1. Chapter 10 Application Development

2. Chapter 10 Application Development
Chapter Outline
The Application Development Process
Programming Languages
Compilation
Link Editing
Interpreters
Focus - Java
Symbolic Debugging
Integrated Application Development Tools
Focus – Oracle JDeveloper
Focus - Building the Next Generation of Application Software

3. Chapter Goals
Describe the application development process and the role of methodologies, models, and tools
Compare and contrast programming language generations
Explain the function and operation of program translation software, including assemblers, compilers, and interpreters
Describe link editing, and contrast static and dynamic linking
Describe integrated application development software, including programmer’s workbenches and CASE tools

4. Chapter 10 Application Development

5. The Application Development Process
Follows a development methodology
Develops a set of models
Uses automated tools

6. Application Development

7. Systems Development Life Cycle (SDLC)
Follow disciplines and iterations of the Unified Process (UP)
Usually includes two sets of models
System requirements model
Design model

8. The Unified Process (UP)

9. Methodologies and Models
Methodology
Integrated collection of models, tools, and techniques
UP employs object-oriented analysis, design, and deployment models
Class diagrams document user and system requirements

10. Tools
Wide array to support or completely automate software development tasks
Proper tool selection is a critical and difficult undertaking

11. This Material Continued In
CIS 242 Introduction to Systems Analysis and Design 4 hours, 4 credits
Study of a computer system life cycle via a structured approach: problem definition, feasibility study, cost estimation, analysis, design, implementation, testing and maintenance. Hardware and software organization. Several case studies will be considered. PREREQ: CIS 211.

12. Programming Languages
Instruct computer to perform a task
Sometimes called code
Programmer goals
Make language easier for people to understand
Develop languages and development approaches that require people to write fewer instructions to accomplish a task

13. Programming Language Evolution

14. Programming Languages
Summary of capabilities of recent generations
Instruction explosion
Database access
Support for GUIs
Nonprocedural programming
All but 1GL must be translated into CPU instructions prior to execution (compilers and interpreters)

15. Programming Language Characteristics

16. First-Generation Languages
Required programmers to remember binary codes that represented each CPU instruction and to specify all operands as binary numbers
Tedious to program; error-prone

17. Second-Generation Languages
Use mnemonics to represent variables (program instruction memory address) and labels (data item memory address)
Easier to manipulate than binary numbers; assembler translates program into binary CPU instructions
Common in 1950s

18. Third-Generation Languages
Use mnemonics to represent instructions, variables, and labels
Have degree of instruction explosion greater than 1:1
Translated with compilers, link editors, and interpreters
Machine independent
Developed before GUIs, database managers, and Internet

19. Fourth-Generation Languages
Majority were proprietary
many were optional components of database management systems
Most support mixture of procedural and nonprocedural instructions

20. Equivalent Programs in SQL and C

21. Fifth-Generation Languages
Nonprocedural language suitable for developing software that mimics human intelligence
Rule processor accepts a starting state as input and iteratively applies rules to achieve a solution
First appeared in 1960s; not widely used until 1980s

22. Object-Oriented Programming (OOP) Languages
View data and programs as two parts of integrated whole (object)
Promote reusability and portability of source code
Uniquely suited to developing real-time programs
Not clear successors to 5GLs; neither nonprocedural nor exclusively used for developing artificial intelligence

23. OOP Languages
Objects reside in a specific location, wait for messages to arrive, and return a response.

24. Scripting Languages
Enable programmers to develop applications that do most of their work by calling other applications and system software
Enable rapid assembly of application software by “gluing” together capabilities of other programs
Evolved from 4GLs, though most now incorporate OOP concepts

25. Programming Language Standards
Set by ANSI and ISO
Include definitions of:
Language syntax and grammar
Machine behavior for each instruction or statement
Test programs with expected warnings, errors, and execution behavior
Guarantee program portability among operating systems and application programs

26. Compilation
Translates an entire source code file, building a symbol table and object code file as output

27. Program Development

28. Compiler 1. Checks for errors in syntax
2. Issues warnings and/or error messages
3. Builds and uses a Symbol Table as it works
stores information about data items and program components
4. Generates CPU instructions and library calls to carry out the source code instructions
5. Creates an object code file as output

29. Source Code Instruction Types
Data declarations
A data declaration creates an entry in the symbol table
Data operations
A data operation becomes a series of data transformation instructions
Control structures
A control structure becomes a series of control flow instructions
Subprogram calls

