Stop telling people to submit bugs for internal feature ICEs

compiler/rustc_driver_impl/messages.ftl

@@ -1,5 +1,6 @@
 driver_impl_ice = the compiler unexpectedly panicked. this is a bug.
 driver_impl_ice_bug_report = we would appreciate a bug report: {$bug_report_url}
+driver_impl_ice_bug_report_internal_feature = using internal features is not supported and expected to cause internal compiler errors when used incorrectly
 driver_impl_ice_exclude_cargo_defaults = some of the compiler flags provided by cargo are hidden
 
 driver_impl_ice_flags = compiler flags: {$flags}

compiler/rustc_driver_impl/src/lib.rs

@@ -60,7 +60,7 @@ use std::path::PathBuf;
 use std::process::{self, Command, Stdio};
 use std::str;
 use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::OnceLock;
+use std::sync::{Arc, OnceLock};
 use std::time::{Instant, SystemTime};
 use time::format_description::well_known::Rfc3339;
 use time::OffsetDateTime;
@@ -224,11 +224,18 @@ pub struct RunCompiler<'a, 'b> {
     file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
     make_codegen_backend:
         Option<Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>>,
+    using_internal_features: Arc<std::sync::atomic::AtomicBool>,
 }
 
 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, make_codegen_backend: None }
+        Self {
+            at_args,
+            callbacks,
+            file_loader: None,
+            make_codegen_backend: None,
+            using_internal_features: Arc::default(),
+        }
     }
 
     /// Set a custom codegen backend.
@@ -260,9 +267,23 @@ impl<'a, 'b> RunCompiler<'a, 'b> {
         self
     }
 
+    /// Set the session-global flag that checks whether internal features have been used,
+    /// suppressing the message about submitting an issue in ICEs when enabled.
+    #[must_use]
+    pub fn set_using_internal_features(mut self, using_internal_features: Arc<AtomicBool>) -> Self {
+        self.using_internal_features = using_internal_features;
+        self
+    }
+
     /// Parse args and run the compiler.
     pub fn run(self) -> interface::Result<()> {
-        run_compiler(self.at_args, self.callbacks, self.file_loader, self.make_codegen_backend)
+        run_compiler(
+            self.at_args,
+            self.callbacks,
+            self.file_loader,
+            self.make_codegen_backend,
+            self.using_internal_features,
+        )
     }
 }
 
@@ -273,6 +294,7 @@ fn run_compiler(
     make_codegen_backend: Option<
         Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
     >,
+    using_internal_features: Arc<std::sync::atomic::AtomicBool>,
 ) -> interface::Result<()> {
     let mut early_error_handler = EarlyErrorHandler::new(ErrorOutputType::default());
 
@@ -316,6 +338,7 @@ fn run_compiler(
         override_queries: None,
         make_codegen_backend,
         registry: diagnostics_registry(),
+        using_internal_features,
         expanded_args: args,
     };
 
@@ -1323,8 +1346,12 @@ fn ice_path() -> &'static Option<PathBuf> {
 /// If you have no extra info to report, pass the empty closure `|_| ()` as the argument to
 /// extra_info.
 ///
+/// Returns a flag that can be set to disable the note for submitting a bug. This can be passed to
+/// [`RunCompiler::set_using_internal_features`] to let macro expansion set it when encountering
+/// internal features.
+///
 /// A custom rustc driver can skip calling this to set up a custom ICE hook.
-pub fn install_ice_hook(bug_report_url: &'static str, extra_info: fn(&Handler)) {
+pub fn install_ice_hook(bug_report_url: &'static str, extra_info: fn(&Handler)) -> Arc<AtomicBool> {
     // 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
@@ -1335,6 +1362,8 @@ pub fn install_ice_hook(bug_report_url: &'static str, extra_info: fn(&Handler))
         std::env::set_var("RUST_BACKTRACE", "full");
     }
 
+    let using_internal_features = Arc::new(std::sync::atomic::AtomicBool::default());
+    let using_internal_features_hook = using_internal_features.clone();
     panic::update_hook(Box::new(
         move |default_hook: &(dyn Fn(&PanicInfo<'_>) + Send + Sync + 'static),
               info: &PanicInfo<'_>| {
@@ -1384,9 +1413,11 @@ pub fn install_ice_hook(bug_report_url: &'static str, extra_info: fn(&Handler))
             }
 
             // Print the ICE message
-            report_ice(info, bug_report_url, extra_info);
+            report_ice(info, bug_report_url, extra_info, &using_internal_features_hook);
         },
     ));
+
+    using_internal_features
 }
 
 /// Prints the ICE message, including query stack, but without backtrace.
@@ -1395,7 +1426,12 @@ pub fn install_ice_hook(bug_report_url: &'static str, extra_info: fn(&Handler))
 ///
 /// When `install_ice_hook` is called, this function will be called as the panic
 /// hook.
-fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str, extra_info: fn(&Handler)) {
+fn report_ice(
+    info: &panic::PanicInfo<'_>,
+    bug_report_url: &str,
+    extra_info: fn(&Handler),
+    using_internal_features: &AtomicBool,
+) {
     let fallback_bundle =
         rustc_errors::fallback_fluent_bundle(crate::DEFAULT_LOCALE_RESOURCES.to_vec(), false);
     let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr(
@@ -1412,7 +1448,11 @@ fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str, extra_info: fn(
         handler.emit_err(session_diagnostics::Ice);
     }
 
