C＃的拆解：为什么DUMPBIN本土code，从调试的拆卸如此不同？ [英] disassembly of C#: why is DUMPBIN native code so different from Debug's Disassembly?
问题描述
想这是我的计划simpleCsharp.exe：
Suppose this is my program simpleCsharp.exe:
namespace simpleCsharp
{
public class Program
{
public static int Main(string[] args)
{
uint x = 0xFEFEFE;
uint y = 0xEEEEEE;
uint z;
uint[] list = { 0, 1, 2, 4, 8 };
uint[] array = { 0xA, 0xB, 0xC, 0xD };
z = x + y + list[2] + array[1];
z = z - (y << 1);
return 0;
}
}
}
如果我查看调试的反汇编窗口中一个简单的C＃程序的反汇编中，本土$ C $Ç输出至少有一定的道理。例如，这里是主要的调试的拆卸与优化上：
If I view the disassembly of a simple C# program in Debug's Disassembly window, the native code output at least makes some sense. For example, here is the Debug's disassembly of Main, with Optimization on:
uint x = 0xFEFEFE;
00000000 push ebp
00000001 mov ebp,esp
00000003 sub esp,28h
00000006 xor eax,eax
00000008 mov dword ptr [ebp-14h],eax
0000000b mov dword ptr [ebp-18h],eax
0000000e mov dword ptr [ebp-4],ecx
00000011 cmp dword ptr ds:[037D14ACh],0
00000018 je 0000001F
0000001a call 763B370F
0000001f xor edx,edx
00000021 mov dword ptr [ebp-0Ch],edx
00000024 xor edx,edx
00000026 mov dword ptr [ebp-1Ch],edx
00000029 xor edx,edx
0000002b mov dword ptr [ebp-20h],edx
0000002e xor edx,edx
00000030 mov dword ptr [ebp-8],edx
00000033 xor edx,edx
00000035 mov dword ptr [ebp-10h],edx
00000038 mov dword ptr [ebp-8],0FEFEFEh
uint y = 0xEEEEEE;
0000003f mov dword ptr [ebp-0Ch],0EEEEEEh
uint z;
uint[] list = { 0, 1, 2, 4, 8 };
00000046 mov edx,5
0000004b mov ecx,79882916h
00000050 call FD95FD70
00000055 mov dword ptr [ebp-24h],eax
00000058 lea ecx,[ebp-14h]
0000005b mov edx,37D25E0h
00000060 call 761A4716
00000065 lea eax,[ebp-14h]
00000068 push dword ptr [eax]
0000006a mov ecx,dword ptr [ebp-24h]
0000006d call 761A47F3
00000072 mov eax,dword ptr [ebp-24h]
00000075 mov dword ptr [ebp-1Ch],eax
uint[] array = { 0xA, 0xB, 0xC, 0xD };
00000078 mov edx,4
0000007d mov ecx,79882916h
00000082 call FD95FD70
00000087 mov dword ptr [ebp-28h],eax
0000008a lea ecx,[ebp-18h]
0000008d mov edx,37D25ECh
00000092 call 761A4716
00000097 lea eax,[ebp-18h]
0000009a push dword ptr [eax]
0000009c mov ecx,dword ptr [ebp-28h]
0000009f call 761A47F3
000000a4 mov eax,dword ptr [ebp-28h]
000000a7 mov dword ptr [ebp-20h],eax
z = x + y + list[2] + array[1];
000000aa mov eax,dword ptr [ebp-8]
000000ad add eax,dword ptr [ebp-0Ch]
000000b0 mov edx,dword ptr [ebp-1Ch]
000000b3 cmp dword ptr [edx+4],2
000000b7 ja 000000BE
000000b9 call 763B6900
000000be add eax,dword ptr [edx+10h]
000000c1 mov edx,dword ptr [ebp-20h]
000000c4 cmp dword ptr [edx+4],1
000000c8 ja 000000CF
000000ca call 763B6900
000000cf add eax,dword ptr [edx+0Ch]
000000d2 mov dword ptr [ebp-10h],eax
z = z - (y << 1);
000000d5 mov eax,dword ptr [ebp-0Ch]
000000d8 add eax,eax
000000da sub dword ptr [ebp-10h],eax
return 0;
000000dd xor eax,eax
000000df mov esp,ebp
000000e1 pop ebp
000000e2 ret
不过，如果我在相同的C＃程序集运行DUMPBIN（含调试信息=无，所以它不只是显示字节），即
However, if I run DUMPBIN on the same C# assembly (with Debug Info = "None" so it doesn't just show bytes), i.e.
