1. Chapter 1 Introduction

2. Chapter 1 - Introduction 2 The Goal of Chapter 1 Introduce different forms of language translators Give a high level overview of the structure of a typical compiler Discuss trends in programming languages and machine architecture that are shaping compilers.

3. Chapter 1 - Introduction 3 What is a Compiler? Def: Compiler -- –a program that translates a program written in a language like Pascal, C, PL/I, FORTRAN, or COBOL into another language. An important role of the compiler is to report any errors that it detects.

4. Chapter 1 - Introduction 4 What is an Interpreter? Def: Interpreter -- –Instead of producing a target program at translation, it appears to directly execute the operations specified in the source program on the inputs specified by the user.

5. Chapter 1 - Introduction 5 What are the Differences? Compiler is usually much faster. Interpreter usually gives better diagnostics.

6. Chapter 1 - Introduction 6 2. Structure of a Compiler So far we have viewed the compiler as a single black box.

7. Chapter 1 - Introduction 7 2. Structure of a Compiler Now we want to open that box.

8. Chapter 1 - Introduction 8

9. 9 2. Structure of a Compiler 1. The Lexical Analyzer reads the stream of characters and groups them into meaningful sequences called lexemes. 2. The Syntax Analyzer depicts the grammatical structure of the lexemes in a syntax tree 3. The Semantic Analyzer checks the tree for semantic consistency (type checking)

10. Chapter 1 - Introduction 10 2. Structure of a Compiler 4. Intermediate Code Generation – produces assembly like instructions (three address code) 5. Code Optimization – seeks to improve intermediate code so better target code can be generated 6. Code Generation – takes the intermediate code and maps to the target code.

11. Chapter 1 - Introduction 11 2. Structure of a Compiler 7. Symbol Table Management - An essential function of the compiler is to record the variable names used in the source program and collect attributes of each name. (type, scope,…)

12. Chapter 1 - Introduction 12 2.8 The Grouping of the Phases into Passes Pass – several phases may be grouped together into a pass that reads an input file and writes an output file. –Front End Lexical Analysis, Syntax Analysis, Semantic Analysis, and Intermediate Code Generation –Code Optimization Might be an optional pass. –Back End Code Generation for a specific target machine.

13. Chapter 1 - Introduction 13 2.9 Compiler-Construction Tools The compiler writer, like any software developer, can profitably use modern software development environments containing tools –Editor, debugger, version managers, profilers, test harnesses, … There are also tools to help implement various phases of a compiler. –Scanner Generator, Parser generator, …

14. Chapter 1 - Introduction 14

15. Chapter 1 - Introduction 15 3. The Evolution of Programming Languages

16. Chapter 1 - Introduction 16 3.1 The Move to Higher-Level Languages

17. Chapter 1 - Introduction 17 3.2 Impacts on Compilers

18. Chapter 1 - Introduction 18 4. The Science of Building a Compiler

19. Chapter 1 - Introduction 19 4.1 Modeling in Compiler Design and Implementation

20. Chapter 1 - Introduction 20 4.2 The Science of Code Optimization

21. Chapter 1 - Introduction 21 5. Applications of Compiler Technology

22. Chapter 1 - Introduction 22 5.1 Implementation of High Level Programming Languages

23. Chapter 1 - Introduction 23 5.2 Optimizations for Computer Architectures

24. Chapter 1 - Introduction 24 5.3 Design of New Computer Architectures

25. Chapter 1 - Introduction 25 5.4 Program Translations

26. Chapter 1 - Introduction 26 5.5 Software Productivity Tools

27. Chapter 1 - Introduction 27 6. Programming Language Basics

28. Chapter 1 - Introduction 28 6.1 The Static/Dynamic Distinction

29. Chapter 1 - Introduction 29 6.2 Environments and States

30. Chapter 1 - Introduction 30 6.3 Static Scope andBlock Structure

31. Chapter 1 - Introduction 31 6.4 Explicit Access Control

32. Chapter 1 - Introduction 32 6.5 Dynamic Scope

33. Chapter 1 - Introduction 33 6.6 Parameter Passing Mechanisms

34. Chapter 1 - Introduction 34 6.7 Aliasing

35. Chapter 1 - Introduction 35 7. Summary