From 972663d8ec0ee88b8a0abee4054757ad10223450 Mon Sep 17 00:00:00 2001
From: Zalathar <Zalathar@users.noreply.github.com>
Date: Sat, 23 Nov 2024 16:24:23 +1100
Subject: [PATCH] Allow injecting a profiler runtime into `#![no_core]` crates

Now that the profiler runtime is itself `#![no_core]`, it can be a dependency
of other no_core crates, including core.
---
 compiler/rustc_metadata/messages.ftl   | 3 ---
 compiler/rustc_metadata/src/creader.rs | 8 ++------
 compiler/rustc_metadata/src/errors.rs  | 4 ----
 3 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/compiler/rustc_metadata/messages.ftl b/compiler/rustc_metadata/messages.ftl
index d80aa0cc4f4..6d7d88fa8d7 100644
--- a/compiler/rustc_metadata/messages.ftl
+++ b/compiler/rustc_metadata/messages.ftl
@@ -233,9 +233,6 @@ metadata_prev_alloc_error_handler =
 metadata_prev_global_alloc =
     previous global allocator defined here
 
-metadata_profiler_builtins_needs_core =
-    `profiler_builtins` crate (required by compiler options) is not compatible with crate attribute `#![no_core]`
-
 metadata_raw_dylib_no_nul =
     link name must not contain NUL characters if link kind is `raw-dylib`
 
diff --git a/compiler/rustc_metadata/src/creader.rs b/compiler/rustc_metadata/src/creader.rs
index 6c866e72ca3..d1e401fbb75 100644
--- a/compiler/rustc_metadata/src/creader.rs
+++ b/compiler/rustc_metadata/src/creader.rs
@@ -799,7 +799,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
         self.inject_dependency_if(cnum, "a panic runtime", &|data| data.needs_panic_runtime());
     }
 
-    fn inject_profiler_runtime(&mut self, krate: &ast::Crate) {
+    fn inject_profiler_runtime(&mut self) {
         let needs_profiler_runtime =
             self.sess.instrument_coverage() || self.sess.opts.cg.profile_generate.enabled();
         if !needs_profiler_runtime || self.sess.opts.unstable_opts.no_profiler_runtime {
@@ -809,10 +809,6 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
         info!("loading profiler");
 
         let name = Symbol::intern(&self.sess.opts.unstable_opts.profiler_runtime);
-        if name == sym::profiler_builtins && attr::contains_name(&krate.attrs, sym::no_core) {
-            self.dcx().emit_err(errors::ProfilerBuiltinsNeedsCore);
-        }
-
         let Some(cnum) = self.resolve_crate(name, DUMMY_SP, CrateDepKind::Implicit) else {
             return;
         };
@@ -1046,7 +1042,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
 
     pub fn postprocess(&mut self, krate: &ast::Crate) {
         self.inject_forced_externs();
-        self.inject_profiler_runtime(krate);
+        self.inject_profiler_runtime();
         self.inject_allocator_crate(krate);
         self.inject_panic_runtime(krate);
 
diff --git a/compiler/rustc_metadata/src/errors.rs b/compiler/rustc_metadata/src/errors.rs
index 16684ae6f26..b6c5619ec18 100644
--- a/compiler/rustc_metadata/src/errors.rs
+++ b/compiler/rustc_metadata/src/errors.rs
@@ -339,10 +339,6 @@ pub struct NoPanicStrategy {
     pub strategy: PanicStrategy,
 }
 
-#[derive(Diagnostic)]
-#[diag(metadata_profiler_builtins_needs_core)]
-pub struct ProfilerBuiltinsNeedsCore;
-
 #[derive(Diagnostic)]
 #[diag(metadata_not_profiler_runtime)]
 pub struct NotProfilerRuntime {