-    handler.emit_note(session_diagnostics::IceBugReport { bug_report_url });
+    if using_internal_features.load(std::sync::atomic::Ordering::Relaxed) {
+        handler.emit_note(session_diagnostics::IceBugReportInternalFeature);
+    } else {
+        handler.emit_note(session_diagnostics::IceBugReport { bug_report_url });
+    }
 
     let version = util::version_str!().unwrap_or("unknown_version");
     let triple = config::host_triple();
@@ -1496,7 +1536,7 @@ pub fn main() -> ! {
     init_rustc_env_logger(&handler);
     signal_handler::install();
     let mut callbacks = TimePassesCallbacks::default();
-    install_ice_hook(DEFAULT_BUG_REPORT_URL, |_| ());
+    let using_internal_features = install_ice_hook(DEFAULT_BUG_REPORT_URL, |_| ());
     let exit_code = catch_with_exit_code(|| {
         let args = env::args_os()
             .enumerate()
@@ -1506,7 +1546,9 @@ pub fn main() -> ! {
                 })
             })
             .collect::<Vec<_>>();
-        RunCompiler::new(&args, &mut callbacks).run()
+        RunCompiler::new(&args, &mut callbacks)
+            .set_using_internal_features(using_internal_features)
+            .run()
     });
 
     if let Some(format) = callbacks.time_passes {

compiler/rustc_driver_impl/src/session_diagnostics.rs

@@ -42,6 +42,10 @@ pub(crate) struct IceBugReport<'a> {
     pub bug_report_url: &'a str,
 }
 
+#[derive(Diagnostic)]
+#[diag(driver_impl_ice_bug_report_internal_feature)]
+pub(crate) struct IceBugReportInternalFeature;
+
 #[derive(Diagnostic)]
 #[diag(driver_impl_ice_version)]
 pub(crate) struct IceVersion<'a> {

compiler/rustc_expand/src/config.rs

@@ -35,7 +35,7 @@ pub struct StripUnconfigured<'a> {
     pub lint_node_id: NodeId,
 }
 
-pub fn features(sess: &Session, krate_attrs: &[Attribute]) -> Features {
+pub fn features(sess: &Session, krate_attrs: &[Attribute], crate_name: Symbol) -> Features {
     fn feature_list(attr: &Attribute) -> ThinVec<ast::NestedMetaItem> {
         if attr.has_name(sym::feature)
             && let Some(list) = attr.meta_item_list()
@@ -167,6 +167,15 @@ pub fn features(sess: &Session, krate_attrs: &[Attribute]) -> Features {
             // If the declared feature is unstable, record it.
             if let Some(f) = UNSTABLE_FEATURES.iter().find(|f| name == f.feature.name) {
                 (f.set_enabled)(&mut features);
+                // When the ICE comes from core, alloc or std (approximation of the standard library), there's a chance
+                // that the person hitting the ICE may be using -Zbuild-std or similar with an untested target.
+                // The bug is probably in the standard library and not the compiler in that case, but that doesn't
+                // really matter - we want a bug report.
+                if features.internal(name)
+                    && ![sym::core, sym::alloc, sym::std].contains(&crate_name)
+                {
+                    sess.using_internal_features.store(true, std::sync::atomic::Ordering::Relaxed);
+                }
                 features.set_declared_lang_feature(name, mi.span(), None);
                 continue;
             }

compiler/rustc_interface/src/interface.rs

@@ -23,6 +23,7 @@ use rustc_span::source_map::{FileLoader, FileName};
 use rustc_span::symbol::sym;
 use std::path::PathBuf;
 use std::result;
+use std::sync::Arc;
 
 pub type Result<T> = result::Result<T, ErrorGuaranteed>;
 
@@ -280,6 +281,12 @@ pub struct Config {
     /// Registry of diagnostics codes.
     pub registry: Registry,
 
+    /// The inner atomic value is set to true when a feature marked as `internal` is
+    /// enabled. Makes it so that "please report a bug" is hidden, as ICEs with
+    /// internal features are wontfix, and they are usually the cause of the ICEs.
+    /// None signifies that this is not tracked.
+    pub using_internal_features: Arc<std::sync::atomic::AtomicBool>,
+
     /// All commandline args used to invoke the compiler, with @file args fully expanded.
     /// This will only be used within debug info, e.g. in the pdb file on windows
     /// This is mainly useful for other tools that reads that debuginfo to figure out
@@ -323,6 +330,7 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
                 config.make_codegen_backend,
                 registry.clone(),
                 config.ice_file,
+                config.using_internal_features,
                 config.expanded_args,
             );
 

compiler/rustc_interface/src/queries.rs

@@ -181,9 +181,11 @@ impl<'tcx> Queries<'tcx> {
                 feed.crate_name(crate_name);
 
