/*
* Description: Process the extern definition in first transition.
* Adds it into the symbol table
* Input: 1. Current transition
*/
void first_transition_process_extern(transition_data* transition) {
symbol_node_ptr p_symbol = NULL;
char* extern_name = get_next_word(transition);
/* If we have an extern*/
if (extern_name) {
symbol_node_ptr p_searched_symbol = search_symbol(extern_name);
/* Extern does not exists in symbol table */
if (!p_searched_symbol) {
/* Create new symbol in table or die */
p_symbol = create_symbol(extern_name, NO_ADDRESS, true, true);
if (p_symbol) {
add_symbol_to_list(p_symbol);
/* Make sure that the line does not contain left overs */
if (!is_end_of_data_in_line(transition->current_line_information)) {
print_compiler_error("Invalid tokens after extern definition", transition->current_line_information);
transition->is_compiler_error = true;
return;
}
}
/* Could not allocat memory, die*/
else {
transition->is_runtimer_error = true;
free(extern_name);
return;
}
}
/* Extern is already in table */
else {
print_compiler_error("Each extern can be defined only once", transition->current_line_information);
transition->is_compiler_error = true;
return;
}
}
}
/*
* Description: Processes a line in input file
* Input: 1. Current transition data
* 2. Output files
*/
void second_transition_process_line(transition_data* transition, compiler_output_files* output_files) {
char* type = NULL;
int index;
/* Step 3 - Skips label if exists */
skip_label(transition->current_line_information);
index = transition->current_line_information->current_index;
/* Read line type */
type = get_next_word(transition);
/* Step 4 - Handle line type */
if (type == NULL) {
print_compiler_error("Invalid line", transition->current_line_information);
transition->is_compiler_error = true;
}
/* Line is data initialization - Ignores it */
else if ((strcmp(type, DATA_OPERATION) == 0) || (strcmp(type, STRING_OPERATION) == 0)) {
/* Ignore */
}
/* Step 5 - Line is extern */
else if (strcmp(type, EXTERN_OPERATION) == 0) {
create_extern_output_file_if_needed(output_files, transition->current_line_information->file_name);
if (output_files->extern_file == NULL) {
transition->is_runtimer_error = true;
}
} else if (strcmp(type, ENTRY_OPERATION) == 0) {
/* Process entry */
second_transition_process_entry(transition, output_files);
} else {
/* Process operation */
transition->current_line_information->current_index = index;
second_transition_process_operation(transition, output_files);
}
if (type != NULL) {
free(type);
}
}
/**
* Will attempt to parse the rest of the input line according to the
* restrictions given by the format string. The format string is used to
* specify, in the given order, how to parse the next token. The following
* format is accepted (strictly):
*
* s -> Source register
* d -> Destination register
* l -> Label
* c -> Constant
* n -> Literal number
* t -> Place an empty term after this term
* [ -> Start 'or' expression (non-recursive)
* ] -> End 'or' expression
*
* Note that the or expression works as expected, so "[lcn]" translates to
* "take whichever successfully parses first, either a label, constant, or
* a number".
*
* If the or condition fails, or any parsing fails, an error is printed
* and all processing stops (the function does however return instead of
* calling exit()).
*
* @param prog Contains general program information thus far gathered,
* and is used for handling error reporting.
* @param opcode The binary operation that this line started with.
* @param fmt The format string for what arguments to expect.
* @param misc Any bits that need to be added as the last child to the
* opcode term.
*/
void process_instruction(struct program *prog, char *opcode, const char *fmt,
char *misc){
// create a term for this instruction
struct Term *t = create_term(opcode, strlen(opcode), 0);
if(!t){
#ifdef DEBUG
fprintf(stderr, "whoops! Looks like a nul-pointer...\n");
#endif
prog->error_code = -1;
return;
}
t->trans = 1;
struct Term *child;
prog->term_count++;
t->pos = prog->term_count;
#ifdef DEBUG
fprintf(stderr, "OPCODE: '%s'\n", opcode);
#endif
// add term to our program
if(prog->terms){
prog->end_term->next_term = t;
prog->end_term = t;
}
else{
prog->terms = t;
prog->end_term = t;
}
if(!*opcode)
return;
#ifdef DEBUG
fprintf(stderr, "FMT CODE: '%s'.\n", fmt);
#endif
// opcode argument parsing
short reg = -1;
char *iden = 0;
char *tok = 0;
int c = 0, or = 0, val = -1;
while(fmt[c]){
if(fmt[c] == 't'){
prog->end_term->next_term = create_term(0, 0, 0);
prog->end_term = prog->end_term->next_term;
prog->term_count++;
prog->end_term->pos = prog->term_count;
prog->end_term->absolute_pos = prog->line_count;
}
else if(or && ( (reg != -1) | (iden ? 1 : 0) | (val != -1) )
&&fmt[c] != ']'){
// do nothing...
