test,xtask: Replace lazy_static with OnceCell

This doesn't affect MSRV because this is testing code.

test/integration-test/Cargo.toml

@@ -14,7 +14,6 @@ env_logger = "0.10"
 futures-core = "0.3"
 inventory = "0.3"
 integration-test-macros = { path = "../integration-test-macros" }
-lazy_static = "1"
 libc = { version = "0.2.105" }
 log = "0.4"
 object = { version = "0.31", default-features = false, features = ["std", "read_core", "elf"] }

test/integration-test/src/tests/mod.rs

@@ -1,8 +1,7 @@
 use anyhow::bail;
-use lazy_static::lazy_static;
 use libc::{uname, utsname};
 use regex::Regex;
-use std::{ffi::CStr, mem};
+use std::{cell::OnceCell, ffi::CStr, mem};
 
 pub mod bpf_probe_read;
 pub mod btf_relocations;
@@ -22,15 +21,15 @@ pub struct IntegrationTest {
 }
 
 pub(crate) fn kernel_version() -> anyhow::Result<(u8, u8, u8)> {
-    lazy_static! {
-        static ref RE: Regex = Regex::new(r"^([0-9]+)\.([0-9]+)\.([0-9]+)").unwrap();
-    }
+    static mut RE: OnceCell<Regex> = OnceCell::new();
+    let re =
+        unsafe { &mut RE }.get_or_init(|| Regex::new(r"^([0-9]+)\.([0-9]+)\.([0-9]+)").unwrap());
     let mut data: utsname = unsafe { mem::zeroed() };
     let ret = unsafe { uname(&mut data) };
     assert!(ret >= 0, "libc::uname failed.");
     let release_cstr = unsafe { CStr::from_ptr(data.release.as_ptr()) };
     let release = release_cstr.to_string_lossy();
-    if let Some(caps) = RE.captures(&release) {
+    if let Some(caps) = re.captures(&release) {
         let major = caps.get(1).unwrap().as_str().parse().unwrap();
         let minor = caps.get(2).unwrap().as_str().parse().unwrap();
         let patch = caps.get(3).unwrap().as_str().parse().unwrap();

xtask/Cargo.toml

@@ -12,5 +12,4 @@ syn = "2"
 quote = "1"
 proc-macro2 = "1"
 indoc = "2.0"
-lazy_static = "1"
 serde_json = "1"

xtask/src/build_ebpf.rs

@@ -7,7 +7,7 @@ use std::{
 use anyhow::{bail, Context};
 use clap::Parser;
 
-use crate::utils::WORKSPACE_ROOT;
+use crate::utils::workspace_root;
 
 #[derive(Debug, Copy, Clone)]
 pub enum Architecture {
@@ -52,7 +52,7 @@ pub fn build_ebpf(opts: BuildEbpfOptions) -> anyhow::Result<()> {
 }
 
 fn build_rust_ebpf(opts: &BuildEbpfOptions) -> anyhow::Result<()> {
-    let mut dir = PathBuf::from(WORKSPACE_ROOT.to_string());
+    let mut dir = PathBuf::from(workspace_root());
     dir.push("test/integration-ebpf");
 
     let target = format!("--target={}", opts.target);
@@ -88,10 +88,10 @@ fn get_libbpf_headers<P: AsRef<Path>>(libbpf_dir: P, include_path: P) -> anyhow:
 }
 
 fn build_c_ebpf(opts: &BuildEbpfOptions) -> anyhow::Result<()> {
-    let mut src = PathBuf::from(WORKSPACE_ROOT.to_string());
+    let mut src = PathBuf::from(workspace_root());
     src.push("test/integration-ebpf/src/bpf");
 
-    let mut out_path = PathBuf::from(WORKSPACE_ROOT.to_string());
+    let mut out_path = PathBuf::from(workspace_root());
     out_path.push("target");
     out_path.push(opts.target.to_string());
     out_path.push("release");

xtask/src/utils.rs

@@ -1,17 +1,15 @@
-use lazy_static::lazy_static;
 use serde_json::Value;
-use std::process::Command;
+use std::{cell::OnceCell, process::Command};
 
-lazy_static! {
-    pub static ref WORKSPACE_ROOT: String = workspace_root();
-}
-
-fn workspace_root() -> String {
-    let output = Command::new("cargo").arg("metadata").output().unwrap();
-    if !output.status.success() {
-        panic!("unable to run cargo metadata")
-    }
-    let stdout = String::from_utf8(output.stdout).unwrap();
-    let v: Value = serde_json::from_str(&stdout).unwrap();
-    v["workspace_root"].as_str().unwrap().to_string()
+pub fn workspace_root() -> &'static str {
+    static mut WORKSPACE_ROOT: OnceCell<String> = OnceCell::new();
+    unsafe { &mut WORKSPACE_ROOT }.get_or_init(|| {
+        let output = Command::new("cargo").arg("metadata").output().unwrap();
+        if !output.status.success() {
+            panic!("unable to run cargo metadata")
+        }
+        let stdout = String::from_utf8(output.stdout).unwrap();
+        let v: Value = serde_json::from_str(&stdout).unwrap();
+        v["workspace_root"].as_str().unwrap().to_string()
+    })
 }