[C++/CLI编程宝典][6]IL中间语言

继续上节的ildasm.exe对main.exe的IL中间语言的分析。我们知道我们在main.exe中定义了NativeClass，ValueStruct和RefClass。下面我们将做类型与IL中间语言的一一对应：

1）NativeClass

C++/CLI代码：

// 1 ISOC++
public class NativeClass
{
public:
    NativeClass(std::string str)
    {
        m_str = str;
        std::cout << "ISOC++ 本地类型构造！" << std::endl;
    }
    ~NativeClass()
    {
        std::cout << "ISOC++ 本地类型析构！" << std::endl << std::endl;
    }
    void Print()
    {
        std::cout << m_str << std::endl;
    }
private:
    std::string m_str;
};

IL中间代码:

NativeClass的定义：

上面我们看到了NativeClass的定义，他继承于System.ValueType，但是原本属于该类的成员现在都不在了，原因是ISOC++的class的成员被编译为IL中间代码后变为全局的静态成员，看下图：

2）ValueStruct

ValueStruct的定义：

// 2 C++/CLI
value struct ValueStruct
{
    System::String^ m_str;
    ValueStruct(System::String^ str)
    {
        m_str = str;
        System::Console::WriteLine("托管value值类型构造！");
    }
    // 不能有析构函数
    //~ValueStruct()
    //{
    //    System::Console::WriteLine("托管value值类型析构！");
    //}
    void Print()
    {
        System::Console::WriteLine(m_str);
    }
};

IL中间代码：（可以看到ValueStruct继承于System.ValueType）

3）RefClass

RefClass的定义:

// 3 C++/CLI
ref class RefClass
{
public:
    RefClass(System::String^ str)
    {
        m_str = str;
        System::Console::WriteLine();
        System::Console::WriteLine("托管ref引用类型构造！");
    }
    ~RefClass()
    {
        System::Console::WriteLine("托管ref引用类型析构！");
        System::Console::WriteLine();
    }
    void Print()
    {
        StartPrint();
        System::Console::WriteLine(m_str);
        EndPrint();
    }

    // 属性property，委托delegate和事件event
    property System::String^ Str
    {
        System::String^ get() { return m_str; }
        void set(System::String^ str) { m_str = str; }
    }

    delegate void PrintDelegate(void);
    event PrintDelegate^ StartPrint;
    event PrintDelegate^ EndPrint;

private:
    System::String^ m_str;    
};

IL中间代码: (可以看到RefClass继承于System.IDisposable)

4）main函数

main函数代码：

void StartPrint()
{
    System::Console::WriteLine("Print开始事件，马上开始Print函数调用！");
}
void EndPrint()
{
    System::Console::WriteLine("Print结束事件，Print函数调用结束！");
}

void main()
{
    NativeClass* pNC = new NativeClass("你好，我是ISOC++本地类型！");
    pNC->Print();
    delete pNC;

    ValueStruct vs("你好，我是托管value值类型！");
    vs.Print();
    
    RefClass^ hRC = gcnew RefClass("你好，我是托管ref引用类型！");
    hRC->StartPrint += gcnew RefClass::PrintDelegate(StartPrint);
    hRC->EndPrint += gcnew RefClass::PrintDelegate(EndPrint);
    hRC->Print();
    hRC->Str = "你好，我是托管ref引用类型！现在正通过property属性修改成员feild字段！";
    hRC->Print();
    delete hRC; 

