Making archive IL2C #6-55 dotNET600 2018

発表時点のIL2Cの中心技術の解説を行ったスライドです。

IL2Cは、.NETのアセンブリをC言語のコードに変換するツールセットです。
ビデオ録画も参照して下さい:
YouTube: https://www.youtube.com/watch?v=Y--YjQQLdcg

What’s the IL2C​
* Building scheme​

Translation details​
* The runtime types – primitive and string​
* How works the garbage collector​
* The value type / boxing​
* The enum types​
* The delegate types​
* How works exceptions​
* How works virtual methods (virtual, override and interface implementations)​

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.NET Conf 2019 meetup in AICHI
https://centerclr.connpass.com/event/143949

Transcript

1. Making archive
   IL2C
   #6-55
   2018.11.24 DOTNET600 2018
   - KOUJI MATSUI (@KOZY_KEKYO, @KEKYO2)
   

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2. Kouji Matsui – kozy, kekyo
   • NAGOYA city, AICHI pref., JP
   • Twitter – @kozy_kekyo, @kekyo2 /
   Facebook
   • Self employed (I’m looking for a job)
   • Microsoft Most Valuable Professional VS
   and DevTech 2015-
   • Certified Scrum master / Scrum product
   owner
   • Center CLR organizer.
   • .NET/C#/F#/IL/metaprogramming or like…
   • Bike rider
   

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3. Agenda
   Abstract
   What’s the IL2C
   ◦ Building scheme
   Translation details
   ◦ The runtime types – primitive and string
   ◦ How works the garbage collector
   ◦ The value type / boxing
   ◦ The enum types
   ◦ The delegate types
   ◦ How works exceptions
   ◦ How works virtual methods (virtual, override and interface implementations)
   

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4. Abstract
   WARNING:
   ◦ This session contains very complex technology topics reached for LEVEL 600
   or above.
   ◦ Are you ready? ;)
   How works and aiming for tiny resource requirements by the IL2C?
   How works AOT (ahead of time compilation) by the IL2C?
   What’s done, doing and will do the IL2C project?
   

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5. Agenda
   Abstract
   What’s the IL2C
   ◦ Building scheme
   Translation details
   ◦ The runtime types – primitive and string
   ◦ How works the garbage collector
   ◦ The value type / boxing
   ◦ The enum types
   ◦ The delegate types
   ◦ How works exceptions
   ◦ How works virtual methods (virtual, override and interface implementations)
   

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6. What’s the IL2C
   A translator for
   ECMA-335 CIL/MSIL to C language.
   F# Code
   IL2C
   Target native
   binary
   C# Code
   

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7. What’s the IL2C
   https://github.com/kekyo/IL2C
   

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8. What’s the IL2C
   IL2C's implementation priorities, we're aiming for:
   ◦ Better predictability for runtime costs, better human readability for the IL2C
   translated C source code.
   ◦ Very tiny footprint requirements, we are thinking about how fit between tiny
   embedded system and large system with many resources.
   ◦ Better code/runtime portability, minimum requirements are only C99
   compiler.
   ◦ Better interoperabilities for exist C libraries, we can use standard .NET interop
   technics (likely P/Invoke.)
   ◦ Contains seamless building system for major C toolkits, for example: CMake
   system, Arduino IDE, VC++ ...
   

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9. What’s the IL2C
   IL2C
   Assembly
   (*.dll)
   C Language
   (*.c, *.h)
   C Language
   (*.c, *.h)
   Target dev C language compiler
   (VS, Arduino, mbed and etc…)
   Target native
   binary
   C# Code C# Compiler
   (Roslyn)
   F# Compiler
   (FCS)
   F# Code
   Another compiler
   

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10. C language source code
    CIL / MSIL ECMA-335 specific binaries
    What’s the IL2C
    IL2C
    Assembly
    (*.dll)
    C Language
    (*.c, *.h)
    C Language
    (*.c, *.h)
    Target dev C language compiler
    (VS, Arduino, mbed and etc…)
    Target native
    binary
    C# Code C# Compiler
    (Roslyn)
    F# Compiler
    (FCS)
    F# Code
    

