Rollup of 7 pull requests

Cargo.lock

@@ -4093,6 +4093,7 @@ dependencies = [
 name = "rustc_smir"
 version = "0.0.0"
 dependencies = [
+ "rustc_hir",
  "rustc_middle",
  "rustc_span",
  "tracing",

compiler/rustc_codegen_llvm/src/debuginfo/mod.rs

@@ -322,7 +322,7 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         let tcx = self.tcx;
 
         let def_id = instance.def_id();
-        let containing_scope = get_containing_scope(self, instance);
+        let (containing_scope, is_method) = get_containing_scope(self, instance);
         let span = tcx.def_span(def_id);
         let loc = self.lookup_debug_loc(span.lo());
         let file_metadata = file_metadata(self, &loc.file);
@@ -378,8 +378,29 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             }
         }
 
-        unsafe {
-            return llvm::LLVMRustDIBuilderCreateFunction(
+        // When we're adding a method to a type DIE, we only want a DW_AT_declaration there, because
+        // LLVM LTO can't unify type definitions when a child DIE is a full subprogram definition.
+        // When we use this `decl` below, the subprogram definition gets created at the CU level
+        // with a DW_AT_specification pointing back to the type's declaration.
+        let decl = is_method.then(|| unsafe {
+            llvm::LLVMRustDIBuilderCreateMethod(
+                DIB(self),
+                containing_scope,
+                name.as_ptr().cast(),
+                name.len(),
+                linkage_name.as_ptr().cast(),
+                linkage_name.len(),
+                file_metadata,
+                loc.line,
+                function_type_metadata,
+                flags,
+                spflags & !DISPFlags::SPFlagDefinition,
+                template_parameters,
+            )
+        });
+
+        return unsafe {
+            llvm::LLVMRustDIBuilderCreateFunction(
                 DIB(self),
                 containing_scope,
                 name.as_ptr().cast(),
@@ -394,9 +415,9 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                 spflags,
                 maybe_definition_llfn,
                 template_parameters,
-                None,
-            );
-        }
+                decl,
+            )
+        };
 
         fn get_function_signature<'ll, 'tcx>(
             cx: &CodegenCx<'ll, 'tcx>,
@@ -493,14 +514,16 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             names
         }
 
+        /// Returns a scope, plus `true` if that's a type scope for "class" methods,
+        /// otherwise `false` for plain namespace scopes.
         fn get_containing_scope<'ll, 'tcx>(
             cx: &CodegenCx<'ll, 'tcx>,
             instance: Instance<'tcx>,
-        ) -> &'ll DIScope {
+        ) -> (&'ll DIScope, bool) {
             // First, let's see if this is a method within an inherent impl. Because
             // if yes, we want to make the result subroutine DIE a child of the
             // subroutine's self-type.
-            let self_type = cx.tcx.impl_of_method(instance.def_id()).and_then(|impl_def_id| {
+            if let Some(impl_def_id) = cx.tcx.impl_of_method(instance.def_id()) {
                 // If the method does *not* belong to a trait, proceed
                 if cx.tcx.trait_id_of_impl(impl_def_id).is_none() {
                     let impl_self_ty = cx.tcx.subst_and_normalize_erasing_regions(
@@ -511,39 +534,33 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
 
                     // Only "class" methods are generally understood by LLVM,
                     // so avoid methods on other types (e.g., `<*mut T>::null`).
-                    match impl_self_ty.kind() {
-                        ty::Adt(def, ..) if !def.is_box() => {
-                            // Again, only create type information if full debuginfo is enabled
-                            if cx.sess().opts.debuginfo == DebugInfo::Full
-                                && !impl_self_ty.has_param()
-                            {
-                                Some(type_di_node(cx, impl_self_ty))
-                            } else {
-                                Some(namespace::item_namespace(cx, def.did()))
-                            }
+                    if let ty::Adt(def, ..) = impl_self_ty.kind() && !def.is_box() {
+                        // Again, only create type information if full debuginfo is enabled
+                        if cx.sess().opts.debuginfo == DebugInfo::Full && !impl_self_ty.has_param()
+                        {
+                            return (type_di_node(cx, impl_self_ty), true);
+                        } else {
+                            return (namespace::item_namespace(cx, def.did()), false);
                         }
-                        _ => None,
                     }
                 } else {
                     // For trait method impls we still use the "parallel namespace"
                     // strategy
-                    None
                 }
-            });
+            }
 
-            self_type.unwrap_or_else(|| {
-                namespace::item_namespace(
-                    cx,
-                    DefId {
-                        krate: instance.def_id().krate,
-                        index: cx
-                            .tcx
-                            .def_key(instance.def_id())
-                            .parent
-                            .expect("get_containing_scope: missing parent?"),
-                    },
-                )
-            })
+            let scope = namespace::item_namespace(
+                cx,
+                DefId {
+                    krate: instance.def_id().krate,
+                    index: cx
+                        .tcx
+                        .def_key(instance.def_id())
+                        .parent
+                        .expect("get_containing_scope: missing parent?"),
+                },
+            );
+            (scope, false)
         }
     }
 

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -1987,6 +1987,21 @@ extern "C" {
         Decl: Option<&'a DIDescriptor>,
     ) -> &'a DISubprogram;
 
