Remove JUMP_IF_NOT_EXC_MATCH, SET_EXC_INFO by youknowone · Pull Request #6820 · RustPython/RustPython

youknowone

📝 Walkthrough

Walkthrough

This PR refactors exception handling bytecode by removing JumpIfNotExcMatch and SetExcInfo opcodes. Exception matching logic is consolidated into CheckExcMatch, which now sets the matched exception as current, while PopJumpIfFalse replaces JumpIfNotExcMatch for conditional jumps. The bytecode instruction enum and related dispatch paths are simplified accordingly.

Changes

Cohort / File(s)	Summary
Instruction variants removal `crates/compiler-core/src/bytecode/instruction.rs`	Removed public enum variants `JumpIfNotExcMatch(Arg<Label>)` and `SetExcInfo` from `Instruction`. Removed their handling from `TryFrom<u8>`, `InstructionMetadata` (label_arg, stack_effect, fmt_dis), and formatting/disassembly paths.
Code generation updates `crates/codegen/src/compile.rs`	Replaced duplicated exception-copy sequence with inline `CheckExcMatch` and `PopJumpIfFalse` for per-handler exception matching. Removed `SetExcInfo` emission since `CheckExcMatch` now sets the matched exception as current.
VM execution logic `crates/vm/src/frame.rs`	Removed implementations of `Instruction::JumpIfNotExcMatch` and `Instruction::SetExcInfo`. Enhanced `CheckExcMatch` with BaseException inheritance validation. Updated `CHECK_EG_MATCH` to set VM's current exception to matched exception after `exception_group_match`.
Opcode classification `crates/stdlib/src/opcode.rs`	Removed `JumpIfNotExcMatch` from `has_jump()` match arms, narrowing the set of jump-classified instructions.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

Sort Instruction enum & related match arms #6322: Directly modifies the same bytecode instruction surface with exception handling and CheckExcMatch-based logic.
Split TestOperator instruction #6306: Directly reverses or modifies the same exception-match machinery including JumpIfNotExcMatch and SetExcInfo handling.
New Instruction ToBool,PopJumpIfFalse #6112: Related through codegen changes that emit PopJumpIfFalse for conditional jumps in compile.rs.

Suggested reviewers

ShaharNaveh

Poem

🐰 With CheckExcMatch we hop more true,
SetExcInfo and JumpIfNot—adieu!
PopJumpIfFalse now bears the load,
Exception paths on cleaner road! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly and specifically describes the main change: removal of two instruction variants (JUMP_IF_NOT_EXC_MATCH and SET_EXC_INFO) from the codebase, which is clearly reflected across all modified files.

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✨ Finishing touches

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