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11. Building schemes (aiming for)
    IL2C
    Assembly
    (*.dll)
    C Language
    (*.c, *.h)
    C Language
    (*.c, *.h)
    Target dev C language compiler
    (VS, Arduino, mbed and etc…)
    Target native
    binary
    C# Code
    C# Compiler
    (Roslyn)
    NuGet
    (*.dll)
    C Language
    (*.c, *.h)
    IL2C Runtime
    (*.c, *.h)
    Prebuilt
    Libraries
    3rd party
    Libraries
    

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12. Agenda
    Abstract
    What’s the IL2C
    ◦ Building scheme
    Translation details
    ◦ The runtime types – primitive and string
    ◦ How works the garbage collector
    ◦ The value type / boxing
    ◦ The enum types
    ◦ The delegate types
    ◦ How works exceptions
    ◦ How works virtual methods (virtual, override and interface implementations)
    

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13. The runtime types – primitive and string
    typedef aliases
    ◦ stdint.h, stdbool.h, wchar_t, float.h
    byte short int long sbyte ushort uint ulong
    uint8_t int16_t int32_t int64_t int8_t uint16_t uint32_t uint64_t
    float double bool char IntPtr UIntPtr
    float double bool wchar_t intptr_t uintptr_t
    

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14. The runtime types – primitive and string
    System.String – variable strage space
    System_String_VTable
    System_String (heap)
    vptr0__
    string_body__
    “ABCDEFGHIJ\0”
    

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15. The runtime types – primitive and string
    Constant literal string
    System_String_VTABLE
    System_String (.rdata)
    vptr0__
    string_body__
    const wchar_t[] (.rdata)
    “ABCDEFGHIJ\0”
    

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16. IL2C_REF_HEADER (.rdata)
    The runtime types – primitive and string
    Constant literal string
    System_String
    vptr0__
    string_body__
    const wchar_t[] (.rdata)
    “ABCDEFGHIJ\0”
    pNext
    type
    gcMark
    VTABLE
    

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17. Agenda
    Abstract
    What’s the IL2C
    ◦ Building scheme
    Translation details
    ◦ The runtime types – primitive and string
    ◦ How works the garbage collector
    ◦ The value type / boxing
    ◦ The enum types
    ◦ The delegate types
    ◦ How works exceptions
    ◦ How works virtual methods (virtual, override and interface implementations)
    

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18. How works the garbage collector
    Basic strategy – mark and sweep algorithm (NOT include compaction)
    Root Root Root
    1. Clear mark
    2. Set mark 3. Free unmarked
    

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19. How works the garbage collector: Phase 1
    IL2C_REF_HEADER (heap)
    pNext
    type
    gcMark
    IL2C_REF_HEADER (heap)
    pNext
    g_pBeginHeader
    GCMARK_NOMARK
    GCMARK_NOMARK
    

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20. How works the garbage collector: Phase 2
    IL2C_REF_HEADER (heap)
    pNext
    type
    gcMark
    g_pBeginFrame
    GCMARK_LIVE
    GCMARK_LIVE
    GCMARK_LIVE
    System_String
    vptr0__
    string_body__
    “ABCDEFGHIJ\0”
    

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21. How works the garbage collector: Phase 2
    Function1()
    Function2()
    Function3()
    local1
    local2
    local1
    local2
    local3
    g_pBeginFrame
    local2
    GCMARK_LIVE
    null
    null
    null
    Step2 details
    local1 null
    2
    

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22. How works the garbage collector: Phase 3
    IL2C_REF_HEADER (heap)
    pNext
    type
    gcMark
    IL2C_REF_HEADER (heap)
    pNext
    g_pBeginHeader
    GCMARK_LIVE
    GCMARK_NOMARK
    GCMARK_NOMARK
    GCMARK_NOMARK
    GCMARK_LIVE
    

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23. Agenda
    Abstract
    What’s the IL2C
    ◦ Building scheme
    Translation details
    ◦ The runtime types – primitive and string
    ◦ How works the garbage collector
    ◦ The value type / boxing
    ◦ The enum types
    ◦ The delegate types
    ◦ How works exceptions
    ◦ How works virtual methods (virtual, override and interface implementations)
    

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24. IL2C_REF_HEADER (heap)
    System_ValueType
    The value type / boxing
    pNext
    type
    gcMark
    vptr0__
    System_Int32
    System_Int32 Boxed
    32bit (4bytes)
    Bit exactly
    sizeof(IL2C_REF_HEADER) +
    sizeof(System_ValueType) +
    sizeof(System_Int32)
    

