release: Use version string from git if available

If the SVSM is built from the git repository, get the version string
via 'git describe' to have a more acurate version identifier. The git
version allows to identify from which commit the code was built.

Signed-off-by: Joerg Roedel <[email protected]>

.gitignore

@@ -9,6 +9,7 @@ verus*.log
 gen_meta
 stage1/stage1
 stage1/stage1-test
+release/src/git_version.rs
 print-meta
 cbit
 .idea/

release/build.rs

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: MIT
+//
+// Copyright (c) 2025 SUSE LLC
+//
+// Author: Joerg Roedel <[email protected]>
+
+use std::fs::OpenOptions;
+use std::io::prelude::*;
+use std::process::Command;
+use std::string::String;
+
+fn git_version() -> Result<String, ()> {
+    let output = Command::new("git")
+        .args(["describe", "--always", "--dirty=+"])
+        .output()
+        .map_err(|_| ())?;
+    if !output.status.success() {
+        return Err(());
+    }
+
+    let stdout = String::from_utf8(output.stdout).unwrap();
+    let mut lines = stdout.lines();
+    let first_line = lines.next().unwrap().trim();
+
+    Ok(String::from(first_line))
+}
+
+fn write_version(version: String) {
+    let mut file = OpenOptions::new()
+        .create(true)
+        .write(true)
+        .truncate(true)
+        .open("src/git_version.rs")
+        .unwrap();
+    writeln!(&mut file, "// SPDX-License-Identifier: MIT\n//").unwrap();
+    writeln!(
+        &mut file,
+        "// This file is automatically generated - Any changes will be overwritten\n//\n"
+    )
+    .unwrap();
+    writeln!(&mut file, "pub const GIT_VERSION: &str = \"{}\";", version).unwrap();
+}
+
+fn main() {
+    write_version(git_version().unwrap_or_default());
+}

release/src/lib.rs

@@ -6,7 +6,10 @@
 
 #![no_std]
 
+mod git_version;
+
 use core::fmt;
+use git_version::GIT_VERSION;
 
 #[allow(dead_code)]
 #[derive(Debug)]
@@ -28,15 +31,20 @@ pub struct SvsmVersion {
 
 impl fmt::Display for SvsmVersion {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.release_type {
-            ReleaseType::Development => {
-                write!(f, "{}.{:#02}-devel", self.year, self.month)
-            }
-            ReleaseType::Candidate(counter) => {
-                write!(f, "{}.{:#02}-rc{}", self.year, self.month, counter)
-            }
-            ReleaseType::Stable(counter) => {
-                write!(f, "{}.{:#02}.{}", self.year, self.month, counter)
+        #[allow(clippy::const_is_empty)]
+        if !GIT_VERSION.is_empty() {
+            write!(f, "{}", GIT_VERSION)
+        } else {
+            match self.release_type {
+                ReleaseType::Development => {
+                    write!(f, "{}.{:#02}-devel", self.year, self.month)
+                }
+                ReleaseType::Candidate(counter) => {
+                    write!(f, "{}.{:#02}-rc{}", self.year, self.month, counter)
+                }
+                ReleaseType::Stable(counter) => {
+                    write!(f, "{}.{:#02}.{}", self.year, self.month, counter)
+                }
             }
         }
     }