RustPython · youknowone · Jan 23, 2026 · Jan 23, 2026 · Jan 23, 2026 · Jan 23, 2026
diff --git a/Cargo.toml b/Cargo.toml
@@ -222,6 +222,7 @@ wasm-bindgen = "0.2.106"
 unsafe_code = "allow"
 unsafe_op_in_unsafe_fn = "deny"
 elided_lifetimes_in_paths = "warn"
+missing_copy_implementations = "warn"
 
 [workspace.lints.clippy]
 # alloc_instead_of_core = "warn"

diff --git a/crates/codegen/src/compile.rs b/crates/codegen/src/compile.rs
@@ -113,13 +113,14 @@ struct Compiler {
     in_annotation: bool,
 }
 
+#[derive(Clone, Copy)]
 enum DoneWithFuture {
     No,
     DoneWithDoc,
     Yes,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Clone, Copy, Debug)]
 pub struct CompileOpts {
     /// How optimized the bytecode output should be; any optimize > 0 does
     /// not emit assert statements

diff --git a/crates/codegen/src/error.rs b/crates/codegen/src/error.rs
@@ -3,7 +3,7 @@ use core::fmt::Display;
 use rustpython_compiler_core::SourceLocation;
 use thiserror::Error;
 
-#[derive(Debug)]
+#[derive(Clone, Copy, Debug)]
 pub enum PatternUnreachableReason {
     NameCapture,
     Wildcard,

diff --git a/crates/codegen/src/ir.rs b/crates/codegen/src/ir.rs
@@ -85,7 +85,7 @@ impl ops::IndexMut<BlockIdx> for Vec<Block> {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Clone, Copy, Debug)]
 pub struct InstructionInfo {
     pub instr: AnyInstruction,
     pub arg: OpArg,
@@ -95,8 +95,8 @@ pub struct InstructionInfo {
     pub except_handler: Option<ExceptHandlerInfo>,
 }
 
-/// Exception handler information for an instruction
-#[derive(Debug, Clone)]
+/// Exception handler information for an instruction.
+#[derive(Clone, Copy, Debug)]
 pub struct ExceptHandlerInfo {
     /// Block to jump to when exception occurs
     pub handler_block: BlockIdx,
@@ -742,13 +742,13 @@ fn generate_exception_table(blocks: &[Block], block_to_index: &[u32]) -> Box<[u8
             // instr_size includes EXTENDED_ARG instructions
             let instr_size = instr.arg.instr_size() as u32;
 
-            match (&current_entry, &instr.except_handler) {
+            match (&current_entry, instr.except_handler) {
                 // No current entry, no handler - nothing to do
                 (None, None) => {}
 
                 // No current entry, handler starts - begin new entry
                 (None, Some(handler)) => {
-                    current_entry = Some((handler.clone(), instr_index));
+                    current_entry = Some((handler, instr_index));
                 }
 
                 // Current entry exists, same handler - continue
@@ -767,7 +767,7 @@ fn generate_exception_table(blocks: &[Block], block_to_index: &[u32]) -> Box<[u8
                         curr_handler.stack_depth as u16,
                         curr_handler.preserve_lasti,
                     ));
-                    current_entry = Some((handler.clone(), instr_index));
+                    current_entry = Some((handler, instr_index));
                 }
 
                 // Current entry exists, no handler - finish current entry

diff --git a/crates/codegen/src/symboltable.rs b/crates/codegen/src/symboltable.rs
@@ -758,7 +758,7 @@ impl SymbolTableAnalyzer {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Clone, Copy, Debug)]
 enum SymbolUsage {
     Global,
     Nonlocal,

diff --git a/crates/common/src/cformat.rs b/crates/common/src/cformat.rs
@@ -14,7 +14,7 @@ use rustpython_literal::{float, format::Case};
 
 use crate::wtf8::{CodePoint, Wtf8, Wtf8Buf};
 
-#[derive(Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum CFormatErrorType {
     UnmatchedKeyParentheses,
     MissingModuloSign,
@@ -27,7 +27,7 @@ pub enum CFormatErrorType {
 // also contains how many chars the parsing function consumed
 pub type ParsingError = (CFormatErrorType, usize);
 
-#[derive(Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub struct CFormatError {
     pub typ: CFormatErrorType, // FIXME
     pub index: usize,

diff --git a/crates/common/src/encodings.rs b/crates/common/src/encodings.rs
@@ -262,6 +262,7 @@ pub mod errors {
     use super::*;
     use core::fmt::Write;
 
+    #[derive(Clone, Copy)]
     pub struct Strict;
 
     impl<Ctx: EncodeContext> EncodeErrorHandler<Ctx> for Strict {
@@ -286,6 +287,7 @@ pub mod errors {
         }
     }
 
+    #[derive(Clone, Copy)]
     pub struct Ignore;
 
     impl<Ctx: EncodeContext> EncodeErrorHandler<Ctx> for Ignore {
@@ -310,6 +312,7 @@ pub mod errors {
         }
     }
 
