Print a backtrace in const eval if interrupted

Author: saethlin

Diff for: Cargo.lock

@@ -3413,6 +3413,7 @@ dependencies = [
 name = "rustc_driver_impl"
 version = "0.0.0"
 dependencies = [
+ "ctrlc",
  "libc",
  "rustc_ast",
  "rustc_ast_lowering",

Diff for: compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -1,8 +1,10 @@
 use crate::const_eval::CheckAlignment;
 use std::borrow::Cow;
+use std::sync::atomic::Ordering::Relaxed;
 
 use either::{Left, Right};
 
+use rustc_data_structures::CTRL_C_RECEIVED;
 use rustc_hir::def::DefKind;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::ErrorHandled;
@@ -66,7 +68,11 @@ fn eval_body_using_ecx<'mir, 'tcx>(
     )?;
 
     // The main interpreter loop.
-    while ecx.step()? {}
+    while ecx.step()? {
+        if CTRL_C_RECEIVED.load(Relaxed) {
+            throw_exhaust!(Interrupted);
+        }
+    }
 
     // Intern the result
     let intern_kind = if cid.promoted.is_some() {

Diff for: compiler/rustc_data_structures/src/lib.rs

@@ -46,6 +46,8 @@ extern crate cfg_if;
 #[macro_use]
 extern crate rustc_macros;
 
+use std::sync::atomic::AtomicBool;
+
 pub use rustc_index::static_assert_size;
 
 #[inline(never)]
@@ -129,3 +131,8 @@ impl<F: FnOnce()> Drop for OnDrop<F> {
 // See comments in src/librustc_middle/lib.rs
 #[doc(hidden)]
 pub fn __noop_fix_for_27438() {}
+
+/// `rustc_driver::main` installs a handler that will set this to `true` if
+/// the compiler has been sent a request to shut down, such as by a Ctrl-C.
+/// This static is placed here so that it is available to all parts of the compiler.
+pub static CTRL_C_RECEIVED: AtomicBool = AtomicBool::new(false);

Diff for: compiler/rustc_driver_impl/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 [lib]
 
 [dependencies]
+ctrlc = "3.3.0"
 tracing = { version = "0.1.35" }
 serde_json = "1.0.59"
 rustc_log = { path = "../rustc_log" }

Diff for: compiler/rustc_driver_impl/src/lib.rs

@@ -23,6 +23,7 @@ use rustc_data_structures::profiling::{
     get_resident_set_size, print_time_passes_entry, TimePassesFormat,
 };
 use rustc_data_structures::sync::SeqCst;
+use rustc_data_structures::CTRL_C_RECEIVED;
 use rustc_errors::registry::{InvalidErrorCode, Registry};
 use rustc_errors::{
     DiagnosticMessage, ErrorGuaranteed, Handler, PResult, SubdiagnosticMessage, TerminalUrl,
@@ -55,6 +56,7 @@ use std::panic::{self, catch_unwind};
 use std::path::PathBuf;
 use std::process::{self, Command, Stdio};
 use std::str;
+use std::sync::atomic::Ordering::Relaxed;
 use std::sync::OnceLock;
 use std::time::Instant;
 
@@ -1403,6 +1405,19 @@ pub fn main() -> ! {
     signal_handler::install();
     let mut callbacks = TimePassesCallbacks::default();
     install_ice_hook(DEFAULT_BUG_REPORT_URL, |_| ());
+
+    ctrlc::set_handler(move || {
+        // Indicate that we have been signaled to stop. If we were already signaled, exit
+        // immediately. In our interpreter loop we try to consult this value often, but if for
+        // whatever reason we don't get to that check or the cleanup we do upon finding that
+        // this bool has become true takes a long time, the exit here will promptly exit the
+        // process on the second Ctrl-C.
+        if CTRL_C_RECEIVED.swap(true, Relaxed) {
+            std::process::exit(1);
+        }
+    })
+    .expect("Unable to install ctrlc handler");
+
     let exit_code = catch_with_exit_code(|| {
         let args = env::args_os()
             .enumerate()

Diff for: compiler/rustc_middle/src/mir/interpret/error.rs

@@ -473,6 +473,8 @@ pub enum ResourceExhaustionInfo {
     MemoryExhausted,
     /// The address space (of the target) is full.
     AddressSpaceFull,
+    /// The compiler got an interrupt signal (a user ran out of patience).
+    Interrupted,
 }
 
 impl fmt::Display for ResourceExhaustionInfo {
@@ -491,6 +493,7 @@ impl fmt::Display for ResourceExhaustionInfo {
             AddressSpaceFull => {
                 write!(f, "there are no more free addresses in the address space")
             }
+            Interrupted => write!(f, "compilation was interrupted"),
         }
     }
 }

Diff for: src/tools/miri/src/concurrency/thread.rs

@@ -3,13 +3,14 @@
 use std::cell::RefCell;
 use std::collections::hash_map::Entry;
 use std::num::TryFromIntError;
-use std::sync::atomic::{AtomicBool, Ordering::Relaxed};
+use std::sync::atomic::Ordering::Relaxed;
 use std::task::Poll;
 use std::time::{Duration, SystemTime};
 
 use log::trace;
 
 use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::CTRL_C_RECEIVED;
 use rustc_hir::def_id::DefId;
 use rustc_index::{Idx, IndexVec};
 use rustc_middle::mir::Mutability;
@@ -1013,21 +1014,22 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     /// Run the core interpreter loop. Returns only when an interrupt occurs (an error or program
     /// termination).
     fn run_threads(&mut self) -> InterpResult<'tcx, !> {
-        static SIGNALED: AtomicBool = AtomicBool::new(false);
+        // In normal rustc, rustc_driver::main installs this handler. But we don't use that
+        // function, see src/bin/miri.rs.
         ctrlc::set_handler(move || {
-            // Indicate that we have ben signaled to stop. If we were already signaled, exit
+            // Indicate that we have been signaled to stop. If we were already signaled, exit
             // immediately. In our interpreter loop we try to consult this value often, but if for
             // whatever reason we don't get to that check or the cleanup we do upon finding that
             // this bool has become true takes a long time, the exit here will promptly exit the
             // process on the second Ctrl-C.
-            if SIGNALED.swap(true, Relaxed) {
+            if CTRL_C_RECEIVED.swap(true, Relaxed) {
                 std::process::exit(1);
             }
         })
-        .unwrap();
+        .expect("Unable to install ctrlc handler");
         let this = self.eval_context_mut();
         loop {
-            if SIGNALED.load(Relaxed) {
+            if CTRL_C_RECEIVED.load(Relaxed) {
                 this.machine.handle_abnormal_termination();
                 std::process::exit(1);
             }

Diff for: src/tools/tidy/src/deps.rs

@@ -134,6 +134,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "crossbeam-utils",
     "crypto-common",
     "cstr",
+    "ctrlc",
     "datafrog",
     "derive_more",
     "digest",
@@ -185,6 +186,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "memmap2",
     "memoffset",
     "miniz_oxide",
+    "nix",
     "num_cpus",
     "object",
     "odht",
@@ -281,6 +283,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "winapi-util",
     "winapi-x86_64-pc-windows-gnu",
     "windows",
+    "windows-sys",
     "windows-targets",
     "windows_aarch64_gnullvm",
     "windows_aarch64_msvc",