Make profiler_runtime Option<String>

Author: bogon-right

Diff for: compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1163,7 +1163,7 @@ fn add_profiler_libraries(sess: &Session, crate_type: CrateType, linker: &mut dy
             || sess.opts.unstable_opts.profile
             || sess.opts.cg.profile_generate.enabled())
         // If user doesn't provide custom profiler runtime, link default llvm profiler.
-        && sess.opts.unstable_opts.profiler_runtime == "profiler_builtins"
+        && sess.opts.unstable_opts.profiler_runtime.is_none()
     {
         link_profiler_runtime(sess, linker);
     }

Diff for: compiler/rustc_interface/src/tests.rs

@@ -770,7 +770,7 @@ fn test_unstable_options_tracking_hash() {
     tracked!(profile, true);
     tracked!(profile_emit, Some(PathBuf::from("abc")));
     tracked!(profile_sample_use, Some(PathBuf::from("abc")));
-    tracked!(profiler_runtime, "abc".to_string());
+    tracked!(profiler_runtime, Some("abc".to_string()));
     tracked!(relax_elf_relocations, Some(true));
     tracked!(relro_level, Some(RelroLevel::Full));
     tracked!(remap_cwd_prefix, Some(PathBuf::from("abc")));

Diff for: compiler/rustc_metadata/src/creader.rs

@@ -764,21 +764,23 @@ impl<'a> CrateLoader<'a> {
             || !(self.sess.instrument_coverage()
                 || self.sess.opts.unstable_opts.profile
                 || self.sess.opts.cg.profile_generate.enabled())
-            || self.sess.opts.unstable_opts.profiler_runtime == "profiler_builtins"
         {
             return;
         }
 
-        info!("loading profiler");
+        // If user doesn't provide custom profiler runtime, skip injection.
+        if let Some(profiler_runtime) = &self.sess.opts.unstable_opts.profiler_runtime {
+            info!("loading profiler: {}", profiler_runtime);
 
-        let name = Symbol::intern(&self.sess.opts.unstable_opts.profiler_runtime);
+            let name = Symbol::intern(profiler_runtime);
 
-        let Some(cnum) = self.resolve_crate(name, DUMMY_SP, CrateDepKind::Implicit) else { return; };
-        let data = self.cstore.get_crate_data(cnum);
+            let Some(cnum) = self.resolve_crate(name, DUMMY_SP, CrateDepKind::Implicit) else { return; };
+            let data = self.cstore.get_crate_data(cnum);
 
-        // Sanity check the loaded crate to ensure it is indeed a profiler runtime
-        if !data.is_profiler_runtime() {
-            self.sess.emit_err(NotProfilerRuntime { crate_name: name });
+            // Sanity check the loaded crate to ensure it is indeed a profiler runtime
+            if !data.is_profiler_runtime() {
+                self.sess.emit_err(NotProfilerRuntime { crate_name: name });
+            }
         }
     }
 

Diff for: compiler/rustc_metadata/src/errors.rs

@@ -601,7 +601,7 @@ pub struct CannotFindCrate {
     pub missing_core: bool,
     pub current_crate: String,
     pub is_nightly_build: bool,
-    pub profiler_runtime: Symbol,
+    pub profiler_runtime: Option<Symbol>,
     pub locator_triple: TargetTriple,
 }
 
@@ -641,7 +641,7 @@ impl IntoDiagnostic<'_> for CannotFindCrate {
             if self.is_nightly_build {
                 diag.help(rustc_errors::fluent::metadata_consider_building_std);
             }
-        } else if self.crate_name == self.profiler_runtime {
+        } else if Some(self.crate_name) == self.profiler_runtime {
             diag.note(rustc_errors::fluent::metadata_compiler_missing_profiler);
         } else if self.crate_name.as_str().starts_with("rustc_") {
             diag.help(rustc_errors::fluent::metadata_install_missing_components);

Diff for: compiler/rustc_metadata/src/locator.rs

@@ -1124,7 +1124,12 @@ impl CrateError {
                             .clone()
                             .unwrap_or("<unknown>".to_string()),
                         is_nightly_build: sess.is_nightly_build(),
-                        profiler_runtime: Symbol::intern(&sess.opts.unstable_opts.profiler_runtime),
+                        profiler_runtime: sess
+                            .opts
+                            .unstable_opts
+                            .profiler_runtime
+                            .as_ref()
+                            .map(|x| Symbol::intern(x)),
                         locator_triple: locator.triple,
                     });
                 }

Diff for: compiler/rustc_session/src/options.rs

@@ -1483,8 +1483,8 @@ options! {
         (default based on relative source path)"),
     profile_sample_use: Option<PathBuf> = (None, parse_opt_pathbuf, [TRACKED],
         "use the given `.prof` file for sampled profile-guided optimization (also known as AutoFDO)"),
-    profiler_runtime: String = (String::from("profiler_builtins"), parse_string, [TRACKED],
-        "name of the profiler runtime crate to automatically inject (default: `profiler_builtins`)"),
+    profiler_runtime: Option<String> = (None, parse_opt_string, [TRACKED],
+        "name of the profiler runtime crate to automatically inject"),
     query_dep_graph: bool = (false, parse_bool, [UNTRACKED],
         "enable queries of the dependency graph for regression testing (default: no)"),
     randomize_layout: bool = (false, parse_bool, [TRACKED],