[Coroutines] Move Shape to its own header (#108242)

* To create custom ABIs plugin libraries need access to CoroShape.
* As a step in enabling plugin libraries, move Shape into its own header
* The header will eventually be moved into include/llvm/Transforms/Coroutines

See RFC for more info:
https://discourse.llvm.org/t/rfc-abi-objects-for-coroutines/81057

Author: TylerNowicki

llvm/lib/Transforms/Coroutines/CoroEarly.cpp

@@ -8,6 +8,7 @@
 
 #include "llvm/Transforms/Coroutines/CoroEarly.h"
 #include "CoroInternal.h"
+#include "CoroShape.h"
 #include "llvm/IR/DIBuilder.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IRBuilder.h"

llvm/lib/Transforms/Coroutines/CoroInternal.h

@@ -12,6 +12,7 @@
 #define LLVM_LIB_TRANSFORMS_COROUTINES_COROINTERNAL_H
 
 #include "CoroInstr.h"
+#include "CoroShape.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/IRBuilder.h"
 
@@ -58,229 +59,6 @@ struct LowererBase {
   CallInst *makeSubFnCall(Value *Arg, int Index, Instruction *InsertPt);
 };
 
-enum class ABI {
-  /// The "resume-switch" lowering, where there are separate resume and
-  /// destroy functions that are shared between all suspend points.  The
-  /// coroutine frame implicitly stores the resume and destroy functions,
-  /// the current index, and any promise value.
-  Switch,
-
-  /// The "returned-continuation" lowering, where each suspend point creates a
-  /// single continuation function that is used for both resuming and
-  /// destroying.  Does not support promises.
-  Retcon,
-
-  /// The "unique returned-continuation" lowering, where each suspend point
-  /// creates a single continuation function that is used for both resuming
-  /// and destroying.  Does not support promises.  The function is known to
-  /// suspend at most once during its execution, and the return value of
-  /// the continuation is void.
-  RetconOnce,
-
-  /// The "async continuation" lowering, where each suspend point creates a
-  /// single continuation function. The continuation function is available as an
-  /// intrinsic.
-  Async,
-};
-
-// Holds structural Coroutine Intrinsics for a particular function and other
-// values used during CoroSplit pass.
-struct LLVM_LIBRARY_VISIBILITY Shape {
-  CoroBeginInst *CoroBegin;
-  SmallVector<AnyCoroEndInst *, 4> CoroEnds;
-  SmallVector<CoroSizeInst *, 2> CoroSizes;
-  SmallVector<CoroAlignInst *, 2> CoroAligns;
-  SmallVector<AnyCoroSuspendInst *, 4> CoroSuspends;
-  SmallVector<CallInst*, 2> SwiftErrorOps;
-  SmallVector<CoroAwaitSuspendInst *, 4> CoroAwaitSuspends;
-  SmallVector<CallInst *, 2> SymmetricTransfers;
-
-  // Field indexes for special fields in the switch lowering.
-  struct SwitchFieldIndex {
-    enum {
-      Resume,
-      Destroy
-
-      // The promise field is always at a fixed offset from the start of
-      // frame given its type, but the index isn't a constant for all
-      // possible frames.
-
-      // The switch-index field isn't at a fixed offset or index, either;
-      // we just work it in where it fits best.
-    };
-  };
-
-  coro::ABI ABI;
-
-  StructType *FrameTy;
-  Align FrameAlign;
-  uint64_t FrameSize;
-  Value *FramePtr;
-  BasicBlock *AllocaSpillBlock;
-
-  /// This would only be true if optimization are enabled.
-  bool OptimizeFrame;
-
-  struct SwitchLoweringStorage {
-    SwitchInst *ResumeSwitch;
-    AllocaInst *PromiseAlloca;
-    BasicBlock *ResumeEntryBlock;
-    unsigned IndexField;
-    unsigned IndexAlign;
-    unsigned IndexOffset;
-    bool HasFinalSuspend;
-    bool HasUnwindCoroEnd;
-  };
-
-  struct RetconLoweringStorage {
-    Function *ResumePrototype;
-    Function *Alloc;
-    Function *Dealloc;
-    BasicBlock *ReturnBlock;
-    bool IsFrameInlineInStorage;
-  };
-
-  struct AsyncLoweringStorage {
-    Value *Context;
-    CallingConv::ID AsyncCC;
-    unsigned ContextArgNo;
-    uint64_t ContextHeaderSize;
-    uint64_t ContextAlignment;
-    uint64_t FrameOffset; // Start of the frame.
-    uint64_t ContextSize; // Includes frame size.
-    GlobalVariable *AsyncFuncPointer;
-
-    Align getContextAlignment() const { return Align(ContextAlignment); }
-  };
-
-  union {
-    SwitchLoweringStorage SwitchLowering;
-    RetconLoweringStorage RetconLowering;
-    AsyncLoweringStorage AsyncLowering;
