社内版SwiftコンパイラにContributeするまで

Transcript

1. SwiftίϯύΠϥʹContribute͢Δ·Ͱ
   freddi (LINE Fukuoka)
   Engineer Casual Meetup - Oct. 9 2020
   

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2. Agenda
   • Contributeͨ͠಺༰ ͷ͸ͳ͠
   
   • Swift ͷίϯύΠϧϑϩʔ ͷ͸ͳ͠
   
   • Swift Intermediate Language ͷ͸ͳ͠
   
   • SILOptimizer ʹ͍ͭͯ
   
   • (͋ΒͨΊͯ) Contributeͨ͠಺༰ ͷ͸ͳ͠
   

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3. Agenda
   • Contributeͨ͠಺༰ ͷ͸ͳ͠
   
   • Swift ͷίϯύΠϧϑϩʔ ͷ͸ͳ͠
   
   • Swift Intermediate Language ͷ͸ͳ͠
   
   • SILOptimizer ʹ͍ͭͯ
   
   • (͋ΒͨΊͯ) Contributeͨ͠಺༰ ͷ͸ͳ͠
   ๻ͷೖ໳ϑϩʔ
   

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4. Contributeͨ͠಺༰ ͷ͸ͳ͠
   • ̎ͭ Contribute ͨ͠
   
   • https://github.com/apple/swift/pull/33851
   
   • ࠷దԽϩδοΫͷϛε
   
   • https://github.com/apple/swift/pull/31847
   
   • Docs ͷ BNF Ͱॻ͔Εͨ Grammer ͷϛε
   

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5. Contributeͨ͠಺༰ ͷ͸ͳ͠
   • https://github.com/apple/swift/pull/33851
   
   • ࠷దԽϩδοΫͷϛε
   
   • ʮ෭࡞༻͕͋Δ͔΋஌Εͳ͍ʯϩδοΫͷݕग़ϛε
   
   • Ұ෦ڧ੍Ϋϥογϡ͕ʮ෭࡞༻ͳ͠ʯʹͳΔϛε
   
   • ࠷దԽϩδοΫ͕ҙਤͨ͠ͷͰ͸ͳ͘ͳΔՄೳੑ
   

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6. Contributeͨ͠಺༰ ͷ͸ͳ͠
   

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7. Contributeͨ͠಺༰ ͷ͸ͳ͠
   • https://github.com/apple/swift/pull/31847
   
   • υΩϡϝϯτͰղઆ͍ͯ͠Δ Grammer ͷϛε
   
   • ࣗ෼͕ಡΜͩ SIL ͷίʔυ ͱҧ͏͔Βؾ͍ͮͨ
   
   • SIL ͷυΩϡϝϯτ͸ͨ·ʹΨόΨό
   

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8. Contributeͨ͠಺༰ ͷ͸ͳ͠
   • https://github.com/apple/swift/pull/33851
   
   • ࠷దԽϩδοΫͷϛε ← ࠓ೔͸ͬͪ͜ͷ࿩
   
   • ͜ͷ มߋͷཧղΛ௨ͯ͡SwiftίϯύΠϥʹೖ໳͢Δ
   

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9. Swift ͷίϯύΠϧϑϩʔ ͷ͸ͳ͠
   • Swift ͸͜ΜͳϑϩʔͰίϯύΠϧ͞ΕΔ
   
   • Swift ίϯύΠϥ΍Δͱ਌ͷإΑΓݟΔ͜ͱʹͳΔ
   

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10. Swift ͷίϯύΠϧϑϩʔ ͷ͸ͳ͠
    • օ͞Μ͓ͳ͡Έ Swift ίʔυ
    

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11. Swift ͷίϯύΠϧϑϩʔ ͷ͸ͳ͠
    • AST (ந৅ߏจ໦)
    
    • ϓϩάϥϜΛจ๏ͷߏ଄ʹ฿ͬͨ໦ߏ଄ʹͨ͠΋ͷ
    

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12. Swift ͷίϯύΠϧϑϩʔ ͷ͸ͳ͠
    • AST (ந৅ߏจ໦)
    
    • ԋࢉࢠͷ༏ઌ౓ͱ͔΋ߏจ໦ͷߏ଄Ͱܾ·ͬͨΓ
    

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13. Swift ͷίϯύΠϧϑϩʔ ͷ͸ͳ͠
    • SIL (Swift Intermediate Language)
    
