compiler.h

#pragma once

/*
* compiler.h
*/

#define TRUE 1
#define FALSE 0

#define NOOPSTMT    100
#define PRINTSTMT   101
#define ASSIGNSTMT  102
#define IFSTMT      103
#define GOTOSTMT    104

#define KEYWORDS    8
#define RESERVED    28
#define VAR         1
#define IF          2
#define WHILE       3 
#define SWITCH      4
#define CASE        5
#define DEFAULT     6
#define PRINT       7
#define ARRAY       8
#define PLUS        9
#define MINUS       10
#define DIV         11
#define MULT        12
#define EQUAL       13
#define COLON       14
#define COMMA       15
#define SEMICOLON   16
#define LBRAC       17
#define RBRAC       18
#define LPAREN      19
#define RPAREN      20
#define LBRACE      21
#define RBRACE      22
#define NOTEQUAL    23
#define GREATER     24
#define LESS        25
#define ID          26
#define NUM         27
#define ERROR       28

// This implementation does not allow tokens that are more
// than 100 characters long
#define MAX_TOKEN_LENGTH 100

// The following global variables are defined in compiler.c:
extern char token[MAX_TOKEN_LENGTH];
extern int  ttype;

//---------------------------------------------------------
// Data structures:

struct varNode
{
	char* name;
	int   value;
};

struct gotoStatement
{
	struct statementNode * target;
};

struct assignmentStatement
{
	struct varNode * lhs;
	struct varNode * op1;
	struct varNode * op2;
	int op;  // PLUS, MINUS, MULT, DIV => lhs = op1 op op2;
	// 0 => lhs = op1;
};

struct printStatement
{
	struct varNode * id;
};

struct ifStatement
{
	struct varNode * op1;
	struct varNode * op2;
	int relop;   // GREATER, LESS, NOTEQUAL
	struct statementNode * true_branch;
	struct statementNode * false_branch;
};

struct statementNode
{
	int stmt_type;     // NOOPSTMT, PRINTSTMT, ASSIGNSTMT, IFSTMT, GOTOSTMT
	struct assignmentStatement * assign_stmt;  // NOT NULL iff stmt_type == ASSIGNSTMT
	struct printStatement      * print_stmt;   // NOT NULL iff stmt_type == PRINTSTMT
	struct ifStatement         * if_stmt;      // NOT NULL iff stmt_type == IFSTMT
	struct gotoStatement       * goto_stmt;    // NOT NULL iff stmt_type == GOTOSTMT
	struct statementNode       * next;         // next statement in the list or NULL 
};

//---------------------------------------------------------
// Functions that are provided:

void print_debug(const char * format, ...);
void ungetToken();
int  getToken();

/*
* You need to write a function with the signature that follows this comment.
* It is supposed to parse the input program and generate an intermediate
* representation for it. Write all your code in a separate file and include
* this header file (compiler.h) in your code.
*
* A) If you write your code in C, compile using the following command:
*
*   $ gcc compiler.c yourcode.c
*
* and include the header in your C code like this:
*
*  #include "compiler.h"
*
* B) If you use C++, use the following commands to compile your code:
*
*   $ gcc -c compiler.c
*   $ g++ yourcode.cpp compiler.o
*
* and also make sure that you include this header file in the following way in
* your C++ code:
*
*  extern "C" {
*      #include "compiler.h"
*  }
*
*/

struct statementNode * parse_program_and_generate_intermediate_representation();