Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@crates/codegen/src/compile.rs`:
- Around line 8737-8740: The flag do_not_emit_bytecode only prevents emitting
instructions in _emit(), but helpers like emit_load_const call arg_constant()
(which interns constants) before _emit(), leaking metadata; modify emit helpers
(e.g., emit_load_const) and/or arg_constant() to check do_not_emit_bytecode and
skip interning when do_not_emit_bytecode > 0 so no constants/names are added
while bytecode emission is disabled, ensuring _emit, emit_load_const,
arg_constant (and any other helpers that mutate constant/name tables) return
early or no-op metadata mutations when the flag is set.
- Around line 3871-3885: The PEP 479 StopIteration wrapper currently wraps only
compile_function_body() and omits generator/coroutine code objects created in
compile_comprehension(), causing StopIteration to escape; modify
compile_comprehension() to mirror the same logic used where is_gen is computed
(create handler_block via new_block(), emit PseudoInstruction::SetupCleanup {
delta: handler_block }, and call push_fblock(FBlockType::StopIteration,
handler_block, handler_block) when the comprehension builds a
generator/coroutine) or refactor the wrapper into a small helper used by both
compile_function_body() and compile_comprehension(); also apply the same fix to
the duplicate site referenced around the other block (the section analogous to
3917-3929).
- Around line 8943-8963: The current expr_constant implementation incorrectly
returns Some(!elts.is_empty()) for ast::Expr::Tuple, which folds away element
evaluation (and side effects) for non-empty tuples; change this to only return
Some(false) for an empty tuple and for non-empty tuples return Some(true) only
if every element is a compile-time constant (call expr_constant recursively on
each element and if any returns None, return None), otherwise return None so
elements with possible side effects are preserved; update the ast::Expr::Tuple
branch in expr_constant accordingly (check elts, recurse into each elt, and only
yield Some(true) when all elts are constant).
- Around line 5217-5224: The current early-return for constant == Some(true)
skips compiling the elif/else tests, which bypasses async-await validation and
leaves nested scope sub_tables unconsumed; instead, keep the no-emission mode
but still compile each clause's test expressions (and any nested
lambdas/comprehensions) so errors and scope consumption occur. Concretely,
inside the constant == Some(true) branch where you call self.emit_nop() and
self.compile_statements(body) and adjust self.do_not_emit_bytecode, also iterate
over elif_else_clauses and call the same compiler path that validates/compiles
their test expressions (e.g. use the existing expression-compile routine used
for condition checks) with do_not_emit_bytecode incremented so no bytecode is
emitted but await-checks and sub_table consumption run; do not compile clause
bodies, only their tests/scopes. Ensure you reference self.compile_statements,
elif_else_clauses, and self.do_not_emit_bytecode when making the change.
- Around line 8992-8994: The early return when self.do_not_emit_bytecode > 0
skips loop/except* validation and lets dead branches (e.g., `if False: break`)
pass; instead, preserve the validation logic and only skip emission. Change the
code around the `if self.do_not_emit_bytecode > 0 { return Ok(()); }` guard so
that you still execute the loop/except* checks that follow (the
dead-branch/`break`/`continue` and `except*` validation code) but bypass only
the bytecode emission paths—e.g., wrap emission-specific calls with a check `if
self.do_not_emit_bytecode == 0 { ... }` or move the `return` to after the
validation block; keep references to `self.do_not_emit_bytecode`, the
loop/except* validation code paths, and emission sites to locate and update the
necessary conditionals.