+    pub fn LLVMRustDIBuilderCreateMethod<'a>(
+        Builder: &DIBuilder<'a>,
+        Scope: &'a DIDescriptor,
+        Name: *const c_char,
+        NameLen: size_t,
+        LinkageName: *const c_char,
+        LinkageNameLen: size_t,
+        File: &'a DIFile,
+        LineNo: c_uint,
+        Ty: &'a DIType,
+        Flags: DIFlags,
+        SPFlags: DISPFlags,
+        TParam: &'a DIArray,
+    ) -> &'a DISubprogram;
+
     pub fn LLVMRustDIBuilderCreateBasicType<'a>(
         Builder: &DIBuilder<'a>,
         Name: *const c_char,

compiler/rustc_driver_impl/src/lib.rs

@@ -25,7 +25,7 @@ use rustc_data_structures::profiling::{
 use rustc_data_structures::sync::SeqCst;
 use rustc_errors::registry::{InvalidErrorCode, Registry};
 use rustc_errors::{
-    DiagnosticMessage, ErrorGuaranteed, PResult, SubdiagnosticMessage, TerminalUrl,
+    DiagnosticMessage, ErrorGuaranteed, Handler, PResult, SubdiagnosticMessage, TerminalUrl,
 };
 use rustc_feature::find_gated_cfg;
 use rustc_fluent_macro::fluent_messages;
@@ -55,7 +55,7 @@ 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::sync::OnceLock;
 use std::time::Instant;
 
 // This import blocks the use of panicking `print` and `println` in all the code
@@ -119,7 +119,7 @@ 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\
+pub const DEFAULT_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"];
@@ -1196,43 +1196,66 @@ pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 {
     }
 }
 
-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| {
-            // If the error was caused by a broken pipe then this is not a bug.
-            // Write the error and return immediately. See #98700.
-            #[cfg(windows)]
-            if let Some(msg) = info.payload().downcast_ref::<String>() {
-                if msg.starts_with("failed printing to stdout: ") && msg.ends_with("(os error 232)")
-                {
-                    early_error_no_abort(ErrorOutputType::default(), &msg);
-                    return;
-                }
-            };
+/// Stores the default panic hook, from before [`install_ice_hook`] was called.
+static DEFAULT_HOOK: OnceLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> =
+    OnceLock::new();
+
+/// Installs a panic hook that will print the ICE message on unexpected panics.
+///
+/// The hook is intended to be useable even by external tools. You can pass a custom
+/// `bug_report_url`, or report arbitrary info in `extra_info`. Note that `extra_info` is called in
+/// a context where *the thread is currently panicking*, so it must not panic or the process will
+/// abort.
+///
+/// If you have no extra info to report, pass the empty closure `|_| ()` as the argument to
+/// extra_info.
+///
+/// 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)) {
+    // 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");
+    }
 
-            // Invoke the default handler, which prints the actual panic message and optionally a backtrace
-            // Don't do this for delayed bugs, which already emit their own more useful backtrace.
-            if !info.payload().is::<rustc_errors::DelayedBugPanic>() {
-                (*DEFAULT_HOOK)(info);
+    let default_hook = DEFAULT_HOOK.get_or_init(panic::take_hook);
 
-                // Separate the output with an empty line
-                eprintln!();
+    panic::set_hook(Box::new(move |info| {
+        // If the error was caused by a broken pipe then this is not a bug.
+        // Write the error and return immediately. See #98700.
+        #[cfg(windows)]
+        if let Some(msg) = info.payload().downcast_ref::<String>() {
+            if msg.starts_with("failed printing to stdout: ") && msg.ends_with("(os error 232)") {
+                early_error_no_abort(ErrorOutputType::default(), &msg);
+                return;
             }
+        };
 
-            // Print the ICE message
-            report_ice(info, BUG_REPORT_URL);
-        }));
-        hook
-    });
+        // Invoke the default handler, which prints the actual panic message and optionally a backtrace
+        // Don't do this for delayed bugs, which already emit their own more useful backtrace.
+        if !info.payload().is::<rustc_errors::DelayedBugPanic>() {
+            (*default_hook)(info);
+
+            // Separate the output with an empty line
+            eprintln!();
+        }
+
+        // Print the ICE message
+        report_ice(info, bug_report_url, extra_info);
+    }));
+}
 
 /// 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) {
+pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str, extra_info: fn(&Handler)) {
     let fallback_bundle =
         rustc_errors::fallback_fluent_bundle(crate::DEFAULT_LOCALE_RESOURCES.to_vec(), false);
     let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr(
@@ -1277,29 +1300,17 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
 
     interface::try_print_query_stack(&handler, num_frames);
 
+    // We don't trust this callback not to panic itself, so run it at the end after we're sure we've
+    // printed all the relevant info.
+    extra_info(&handler);
+
     #[cfg(windows)]
     if env::var("RUSTC_BREAK_ON_ICE").is_ok() {
         // Trigger a debugger if we crashed during bootstrap
         unsafe { windows::Win32::System::Diagnostics::Debug::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() {
@@ -1370,7 +1381,7 @@ pub fn main() -> ! {
     init_rustc_env_logger();
     signal_handler::install();
     let mut callbacks = TimePassesCallbacks::default();
-    install_ice_hook();
+    install_ice_hook(DEFAULT_BUG_REPORT_URL, |_| ());
     let exit_code = catch_with_exit_code(|| {
         let args = env::args_os()
             .enumerate()