WIP: SHA check

Author: Kobzol

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

@@ -15,7 +15,9 @@ use std::{cmp, env, fs};
 
 use build_helper::ci::CiEnv;
 use build_helper::exit;
-use build_helper::git::{GitConfig, PathFreshness, check_path_modifications, output_result};
+use build_helper::git::{
+    GitConfig, PathFreshness, check_path_modifications, get_closest_merge_commit, output_result,
+};
 use serde::{Deserialize, Deserializer};
 use serde_derive::Deserialize;
 #[cfg(feature = "tracing")]
@@ -3020,41 +3022,70 @@ impl Config {
         asserts: bool,
     ) -> bool {
         let download_ci_llvm = download_ci_llvm.unwrap_or(StringOrBool::Bool(true));
-
-        let if_unchanged = || {
-            if self.rust_info.is_from_tarball() {
-                // Git is needed for running "if-unchanged" logic.
-                println!("ERROR: 'if-unchanged' is only compatible with Git managed sources.");
-                crate::exit!(1);
-            }
-
-            // Fetching the LLVM submodule is unnecessary for self-tests.
-            #[cfg(not(test))]
-            self.update_submodule("src/llvm-project");
-
-            // Check for untracked changes in `src/llvm-project`.
-            let has_changes = self.has_changes_from_upstream(&["src/llvm-project"]);
-
-            // Return false if there are untracked changes, otherwise check if CI LLVM is available.
-            if has_changes { false } else { llvm::is_ci_llvm_available(self, asserts) }
-        };
-
-        match download_ci_llvm {
-            StringOrBool::Bool(b) => {
-                if !b && self.download_rustc_commit.is_some() {
-                    panic!(
-                        "`llvm.download-ci-llvm` cannot be set to `false` if `rust.download-rustc` is set to `true` or `if-unchanged`."
-                    );
-                }
-
-                // If download-ci-llvm=true we also want to check that CI llvm is available
-                b && llvm::is_ci_llvm_available(self, asserts)
-            }
-            StringOrBool::String(s) if s == "if-unchanged" => if_unchanged(),
-            StringOrBool::String(other) => {
-                panic!("unrecognized option for download-ci-llvm: {:?}", other)
-            }
-        }
+        let freshness = self.check_modifications(&[
+            "src/llvm-project",
+            "src/bootstrap/download-ci-llvm-stamp",
+            "src/version",
+        ]);
+        let sha = get_closest_merge_commit(
+            Some(&self.src),
+            &self.git_config(),
+            &[
+                self.src.join("src/llvm-project"),
+                self.src.join("src/bootstrap/download-ci-llvm-stamp"),
+                // the LLVM shared object file is named `LLVM-12-rust-{version}-nightly`
+                self.src.join("src/version"),
+            ],
+        )
+        .unwrap();
+        let head = String::from_utf8(
+            Command::new("git")
+                .current_dir(&self.src)
+                .arg("rev-parse")
+                .arg("HEAD")
+                .output()
+                .unwrap()
+                .stdout,
+        )
+        .unwrap()
+        .trim()
+        .to_string();
+        panic!("LLVM FRESHNESS: {freshness:?}\nOld git SHA: {sha}\nHEAD: {head}");
+        //
+        // let if_unchanged = || {
+        //     if self.rust_info.is_from_tarball() {
+        //         // Git is needed for running "if-unchanged" logic.
+        //         println!("ERROR: 'if-unchanged' is only compatible with Git managed sources.");
+        //         crate::exit!(1);
+        //     }
+        //
+        //     // Fetching the LLVM submodule is unnecessary for self-tests.
+        //     #[cfg(not(test))]
+        //     self.update_submodule("src/llvm-project");
+        //
+        //     // Check for untracked changes in `src/llvm-project`.
+        //     let has_changes = self.has_changes_from_upstream(&["src/llvm-project"]);
+        //
+        //     // Return false if there are untracked changes, otherwise check if CI LLVM is available.
+        //     if has_changes { false } else { llvm::is_ci_llvm_available(self, asserts) }
+        // };
+        //
+        // match download_ci_llvm {
+        //     StringOrBool::Bool(b) => {
+        //         if !b && self.download_rustc_commit.is_some() {
+        //             panic!(
+        //                 "`llvm.download-ci-llvm` cannot be set to `false` if `rust.download-rustc` is set to `true` or `if-unchanged`."
+        //             );
+        //         }
+        //
+        //         // If download-ci-llvm=true we also want to check that CI llvm is available
+        //         b && llvm::is_ci_llvm_available(self, asserts)
+        //     }
+        //     StringOrBool::String(s) if s == "if-unchanged" => if_unchanged(),
+        //     StringOrBool::String(other) => {
+        //         panic!("unrecognized option for download-ci-llvm: {:?}", other)
+        //     }
+        // }
     }
 
     /// Returns true if any of the `paths` have been modified locally.

src/bootstrap/src/lib.rs

@@ -1,3 +1,4 @@
+#![allow(unused)]
 //! Implementation of bootstrap, the Rust build system.
 //!
 //! This module, and its descendants, are the implementation of the Rust build

src/build_helper/src/git.rs

@@ -1,7 +1,7 @@
 #[cfg(test)]
 mod tests;
 
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
 
 use crate::ci::CiEnv;