In `@crates/codegen/src/ir.rs`:
- Around line 193-196: The binop-constant folding pass should run again after
UNARY_NEGATIVE has been folded into LOAD_CONST so expressions like `-1 + 2` and
`2 * -3` are caught; update the sequence around fold_binop_constants(),
fold_unary_negative(), and remove_nops() to call fold_binop_constants() once
more immediately after fold_unary_negative() (keeping the surrounding
remove_nops() calls as needed) so binary constant folding re-runs on the newly
produced constants.
- Around line 787-798: The BinOp::FloorDivide and BinOp::Remainder folding
currently uses Rust’s / and % which produce non-Python semantics for BigInt and
floats; change the BigInt cases to call malachite_bigint::BigInt methods
.div_floor() and .mod_floor() (used by the runtime) instead of l / r and l % r,
and for the float remainder branch replicate the Python floor-mod behavior by
applying the sign-correction logic from float_ops::mod_() (or the divmod helper)
so result sign follows the divisor (i.e., matches Python’s // and % semantics
for negative values).

Verify each finding against the current code and only fix it if needed.

Duplicate comments:
In `@crates/codegen/src/compile.rs`:
- Around line 8745-8748: The do_not_emit_bytecode flag currently only prevents
bytecode writes in _emit(), but other helpers (emit_resume_for_scope,
arg_constant, _name_inner, etc.) still mutate constants/names/metadata and
directly write Resume, which leaves partially-formed nested code objects; update
those helpers to consult the same do_not_emit_bytecode guard (or route all
emission through _emit) so that emit_resume_for_scope uses _emit or checks
do_not_emit_bytecode before writing Resume, and modify arg_constant() and
_name_inner() to avoid mutating const/name tables when do_not_emit_bytecode > 0
(or defer metadata mutation until after the guard clears), ensuring no metadata
changes occur unless _emit actually runs.
- Around line 3871-3886: The PEP 479 wrapper is only being applied around
compile_function_body() so non-inlined comprehension code objects built in
compile_comprehension() can still let StopIteration escape; update
compile_comprehension() (and the same pattern around the other location noted)
to create the same stop_iteration_block logic used above: detect is_gen
(is_async || current_symbol_table().is_generator), emit a
PseudoInstruction::SetupCleanup with the new handler_block, call
set_no_location(), push_fblock(FBlockType::StopIteration, handler_block,
handler_block) before compiling the comprehension body, and ensure you
emit/clear the handler_block (stop_iteration_block) exactly like the
compile_function_body() path so comprehensions get the same StopIteration
handler.
- Around line 5219-5228: The current branch that handles constant true tests
skips compiling the tests of dead elif/else clauses, which bypasses validation
and can mis-order sub_tables; in the block where constant == Some(true)
(referencing elif_else_clauses, do_not_emit_bytecode, and compile_statements),
keep do_not_emit_bytecode incremented but invoke the compiler on each dead
clause's test before compiling its body (e.g., call the method that compiles
expressions/tests for each clause — the same routine used for live tests — while
do_not_emit_bytecode is set), then compile_statements(&clause.body) as before so
validation and sub_table consumption occur in the correct order.
- Around line 8959-8979: The current expr_constant implementation treats any
non-empty tuple as a compile-time true (Some(!elts.is_empty())), which can drop
element evaluation and side effects; update the ast::Expr::Tuple arm in
expr_constant so that: if elts.is_empty() return Some(false); otherwise iterate
each element in elts and call expr_constant on it — if any element returns None
then return None (preserve side effects), but if every element returns Some(_)
then return Some(true). Reference: function expr_constant, match arm
ast::Expr::Tuple and the elts iterator.

---

Nitpick comments:
In `@crates/codegen/src/ir.rs`:
- Around line 881-892: In the ConstantData multiplication arm (matching
ConstantData::Str { value: s } and ConstantData::Integer { value: n } when
BinOp::Multiply), pre-check the resulting byte/char size before allocating:
convert n safely (as currently done), compute s.len() and check
s.len().checked_mul(n).filter(|&len| len <= MAX_ALLOWED_BYTES).ok_or_none()? (or
return None) to avoid large allocations, then call repeat(n) only if the product
is within the limit (replace the current n > 4096 guard with this product-based
check); reference symbols: ConstantData::Str, ConstantData::Integer,
BinOp::Multiply, and the local variable s and n.

