You have to know how .Net code "managed"?
Basically, all managed code directives are translated into IL directives, all IL directives are translated into assembly directives. The path is:
C# code/Vb.Net code/other .Net code ====> IL directive ==JIT==> assembly directive (machine code)
Take the method
System.Linq.Expressions.ExpressionCompiler.CompileDynamicLambda(...)
for example.
IL code dumpped by IL DASM
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
.method private hidebysig instance class [mscorlib]System.Delegate
CompileDynamicLambda(class System.Linq.Expressions.LambdaExpression lambda) cil managed
{
// Code size 87 (0x57)
.maxstack 5
.locals init (class System.Linq.Expressions.ExpressionCompiler/LambdaInfo V_0,
class System.Runtime.CompilerServices.ExecutionScope V_1,
int32 V_2)
IL_0000: ldarg.0
IL_0001: newobj instance void class [mscorlib]System.Collections.Generic.List`1<class System.Linq.Expressions.ExpressionCompiler/LambdaInfo>::.ctor()
IL_0006: stfld class [mscorlib]System.Collections.Generic.List`1<class System.Linq.Expressions.ExpressionCompiler/LambdaInfo> System.Linq.Expressions.ExpressionCompiler::lambdas
IL_000b: ldarg.0
IL_000c: newobj instance void class [mscorlib]System.Collections.Generic.List`1<object>::.ctor()
IL_0011: stfld class [mscorlib]System.Collections.Generic.List`1<object> System.Linq.Expressions.ExpressionCompiler::globals
IL_0016: ldarg.0
IL_0017: ldarg.1
IL_0018: call instance int32 System.Linq.Expressions.ExpressionCompiler::GenerateLambda(class System.Linq.Expressions.LambdaExpression)
IL_001d: stloc.2
IL_001e: ldarg.0
IL_001f: ldfld class [mscorlib]System.Collections.Generic.List`1<class System.Linq.Expressions.ExpressionCompiler/LambdaInfo> System.Linq.Expressions.ExpressionCompiler::lambdas
IL_0024: ldloc.2
IL_0025: callvirt instance !0 class [mscorlib]System.Collections.Generic.List`1<class System.Linq.Expressions.ExpressionCompiler/LambdaInfo>::get_Item(int32)
IL_002a: stloc.0
IL_002b: ldnull
IL_002c: ldloc.0
IL_002d: ldarg.0
IL_002e: ldfld class [mscorlib]System.Collections.Generic.List`1<object> System.Linq.Expressions.ExpressionCompiler::globals
IL_0033: callvirt instance !0[] class [mscorlib]System.Collections.Generic.List`1<object>::ToArray()
IL_0038: ldnull
IL_0039: newobj instance void System.Runtime.CompilerServices.ExecutionScope::.ctor(class System.Runtime.CompilerServices.ExecutionScope,
class System.Linq.Expressions.ExpressionCompiler/LambdaInfo,
object[],
object[])
IL_003e: stloc.1
IL_003f: ldloc.0
IL_0040: ldfld class [mscorlib]System.Reflection.MethodInfo System.Linq.Expressions.ExpressionCompiler/LambdaInfo::Method
IL_0045: castclass [mscorlib]System.Reflection.Emit.DynamicMethod
IL_004a: ldarg.1
IL_004b: callvirt instance class [mscorlib]System.Type System.Linq.Expressions.Expression::get_Type()
IL_0050: ldloc.1
IL_0051: callvirt instance class [mscorlib]System.Delegate [mscorlib]System.Reflection.Emit.DynamicMethod::CreateDelegate(class [mscorlib]System.Type,
object)
IL_0056: ret
