Added some simple symbol handling to the Parser.

This commit is contained in:
2022-05-06 18:55:22 +00:00
parent fc47bf2143
commit fbef044905
5 changed files with 90 additions and 57 deletions
+3 -5
View File
@@ -1,12 +1,10 @@
#ifndef PARSER_H
#define PARSER_H
#include <stdio.h>
#include <stdlib.h>
#include "list.h"
typedef struct {
char* name;
int address;
} Symbol;
#include "token.h"
void ParseTokens(List*);
+1
View File
@@ -1,5 +1,6 @@
.org 0x100
.db msg "Hello, world!", 0
.db more_stuff "And yet another string!", 0
copy r1, msg
copy r2, 0
+8 -8
View File
@@ -7,8 +7,6 @@
#include "../includes/futil.h"
#include "../includes/scanner.h"
List* get_strings(const char*);
int main(int argc, char* args[]) {
if (argc == 1) {
printf("Usage: assm <file1.asm>\n");
@@ -22,13 +20,15 @@ int main(int argc, char* args[]) {
List* list = GenerateTokenList(source_code);
for(int i = 0; i < list->size; i++) {
Token* t = (Token*) list->content[i];
// for(int i = 0; i < list->size; i++) {
// Token* t = (Token*) list->content[i];
printf("[%i] '%s'", t->type, t->lexeme);
if (t->type == NUMBER || t->type == HEX) printf(" NUM: %ld", *((long *) t->value));
printf("\n");
}
// printf("[%i] '%s'", t->type, t->lexeme);
// if (t->type == LABEL) printf("*");
// printf("\n");
// }
ParseTokens(list);
free(source_code);
}
+73 -39
View File
@@ -1,55 +1,89 @@
#include "../includes/parser.h"
#include "../includes/token.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//static List* SymbolsTable;
//static unsigned int program_counter = 0;
void ProcessDirective(List*);
void ProcessVariableDeclaration(List*);
typedef struct {
Token* token;
int address;
} Symbol;
Symbol* CreateSymbol(Token*, int);
void AddSymbol(Token*);
void PrintSymbols(void);
Token* GetSymbol(char*);
List* SymbolsTable;
unsigned int ProgramCounter = 0;
void ParseTokens(List* tokens) {
// for(int i = 0; i < tokens->size; i++) {
// if (((Token *) tokens->content[i])->type == TK_Directive){
// ProcessDirective(tokens);
// }
// }
}
SymbolsTable = CreateList();
void ProcessDirective(List* tokens) {
if (tokens->size < 2) {
printf("Directives failed\n");
return;
}
for(int i = 0; i < tokens->size; i++){
Token* t = tokens->content[i];
Token* directive = (Token *) tokens->content[0];
if (strcmp(".org", directive->value) == 0) {
Token* address_start = (Token*) tokens->content[1];
if (address_start->type == NUMBER) {
long address = strtol(address_start->value, NULL, 10);
printf("Address starting at '%ld'\n", address);
}
else if (address_start->type == HEX) {
long address = strtol(address_start->value, NULL, 16);
printf("Setting address to '%ld'\n", address);
switch(t->type) {
case IDENTIFIER:
case LABEL:
AddSymbol(t);
break;
case STRING:
ProgramCounter += strlen(t->lexeme);
break;
case NUMBER:
case HEX:
if ((long) t->value < 256) ProgramCounter += 1;
else ProgramCounter += 2;
break;
default:
if (t->type > ORG) ProgramCounter += 1;
break;
}
}
if (strcmp(".db", directive->value) == 0) {
ProcessVariableDeclaration(tokens);
}
PrintSymbols();
DestroyList(SymbolsTable);
printf("Program Counter: %d\n", ProgramCounter);
}
void ProcessVariableDeclaration(List* tokens) {
if (tokens->size < 3) {
printf("Invalid variable delcaration\n");
return;
void PrintSymbols(void) {
printf("-----SYMBOLS-----\n");
for(int i = 0; i < SymbolsTable->size; i++) {
Symbol* symbol = SymbolsTable->content[i];
printf("[%#08X] %s\n", symbol->address, symbol->token->lexeme);
}
Token* symbol_token = (Token*) tokens->content[1];
Token* string_literal = (Token*) tokens->content[2];
printf("-----SYMBOLS-----\n");
}
printf("Found string literal.\n");
printf("Name '%s' value: '%s'\n", symbol_token->lexeme, string_literal->lexeme);
void AddSymbol(Token* token) {
if (!token) return;
if (token->type != IDENTIFIER && token->type != LABEL) return;
for(int i = 0; i < SymbolsTable->size; i++) {
Symbol* s = SymbolsTable->content[i];
if (strcmp(s->token->lexeme, token->lexeme) == 0) return;
}
Symbol* symbol = CreateSymbol(token, ProgramCounter);
AddListItem(symbol, sizeof(Symbol), SymbolsTable);
}
Token* GetSymbol(char* name) {
if (!name) return NULL;
return NULL;
}
Symbol* CreateSymbol(Token* token, int offset) {
Symbol* symbol = calloc(1, sizeof(Symbol));
if (!symbol) {
return NULL;
}
symbol->token = token;
symbol->address = offset;
return symbol;
}
+5 -5
View File
@@ -149,7 +149,6 @@ Token* ParseDirective(void) {
free(directive);
//Ignore the line
IgnoreLine();
return NULL;
@@ -164,9 +163,7 @@ Token* ParseString(void) {
int start = Position;
while(!ScannerAtEnd() && PeekScanner() != '"') {
AdvanceScanner();
}
while(!ScannerAtEnd() && PeekScanner() != '"') AdvanceScanner();
int length = Position - start;
@@ -211,7 +208,10 @@ Token* ParseIdentifier(void) {
if (IsOpcode(lexeme, &type)) return CreateToken(lexeme, lexeme, Line, type);
if (IsRegister(lexeme, &type)) return CreateToken(lexeme, lexeme, Line, type);
if (lexeme[length - 1] == ':') return CreateToken(lexeme, lexeme, Line, LABEL);
if (lexeme[length - 1] == ':') {
lexeme[length - 1] = '\0'; //Bit hacky, but this makes the parser's job a bit easier.
return CreateToken(lexeme, lexeme, Line, LABEL);
}
return CreateToken(lexeme, lexeme, Line, IDENTIFIER);
}