style(core/rust): enable clippy lints

[no changelog]

ci/shell.nix

@@ -29,8 +29,8 @@ let
       "thumbv7m-none-eabi"    # T1
     ];
     # we use rustfmt from nixpkgs because it's built with the nighly flag needed for wrap_comments
-    # to use official binary, remove rustfmt from buildInputs below and uncomment next line:
-    # extensions = [ "rustfmt" ];
+    # to use official binary, remove rustfmt from buildInputs and add it to extensions:
+    extensions = [ "clippy" ];
   };
 in
 with nixpkgs;

ci/test.yml

@@ -9,6 +9,7 @@ core unit test:
   script:
     - nix-shell --run "poetry run make -C core test | ts -s"
     - nix-shell --run "poetry run make -C core test_rust | ts -s"
+    - nix-shell --run "poetry run make -C core clippy | ts -s"
 
 core device ui test:
   stage: test

core/Makefile

@@ -118,6 +118,9 @@ mypy:
 		src/apps/webauthn \
 		src/trezor/ui
 
+clippy:
+	cd embed/rust ; cargo clippy
+
 ## code generation:
 
 templates: ## render Mako templates (for lists of coins, tokens, etc.)

core/embed/rust/build.rs

@@ -150,7 +150,7 @@ fn generate_micropython_bindings() {
             .lines()
             .skip_while(|s| !s.contains("search starts here:"))
             .take_while(|s| !s.contains("End of search list."))
-            .filter(|s| s.starts_with(" "))
+            .filter(|s| s.starts_with(' '))
             .map(|s| format!("-I{}", s.trim()));
 
         bindings = bindings.clang_args(include_args);

core/embed/rust/src/error.rs

@@ -4,6 +4,7 @@ use cstr_core::CStr;
 use crate::micropython::{ffi, obj::Obj, qstr::Qstr};
 
 #[derive(Debug)]
+#[allow(clippy::enum_variant_names)]
 pub enum Error {
     TypeError,
     OutOfRange,
@@ -22,7 +23,7 @@ impl Error {
     /// exception, because the object is not guaranteed to remain intact.
     /// Micropython might reuse the same space for creating a different
     /// exception.
-    pub unsafe fn to_obj(self) -> Obj {
+    pub unsafe fn into_obj(self) -> Obj {
         unsafe {
             // SAFETY:
             // - first argument is a reference to a valid exception type
@@ -34,7 +35,7 @@ impl Error {
                 Error::AllocationFailed => ffi::mp_obj_new_exception(&ffi::mp_type_MemoryError),
                 Error::CaughtException(obj) => obj,
                 Error::KeyError(key) => {
-                    ffi::mp_obj_new_exception_args(&ffi::mp_type_KeyError, 1, &key.into())
+                    ffi::mp_obj_new_exception_args(&ffi::mp_type_KeyError, 1, &key)
                 }
                 Error::ValueError(msg) => {
                     if let Ok(msg) = msg.try_into() {
@@ -45,7 +46,7 @@ impl Error {
                 }
                 Error::ValueErrorParam(msg, param) => {
                     if let Ok(msg) = msg.try_into() {
-                        let args: [Obj; 2] = [msg, param.into()];
+                        let args: [Obj; 2] = [msg, param];
                         ffi::mp_obj_new_exception_args(&ffi::mp_type_ValueError, 2, args.as_ptr())
                     } else {
                         ffi::mp_obj_new_exception(&ffi::mp_type_ValueError)

core/embed/rust/src/lib.rs

@@ -30,5 +30,5 @@ fn panic(_info: &PanicInfo) -> ! {
 
     // TODO: Ideally we would take the file and line info out of
     // `PanicInfo::location()`.
-    trezorhal::common::fatal_error(&empty, &msg, &empty, 0, &empty);
+    trezorhal::common::fatal_error(empty, msg, empty, 0, empty);
 }

core/embed/rust/src/micropython/func.rs

@@ -4,7 +4,7 @@ pub type Func = ffi::mp_obj_fun_builtin_fixed_t;
 
 impl Func {
     /// Convert a "static const" function to a MicroPython object.
-    pub const fn to_obj(&'static self) -> Obj {
+    pub const fn as_obj(&'static self) -> Obj {
         // SAFETY:
         //  - We are an object struct with a base and a type.
         //  - 'static lifetime holds us in place.

core/embed/rust/src/micropython/map.rs

@@ -40,7 +40,7 @@ impl Map {
 }
 
 impl Map {
-    pub fn from_fixed<'a>(table: &'a [MapElem]) -> MapRef<'a> {
+    pub fn from_fixed(table: &[MapElem]) -> MapRef {
         let mut map = MaybeUninit::uninit();
         // SAFETY: `mp_map_init_fixed_table` completely initializes all fields of `map`.
         unsafe {

core/embed/rust/src/micropython/obj.rs

@@ -129,7 +129,8 @@ impl TryFrom<Obj> for bool {
         // SAFETY:
         //  - `obj` can be anything uPy understands.
         // EXCEPTION: Can call Python code (on custom instances) and therefore raise.
-        if catch_exception(|| unsafe { ffi::mp_obj_is_true(obj) })? {
+        let result = catch_exception(|| unsafe { ffi::mp_obj_is_true(obj) })?;
+        if result {
             Ok(true)
         } else {
             Ok(false)

