rustc_tools_util: rerun when git commit changes

Cargo.toml

@@ -23,7 +23,7 @@ path = "src/driver.rs"
 [dependencies]
 clippy_config = { path = "clippy_config" }
 clippy_lints = { path = "clippy_lints" }
-rustc_tools_util = "0.3.0"
+rustc_tools_util = "0.4.0"
 tempfile = { version = "3.3", optional = true }
 termize = "0.1"
 color-print = "0.3.4"
@@ -50,7 +50,7 @@ parking_lot = "0.12"
 tokio = { version = "1", features = ["io-util"] }
 
 [build-dependencies]
-rustc_tools_util = "0.3.0"
+rustc_tools_util = "0.4.0"
 
 [features]
 integration = ["tempfile"]

rustc_tools_util/CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog
 
+## Version 0.4.0
+
+* The commit hashes are now always 10 characters long [#13222](https://github.com/rust-lang/rust-clippy/pull/13222)
+* `get_commit_date` and `get_commit_hash` now return `None` if the `git` command fails instead of `Some("")`
+  [#13217](https://github.com/rust-lang/rust-clippy/pull/13217)
+* `setup_version_info` will now re-run when the git commit changes
+  [#13329](https://github.com/rust-lang/rust-clippy/pull/13329)
+* New `rerun_if_git_changes` function was added [#13329](https://github.com/rust-lang/rust-clippy/pull/13329)
+
 ## Version 0.3.0
 
 * Added `setup_version_info!();` macro for automated scripts.

rustc_tools_util/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rustc_tools_util"
-version = "0.3.0"
+version = "0.4.0"
 description = "small helper to generate version information for git packages"
 repository = "https://github.com/rust-lang/rust-clippy"
 readme = "README.md"

rustc_tools_util/README.md

@@ -13,10 +13,10 @@ build = "build.rs"
 List rustc_tools_util as regular AND build dependency.
 ````toml
 [dependencies]
-rustc_tools_util = "0.3.0"
+rustc_tools_util = "0.4.0"
 
 [build-dependencies]
-rustc_tools_util = "0.3.0"
+rustc_tools_util = "0.4.0"
 ````
 
 In `build.rs`, generate the data in your `main()`

rustc_tools_util/src/lib.rs

@@ -1,3 +1,5 @@
+use std::path::PathBuf;
+use std::process::Command;
 use std::str;
 
 /// This macro creates the version string during compilation from the
@@ -32,6 +34,7 @@ macro_rules! get_version_info {
 #[macro_export]
 macro_rules! setup_version_info {
     () => {{
+        let _ = $crate::rerun_if_git_changes();
         println!(
             "cargo:rustc-env=GIT_HASH={}",
             $crate::get_commit_hash().unwrap_or_default()
@@ -100,24 +103,52 @@ impl std::fmt::Debug for VersionInfo {
 }
 
 #[must_use]
-pub fn get_commit_hash() -> Option<String> {
-    let output = std::process::Command::new("git")
-        .args(["rev-parse", "HEAD"])
-        .output()
-        .ok()?;
+fn get_output(cmd: &str, args: &[&str]) -> Option<String> {
+    let output = Command::new(cmd).args(args).output().ok()?;
     let mut stdout = output.status.success().then_some(output.stdout)?;
-    stdout.truncate(10);
+    // Remove trailing newlines.
+    while stdout.last().copied() == Some(b'\n') {
+        stdout.pop();
+    }
     String::from_utf8(stdout).ok()
 }
 
+#[must_use]
+pub fn rerun_if_git_changes() -> Option<()> {
+    // Make sure we get rerun when the git commit changes.
+    // We want to watch two files: HEAD, which tracks which branch we are on,
+    // and the file for that branch that tracks which commit is is on.
+
+    // First, find the `HEAD` file. This should work even with worktrees.
+    let git_head_file = PathBuf::from(get_output("git", &["rev-parse", "--git-path", "HEAD"])?);
+    if git_head_file.exists() {
+        println!("cargo::rerun-if-changed={}", git_head_file.display());
+    }
+
+    // Determine the name of the current ref.
+    // This will quit if HEAD is detached.
+    let git_head_ref = get_output("git", &["symbolic-ref", "-q", "HEAD"])?;
+    // Ask git where this ref is stored.
+    let git_head_ref_file = PathBuf::from(get_output("git", &["rev-parse", "--git-path", &git_head_ref])?);
+    // If this ref is packed, the file does not exist. However, the checked-out branch is never (?)
+    // packed, so we should always be able to find this file.
+    if git_head_ref_file.exists() {
+        println!("cargo::rerun-if-changed={}", git_head_ref_file.display());
+    }
+
+    Some(())
+}
+
+#[must_use]
+pub fn get_commit_hash() -> Option<String> {
+    let mut stdout = get_output("git", &["rev-parse", "HEAD"])?;
+    stdout.truncate(10);
+    Some(stdout)
+}
+
 #[must_use]
 pub fn get_commit_date() -> Option<String> {
-    let output = std::process::Command::new("git")
-        .args(["log", "-1", "--date=short", "--pretty=format:%cd"])
-        .output()
-        .ok()?;
-    let stdout = output.status.success().then_some(output.stdout)?;
-    String::from_utf8(stdout).ok()
+    get_output("git", &["log", "-1", "--date=short", "--pretty=format:%cd"])
 }
 
 #[must_use]
@@ -127,15 +158,11 @@ pub fn get_channel() -> String {
     }
 
     // if that failed, try to ask rustc -V, do some parsing and find out
-    if let Ok(output) = std::process::Command::new("rustc").arg("-V").output() {
-        if output.status.success() {
-            if let Ok(rustc_output) = str::from_utf8(&output.stdout) {
-                if rustc_output.contains("beta") {
-                    return String::from("beta");
-                } else if rustc_output.contains("stable") {
-                    return String::from("stable");
-                }
-            }
+    if let Some(rustc_output) = get_output("rustc", &["-V"]) {
+        if rustc_output.contains("beta") {
+            return String::from("beta");
+        } else if rustc_output.contains("stable") {
+            return String::from("stable");
         }
     }
 
@@ -151,7 +178,7 @@ mod test {
     fn test_struct_local() {
         let vi = get_version_info!();
         assert_eq!(vi.major, 0);
-        assert_eq!(vi.minor, 3);
+        assert_eq!(vi.minor, 4);
         assert_eq!(vi.patch, 0);
         assert_eq!(vi.crate_name, "rustc_tools_util");
         // hard to make positive tests for these since they will always change
@@ -162,7 +189,7 @@ mod test {
     #[test]
     fn test_display_local() {
         let vi = get_version_info!();
-        assert_eq!(vi.to_string(), "rustc_tools_util 0.3.0");
+        assert_eq!(vi.to_string(), "rustc_tools_util 0.4.0");
     }
 
     #[test]
@@ -171,7 +198,7 @@ mod test {
         let s = format!("{vi:?}");
         assert_eq!(
             s,
-            "VersionInfo { crate_name: \"rustc_tools_util\", major: 0, minor: 3, patch: 0 }"
+            "VersionInfo { crate_name: \"rustc_tools_util\", major: 0, minor: 4, patch: 0 }"
         );
     }
 }