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25. IL2C_REF_HEADER (heap)
    System_ValueType
    The value type / boxing
    pNext
    type
    gcMark
    vptr0__
    System_Int32 Unboxed (System_Int32*)
    System_Int32 local
    1. Got pointer
    2. Dereference
    (Copy)
    

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26. The value type / boxing
    Unboxed and NOT copy…
    Copy-free
    

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27. The value type / boxing
    Valid?
    Q1:
    

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28. The value type / boxing
    Valid?
    The value type is restricted for marking
    “virtual” by Roslyn.
    Therefore we can force virtualize by
    assigning the interface.
    Will boxed for call
    Q2:
    

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29. The value type / boxing
    Valid?
    Mutable usage by the
    virtual method
    …Boxed?
    Q3:
    

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30. The value type / boxing : Q1
    System_Int32 (System_Int32*)
    System_Int32_ToString(
    System_Int32* this)
    1. Got pointer
    2. Arg0 (this)
    Copy-free invoking
    

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31. IL2C_REF_HEADER (heap)
    System_ValueType
    The value type / boxing : Q3
    pNext
    type
    gcMark
    vptr0__
    System_Int32
    System_Int32_VTABLE (.rdata)
    offset__
    System_Int32_Equals(…)
    System_Object_Finalize(…)
    System_Int32_GetHashCode(…)
    System_Int32_ToString(…)
    System_Int32_ToString(
    System_Int32* this)
    Where’s unboxing?
    

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32. The value type / boxing : Q3
    System_Int32_VTABLE (.rdata)
    offset__
    System_Int32_Equals_VFunc(…)
    System_Object_Finalize(…)
    System_Int32_GetHashCode_VFunc(…)
    System_Int32_ToString_VFunc(…)
    System_Int32_ToString_VFunc(
    System_ValueType* this)
    System_Int32_ToString(
    System_Int32* this)
    Unboxing
    (And not copy)
    We can (have to) manipulate
    the instance fields
    

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33. The value type / boxing : Q2
    System_Int32_IFoo_VTABLE (.rdata)
    offset__
    System_Int32_ToString_VFunc(…)
    System_Int32_ToString_VFunc(
    System_ValueType* this)
    System_Int32_ToString(
    System_Int32* this)
    Unboxing
    (And not copy)
    We can manipulate the instance
    fields, but gonna discard
    

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34. The value type / boxing
    My strategy was:
    ◦ Q1: The value type methods can access their fields by using unboxed-raw-
    pointer. (Copy-free access)
    →
    ◦ Q2: The interface implementation way can same procedure
    → We have to copy the instance…
    ◦ Q3: The value type virtual methods same procedure…
    →
    Will fix this problem…
    

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35. Agenda
    Abstract
    What’s the IL2C
    ◦ Building scheme
    Translation details
    ◦ The runtime types – primitive and string
    ◦ How works the garbage collector
    ◦ The value type / boxing
    ◦ The enum types
    ◦ The delegate types
    ◦ How works exceptions
    ◦ How works virtual methods (virtual, override and interface implementations)
    

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36. The enum types
    Q: How implement the enum types will you use the C language?
    translate
    C# (IL) C
    

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37. The enum types
    Q: How implement the enum types will you use the C language?
    translate
    C# (IL) C
    It has 2 problems
    

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38. The enum types
    A1: The enum symbol names are globally. We have to able to apply
    different names each enum types…
    C
    Combined namespace
    Combined namespace and
    each value symbol
    

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39. The enum types
    A2: In the C language, enum types can’t annotate the storage space.
    C
    consoleapplication1.c(3):
    error C2059: syntax error: ':'
    In the C++, we can
    use this syntax
    

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40. The enum types
    Final results for IL2C way:
    C
    The IL2C has to calculate real
    value at each symbols…
    

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41. The enum types
    Final results for IL2C way:
    ◦ Each enum types NOT derived from System.Enumtype.
    ◦ We can implicitly convert by bidirection both enum types and integer types.
    Convert from Int32 to
    Int32EnumType implicitly.
    C#
    IL
    

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42. The enum types
    Convert from Int32 to
    Int32EnumType implicitly.
    C
    