}
else if(fmt[c] == '['){
or = 1;
}
else if(fmt[c] == ']'){
or = 0;
// if all options failed, report parse error
if(!reg && !iden && !val){
// TODO: create standardized error reporting....
print_compiler_error(prog, RED_C);
print_asterisk(RED_C, stderr);
fprintf(stderr, "\tUnexpected opcode argument.\n");
prog->error_code = GARBAGE;
return;
}
// reset everything
reg = -1;
iden = 0;
tok = 0;
}
else if(fmt[c] == 's'){
reg = read_src_reg(prog, or);
if(!or && reg == -1){
return;
}
}
else if(fmt[c] == 'd'){
reg = read_dst_reg(prog, or);
if(!or && reg == -1){
return;
}
}
else if(fmt[c] == 'l'){
if(!tok && or){
tok = strtok(0, ", \t");
iden = tok;
}
else if(!or){
iden = strtok(0, ", \t");
}
else{
iden = tok;
}
// create the term and add to the end
struct Term *nt = create_term(iden, strlen(iden), 0);
prog->term_count++;
nt->pos = prog->term_count;
prog->end_term->next_term = nt;
prog->end_term = nt;
nt->absolute_pos = prog->line_count;
#ifdef DEBUG
fprintf(stderr, "GOTS A LABEL!\n");
#endif
}
else if(fmt[c] == 'n'){
if(!tok && or){
tok = strtok(0, ", \t");
iden = tok;
}
else if(!or){
iden = strtok(0, ", \t");
}
else{
iden = tok;
}
if(!check_explicit_literal(iden, prog)){
if(!or){
print_expected_literal(iden, prog);
return;
}
iden = 0;
}
else{
val = process_literal(iden, MAX_INT);
iden = 0;
if(val < 0){
print_literal_too_large(iden, prog);
return;
}
else{
#ifdef DEBUG
fprintf(stderr, "GOTS A LITERAL!\n");
#endif
// create the term and add to the end
struct Term *nt = create_term(numtob(val, WORD_SIZE),
strlen(iden), 0);
nt->trans = 1;
prog->term_count++;
nt->pos = prog->term_count;
prog->end_term->next_term = nt;
prog->end_term = nt;
nt->absolute_pos = prog->line_count;
}
}
}
else if(fmt[c] == 'c'){
if(!tok && or){
tok = strtok(0, ", \t");
iden = tok;
}
else if(!or){
iden = strtok(0, ", \t");
}
else{
iden = tok;
}
if(!check_const(iden, prog)){
if(!or){
print_expected_const(iden, prog);
return;
}
iden = 0;
}
else{
#ifdef DEBUG
fprintf(stderr, "GOTS A CONSTANT!\n");
#endif
// create the term and add to the end
struct Term *nt = create_term(iden, strlen(iden), 0);
prog->term_count++;
nt->pos = prog->term_count;
prog->end_term->next_term = nt;
prog->end_term = nt;
nt->absolute_pos = prog->line_count;
}
}
else{
fprintf(stderr, " * Error In Compiler!!!\n\tStrange format code: "
"'%c'.\n", fmt[c]);
}
if(reg != -1){
child = create_single_char_term(dtoc(reg-1), 0);
child->absolute_pos = prog->line_count;
child->trans = 1;
add_child_term(child, t, prog);
if(!or)
reg = -1;
}
c++;
}
// Finally, add miscellaneous bits to the end
if(misc){
struct Term *mt = create_term(misc, strlen(misc), 0);
mt->trans = 1;
mt->absolute_pos = prog->line_count;
add_child_term(mt, t, prog);
}
}