                 let feed = tcx.feed_unit_query();
-                feed.features_query(
-                    tcx.arena.alloc(rustc_expand::config::features(sess, &pre_configured_attrs)),
-                );
+                feed.features_query(tcx.arena.alloc(rustc_expand::config::features(
+                    sess,
+                    &pre_configured_attrs,
+                    crate_name,
+                )));
                 feed.crate_for_resolver(tcx.arena.alloc(Steal::new((krate, pre_configured_attrs))));
             });
             Ok(qcx)

compiler/rustc_interface/src/tests.rs

@@ -35,6 +35,7 @@ use rustc_target::spec::{RelroLevel, SanitizerSet, SplitDebuginfo, StackProtecto
 use std::collections::{BTreeMap, BTreeSet};
 use std::num::NonZeroUsize;
 use std::path::{Path, PathBuf};
+use std::sync::Arc;
 
 type CfgSpecs = FxHashSet<(String, Option<String>)>;
 
@@ -69,6 +70,7 @@ fn mk_session(handler: &mut EarlyErrorHandler, matches: getopts::Matches) -> (Se
         None,
         "",
         None,
+        Arc::default(),
         Default::default(),
     );
     (sess, cfg)

compiler/rustc_interface/src/util.rs

@@ -26,7 +26,7 @@ use std::env::consts::{DLL_PREFIX, DLL_SUFFIX};
 use std::mem;
 use std::path::{Path, PathBuf};
 use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::OnceLock;
+use std::sync::{Arc, OnceLock};
 use std::thread;
 
 /// Function pointer type that constructs a new CodegenBackend.
@@ -71,6 +71,7 @@ pub fn create_session(
     >,
     descriptions: Registry,
     ice_file: Option<PathBuf>,
+    using_internal_features: Arc<AtomicBool>,
     expanded_args: Vec<String>,
 ) -> (Session, Box<dyn CodegenBackend>) {
     let codegen_backend = if let Some(make_codegen_backend) = make_codegen_backend {
@@ -114,6 +115,7 @@ pub fn create_session(
         target_override,
         rustc_version_str().unwrap_or("unknown"),
         ice_file,
+        using_internal_features,
         expanded_args,
     );
 

compiler/rustc_session/src/session.rs

@@ -44,7 +44,7 @@ use std::fmt;
 use std::ops::{Div, Mul};
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
-use std::sync::Arc;
+use std::sync::{atomic::AtomicBool, Arc};
 use std::time::Duration;
 
 pub struct OptimizationFuel {
@@ -201,6 +201,12 @@ pub struct Session {
     /// The version of the rustc process, possibly including a commit hash and description.
     pub cfg_version: &'static str,
 
+    /// The inner atomic value is set to true when a feature marked as `internal` is
+    /// enabled. Makes it so that "please report a bug" is hidden, as ICEs with
+    /// internal features are wontfix, and they are usually the cause of the ICEs.
+    /// None signifies that this is not tracked.
+    pub using_internal_features: Arc<AtomicBool>,
+
     /// All commandline args used to invoke the compiler, with @file args fully expanded.
     /// This will only be used within debug info, e.g. in the pdb file on windows
     /// This is mainly useful for other tools that reads that debuginfo to figure out
@@ -1333,6 +1339,7 @@ pub fn build_session(
     target_override: Option<Target>,
     cfg_version: &'static str,
     ice_file: Option<PathBuf>,
+    using_internal_features: Arc<AtomicBool>,
     expanded_args: Vec<String>,
 ) -> Session {
     // FIXME: This is not general enough to make the warning lint completely override
@@ -1469,6 +1476,7 @@ pub fn build_session(
         target_features: Default::default(),
         unstable_target_features: Default::default(),
         cfg_version,
+        using_internal_features,
         expanded_args,
     };
 

src/librustdoc/core.rs

@@ -23,6 +23,7 @@ use std::cell::RefCell;
 use std::mem;
 use std::rc::Rc;
 use std::sync::LazyLock;
+use std::sync::{atomic::AtomicBool, Arc};
 
 use crate::clean::inline::build_external_trait;
 use crate::clean::{self, ItemId};
@@ -198,6 +199,7 @@ pub(crate) fn create_config(
         ..
     }: RustdocOptions,
     RenderOptions { document_private, .. }: &RenderOptions,
+    using_internal_features: Arc<AtomicBool>,
 ) -> rustc_interface::Config {
     // Add the doc cfg into the doc build.
     cfgs.push("doc".to_string());
@@ -292,6 +294,7 @@ pub(crate) fn create_config(
         make_codegen_backend: None,
         registry: rustc_driver::diagnostics_registry(),
         ice_file: None,
+        using_internal_features,
         expanded_args,
     }
 }

src/librustdoc/doctest.rs

@@ -109,6 +109,7 @@ pub(crate) fn run(options: RustdocOptions) -> Result<(), ErrorGuaranteed> {
         make_codegen_backend: None,
         registry: rustc_driver::diagnostics_registry(),
         ice_file: None,
+        using_internal_features: Arc::default(),
         expanded_args: options.expanded_args.clone(),
     };