}

IL中间代码main的函数头(可以看到被编译为全局的静态函数)：

具体的main实现：

.method assembly static int32 modopt([mscorlib]System.Runtime.CompilerServices.CallConvCdecl) 
        main() cil managed
{
  .vtentry 1 : 1
  // Code size       200 (0xc8)
  .maxstack  3
  .locals (class RefClass V_0,
           valuetype NativeClass* V_1,
           class [mscorlib]System.IDisposable V_2,
           valuetype NativeClass* V_3,
           valuetype NativeClass* V_4,
           valuetype NativeClass* modopt([mscorlib]System.Runtime.CompilerServices.IsConst) modopt([mscorlib]System.Runtime.CompilerServices.IsConst) V_5,
           int32 V_6,
           void* V_7,
           valuetype NativeClass* V_8,
           valuetype std.'basic_string<char,std::char_traits<char>,std::allocator<char> >'* modopt([mscorlib]System.Runtime.CompilerServices.IsConst) modopt([mscorlib]System.Runtime.CompilerServices.IsConst) V_9,
           valuetype std.'basic_string<char,std::char_traits<char>,std::allocator<char> >'* V_10,
           valuetype ValueStruct V_11,
           valuetype std.'basic_string<char,std::char_traits<char>,std::allocator<char> >' V_12)
  IL_0000:  ldnull
  IL_0001:  stloc.0
  IL_0002:  ldc.i4.s   28
  IL_0004:  call       void* modopt([mscorlib]System.Runtime.CompilerServices.CallConvCdecl) new(uint32)
  IL_0009:  stloc.1
  .try
  {
    IL_000a:  ldloc.1
    IL_000b:  brfalse.s  IL_002b
    IL_000d:  ldloca.s   V_12
    IL_000f:  stloc.s    V_10
    IL_0011:  ldloc.s    V_10
    IL_0013:  ldsflda    valuetype '<CppImplementationDetails>'.$ArrayType$$$BY0BL@$$CBD modopt([mscorlib]System.Runtime.CompilerServices.IsConst) '?A0x3ea463b6.unnamed-global-1'
    IL_0018:  call       valuetype std.'basic_string<char,std::char_traits<char>,std::allocator<char> >'* modopt([mscorlib]System.Runtime.CompilerServices.CallConvThiscall) 'std.basic_string<char,std::char_traits<char>,std::allocator<char> >.{ctor}'(valuetype std.'basic_string<char,std::char_traits<char>,std::allocator<char> >'* modopt([mscorlib]System.Runtime.CompilerServices.IsConst) modopt([mscorlib]System.Runtime.CompilerServices.IsConst),
                                                                                                                                                                                                                                                          int8 modopt([mscorlib]System.Runtime.CompilerServices.IsSignUnspecifiedByte) modopt([mscorlib]System.Runtime.CompilerServices.IsConst)*)
    IL_001d:  stloc.s    V_9
    IL_001f:  ldloc.1
    IL_0020:  ldloc.s    V_9
    IL_0022:  call       valuetype NativeClass* modopt([mscorlib]System.Runtime.CompilerServices.CallConvThiscall) 'NativeClass.{ctor}'(valuetype NativeClass* modopt([mscorlib]System.Runtime.CompilerServices.IsConst) modopt([mscorlib]System.Runtime.CompilerServices.IsConst),
                                                                                                                                        valuetype std.'basic_string<char,std::char_traits<char>,std::allocator<char> >' modreq([mscorlib]System.Runtime.CompilerServices.IsCopyConstructed)*)
    IL_0027:  stloc.s    V_5
    IL_0029:  br.s       IL_002e
    IL_002b:  ldc.i4.0
    IL_002c:  stloc.s    V_5
    IL_002e:  ldloc.s    V_5
    IL_0030:  stloc.s    V_8
    IL_0032:  leave.s    IL_003b
  }  // end .try
  fault
  {
    IL_0034:  ldloc.1
    IL_0035:  call       void modopt([mscorlib]System.Runtime.CompilerServices.CallConvCdecl) delete(void*)
    IL_003a:  endfinally
  }  // end handler
  IL_003b:  ldloc.s    V_8
  IL_003d:  stloc.s    V_4
  IL_003f:  ldloc.s    V_4
