Bring the version command output in line with other rust tools

crates/rust-analyzer/src/version.rs

@@ -0,0 +1,57 @@
+//! Code for representing rust-analyzer's release version number.
+
+use std::fmt;
+
+/// Information about the git repository where rust-analyzer was built from.
+pub struct CommitInfo {
+    pub short_commit_hash: &'static str,
+    pub commit_hash: &'static str,
+    pub commit_date: &'static str,
+}
+
+/// Cargo's version.
+pub struct VersionInfo {
+    /// rust-analyzer's version, such as "1.57.0", "1.58.0-beta.1", "1.59.0-nightly", etc.
+    pub version: &'static str,
+    /// The release channel we were built for (stable/beta/nightly/dev).
+    ///
+    /// `None` if not built via rustbuild.
+    pub release_channel: Option<&'static str>,
+    /// Information about the Git repository we may have been built from.
+    ///
+    /// `None` if not built from a git repo.
+    pub commit_info: Option<CommitInfo>,
+}
+
+impl fmt::Display for VersionInfo {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.version)?;
+
+        if let Some(ci) = &self.commit_info {
+            write!(f, " ({} {})", ci.short_commit_hash, ci.commit_date)?;
+        };
+        Ok(())
+    }
+}
+
+/// Returns information about cargo's version.
+pub const fn version() -> VersionInfo {
+    let version = match option_env!("CFG_RELEASE") {
+        Some(x) => x,
+        None => "0.0.0",
+    };
+
+    let release_channel = option_env!("CFG_RELEASE_CHANNEL");
+    let commit_info = match (
+        option_env!("RA_COMMIT_SHORT_HASH"),
+        option_env!("RA_COMMIT_HASH"),
+        option_env!("RA_COMMIT_DATE"),
+    ) {
+        (Some(short_commit_hash), Some(commit_hash), Some(commit_date)) => {
+            Some(CommitInfo { short_commit_hash, commit_hash, commit_date })
+        }
+        _ => None,
+    };
+
+    VersionInfo { version, release_channel, commit_info }
+}