fixes more clippy warnings (#6543)

* fixes more clippy warnings

* Fix x86 c_callable to have doc_strings

9 files changed, 52 insertions, 87 deletions

diff --git a/yjit/src/asm/mod.rs b/yjit/src/asm/mod.rs
index 2bc83ec059..8356201ba6 100644
--- a/yjit/src/asm/mod.rs
+++ b/yjit/src/asm/mod.rs
@@ -300,7 +300,7 @@ impl CodeBlock {
 }
 
 /// Produce hex string output from the bytes in a code block
-impl<'a> fmt::LowerHex for CodeBlock {
+impl fmt::LowerHex for CodeBlock {
     fn fmt(&self, fmtr: &mut fmt::Formatter) -> fmt::Result {
         for pos in 0..self.write_pos {
             let byte = unsafe { self.mem_block.start_ptr().raw_ptr().add(pos).read() };
@@ -393,7 +393,7 @@ mod tests
         assert_eq!(uimm_num_bits(((u16::MAX as u32) + 1).into()), 32);
         assert_eq!(uimm_num_bits(u32::MAX.into()), 32);
 
-        assert_eq!(uimm_num_bits(((u32::MAX as u64) + 1)), 64);
+        assert_eq!(uimm_num_bits((u32::MAX as u64) + 1), 64);
         assert_eq!(uimm_num_bits(u64::MAX), 64);
     }
 }
diff --git a/yjit/src/backend/arm64/mod.rs b/yjit/src/backend/arm64/mod.rs
index ee4f96c0d8..0180737d4d 100644
--- a/yjit/src/backend/arm64/mod.rs
+++ b/yjit/src/backend/arm64/mod.rs
@@ -71,7 +71,7 @@ impl Assembler
     // A special scratch register for intermediate processing.
     // This register is caller-saved (so we don't have to save it before using it)
     const SCRATCH0: A64Opnd = A64Opnd::Reg(X16_REG);
-    const SCRATCH1: A64Opnd = A64Opnd::Reg(X17_REG);    
+    const SCRATCH1: A64Opnd = A64Opnd::Reg(X17_REG);
 
     /// Get the list of registers from which we will allocate on this platform
     /// These are caller-saved registers
@@ -281,6 +281,9 @@ impl Assembler
                 };
             }
 
+            // We are replacing instructions here so we know they are already
+            // being used. It is okay not to use their output here.
+            #[allow(unused_must_use)]
             match insn {
                 Insn::Add { left, right, .. } => {
                     match (left, right) {
diff --git a/yjit/src/backend/ir.rs b/yjit/src/backend/ir.rs
index dfdc1deb0d..ba7e372188 100644
--- a/yjit/src/backend/ir.rs
+++ b/yjit/src/backend/ir.rs
@@ -220,7 +220,7 @@ impl From<usize> for Opnd {
 
 impl From<u64> for Opnd {
     fn from(value: u64) -> Self {
-        Opnd::UImm(value.try_into().unwrap())
+        Opnd::UImm(value)
     }
 }
 
diff --git a/yjit/src/backend/tests.rs b/yjit/src/backend/tests.rs
index 440b66d69a..1df726c468 100644
--- a/yjit/src/backend/tests.rs
+++ b/yjit/src/backend/tests.rs
@@ -1,47 +1,14 @@
 #![cfg(test)]
-
 use crate::asm::{CodeBlock};
-use crate::virtualmem::{CodePtr};
 use crate::backend::ir::*;
 use crate::cruby::*;
-use crate::core::*;
 use crate::utils::c_callable;
-use InsnOpnd::*;
-
-// Test that this function type checks
-fn gen_dup(
-    ctx: &mut Context,
-    asm: &mut Assembler,
-) {
-    let dup_val = ctx.stack_pop(0);
-    let (mapping, tmp_type) = ctx.get_opnd_mapping(StackOpnd(0));
-
-    let loc0 = ctx.stack_push_mapping((mapping, tmp_type));
-    asm.mov(loc0, dup_val);
-}
-
-fn guard_object_is_heap(
-    asm: &mut Assembler,
-    object_opnd: Opnd,
-    ctx: &mut Context,
-    side_exit: CodePtr,
-) {
-    asm.comment("guard object is heap");
-
-    // Test that the object is not an immediate
-    asm.test(object_opnd, Opnd::UImm(RUBY_IMMEDIATE_MASK as u64));
-    asm.jnz(Target::CodePtr(side_exit));
-
-    // Test that the object is not false or nil
-    asm.cmp(object_opnd, Opnd::UImm(Qnil.into()));
-    asm.jbe(Target::CodePtr(side_exit));
-}
 
