feat(lex_parser): 初始化词法解析器模块

新增词法解析器库 `smcc_lex_parser`，包含基础的词法规则解析功能：
- 支持字符、字符串、数字、标识符的解析
- 支持跳过注释、空白符、行尾等辅助函数
- 提供对应的单元测试用例，覆盖各类合法与非法输入情况

该模块依赖 `libcore`，并被 `smcc_lex` 模块引用以支持更上层的词法分析逻辑。

runtime/libcore/include/core_pos.h

@@ -0,0 +1,28 @@
+#ifndef __SMCC_CORE_POS_H__
+#define __SMCC_CORE_POS_H__
+
+#include "core_str.h"
+#include "core_type.h"
+typedef struct {
+    cstring_t name;
+    usize line;
+    usize col;
+    usize offset;
+} core_pos_t;
+
+static inline core_pos_t core_pos_init() {
+    return (core_pos_t){cstring_new(), 1, 1, 0};
+}
+
+static inline void core_pos_next(core_pos_t *pos) {
+    pos->offset++;
+    pos->col++;
+}
+
+static inline void core_pos_next_line(core_pos_t *pos) {
+    pos->offset++;
+    pos->line++;
+    pos->col = 1;
+}
+
+#endif /* __SMCC_CORE_POS_H__ */

runtime/libcore/include/core_str.h

@@ -54,12 +54,15 @@ static inline cstring_t cstring_from_cstr(const char *s) {
  * @param str 要被释放的字符串指针
  */
 static inline void cstring_free(cstring_t *str) {
-    if (str && str->data && str->cap != 0) {
+    if (str == null) {
+        return;
+    }
+    if (str->data != null && str->cap != 0) {
         smcc_free(str->data);
         str->data = null;
-        str->size = 0;
-        str->cap = 0;
     }
+    str->size = 0;
+    str->cap = 0;
 }
 
 /**

runtime/libcore/include/libcore.h

@@ -21,6 +21,7 @@
 #define SMCC_STR(str) _SMCC_STR(str)
 
 #define SMCC_ARRLEN(arr) (sizeof(arr) / sizeof(arr[0]))
+#include <core_pos.h>
 #include <core_str.h>
 #include <core_stream.h>
 #include <core_vec.h>

runtime/libcore/src/stream.c

@@ -69,11 +69,16 @@ static void free_stream(core_stream_t *_stream) {
 
 core_stream_t *core_mem_stream_init(core_mem_stream_t *stream, const char *data,
                                     usize length, cbool need_copy) {
-    if (stream == null || data == NULL || length == 0) {
+    if (stream == null || data == null) {
         LOG_ERROR("param error");
         return null;
     }
 
+    if (length == 0) {
+        LOG_WARN("input memory is empty");
+        need_copy = false;
+    }
+
     stream->owned = need_copy;
     if (need_copy) {
         char *buf = (char *)smcc_malloc(length);

runtime/log/include/log.c

@@ -79,7 +79,11 @@ void init_logger(logger_t *logger, const char *name) {
     log_set_level(logger, LOG_LEVEL_ALL);
 }
 
-logger_t *log_get(const char *name) { return &__default_logger_root; }
+logger_t *log_get(const char *name) {
+    // TODO for -Wunused-parameter
+    (void)name;
+    return &__default_logger_root;
+}
 
 void log_set_level(logger_t *logger, int level) {
     if (logger)
@@ -95,4 +99,8 @@ void log_set_handler(logger_t *logger, log_handler handler) {
         __default_logger_root.handler = handler;
 }
 
-void logger_destroy(logger_t *logger) { return; }
+void logger_destroy(logger_t *logger) {
+    // TODO for -Wunused-parameter
+    (void)logger;
+    return;
+}