From 54e9ed9932a479e7d4548306113a6d98a8d6ba15 Mon Sep 17 00:00:00 2001
From: Wei Liu <liuwe@microsoft.com>
Date: Thu, 12 Jan 2023 15:53:51 +0000
Subject: [PATCH] vhost_user_blk: switch to argh

Signed-off-by: Wei Liu <liuwe@microsoft.com>
---
 Cargo.lock                   |  2 +-
 vhost_user_block/Cargo.toml  |  2 +-
 vhost_user_block/src/lib.rs  |  5 -----
 vhost_user_block/src/main.rs | 27 ++++++++++++---------------
 4 files changed, 14 insertions(+), 22 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 612d9f938..27db7a7f8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1417,8 +1417,8 @@ dependencies = [
 name = "vhost_user_block"
 version = "0.1.0"
 dependencies = [
+ "argh",
  "block_util",
- "clap",
  "env_logger",
  "epoll",
  "libc",
diff --git a/vhost_user_block/Cargo.toml b/vhost_user_block/Cargo.toml
index 0d1ab834a..32546e7ce 100644
--- a/vhost_user_block/Cargo.toml
+++ b/vhost_user_block/Cargo.toml
@@ -5,8 +5,8 @@ authors = ["The Cloud Hypervisor Authors"]
 edition = "2021"
 
 [dependencies]
+argh = "0.1.9"
 block_util = { path = "../block_util" }
-clap = { version = "4.0.32", features = ["wrap_help"] }
 env_logger = "0.10.0"
 epoll = "4.3.1"
 libc = "0.2.139"
diff --git a/vhost_user_block/src/lib.rs b/vhost_user_block/src/lib.rs
index a5286e03d..738b681dc 100644
--- a/vhost_user_block/src/lib.rs
+++ b/vhost_user_block/src/lib.rs
@@ -70,11 +70,6 @@ enum Error {
     SocketParameterMissing,
 }
 
-pub const SYNTAX: &str = "vhost-user-block backend parameters \
- \"path=<image_path>,socket=<socket_path>,num_queues=<number_of_queues>,\
- queue_size=<size_of_each_queue>,readonly=true|false,direct=true|false,\
- poll_queue=true|false\"";
-
 impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "vhost_user_block_error: {self:?}")
diff --git a/vhost_user_block/src/main.rs b/vhost_user_block/src/main.rs
index 2d7d68556..2e3885683 100644
--- a/vhost_user_block/src/main.rs
+++ b/vhost_user_block/src/main.rs
@@ -10,25 +10,22 @@
 
 extern crate vhost_user_block;
 
-use clap::{Arg, Command};
+use argh::FromArgs;
 use vhost_user_block::start_block_backend;
 
+#[derive(FromArgs)]
+/// Launch a vhost-user-blk backend.
+struct TopLevel {
+    #[argh(option, long = "block-backend")]
+    /// vhost-user-block backend parameters
+    /// path=<image_path>,socket=<socket_path>,num_queues=<number_of_queues>,queue_size=<size_of_each_queue>,readonly=true|false,direct=true|false,poll_queue=true|false
+    backend_command: String,
+}
+
 fn main() {
     env_logger::init();
 
-    let cmd_arguments = Command::new("vhost-user-blk backend")
-        .version(env!("CARGO_PKG_VERSION"))
-        .author(env!("CARGO_PKG_AUTHORS"))
-        .about("Launch a vhost-user-blk backend.")
-        .arg(
-            Arg::new("block-backend")
-                .long("block-backend")
-                .help(vhost_user_block::SYNTAX)
-                .num_args(1)
-                .required(true),
-        )
-        .get_matches();
+    let toplevel: TopLevel = argh::from_env();
 
-    let backend_command = cmd_arguments.get_one::<String>("block-backend").unwrap();
-    start_block_backend(backend_command);
+    start_block_backend(&toplevel.backend_command);
 }