问如何将ANTLR生成的AST转换为源代码

EN

void  printTree(pANTLR3_BASE_TREE t, int indent) 
{
    pANTLR3_BASE_TREE child = NULL;
    int     children = 0;
    char *  tokenText = NULL;
    string  ind = "";
    int     i = 0;

    if ( t != NULL ) 
      {
        children = t->getChildCount(t);
        for ( i = 0; i < indent; i++ )
          ind += "   ";

        for ( i = 0; i < children; i++ )
          {
            child = (pANTLR3_BASE_TREE)(t->getChild(t, i));
            tokenText = (char *)child->toString(child)->chars;
            fprintf(stderr, "%s%s\n", ind.c_str(), tokenText);
            if (tokenText == "<EOF>")
              break;
            printTree(child, indent+1);
          }
      }
}


// Run the parser
pANTLR3_BASE_TREE langAST = (psr->start_rule(psr)).tree; 

// Print the AST
printTree(langAST, 0);

// Get the Parser Errors
int nErrors = psr->pParser->rec->state->errorCount;