void gen_statement(tree_t *t) {
int local_if_label;
int local_while_label;
int local_for_label;
int num_args;
if (t->type == ARRAY || t->right->type == ARRAY || t->left->type == ARRAY) {
yyerror("Array access not supported");
}
switch(t->type) {
case ASSIGNOP:
// Generate code for expression
gen_label(t->right, 1);
gen_expression(t->right);
fprintf(yyout, "\tmovl\t%%ebx, %%eax\n");
// If this is actually a return statement, then return with correct value in %eax
if(!strcmp(t->left->attribute.variable->name, top_scope->curr->name))
fprintf(yyout, "\tjmp\tsubprog%send\n", top_scope->curr->name);
else {
// Generate code for assignment
gen_assignment(t->left);
}
break;
case IF:
local_if_label = if_label++;
//Generate code for expression
gen_label(t->left, 1);
gen_expression(t->left);
//Compare and jump accordingly
fprintf(yyout, "\tcmpl\t$1, %%ebx\n\tjge\tiftrue%d\n", local_if_label);
//Generate code for else first
if (t->right->right != NULL) {
gen_statement(t->right->right);
fprintf(yyout, "\tjmp\tifend%d\n", local_if_label);
}
//Generate code for true section
fprintf(yyout, "iftrue%d:\n", local_if_label);
gen_statement(t->right->left);
fprintf(yyout, "ifend%d:\n", local_if_label);
break;
case WHILE:
local_while_label = while_label++;
//Plant label for beginning of loop
fprintf(yyout, "beginwhile%d:\n", local_while_label);
//Generate code for expression
gen_label(t->left, 1);
gen_expression(t->left);
//Compare and jump to end if needed
fprintf(yyout, "\tcmpl\t$0, %%ebx\n\tje\tendwhile%d\n", local_while_label);
//Generate code for statements
gen_statement(t->right);
fprintf(yyout, "\tjmp\tbeginwhile%d\n", local_while_label);
fprintf(yyout, "endwhile%d:\n", local_while_label);
break;
case PROCEDURE:
if (!strcmp(t->left->attribute.variable->name, "read"))
gen_read(t->right);
else if (!strcmp(t->left->attribute.variable->name, "write"))
gen_write(t->right);
else if (t->right != NULL) {
// push arguments on the stack
num_args = gen_expression_list(t->right);
fprintf(yyout, "\tcall\tsubprog%s\n", t->left->attribute.variable->name);
// move the top of the stack below args
fprintf(yyout, "\taddl\t$%d, %%esp\n", 4*num_args);
}
else {
fprintf(yyout, "\tcall\tsubprog%s\n", t->left->attribute.variable->name);
}
break;
case COMMA:
// Generate left and right statements
if (t->left->type == ARRAY || t->right->type == ARRAY)
yyerror("Array access not supported");
else {
gen_statement(t->left);
gen_statement(t->right);
}
break;
case FOR:
local_for_label = for_label++;
// Generate assignment
gen_statement(t->left->left);
//Plant label for beginning
fprintf(yyout, "forloop%d:\n", local_for_label);
// Generate expression for TO value
gen_label(t->left->right, 1);
gen_expression(t->left->right);
//Compare and jump to end if needed
if (t->left->left->left->attribute.variable->local_or_parameter == LOCAL)
fprintf(yyout, "\tcmpl\t-%i(%%ebp), %%ebx\n\tjl\tforend%d\n",
t->left->left->left->attribute.variable->offset, local_for_label);
else
fprintf(yyout, "\tcmpl\t-%i(%%ebp), %%ebx\n\tjl\tforend%d\n",
t->left->left->left->attribute.variable->offset, local_for_label);
//Generate code for statements
gen_statement(t->right);
//Increment, jump to top then plant end label
fprintf(yyout, "\tincl\t-%i(%%ebp)\n\tjmp\tforloop%d\nforend%d:\n",
t->left->left->left->attribute.variable->offset,
local_for_label, local_for_label);
break;
default:
fprintf(stderr, "TYPE: %d\n", t->type);
yywarn("Statement not supported");
break;
}
}
int repo_new(repo* rep, const char* newname) {
int err = 0;
// New branches track empty directories. The branch has no old roots.
// It is staging and the current root being staged points to the only
// object already staged: an empty directory.
// Create a string buffer for making paths
char* path = gen_malloc(MAX_PATH_LEN);
if (!path) {
err = -ENOMEM;
goto exit;
}
gen_sprintf(path, "%s/br/%s", rep->repo, newname);
// mkdir <rep->repo>/br/<newname>
err = gen_mkdir(path, (mode_t)0700);
if (err)
goto exit;
// mkdir <rep->repo>/br/<newname>/oldroots
strcat(path, "/oldroots");
err = gen_mkdir(path, (mode_t)0700);
if (err)
goto exit;
// mkdir <rep->repo>/br/<newname>/stage
gen_sprintf(path, "%s/br/%s/stage", rep->repo, newname);
err = gen_mkdir(path, (mode_t)0700);
if (err)
goto exit;
// mkdir <rep->repo>/br/<newname>/stage/objs
strcat(path, "/objs");
err = gen_mkdir(path, (mode_t)0700);
if (err)
goto exit;
// mkdir <rep->repo>/br/<newname>/stage/objs/<nextid>
uint64_t nextid = repo_newid(rep);
gen_sprintf(path, "%s/br/%s/%lu", rep->repo, newname, nextid);
err = gen_mkdir(path, (mode_t)0700);
if (err)
goto exit;
// echo `repo_newid` > <rep->repo>/br/<newname>/stage/root
gen_sprintf(path, "%s/br/%s/root", rep->repo, newname);
int fd = gen_open(path, O_CREAT|O_RDWR, (mode_t)0700);
if (fd < 0) {
err = fd;
goto exit;
}
gen_sprintf(path, "%lu\n", nextid);
int nbytes;
err = gen_write(fd, path, strlen(path), &nbytes);
if (err)
goto exit;
gen_close(fd);
sync();
exit:
gen_free(path);
return err;
}