/*create type of a variable*/
struct type_descriptor*
create_type(struct tree_node* specifier_node){
assert(specifier_node -> unit_code == Specifier);
int type_code = get_type_code_from_specifier(specifier_node);
struct struct_descriptor* sd;
if(type_code == TYPE_INT || type_code == TYPE_FLOAT){
sd = NULL;
}
if(type_code == TYPE_STRUCT){
//Specifier -> StructSpecifier
struct tree_node* structspecifier_node = specifier_node -> child;
if(structspecifier_node -> child -> sibling -> unit_code == Tag){ //exist struct
char *struct_name = structspecifier_node -> child -> sibling -> child -> unit_value;
sd = find_struct(struct_table_head, struct_name);
if(sd == NULL){
printf("Error Type 17 at line %d : Undefined struct %s\n", specifier_node -> lineno, struct_name );
semantic_error_flag = true;
return NULL;
}
}
else{ //new struct
sd = create_structure(structspecifier_node);
}
}
return create_type_descriptor(type_code, sd);
}
/*create a structure and add it into the struct list
*structure defined by structspecifier node in syntax tree*/
struct struct_descriptor*
create_structure(struct tree_node* structspecifier_node){
assert(structspecifier_node -> unit_code == StructSpecifier);
struct tree_node* opttag_node = structspecifier_node -> child -> sibling;
char* struct_name;
if(structspecifier_node -> child -> sibling -> child != NULL){ //OptTag !-> empty
struct_name = opttag_node -> child -> unit_value; //ID node has a value
/*check struct name repeat*/
if((find_struct(struct_table_head, struct_name) != NULL) ||
(find_var(var_table_head, struct_name) != NULL)){
printf("Error type 16 at line %d: Struct name redefine\n", structspecifier_node -> lineno);
semantic_error_flag = true;
return NULL;
}
}
else
struct_name = ""; //empty struct name
struct tree_node* deflist_node = opttag_node -> sibling -> sibling;
struct struct_descriptor* new_struct_descriptor = create_struct_descriptor(struct_name);
new_struct_descriptor -> member_num = init_member_list(new_struct_descriptor -> member_list_head, deflist_node);
add_struct(struct_table_head, new_struct_descriptor);
return new_struct_descriptor;
}
symbol_t *
build_struct (int su, symbol_t *tag, symtab_t *symtab, type_t *type)
{
symbol_t *sym = find_struct (su, tag, type);
symbol_t *s;
symtab->parent = 0; // disconnect struct's symtab from parent scope
if (sym->table == current_symtab && sym->type->t.symtab) {
error (0, "%s defined as wrong kind of tag", tag->name);
return sym;
}
for (s = symtab->symbols; s; s = s->next) {
if (s->sy_type != sy_var)
continue;
if (su == 's') {
s->s.offset = symtab->size;
symtab->size += type_size (s->type);
} else {
int size = type_size (s->type);
if (size > symtab->size)
symtab->size = size;
}
}
if (!type)
sym->type = find_type (sym->type); // checks the tag, not the symtab
sym->type->t.symtab = symtab;
if (!type && sym->type->type_def->external) //FIXME should not be necessary
sym->type->type_def = qfo_encode_type (sym->type);
return sym;
}
//!
//! Either prints help messages or runs command-specific validator
//!
//! @param[in] index
//! @param[in] this_cmd
//! @param[in] params
//! @param[in] next_cmd
//!
//! @return A pointer to the command structure if valid otherwise NULL is returned
//!
//! @pre
//!
//! @post
//!
