void stmt_codegen(struct stmt *s, FILE *f) {
if(!s) return;
switch(s -> kind) {
case STMT_DECL:
decl_codegen(s -> decl, f, SYMBOL_LOCAL);
break;
case STMT_EXPR:
expr_codegen(s -> expr, f);
register_free(s -> expr -> reg);
break;
case STMT_IF_ELSE: {
int done = assembly_jump_label++;
expr_codegen(s -> expr, f);
fprintf(f, "\tCMP $0, %s\n", register_name(s -> expr -> reg));
register_free(s -> expr -> reg);
if(s -> else_body) {
int el = assembly_jump_label++;
// jump to else
fprintf(f, "\tJE L%d\n", el);
stmt_codegen(s -> body, f);
assembly_comment(f, "\t# jump to done label (don't evaluate else label)\n");
fprintf(f, "JMP L%d\n", done);
assembly_comment(f, "\t# else label\n");
fprintf(f, "L%d:\n", el);
stmt_codegen(s -> else_body, f);
assembly_comment(f, "\t# done label\n");
fprintf(f, "L%d:\n", done);
}
else {
// jump to done
fprintf(f, "\tJE L%d\n", done);
stmt_codegen(s -> body, f);
assembly_comment(f, "\t# done label\n");
fprintf(f, "L%d:\n", done);
}
break;
}
case STMT_FOR: {
// check for nulls since all exprs optional
int loop = assembly_jump_label++;
int done = assembly_jump_label++;
if(s -> init_expr) {
expr_codegen(s -> init_expr, f);
register_free(s -> init_expr -> reg);
}
// loop label
assembly_comment(f, "\t# loop label\n");
fprintf(f, "L%d:\n", loop);
if(s -> expr) {
expr_codegen(s -> expr, f);
// don't need the return value
fprintf(f, "\tCMP $0, %s\n", register_name(s -> expr -> reg));
register_free(s -> expr -> reg);
assembly_comment(f, "\t# jump to done label (break condition)\n");
fprintf(f, "\tJE L%d\n", done);
}
stmt_codegen(s -> body, f);
if(s -> next_expr) {
expr_codegen(s -> next_expr, f);
register_free(s -> next_expr -> reg);
}
assembly_comment(f, "\t# unconditional jump to next loop\n");
fprintf(f, "JMP L%d\n", loop);
assembly_comment(f, "\t# done label\n");
fprintf(f, "L%d:\n", done);
break;
}
case STMT_WHILE:
fprintf(stderr, "CODEGEN_ERROR: cminor does not support while loops\n");
exit(1);
break;
case STMT_PRINT: {
struct expr *curr = s -> expr;
while(curr) {
expr_codegen(curr, f);
int count = 0;
if(ASSEMBLY_COMMENT_FLAG) {
fprintf(f, "\t# move arg %d (in %s) into %s\n", count, register_name(curr -> reg), register_arg_names[count]);
}
fprintf(f, "\tMOVQ %s, %s\n", register_name(curr -> reg), register_arg_names[count++]);
register_free(curr -> reg);
// calls func_codegen which save ret val in reg
// so need to free reg beforehand
stmt_call_print(curr, f);
curr = curr -> next;
}
break;
}
case STMT_RET:
expr_codegen(s -> expr, f);
if(ASSEMBLY_COMMENT_FLAG) {
fprintf(f, "\n\t# return statement (return ");
expr_fprint(f, s -> expr);
fprintf(f, ")\n");
}
if(s -> expr) {
fprintf(f, "\tMOVQ %s, %%rax\n", register_name(s -> expr -> reg));
register_free(s -> expr -> reg);
}
// postamble
assembly_comment(f, "\t### function postamble\n");
assembly_comment(f, "\t# restore callee-saved registers\n");
fprintf(f, "\tPOPQ %%r15\n");
fprintf(f, "\tPOPQ %%r14\n");
fprintf(f, "\tPOPQ %%r13\n");
fprintf(f, "\tPOPQ %%r12\n");
fprintf(f, "\tPOPQ %%rbx\n");
assembly_comment(f, "\t# reset stack to base pointer\n");
fprintf(f, "\tMOVQ %%rbp, %%rsp\n");
assembly_comment(f, "\t# restore the old base pointer\n");
fprintf(f, "\tPOPQ %%rbp\n");
fprintf(f, "\tRET\n");
break;
case STMT_BLOCK:
stmt_codegen(s -> body, f);
break;
}
stmt_codegen(s -> next, f);
}
void decl_codegen(struct decl *d, FILE * file){
if(!d)return;
if(d->symbol->kind == SYMBOL_GLOBAL){
if(!d->code && !d->value && d->type->kind != TYPE_FUNCTION){
if(d->type->kind != TYPE_STRING)fprintf(file,".data\n%s: .quad 0\n",d->name);
else{
//printf("teste");
fprintf(file,".data\n.global %s\n%s:\n .string \"\" \n",d->name,d->name);
}
}
else{
if(d->value && d->type->kind != TYPE_FUNCTION){
if(d->type->kind == TYPE_STRING && d->type->kind != TYPE_FUNCTION){
fprintf(file,".data\n.global %s\n%s:\n .string ""%s""\n",d->name,d->name,d->value->string_literal);//nao esquecer de tratar quebras de linha
}
else if(d->type->kind != TYPE_FUNCTION) fprintf(file,".data\n.global %s\n%s:\n .quad %d\n",d->name,d->name,d->value->literal_value);//pode ter expressoes do tipo 10+1 na declaracao?
