117 lines
3.7 KiB
C
117 lines
3.7 KiB
C
//Defining a symbol table
|
|
//Using a Linked List Structure. Head of linked List points to parent scope (if one exists)
|
|
//Tail of Linked List points to a Linked List of all the child scopes
|
|
//T
|
|
//*#include "symbol_table.h"
|
|
/*
|
|
#include <stdbool.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
|
|
typedef struct ListOfTable{
|
|
struct SymbolTable* table;
|
|
//struct ListOfTable* prev;
|
|
struct ListOfTable* next;
|
|
|
|
}ListOfTable;
|
|
|
|
typedef union Value{
|
|
int* value_of_int;
|
|
void* value_of_pointer;
|
|
bool* value_of_bool;
|
|
char* value_of_char;
|
|
}Value;
|
|
|
|
typedef struct TableNode{
|
|
char* theType;
|
|
char* theName;
|
|
Value* value;
|
|
struct TableNode* next;
|
|
//this next value is an int for string types to tell you how far to traverse a buffer for the string
|
|
int StrLength;
|
|
}TableNode;
|
|
|
|
typedef struct SymbolTable{
|
|
TableNode* entries;
|
|
struct SymbolTable* Parent_Scope;
|
|
struct ListOfTable* Children_Scope;
|
|
int Line_Number;
|
|
int Column_Number;
|
|
}SymbolTable;
|
|
|
|
*/
|
|
|
|
SymbolTable* CreateScope(SymbolTable* ParentScope, int Line, int Column){
|
|
SymbolTable* table = (SymbolTable*)malloc(sizeof(SymbolTable));
|
|
table->Line_Number = Line;
|
|
table->Column_Number = Column;
|
|
table->Parent_Scope = ParentScope;
|
|
table->Children_Scope = NULL;
|
|
table->entries = NULL;
|
|
if(ParentScope != NULL){
|
|
if(ParentScope->Children_Scope == NULL){
|
|
ListOfTable* newEntry = (ListOfTable*)malloc(sizeof(ListOfTable));
|
|
newEntry->next = NULL;
|
|
//newEntry->prev = NULL;
|
|
newEntry->table = table;
|
|
ParentScope->Children_Scope = newEntry;
|
|
} else{
|
|
ListOfTable* newEntry = (ListOfTable*)malloc(sizeof(ListOfTable));
|
|
//newEntry->prev = NULL;
|
|
newEntry->table= table;
|
|
ListOfTable* oldEntry = ParentScope->Children_Scope;
|
|
ParentScope->Children_Scope = newEntry;
|
|
newEntry->next = oldEntry;
|
|
}
|
|
}
|
|
return table;
|
|
}
|
|
|
|
|
|
TableNode* CreateEntry(SymbolTable* table, char* typeOf, char* id){
|
|
TableNode* newEntry = (TableNode*)malloc(sizeof(TableNode));
|
|
newEntry->theType = typeOf;
|
|
newEntry->theName = id;
|
|
if(table->entries == NULL){
|
|
table->entries = newEntry;
|
|
return newEntry;
|
|
} else{
|
|
TableNode* oldEntry = table->entries;
|
|
table->entries = newEntry;
|
|
newEntry->next = oldEntry;
|
|
return newEntry;
|
|
}
|
|
}
|
|
TableNode * table_lookup(SymbolTable * table, char * x){
|
|
TableNode * entrie = table->entries;
|
|
for(; entrie != NULL; entrie = entrie->next){
|
|
if (!strcmp(entrie->theName, x)){
|
|
return entrie;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
TableNode * look_up(SymbolTable * table, char * x){
|
|
if(table == NULL){
|
|
return NULL;
|
|
}
|
|
TableNode * ret = table_lookup(table, x);
|
|
if (ret != NULL){
|
|
return ret;
|
|
}
|
|
return look_up(table->Parent_Scope, x);
|
|
}
|
|
|
|
//uncomment the below main function along with the headers above for a simple standalone test of table and entry creation
|
|
/*
|
|
int main(){
|
|
char* String = "STRING";
|
|
char* X = "X";
|
|
SymbolTable* Second = CreateScope(NULL, 2,2);
|
|
printf("Line number is %d, Column number of scope is %d\n",Second->Line_Number,Second->Column_Number);
|
|
TableNode* First_Entry = CreateEntry(Second,String,X);
|
|
printf("The value of the first entry is %s\n",First_Entry->theType);
|
|
return 0;
|
|
}
|
|
*/
|