support bazel complie this project and format code.

basic_content/vptr_vtable/BUILD

@@ -0,0 +1,8 @@
+# please run `bazel run basic_content/vptr_vtable:vptr1`
+load("@rules_cc//cc:defs.bzl", "cc_binary")
+
+cc_binary(
+    name = "vptr1",
+    srcs = ["vptr1.cpp"],
+    copts = ["-std=c++11"]
+)

basic_content/vptr_vtable/vptr1.cpp

@@ -1,12 +1,3 @@
-/**
- * @file vptr1.cpp
- * @brief C++虚函数vptr和vtable
- * 编译：g++ -g -o vptr vptr1.cpp -std=c++11
- * @author 光城
- * @version v1
- * @date 2019-07-20
- */
-
 #include <iostream>
 #include <stdio.h>
 using namespace std;
@@ -16,90 +7,75 @@ using namespace std;
  */
 typedef void (*Fun)();
 
-
 /**
  * @brief 基类
  */
-class Base
-{
-    public:
-        Base(){};
-        virtual void fun1()
-        {
-            cout << "Base::fun1()" << endl;
-        }
-        virtual void fun2()
-        {
-            cout << "Base::fun2()" << endl;
-        }
-        virtual void fun3(){}
-        ~Base(){};
+class Base {
+public:
+  Base(){};
+  virtual void fun1() { cout << "Base::fun1()" << endl; }
+  virtual void fun2() { cout << "Base::fun2()" << endl; }
+  virtual void fun3() {}
+  ~Base(){};
 };
 
-
 /**
  * @brief 派生类
  */
-class Derived: public Base
-{
-    public:
-        Derived(){};
-        void fun1()
-        {
-            cout << "Derived::fun1()" << endl;
-        }
-        void fun2()
-        {
-            cout << "DerivedClass::fun2()" << endl;
-        }
-        ~Derived(){};
+class Derived : public Base {
+public:
+  Derived(){};
+  void fun1() { cout << "Derived::fun1()" << endl; }
+  void fun2() { cout << "DerivedClass::fun2()" << endl; }
+  ~Derived(){};
 };
 
 /**
- * @brief 获取vptr地址与func地址,vptr指向的是一块内存，这块内存存放的是虚函数地址，这块内存就是我们所说的虚表
+ * @brief
+ * 获取vptr地址与func地址,vptr指向的是一块内存，这块内存存放的是虚函数地址，这块内存就是我们所说的虚表
  *
  * @param obj
  * @param offset
  *
- * @return 
+ * @return
  */
-Fun getAddr(void* obj,unsigned int offset)
-{
-    cout<<"======================="<<endl;
-    void* vptr_addr = (void *)*(unsigned long *)obj;  //64位操作系统，占8字节，通过*(unsigned long *)obj取出前8字节，即vptr指针
-    printf("vptr_addr:%p\n",vptr_addr);
+Fun getAddr(void *obj, unsigned int offset) {
+  cout << "=======================" << endl;
+  void *vptr_addr =
+      (void *)*(unsigned long *)obj; // 64位操作系统，占8字节，通过*(unsigned
+                                     // long *)obj取出前8字节，即vptr指针
+  printf("vptr_addr:%p\n", vptr_addr);
 
-    /**
-     * @brief 通过vptr指针访问virtual table，因为虚表中每个元素(虚函数指针)在64位编译器下是8个字节，因此通过*(unsigned long *)vptr_addr取出前8字节，
-     * 后面加上偏移量就是每个函数的地址！
-     */
-    void* func_addr = (void *)*((unsigned long *)vptr_addr+offset);
-    printf("func_addr:%p\n",func_addr);
-    return (Fun)func_addr;
+  /**
+   * @brief 通过vptr指针访问virtual
+   * table，因为虚表中每个元素(虚函数指针)在64位编译器下是8个字节，因此通过*(unsigned
+   * long *)vptr_addr取出前8字节， 后面加上偏移量就是每个函数的地址！
+   */
+  void *func_addr = (void *)*((unsigned long *)vptr_addr + offset);
+  printf("func_addr:%p\n", func_addr);
+  return (Fun)func_addr;
 }
-int main(void)
-{
-    Base ptr;
-    Derived d;
-    Base *pt = new Derived(); // 基类指针指向派生类实例
-    Base &pp = ptr; // 基类引用指向基类实例
-    Base &p = d; // 基类引用指向派生类实例
-    cout<<"基类对象直接调用"<<endl;
-    ptr.fun1();
-    cout<<"基类引用指向基类实例"<<endl;
-    pp.fun1(); 
-    cout<<"基类指针指向派生类实例并调用虚函数"<<endl;
-    pt->fun1();
-    cout<<"基类引用指向派生类实例并调用虚函数"<<endl;
-    p.fun1();
+int main(void) {
+  Base ptr;
+  Derived d;
+  Base *pt = new Derived(); // 基类指针指向派生类实例
+  Base &pp = ptr;           // 基类引用指向基类实例
+  Base &p = d;              // 基类引用指向派生类实例
+  cout << "基类对象直接调用" << endl;
+  ptr.fun1();
+  cout << "基类引用指向基类实例" << endl;
+  pp.fun1();
+  cout << "基类指针指向派生类实例并调用虚函数" << endl;
+  pt->fun1();
+  cout << "基类引用指向派生类实例并调用虚函数" << endl;
+  p.fun1();
 
+  // 手动查找vptr 和 vtable
+  Fun f1 = getAddr(pt, 0);
+  (*f1)();
+  Fun f2 = getAddr(pt, 1);
+  (*f2)();
 
-    // 手动查找vptr 和 vtable
-    Fun f1 = getAddr(pt, 0);
-    (*f1)();
-    Fun f2 = getAddr(pt, 1);
-    (*f2)();
-
-    delete pt;
-    return 0;
+  delete pt;
+  return 0;
 }