fix: #2016 - Generate correct iGo code for lists in a grammar, such a…

[jimidle]

fix: #2016 Generate the correct Go code for label+=arg+ in a grammar

Signed-off-by: Jim.Idle jimi@gatherstars.com

[KvanTTT]

A test is missing.

[jimidle]

I agree but I see no way to add a test for this Please add if you see a way.

…

On Tue, Aug 23, 2022 at 17:36 Ivan Kochurkin ***@***.***> wrote: A test is missing. — Reply to this email directly, view it on GitHub <#3834 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAJ7TMAN74CO53EOT7LSUA3V2SLS3ANCNFSM57J2GQVQ> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[KvanTTT]

We use descriptor files for runtime tests, see antlr-project-testing.md. You can skip other runtimes using [skip] flag but in general it's not recommended.

I added ListLabelInsideClosure.txt, but it fails on the execution step, see https://github.com/antlr/antlr4/runs/7982817143?check_suite_focus=true#step:23:1987

Test: ListLabelInsideClosure; State: Execute; java.lang.InterruptedException: 
panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext [recovered]
	panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext

goroutine 1 [running]:
test/parser.(*TestParser).r.func2()
	/tmp/GoRunner-ForkJoinPool-1-worker-1-1661288428057/parser/test_parser.go:280 +0xfe
panic({0x4e0900, 0xc00008d200})
	/opt/hostedtoolcache/go/1.19.0/x64/src/runtime/panic.go:884 +0x212
github.com/antlr/antlr4/runtime/Go/antlr.merge({0x52f9f0?, 0xc0000a0940}, {0x52faa0?, 0xc000098038}, 0x0, 0x52fe68?)
	/home/runner/work/antlr4/antlr4/runtime/Go/antlr/prediction_context.go:407 +0x351
github.com/antlr/antlr4/runtime/Go/antlr.(*BaseATNConfigSet).Add(0xc00009e680, {0x52fe68?, 0xc0000ca230}, 0x0?)
	/home/runner/work/antlr4/antlr4/runtime/Go/antlr/atn_config_set.go:140 +0x21f
github.com/antlr/antlr4/runtime/Go/antlr.(*ParserATNSimulator).closureWork(0xc00009a1e0, {0x52fe68, 0xc0000ca230}, {0x530f38, 0xc00009e680}, 0xc0000c4b78?, 0x0, 0xbc?, 0xffffffffffffffff, 0x0)
...
	/home/runner/work/antlr4/antlr4/runtime/Go/antlr/parser_atn_simulator.go:145 +0xbef
test/parser.(*TestParser).r(0xc000098168, 0xc00009e180?)
	/tmp/GoRunner-ForkJoinPool-1-worker-1-1661288428057/parser/test_parser.go:296 +0x2dd
test/parser.(*TestParser).R(...)
	/tmp/GoRunner-ForkJoinPool-1-worker-1-1661288428057/parser/test_parser.go:254
main.main()
	/tmp/GoRunner-ForkJoinPool-1-worker-1-1661288428057/Test.go:37 +0x15c
exit status 2
Test directory: /tmp/GoRunner-ForkJoinPool-1-worker-1-1661288428057

In fact, the bug is not fixed.

[chenquan]

I found this problem in github.com/antlr/antlr4/runtime/Go/antlr v1.4.10. grammar:https://github.com/antlr/grammars-v4/tree/master/sql/mysql/Positive-Technologies

out:

panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext [recovered]
	panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext [recovered]
	panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext

[jimidle]

Thanks for the report. I will get this fixed in @dev

…

On Sun, Oct 16, 2022 at 20:37 chen quan ***@***.***> wrote: I found this problem in github.com/antlr/antlr4/runtime/Go/antlr v1.4.10. grammar: https://github.com/antlr/grammars-v4/tree/master/sql/mysql/Positive-Technologies [image: image] <https://user-images.githubusercontent.com/20548053/196035594-20e31da3-67e0-422f-967b-ac96245d9a5c.png> out: panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext [recovered] panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext [recovered] panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext — Reply to this email directly, view it on GitHub <#3834 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAJ7TMATD5372PKS5NCGO33WDPZHXANCNFSM57J2GQVQ> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[jimidle]

@parrt @KvanTTT - I cannot reproduce this with the latest runtime code. I have some recollection of fixing this as part of some other code fix, but I cannot be sure. Code should refer to the PredictionContext interface rather than a specific instance.

But I believe that I fixed this as a byproduct of changing the code that callsmergeArrays, many months ago. It was due to the fact that the "inheritance" was being implemented in PredictionContext was FUBAR and now it is not.

I think that we can close this. I have verified that it all works at both codegen and runtime