  IL_0041:  call       void modopt([mscorlib]System.Runtime.CompilerServices.CallConvThiscall) NativeClass.Print(valuetype NativeClass* modopt([mscorlib]System.Runtime.CompilerServices.IsConst) modopt([mscorlib]System.Runtime.CompilerServices.IsConst))
  IL_0046:  ldloc.s    V_4
  IL_0048:  stloc.3
  IL_0049:  ldloc.3
  IL_004a:  brfalse.s  IL_0057
  IL_004c:  ldloc.3
  IL_004d:  ldc.i4.1
  IL_004e:  call       void* modopt([mscorlib]System.Runtime.CompilerServices.CallConvThiscall) NativeClass.__delDtor(valuetype NativeClass* modopt([mscorlib]System.Runtime.CompilerServices.IsConst) modopt([mscorlib]System.Runtime.CompilerServices.IsConst),
                                                                                                                      uint32)
  IL_0053:  stloc.s    V_7
  IL_0055:  br.s       IL_005a
  IL_0057:  ldc.i4.0
  IL_0058:  stloc.s    V_7
  IL_005a:  ldloca.s   V_11
  IL_005c:  ldstr      bytearray (60 4F 7D 59 0C FF 11 62 2F 66 58 62 A1 7B 76 00   // `O}Yb/fXb.{v.
                                  61 00 6C 00 75 00 65 00 3C 50 7B 7C 8B 57 01 FF ) // a.l.u.e.<P{|.W..
  IL_0061:  call       instance void ValueStruct::.ctor(string)
  IL_0066:  ldloca.s   V_11
  IL_0068:  call       instance void ValueStruct::Print()
  IL_006d:  ldstr      bytearray (60 4F 7D 59 0C FF 11 62 2F 66 58 62 A1 7B 72 00   // `O}Yb/fXb.{r.
                                  65 00 66 00 15 5F 28 75 7B 7C 8B 57 01 FF )       // e.f.._(u{|.W..
  IL_0072:  newobj     instance void RefClass::.ctor(string)
  IL_0077:  stloc.0
  IL_0078:  ldloc.0
  IL_0079:  ldnull
  IL_007a:  ldftn      void modopt([mscorlib]System.Runtime.CompilerServices.CallConvCdecl) StartPrint()
  IL_0080:  newobj     instance void RefClass/PrintDelegate::.ctor(object,
                                                                   native int)
  IL_0085:  call       instance void RefClass::add_StartPrint(class RefClass/PrintDelegate)
  IL_008a:  ldloc.0
  IL_008b:  ldnull
  IL_008c:  ldftn      void modopt([mscorlib]System.Runtime.CompilerServices.CallConvCdecl) EndPrint()
  IL_0092:  newobj     instance void RefClass/PrintDelegate::.ctor(object,
                                                                   native int)
  IL_0097:  call       instance void RefClass::add_EndPrint(class RefClass/PrintDelegate)
  IL_009c:  ldloc.0
  IL_009d:  call       instance void RefClass::Print()
  IL_00a2:  ldloc.0
  IL_00a3:  ldstr      bytearray (60 4F 7D 59 0C FF 11 62 2F 66 58 62 A1 7B 72 00   // `O}Yb/fXb.{r.
                                  65 00 66 00 15 5F 28 75 7B 7C 8B 57 01 FF B0 73   // e.f.._(u{|.Ws
                                  28 57 63 6B 1A 90 C7 8F 70 00 72 00 6F 00 70 00   // (Wck.p.r.o.p.
                                  65 00 72 00 74 00 79 00 5E 5C 27 60 EE 4F 39 65   // e.r.t.y.^\'`.O9e
                                  10 62 58 54 66 00 65 00 69 00 6C 00 64 00 57 5B   // .bXTf.e.i.l.d.W[
                                  B5 6B 01 FF )                                     // .k..
  IL_00a8:  call       instance void RefClass::set_Str(string)
  IL_00ad:  ldloc.0
  IL_00ae:  call       instance void RefClass::Print()
  IL_00b3:  ldloc.0
  IL_00b4:  stloc.2
  IL_00b5:  ldloc.2
  IL_00b6:  brfalse.s  IL_00c3
  IL_00b8:  ldloc.2
  IL_00b9:  callvirt   instance void [mscorlib]System.IDisposable::Dispose()
  IL_00be:  ldc.i4.0
  IL_00bf:  stloc.s    V_6
  IL_00c1:  br.s       IL_00c6
  IL_00c3:  ldc.i4.0
  IL_00c4:  stloc.s    V_6
  IL_00c6:  ldc.i4.0
  IL_00c7:  ret
} // end of method 'Global Functions'::main

读者可以将以上的源代码和IL对照，达到对IL的简单理解！

完！