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Diffstat (limited to 'clang/lib/CodeGen/CGCall.h')
| -rw-r--r-- | clang/lib/CodeGen/CGCall.h | 390 | 
1 files changed, 390 insertions, 0 deletions
| diff --git a/clang/lib/CodeGen/CGCall.h b/clang/lib/CodeGen/CGCall.h new file mode 100644 index 000000000000..cc11ded704ab --- /dev/null +++ b/clang/lib/CodeGen/CGCall.h @@ -0,0 +1,390 @@ +//===----- CGCall.h - Encapsulate calling convention details ----*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// These classes wrap the information about a call or function +// definition used to handle ABI compliancy. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CLANG_LIB_CODEGEN_CGCALL_H +#define LLVM_CLANG_LIB_CODEGEN_CGCALL_H + +#include "CGValue.h" +#include "EHScopeStack.h" +#include "clang/AST/CanonicalType.h" +#include "clang/AST/GlobalDecl.h" +#include "clang/AST/Type.h" +#include "llvm/IR/Value.h" + +// FIXME: Restructure so we don't have to expose so much stuff. +#include "ABIInfo.h" + +namespace llvm { +class AttributeList; +class Function; +class Type; +class Value; +} + +namespace clang { +  class ASTContext; +  class Decl; +  class FunctionDecl; +  class ObjCMethodDecl; +  class VarDecl; + +namespace CodeGen { + +/// Abstract information about a function or function prototype. +class CGCalleeInfo { +  /// The function prototype of the callee. +  const FunctionProtoType *CalleeProtoTy; +  /// The function declaration of the callee. +  GlobalDecl CalleeDecl; + +public: +  explicit CGCalleeInfo() : CalleeProtoTy(nullptr), CalleeDecl() {} +  CGCalleeInfo(const FunctionProtoType *calleeProtoTy, GlobalDecl calleeDecl) +      : CalleeProtoTy(calleeProtoTy), CalleeDecl(calleeDecl) {} +  CGCalleeInfo(const FunctionProtoType *calleeProtoTy) +      : CalleeProtoTy(calleeProtoTy), CalleeDecl() {} +  CGCalleeInfo(GlobalDecl calleeDecl) +      : CalleeProtoTy(nullptr), CalleeDecl(calleeDecl) {} + +  const FunctionProtoType *getCalleeFunctionProtoType() const { +    return CalleeProtoTy; +  } +  const GlobalDecl getCalleeDecl() const { return CalleeDecl; } +  }; + +  /// All available information about a concrete callee. +  class CGCallee { +    enum class SpecialKind : uintptr_t { +      Invalid, +      Builtin, +      PseudoDestructor, +      Virtual, + +      Last = Virtual +    }; + +    struct BuiltinInfoStorage { +      const FunctionDecl *Decl; +      unsigned ID; +    }; +    struct PseudoDestructorInfoStorage { +      const CXXPseudoDestructorExpr *Expr; +    }; +    struct VirtualInfoStorage { +      const CallExpr *CE; +      GlobalDecl MD; +      Address Addr; +      llvm::FunctionType *FTy; +    }; + +    SpecialKind KindOrFunctionPointer; +    union { +      CGCalleeInfo AbstractInfo; +      BuiltinInfoStorage BuiltinInfo; +      PseudoDestructorInfoStorage PseudoDestructorInfo; +      VirtualInfoStorage VirtualInfo; +    }; + +    explicit CGCallee(SpecialKind kind) : KindOrFunctionPointer(kind) {} + +    CGCallee(const FunctionDecl *builtinDecl, unsigned builtinID) +        : KindOrFunctionPointer(SpecialKind::Builtin) { +      BuiltinInfo.Decl = builtinDecl; +      BuiltinInfo.ID = builtinID; +    } + +  public: +    CGCallee() : KindOrFunctionPointer(SpecialKind::Invalid) {} + +    /// Construct a callee.  Call this constructor directly when this +    /// isn't a direct call. +    CGCallee(const CGCalleeInfo &abstractInfo, llvm::Value *functionPtr) +        : KindOrFunctionPointer(SpecialKind(uintptr_t(functionPtr))) { +      AbstractInfo = abstractInfo; +      assert(functionPtr && "configuring callee without function pointer"); +      assert(functionPtr->getType()->isPointerTy()); +      assert(functionPtr->getType()->getPointerElementType()->isFunctionTy()); +    } + +    static CGCallee forBuiltin(unsigned builtinID, +                               const FunctionDecl *builtinDecl) { +      CGCallee result(SpecialKind::Builtin); +      result.BuiltinInfo.Decl = builtinDecl; +      result.BuiltinInfo.ID = builtinID; +      return result; +    } + +    static CGCallee forPseudoDestructor(const CXXPseudoDestructorExpr *E) { +      CGCallee result(SpecialKind::PseudoDestructor); +      result.PseudoDestructorInfo.Expr = E; +      return result; +    } + +    static CGCallee forDirect(llvm::Constant *functionPtr, +                        const CGCalleeInfo &abstractInfo = CGCalleeInfo()) { +      return CGCallee(abstractInfo, functionPtr); +    } + +    static CGCallee +    forDirect(llvm::FunctionCallee functionPtr, +              const CGCalleeInfo &abstractInfo = CGCalleeInfo()) { +      return CGCallee(abstractInfo, functionPtr.getCallee()); +    } + +    static CGCallee forVirtual(const CallExpr *CE, GlobalDecl MD, Address Addr, +                               llvm::FunctionType *FTy) { +      CGCallee result(SpecialKind::Virtual); +      result.VirtualInfo.CE = CE; +      result.VirtualInfo.MD = MD; +      result.VirtualInfo.Addr = Addr; +      result.VirtualInfo.FTy = FTy; +      return result; +    } + +    bool isBuiltin() const { +      return KindOrFunctionPointer == SpecialKind::Builtin; +    } +    const FunctionDecl *getBuiltinDecl() const { +      assert(isBuiltin()); +      return BuiltinInfo.Decl; +    } +    unsigned getBuiltinID() const { +      assert(isBuiltin()); +      return BuiltinInfo.ID; +    } + +    bool isPseudoDestructor() const { +      return KindOrFunctionPointer == SpecialKind::PseudoDestructor; +    } +    const CXXPseudoDestructorExpr *getPseudoDestructorExpr() const { +      assert(isPseudoDestructor()); +      return PseudoDestructorInfo.Expr; +    } + +    bool isOrdinary() const { +      return uintptr_t(KindOrFunctionPointer) > uintptr_t(SpecialKind::Last); +    } +    CGCalleeInfo getAbstractInfo() const { +      if (isVirtual()) +        return VirtualInfo.MD; +      assert(isOrdinary()); +      return AbstractInfo; +    } +    llvm::Value *getFunctionPointer() const { +      assert(isOrdinary()); +      return reinterpret_cast<llvm::Value*>(uintptr_t(KindOrFunctionPointer)); +    } +    void setFunctionPointer(llvm::Value *functionPtr) { +      assert(isOrdinary()); +      KindOrFunctionPointer = SpecialKind(uintptr_t(functionPtr)); +    } + +    bool isVirtual() const { +      return KindOrFunctionPointer == SpecialKind::Virtual; +    } +    const CallExpr *getVirtualCallExpr() const { +      assert(isVirtual()); +      return VirtualInfo.CE; +    } +    GlobalDecl getVirtualMethodDecl() const { +      assert(isVirtual()); +      return VirtualInfo.MD; +    } +    Address getThisAddress() const { +      assert(isVirtual()); +      return VirtualInfo.Addr; +    } +    llvm::FunctionType *getVirtualFunctionType() const { +      assert(isVirtual()); +      return VirtualInfo.FTy; +    } + +    /// If this is a delayed callee computation of some sort, prepare +    /// a concrete callee. +    CGCallee prepareConcreteCallee(CodeGenFunction &CGF) const; +  }; + +  struct CallArg { +  private: +    union { +      RValue RV; +      LValue LV; /// The argument is semantically a load from this l-value. +    }; +    bool HasLV; + +    /// A data-flow flag to make sure getRValue and/or copyInto are not +    /// called twice for duplicated IR emission. +    mutable bool IsUsed; + +  public: +    QualType Ty; +    CallArg(RValue rv, QualType ty) +        : RV(rv), HasLV(false), IsUsed(false), Ty(ty) {} +    CallArg(LValue lv, QualType ty) +        : LV(lv), HasLV(true), IsUsed(false), Ty(ty) {} +    bool hasLValue() const { return HasLV; } +    QualType getType() const { return Ty; } + +    /// \returns an independent RValue. If the CallArg contains an LValue, +    /// a temporary copy is returned. +    RValue getRValue(CodeGenFunction &CGF) const; + +    LValue getKnownLValue() const { +      assert(HasLV && !IsUsed); +      return LV; +    } +    RValue getKnownRValue() const { +      assert(!HasLV && !IsUsed); +      return RV; +    } +    void setRValue(RValue _RV) { +      assert(!HasLV); +      RV = _RV; +    } + +    bool isAggregate() const { return HasLV || RV.isAggregate(); } + +    void copyInto(CodeGenFunction &CGF, Address A) const; +  }; + +  /// CallArgList - Type for representing both the value and type of +  /// arguments in a call. +  class CallArgList : +    public SmallVector<CallArg, 8> { +  public: +    CallArgList() : StackBase(nullptr) {} + +    struct Writeback { +      /// The original argument.  