} // end of method ExpressionCompiler::CompileDynamicLambda
CompileDynamicLambda(class System.Linq.Expressions.LambdaExpression lambda) cil managed
{
// Code size 87 (0x57)
.maxstack 5
.locals init (class System.Linq.Expressions.ExpressionCompiler/LambdaInfo V_0,
class System.Runtime.CompilerServices.ExecutionScope V_1,
int32 V_2)
IL_0000: ldarg.0
IL_0001: newobj instance void class [mscorlib]System.Collections.Generic.List`1<class System.Linq.Expressions.ExpressionCompiler/LambdaInfo>::.ctor()
IL_0006: stfld class [mscorlib]System.Collections.Generic.List`1<class System.Linq.Expressions.ExpressionCompiler/LambdaInfo> System.Linq.Expressions.ExpressionCompiler::lambdas
IL_000b: ldarg.0
IL_000c: newobj instance void class [mscorlib]System.Collections.Generic.List`1<object>::.ctor()
IL_0011: stfld class [mscorlib]System.Collections.Generic.List`1<object> System.Linq.Expressions.ExpressionCompiler::globals
IL_0016: ldarg.0
IL_0017: ldarg.1
IL_0018: call instance int32 System.Linq.Expressions.ExpressionCompiler::GenerateLambda(class System.Linq.Expressions.LambdaExpression)
IL_001d: stloc.2
IL_001e: ldarg.0
IL_001f: ldfld class [mscorlib]System.Collections.Generic.List`1<class System.Linq.Expressions.ExpressionCompiler/LambdaInfo> System.Linq.Expressions.ExpressionCompiler::lambdas
IL_0024: ldloc.2
IL_0025: callvirt instance !0 class [mscorlib]System.Collections.Generic.List`1<class System.Linq.Expressions.ExpressionCompiler/LambdaInfo>::get_Item(int32)
IL_002a: stloc.0
IL_002b: ldnull
IL_002c: ldloc.0
IL_002d: ldarg.0
IL_002e: ldfld class [mscorlib]System.Collections.Generic.List`1<object> System.Linq.Expressions.ExpressionCompiler::globals
IL_0033: callvirt instance !0[] class [mscorlib]System.Collections.Generic.List`1<object>::ToArray()
IL_0038: ldnull
IL_0039: newobj instance void System.Runtime.CompilerServices.ExecutionScope::.ctor(class System.Runtime.CompilerServices.ExecutionScope,
class System.Linq.Expressions.ExpressionCompiler/LambdaInfo,
object[],
object[])
IL_003e: stloc.1
IL_003f: ldloc.0
IL_0040: ldfld class [mscorlib]System.Reflection.MethodInfo System.Linq.Expressions.ExpressionCompiler/LambdaInfo::Method
IL_0045: castclass [mscorlib]System.Reflection.Emit.DynamicMethod
IL_004a: ldarg.1
IL_004b: callvirt instance class [mscorlib]System.Type System.Linq.Expressions.Expression::get_Type()
IL_0050: ldloc.1
IL_0051: callvirt instance class [mscorlib]System.Delegate [mscorlib]System.Reflection.Emit.DynamicMethod::CreateDelegate(class [mscorlib]System.Type,
object)
IL_0056: ret
} // end of method ExpressionCompiler::CompileDynamicLambda
assembly code dumped by SOS in runtime
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
!u 6c20cef0
preJIT generated code
System.Linq.Expressions.ExpressionCompiler.CompileDynamicLambda(System.Linq.Expressions.LambdaExpression)
Begin 6c318010, size c7
6C318010 55 push ebp
6C318011 8BEC mov ebp,esp
6C318013 57 push edi
6C318014 56 push esi
6C318015 53 push ebx
6C318016 50 push eax
6C318017 8BF9 mov edi,ecx
6C318019 8BDA mov ebx,edx
