Class CodeGenerator

rhino/src/main/java/org/mozilla/javascript/CodeGenerator.java:23–2027

Generates bytecode for the Interpreter.

/** Generates bytecode for the Interpreter. */
class CodeGenerator<T extends ScriptOrFn<T>> {

    private static final int MIN_LABEL_TABLE_SIZE = 32;
    private static final int MIN_FIXUP_TABLE_SIZE = 40;

    private CompilerEnvirons compilerEnv;

    private boolean itsInFunctionFlag;
    private boolean itsInTryFlag;

    private InterpreterData.Builder<T> itsData;
    private JSDescriptor.Builder<T> builder;

    private ScriptNode scriptOrFn;
    private int iCodeTop;
    private int stackDepth;
    private int lineNumber = -1;
    private int doubleTableTop;

    private final HashMap<String, Integer> strings = new HashMap<>();
    private final HashMap<BigInteger, Integer> bigInts = new HashMap<>();
    private int localTop;
    private int[] labelTable;
    private int labelTableTop;

    // fixupTable[i] = (label_index << 32) | fixup_site
    private long[] fixupTable;
    private int fixupTableTop;
    private final ArrayList<Object> literalIds = new ArrayList<>();

    private int exceptionTableTop;

    // ECF_ or Expression Context Flags constants: for now only TAIL
    private static final int ECF_TAIL = 1 << 0;

    public JSDescriptor<T> compile(
            CompilerEnvirons compilerEnv,
            ScriptNode tree,
            String rawSource,
            boolean returnFunction) {
        this.compilerEnv = compilerEnv;

        if (Token.printTrees) {
            System.out.println("before transform:");
            System.out.println(tree.toStringTree(tree));
        }

        new NodeTransformer().transform(tree, compilerEnv);

        if (Token.printTrees) {
            System.out.println("after transform:");
            System.out.println(tree.toStringTree(tree));
        }

        if (returnFunction) {
            scriptOrFn = tree.getFunctionNode(0);
        } else {
            scriptOrFn = tree;