Auto merge of #106070 - matthiaskrgr:rollup-jv9ctkl, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #105978 (Mark `proc_macro_decls_static` as always used)
 - #106051 (Allow building std with cranelift)
 - #106056 (Make `sess.bug` much less noisy)
 - #106057 (Give a more helpful error for "trimmed_def_paths constructed")
 - #106058 (Fix the issue number in comment for as_local_call_operand)
 - #106059 (Avoid running the `Profile` step twice on `x setup`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Cargo.lock

@@ -4129,6 +4129,7 @@ dependencies = [
  "rustc_ast",
  "rustc_attr",
  "rustc_data_structures",
+ "rustc_error_messages",
  "rustc_errors",
  "rustc_feature",
  "rustc_graphviz",

compiler/rustc_builtin_macros/src/proc_macro_harness.rs

@@ -262,6 +262,7 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
 //          use proc_macro::bridge::client::ProcMacro;
 //
 //          #[rustc_proc_macro_decls]
+//          #[used]
 //          #[allow(deprecated)]
 //          static DECLS: &[ProcMacro] = &[
 //              ProcMacro::custom_derive($name_trait1, &[], ::$name1);
@@ -364,6 +365,7 @@ fn mk_decls(cx: &mut ExtCtxt<'_>, macros: &[ProcMacro]) -> P<ast::Item> {
         )
         .map(|mut i| {
             i.attrs.push(cx.attr_word(sym::rustc_proc_macro_decls, span));
+            i.attrs.push(cx.attr_word(sym::used, span));
             i.attrs.push(cx.attr_nested_word(sym::allow, sym::deprecated, span));
             i
         });

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -567,7 +567,7 @@ fn codegen_msvc_try<'ll>(
         // module.
         //
         // When modifying, make sure that the type_name string exactly matches
-        // the one used in src/libpanic_unwind/seh.rs.
+        // the one used in library/panic_unwind/src/seh.rs.
         let type_info_vtable = bx.declare_global("??_7type_info@@6B@", bx.type_i8p());
         let type_name = bx.const_bytes(b"rust_panic\0");
         let type_info =

compiler/rustc_driver/src/lib.rs

@@ -1199,10 +1199,13 @@ static DEFAULT_HOOK: LazyLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send +
             };
 
             // Invoke the default handler, which prints the actual panic message and optionally a backtrace
-            (*DEFAULT_HOOK)(info);
+            // Don't do this for `ExplicitBug`, which has an unhelpful message and backtrace.
+            if !info.payload().is::<rustc_errors::ExplicitBug>() {
+                (*DEFAULT_HOOK)(info);
 
-            // Separate the output with an empty line
-            eprintln!();
+                // Separate the output with an empty line
+                eprintln!();
+            }
 
             // Print the ICE message
             report_ice(info, BUG_REPORT_URL);

compiler/rustc_error_messages/src/lib.rs

@@ -381,7 +381,7 @@ impl<S: Into<String>> From<S> for DiagnosticMessage {
     }
 }
 
-/// A workaround for "good path" ICEs when formatting types in disables lints.
+/// A workaround for "good path" ICEs when formatting types in disabled lints.
 ///
 /// Delays formatting until `.into(): DiagnosticMessage` is used.
 pub struct DelayDm<F>(pub F);

compiler/rustc_middle/Cargo.toml

@@ -18,6 +18,8 @@ rustc_ast = { path = "../rustc_ast" }
 rustc_attr = { path = "../rustc_attr" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
+# Used for intra-doc links
+rustc_error_messages = { path = "../rustc_error_messages" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_graphviz = { path = "../rustc_graphviz" }
 rustc_hir = { path = "../rustc_hir" }

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -2883,13 +2883,19 @@ fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, N
 /// `std::vec::Vec` to just `Vec`, as long as there is no other `Vec` importable anywhere.
 ///
 /// The implementation uses similar import discovery logic to that of 'use' suggestions.
+///
+/// See also [`DelayDm`](rustc_error_messages::DelayDm) and [`with_no_trimmed_paths`].
 fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> FxHashMap<DefId, Symbol> {
     let mut map: FxHashMap<DefId, Symbol> = FxHashMap::default();
 
     if let TrimmedDefPaths::GoodPath = tcx.sess.opts.trimmed_def_paths {
+        // Trimming paths is expensive and not optimized, since we expect it to only be used for error reporting.
+        //
         // For good paths causing this bug, the `rustc_middle::ty::print::with_no_trimmed_paths`
         // wrapper can be used to suppress this query, in exchange for full paths being formatted.
-        tcx.sess.delay_good_path_bug("trimmed_def_paths constructed");
+        tcx.sess.delay_good_path_bug(
+            "trimmed_def_paths constructed but no error emitted; use `DelayDm` for lints or `with_no_trimmed_paths` for debugging",
+        );
     }
 
