/**
* Compile or interpret a Pascal source program.
*
* @param operation either "compile" or "execute".
* @param filePath the source file path.
* @param flags the command line flags.
*/
public Pascal(String operation, String sourcePath, String inputPath, String flags) {
try {
intermediate = flags.indexOf('i') > -1;
xref = flags.indexOf('x') > -1;
source = new Source(new BufferedReader(new FileReader(sourcePath)));
source.addMessageListener(new SourceMessageListener());
parser = FrontendFactory.createParser("Pascal", "top-down", source);
parser.addMessageListener(new ParserMessageListener());
backend = BackendFactory.createBackend(operation, inputPath);
backend.addMessageListener(new BackendMessageListener());
parser.parse();
source.close();
if (parser.getErrorCount() == 0) {
symTabStack = parser.getSymTabStack();
SymTabEntry programId = symTabStack.getProgramId();
iCode = (ICode) programId.getAttribute(ROUTINE_ICODE);
if (xref) {
CrossReferencer crossReferencer = new CrossReferencer();
crossReferencer.print(symTabStack);
}
if (intermediate) {
ParseTreePrinter treePrinter = new ParseTreePrinter(System.out);
treePrinter.print(symTabStack);
}
backend.process(iCode, symTabStack);
}
} catch (Exception ex) {
System.out.println("***** Internal translator error. *****");
ex.printStackTrace();
}
}
private ICodeNode parseIdentifier(Token token) throws Exception {
ICodeNode rootNode = null;
// Look up the identifier in the symbol table stack.
// Flag the identifier as undefined if it's not found.
String name = token.getText().toLowerCase();
SymTabEntry id = symTabStack.lookup(name);
// Undefined.
if (id == null) {
errorHandler.flag(token, IDENTIFIER_UNDEFINED, this);
id = symTabStack.enterLocal(name);
id.setDefinition(UNDEFINED);
id.setTypeSpec(Predefined.undefinedType);
}
Definition defnCode = id.getDefinition();
switch ((DefinitionImpl) defnCode) {
case CONSTANT:
{
Object value = id.getAttribute(CONSTANT_VALUE);
TypeSpec type = id.getTypeSpec();
if (value instanceof Integer) {
rootNode = ICodeFactory.createICodeNode(INTEGER_CONSTANT);
rootNode.setAttribute(VALUE, value);
} else if (value instanceof Float) {
rootNode = ICodeFactory.createICodeNode(REAL_CONSTANT);
rootNode.setAttribute(VALUE, value);
} else if (value instanceof String) {
rootNode = ICodeFactory.createICodeNode(STRING_CONSTANT);
rootNode.setAttribute(VALUE, value);
}
id.appendLineNumber(token.getLineNumber());
token = nextToken(); // consume the constant identifier
if (rootNode != null) {
rootNode.setTypeSpec(type);
}
break;
}
case ENUMERATION_CONSTANT:
{
Object value = id.getAttribute(CONSTANT_VALUE);
TypeSpec type = id.getTypeSpec();
rootNode = ICodeFactory.createICodeNode(INTEGER_CONSTANT);
rootNode.setAttribute(VALUE, value);
id.appendLineNumber(token.getLineNumber());
token = nextToken(); // consume the enum constant identifier
rootNode.setTypeSpec(type);
break;
}
case FUNCTION:
{
CallParser callParser = new CallParser(this);
rootNode = callParser.parse(token);
break;
}
default:
{
VariableParser variableParser = new VariableParser(this);
rootNode = variableParser.parse(token, id);
break;
}
}
return rootNode;
}