+    #[derive(Clone, Copy)]
     pub struct Replace;
 
     impl<Ctx: EncodeContext> EncodeErrorHandler<Ctx> for Replace {
@@ -338,6 +341,7 @@ pub mod errors {
         }
     }
 
+    #[derive(Clone, Copy)]
     pub struct XmlCharRefReplace;
 
     impl<Ctx: EncodeContext> EncodeErrorHandler<Ctx> for XmlCharRefReplace {
@@ -358,6 +362,7 @@ pub mod errors {
         }
     }
 
+    #[derive(Clone, Copy)]
     pub struct BackslashReplace;
 
     impl<Ctx: EncodeContext> EncodeErrorHandler<Ctx> for BackslashReplace {
@@ -394,6 +399,7 @@ pub mod errors {
         }
     }
 
+    #[derive(Clone, Copy)]
     pub struct NameReplace;
 
     impl<Ctx: EncodeContext> EncodeErrorHandler<Ctx> for NameReplace {
@@ -422,6 +428,7 @@ pub mod errors {
         }
     }
 
+    #[derive(Clone, Copy)]
     pub struct SurrogateEscape;
 
     impl<Ctx: EncodeContext> EncodeErrorHandler<Ctx> for SurrogateEscape {

diff --git a/crates/common/src/fileutils.rs b/crates/common/src/fileutils.rs
@@ -46,7 +46,7 @@ pub mod windows {
 
     pub const SECS_BETWEEN_EPOCHS: i64 = 11644473600; // Seconds between 1.1.1601 and 1.1.1970
 
-    #[derive(Default)]
+    #[derive(Clone, Copy, Default)]
     pub struct StatStruct {
         pub st_dev: libc::c_ulong,
         pub st_ino: u64,
@@ -256,6 +256,7 @@ pub mod windows {
         m as _
     }
 
+    #[derive(Clone, Copy)]
     #[repr(C)]
     pub struct FILE_STAT_BASIC_INFORMATION {
         pub FileId: i64,
@@ -275,8 +276,9 @@ pub mod windows {
         pub FileId128: [u64; 2],
     }
 
-    #[repr(C)]
     #[allow(dead_code)]
+    #[derive(Clone, Copy)]
+    #[repr(C)]
     pub enum FILE_INFO_BY_NAME_CLASS {
         FileStatByNameInfo,
         FileStatLxByNameInfo,

diff --git a/crates/common/src/format.rs b/crates/common/src/format.rs
@@ -110,7 +110,7 @@ impl FormatParse for FormatSign {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum FormatGrouping {
     Comma,
     Underscore,
@@ -136,7 +136,7 @@ impl From<&FormatGrouping> for char {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum FormatType {
     String,
     Binary,
@@ -199,7 +199,7 @@ impl FormatParse for FormatType {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub struct FormatSpec {
     conversion: Option<FormatConversion>,
     fill: Option<CodePoint>,
@@ -845,7 +845,7 @@ impl Deref for AsciiStr<'_> {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum FormatSpecError {
     DecimalDigitsTooMany,
     PrecisionTooBig,
@@ -862,7 +862,7 @@ pub enum FormatSpecError {
     NotImplemented(char, &'static str),
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum FormatParseError {
     UnmatchedBracket,
     MissingStartBracket,

diff --git a/crates/common/src/hash.rs b/crates/common/src/hash.rs
@@ -25,6 +25,7 @@ pub const SEED_BITS: usize = core::mem::size_of::<u64>() * 2 * 8;
 
 // pub const CUTOFF: usize = 7;
 
+#[derive(Clone, Copy)]
 pub struct HashSecret {
     k0: u64,
     k1: u64,

diff --git a/crates/common/src/int.rs b/crates/common/src/int.rs
@@ -29,7 +29,7 @@ pub fn float_to_ratio(value: f64) -> Option<(BigInt, BigInt)> {
     })
 }
 
-#[derive(Debug, Eq, PartialEq)]
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub enum BytesToIntError {
     InvalidLiteral { base: u32 },
     InvalidBase,

diff --git a/crates/common/src/lock/cell_lock.rs b/crates/common/src/lock/cell_lock.rs
@@ -201,10 +201,14 @@ fn deadlock(lock_kind: &str, ty: &str) -> ! {
     panic!("deadlock: tried to {lock_kind}lock a Cell{ty} twice")
 }
 
