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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 |