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43. Agenda
    Abstract
    What’s the IL2C
    ◦ Building scheme
    Translation details
    ◦ The runtime types – primitive and string
    ◦ How works the garbage collector
    ◦ The value type / boxing
    ◦ The enum types
    ◦ The delegate types
    ◦ How works exceptions
    ◦ How works virtual methods (virtual, override and interface implementations)
    

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44. The delegate types
    The delegate types almost always inherited from System.MulticastDelegate.
    ◦ System.Delegate type has two member for “Method” and “Target.”
    ◦ The derived delegate type has the type-safe method named “Invoke.”
    System.Object
    System.Delegate
    System.MulticastDelegate
    System.EventHandler
    void Invoke(
    object sender, EventArgs e)
    MethodInfo Method;
    object Target;
    

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45. The delegate types
    “Method” member is the information for callee.
    ◦ If callee method is static (not instance method), the “Target” is null.
    private static void Form_Clicked(
    object sender, EventArgs e)
    static method
    callee method
    System.Delegate
    Target
    Method
    Target (instance)
    is nothing
    null
    

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46. class Bar.Form
    The delegate types
    ◦ If callee method is instance (not static method), the “Target” refer to instance.
    System.Delegate private void Form_Clicked(
    object sender, EventArgs e)
    Target
    Method
    instance method
    Target (instance)
    callee method
    

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47. The delegate types
    The IL2C way puts the code with instance detection expression.
    System_EventHandler_Invoke(…)
    C
    C#
    Detect the “Target” is not NULL
    

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48. The delegate types
    The instance method into value type can assign to delegate and valid.
    Refer to:
    public override string System.Int32.ToString()
    C#
    

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49. The delegate types
    The instance method into value type can assign to delegate and valid.
    boxing
    Resolve for
    virtual method pointer
    IL
    

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50. IL2C_REF_HEADER (heap)
    The delegate types
    The boxing opcode is very important in this case. Because the “Target”
    member type is System.Object, so can’t store the native value or
    managed pointer.
    value type System.Int32
    System.Delegate
    public override string ToString()
    Target (System.Object)
    Method
    instance method
    Target (boxed)
    

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51. The delegate types
    Illustrates, the System.MulticastDelegate can hold multiple delegates
    into the delegate. The implementation is the list of delegates.
    It contains delegate[]
    C#
    

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52. The delegate types
    Illustrates, the System.MulticastDelegate can contain multiple delegates
    into one delegate. The implementation is the list of delegates.
    MulticastDelegate
    invocationList
    …
    delegate[]
    [0]
    [1]
    [2]
    …
    System.Delegate
    …
    System.Delegate
    …
    System.Delegate
    …
    

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53. IL2C_REF_HEADER (heap)
    IL2C_REF_HEADER (heap)
    IL2C_REF_HEADER (heap)
    IL2C_REF_HEADER
    IL2C_REF_HEADER (heap)
    The delegate types
    We know, these instances came from the heap…
    MulticastDelegate
    invocationList
    …
    delegate[]
    [0]
    [1]
    [2]
    …
    System.Delegate
    …
    System.Delegate
    …
    System.Delegate
    …
    Too many allocation!!
    

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54. The delegate types
    The IL2C way, all delegate types aggregate into the one implement at
    “System_Delegate.” It contains list of delegate and it’s NON-array. Most
    important thing is the delegate storage size is VARIABLE.
    System_Delegate
    …
    …
    [0] Target
    [0] Method
    [1] Target
    [1] Method
    private static void Form_Clicked(
    object sender, EventArgs e)
    private static void Form_Clicked(
    object sender, EventArgs e)
    Variable
    Invocation table
    

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55. IL2C_REF_HEADER (heap)
    The delegate types
    It will reduce heap management cost
    System_Delegate
    …
    …
    [0] Target
    [0] Method
    [1] Target
    [1] Method
    private static void Form_Clicked(
    object sender, EventArgs e)
    private static void Form_Clicked(
    object sender, EventArgs e)
    

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56. The delegate types
    The IL2C’s System_Delegate real declaration:
    Target instance (or null)
    Function pointer
    Invocation list
    

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57. The delegate types
    Delegate.Combine() and Delegate.Remove() calculate and store invocation
    table only once allocated delegate instance.
    C
    Allocate once
    Delegate.Combine(…)
    Combine the invocation tables
    

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58. The delegate types
    Overall the IL2C translate to the specialized delegate invoker:
    C
    Invocation table
    Invoke by function pointer
    For all method
    

