boolean checkIsValid() {
		if (function.isDeleted()) {
			return false;
		}
		if (invalid) {
			stackGrowsNegative =
				function.getFunctionManager().getProgram().getCompilerSpec().stackGrowsNegative();
			variables = function.getVariables(VariableFilter.COMPOUND_STACK_VARIABLE_FILTER);
			Arrays.sort(variables, StackVariableComparator.get());
			invalid = false;
		}
		return true;
	}
Construct a function stack frame.
@param function
@param variables
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/function/FunctionStackFrame.java