Linkage Check Steps

1. Get Class Path

A class path is List<ClassPathEntry>.

ClassPathEntry:
  Path jar
  Artifact artifact (optional)

2. Get References

LinkageChecker builds SymbolReferenceMaps:

SymbolReferenceMaps:
  Multimap<ClassFile, ClassSymbol>  classToClassSymbols;
  Multimap<ClassFile, MethodSymbol> classToMethodSymbols;
  Multimap<ClassFile, FieldSymbol>  classToFieldSymbols;

3. Validate the References

Linkage Checker validates the references to get Linkage Errors.

Linkage errors are Multimap<SymbolProblem, ClassFile>

SymbolProblem:
  Symbol  symbol  (ClassSymbol, MethodSymbol, or FieldSymbol)
  ClassFile containingClass  (nullable)
  ErrorType errorType

ClassFile:
  ClassPathEntry classPathEntry
  String binaryName