dumpbin "simpleCsharp.exe" /disasm /out:"simpleCsharp_dump.txt"
生成的文件在本地code输出甚至不接近于我在调试的拆卸查看。我没有看到调试的拆卸从DUMPBIN在文件中甚至单个指令或值。因此，2号线的本土code（上图）是无处可寻。这是我是否对从Visual Studio（2010年）产生的组件运行DUMPBIN的情况下，或我使用的 ngen.exe ，以生成一个原生图像，和本机镜像文件上运行DUMPBIN simpleCsharp.ni.exe。
the native code output in the generated file doesn't even closely resemble what I viewed in Debug's Disassembly. I don't see even a single instruction or value from the Debug's Disassembly in the file from dumpbin. So the 2 lines of native code (above) are nowhere to be found. This is the case whether I run dumpbin on the assembly generated from Visual Studio (2010) or I use ngen.exe to generate a native image, and run dumpbin on the native image file simpleCsharp.ni.exe.
优化是在的调试，构筑将发布，我运行调试的程序集，我给NGEN的组件之间的唯一区别，就是调试信息=无。
Optimization is on in Debug, and build is set to Release, the only difference between the assembly I run Debug on, and the assembly I give to ngen, is Debug Info = "None".
dumpbin simpleCsharp.ni.exe /disasm
下面是我的原生图像文件上运行DUMPBIN的simpleCsharp程序的反汇编：
Here is the disassembly of the simpleCsharp program when I run dumpbin on the native image file:
<一个href="https://docs.google.com/leaf?id=0B9u9yFU99BOcYjNmNGRmNTItZjQ0NC00YmI0LWEyZTQtNjdkNDdhYTc2MmNm&hl=en" rel="nofollow">https://docs.google.com/leaf?id=0B9u9yFU99BOcYjNmNGRmNTItZjQ0NC00YmI0LWEyZTQtNjdkNDdhYTc2MmNm&hl=en
我至少希望看到的数量FEFEFE或EEEEEE显示在DUMPBIN输出的地方，而且它出现在调试拆卸。
I would at least expect to see the number FEFEFE or EEEEEE show up in the output of dumpbin somewhere, and it does show up in Debug Disassembly.
可能有人请解释为什么我看不到的一个的线调试的拆卸code从原始图像文件输出的DUMPBIN，出于同样的计划？如果是因为优化了，你会介意让一个小细节？
Could someone please explain why I don't see one line of Debug's disassembly code in the dumpbin output from the native image file, for the same program? If it's because of optimization, would you mind giving a little detail?
感谢
推荐答案
正在忘记了刚刚即时编译器。一集不包含机code，它是在运行时通过从IL在装配抖动产生的。你可以看一下白细胞介素与像程序Ildasm.exe或反思的工具集。 DUMPBIN.EXE具有较差的支持，它可以转储CLR头，仅此而已。
You are forgetting about the just-in-time compiler. An assembly doesn't contain machine code, it is generated at runtime by the jitter from the IL in the assembly. You can look at the IL in the assembly with tools like ildasm.exe or Reflector. Dumpbin.exe has poor support, it can dump the CLR header, that's about it.
要注意的是在NGEN-ED映像包含机器code表示进行优化的抖动。这种优化改变机器codeA很大。优化是默认关闭的调试器。看到它，你必须调试发布版本和修改调试器选项。工具+选项，调试，常规，取消选中选项中的模块负载燮preSS JIT优化。另外注意的是，产生的code可以只是在普通的地方不同，因为它是pcompiled，而不是即时编译$ P $。抖动可以做的更好，因为它有知识不可锋线。
Beware that the ngen-ed image contains machine code that was optimized by the jitter. That optimizer alters the machine code a great deal. Optimization is off by default in the debugger. To see it, you have to debug the Release build and change a debugger option. Tools + Options, Debugging, General, untick the "Suppress JIT optimization on module load" option. Also beware that the generated code can be just plain different in places because it was precompiled instead of jitted. The jitter can do a better job because it has knowledge that isn't available up front.
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