    • Swift ಛ༗ͷந৅දݱ
    

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14. Swift ͷίϯύΠϧϑϩʔ ͷ͸ͳ͠
    • SIL (Swift Intermediate Language)
    
    • ͜͜ͰSwiftಛ༗ͷ ࠷దԽ౳͕ߦΘΕΔ
    
    • ࠓ೔ͷTopic
    

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15. Swift ͷίϯύΠϧϑϩʔ ͷ͸ͳ͠
    • LLVM IR => …
    
    • SIL Λ LLVM IR ʹ௚ͯ͠LLVM ʹ౤͛Δ
    
    • ͦͷ͋ͱϦϯΧʹ౤͛ΒΕͨΓ
    
    • όΠφϦ౳ʹͳΔ
    

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16. Swift Intermediate Language ͷ͸ͳ͠
    • Swift ಛ༗ͷதؒදݱ
    
    • ͜͜Ͱ Swiftಛ༗ͷ࠷దԽ͕ߦΘΕΔ
    

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17. Swift Intermediate Language ͷ͸ͳ͠
    • ͲͪΒ΋खݩʹ swiftc ίϚϯυ͕͋Ε͹ੜ੒Մೳ
    

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18. Swift Intermediate Language ͷ͸ͳ͠
    • ࢼ͠ʹ hello world! Λ SIL Ͱ ੜ੒ͯ͠ΈΔ
    
    • ࠓճ͸͕࣌ؒͳ͍ͷͰ raw SIL ͚ͩ
    

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19. Swift Intermediate Language ͷ͸ͳ͠
    • ௕͍ɾಡΈͮΒ͍ʢʁʣ
    

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20. Swift Intermediate Language ͷ͸ͳ͠
    • SIL͕swiftίʔυΑΓ௕͘ͳΔཧ༝
    
    • ؔ਺ʢԾ૝ʣςʔϒϧͷ৘ใ
    
    • ࡉ͔͍ϝϞϦͷ֬อ΍ϦϑΝϨϯεΧ΢ϯτͷ໋ྩ
    
    • Main ؔ਺ͳͲͷల։
    

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21. Swift Intermediate Language ͷ͸ͳ͠
    • SIL ͷߏ଄Λେ͖͍ॱʹ
    
    • SILModule (ιʔείʔυશମ)
    
    • SILFunction (֤ؔ਺)
    
    • SILBasicBlock (͍ΘΏΔείʔϓ)
    
    • SILInstruction (SILίʔυҰจҰจ)
    

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22. Swift Intermediate Language ͷ͸ͳ͠
    • ͍͍ͩͨ͜ΕΒΛཧղ͢ΔͱSIL͸ͬ͘͟ΓಡΊΔ
    
    • SIL͕swiftίʔυΑΓ௕͘ͳΔཧ༝
    
    • SIL ͷߏ଄ͷॱং
    

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23. Swift Intermediate Language ͷ͸ͳ͠
    • SILModule
    

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24. SILFunction
    

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25. SILBasicBlock
    

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26. SILBasicBlock
    

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27. SILBasicBlock
    Α͘ΈͨΒ bb0: ͬͯͳ͍ͬͯΔ
    -> basic block ͷུͰ͢
    ৚݅෼ذ౳ͰBasic Block͸૿͑Δ
    

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28. SILInstruction
    

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29. Swift Intermediate Language ͷ͸ͳ͠
    • ͜ͷߏ଄Λ஌͍ͬͯΔͱίϯύΠϥͷίʔυͷҰ෦͕

    ಡΊΔΑ͏ʹͳΔ
    
    • ͦΕ͕ SILOptimizer ͷίʔυ
    

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30. SILOptimizer ʹ͍ͭͯ
    • SIL (Swift Intermediate Language)
    
    • ͜͜ͰSwiftಛ༗ͷ ࠷దԽ౳͕ߦΘΕΔ
    

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31. SILOptimizer ʹ͍ͭͯ
    

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32. SILOptimizer ʹ͍ͭͯ
    

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33. SILOptimizer ʹ͍ͭͯ
    • raw SIL ੜ੒ޙɺSILOptimizer ʹΑͬͯ࠷దԽ͞ΕΔ
    
