Auto merge of #134650 - onur-ozkan:clean-up-fixmes, r=Kobzol

Clean up some FIXME notes on bootstrap

Fixing and removing some FIXME notes.

src/bootstrap/src/core/config/config.rs

@@ -1154,7 +1154,6 @@ define_config! {
         debuginfo_level_tests: Option<DebuginfoLevel> = "debuginfo-level-tests",
         backtrace: Option<bool> = "backtrace",
         incremental: Option<bool> = "incremental",
-        parallel_compiler: Option<bool> = "parallel-compiler",
         default_linker: Option<String> = "default-linker",
         channel: Option<String> = "channel",
         description: Option<String> = "description",
@@ -1755,7 +1754,6 @@ impl Config {
                 debuginfo_level_tests: debuginfo_level_tests_toml,
                 backtrace,
                 incremental,
-                parallel_compiler,
                 randomize_layout,
                 default_linker,
                 channel: _, // already handled above
@@ -1865,13 +1863,6 @@ impl Config {
             config.rust_randomize_layout = randomize_layout.unwrap_or_default();
             config.llvm_tools_enabled = llvm_tools.unwrap_or(true);
 
-            // FIXME: Remove this option at the end of 2024.
-            if parallel_compiler.is_some() {
-                println!(
-                    "WARNING: The `rust.parallel-compiler` option is deprecated and does nothing. The parallel compiler (with one thread) is now the default"
-                );
-            }
-
             config.llvm_enzyme =
                 llvm_enzyme.unwrap_or(config.channel == "dev" || config.channel == "nightly");
             config.rustc_default_linker = default_linker;
@@ -3213,7 +3204,6 @@ fn check_incompatible_options_for_ci_rustc(
         debuginfo_level_tools: _,
         debuginfo_level_tests: _,
         backtrace: _,
-        parallel_compiler: _,
         musl_root: _,
         verbose_tests: _,
         optimize_tests: _,

src/bootstrap/src/core/download.rs

@@ -197,8 +197,7 @@ impl Config {
         if !path_is_dylib(fname) {
             // Finally, set the correct .interp for binaries
             let dynamic_linker_path = nix_deps_dir.join("nix-support/dynamic-linker");
-            // FIXME: can we support utf8 here? `args` doesn't accept Vec<u8>, only OsString ...
-            let dynamic_linker = t!(String::from_utf8(t!(fs::read(dynamic_linker_path))));
+            let dynamic_linker = t!(fs::read_to_string(dynamic_linker_path));
             patchelf.args(["--set-interpreter", dynamic_linker.trim_end()]);
         }
 

src/bootstrap/src/lib.rs

@@ -635,11 +635,12 @@ impl Build {
         if self.config.backtrace {
             features.insert("backtrace");
         }
+
         if self.config.profiler_enabled(target) {
             features.insert("profiler");
         }
-        // Generate memcpy, etc.  FIXME: Remove this once compiler-builtins
-        // automatically detects this target.
+
+        // If zkvm target, generate memcpy, etc.
         if target.contains("zkvm") {
             features.insert("compiler-builtins-mem");
         }

src/bootstrap/src/utils/change_tracker.rs

@@ -320,4 +320,9 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
         severity: ChangeSeverity::Warning,
         summary: "compiletest now takes `--no-capture` instead of `--nocapture`; bootstrap now accepts `--no-capture` as an argument to test commands directly",
     },
+    ChangeInfo {
+        change_id: 134650,
+        severity: ChangeSeverity::Warning,
+        summary: "Removed `rust.parallel-compiler` as it was deprecated in #132282 long time ago.",
+    },
 ];