}else{
if(d->code){
fprintf(file,".text\n.global %s\n%s:\n",d->name,d->name);
struct param_list *p = d->type->params;
fprintf(file," pushq %%rbp\n movq %%rsp, %%rbp\n");
int parameters_cont = 0;
while(p){
p = p->next;
parameters_cont++;
}
if(parameters_cont >= 1){
fprintf(file," pushq %%rdi\n");
}
if(parameters_cont >= 2){
fprintf(file," pushq %%rsi\n");
}
if(parameters_cont >= 3){
fprintf(file," pushq %%rdx\n");
}
if(parameters_cont >= 4){
fprintf(file," pushq %%rcx\n");
}
if(parameters_cont >= 5){
fprintf(file," pushq %%r8\n");
}
if(parameters_cont == 6){
fprintf(file," pushq %%r9\n");
}
if(d->symbol->total_locals > 0){
fprintf(file," subq $%d,%%rsp\n",d->symbol->total_locals*8);
}
fprintf(file," pushq %%rbx\n");
fprintf(file," pushq %%r12\n");
fprintf(file," pushq %%r13\n");
fprintf(file," pushq %%r14\n");
fprintf(file," pushq %%r15\n\n");
stmt_codegen(d->code,file);
fprintf(file,"FUNCAO%d:\n",funcoes);
fprintf(file,"\n");
fprintf(file," popq %%r15\n");
fprintf(file," popq %%r14\n");
fprintf(file," popq %%r13\n");
fprintf(file," popq %%r12\n");
fprintf(file," popq %%rbx\n");
fprintf(file," movq %%rbp,%%rsp\n");
fprintf(file," popq %%rbp\n");
fprintf(file," ret\n");
funcoes++;
//postamble como tratar
}
}
}
}
else if(d->symbol->kind == SYMBOL_LOCAL){
if(d->value){
expr_codegen(d->value,file);
fprintf(file," movq %s,-%d(%%rbp)\n",register_name(d->value->reg),d->symbol->param_local_variables*8);//arrumar isso, voce usou valor aleatorio,
register_free(d->value->reg);
//dont forget to free registers
//voltar no video do dia 20, minuto 35 para tratar o caso das strings
}
}
decl_codegen(d->next,file);
}
void stmt_codegen(struct stmt *s, FILE * output) {
struct expr * e_cursor;
int label_save;
if (!s) return;
switch (s->kind) {
case STMT_DECL:
decl_codegen(s->decl, output);
break;
case STMT_EXPR:
expr_codegen(s->expr, output);
register_free(s->expr->reg);
break;
case STMT_IF_ELSE:
fprintf(output, "\n\t## if statement ##\n");
label_save = label_count;
label_count+=2;
expr_codegen(s->expr, output);
fprintf(output, "\tCMP $0, %s\n", register_name(s->expr->reg));
register_free(s->expr->reg);
fprintf(output, "\tJE .L%d\n", label_save);
stmt_codegen(s->body, output);
fprintf(output, "\tJMP .L%d\n", label_save+1);
fprintf(output, "\t.L%d:\n", label_save);
stmt_codegen(s->else_body, output);
fprintf(output, "\t.L%d:\n", label_save+1);
fprintf(output, "\n\t## end of if statement ##\n");
break;
case STMT_FOR:
label_save = label_count;
label_count+=2;
fprintf(output, "\n\t## for loop ##\n");
expr_codegen(s->init_expr, output);
if(s->init_expr) { // for infinite for loops
register_free(s->init_expr->reg);
}
fprintf(output, "\t.L%d:\n", label_save);
expr_codegen(s->expr, output);
if (s->expr) { // for infinite for loops
register_free(s->expr->reg);
fprintf(output, "\tCMP $0, %s\n", register_name(s->expr->reg));
fprintf(output, "\tJE .L%d\n", label_save+1);
}
stmt_codegen(s->body, output);
expr_codegen(s->next_expr, output);
if (s->next_expr) {
register_free(s->next_expr->reg);
}
fprintf(output, "\tJMP .L%d\n", label_save);
fprintf(output, "\t.L%d:\n", label_save+1);
fprintf(output, "\t## end of for loop ##\n");
break;
case STMT_PRINT:
if(s->expr) {
if(s->expr->kind == EXPR_LIST) { // multiple things to print
e_cursor = s->expr; // traverse the expr_list
while(e_cursor) {
expr_print_codegen(e_cursor->left, output);
e_cursor = e_cursor->right;
}
}
else { // single thing to print
expr_print_codegen(s->expr, output);
}
}
break;
case STMT_RETURN:
fprintf(output, "\n\t## return statement ##\n");
if (s->expr) {
expr_codegen(s->expr, output);
fprintf(output, "\tMOV %s, %%rax\n", register_name(s->expr->reg));
register_free(s->expr->reg);
fprintf(output, "\tJMP .ret%d\n", ret_count); // return to caller
}
else {
fprintf(output, "\tJMP .ret%d\n", ret_count);
}
fprintf(output, "\t## end return statement ##\n\n");
break;
case STMT_BLOCK:
stmt_codegen(s->body, output);
break;
case STMT_EMPTY:
break;
}
stmt_codegen(s->next, output);
}