     let unique_symbols_rev: &mut FxHashMap<(Namespace, Symbol), Option<DefId>> =

compiler/rustc_mir_build/src/build/expr/as_operand.rs

@@ -72,7 +72,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     /// will actually provide a pointer to the interior of the box, and not move the `dyn Debug`
     /// value to the stack.
     ///
-    /// See #68034 for more details.
+    /// See #68304 for more details.
     pub(crate) fn as_local_call_operand(
         &mut self,
         block: BasicBlock,

src/bootstrap/builder.rs

@@ -1864,7 +1864,10 @@ impl<'a> Builder<'a> {
             };
 
             if let Some(limit) = limit {
-                rustflags.arg(&format!("-Cllvm-args=-import-instr-limit={}", limit));
+                if stage == 0 || self.config.default_codegen_backend().unwrap_or_default() == "llvm"
+                {
+                    rustflags.arg(&format!("-Cllvm-args=-import-instr-limit={}", limit));
+                }
             }
         }
 

src/bootstrap/compile.rs

@@ -321,8 +321,15 @@ pub fn std_cargo(builder: &Builder<'_>, target: TargetSelection, stage: u32, car
         ""
     };
 
+    let mut features = String::new();
+
+    // Cranelift doesn't support `asm`.
+    if stage != 0 && builder.config.default_codegen_backend().unwrap_or_default() == "cranelift" {
+        features += " compiler-builtins-no-asm";
+    }
+
     if builder.no_std(target) == Some(true) {
-        let mut features = "compiler-builtins-mem".to_string();
+        features += " compiler-builtins-mem";
         if !target.starts_with("bpf") {
             features.push_str(compiler_builtins_c_feature);
         }
@@ -335,7 +342,7 @@ pub fn std_cargo(builder: &Builder<'_>, target: TargetSelection, stage: u32, car
             .arg("--features")
             .arg(features);
     } else {
-        let mut features = builder.std_features(target);
+        features += &builder.std_features(target);
         features.push_str(compiler_builtins_c_feature);
 
         cargo
@@ -754,7 +761,7 @@ pub fn rustc_cargo_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetS
         .env("CFG_RELEASE_CHANNEL", &builder.config.channel)
         .env("CFG_VERSION", builder.rust_version());
 
-    if let Some(backend) = builder.config.rust_codegen_backends.get(0) {
+    if let Some(backend) = builder.config.default_codegen_backend() {
         cargo.env("CFG_DEFAULT_CODEGEN_BACKEND", backend);
     }
 

src/bootstrap/config.rs

@@ -1611,6 +1611,10 @@ impl Config {
         self.submodules.unwrap_or(rust_info.is_managed_git_subrepository())
     }
 
+    pub fn default_codegen_backend(&self) -> Option<Interned<String>> {
+        self.rust_codegen_backends.get(0).cloned()
+    }
+
     /// Returns the commit to download, or `None` if we shouldn't download CI artifacts.
     fn download_ci_rustc_commit(&self, download_rustc: Option<StringOrBool>) -> Option<String> {
         // If `download-rustc` is not set, default to rebuilding.

src/bootstrap/lib.rs

@@ -796,7 +796,7 @@ impl Build {
     /// Gets the space-separated set of activated features for the standard
     /// library.
     fn std_features(&self, target: TargetSelection) -> String {
-        let mut features = "panic-unwind".to_string();
+        let mut features = " panic-unwind".to_string();
 
         match self.config.llvm_libunwind(target) {
             LlvmLibunwind::InTree => features.push_str(" llvm-libunwind"),

src/bootstrap/setup.rs

@@ -96,6 +96,10 @@ impl Step for Profile {
     }
 
     fn make_run(run: RunConfig<'_>) {
+        if run.builder.config.dry_run() {
+            return;
+        }
+
         // for Profile, `run.paths` will have 1 and only 1 element
         // this is because we only accept at most 1 path from user input.
         // If user calls `x.py setup` without arguments, the interactive TUI

src/test/ui/proc-macro/quote-debug.stdout

@@ -42,6 +42,7 @@ const _: () =
     {
         extern crate proc_macro;
         #[rustc_proc_macro_decls]
+        #[used]
         #[allow(deprecated)]
         static _DECLS: &[proc_macro::bridge::client::ProcMacro] = &[];
     };