 #[test]
 fn test_add() {
     let mut asm = Assembler::new();
     let out = asm.add(SP, Opnd::UImm(1));
-    asm.add(out, Opnd::UImm(2));
+    let _ = asm.add(out, Opnd::UImm(2));
 }
 
 #[test]
@@ -52,21 +19,21 @@ fn test_alloc_regs() {
     let out1 = asm.add(EC, Opnd::UImm(1));
 
     // Pad some instructions in to make sure it can handle that.
-    asm.add(EC, Opnd::UImm(2));
+    let _ = asm.add(EC, Opnd::UImm(2));
 
     // Get the second output we're going to reuse.
     let out2 = asm.add(EC, Opnd::UImm(3));
 
     // Pad another instruction.
-    asm.add(EC, Opnd::UImm(4));
+    let _ =  asm.add(EC, Opnd::UImm(4));
 
     // Reuse both the previously captured outputs.
-    asm.add(out1, out2);
+    let _ = asm.add(out1, out2);
 
     // Now get a third output to make sure that the pool has registers to
     // allocate now that the previous ones have been returned.
     let out3 = asm.add(EC, Opnd::UImm(5));
-    asm.add(out3, Opnd::UImm(6));
+    let _ = asm.add(out3, Opnd::UImm(6));
 
     // Here we're going to allocate the registers.
     let result = asm.alloc_regs(Assembler::get_alloc_regs());
@@ -198,7 +165,7 @@ fn test_base_insn_out()
 fn test_c_call()
 {
     c_callable! {
-        fn dummy_c_fun(v0: usize, v1: usize) {}
+        fn dummy_c_fun(_v0: usize, _v1: usize) {}
     }
 
     let (mut asm, mut cb) = setup_asm();
@@ -305,11 +272,12 @@ fn test_bake_string() {
 
 #[test]
 fn test_draining_iterator() {
+
     let mut asm = Assembler::new();
 
-    asm.load(Opnd::None);
+    let _ = asm.load(Opnd::None);
     asm.store(Opnd::None, Opnd::None);
-    asm.add(Opnd::None, Opnd::None);
+    let _ = asm.add(Opnd::None, Opnd::None);
 
     let mut iter = asm.into_draining_iter();
 
@@ -327,11 +295,11 @@ fn test_draining_iterator() {
 fn test_lookback_iterator() {
     let mut asm = Assembler::new();
 
-    asm.load(Opnd::None);
+    let _ = asm.load(Opnd::None);
     asm.store(Opnd::None, Opnd::None);
     asm.store(Opnd::None, Opnd::None);
 
-    let mut iter = asm.into_lookback_iter();
+    let iter = asm.into_lookback_iter();
 
     while let Some((index, insn)) = iter.next_unmapped() {
         if index > 0 {
diff --git a/yjit/src/codegen.rs b/yjit/src/codegen.rs
index 8b0409649f..f8379a7159 100644
--- a/yjit/src/codegen.rs
+++ b/yjit/src/codegen.rs
@@ -189,13 +189,6 @@ fn jit_peek_at_block_handler(jit: &JITState, level: u32) -> VALUE {
     }
 }
 
-// Add a comment at the current position in the code block
-fn add_comment(cb: &mut CodeBlock, comment_str: &str) {
-    if cfg!(feature = "asm_comments") {
-        cb.add_comment(comment_str);
-    }
-}
-
 /// Increment a profiling counter with counter_name
 #[cfg(not(feature = "stats"))]
 macro_rules! gen_counter_incr {
@@ -6804,7 +6797,7 @@ mod tests {
 
     #[test]
     fn test_gen_check_ints() {
-        let (_, _ctx, mut asm, mut cb, mut ocb) = setup_codegen();
+        let (_, _ctx, mut asm, _cb, mut ocb) = setup_codegen();
         let side_exit = ocb.unwrap().get_write_ptr();
         gen_check_ints(&mut asm, side_exit);
     }
@@ -6822,7 +6815,7 @@ mod tests {
 
