swiftlang/swift

[SR-340] Refactor SILParser::parseSILInstruction

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#42,962 opened on Dec 22, 2015

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 (7 comments) (0 reactions) (1 assignee)Swift (69,989 stars) (10,719 forks)batch import
SILParsercompilergood first issuenfc

Description
Previous ID SR-340
Radar None
Original Reporter @gottesmm
Type Bug
Status In Progress
Resolution
Votes 1
Component/s Compiler
Labels Bug, StarterBug
Assignee d066z (JIRA)
Priority Medium

md5: ee6df5ef735c9655c56ca6ce06200e7e

Issue Description:

parseSILInstruction is horrible and makes me cry every time I see it. It is a method that is ~1900 lines with a huge switch in it. We should refactor it into a visitor structure. In fact it is large enough that we should consider moving it into its own file if it is possible.

Contributor guide

Tech stack
swift
Domain
backend
Issue type
refactor
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
SIL basicsVisitor patternSwift compiler structure
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Examine the current implementation of parseSILInstruction in the SILParser file (likely in lib/SIL/SILParser.cpp). Understand the huge switch statement and how it dispatches to different SIL instructions. Research existing visitor patterns in the Swift compiler, such as the SILInstructionVisitor. Propose a refactored structure with multiple visitor classes, each handling a subset of instructions, and consider moving the code to a separate file. Review any comments from the assignee for guidance.