From e3acd4592019f00ed034b55329f8c9cdd92a59c5 Mon Sep 17 00:00:00 2001
From: Philipp Schuster <phip1611@gmail.com>
Date: Wed, 7 May 2025 08:12:00 +0200
Subject: [PATCH] xtask: simplify env variables

---
 xtask/Cargo.toml  |  2 +-
 xtask/src/opt.rs  |  6 +++---
 xtask/src/qemu.rs | 35 +++++------------------------------
 3 files changed, 9 insertions(+), 34 deletions(-)

diff --git a/xtask/Cargo.toml b/xtask/Cargo.toml
index c9ac855c0..64b8b9db6 100644
--- a/xtask/Cargo.toml
+++ b/xtask/Cargo.toml
@@ -7,7 +7,7 @@ edition.workspace = true
 
 [dependencies]
 anyhow = "1.0.51"
-clap = { version = "4.4.0", default-features = false, features = ["derive", "help", "usage", "std"] }
+clap = { version = "4.4.0", default-features = false, features = ["derive", "help", "usage", "std", "env"] }
 fatfs = { version = "0.3.6", default-features = false, features = ["alloc", "std"] }
 fs-err = "3.0.0"
 heck = "0.5.0"
diff --git a/xtask/src/opt.rs b/xtask/src/opt.rs
index 09350643c..93a3c40f8 100644
--- a/xtask/src/opt.rs
+++ b/xtask/src/opt.rs
@@ -187,15 +187,15 @@ pub struct QemuOpt {
     pub tpm: Option<TpmVersion>,
 
     /// Path of an OVMF code file.
-    #[clap(long, action)]
+    #[clap(long, action, env)]
     pub ovmf_code: Option<PathBuf>,
 
     /// Path of an OVMF vars file.
-    #[clap(long, action)]
+    #[clap(long, action, env)]
     pub ovmf_vars: Option<PathBuf>,
 
     /// Path of an OVMF shell application.
-    #[clap(long, action)]
+    #[clap(long, action, env)]
     pub ovmf_shell: Option<PathBuf>,
 
     /// Run an example instead of the main binary.
diff --git a/xtask/src/qemu.rs b/xtask/src/qemu.rs
index 8f74cee63..e40cdc2ed 100644
--- a/xtask/src/qemu.rs
+++ b/xtask/src/qemu.rs
@@ -26,15 +26,6 @@ const OVMF_PREBUILT_SOURCE: Source = Source::EDK2_STABLE202502_R2;
 /// Directory into which the prebuilts will be download (relative to the repo root).
 const OVMF_PREBUILT_DIR: &str = "target/ovmf";
 
-/// Environment variable for overriding the path of the OVMF code file.
-const ENV_VAR_OVMF_CODE: &str = "OVMF_CODE";
-
-/// Environment variable for overriding the path of the OVMF vars file.
-const ENV_VAR_OVMF_VARS: &str = "OVMF_VARS";
-
-/// Environment variable for overriding the path of the OVMF shell file.
-const ENV_VAR_OVMF_SHELL: &str = "OVMF_SHELL";
-
 impl From<UefiArch> for ovmf_prebuilt::Arch {
     fn from(arch: UefiArch) -> Self {
         match arch {
@@ -47,29 +38,13 @@ impl From<UefiArch> for ovmf_prebuilt::Arch {
 
 /// Get a user-provided path for the given OVMF file type.
 ///
-/// This uses the command-line arg if present, otherwise it falls back to an
-/// environment variable. If neither is present, returns `None`.
+/// This can come from an explicit CLI arg or an environment variable, depending
+/// on how clap received and parsed the value.
 fn get_user_provided_path(file_type: FileType, opt: &QemuOpt) -> Option<PathBuf> {
-    let opt_path;
-    let var_name;
     match file_type {
-        FileType::Code => {
-            opt_path = &opt.ovmf_code;
-            var_name = ENV_VAR_OVMF_CODE;
-        }
-        FileType::Vars => {
-            opt_path = &opt.ovmf_vars;
-            var_name = ENV_VAR_OVMF_VARS;
-        }
-        FileType::Shell => {
-            opt_path = &opt.ovmf_shell;
-            var_name = ENV_VAR_OVMF_SHELL;
-        }
-    }
-    if let Some(path) = opt_path {
-        Some(path.clone())
-    } else {
-        env::var_os(var_name).map(PathBuf::from)
+        FileType::Code => opt.ovmf_code.clone(),
+        FileType::Vars => opt.ovmf_vars.clone(),
+        FileType::Shell => opt.ovmf_shell.clone(),
     }
 }