     #[test]
     fn test_gen_pop() {
-        let (mut jit, _, mut asm, mut cb, mut ocb) = setup_codegen();
+        let (mut jit, _, mut asm, _cb, mut ocb) = setup_codegen();
         let mut context = Context::new_with_stack_size(1);
         let status = gen_pop(&mut jit, &mut context, &mut asm, &mut ocb);
 
@@ -6872,7 +6865,7 @@ mod tests {
 
     #[test]
     fn test_gen_swap() {
-        let (mut jit, mut context, mut asm, mut cb, mut ocb) = setup_codegen();
+        let (mut jit, mut context, mut asm, _cb, mut ocb) = setup_codegen();
         context.stack_push(Type::Fixnum);
         context.stack_push(Type::Flonum);
 
@@ -6940,7 +6933,7 @@ mod tests {
 
     #[test]
     fn test_int2fix() {
-        let (mut jit, mut context, mut asm, mut cb, mut ocb) = setup_codegen();
+        let (mut jit, mut context, mut asm, _cb, mut ocb) = setup_codegen();
         jit.opcode = YARVINSN_putobject_INT2FIX_0_.as_usize();
         let status = gen_putobject_int2fix(&mut jit, &mut context, &mut asm, &mut ocb);
 
@@ -7029,7 +7022,7 @@ mod tests {
 
     #[test]
     fn test_gen_leave() {
-        let (mut jit, mut context, mut asm, mut cb, mut ocb) = setup_codegen();
+        let (mut jit, mut context, mut asm, _cb, mut ocb) = setup_codegen();
         // Push return value
         context.stack_push(Type::Fixnum);
         gen_leave(&mut jit, &mut context, &mut asm, &mut ocb);
diff --git a/yjit/src/core.rs b/yjit/src/core.rs
index ec9384c403..c8078bb6e3 100644
--- a/yjit/src/core.rs
+++ b/yjit/src/core.rs
@@ -585,10 +585,8 @@ pub extern "C" fn rb_yjit_iseq_mark(payload: *mut c_void) {
             // Mark outgoing branch entries
             for branch in &block.outgoing {
                 let branch = branch.borrow();
-                for target in &branch.targets {
-                    if let Some(target) = target {
-                        unsafe { rb_gc_mark_movable(target.iseq.into()) };
-                    }
+                for target in branch.targets.iter().flatten() {
+                    unsafe { rb_gc_mark_movable(target.iseq.into()) };
                 }
             }
 
@@ -643,10 +641,8 @@ pub extern "C" fn rb_yjit_iseq_update_references(payload: *mut c_void) {
             // Update outgoing branch entries
             for branch in &block.outgoing {
                 let mut branch = branch.borrow_mut();
-                for target in &mut branch.targets {
-                    if let Some(target) = target {
-                        target.iseq = unsafe { rb_gc_location(target.iseq.into()) }.as_iseq();
-                    }
+                for target in branch.targets.iter_mut().flatten() {
+                    target.iseq = unsafe { rb_gc_location(target.iseq.into()) }.as_iseq();
                 }
             }
 
@@ -1605,9 +1601,10 @@ fn make_branch_entry(block: &BlockRef, src_ctx: &Context, gen_fn: BranchGenFn) -
     return branchref;
 }
 
-/// Generated code calls this function with the SysV calling convention.
-/// See [get_branch_target].
+
 c_callable! {
+    /// Generated code calls this function with the SysV calling convention.
+    /// See [get_branch_target].
     fn branch_stub_hit(
         branch_ptr: *const c_void,
         target_idx: u32,
@@ -2018,14 +2015,12 @@ fn free_block(blockref: &BlockRef) {
         let out_branch = out_branchref.borrow();
 
         // For each successor block
-        for succ in &out_branch.blocks {
-            if let Some(succ) = succ {
-                // Remove outgoing branch from the successor's incoming list
-                let mut succ_block = succ.borrow_mut();
-                succ_block
-                    .incoming
-                    .retain(|succ_incoming| !Rc::ptr_eq(succ_incoming, out_branchref));
-            }
+        for succ in out_branch.blocks.iter().flatten() {
+            // Remove outgoing branch from the successor's incoming list
+            let mut succ_block = succ.borrow_mut();
+            succ_block
+                .incoming
+                .retain(|succ_incoming| !Rc::ptr_eq(succ_incoming, out_branchref));
         }
     }
 
diff --git a/yjit/src/cruby.rs b/yjit/src/cruby.rs
index 5ddc31a06d..f31390fc57 100644
--- a/yjit/src/cruby.rs
+++ b/yjit/src/cruby.rs
@@ -96,6 +96,7 @@ pub type size_t = u64;
 pub type RedefinitionFlag = u32;
 