In `@crates/compiler-core/src/bytecode.rs`:
- Around line 140-142: The function build_no_location_mask currently creates an
empty Vec and then resizes it; replace that pattern by initializing the boolean
vector idiomatically with vec![false; num_units]. Locate
build_no_location_mask(linetable: &[u8], num_units: usize) and change the mask
construction to use the vec![false; num_units] form so the vector is allocated
and filled in one expression.

In `@crates/vm/src/frame.rs`:
- Around line 1793-1795: Extract the repeated restart logic used in the Ok(None)
branches into a small helper (e.g., restart_after_throw or handle_throw_restart)
that sets *self.prev_line = 0 and calls self.run(vm), then replace each Ok(None)
branch (the ones calling *self.prev_line = 0; self.run(vm)) with a single call
to that helper; update any throw/unwind paths that currently duplicate this
pattern (including occurrences around the Ok(None) branches at the shown
locations) so the differing value (the branch-specific context) is computed
first and the common restart helper is invoked once.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@crates/codegen/src/compile.rs`:
- Around line 2110-2122: The NAME→FAST rewrite must be limited to when we are
compiling the inlined comprehension body; update the conditional that sets
op_type (the matches!(op_type, NameOp::Name) &&
self.current_code_info().metadata.fast_hidden.get(name.as_ref()).is_some_and(|&v|
v) branch) to also require a guard that we are currently inside the active
inlined comprehension (for example check an existing flag or counter like
self.inlining_comprehension/ self.inlined_comprehension_depth or a metadata
marker on current_code_info() such as
current_code_info().metadata.is_inlined_comprehension); i.e. only apply
NameOp::Fast when that “inlined comprehension active” predicate is true so the
fast_hidden entry on the enclosing code object does not leak to subsequent
top-level/class code.

In `@crates/codegen/src/ir.rs`:
- Around line 2245-2254: The cloned instructions t0/t1 are having their location
fields updated but not their lineno_override, so inlined LOAD_CONST/RETURN_VALUE
can retain the target block's override (e.g., -1); update the clones (load and
ret) to copy ins.lineno_override (and, if present, any related
end_lineno_override semantics) from the jump instruction before pushing into
replacements so the inlined return reports the jump site line number.
- Around line 1480-1511: The new combine_store_fast_load_fast optimization is
never run because finalize_code() doesn't call it; update finalize_code() to
invoke combine_store_fast_load_fast() (placed after optimize_load_fast_borrow()
to preserve the intended ordering so STORE_FAST + LOAD_FAST_BORROW pairs aren't
combined) so the STORE_FAST_LOAD_FAST opcode becomes live and affects emitted
bytecode.

In `@crates/codegen/src/symboltable.rs`:
- Around line 2172-2181: The comp inlining decision sets
self.tables.last_mut().unwrap().comp_inlined = true too early because it only
checks element_has_await from elt1/elt2; move all await checks into a single
pre-check before that assignment: use expr_contains_await over elt1/elt2, all
if-clauses (ifs), and every generator iterable expression (the same expressions
later scanned around the existing logic), combine them into a single boolean
(e.g., any_await_in_comprehension) and include it in the gate alongside
is_generator and has_async_gen; ensure the code references expr_contains_await,
elt1, elt2, the ifs and generator iterable expressions and only sets
comp_inlined when no await is found.

In `@scripts/dis_dump.py`:
- Around line 82-96: The current argrepr normalization mutates real string
literal reprs; update the logic around the substitutions that touch argrepr (the
two " + NULL" removals and the two re.sub calls that unescape \\u/\\U and the at
0x removal) to skip these rewrites when argrepr is itself a quoted Python
literal: detect quoted reprs with a regex like ^[rubfRUBF]*(['"])(.*)\1$ (or
similar) and if it matches, do not apply the address/NULL/unescape rewrites;
keep the existing _unescape helper and substitutions but only call them when
argrepr is not a string literal.
- Around line 294-307: The results dict in scripts/dis_dump.py uses non-unique
keys (relpath or basename) causing collisions when multiple targets are passed;
modify the keying logic around the loop that calls process_file so keys include
the input target context (e.g., prefix relpath with a unique identifier derived
from the target such as the target root name or absolute path, or use a tuple
key like (target, relpath)) and apply the same scheme for single-file branches
(replace os.path.basename(target) with the same unique-key format) so entries
from different input targets cannot overwrite each other.

