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#include "as_analyzer.h"
#include <stddef.h>
#include <string.h>
const char * compose_section_label(struct allocator * alct, const char * section, const char * name) {
size_t section_len = strlen(section);
size_t name_len = strlen(name);
size_t sz = section_len + name_len;
char * buf = allocate(alct, sz + 1);
memcpy(buf, section, section_len);
memcpy(buf + section_len, name, name_len);
buf[sz] = '\0';
return buf;
}
void process_section_label(struct allocator * alct, struct prog * prog) {
const char * section = "";
struct stmt ** stmts = prog->stmts->stmts;
for (size_t i = 0; ; i++) {
if (stmts[i] == NULL) break;
if (stmts[i]->label == NULL) continue;
const char* name = stmts[i]->label->name;
if (name[0] == '.') {
stmts[i]->label->name = compose_section_label(alct, section, name);
} else {
section = name;
continue;
}
}
}
size_t instr_size(struct instr * instr) {
return op_size(instr->op);
}
struct sym_table new_sym_table(struct allocator * alct) {
struct sym_table tbl;
tbl.cap = 16;
tbl.size = 0;
tbl.buf = allocate(alct, sizeof(struct sym_table_entry) * 16);
return tbl;
}
void sym_table_add(struct allocator * alct, struct sym_table* tbl, const char* name, int pos) {
if (tbl->cap == tbl->size) {
void *old_buf = tbl->buf;
tbl->buf = allocate(alct, sizeof(struct sym_table_entry) * tbl->cap * 2);
memcpy(tbl->buf, old_buf, sizeof(struct sym_table_entry) * tbl->cap);
tbl->cap = tbl->cap * 2;
}
tbl->buf[tbl->size] = (struct sym_table_entry){.name = name, .offset = pos,};
tbl->size += 1;
}
int sym_table_lookup(sym_table* tbl, const char* name) {
for (int i = 0; i < tbl->size; i++) {
if (strcmp(name, tbl->buf[i].name) == 0) {
return tbl->buf[i].offset;
}
}
return -1;
}
struct sym_table analyze_prog(struct allocator * alct, struct prog * prog) {
process_section_label(alct, prog);
struct stmt * * stmts = prog->stmts->stmts;
struct sym_table tbl = new_sym_table(alct);
size_t cur_pos = 0;
for (int i = 0; ; i++) {
if (stmts[i] == NULL) break;
struct stmt * stmt = stmts[i];
if (stmt->label) {
sym_table_add(alct, &tbl, stmt->label->name, cur_pos);
}
if (stmt->instr) {
cur_pos += instr_size(stmt->instr);
}
}
return tbl;
}
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