feat add func call and rewrite codes

ccompiler/frontend/lexer/token.c

@@ -0,0 +1,86 @@
+#define FRONTEND_IMPLEMENTATION
+#include "../frontend.h"
+#include "token.h"
+
+#define ROUND_IDX(idx) ((idx) % tokbuf->cap)
+
+tok_t* pop_tok(tok_buf_t* tokbuf) {
+    if (tokbuf->size == 0) {
+        error("no token to pop");
+        return NULL;
+    }
+    int idx = tokbuf->cur;
+    tokbuf->cur = ROUND_IDX(idx + 1);
+    tokbuf->size -= 1;
+    return tokbuf->buf + idx;
+}
+
+void flush_peek_tok(tok_buf_t* tokbuf) {
+    tokbuf->peek = tokbuf->cur;
+}
+
+void init_tokbuf(tok_buf_t *tokbuf, void *stream, get_tokbuf_func gettok) {
+    tokbuf->cur = 0;
+    tokbuf->end = 0;
+    tokbuf->peek = 0;
+    tokbuf->size = 0;
+    tokbuf->stream = stream;
+    tokbuf->gettok = gettok;
+    tokbuf->buf = NULL;
+    tokbuf->cap = 0;
+}
+
+tok_t *peek_tok(tok_buf_t *tokbuf)
+{
+    int idx = tokbuf->peek;
+    idx = ROUND_IDX(idx + 1);
+    if (tokbuf->size >= tokbuf->cap) {
+        error("peek too deep, outof array size");
+    }
+    if (tokbuf->peek == tokbuf->end) {
+        if (tokbuf->size == tokbuf->cap) {
+            error("peek_tok buffer overflow");
+        }
+        if (tokbuf->gettok == NULL) {
+            error("peek_tok can not got tok");
+        }
+        tokbuf->gettok(tokbuf->stream, &(tokbuf->buf[idx]));
+        tokbuf->size++;
+        tokbuf->end = idx;
+    }
+    
+    tokbuf->peek = idx;
+    return &(tokbuf->buf[idx]);
+}
+
+tok_type_t peek_tok_type(tok_buf_t* tokbuf) {
+    return peek_tok(tokbuf)->type;
+}
+
+int expect_pop_tok(tok_buf_t* tokbuf, tok_type_t type) {
+    flush_peek_tok(tokbuf);
+    tok_t* tok = peek_tok(tokbuf);
+    if (tok->type != type) {
+        error("expected tok: %s, got %s", get_tok_name(type), get_tok_name(tok->type));
+    } else {
+        pop_tok(tokbuf);
+    }
+    return 0;
+}
+
+// 生成字符串映射（根据需求选择#str或#name）
+static const char* token_strings[] = {
+    // 普通token使用#str
+    #define X(str, tok) [tok] = #str,
+    TOKEN_TABLE
+    #undef X
+    
+    // 关键字使用#name
+    #define X(name, std, tok) [tok] = #name,
+    KEYWORD_TABLE
+    #undef X
+};
+
+const char* get_tok_name(tok_type_t type) {
+    return token_strings[type];
+}