    • SILOptimizerதͷͨ͘͞Μ͋ΔPassͱ͍͏ϞδϡʔϧͰ
    ͦΕͧΕͷ໨తͷ࠷దԽ͕ߦΘΕΔ
    
    • ࠓ೔͸ͦͷPassͷίʔυΛಡΉ
    
    • Passͷίʔυͷجૅ͕٧·͍ͬͯΔ
    

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34. SILOptimizer ʹ͍ͭͯ
    • ࠓ೔͸ AssumeSingleThreaded ΛಡΉ
    
    • γϯάϧεϨου͚ͩͰಈ͔͞ΕΔͷʹಛԽ͢ΔΑ͏ʹ
    ͢Δ࠷దԽ
    
    • ΦϓγϣϯͰൃಈ͞ΕΔ
    
    • PassͷதͰଟ෼Ұ൪୹͍
    

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35. SILOptimizer ʹ͍ͭͯ
    

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36. SILOptimizer ʹ͍ͭͯ
    SILFunctionTransform Λܧঝ
    -> FuncitonΛ૸ࠪ͢ΔPassʹͳΔ
    

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37. SILOptimizer ʹ͍ͭͯ
    Ծ૝ؔ਺ run Λ࣮૷
    -> Pass ͷ࠷దԽϩδοΫ͸͜͜ʹॻ͘
    

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38. SILOptimizer ʹ͍ͭͯ
    ίϯύΠϥͷυϥΠόʢίϚϯυʣʹ౉͞ΕͨΦϓγϣϯΛΈΔ
    

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39. SILOptimizer ʹ͍ͭͯ
    ࠓݟ͍ͯΔؔ਺ΛSILFunctionܕͷ
    σʔλͱͯ͠ड͚औΔ
    

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40. SILOptimizer ʹ͍ͭͯ
    SILFunction͸SILBasicBlockͷCollection
    ͱͯ͠ѻ͑ΔʢͳͷͰBBʣ
    

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41. SILOptimizer ʹ͍ͭͯ
    SILBasicBlock͸SILInstructionͷCollection
    ͱͯ͠ѻ͑ΔʢͳͷͰIʣ
    

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42. SILOptimizer ʹ͍ͭͯ
    ͳͷͰɺ͜͜Ͱ͸ؔ਺಺ͷ
    InstructionΛ૸͍ࠪͯ͠Δ
    

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43. SILOptimizer ʹ͍ͭͯ
    ֤Instruction͸ܕͰදݱ͞Ε͍ͯΔ
    ΩϟετͰಛఆͷInstruction͔ௐ΂Δ
    

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44. SILOptimizer ʹ͍ͭͯ
    ϦϑΝϨϯεΧ΢ϯλؔ܎ͷInscrutionͳΒ
    NonAtomicʹ͢Δ
    

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45. SILOptimizer ʹ͍ͭͯ
    • AssumeSingleThreaded ʹ͍ͭͯ
    
    • Function಺ͷInstructionΛ૸ࠪ
    
    • ϦϑΝϨϯεΧ΢ϯλؔ܎ͩͬͨΒnon Atomicʹ͢Δ
    

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46. SILOptimizer ʹ͍ͭͯ
    • SILOptimizer ͷίʔυΛಡΉͱ͖ͷTips
    
    • ུޠ͕ଟ͍ͷͰίϯςΫετͰ൑அ͢Δ
    
    • ෳࡶͳϩδοΫ͸ C++ Λཧղ͔ͯ͠ΒಡΉ
    

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47. Contributeͨ͠಺༰ ͷ͸ͳ͠
    • ࠓճ௚ͨ͠ͷ͸ɺmayHaveSideEffect ͱ͍͏ؔ਺
    
    • ʮ෭࡞༻͕͋Δ͔΋஌Εͳ͍ʯInstructionΛݟΔ
    
    • SILInstruction ܕͷ ϝϯόม਺
    
    • Dead Code Elimination౳ʹ࢖ΘΕΔ
    

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48. Contributeͨ͠಺༰ ͷ͸ͳ͠
    • ͜ͷ৚݅ͷ̍൪໨͕ϛε͍ͬͯͨ(mayTrap ؔ਺)
    