 #[allow(dead_code)]
+#[allow(clippy::useless_transmute)]
 mod autogened {
     use super::*;
     // Textually include output from rust-bindgen as suggested by its user guide.
diff --git a/yjit/src/disasm.rs b/yjit/src/disasm.rs
index c236d9055d..10a89bafd0 100644
--- a/yjit/src/disasm.rs
+++ b/yjit/src/disasm.rs
@@ -70,11 +70,8 @@ pub fn disasm_iseq_insn_range(iseq: IseqPtr, start_idx: u32, end_idx: u32) -> St
         total_code_size += blockref.borrow().code_size();
     }
 
-    out.push_str(&format!("NUM BLOCK VERSIONS: {}\n", block_list.len()));
-    out.push_str(&format!(
-        "TOTAL INLINE CODE SIZE: {} bytes\n",
-        total_code_size
-    ));
+    writeln!(out, "NUM BLOCK VERSIONS: {}", block_list.len()).unwrap();
+    writeln!(out,  "TOTAL INLINE CODE SIZE: {} bytes", total_code_size).unwrap();
 
     // For each block, sorted by increasing start address
     for block_idx in 0..block_list.len() {
@@ -95,7 +92,7 @@ pub fn disasm_iseq_insn_range(iseq: IseqPtr, start_idx: u32, end_idx: u32) -> St
                 end_idx,
                 code_size
             );
-            out.push_str(&format!("== {:=<60}\n", block_ident));
+            writeln!(out, "== {:=<60}", block_ident).unwrap();
 
             // Disassemble the instructions
             out.push_str(&disasm_addr_range(global_cb, start_addr, code_size));
@@ -109,7 +106,7 @@ pub fn disasm_iseq_insn_range(iseq: IseqPtr, start_idx: u32, end_idx: u32) -> St
 
                 // Log the size of the gap between the blocks if nonzero
                 if gap_size > 0 {
-                    out.push_str(&format!("... {} byte gap ...\n", gap_size));
+                    writeln!(out, "... {} byte gap ...", gap_size).unwrap();
                 }
             }
         }
@@ -141,7 +138,7 @@ pub fn disasm_addr_range(cb: &CodeBlock, start_addr: *const u8, code_size: usize
         .detail(true)
         .build()
         .unwrap();
-    cs.set_skipdata(true);
+    cs.set_skipdata(true).unwrap();
 
     // Disassemble the instructions
     let code_slice = unsafe { std::slice::from_raw_parts(start_addr, code_size) };
diff --git a/yjit/src/utils.rs b/yjit/src/utils.rs
index bea57e4fc2..cabebb7dcc 100644
--- a/yjit/src/utils.rs
+++ b/yjit/src/utils.rs
@@ -122,12 +122,20 @@ yjit_print_iseq(const rb_iseq_t *iseq)
 
 #[cfg(target_arch = "aarch64")]
 macro_rules! c_callable {
-    (fn $f:ident $args:tt $(-> $ret:ty)? $body:block) => { extern "C" fn $f $args $(-> $ret)? $body };
+    ($(#[$outer:meta])*
+    fn $f:ident $args:tt $(-> $ret:ty)? $body:block) => {
+        $(#[$outer])*
+        extern "C" fn $f $args $(-> $ret)? $body
+    };
 }
 
 #[cfg(target_arch = "x86_64")]
 macro_rules! c_callable {
-    (fn $f:ident $args:tt $(-> $ret:ty)? $body:block) => { extern "sysv64" fn $f $args $(-> $ret)? $body };
+    ($(#[$outer:meta])*
+    fn $f:ident $args:tt $(-> $ret:ty)? $body:block) => {
+        $(#[$outer])*
+        extern "sysv64" fn $f $args $(-> $ret)? $body
+    };
 }
 pub(crate) use c_callable;