blk) => {
+                s.s.space();
+                s.synth_comment(format!("block {}", blk.id))
+            }
+            pprust::AnnNode::Expr(expr) => {
+                s.s.space();
+                s.synth_comment(expr.id.to_string());
+                s.pclose()
+            }
+            pprust::AnnNode::Pat(pat) => {
+                s.s.space();
+                s.synth_comment(format!("pat {}", pat.id));
+            }
+        }
+    }
+}
+
+impl<'hir> HirPrinterSupport<'hir> for IdentifiedAnnotation<'hir> {
+    fn sess(&self) -> &Session {
+        self.sess
+    }
+
+    fn hir_map(&self) -> Option<hir_map::Map<'hir>> {
+        self.tcx.map(|tcx| tcx.hir())
+    }
+
+    fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
+        self
+    }
+}
+
+impl<'hir> pprust_hir::PpAnn for IdentifiedAnnotation<'hir> {
+    fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
+        if let Some(ref tcx) = self.tcx {
+            pprust_hir::PpAnn::nested(&(&tcx.hir() as &dyn hir::intravisit::Map<'_>), state, nested)
+        }
+    }
+    fn pre(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
+        if let pprust_hir::AnnNode::Expr(_) = node {
+            s.popen();
+        }
+    }
+    fn post(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
+        match node {
+            pprust_hir::AnnNode::Name(_) => {}
+            pprust_hir::AnnNode::Item(item) => {
+                s.s.space();
+                s.synth_comment(format!("hir_id: {}", item.hir_id()));
+            }
+            pprust_hir::AnnNode::SubItem(id) => {
+                s.s.space();
+                s.synth_comment(id.to_string());
+            }
+            pprust_hir::AnnNode::Block(blk) => {
+                s.s.space();
+                s.synth_comment(format!("block hir_id: {}", blk.hir_id));
+            }
+            pprust_hir::AnnNode::Expr(expr) => {
+                s.s.space();
+                s.synth_comment(format!("expr hir_id: {}", expr.hir_id));
+                s.pclose();
+            }
+            pprust_hir::AnnNode::Pat(pat) => {
+                s.s.space();
+                s.synth_comment(format!("pat hir_id: {}", pat.hir_id));
+            }
+            pprust_hir::AnnNode::Arm(arm) => {
+                s.s.space();
+                s.synth_comment(format!("arm hir_id: {}", arm.hir_id));
+            }
+        }
+    }
+}
+
+struct HygieneAnnotation<'a> {
+    sess: &'a Session,
+}
+
+impl<'a> PrinterSupport for HygieneAnnotation<'a> {
+    fn sess(&self) -> &Session {
+        self.sess
+    }
+
+    fn pp_ann(&self) -> &dyn pprust::PpAnn {
+        self
+    }
+}
+
+impl<'a> pprust::PpAnn for HygieneAnnotation<'a> {
+    fn post(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
+        match node {
+            pprust::AnnNode::Ident(&Ident { name, span }) => {
+                s.s.space();
+                s.synth_comment(format!("{}{:?}", name.as_u32(), span.ctxt()))
+            }
+            pprust::AnnNode::Name(&name) => {
+                s.s.space();
+                s.synth_comment(name.as_u32().to_string())
+            }
+            pprust::AnnNode::Crate(_) => {
+                s.s.hardbreak();
+                let verbose = self.sess.verbose();
+                s.synth_comment(rustc_span::hygiene::debug_hygiene_data(verbose));
+                s.s.hardbreak_if_not_bol();
+            }
+            _ => {}
+        }
+    }
+}
+
+struct TypedAnnotation<'tcx> {
+    tcx: TyCtxt<'tcx>,
+    maybe_typeck_results: Cell<Option<&'tcx ty::TypeckResults<'tcx>>>,
+}
+
+impl<'tcx> HirPrinterSupport<'tcx> for TypedAnnotation<'tcx> {
+    fn sess(&self) -> &Session {
+        self.tcx.sess
+    }
+
+    fn hir_map(&self) -> Option<hir_map::Map<'tcx>> {
+        Some(self.tcx.hir())
+    }
+
+    fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
+        self
+    }
+}
+
+impl<'tcx> pprust_hir::PpAnn for TypedAnnotation<'tcx> {
+    fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
+        let old_maybe_typeck_results = self.maybe_typeck_results.get();
+        if let pprust_hir::Nested::Body(id) = nested {
+            self.maybe_typeck_results.set(Some(self.tcx.typeck_body(id)));
+        }
+        let pp_ann = &(&self.tcx.hir() as &dyn hir::intravisit::Map<'_>);
+        pprust_hir::PpAnn::nested(pp_ann, state, nested);
+        self.maybe_typeck_results.set(old_maybe_typeck_results);
+    }
+    fn pre(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
+        if let pprust_hir::AnnNode::Expr(_) = node {
+            s.popen();
+        }
+    }
+    fn post(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
+        if let pprust_hir::AnnNode::Expr(expr) = node {
+            let typeck_results = self.maybe_typeck_results.get().or_else(|| {
+                self.tcx
+                    .hir()
+                    .maybe_body_owned_by(expr.hir_id.owner)
+                    .map(|body_id| self.tcx.typeck_body(body_id))
+            });
+
+            if let Some(typeck_results) = typeck_results {
+                s.s.space();
+                s.s.word("as");
+                s.s.space();
+                s.s.word(typeck_results.expr_ty(expr).to_string());
+            }
+
+            s.pclose();
+        }
+    }
+}
+
+fn get_source(input: &Input, sess: &Session) -> (String, FileName) {
+    let src_name = input.source_name();
+    let src = String::clone(
+        sess.source_map()
+            .get_source_file(&src_name)
+            .expect("get_source_file")
+            .src
+            .as_ref()
+            .expect("src"),
+    );
+    (src, src_name)
+}
+
+fn write_or_print(out: &str, ofile: Option<&Path>) {
+    match ofile {
+        None => print!("{}", out),
+        Some(p) => {
+            if let Err(e) = std::fs::write(p, out) {
+                panic!("print-print failed to write {} due to {}", p.display(), e);
+            }
+        }
+    }
+}
+
+pub fn print_after_parsing(
+    sess: &Session,
+    input: &Input,
+    krate: &ast::Crate,
+    ppm: PpMode,
+    ofile: Option<&Path>,
+) {
+    let (src, src_name) = get_source(input, sess);
+
+    let out = match ppm {
+        Source(s) => {
+            // Silently ignores an identified node.
