[Patterns] Cumulative fixes for various problems

[srikanth-sankaran]

What it does

• Fixes [Patterns] [Whitebox] Redundant calls to org.eclipse.jdt.internal.compiler.codegen.CodeStream.addVisibleLocalVariable(LocalVariableBinding) #1889
• Fixes [Patterns] Design smell: Pattern classes are far from object oriented #1986
• Fixes [Switch][Pattern] Withdraw the internal AST APIs Pattern.suspendVariables & Pattern.resumeVariables #2019
• Fixes [Patterns][internal] toString() output of AST nodes shows up with modifier sealed for pattern variables #2017
• Fixes [Patterns][internal] High degree of code duplication in instanceof pattern code generation #2021
• Fixes [Patterns][Unnamed] Wasteful allocation and assignment into unnamed pattern variables. #2020
• Fixes [Patterns][records] ECJ fails to reject incompatible pattern types. #2001
• Fixes [Patterns][records] Instanceof with record deconstruction patterns should never be flagged as unnecessary #1999
• Fixes [20][pattern switch] unnecessary code generated #773
• Fixes [Patterns][internal] It doesn't make sense for org.eclipse.jdt.internal.compiler.ast.RecordPattern to extend TypePattern #2043
• Fixes [Patterns] Suggest identifier completion for obj instanceof Dog #92
• Fixes [Patterns][smell] {TypePattern/RecordPattern/GuardedPattern}.resolveType should not be reentered #2044
• Fixes https://bugs.eclipse.org/bugs/show_bug.cgi?id=575070
• Fixes [Pattern] Grammar file references impossible and nop reduce action methods #2045
• Fixes [Switch][Patterns] ECJ incorrectly holds a record pattern "guarded by when true" as being unconditional for the switch expression type #2053
• Fixes [Patterns][records][inference] ECJ never computes the upwards projection for var type inference in record patterns #2007
• Fixes JEP 443: lists of patterns as a case label #1643
• Fixes [22] JEP 456: Unnamed Variables & Patterns #1595
• Fixes [Patterns][Java22] Abstraction gap in modelling multi case patterns #2069
• Fixes [Patterns] Incorrect complaint about non-final variable reference from guard expression #2077
• Fixes StackOverflowException in XLargeTest#test011() #1171

How to test

Author checklist

• I have thoroughly tested my changes
• The change is following the coding conventions
• I have signed the Eclipse Contributor Agreement (ECA)

[mpalat]

+1
merge please

[mpalat]

sorry - approved by mistake -
will wait until it is fully ready

[srikanth-sankaran]

Hello David (@datho7561) - I am mostly done with cleaning up the pattern matching implementation. This branch contains a bunch of fixes that were late for 4.31 and so are being accumulated here. Once master opens for 4.32 development, (March 2nd) I will merge these in.

The most recent two commits concern your past work - you are welcome to review them and report any problems. I invite you to review all the changes not just those two commit if time permits. If you want to continue your work on #1742 - you will have to study Pattern.java, TypePattern.java, RecordPattern.java, GuardedPattern.java and InstanceofExpression.java - things have changed a whole lot since the time you worked on unnamed patterns.

Where are you on #1742 ?? If you are able to bring it up to date with this branch (not master), I can look into absorbing it. Is that PR fully functional ? What is missing if anything ?

[datho7561]

I'll spend some time rebasing that PR onto this one. Most of my changes for the parsing aspect shouldn't cause conflicts. I'll need to add my code generation changes, and that's where the conflicts will be. I think your refactoring will make the code generation code simpler.

[srikanth-sankaran]

Hi David (@datho7561) the most recent commit made for #2044 may impact you too - but should be in a good way overall.