fix: build script generates dead code warnings if versioning data is not used

engine/build.rs

@@ -1,18 +1,28 @@
-use std::process::Command;
-use std::env;
-use std::path::Path;
-use std::fs::OpenOptions;
-use std::io::Write;
 use build_print::*;
 use cargo_lock::Lockfile;
+use std::env;
+use std::fs::OpenOptions;
+use std::io::Write;
+use std::path::Path;
+use std::process::Command;
 
 fn get_git_info() -> String {
-    match Command::new("git").arg("describe").arg("--always").arg("--dirty").output() {
+    match Command::new("git")
+        .arg("describe")
+        .arg("--always")
+        .arg("--dirty")
+        .output()
+    {
         Ok(output) if output.status.success() => {
             String::from_utf8_lossy(&output.stdout).trim().to_string()
         }
         _ => {
-            match Command::new("git").arg("rev-parse").arg("--abbrev-ref").arg("HEAD").output() {
+            match Command::new("git")
+                .arg("rev-parse")
+                .arg("--abbrev-ref")
+                .arg("HEAD")
+                .output()
+            {
                 Ok(output) if output.status.success() => {
                     let head = String::from_utf8_lossy(&output.stdout);
                     let head = head.trim();
@@ -28,7 +38,7 @@ fn get_git_info() -> String {
         }
     }
 }
-
+static ALLOW_DEAD_CODE: &str = "#[allow(dead_code)]\n";
 fn main() {
     if let Err(e) = built::write_built_file() {
         panic!("{e}");
@@ -36,13 +46,15 @@ fn main() {
     let out_dir = env::var("OUT_DIR").unwrap();
     let dest_path = Path::new(&out_dir).join("built.rs");
     let proj_root = env!("CARGO_MANIFEST_DIR").to_string();
-    let tmp = format!("{}/../Cargo.lock",proj_root);
+    let tmp = format!("{}/../Cargo.lock", proj_root);
     let lockfile_path = Path::new(&tmp).canonicalize().expect("INvalid");
 
-
     let cargo_version = match Command::new("cargo").arg("--version").output() {
         Ok(output) if output.status.success() => {
-            String::from_utf8_lossy(&output.stdout).trim().to_string()
+            let mut version = String::new();
+            version.push_str(ALLOW_DEAD_CODE);
+            version.push_str(&String::from_utf8_lossy(&output.stdout).trim().to_string());
+            version
         }
         _ => "unknown".to_string(),
     };
@@ -50,7 +62,10 @@ fn main() {
 
     let rustc_version = match Command::new("rustc").arg("--version").output() {
         Ok(output) if output.status.success() => {
-            String::from_utf8_lossy(&output.stdout).trim().to_string()
+            let mut version = String::new();
+            version.push_str(ALLOW_DEAD_CODE);
+            version.push_str(&String::from_utf8_lossy(&output.stdout).trim().to_string());
+            version
         }
         _ => "unknown".to_string(),
     };
@@ -67,7 +82,13 @@ fn main() {
         }
     };
 
-    writeln!(built_rs, "pub const GIT_COMMIT_HASH: &str = \"{}\";", git_info).unwrap();
+    writeln!(
+        built_rs,
+        "{}pub static GIT_COMMIT_HASH: &str = \"{}\";",
+        ALLOW_DEAD_CODE,
+        git_info
+    )
+    .unwrap();
 
     match Lockfile::load(lockfile_path) {
         Ok(lockfile) => {
@@ -75,16 +96,17 @@ fn main() {
 
             for package in lockfile.packages {
                 let name = package.name.as_str();
-                    if dependencies_to_track.contains(&name) {
+                if dependencies_to_track.contains(&name) {
-                        let version = package.version.to_string();
+                    let version = package.version.to_string();
-                        writeln!(
+                    writeln!(
-                            built_rs,
+                        built_rs,
-                            "pub const {}_VERSION: &str = \"{}\";",
+                        "{}pub static {}_VERSION: &str = \"{}\";",
-                            name.to_uppercase().replace('-', "_"),
+                        ALLOW_DEAD_CODE,
-                            version
+                        name.to_uppercase().replace('-', "_"),
-                        )
+                        version
-                        .unwrap();
+                    )
-                    }
+                    .unwrap();
+                }
             }
         }
         Err(e) => {
@@ -92,7 +114,6 @@ fn main() {
         }
     }
 
-
     std::println!("cargo:rerun-if-changed=Cargo.lock");
     std::println!("cargo:rerun-if-changed=.git/HEAD");
     std::println!("cargo:rerun-if-changed=.git/index");