Fix x check --stage 1 when download-ci-llvm=false

src/bootstrap/check.rs

@@ -237,7 +237,7 @@ impl Step for Rustc {
             target,
             cargo_subcommand(builder.kind),
         );
-        rustc_cargo(builder, &mut cargo, target);
+        rustc_cargo(builder, &mut cargo, target, compiler.stage);
 
         // For ./x.py clippy, don't run with --all-targets because
         // linting tests and benchmarks can produce very noisy results
@@ -315,7 +315,7 @@ impl Step for CodegenBackend {
         cargo
             .arg("--manifest-path")
             .arg(builder.src.join(format!("compiler/rustc_codegen_{}/Cargo.toml", backend)));
-        rustc_cargo_env(builder, &mut cargo, target);
+        rustc_cargo_env(builder, &mut cargo, target, compiler.stage);
 
         let msg = if compiler.host == target {
             format!("Checking stage{} {} artifacts ({target})", builder.top_stage, backend)

src/bootstrap/compile.rs

@@ -696,7 +696,7 @@ impl Step for Rustc {
         ));
 
         let mut cargo = builder.cargo(compiler, Mode::Rustc, SourceType::InTree, target, "build");
-        rustc_cargo(builder, &mut cargo, target);
+        rustc_cargo(builder, &mut cargo, target, compiler.stage);
 
         if builder.config.rust_profile_use.is_some()
             && builder.config.rust_profile_generate.is_some()
@@ -813,16 +813,21 @@ impl Step for Rustc {
     }
 }
 
-pub fn rustc_cargo(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelection) {
+pub fn rustc_cargo(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelection, stage: u32) {
     cargo
         .arg("--features")
         .arg(builder.rustc_features(builder.kind))
         .arg("--manifest-path")
         .arg(builder.src.join("compiler/rustc/Cargo.toml"));
-    rustc_cargo_env(builder, cargo, target);
+    rustc_cargo_env(builder, cargo, target, stage);
 }
 
-pub fn rustc_cargo_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelection) {
+pub fn rustc_cargo_env(
+    builder: &Builder<'_>,
+    cargo: &mut Cargo,
+    target: TargetSelection,
+    stage: u32,
+) {
     // Set some configuration variables picked up by build scripts and
     // the compiler alike
     cargo
@@ -867,16 +872,18 @@ pub fn rustc_cargo_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetS
         cargo.env("RUSTC_VERIFY_LLVM_IR", "1");
     }
 
-    //
     // Note that this is disabled if LLVM itself is disabled or we're in a check
     // build. If we are in a check build we still go ahead here presuming we've
     // detected that LLVM is already built and good to go which helps prevent
     // busting caches (e.g. like #71152).
-    if builder.config.llvm_enabled()
-        && (builder.kind != Kind::Check
-            || crate::llvm::prebuilt_llvm_config(builder, target).is_ok())
-    {
-        rustc_llvm_env(builder, cargo, target)
+    if builder.config.llvm_enabled() {
+        let building_is_expensive = crate::llvm::prebuilt_llvm_config(builder, target).is_err();
+        // `top_stage == stage` might be false for `check --stage 1`, if we are building the stage 1 compiler
+        let can_skip_build = builder.kind == Kind::Check && builder.top_stage == stage;
+        let should_skip_build = building_is_expensive && can_skip_build;
+        if !should_skip_build {
+            rustc_llvm_env(builder, cargo, target)
+        }
     }
 }
 
@@ -933,13 +940,8 @@ fn rustc_llvm_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelect
         && !target.contains("apple")
         && !target.contains("solaris")
     {
-        let file = compiler_file(
-            builder,
-            builder.cxx(target).unwrap(),
-            target,
-            CLang::Cxx,
-            "libstdc++.a",
-        );
+        let file =
+            compiler_file(builder, builder.cxx(target).unwrap(), target, CLang::Cxx, "libstdc++.a");
         cargo.env("LLVM_STATIC_STDCPP", file);
     }
     if builder.llvm_link_shared() {
@@ -1054,7 +1056,7 @@ impl Step for CodegenBackend {
         cargo
             .arg("--manifest-path")
             .arg(builder.src.join(format!("compiler/rustc_codegen_{}/Cargo.toml", backend)));
-        rustc_cargo_env(builder, &mut cargo, target);
+        rustc_cargo_env(builder, &mut cargo, target, compiler.stage);
 
         let tmp_stamp = out_dir.join(".tmp.stamp");
 

src/bootstrap/doc.rs

@@ -696,7 +696,7 @@ impl Step for Rustc {
         cargo.rustdocflag("-Znormalize-docs");
         cargo.rustdocflag("--show-type-layout");
         cargo.rustdocflag("--generate-link-to-definition");
-        compile::rustc_cargo(builder, &mut cargo, target);
+        compile::rustc_cargo(builder, &mut cargo, target, compiler.stage);
         cargo.arg("-Zunstable-options");
         cargo.arg("-Zskip-rustdoc-fingerprint");
 

src/bootstrap/test.rs

@@ -2143,7 +2143,7 @@ impl Step for Crate {
                 compile::std_cargo(builder, target, compiler.stage, &mut cargo);
             }
             Mode::Rustc => {
-                compile::rustc_cargo(builder, &mut cargo, target);
+                compile::rustc_cargo(builder, &mut cargo, target, compiler.stage);
             }
             _ => panic!("can only test libraries"),
         };