PRINCIPLES OF COMPILER DESIGN Syllabus:

Syllabus:

PRINCIPLES OF COMPILER DESIGN

L T P

3 1 0

UNIT I           INTRODUCTION TO COMPILING                                                        9

Compilers − Analysis of the source program − Phases of a compiler − Cousins of the compiler − Grouping of phases − Compiler construction tools − Lexical analysis − Role of lexical analyzer − Input buffering − Specification of tokens.

UNIT II          SYNTAX ANALYSIS                                                                                 9

Role of the parser − Writing grammars − Context-free grammars − Top down parsing − Recursive descent parsing − Predictive parsing − Bottom-up parsing − Shift reduce parsing − Operator precedence parsing − LR parsers − SLR parser − Canonical LR parser − LALR parser.

UNIT III        INTERMEDIATE CODE GENERATION                                              9

Intermediate languages − Declarations − Assignment statements − Boolean expressions −

Case statements − Back patching − Procedure calls.

PRINCIPLES OF COMPILER DESIGN

Principles of compiler design

16 Marks

1.       Construct the CLRparsing for the accepting state (id+id) and not accepting state id+?

2.       Explain the predictive parsing with an example?

3.       For the given grammar G and the input string (id*id), do the shift-reduce parsing?

4.       Explain the implementation of Three address codes?

5.       Explain translation of boolean expressions in detail?

6.       Explain translation of declaration?

2-Marks

COMPUTER NETWORKS QUESTIONS AND ANSWERS - VI

UNIT-V

1. What is the function of SMTP?

The TCP/IP protocol supports electronic mail on the Internet is called Simple Mail Transfer (SMTP). It is a system for sending messages to other computer users based

on e-mail addresses. SMTP provides mail exchange between users on the same or different computers.

2. What is the difference between a user agent (UA) and a mail transfer agent (MTA)?

            The UA prepares the message, creates the envelope, and puts the message in the envelope. The MTA transfers the mail across the Internet.

3. How does MIME enhance SMTP?

            MIME is a supplementary protocol that allows non-ASCII data to be sent through SMTP. MIME transforms non-ASCII data at the sender site to NVT ASCII data and deliverers it to the client SMTP to be sent through the Internet. The server SMTP at the receiving side receives the NVT ASCII data and delivers it to MIME to be transformed back to the original data.

4. Why is an application such as POP needed for electronic messaging?

Workstations interact with the SMTP host, which receives the mail on behalf of every host in the organization, to retrieve messages by using a client-server protocol such as Post Office Protocol, version 3(POP3). Although POP3 is used to download messages from the server, the SMTP client still needed on the desktop to forward messages from the workstation user to its SMTP mail server.

COMPUTER NETWORKS QUESTIONS AND ANSWERS - I

PART B

UNIT  I

1. Explain in detail the error detection and error corrections.(UQ)
2. Discuss in detail about the layers of OSI model. (UQ)
3. Discuss in detail about HDLC.
4. Discuss in detail about SONET.
5. Explain the different approaches of framing in detail.
6. Write the Sliding Window Algorithm and explain it in detail.
7. Compare Stop and Wait ARQ scheme with sliding window ARQ scheme.
8. Write in detail about the flow control mechanisms.

UNIT II

COMPUTER NETWORKS QUESTIONS AND ANSWERS - V

UNIT-IV

1. Explain the main idea of UDP?

             The basic idea is for a source process to send a message to a port and for the destination process to receive the message from a port.

2. What are the different fields in pseudo header?

·       Protocol number

·       Source IP address

·       Destination IP addresses.

3. Define TCP?

               TCP guarantees the reliable, in order delivery of a stream of bytes. It is a full-duplex protocol, meaning that each TCP connection supports a pair of byte streams, one flowing in each direction.

4. Define Congestion Control?

               It involves preventing too much data from being injected into the network, thereby causing switches or links to become overloaded. Thus flow control is an end to an end issue, while congestion control is concerned with how hosts and networks interact.

5. State the two kinds of events trigger a state transition?

·       A segment arrives from the peer.

·       The local application process invokes an operation on TCP.

6. What is meant by segment?

               At the sending and receiving end of the transmission, TCP divides long transmissions into smaller data units and packages each into a frame called a segment.

7.  What is meant by segmentation?

               When the size of the data unit received from the upper layer is too long for the network layer datagram or data link layer frame to handle, the transport protocol divides it into smaller usable blocks. The dividing process is called segmentation.

8. What is meant by Concatenation?

              The size of the data unit belonging to single sessions are so small that several can fit together into a single datagram or frame, the transport protocol combines them into a single data unit. The combining process is called concatenation.

9. What is rate based design?

            Rate- based design, in which the receiver tells the sender the rate-expressed in either bytes or packets per second – at which it is willing to accept incoming data.

10. Define Gateway.

A device used to connect two separate networks that use different communication protocols.

11. What is meant by quality of service?

            The quality of service defines a set of attributes related to the performance of the connection. For each connection, the user can request a particular attribute each service class is associated with a set of attributes.

12.  What are the two categories of QoS attributes?

            The two main categories are,

·       User Oriented

·       Network Oriented

13.  List out the user related attributes?

            User related attributes are SCR – Sustainable Cell Rate PCR – Peak Cell Rate MCR- Minimum Cell Rate CVDT – Cell Variation Delay Tolerance.

14. What are the networks related attributes?

The network related attributes are, Cell loss ratio (CLR) Cell transfer delay (CTD) Cell delay variation (CDV) Cell error ratio (CER).    

15. What is RED?

            Random Early Detection in each router is programmed to monitor its own queue length and when it detects that congestion is imminent, to notify the source to adjust its congestion window.

16. What are the three events involved in the connection?

          For security, the transport layer may create a connection between the two end ports. A connection is a single logical path between the source and destination that is associated with all packets in a message. Creating a connection involves three steps:

·       Connection establishment

·       Data transfer

·        Connection release