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59. Agenda
    Abstract
    What’s the IL2C
    ◦ Building scheme
    Translation details
    ◦ The runtime types – primitive and string
    ◦ How works the garbage collector
    ◦ The value type / boxing
    ◦ The enum types
    ◦ The delegate types
    ◦ How works exceptions
    ◦ How works virtual methods (virtual, override and interface implementations)
    

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60. How works exceptions
    What’s the “local unwind?”
    C#
    

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61. How works exceptions
    What’s the “local unwind?”
    C#
    Only inside for the method
    

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62. How works exceptions
    What’s the “global unwind?”
    C#
    

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63. How works exceptions
    What’s the “global unwind?”
    C#
    It’s transition by straddling
    

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64. How works exceptions
    Important global unwind things:
    ◦ We have to find the matched exception filter (“catch” type clause.)
    ◦ If not found, try to find more filters crawling from stack frame top to bottom.
    Illustrated:
    Function1()
    Function2()
    Function3()
    Function4()
    C
    Function5()
    null
    main()
    Stack frame top
    Stack frame bottom
    g_pBeginFrame
    

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65. How works exceptions
    Does the method contains multiple exception blocks?
    C#
    

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66. How works exceptions
    Does the method contains multiple exception blocks?
    C#
    Ignored the exception filter
    

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67. How works exceptions
    The unwind feature is likely stack crawling on the stack frame, but
    we have to complete exception handling with bit different:
    ◦ We have to use the “Exception frame.” instead the stack frame.
    ◦ It’s only instantiate for each exception blocks.
    Exception block 2
    RaiseNestedBlockLocal()
    null
    main()
    Exception block 1
    Exception frame 1
    Exception frame 2
    g_pTopUnwindTarget
    

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68. How works exceptions
    How works the exception frames on the global unwind?
    RaiseNestedBlockGlobal()
    null
    main()
    Exception frame 1
    g_pTopUnwindTarget
    RaiseNestedBlockCallee()
    Exception frame 2
    Exception block 1
    Exception block 2
    

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69. How works exceptions
    This is the exception frame and overall usage.
    C
    Function3()
    Exception frame 3
    g_pTopUnwindTarget
    Function1()
    null
    main()
    Exception frame 1
    Exception frame 2
    Function2()
    This function doesn’t
    contain any exception
    block
    

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70. How works exceptions
    The IL2C handles exception by the way:
    1. Raise exception with strongly-typed instance.
    2. The runtime crawl the exception frames from “Top exception frame” to
    bottom. The “g_pTopUnwindFrame” pointer refers top frame.
    3. Call the exception filter function from each exception frames.
    4. If found the exception type from exception filter function, IL2C found
    catchable block. Send the execution context into it (unwind done).
    5. If can’t find any cachable block at the bottom frame, the IL2C raise
    “Unhandled exception” state.
    

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71. How works exceptions
    What’s the exception filter?
    C
    int16_t Function1_ExceptionFilter_0(
    System_Exception* ex)
    

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72. How works exceptions
    What’s the exception filter?
    C
    Index number for local
    exception frame
    Method name
    “catch (Exception)”
    Result is filter number
    (unique in each filter)
    

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73. How works exceptions
    If a exception block contain multiple caught blocks?
    C#
    Contains multiple caught
    into one exception block
    

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74. How works exceptions
    If a exception block contain multiple caught blocks?
    C
    Result is filter number
    Series checks exception type
    

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75. How works exceptions
    The “Filter number” is used for branching identity at the method
    body. Illustrated bone of the exception block:
    C
    Use this filter function
    The filter number
    

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76. How works exceptions
    “il2c_try”
    “il2c_catch”
    “il2c_end_try” and another exception handling helpers:
    Declared by C language macro. How works these macros details??
    

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77. How works exceptions
    C
    Exception frame
    declared each try block
    branch using setjmp() result
    to try and catch block
    Saved current
    execution context
    

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78. How works exceptions
    C
    Use longjmp() function. The execution
    context will unwind to “saved.”
    How the exception raising side?
    

