rust: Generate shell (e.g. bash) completion scripts via build.rs for all tools

It might be handy to have shell completion support for the Rust PV
tools.

Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>

rust/pvapconfig/Cargo.toml

@@ -16,3 +16,8 @@ regex = "1.7"
 serde = { version = "1.0.139", features = ["derive"] }
 serde_yaml = "0.9"
 utils = { path = "../utils" }
+
+[build-dependencies]
+clap = { version ="4.1", features = ["derive", "wrap_help"]}
+clap_complete = "4.1"
+lazy_static = "1.1"

rust/pvapconfig/build.rs

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: MIT
+//
+// Copyright IBM Corp. 2024
+// it under the terms of the MIT license. See LICENSE for details.
+
+use clap::{CommandFactory, ValueEnum};
+use clap_complete::{generate_to, Shell};
+use std::env;
+use std::io::Error;
+
+include!("src/cli.rs");
+
+fn main() -> Result<(), Error> {
+    let outdir = env::var_os("OUT_DIR").unwrap();
+    let crate_name = env!("CARGO_PKG_NAME");
+    let mut cmd = Cli::command();
+    for &shell in Shell::value_variants() {
+        generate_to(shell, &mut cmd, crate_name, &outdir)?;
+    }
+
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed=src/cli.rs");
+    Ok(())
+}