private void setProgramCounter(String programCounterName) {
		if (programCounterName == null) {
			return;
		}

		Register reg = registerBuilder.getRegister(programCounterName);

		if (reg == null) {
			Msg.error(this, "unknown program counter register " + programCounterName + ": " +
				description.getSpecFile());
			return;
		}
		registerBuilder.setFlag(programCounterName, Register.TYPE_PC);
		programCounter = reg;
	}
Returns the source file indexer
@return indexer
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/processors/sleigh/SleighLanguage.java