[RFC PATCH 3/7] Rust: add a slightly more idiomatic wrapper around command handling

[Daniel Axtens]

Add a way to do registering and deregistering of commands that is just
a tiny bit more "Rust-y".

Signed-off-by: Daniel Axtens <dja@axtens.net>
---
 grub-core/Makefile.am                  |  2 +-
 grub-core/lib/rust/grub/src/command.rs | 50 ++++++++++++++++++++++++++
 grub-core/lib/rust/grub/src/lib.rs     |  1 +
 3 files changed, 52 insertions(+), 1 deletion(-)
 create mode 100644 grub-core/lib/rust/grub/src/command.rs

diff --git a/grub-core/Makefile.am b/grub-core/Makefile.am
index 71c1444bcf7d..b565803efb05 100644
--- a/grub-core/Makefile.am
+++ b/grub-core/Makefile.am
@@ -38,7 +38,7 @@ lib/rust/grub/src/bindings.rs: lib/rust/bindings.h
 
 CLEANFILES += lib/rust/grub/src/bindings.rs
 
-COMMON_RUSTSOURCES = lib/rust/grub/src/bindings.rs lib/rust/grub/src/lib.rs
+COMMON_RUSTSOURCES = lib/rust/grub/src/bindings.rs lib/rust/grub/src/lib.rs 
lib/rust/grub/src/command.rs
 else
 COMMON_RUSTSOURCES =
 endif
diff --git a/grub-core/lib/rust/grub/src/command.rs 
b/grub-core/lib/rust/grub/src/command.rs
new file mode 100644
index 000000000000..e96b0ad78608
--- /dev/null
+++ b/grub-core/lib/rust/grub/src/command.rs
@@ -0,0 +1,50 @@
+extern crate alloc;
+use crate::bindings;
+use alloc::string::String;
+use cty;
+
+pub type GrubCommandFunc = unsafe extern "C" fn(
+    cmd: *mut bindings::grub_command,
+    argc: cty::c_int,
+    argv: *mut *mut cty::c_char,
+) -> bindings::grub_err_t;
+
+pub struct GrubCommand {
+    grub_command: bindings::grub_command_t,
+}
+
+impl GrubCommand {
+    pub fn new(
+        name: &'static str,
+        func: GrubCommandFunc,
+        summary: &'static str,
+        description: &'static str,
+    ) -> GrubCommand {
+        let grub_command = register_command_prio(name, func, summary, 
description, 0);
+        GrubCommand { grub_command }
+    }
+}
+
+impl Drop for GrubCommand {
+    fn drop(&mut self) {
+        unsafe { bindings::grub_unregister_command(self.grub_command) };
+    }
+}
+
+fn register_command_prio(
+    name: &'static str,
+    func: GrubCommandFunc,
+    summary: &'static str,
+    description: &'static str,
+    prio: cty::c_int,
+) -> bindings::grub_command_t {
+    unsafe {
+        bindings::grub_register_command_prio(
+            name.as_ptr() as *const _,
+            Some(func),
+            summary.as_ptr() as *const _,
+            description.as_ptr() as *const _,
+            prio,
+        )
+    }
+}
diff --git a/grub-core/lib/rust/grub/src/lib.rs 
b/grub-core/lib/rust/grub/src/lib.rs
index c34f332c88af..02411292ba12 100644
--- a/grub-core/lib/rust/grub/src/lib.rs
+++ b/grub-core/lib/rust/grub/src/lib.rs
@@ -6,6 +6,7 @@
 #![feature(alloc_error_handler)]
 
 pub mod bindings;
+pub mod command;
 use bindings::grub_size_t;
 use core::alloc::GlobalAlloc;
 use core::alloc::Layout;
-- 
2.30.2