static imager_command *validate_cmd(int index, char *this_cmd, imager_param * params, char *next_cmd)
{
int i = 0;
char help = '\0';
char *cmd = NULL;
const char **p = NULL;
imager_command *cmd_struct = NULL;
imager_request *req = NULL;
if (this_cmd == NULL)
return NULL;
cmd = this_cmd;
// see if it is a help request
if (strcmp(cmd, "help") == 0) {
help = 1;
if (next_cmd == NULL) { // not specific
fprintf(stderr, "supported commands:\n");
for (i = 0; i < (sizeof(known_cmds) / sizeof(imager_command)); i++) {
fprintf(stderr, "\t%s\n", known_cmds[i].name);
}
exit(0);
} else { // help for a specific command
cmd = next_cmd;
}
}
// find the function pointers for the command
if ((cmd_struct = find_struct(cmd)) == NULL)
err("command '%s' not found", cmd);
// print command-specific help
if (help) {
p = cmd_struct->parameters();
if (p == NULL || *p == NULL) {
fprintf(stderr, "command '%s' has no parameters\n", cmd_struct->name);
} else {
fprintf(stderr, "parameters for '%s' (* - mandatory):\n", cmd_struct->name);
while (*p && *(p + 1)) {
fprintf(stderr, "%18s - %s\n", *p, *(p + 1));
p += 2;
}
}
exit(0);
}
// fill out the request struct and pass to the validator
req = &reqs[index];
req->cmd = cmd_struct;
req->params = params;
req->index = index;
req->internal = NULL;
if (cmd_struct->validate(req))
err("incorrect parameters or missing dependencies for command '%s'", cmd_struct->name);
return cmd_struct;
}
void sub(t_glob *glob, t_champ *champ, int *args, int *type)
{
op_t *ins;
int first_r;
int second_r;
glob = glob;
type = type;
first_r = champ->reg[(args[0] - 1)];
second_r = champ->reg[(args[1] - 1)];
if (champ != NULL)
{
ins = find_struct(5);
champ->cycle_next_ins = ins->nbr_cycles;
champ->reg[(args[2] - 1)] = first_r - second_r;
champ->carry = '1';
}
}
/*create a variable and add it into a var list
*var defined by the specifier and vardec nodes in syntax tree*/
struct var_descriptor*
create_variable(struct tree_node* specifier_node, struct tree_node* vardec_node, struct var_descriptor* head, bool is_member_var){
struct type_descriptor* var_type = create_type(specifier_node);
if(var_type == NULL)
return NULL;
char* var_name = find_id_node_in_vardec(vardec_node) -> unit_value;
struct array_descriptor* var_array = create_array_descriptor_by_vardec(vardec_node);
struct var_descriptor* new_var = create_var_descriptor(var_name, var_type, var_array);
if(find_var(head, var_name) == NULL && find_struct(struct_table_head, var_name) == NULL){
add_var(head, new_var);
return new_var;
}
else{
if(is_member_var)
printf("Error type 15 at line %d: member variable \'%s\' redefine\n", vardec_node -> lineno, var_name);
else
printf("Error type 3 at line %d: variable \'%s\' redefine\n", vardec_node -> lineno, var_name);
semantic_error_flag = true;
return NULL;
}
}
void handle_postfix_expr(node *n) {
int prev_lvalue;
/* the first child is always grabbed as a reference */
prev_lvalue = LVALUE;
LVALUE = 1;
handle(n->children[0]);
LVALUE = prev_lvalue;
if (strcmp(n->children[1]->id, "inc") == 0) {
if (LVALUE) {
lerr(n->line, "[code_gen] invalid lvalue\n");
} else {
/* post increment */
e("lw $t1, 0($t0)\n");
e("addiu $t2, $t1, 1\n");
e("sw $t2, 0($t0)\n");
e("move $t0, $t1\n");
}
} else if (strcmp(n->children[1]->id, "dec") == 0) {
if (LVALUE) {
lerr(n->line, "[code_gen] invalid lvalue\n");
} else {
/* post deccrement */
e("lw $t1, 0($t0)\n");
e("addiu $t2, $t1, -1\n");
e("sw $t2, 0($t0)\n");
e("move $t0, $t1\n");
}
} else if (strcmp(n->children[1]->id, "argument_expr_list") == 0) {
/* function call */
handle(n->children[1]);
e("call %s\n", n->children[0]->id);
e("addiu $sp, $sp, %d\n", params * WORD);
e("move $t0, $v0\n");
params = 0;
} else if (strcmp(n->children[1]->id, "paren") == 0) {
/* function call without arguments */
e("call %s\n", n->children[0]->id);
e("move $t0, $v0\n");
} else if (strcmp(n->children[1]->id, "expression") == 0) {
/* array index */
if (last_symbol != NULL) {
if (last_symbol->attr & ATTR_POINTER) {
e("lw $t0, 0($t0)\n");
}
}
push("$t0");
prev_lvalue = LVALUE;
LVALUE = 0;
handle(n->children[1]); /* the offset in the array */
LVALUE = prev_lvalue;
pop("$t1");
e("sll $t0, $t0, 2\n"); /*TODO: not all array indexes are multiples of 4! */
e("addu $t0, $t0, $t1\n");
if (!LVALUE) { /* dereference it */
e("lw $t0, 0($t0)\n");
}
}
else if (strcmp(n->children[1]->id, "dot") == 0)
{
/* puts address of struct member into $t0 */
// offsets of struct and member within struct
