build(build): 拆分子目录 CMakeLists 并规范目标命名

src/frontend/CMakeLists.txt

@@ -0,0 +1,18 @@
+add_library(frontend STATIC
+  AntlrDriver.cpp
+  AstBuilder.cpp
+)
+
+target_link_libraries(frontend PUBLIC
+  build_options
+  ast
+  "${ANTLR4_RUNTIME_TARGET}"
+)
+
+# 自动纳入构建目录中的 ANTLR 生成源码（若存在）
+file(GLOB ANTLR4_GENERATED_SOURCES CONFIGURE_DEPENDS
+  "${ANTLR4_GENERATED_DIR}/*.cpp"
+)
+if(ANTLR4_GENERATED_SOURCES)
+  target_sources(frontend PRIVATE ${ANTLR4_GENERATED_SOURCES})
+endif()