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79. How works exceptions
    A lot… a lot of topics for the exception handling, this session
    uncovererd:
    ◦ How works “rethrow” feature?
    ◦ How works nested rethrow feature?
    ◦ How works nested local exception block?
    ◦ How works finally block?
    ◦ How works filter-fault blocks?
    ◦ The setjmp and longjmp way (named sjlj) is slower. Can we improve by another
    way?
    ◦ How works asynchronous exception? (NullReferenceException,
    ArithmeticExceptionand etc…)
    

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80. Agenda
    Abstract
    What’s the IL2C
    ◦ Building scheme
    Translation details
    ◦ The runtime types – primitive and string
    ◦ How works the garbage collector
    ◦ The value type / boxing
    ◦ The enum types
    ◦ The delegate types
    ◦ How works exceptions
    ◦ How works virtual methods (virtual, override and interface implementations)
    

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81. How works virtual methods
    The runtime type information:
    IL2C_REF_HEADER (heap)
    pNext
    type
    gcMark
    System_String
    vptr0__
    string_body__
    “ABCDEFGHIJ\0”
    IL2C_RUNTIME_TYPE_DECL (.rdata)
    pTypeName
    flags
    bodySize
    baseType
    vptr0
    markTarget
    interfaceCount
    …
    “System.String”
    (UTF8 string)
    [System.Object]
    IL2C_RUNTIME_TYPE_DECL
    Copy
    …
    System_String_VTABLE__
    …
    

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82. How works virtual methods
    C
    IL2C_TYPE_REFERENCE (objref)
    IL2C_TYPE_VALUE (value type)
    IL2C_TYPE_VARIABLE (variable storage size)
    …
    The C language not valid using for sizeof()
    expression via empty storage space type.
    So this field coverered size is 0.
    

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83. How works virtual methods
    The virtual method table (VTABLE) works:
    IL2C_RUNTIME_TYPE_DECL
    …
    vptr0
    …
    System_String
    vptr0__
    string_body__
    System_String_VTABLE (.rdata)
    offset__
    System_String_Equals(…)
    System_Object_Finalize(…)
    System_String_GetHashCode(…)
    System_String_ToString(…)
    System_String_GetHashCode(
    System_String* this)
    0
    

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84. How works virtual methods
    How works invoking virtual method?
    C#
    

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85. How works virtual methods
    How works invoking virtual method? C
    VirtualBaseType_VTABLE__
    offset__
    GetStringFromInt32(…)
    … VirtualBaseType_GetStringFromInt32(
    VirtualBaseType* this, int32_t value)
    0
    vptr0__
    

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86. How works virtual methods
    How works invoking virtual method? C
    VirtualBaseType_VTABLE__
    offset__
    GetStringFromInt32(…)
    …
    0
    VirtualBaseType_GetStringFromInt32(
    VirtualBaseType* this, int32_t value)
    Subtract offset from this pointer.
    But the “offset__” field always 0…
    arg0 = this - offset__
    

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87. How works virtual methods
    The interface virtual method table works:
    C#
    Interface implemented
    

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88. How works virtual methods
    The interface virtual method table works:
    TYPE [VirtualNewAndImplementType]
    …
    VirtualNewAndImplementType
    VirtualNewAndImplementType_VTABLE
    VirtualNewAndImplementType_GetStringFromInt32(
    VirtualNewAndImplementType* this)
    vptr0__
    vptr0__
    vptr_IInterfaceType1
    …
    …
    VirtualNewAndImplementType_IInterfaceType1_VTABLE
    offset__
    TYPE [IInterfaceType1]
    …
    interfaceType
    vptrInterface
    void GetStringFromInt32 ()
    offset__
    0
    4
    +0
    +4
    arg0 = this - offset__
    The interface VTABLE
    contains this pointer’s offset.
    Subtract offset to adjust
    pointer.
    

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89. How works virtual methods
    How works invoking interface virtual method? C
    VirtualNewImplements_IInterfaceType1_VTABLE
    offset__
    GetStringFromInt32(…)
    …
    4
    True same calculation both the class
    VTABLE and interface VTABLE.
    arg0 = this - offset__
    VirtualNewAndImplementType_GetStringFromInt32(
    VirtualNewAndImplementType* this)
    

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90. How works virtual methods
    C#
    Implicit implement
    

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91. How works virtual methods
    C#
    

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92. How works virtual methods C#
    1. Find the interface
    from mostly derived
    2. Listup methods from
    found to same signature
    3. Find the method from mostly
    overrided and NOT newslot
    

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93. Any question? Thank you for join!!
    https://github.com/kekyo/IL2C
    

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