private boolean processDuplicateExternal(ElfSymbol elfSymbol) {
		if (lastExternalBlockEntryAddress == null) {
			return false;
		}
		String symName = elfSymbol.getNameAsString();
		if (StringUtils.isBlank(symName)) {
			return false;
		}
		Symbol s = findExternalBlockSymbol(symName, externalBlockLimits.getMinAddress(),
			lastExternalBlockEntryAddress);
		if (s != null) {
			// NOTE: re-use of other fake external address does not support
			// data allocation.  It may be necessary to ensure that dynamic 
			// symbol table is processed last.
			setElfSymbolAddress(elfSymbol, s.getAddress());
			return true;
		}
		return false;
	}
Determine if an external ELF symbol has already been established with the
same name and re-use it.
@param elfSymbol external ELF symbol
@return true if processed as a duplicate external symbol and no additional 
processing is required, else false
Ghidra/Features/Base/src/main/java/ghidra/app/util/opinion/ElfProgramBuilder.java