Only update src/llvm-project submodule if already existing

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

@@ -2509,6 +2509,18 @@ impl Config {
         }
     }
 
+    /// Updates the given submodule only if it's initialized already; nothing happens otherwise.
+    pub(crate) fn update_existing_submodule(&self, submodule: &str) {
+        // Avoid running git when there isn't a git checkout.
+        if !self.submodules() {
+            return;
+        }
+
+        if GitInfo::new(false, Path::new(submodule)).is_managed_git_subrepository() {
+            self.update_submodule(submodule);
+        }
+    }
+
     /// Given a path to the directory of a submodule, update it.
     ///
     /// `relative_path` should be relative to the root of the git repository, not an absolute path.
@@ -2738,7 +2750,7 @@ impl Config {
                 return false;
             }
 
-            self.update_submodule("src/llvm-project");
+            self.update_existing_submodule("src/llvm-project");
 
             // Check for untracked changes in `src/llvm-project`.
             let has_changes = self

src/bootstrap/src/lib.rs

@@ -542,14 +542,7 @@ impl Build {
 
     /// Updates the given submodule only if it's initialized already; nothing happens otherwise.
     pub fn update_existing_submodule(&self, submodule: &str) {
-        // Avoid running git when there isn't a git checkout.
-        if !self.config.submodules() {
-            return;
-        }
-
-        if GitInfo::new(false, Path::new(submodule)).is_managed_git_subrepository() {
-            self.config.update_submodule(submodule);
-        }
+        self.config.update_existing_submodule(submodule)
     }
 
     /// Executes the entire build, as configured by the flags and configuration.