---

Duplicate comments:
In `@crates/codegen/src/compile.rs`:
- Around line 3884-3899: The StopIteration wrapper is only applied around
compile_function_body(), so generator expressions and async comprehensions
created in compile_comprehension() can still leak StopIteration; update
compile_comprehension() to detect generator/coroutine code objects (same
condition used: is_async || self.current_symbol_table().is_generator) and wrap
their body creation with the same SetupCleanup +
push_fblock(FBlockType::StopIteration, handler_block, handler_block) pattern
(creating handler_block via new_block(), emit PseudoInstruction::SetupCleanup
with that block, call set_no_location(), and push_fblock), mirroring the
stop_iteration_block logic used around compile_function_body() so StopIteration
is always converted to StopIterationError for comprehension-created code objects
(also apply the same change at the analogous location referenced around lines
3931-3946).
- Around line 8831-8834: Dead code suppression via do_not_emit_bytecode
currently only stops _emit but still lets metadata writers and some emit sites
(e.g., arg_constant(), _name_inner(), emit_resume_for_scope()) mutate
co_consts/co_names and nested code objects; update those writers and bypassing
sites to respect the same guard. Specifically, add an early-return check that
consults do_not_emit_bytecode (or a new helper like should_emit_metadata()) at
the start of arg_constant, _name_inner, emit_resume_for_scope and any other
metadata-mutating helpers so they do not modify co_consts/co_names or create
nested code objects when do_not_emit_bytecode > 0. Ensure the helper is used
consistently across all metadata writers instead of only in _emit.
- Line 9064: The match arm handling ast::Expr::Tuple currently returns
Some(!elts.is_empty()) which incorrectly treats any non-empty tuple as
unconditionally truthy; change it to only fold to true when every element is a
compile-time constant by replacing the unconditional check with a per-element
constant check (e.g., elts.iter().all(|e| <existing_const_check>(e))). Update
the ast::Expr::Tuple(ast::ExprTuple { elts, .. }) => branch to call the
project’s const-fold/const-detect helper (such as expr_is_const or
constant_foldable) on each elt and return Some(true) only if all elements are
constant, otherwise return None.
- Around line 5234-5241: When constant == Some(true) the code currently skips
compiling later clause tests entirely; instead ensure clause tests still run
under bytecode suppression so validations (like await-outside-async) and scope
consumption occur. Change the loop over elif_else_clauses so you increment
do_not_emit_bytecode, compile each clause's test/condition (compile the test
expression) and then compile the clause.body under suppression, then decrement
do_not_emit_bytecode; i.e., move the suppression (do_not_emit_bytecode += 1 / -=
1) to cover both the clause test and body rather than skipping the test entirely
while only skipping the body (refer to elif_else_clauses, compile_statements,
and the do_not_emit_bytecode flag).

In `@crates/codegen/src/ir.rs`:
- Around line 788-799: The constant-folding arms for BinOp::FloorDivide and
BinOp::Remainder currently use Rust's raw / and % which produce incorrect
results for negative operands; replace those raw operators with the same
Python-compatible helpers used at runtime: call the integer helpers (div_floor
and mod_floor from the int builtins) when folding integer operands, and the
float helpers (floordiv and/or mod_ in crates/common/src/float_ops.rs) for
floating-point operands, preserving the zero-checks and returning None on
divide-by-zero; update the BinOp::FloorDivide and BinOp::Remainder match arms to
dispatch to those helper functions instead of using l / r or l % r.
- Around line 193-196: The binop constant folding pass needs to run one more
time after unary-negative folding so expressions like `-1 + 2` and `2 * -3` get
folded; update the sequence in the IR pass to call fold_binop_constants() again
after fold_unary_negative() (i.e., keep the existing initial
fold_binop_constants(); remove_nops(); fold_unary_negative(); remove_nops();
then invoke fold_binop_constants() a second time) so the binop pass sees
LOAD_CONST produced by fold_unary_negative().