Note that the argument l-value +      /// is potentially null. +      LValue Source; + +      /// The temporary alloca. +      Address Temporary; + +      /// A value to "use" after the writeback, or null. +      llvm::Value *ToUse; +    }; + +    struct CallArgCleanup { +      EHScopeStack::stable_iterator Cleanup; + +      /// The "is active" insertion point.  This instruction is temporary and +      /// will be removed after insertion. +      llvm::Instruction *IsActiveIP; +    }; + +    void add(RValue rvalue, QualType type) { push_back(CallArg(rvalue, type)); } + +    void addUncopiedAggregate(LValue LV, QualType type) { +      push_back(CallArg(LV, type)); +    } + +    /// Add all the arguments from another CallArgList to this one. After doing +    /// this, the old CallArgList retains its list of arguments, but must not +    /// be used to emit a call. +    void addFrom(const CallArgList &other) { +      insert(end(), other.begin(), other.end()); +      Writebacks.insert(Writebacks.end(), +                        other.Writebacks.begin(), other.Writebacks.end()); +      CleanupsToDeactivate.insert(CleanupsToDeactivate.end(), +                                  other.CleanupsToDeactivate.begin(), +                                  other.CleanupsToDeactivate.end()); +      assert(!(StackBase && other.StackBase) && "can't merge stackbases"); +      if (!StackBase) +        StackBase = other.StackBase; +    } + +    void addWriteback(LValue srcLV, Address temporary, +                      llvm::Value *toUse) { +      Writeback writeback = { srcLV, temporary, toUse }; +      Writebacks.push_back(writeback); +    } + +    bool hasWritebacks() const { return !Writebacks.empty(); } + +    typedef llvm::iterator_range<SmallVectorImpl<Writeback>::const_iterator> +      writeback_const_range; + +    writeback_const_range writebacks() const { +      return writeback_const_range(Writebacks.begin(), Writebacks.end()); +    } + +    void addArgCleanupDeactivation(EHScopeStack::stable_iterator Cleanup, +                                   llvm::Instruction *IsActiveIP) { +      CallArgCleanup ArgCleanup; +      ArgCleanup.Cleanup = Cleanup; +      ArgCleanup.IsActiveIP = IsActiveIP; +      CleanupsToDeactivate.push_back(ArgCleanup); +    } + +    ArrayRef<CallArgCleanup> getCleanupsToDeactivate() const { +      return CleanupsToDeactivate; +    } + +    void allocateArgumentMemory(CodeGenFunction &CGF); +    llvm::Instruction *getStackBase() const { return StackBase; } +    void freeArgumentMemory(CodeGenFunction &CGF) const; + +    /// Returns if we're using an inalloca struct to pass arguments in +    /// memory. +    bool isUsingInAlloca() const { return StackBase; } + +  private: +    SmallVector<Writeback, 1> Writebacks; + +    /// Deactivate these cleanups immediately before making the call.  This +    /// is used to cleanup objects that are owned by the callee once the call +    /// occurs. +    SmallVector<CallArgCleanup, 1> CleanupsToDeactivate; + +    /// The stacksave call.  It dominates all of the argument evaluation. +    llvm::CallInst *StackBase; +  }; + +  /// FunctionArgList - Type for representing both the decl and type +  /// of parameters to a function. The decl must be either a +  /// ParmVarDecl or ImplicitParamDecl. +  class FunctionArgList : public SmallVector<const VarDecl*, 16> { +  }; + +  /// ReturnValueSlot - Contains the address where the return value of a +  /// function can be stored, and whether the address is volatile or not. +  class ReturnValueSlot { +    llvm::PointerIntPair<llvm::Value *, 2, unsigned int> Value; +    CharUnits Alignment; + +    // Return value slot flags +    enum Flags { +      IS_VOLATILE = 0x1, +      IS_UNUSED = 0x2, +    }; + +  public: +    ReturnValueSlot() {} +    ReturnValueSlot(Address Addr, bool IsVolatile, bool IsUnused = false) +      : Value(Addr.isValid() ? Addr.getPointer() : nullptr, +              (IsVolatile ? IS_VOLATILE : 0) | (IsUnused ? IS_UNUSED : 0)), +        Alignment(Addr.isValid() ? Addr.getAlignment() : CharUnits::Zero()) {} + +    bool isNull() const { return !getValue().isValid(); } + +    bool isVolatile() const { return Value.getInt() & IS_VOLATILE; } +    Address getValue() const { return Address(Value.getPointer(), Alignment); } +    bool isUnused() const { return Value.getInt() & IS_UNUSED; } +  }; + +}  // end namespace CodeGen +}  // end namespace clang + +#endif | 