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49. Contributeͨ͠಺༰ ͷ͸ͳ͠
    

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50. Contributeͨ͠಺༰ ͷ͸ͳ͠
    • ίϯύΠϥ಺ͷInstructionͷछྨͷදݱํ๏
    
    • ઌఔਃ্͛ͨ͠ܕʹΑΔදݱʢΩϟετʹΑΔ൑ผʣ
    
    • Enum ʹΑΔදݱʢswitch ͳͲ ʹΑΔ൑ผʣ
    
    • मਖ਼Օॴ͸ͬͪ͜Ͱදݱ͞Ε͍ͯΔ
    

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51. Contributeͨ͠಺༰ ͷ͸ͳ͠
    • ͪΐͬͱ̎൪Ίͷ঺հ
    

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52. Contributeͨ͠಺༰ ͷ͸ͳ͠
    • ϝϞϦΞΫηε͕ى͜Γͦ͏ͳInstructionͷݕ஌ํ๏
    
    • SILInstruction ͷଐੑΛݟΔ
    
    • LLVMͷInstruction ͷଐੑΛݟΔ
    
    • apply Instruction ͳΒݺͼग़͠ઌͷؔ਺ͷଐੑΛݟΔ
    
    • ͜͜Β΁Μͷॲཧ͸ͯͯ͝͝ͷXϚΫϩ͕ೖͬͨॲཧͳͷ
    ͰׂѪɻڵຯ͕͋ͬͨΒ࣭໰Ͱฉ͍͍ͯͩ͘͞
    

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53. Contributeͨ͠಺༰ ͷ͸ͳ͠
    

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54. Contributeͨ͠಺༰ ͷ͸ͳ͠
    

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55. Contributeͨ͠಺༰ ͷ͸ͳ͠
    • ΋͏গ͠஌Γ͍ͨํ͸ Θ͍Θ͍swiftc #20 ͷ๻ͷࢿྉΛݟ͍ͯͩ͘͞ 

    

    

    

    

    

    

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    https://speakerdeck.com/freddi/mayhavesideeffect
    

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56. Contributeͨ͠಺༰ ͷ͸ͳ͠
    • ͜ͷमਖ਼ՕॴͳΜͰݟ͚ͭͨͷʁ
    
    • झຯͰίϯύΠϥίʔυಡΜͰ͍ͨΒۮવΈ͚ͭͨ
    
    • bug.swift.orgͰόάνέοτʹ͸ͳ͔ͬͨ
    

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57. Contributeͨ͠಺༰ ͷ͸ͳ͠
    • PRग़ͨ͠ΒɺTest ॻ͍ͨΒϚʔδ͢ΔͱݴΘΕͨ
    
    • SILͷςετ΋ LLVMͷlitΛ࢖͍ͬͯΔΒ͍͠
    
    • LLVM Integrated Tester ͷུ
    
    • ͦΜͳ͜ΜͳͰϚʔδ͞Εͨ
    
    • ΂ͭʹόάνέοτΛ੾Δඞཁ͸ͳ͍Β͍͠
    

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58. Contributeͨ͠಺༰ ͷ͸ͳ͠
    • SIL.rst ͱ͍͏υΩϡϝϯτ͕SILʹ͍ͭͯৄ͘͠هࡌ
    
    • https://github.com/apple/swift/blob/main/docs/SIL.rst
    
    • ͨͩ͠ɺSIL.rst ͸ΨόΨόͳͷͰContributeνϟϯε͕

    ͨ͘͞Μ͋Δ
    
    • ͜͜΋मਖ਼Λ౤͛ͨ͜ͱ͕͋Δ
    

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59. ·ͱΊ
    • SILΛಡΈ͸͡ΊΔͱίϯύΠϥೖ໳΍Γ΍͍͢
    
    • SIL͕ಡΊΔͱ࠷దԽͷίʔυ͕ಡΊΔΑ͏ʹͳΔ
    
    • Contributeʹؔͯ͠΋ݫ͍͠ϧʔϧ͸ͳ͍ͷͰ

    ؾܰʹͰ͖Δ
    
    • ಛʹυΩϡϝϯτΨόΨόͳͷͰContributeͯ͠ΈΑ͏
    

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