Chapter 1 - Intro to Compiling

Chapter 1 - Introduction to Compiling

Reading: pp.1 - 24

Defn: compiler - is a translator that translates a source language into a target language.

P#1: Give an example of a compiler and the associated source and target languages.

At the highest level, we can think of compilation consisting of two parts:

analysis - break up the source code into intermediate pieces
synthesis - generates the target code

A compiler can consist of several passes and several different phases. For the project in this class, our compiler will proceed as follows:

source program
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      V
lexical analyzer
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syntactic analyzer
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      V
semantic analyzer
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intermediate code generator
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code generator
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      V
target program

We will discuss some simple code optimization although it is beyond the scope of this course to get into sophistocated code optimization. The source program in this course will be a subset of C and the target program will be for the Interpreter discussed in class.

Our compiler will need auxiliary data structures and functions to handle symbol table and error handling information.

Consider the translation process as it is applied to the following C statement:

taxes = salary * 0.30 + 500;

This translates as follows:

taxes = salary * 0.30  + 500;
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  lexical analyzer
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id1 = id2 * 0.30 + 500;
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  syntactic analyzer
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    =
id1              +
          *        500
      id2   0.30
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 semantic analyzer
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     =
id1              +
          *        (float) 500
      id2   0.30
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intermediate code generator
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mov temp1,0.30
mov ax,id2
mul temp1
add ax,(float)500
mov id1,ax
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     MASM 6.11
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         V
target program (.EXE)

P#2: Explain as best you can all of the things the compiler has to do with the following C program.

#include <stdio.h>
#if SYS == RH5.1
  #define LIB  "rh51.h"
#elif SYS == RH6.0
  #define LIB "rh60.h"
#else
  #define LIB "rh62.h"
#endif
#include LIB

#define MAX(x,y) ((x) > (y) ? (x) : (y))

main ()
{
  int i = 3, j =  7;
  printf ("%d",MAX(i,j));
}