jasder
/
antlr
1
0
Fork 1
Code Issues Pull Requests Releases 1 Wiki Activity

work around Swift crash where reading hashValue on SemanticContext.AND instance would call the empty constructor (possibly a Swift bug?)

This commit is contained in:
Eric Vergnaud 2021-01-24 13:46:58 +08:00
parent b050ac43de
commit 020333deff
1 changed files with 21 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
runtime/Swift/Sources/Antlr4/atn/LookupDictionary.swift
View File

@ -28,13 +28,27 @@ public struct LookupDictionary {
private func hash(_ config: ATNConfig) -> Int {
if type == LookupDictionaryType.lookup {
/* migrating to XCode 12.3/Swift 5.3 introduced a very weird bug
where reading hashValue from a SemanticContext.AND instance woul:
call the AND empty constructor
NOT call AND.hash(into)
Could it be a Swift compiler bug ?
All tests pass when using Hasher.combine()
Keeping the old code for reference:
var hashCode: Int = 7
hashCode = 31 * hashCode + config.state.stateNumber
hashCode = 31 * hashCode + config.alt
hashCode = 31 * hashCode + config.semanticContext.hashValue
hashCode = 31 * hashCode + config.semanticContext.hashValue // <- the crash would occur here
return hashCode
*/
var hasher = Hasher()
hasher.combine(7)
hasher.combine(config.state.stateNumber)
hasher.combine(config.alt)
hasher.combine(config.semanticContext)
return hasher.finalize()
} else {
//Ordered
return config.hashValue