30. Data Declarations Define name and data type of program variables
Stored in memory allocated by compiler

31. Symbol Table
The compiler updates a symbol table to keep track of data names, types, and assigned memory addresses.

32. Data Operations Instructions that update or compute a data value
Translated by compiler into equivalent sequence of data movement and data transformation instructions for target CPU
Compiler refers to entries in symbol table to determine source and destination memory addresses for data movement instructions

33. Control Structures
Source code instructions that control the execution of other source code instructions
Common thread is transfer of control among CPU instructions

34. Function Calls
Named instruction sequences executed by call instructions
Transfer control to the instruction following the call by executing a return instruction

35. Implementing Call and Return Instructions
Compiler generates CPU instructions to:
Pass input parameters to the function
Save the value of the IP as a Return Address
Load the IP with the address of the subprogram
Transfer control to the function
Execute CPU instructions within the function
Pass output parameters back to the caller
Load the IP with the saved Return Address
Transfer control back to the caller

36. Symbol Table

37. Compilation Just The First Step
source code
translated by compiler into
object code
linked with library routines to make
load module
loaded into memory by operating system as
runnable machine instructions

38. Link Editing
Statically links external reference calls in object code to library functions; combines them into a single file containing executable code
Can dynamically link external calls by statically linking them to an OS service function that loads and executes dynamic-link library (DLL) functions at run time
Always used by interpreters

39. Key Benefits of Link Editors in Program Translation
A single executable program can be constructed from multiple object code files compiled at different times
A single compiler can generate executable programs that run under multiple operating systems

40. Linking Separately Compiled Functions into a Single Program

41. Dynamic and Static Linking
Library and other subroutines cannot be changed once inserted into executable code
Dynamic linking
Performed during program loading or execution

42. Advantages of Dynamic and Static Linking
Smaller application program executable files
Flexibility
Static
Execution speed
Improves reliability and predictability of executable programs

43. Interpreters
Interleave source code translation, link editing, and execution, one source code instruction at a time
Advantage (vs. compilation)
Provide flexibility to incorporate new or updated code into an application program (dynamic linking)
Disadvantage (vs. compilation)
Increase memory and CPU requirements during program execution

44. Memory and CPU Resources Used During Program Execution

45. Java
Object-oriented programming language and program execution environment
Maximizes reliability of applications and reusability of existing code
Has a standardized target machine language for Java interpreters and compilers
Drawback: Reduced execution speed due to use of interpreted byte codes and OS translation

47. Java How Java
and the JVM relate
to the CPU
and the OS

48. Features of Java
Provision of compilers and virtual machines at little or no cost
Incorporation of JVMs into Web browsers
Increasing development of application software that uses a Web browser as primary I/O device
Ability of Java programs to execute on any combination of computer hardware and OS

49. Symbolic Debugging
Use of an automated tool for testing executable programs; able to:
Trace calls to specific source code statements or subroutines
Trace changes to variable contents
Execute source code instructions one at a time
Detect and report run-time errors to programmer

50. Symbolic Debugger
Uses symbol table, memory map, and source code files to trace memory addresses to specific source code statements and variables
Inserts debugging checkpoints after each source code instruction; program execution can be paused
Debugging vs. production/distribution version
Incorporated directly in most interpreters

51. Application Development Tools

52. Integrated Application Development Tools
Programmer’s workbenches
CASE tools
Integrated set of automated support tools to speed development and testing
Key feature: Level of integration among tools
Require 2-3 times CPU power, memory, and disk storage of typical workstation
Support UP requirements and design disciplines
Key feature: Support for broad range of system development activities with emphasis on model development

53. Programmer’s Workbench Components
Smart program editor
Compiler and/or interpreter
Link editor and large library of classes or subroutines
Interactive tool for prototyping and designing user interfaces
Symbolic debugger
Integrated window-oriented GUI

54. CASE Tools Front-end CASE tools
Support development of requirements and design models
Back-end CASE tools
Generate program source code from models

55. Summary Software development process Programming languages
Compilation and link editing
Interpretation
Symbolic debugging
Application development tools

56. Chapter Goals
Describe the application development process and the role of methodologies, models, and tools
Compare and contrast programming language generations
Explain the function and operation of program translation software, including assemblers, compilers, and interpreters
Describe link editing, and contrast static and dynamic linking
Describe integrated application development software, including programmer’s workbenches and CASE tools