6C31801B B9B0A4376C mov ecx,6C37A4B0h (MT: System.Collections.Generic.List`1[[System.Linq.Expressions.ExpressionCompiler+LambdaInfo, System.Core]])
6C318020 E853EFF1FF call 6C236F78
6C318025 8BF0 mov esi,eax
6C318027 8BCE mov ecx,esi
6C318029 E8D2D1F1FF call 6C235200 (System.Collections.Generic.List`1[[System.__Canon, mscorlib]]..ctor(), mdToken: 060019e0)
6C31802E 8D5704 lea edx,[edi+4]
6C318031 E8BAEFF1FF call 6C236FF0
6C318036 8B0DF4E01D6C mov ecx,dword ptr ds:[6C1DE0F4h] (MT: System.Collections.Generic.List`1[[System.Object, mscorlib]])
6C31803C E837EFF1FF call 6C236F78
6C318041 8BF0 mov esi,eax
6C318043 8BCE mov ecx,esi
6C318045 E8B6D1F1FF call 6C235200 (System.Collections.Generic.List`1[[System.__Canon, mscorlib]]..ctor(), mdToken: 060019e0)
6C31804A 8D5708 lea edx,[edi+8]
6C31804D E89EEFF1FF call 6C236FF0
6C318052 8BD3 mov edx,ebx
6C318054 8BCF mov ecx,edi
6C318056 E8CD7AF2FF call 6C23FB28 (System.Linq.Expressions.ExpressionCompiler.GenerateLambda(System.Linq.Expressions.LambdaExpression), mdToken: 06000374)
6C31805B 8B4F04 mov ecx,dword ptr [edi+4]
6C31805E 8BD0 mov edx,eax
6C318060 3909 cmp dword ptr [ecx],ecx
6C318062 E8D9D3F1FF call 6C235440 (System.Collections.Generic.List`1[[System.__Canon, mscorlib]].get_Item(Int32), mdToken: 060019eb)
6C318067 8945F0 mov dword ptr [ebp-10h],eax
6C31806A B9ACAD386C mov ecx,6C38ADACh (MT: System.Runtime.CompilerServices.ExecutionScope)
6C31806F E804EFF1FF call 6C236F78
6C318074 8BF0 mov esi,eax
6C318076 8B4F08 mov ecx,dword ptr [edi+8]
6C318079 3909 cmp dword ptr [ecx],ecx
6C31807B E830D2F1FF call 6C2352B0 (System.Collections.Generic.List`1[[System.__Canon, mscorlib]].ToArray(), mdToken: 06001a25)
6C318080 8BC8 mov ecx,eax
6C318082 33D2 xor edx,edx
6C318084 895604 mov dword ptr [esi+4],edx
6C318087 8B45F0 mov eax,dword ptr [ebp-10h]
6C31808A 8D5610 lea edx,[esi+10h]
6C31808D E8CEEEF1FF call 6C236F60
6C318092 8D5608 lea edx,[esi+8]
6C318095 E8AEEFF1FF call 6C237048
6C31809A 33D2 xor edx,edx
6C31809C 89560C mov dword ptr [esi+0Ch],edx
6C31809F 8B45F0 mov eax,dword ptr [ebp-10h]
6C3180A2 8B780C mov edi,dword ptr [eax+0Ch]
6C3180A5 85FF test edi,edi
6C3180A7 741B je 6C3180C4
6C3180A9 8B07 mov eax,dword ptr [edi]
6C3180AB 3B057CE11D6C cmp eax,dword ptr ds:[6C1DE17Ch]
6C3180B1 7502 jne 6C3180B5
6C3180B3 EB0F jmp 6C3180C4
6C3180B5 8B0D7CE11D6C mov ecx,dword ptr ds:[6C1DE17Ch] (MT: System.Reflection.Emit.DynamicMethod)
6C3180BB 8BD7 mov edx,edi
6C3180BD E83EEFF1FF call 6C237000
6C3180C2 8BF8 mov edi,eax
6C3180C4 8BCF mov ecx,edi
6C3180C6 8B5304 mov edx,dword ptr [ebx+4]
6C3180C9 56 push esi
6C3180CA 3909 cmp dword ptr [ecx],ecx
6C3180CC E877D3F1FF call 6C235448 (System.Reflection.Emit.DynamicMethod.CreateDelegate(System.Type, System.Object), mdToken: 06004946)
6C3180D1 59 pop ecx
6C3180D2 5B pop ebx
6C3180D3 5E pop esi
6C3180D4 5F pop edi
6C3180D5 5D pop ebp
6C3180D6 C3 ret
preJIT generated code
System.Linq.Expressions.ExpressionCompiler.CompileDynamicLambda(System.Linq.Expressions.LambdaExpression)
Begin 6c318010, size c7
6C318010 55 push ebp