int member_offset = 0;
// struct name
char *struct_id = n->children[0]->id;
// member name
char *member_id = n->children[2]->id;
// struct symbol table entry
symbol *sym = find_symbol(n->children[0]->t, struct_id);
// struct type
char *struct_type = sym->type;
// struct table entry
struct_table *curr = find_struct(struct_type);
if(curr == NULL)
{
lerr(n->line, "[code_gen] could not find struct type: %s\n", struct_type);
}
// Struct symbol table
symbol_table *struct_sym_tbl = curr->s;
// Struct member symbol pointer
symbol *cur_sym;
/*
// DEBUG: Print struct identifier and member identifier
printf("\t* Struct Name: %s, Member Name: %s\n", struct_id, member_id);
// DEBUG: Print member name and type
printf("\t\t* Attribute: %X, Type %s\n", sym->attr, sym->type);
*/
// if struct is a union (ATTR_UNION == 0x2000) then skip offset code
if(sym->attr & ATTR_STRUCT)
{
// Determine member offset in struct
cur_sym = struct_sym_tbl->s;
while (strcmp(cur_sym->value, member_id) != 0) {
if (cur_sym == NULL)
lerr(n->line, "[code_gen] could not find member, %s, in struct: %s\n", member_id, struct_type);
cur_sym = cur_sym->up;
member_offset += 4;
}
e("addiu $t0, $t0, %d # offset of member: %s\n", member_offset, member_id);
}
else if(sym->attr & ATTR_UNION)
{
// No member offset is currently required for unions because all members are the same size and word aligned
}
else
{
lerr(n->line, "[code_gen] %s is not a struct or union so '.' cannot be used\n", struct_id);
}
}
else if (strcmp(n->children[1]->id, "ptr") == 0)
{
/* puts value located in address of struct member into $t0 */
// offsets of struct and member within struct
int member_offset = 0;
// struct name
char *struct_id = n->children[0]->id;
// member name
char *member_id = n->children[2]->id;
// struct symbol table entry
symbol *sym = find_symbol(n->children[0]->t, struct_id);
// struct type
char *struct_type = sym->type;
// struct table entry
struct_table *curr = find_struct(struct_type);
if(curr == NULL)
{
lerr(n->line, "[code_gen] could not find struct type: %s\n", struct_type);
}
// Struct symbol table
symbol_table *struct_sym_tbl = curr->s;
// Struct member symbol pointer
symbol *cur_sym;
// if struct is a union (ATTR_UNION == 0x2000) then skip offset code
if(sym->attr & ATTR_STRUCT)
{
// Determine member offset in struct
cur_sym = struct_sym_tbl->s;
while (strcmp(cur_sym->value, member_id) != 0) {
if (cur_sym == NULL)
lerr(n->line, "[code_gen] could not find member, %s, in struct: %s\n", member_id, struct_type);
cur_sym = cur_sym->up;
member_offset += 4;
}
e("addiu $t0, $t0, %d # offset of member: %s\n", member_offset, member_id);
e("lw $t0, 0($t0)\t# load value of %s->%s\n", struct_id, member_id);
//pop("$t1");
}
else if(sym->attr & ATTR_UNION)
{
// Mask only applicable bits of variable types that don't use full word (i.e. char, short, etc.)
e("lw $t0, 0($t0)\t# load value of %s->%s\n", struct_id, member_id);
cur_sym = find_symbol(struct_sym_tbl, member_id);
if( strcmp(cur_sym->type, "char") == 0 )
{
e("andi $t0, $t0, 0xFF # Member is a char, Truncate value to 8 bits\n");
}
else if( strcmp(cur_sym->type, "short") == 0 )
{
e("andi $t0, $t0, 0xFF # Member is a short, Truncate value to 8 bits\n");
}
//pop("$t1");
}
else
{
lerr(n->line, "[code_gen] %s is not a struct or union so '->' cannot be used\n", struct_id);
}
// Old implementation without union
/*
// offsets of struct and member within struct
int member_offset = 0;
// struct name
char *struct_id = n->children[0]->id;
// struct type
char *struct_type = find_symbol(n->children[0]->t, struct_id)->type;
// member name
char *member_id = n->children[2]->id;
// struct symbol table
struct_table *curr = find_struct(struct_type);
if(curr == NULL)
{
lerr(n->line, "[code_gen] could not find struct type: %s\n", struct_type);
}
// Determine member offset in struct
symbol *cur_sym = curr->s->s;
while (strcmp(cur_sym->value, member_id) != 0) {
if (cur_sym == NULL)
lerr(n->line, "[code_gen] could not find member, %s, in struct type: %s\n", member_id, struct_type);
cur_sym = cur_sym->up;
member_offset += 4;
}
e("addiu $t0, $t0, %d\t# offset of member: %s\n", member_offset, member_id);
e("lw $t0, 0($t0)\t# load value of %s->%s", struct_id, member_id);
pop("$t1");
*/
}
else
{
// Debug: display id of child that is not implemented
// printf("id not implemented: %s\n", n->children[1]->id);
lerr(n->line, "[code_gen] postfix expressions not fully implemented\n");
}
}
