Fig 1.5: preprocessor, linker/loader

Phases - Fig 1.6 and 1.7

• Lexer
• Parser
• Semantic analysis
• Int Code gen
• Optimization
• Code Gen

Token vs lexeme

Lexer and parser generators

• Lex, YACC, FLex, Bison, ANTLR, CUP, Coco/R, JavaCC, SableCC
• AFlex, AYACC, Dmitry Kazakov Simple Components, AdaCore Langkit

Transforms: sequence of characters, seq of tokens, abstract parse tree, intermediate code, asm, machine code

• Actually, parser calls lexer

Importance of phases has changed

Cross compiler

Front end, back end, intermediate code

Symbol table: what's in it when it's built

Attributes move up and down tree

• Example: print expression
• Example: evaluate expression

Abstract vs Concrete Parse Tree

Decisions

• Source language: Ada Baby
• Target language/machine
• RISC vs CISC
• x86, SPARC, ARM, MIPS
• Run on: SPARC machine or emulator, RPi, SPIM
• Implementation language: Java or Ada
• Tools or by hand
• Coco/R
• SableCC
• JavaCC
• Ada Tools
• Groups or individual
• Assignment: Try to implement a lexer using Coco or SableCC