6C318011 8BEC mov ebp,esp
6C318013 57 push edi
6C318014 56 push esi
6C318015 53 push ebx
6C318016 50 push eax
6C318017 8BF9 mov edi,ecx
6C318019 8BDA mov ebx,edx
6C31801B B9B0A4376C mov ecx,6C37A4B0h (MT: System.Collections.Generic.List`1[[System.Linq.Expressions.ExpressionCompiler+LambdaInfo, System.Core]])
6C318020 E853EFF1FF call 6C236F78
6C318025 8BF0 mov esi,eax
6C318027 8BCE mov ecx,esi
6C318029 E8D2D1F1FF call 6C235200 (System.Collections.Generic.List`1[[System.__Canon, mscorlib]]..ctor(), mdToken: 060019e0)
6C31802E 8D5704 lea edx,[edi+4]
6C318031 E8BAEFF1FF call 6C236FF0
6C318036 8B0DF4E01D6C mov ecx,dword ptr ds:[6C1DE0F4h] (MT: System.Collections.Generic.List`1[[System.Object, mscorlib]])
6C31803C E837EFF1FF call 6C236F78
6C318041 8BF0 mov esi,eax
6C318043 8BCE mov ecx,esi
6C318045 E8B6D1F1FF call 6C235200 (System.Collections.Generic.List`1[[System.__Canon, mscorlib]]..ctor(), mdToken: 060019e0)
6C31804A 8D5708 lea edx,[edi+8]
6C31804D E89EEFF1FF call 6C236FF0
6C318052 8BD3 mov edx,ebx
6C318054 8BCF mov ecx,edi
6C318056 E8CD7AF2FF call 6C23FB28 (System.Linq.Expressions.ExpressionCompiler.GenerateLambda(System.Linq.Expressions.LambdaExpression), mdToken: 06000374)
6C31805B 8B4F04 mov ecx,dword ptr [edi+4]
6C31805E 8BD0 mov edx,eax
6C318060 3909 cmp dword ptr [ecx],ecx
6C318062 E8D9D3F1FF call 6C235440 (System.Collections.Generic.List`1[[System.__Canon, mscorlib]].get_Item(Int32), mdToken: 060019eb)
6C318067 8945F0 mov dword ptr [ebp-10h],eax
6C31806A B9ACAD386C mov ecx,6C38ADACh (MT: System.Runtime.CompilerServices.ExecutionScope)
6C31806F E804EFF1FF call 6C236F78
6C318074 8BF0 mov esi,eax
6C318076 8B4F08 mov ecx,dword ptr [edi+8]
6C318079 3909 cmp dword ptr [ecx],ecx
6C31807B E830D2F1FF call 6C2352B0 (System.Collections.Generic.List`1[[System.__Canon, mscorlib]].ToArray(), mdToken: 06001a25)
6C318080 8BC8 mov ecx,eax
6C318082 33D2 xor edx,edx
6C318084 895604 mov dword ptr [esi+4],edx
6C318087 8B45F0 mov eax,dword ptr [ebp-10h]
6C31808A 8D5610 lea edx,[esi+10h]
6C31808D E8CEEEF1FF call 6C236F60
6C318092 8D5608 lea edx,[esi+8]
6C318095 E8AEEFF1FF call 6C237048
6C31809A 33D2 xor edx,edx
6C31809C 89560C mov dword ptr [esi+0Ch],edx
6C31809F 8B45F0 mov eax,dword ptr [ebp-10h]
6C3180A2 8B780C mov edi,dword ptr [eax+0Ch]
6C3180A5 85FF test edi,edi
6C3180A7 741B je 6C3180C4
6C3180A9 8B07 mov eax,dword ptr [edi]
6C3180AB 3B057CE11D6C cmp eax,dword ptr ds:[6C1DE17Ch]
6C3180B1 7502 jne 6C3180B5
6C3180B3 EB0F jmp 6C3180C4
6C3180B5 8B0D7CE11D6C mov ecx,dword ptr ds:[6C1DE17Ch] (MT: System.Reflection.Emit.DynamicMethod)
6C3180BB 8BD7 mov edx,edi
6C3180BD E83EEFF1FF call 6C237000
6C3180C2 8BF8 mov edi,eax
6C3180C4 8BCF mov ecx,edi
6C3180C6 8B5304 mov edx,dword ptr [ebx+4]
6C3180C9 56 push esi
6C3180CA 3909 cmp dword ptr [ecx],ecx
6C3180CC E877D3F1FF call 6C235448 (System.Reflection.Emit.DynamicMethod.CreateDelegate(System.Type, System.Object), mdToken: 06004946)
6C3180D1 59 pop ecx
6C3180D2 5B pop ebx
6C3180D3 5E pop esi
6C3180D4 5F pop edi
6C3180D5 5D pop ebp
6C3180D6 C3 ret