-  };
-
-  CoroIdInst *getSwitchCoroId() const {
-    assert(ABI == coro::ABI::Switch);
-    return cast<CoroIdInst>(CoroBegin->getId());
-  }
-
-  AnyCoroIdRetconInst *getRetconCoroId() const {
-    assert(ABI == coro::ABI::Retcon ||
-           ABI == coro::ABI::RetconOnce);
-    return cast<AnyCoroIdRetconInst>(CoroBegin->getId());
-  }
-
-  CoroIdAsyncInst *getAsyncCoroId() const {
-    assert(ABI == coro::ABI::Async);
-    return cast<CoroIdAsyncInst>(CoroBegin->getId());
-  }
-
-  unsigned getSwitchIndexField() const {
-    assert(ABI == coro::ABI::Switch);
-    assert(FrameTy && "frame type not assigned");
-    return SwitchLowering.IndexField;
-  }
-  IntegerType *getIndexType() const {
-    assert(ABI == coro::ABI::Switch);
-    assert(FrameTy && "frame type not assigned");
-    return cast<IntegerType>(FrameTy->getElementType(getSwitchIndexField()));
-  }
-  ConstantInt *getIndex(uint64_t Value) const {
-    return ConstantInt::get(getIndexType(), Value);
-  }
-
-  PointerType *getSwitchResumePointerType() const {
-    assert(ABI == coro::ABI::Switch);
-  assert(FrameTy && "frame type not assigned");
-  return cast<PointerType>(FrameTy->getElementType(SwitchFieldIndex::Resume));
-  }
-
-  FunctionType *getResumeFunctionType() const {
-    switch (ABI) {
-    case coro::ABI::Switch:
-      return FunctionType::get(Type::getVoidTy(FrameTy->getContext()),
-                               PointerType::getUnqual(FrameTy->getContext()),
-                               /*IsVarArg=*/false);
-    case coro::ABI::Retcon:
-    case coro::ABI::RetconOnce:
-      return RetconLowering.ResumePrototype->getFunctionType();
-    case coro::ABI::Async:
-      // Not used. The function type depends on the active suspend.
-      return nullptr;
-    }
-
-    llvm_unreachable("Unknown coro::ABI enum");
-  }
-
-  ArrayRef<Type*> getRetconResultTypes() const {
-    assert(ABI == coro::ABI::Retcon ||
-           ABI == coro::ABI::RetconOnce);
-    auto FTy = CoroBegin->getFunction()->getFunctionType();
-
-    // The safety of all this is checked by checkWFRetconPrototype.
-    if (auto STy = dyn_cast<StructType>(FTy->getReturnType())) {
-      return STy->elements().slice(1);
-    } else {
-      return ArrayRef<Type*>();
-    }
-  }
-
-  ArrayRef<Type*> getRetconResumeTypes() const {
-    assert(ABI == coro::ABI::Retcon ||
-           ABI == coro::ABI::RetconOnce);
-
-    // The safety of all this is checked by checkWFRetconPrototype.
-    auto FTy = RetconLowering.ResumePrototype->getFunctionType();
-    return FTy->params().slice(1);
-  }
-
-  CallingConv::ID getResumeFunctionCC() const {
-    switch (ABI) {
-    case coro::ABI::Switch:
-      return CallingConv::Fast;
-
-    case coro::ABI::Retcon:
-    case coro::ABI::RetconOnce:
-      return RetconLowering.ResumePrototype->getCallingConv();
-    case coro::ABI::Async:
-      return AsyncLowering.AsyncCC;
-    }
-    llvm_unreachable("Unknown coro::ABI enum");
-  }
-
-  AllocaInst *getPromiseAlloca() const {
-    if (ABI == coro::ABI::Switch)
-      return SwitchLowering.PromiseAlloca;
-    return nullptr;
-  }
-
-  BasicBlock::iterator getInsertPtAfterFramePtr() const {
-    if (auto *I = dyn_cast<Instruction>(FramePtr)) {
-      BasicBlock::iterator It = std::next(I->getIterator());
-      It.setHeadBit(true); // Copy pre-RemoveDIs behaviour.
-      return It;
-    }
-    return cast<Argument>(FramePtr)->getParent()->getEntryBlock().begin();
-  }
-
-  /// Allocate memory according to the rules of the active lowering.
-  ///
-  /// \param CG - if non-null, will be updated for the new call
-  Value *emitAlloc(IRBuilder<> &Builder, Value *Size, CallGraph *CG) const;
-
-  /// Deallocate memory according to the rules of the active lowering.
-  ///
-  /// \param CG - if non-null, will be updated for the new call
-  void emitDealloc(IRBuilder<> &Builder, Value *Ptr, CallGraph *CG) const;
-
-  Shape() = default;
-  explicit Shape(Function &F, bool OptimizeFrame = false)
-      : OptimizeFrame(OptimizeFrame) {
-    buildFrom(F);
-  }
-  void buildFrom(Function &F);
-};
-
 bool defaultMaterializable(Instruction &V);
 void normalizeCoroutine(Function &F, coro::Shape &Shape,
                         TargetTransformInfo &TTI);