symtab.c

#include <stdio.h>
#include <string.h>
#include "symtab.h"

//Constants used to control hash table
#define SHIFT 4

//	hash function
static int hash (char * key){
	int temp = 0;
	int i = 0;
	while (key[i] != '\0'){
		temp = ((temp << SHIFT) + key[i]) % SIZE;
		++i;
	}
	return temp;
}	
	
//	The hash table
static HashTableList hashTableList = NULL;
static HashTableList curHashTable = NULL;

//	Hash table List initialiization
void initSymbolTable(void){
	hashTableList = (HashTableList)malloc(sizeof(struct HashTableRec));
	hashTableList->inner = NULL;
	hashTableList->outer = NULL;
	hashTableList->scope = 0;
	hashTableList->location = 0;
	hashTableList->visited = 0;
	curHashTable = hashTableList;
}

//	Come into new scope
void intoNewScope(void){
	HashTableList temp = (HashTableList)malloc(sizeof(struct HashTableRec));
	temp->outer = curHashTable;
	temp->inner = curHashTable->inner;
	if (temp->inner)
		temp->inner->outer = temp;
	curHashTable->inner = temp;	

	temp->scope = curHashTable->scope + 1;
	temp->location = 0;
	temp->visited = 0;
	
	if (hashTableList == curHashTable)
		hashTableList = temp;
	curHashTable = temp;
}

//      Go out the scope
void closeScope(void){
	curHashTable = curHashTable->outer;
}

//      Go into inner scope. Used in phase 2(checking)
void inScope(void){
	HashTableList temp = curHashTable->inner;

	while (temp->inner){	
		if (temp->inner->scope > curHashTable->scope)
        		temp = temp->inner;
		else break;
	}
	while (temp != curHashTable){
		if ((temp->scope == curHashTable->scope + 1) && (temp->visited == 0))
			break;
		temp = temp->outer;
	}

	curHashTable = temp;
	curHashTable->visited = 1;
}

void outScope(void){
	HashTableList temp = curHashTable->outer;
	while (temp->scope >= curHashTable->scope){
		temp = temp->outer;
	}
	curHashTable = temp;
}

void insertAllPrmt(BucketList prmtList){
	while (prmtList){
		int h = hash(prmtList->name);
		BucketList l = curHashTable->hashTable[h];
		BucketList temp = prmtList;

		temp->loc = curHashTable->location++;	
		if ( l ){
                        while ( l->next ) l = l->next;
                        l->next = temp;
                }
		else
			curHashTable->hashTable[h] = temp;
		prmtList = prmtList->next;
		temp->next = NULL;
	}
}

//	Insertion to hash table
void st_insert(char * name, int lineno, NodeKind kind, int subKind, int arrSize, TokenType type, BucketList found){
	if (found == NULL){
		int h = hash(name);
		BucketList l = curHashTable->hashTable[h];

		BucketList temp = (BucketList)malloc(sizeof(struct BucketListRec));	
		temp->name = name;
		temp->loc = curHashTable->location++;
		temp->kind = kind;
		temp->subKind = subKind;
		temp->arrSize = arrSize;
		temp->type = type;
		temp->next = NULL;

		temp->lines = (LineList)malloc(sizeof(struct LineListRec));
                temp->lines->lineno = lineno;
		temp->lines->next = NULL;

		if ( l ){
                        while ( l->next ) l = l->next;
			l->next = temp;
                }
		else
			curHashTable->hashTable[h] = temp;
	}
	else{
		LineList t = found->lines;
		while (t->next != NULL) t = t->next;
		t->next = (LineList)malloc(sizeof(struct LineListRec));
		t->next->lineno = lineno;
		t->next->next = NULL;
	}
}

BucketList st_lookup(char * name, int lookupMode){
	int nextScope = curHashTable->scope;
	HashTableList tableSearched = curHashTable;

	int h = hash(name);
	BucketList l;

	if (lookupMode == 0){
		while (nextScope >= 0){
			while (tableSearched->scope != nextScope) tableSearched = tableSearched->outer;
			nextScope--;

			l = tableSearched->hashTable[h];
			while((l != NULL) && (strcmp(name, l->name) != 0))
				l = l->next;
			if ( l )
				return l;
		}
	}
	else{
		l = tableSearched->hashTable[h];
                while((l != NULL) && (strcmp(name, l->name) != 0))
                        l = l->next;
                if ( l )
                        return l;
	}

	return NULL;
}

void printSymTab(FILE *listing){
	HashTableList cur = hashTableList;
	int i;
	BucketList l;

	while (cur){
		fprintf(listing, "\nName          Scope  Loc  V/P/F  Array?  ArrSize  Type  Line Numbers\n");
        	fprintf(listing, "-----------------------------------------------------------------------\n");
		for (i = 0; i < SIZE; i++){
			BucketList l = cur->hashTable[i];
			while ( l ){
				fprintf(listing, "%-14s", l->name);
				fprintf(listing, "%-7d", cur->scope);
				fprintf(listing, "%-5d", l->loc);
				if (l->kind == PrmtK){
					fprintf(listing, "%-7s", "Par");
				}
				else{
					if (l->subKind == FuncK)
						fprintf(listing, "%-7s", "Func");
					else
						fprintf(listing, "%-7s", "Var");
				}
				if (l->subKind == 2){
					fprintf(listing, "%-8s", "Array");	
					fprintf(listing, "%-9d", l->arrSize);
					fprintf(listing, "%-6s", "array");
				}
				else{
					fprintf(listing, "%-8s", "No");
					fprintf(listing, "%-9s", "-");
					if (l->type == VOID)
						fprintf(listing, "%-6s", "void");
					else
						fprintf(listing, "%-6s", "int");
				}
				LineList t = l->lines;
				while ( t ){
					fprintf(listing, "%-5d", t->lineno);
					t = t->next;
				}
				fprintf(listing, "\n");
				l = l->next;
			}
		}
		cur = cur->outer;
	}
	
	
	
}