Auto merge of rust-lang#127067 - matthiaskrgr:rollup-85ecygb, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - rust-lang#124741 (patchable-function-entry: Add unstable compiler flag and attribute)
 - rust-lang#126470 (make cargo submodule optional)
 - rust-lang#126701 (ignore `llvm::Lld` if lld is not enabled)
 - rust-lang#126956 (core: avoid `extern type`s in formatting infrastructure)
 - rust-lang#126970 (Simplify `str::clone_into`)
 - rust-lang#127058 (Tighten `fn_decl_span` for async blocks)

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

Author: bors

compiler/rustc_interface/src/tests.rs

@@ -8,8 +8,8 @@ use rustc_session::config::{
     ErrorOutputType, ExternEntry, ExternLocation, Externs, FunctionReturn, InliningThreshold,
     Input, InstrumentCoverage, InstrumentXRay, LinkSelfContained, LinkerPluginLto, LocationDetail,
     LtoCli, NextSolverConfig, OomStrategy, Options, OutFileName, OutputType, OutputTypes, PAuthKey,
-    PacRet, Passes, Polonius, ProcMacroExecutionStrategy, Strip, SwitchWithOptPath,
-    SymbolManglingVersion, WasiExecModel,
+    PacRet, Passes, PatchableFunctionEntry, Polonius, ProcMacroExecutionStrategy, Strip,
+    SwitchWithOptPath, SymbolManglingVersion, WasiExecModel,
 };
 use rustc_session::lint::Level;
 use rustc_session::search_paths::SearchPath;
@@ -813,6 +813,11 @@ fn test_unstable_options_tracking_hash() {
     tracked!(packed_bundled_libs, true);
     tracked!(panic_abort_tests, true);
     tracked!(panic_in_drop, PanicStrategy::Abort);
+    tracked!(
+        patchable_function_entry,
+        PatchableFunctionEntry::from_total_and_prefix_nops(10, 5)
+            .expect("total must be greater than or equal to prefix")
+    );
     tracked!(plt, Some(true));
     tracked!(polonius, Polonius::Legacy);
     tracked!(precise_enum_drop_elaboration, false);

compiler/rustc_middle/src/middle/codegen_fn_attrs.rs

@@ -45,6 +45,32 @@ pub struct CodegenFnAttrs {
     /// The `#[repr(align(...))]` attribute. Indicates the value of which the function should be
     /// aligned to.
     pub alignment: Option<Align>,
+    /// The `#[patchable_function_entry(...)]` attribute. Indicates how many nops should be around
+    /// the function entry.
+    pub patchable_function_entry: Option<PatchableFunctionEntry>,
+}
+
+#[derive(Copy, Clone, Debug, TyEncodable, TyDecodable, HashStable)]
+pub struct PatchableFunctionEntry {
+    /// Nops to prepend to the function
+    prefix: u8,
+    /// Nops after entry, but before body
+    entry: u8,
+}
+
+impl PatchableFunctionEntry {
+    pub fn from_config(config: rustc_session::config::PatchableFunctionEntry) -> Self {
+        Self { prefix: config.prefix(), entry: config.entry() }
+    }
+    pub fn from_prefix_and_entry(prefix: u8, entry: u8) -> Self {
+        Self { prefix, entry }
+    }
+    pub fn prefix(&self) -> u8 {
+        self.prefix
+    }
+    pub fn entry(&self) -> u8 {
+        self.entry
+    }
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, TyEncodable, TyDecodable, HashStable)]
@@ -121,6 +147,7 @@ impl CodegenFnAttrs {
             no_sanitize: SanitizerSet::empty(),
             instruction_set: None,
             alignment: None,
+            patchable_function_entry: None,
         }
     }