+#[derive(Clone, Copy)]
 pub struct SingleThreadId(());
+
 unsafe impl GetThreadId for SingleThreadId {
     const INIT: Self = Self(());
+
     fn nonzero_thread_id(&self) -> NonZero<usize> {
-        NonZero::new(1).unwrap()
+        // Safety: This is constant.
+        unsafe { NonZero::new_unchecked(1) }
     }
 }
diff --git a/crates/common/src/lock/thread_mutex.rs b/crates/common/src/lock/thread_mutex.rs
@@ -121,19 +121,23 @@ impl<R: RawMutex, G: GetThreadId, T: ?Sized> ThreadMutex<R, G, T> {
         }
     }
 }
-// Whether ThreadMutex::try_lock failed because the mutex was already locked on another thread or
-// on the current thread
+
+#[derive(Clone, Copy)]
 pub enum TryLockThreadError {
+    /// Failed to lock because mutex was already locked on another thread.
     Other,
+    /// Failed to lock because mutex was already locked on current thread.
     Current,
 }
 
 struct LockedPlaceholder(&'static str);
+
 impl fmt::Debug for LockedPlaceholder {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.write_str(self.0)
     }
 }
+
 impl<R: RawMutex, G: GetThreadId, T: ?Sized + fmt::Debug> fmt::Debug for ThreadMutex<R, G, T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.try_lock() {

diff --git a/crates/common/src/str.rs b/crates/common/src/str.rs
@@ -449,6 +449,7 @@ pub fn to_ascii(value: &str) -> AsciiString {
     unsafe { AsciiString::from_ascii_unchecked(ascii) }
 }
 
+#[derive(Clone, Copy)]
 pub struct UnicodeEscapeCodepoint(pub CodePoint);
 
 impl fmt::Display for UnicodeEscapeCodepoint {

diff --git a/crates/compiler-core/src/bytecode.rs b/crates/compiler-core/src/bytecode.rs
@@ -32,7 +32,7 @@ mod oparg;
 
 /// Exception table entry for zero-cost exception handling
 /// Format: (start, size, target, depth<<1|lasti)
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub struct ExceptionTableEntry {
     /// Start instruction offset (inclusive)
     pub start: u32,
@@ -47,7 +47,7 @@ pub struct ExceptionTableEntry {
 }
 
 impl ExceptionTableEntry {
-    pub fn new(start: u32, end: u32, target: u32, depth: u16, push_lasti: bool) -> Self {
+    pub const fn new(start: u32, end: u32, target: u32, depth: u16, push_lasti: bool) -> Self {
         Self {
             start,
             end,

diff --git a/crates/compiler-core/src/marshal.rs b/crates/compiler-core/src/marshal.rs
@@ -6,7 +6,7 @@ use rustpython_wtf8::Wtf8;
 
 pub const FORMAT_VERSION: u32 = 5;
 
-#[derive(Debug)]
+#[derive(Clone, Copy, Debug)]
 pub enum MarshalError {
     /// Unexpected End Of File
     Eof,
@@ -42,6 +42,7 @@ impl core::error::Error for MarshalError {}
 
 type Result<T, E = MarshalError> = core::result::Result<T, E>;
 
+#[derive(Clone, Copy)]
 #[repr(u8)]
 enum Type {
     // Null = b'0',

diff --git a/crates/compiler-core/src/mode.rs b/crates/compiler-core/src/mode.rs
@@ -22,7 +22,7 @@ impl core::str::FromStr for Mode {
 }
 
 /// Returned when a given mode is not valid.
-#[derive(Debug)]
+#[derive(Clone, Copy, Debug)]
 pub struct ModeParseError;
 
 impl core::fmt::Display for ModeParseError {

diff --git a/crates/sre_engine/src/constants.rs b/crates/sre_engine/src/constants.rs
@@ -14,9 +14,10 @@
 use bitflags::bitflags;
 
 pub const SRE_MAGIC: usize = 20230612;
-#[derive(num_enum::TryFromPrimitive, Debug, PartialEq, Eq)]
-#[repr(u32)]
+
 #[allow(non_camel_case_types, clippy::upper_case_acronyms)]
+#[derive(num_enum::TryFromPrimitive, Copy, Clone, Debug, PartialEq, Eq)]
+#[repr(u32)]
 pub enum SreOpcode {
     FAILURE = 0,
     SUCCESS = 1,
@@ -63,9 +64,9 @@ pub enum SreOpcode {
     RANGE_UNI_IGNORE = 42,
 }
 
-#[derive(num_enum::TryFromPrimitive, Debug, PartialEq, Eq)]
-#[repr(u32)]
 #[allow(non_camel_case_types, clippy::upper_case_acronyms)]
+#[derive(num_enum::TryFromPrimitive, Clone, Copy, Debug, PartialEq, Eq)]
+#[repr(u32)]
 pub enum SreAtCode {
     BEGINNING = 0,
     BEGINNING_LINE = 1,
@@ -81,9 +82,9 @@ pub enum SreAtCode {
     UNI_NON_BOUNDARY = 11,
 }
 
-#[derive(num_enum::TryFromPrimitive, Debug)]
-#[repr(u32)]
 #[allow(non_camel_case_types, clippy::upper_case_acronyms)]
+#[derive(num_enum::TryFromPrimitive, Clone, Copy, Debug)]
+#[repr(u32)]
 pub enum SreCatCode {
     DIGIT = 0,
     NOT_DIGIT = 1,
@@ -120,6 +121,7 @@ bitflags! {
 }
 
 bitflags! {
+    #[derive(Clone, Copy)]
     pub struct SreInfo: u32 {
         const PREFIX = 1;
         const LITERAL = 2;