+            call_with_pp_support(&s, sess, None, move |annotation| {
+                debug!("pretty printing source code {:?}", s);
+                let sess = annotation.sess();
+                let parse = &sess.parse_sess;
+                pprust::print_crate(
+                    sess.source_map(),
+                    krate,
+                    src_name,
+                    src,
+                    annotation.pp_ann(),
+                    false,
+                    parse.edition,
+                )
+            })
+        }
+        AstTree(PpAstTreeMode::Normal) => {
+            debug!("pretty printing AST tree");
+            format!("{:#?}", krate)
+        }
+        _ => unreachable!(),
+    };
+
+    write_or_print(&out, ofile);
+}
+
+pub fn print_after_hir_lowering<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    input: &Input,
+    krate: &ast::Crate,
+    ppm: PpMode,
+    ofile: Option<&Path>,
+) {
+    if ppm.needs_analysis() {
+        abort_on_err(print_with_analysis(tcx, ppm, ofile), tcx.sess);
+        return;
+    }
+
+    let (src, src_name) = get_source(input, tcx.sess);
+
+    let out = match ppm {
+        Source(s) => {
+            // Silently ignores an identified node.
+            call_with_pp_support(&s, tcx.sess, Some(tcx), move |annotation| {
+                debug!("pretty printing source code {:?}", s);
+                let sess = annotation.sess();
+                let parse = &sess.parse_sess;
+                pprust::print_crate(
+                    sess.source_map(),
+                    krate,
+                    src_name,
+                    src,
+                    annotation.pp_ann(),
+                    true,
+                    parse.edition,
+                )
+            })
+        }
+
+        AstTree(PpAstTreeMode::Expanded) => {
+            debug!("pretty-printing expanded AST");
+            format!("{:#?}", krate)
+        }
+
+        Hir(s) => call_with_pp_support_hir(&s, tcx, move |annotation, hir_map| {
+            debug!("pretty printing HIR {:?}", s);
+            let sess = annotation.sess();
+            let sm = sess.source_map();
+            let attrs = |id| hir_map.attrs(id);
+            pprust_hir::print_crate(
+                sm,
+                hir_map.root_module(),
+                src_name,
+                src,
+                &attrs,
+                annotation.pp_ann(),
+            )
+        }),
+
+        HirTree => {
+            call_with_pp_support_hir(&PpHirMode::Normal, tcx, move |_annotation, hir_map| {
+                debug!("pretty printing HIR tree");
+                format!("{:#?}", hir_map.krate())
+            })
+        }
+
+        _ => unreachable!(),
+    };
+
+    write_or_print(&out, ofile);
+}
+
+// In an ideal world, this would be a public function called by the driver after
+// analysis is performed. However, we want to call `phase_3_run_analysis_passes`
+// with a different callback than the standard driver, so that isn't easy.
+// Instead, we call that function ourselves.
+fn print_with_analysis(
+    tcx: TyCtxt<'_>,
+    ppm: PpMode,
+    ofile: Option<&Path>,
+) -> Result<(), ErrorGuaranteed> {
+    tcx.analysis(())?;
+    let out = match ppm {
+        Mir => {
+            let mut out = Vec::new();
+            write_mir_pretty(tcx, None, &mut out).unwrap();
+            String::from_utf8(out).unwrap()
+        }
+
+        MirCFG => {
+            let mut out = Vec::new();
+            write_mir_graphviz(tcx, None, &mut out).unwrap();
+            String::from_utf8(out).unwrap()
+        }
+
+        ThirTree => {
+            let mut out = String::new();
+            abort_on_err(rustc_typeck::check_crate(tcx), tcx.sess);
+            debug!("pretty printing THIR tree");
+            for did in tcx.hir().body_owners() {
+                let _ = writeln!(
+                    out,
+                    "{:?}:\n{}\n",
+                    did,
+                    tcx.thir_tree(ty::WithOptConstParam::unknown(did))
+                );
+            }
+            out
+        }
+
+        _ => unreachable!(),
+    };
+
+    write_or_print(&out, ofile);
+
+    Ok(())
+}