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@crates/codegen/src/compile.rs`:
- Around line 7484-7489: The fast-path for format-string optimization
incorrectly runs when the RHS tuple contains starred elements (e.g., "%s" %
(*xs,)), causing Starred to be compiled as a plain expression; update the match
that checks ast::Expr::Tuple in compile.rs so it only takes the fast-path when
the tuple's elements contain no Starred nodes (e.g., require elts.iter().all(|e|
!matches!(e, ast::Expr::Starred(_)))); keep the call to
try_optimize_format_str(...) and short-circuit the optimization when any starred
element is present.

In `@crates/vm/src/stdlib/_symtable.rs`:
- Around line 177-179: Filtering out items with comp_inlined currently discards
entire subtrees (hiding valid descendant symbol tables); instead, when building
the list (where you now do .filter(|t| !t.comp_inlined).map(|t|
to_py_symbol_table(t.clone()).into_pyobject(vm)).collect()), replace that
pipeline with a flat-mapping step that yields the node itself when comp_inlined
is false, but when comp_inlined is true yields its non-inlined descendants (or
recursively yields grandchildren) and then call to_py_symbol_table on those
actual nodes; in short, preserve/flatten children of nodes where comp_inlined ==
true rather than dropping the whole t so symtable.children includes nested
non-inlined scopes.

---

Duplicate comments:
In `@crates/codegen/src/compile.rs`:
- Around line 5202-5288: Dead branches still mutate code-object metadata because
helper routines (emit_load_const, _name_inner, make_closure) intern
constants/names or register nested code objects even when do_not_emit_bytecode
is set; change those helpers to early-return or take a no-op path when
self.do_not_emit_bytecode > 0 so they do not mutate live metadata (e.g., in
emit_load_const check self.do_not_emit_bytecode and skip interning/emission, in
_name_inner avoid adding names to tables, and in make_closure avoid registering
the nested code object), or alternatively make them append into the current
sub_table only (not the live code object) when do_not_emit_bytecode is active;
update compile_if/compile_while callers only if needed to ensure
do_not_emit_bytecode is set before any of these helpers run.
- Around line 3877-3939: The comprehension compiler (compile_comprehension) must
apply the same PEP-479 generator/coroutine wrapping as compile_function_body:
detect generator/async-comprehension, create a handler_block via
self.new_block(), emit PseudoInstruction::SetupCleanup { delta: handler_block },
call self.set_no_location() and self.push_fblock(FBlockType::StopIteration,
handler_block, handler_block) before compiling the comprehension body, and after
compiling emit PseudoInstruction::PopBlock, self.set_no_location(),
self.pop_fblock(FBlockType::StopIteration), self.switch_to_block(handler_block),
then emit Instruction::CallIntrinsic1 { func:
oparg::IntrinsicFunction1::StopIterationError } followed by Instruction::Reraise
{ depth: 1u32 } (with set_no_location() calls as in compile_function_body) so
StopIteration cannot escape pre-PEP-479 in generator/async comprehensions.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@crates/vm/src/frame.rs`:
- Around line 9462-9464: The code creates a fresh RuntimeError via
vm.new_runtime_error and sets __cause__ from arg.downcast() but loses the
original traceback, so wrap of StopIteration will drop the originating frame;
change the construction to preserve the original exception's traceback by
extracting the traceback from the original exception (arg.downcast()) and
attaching it to the new error before returning (e.g., set the new error's
__traceback__ from the original exception's __traceback__), keeping the existing
err.set___cause__(...) logic so __cause__ and __traceback__ are both preserved;
refer to vm.new_runtime_error, err.set___cause__, arg.downcast(), and the
surrounding Reraise/Instruction::Reraise handling in ExecutingFrame::run when
making the fix.