core/embed/rust/src/micropython/runtime.rs

@@ -14,8 +14,8 @@ pub unsafe fn raise_exception(err: Error) -> ! {
     unsafe {
         // SAFETY:
         // - argument must be an exception instance
-        // (err.to_obj() should return the right thing)
-        ffi::nlr_jump(err.to_obj().as_ptr());
+        // (err.into_obj() should return the right thing)
+        ffi::nlr_jump(err.into_obj().as_ptr());
     }
     panic!();
 }

core/embed/rust/src/micropython/typ.rs

@@ -19,7 +19,7 @@ impl Type {
         }
     }
 
-    pub fn to_base(&'static self) -> ObjBase {
+    pub fn as_base(&'static self) -> ObjBase {
         ObjBase { type_: self }
     }
 }

core/embed/rust/src/protobuf/defs.rs

@@ -126,8 +126,7 @@ pub fn find_name_by_msg_offset(msg_offset: u16) -> Result<u16, Error> {
 
     name_defs
         .iter()
-        .filter(|def| def.msg_offset == msg_offset)
-        .next()
+        .find(|def| def.msg_offset == msg_offset)
         .map(|def| def.msg_name)
         .ok_or_else(|| Error::KeyError(msg_offset.into()))
 }

core/embed/rust/src/protobuf/encode.rs

@@ -29,7 +29,7 @@ pub extern "C" fn protobuf_len(obj: Obj) -> Obj {
 
         Encoder.encode_message(stream, &obj.def(), &obj)?;
 
-        Ok(stream.len.try_into()?)
+        stream.len.try_into()
     };
     unsafe { util::try_or_raise(block) }
 }
@@ -46,7 +46,7 @@ pub extern "C" fn protobuf_encode(buf: Obj, obj: Obj) -> Obj {
 
         Encoder.encode_message(stream, &obj.def(), &obj)?;
 
-        Ok(stream.len().try_into()?)
+        stream.len().try_into()
     };
     unsafe { util::try_or_raise(block) }
 }

core/embed/rust/src/protobuf/obj.rs

@@ -28,7 +28,7 @@ pub struct MsgObj {
 impl MsgObj {
     pub fn alloc_with_capacity(capacity: usize, msg: &MsgDef) -> Result<Gc<Self>, Error> {
         Gc::new(Self {
-            base: Self::obj_type().to_base(),
+            base: Self::obj_type().as_base(),
             map: Map::with_capacity(capacity)?,
             msg_wire_id: msg.wire_id,
             msg_offset: msg.offset,
@@ -100,13 +100,13 @@ impl MsgObj {
     }
 }
 
-impl Into<Obj> for Gc<MsgObj> {
-    fn into(self) -> Obj {
+impl From<Gc<MsgObj>> for Obj {
+    fn from(value: Gc<MsgObj>) -> Self {
         // SAFETY:
-        //  - We are GC-allocated.
-        //  - We are `repr(C)`.
-        //  - We have a `base` as the first field with the correct type.
-        unsafe { Obj::from_ptr(Self::into_raw(self).cast()) }
+        //  - `value` is GC-allocated.
+        //  - `value` is `repr(C)`.
+        //  - `value` has a `base` as the first field with the correct type.
+        unsafe { Self::from_ptr(Gc::into_raw(value).cast()) }
     }
 }
 
@@ -155,7 +155,7 @@ pub struct MsgDefObj {
 impl MsgDefObj {
     pub fn alloc(def: MsgDef) -> Result<Gc<Self>, Error> {
         let this = Gc::new(Self {
-            base: Self::obj_type().to_base(),
+            base: Self::obj_type().as_base(),
             def,
         })?;
         Ok(this)
@@ -175,13 +175,13 @@ impl MsgDefObj {
     }
 }
 
-impl Into<Obj> for Gc<MsgDefObj> {
-    fn into(self) -> Obj {
+impl From<Gc<MsgDefObj>> for Obj {
+    fn from(value: Gc<MsgDefObj>) -> Self {
         // SAFETY:
-        //  - We are GC-allocated.
-        //  - We are `repr(C)`.
-        //  - We have a `base` as the first field with the correct type.
-        unsafe { Obj::from_ptr(Self::into_raw(self).cast()) }
+        //  - `value` is GC-allocated.
+        //  - `value` is `repr(C)`.
+        //  - `value` has a `base` as the first field with the correct type.
+        unsafe { Self::from_ptr(Gc::into_raw(value).cast()) }
     }
 }
 
@@ -234,7 +234,7 @@ unsafe extern "C" fn msg_def_obj_attr(self_in: Obj, attr: ffi::qstr, dest: *mut
                 // dest[0] = function_obj
                 // dest[1] = self
                 unsafe {
-                    dest.write(MSG_DEF_OBJ_IS_TYPE_OF_OBJ.to_obj());
+                    dest.write(MSG_DEF_OBJ_IS_TYPE_OF_OBJ.as_obj());
                     dest.offset(1).write(self_in);
                 }
             }