1 //===----- CGCall.h - Encapsulate calling convention details ----*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // These classes wrap the information about a call or function 11 // definition used to handle ABI compliancy. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CLANG_LIB_CODEGEN_CGCALL_H 16 #define LLVM_CLANG_LIB_CODEGEN_CGCALL_H 17 18 #include "CGValue.h" 19 #include "EHScopeStack.h" 20 #include "clang/AST/CanonicalType.h" 21 #include "clang/AST/Type.h" 22 #include "llvm/ADT/FoldingSet.h" 23 #include "llvm/IR/Value.h" 24 25 // FIXME: Restructure so we don't have to expose so much stuff. 26 #include "ABIInfo.h" 27 28 namespace llvm { 29 class AttributeSet; 30 class Function; 31 class Type; 32 class Value; 33 } 34 35 namespace clang { 36 class ASTContext; 37 class Decl; 38 class FunctionDecl; 39 class ObjCMethodDecl; 40 class VarDecl; 41 42 namespace CodeGen { 43 typedef SmallVector<llvm::AttributeSet, 8> AttributeListType; 44 45 struct CallArg { 46 RValue RV; 47 QualType Ty; 48 bool NeedsCopy; CallArgCallArg49 CallArg(RValue rv, QualType ty, bool needscopy) 50 : RV(rv), Ty(ty), NeedsCopy(needscopy) 51 { } 52 }; 53 54 /// CallArgList - Type for representing both the value and type of 55 /// arguments in a call. 56 class CallArgList : 57 public SmallVector<CallArg, 16> { 58 public: CallArgList()59 CallArgList() : StackBase(nullptr), StackBaseMem(nullptr) {} 60 61 struct Writeback { 62 /// The original argument. Note that the argument l-value 63 /// is potentially null. 64 LValue Source; 65 66 /// The temporary alloca. 67 llvm::Value *Temporary; 68 69 /// A value to "use" after the writeback, or null. 70 llvm::Value *ToUse; 71 }; 72 73 struct CallArgCleanup { 74 EHScopeStack::stable_iterator Cleanup; 75 76 /// The "is active" insertion point. This instruction is temporary and 77 /// will be removed after insertion. 78 llvm::Instruction *IsActiveIP; 79 }; 80 81 void add(RValue rvalue, QualType type, bool needscopy = false) { 82 push_back(CallArg(rvalue, type, needscopy)); 83 } 84 addFrom(const CallArgList & other)85 void addFrom(const CallArgList &other) { 86 insert(end(), other.begin(), other.end()); 87 Writebacks.insert(Writebacks.end(), 88 other.Writebacks.begin(), other.Writebacks.end()); 89 } 90 addWriteback(LValue srcLV,llvm::Value * temporary,llvm::Value * toUse)91 void addWriteback(LValue srcLV, llvm::Value *temporary, 92 llvm::Value *toUse) { 93 Writeback writeback; 94 writeback.Source = srcLV; 95 writeback.Temporary = temporary; 96 writeback.ToUse = toUse; 97 Writebacks.push_back(writeback); 98 } 99 hasWritebacks()100 bool hasWritebacks() const { return !Writebacks.empty(); } 101 102 typedef llvm::iterator_range<SmallVectorImpl<Writeback>::const_iterator> 103 writeback_const_range; 104 writebacks()105 writeback_const_range writebacks() const { 106 return writeback_const_range(Writebacks.begin(), Writebacks.end()); 107 } 108 addArgCleanupDeactivation(EHScopeStack::stable_iterator Cleanup,llvm::Instruction * IsActiveIP)109 void addArgCleanupDeactivation(EHScopeStack::stable_iterator Cleanup, 110 llvm::Instruction *IsActiveIP) { 111 CallArgCleanup ArgCleanup; 112 ArgCleanup.Cleanup = Cleanup; 113 ArgCleanup.IsActiveIP = IsActiveIP; 114 CleanupsToDeactivate.push_back(ArgCleanup); 115 } 116 getCleanupsToDeactivate()117 ArrayRef<CallArgCleanup> getCleanupsToDeactivate() const { 118 return CleanupsToDeactivate; 119 } 120 121 void allocateArgumentMemory(CodeGenFunction &CGF); getStackBase()122 llvm::Instruction *getStackBase() const { return StackBase; } 123 void freeArgumentMemory(CodeGenFunction &CGF) const; 124 125 /// \brief Returns if we're using an inalloca struct to pass arguments in 126 /// memory. isUsingInAlloca()127 bool isUsingInAlloca() const { return StackBase; } 128 129 private: 130 SmallVector<Writeback, 1> Writebacks; 131 132 /// Deactivate these cleanups immediately before making the call. This 133 /// is used to cleanup objects that are owned by the callee once the call 134 /// occurs. 135 SmallVector<CallArgCleanup, 1> CleanupsToDeactivate; 136 137 /// The stacksave call. It dominates all of the argument evaluation. 138 llvm::CallInst *StackBase; 139 140 /// The alloca holding the stackbase. We need it to maintain SSA form. 141 llvm::AllocaInst *StackBaseMem; 142 143 /// The iterator pointing to the stack restore cleanup. We manually run and 144 /// deactivate this cleanup after the call in the unexceptional case because 145 /// it doesn't run in the normal order. 146 EHScopeStack::stable_iterator StackCleanup; 147 }; 148 149 /// FunctionArgList - Type for representing both the decl and type 150 /// of parameters to a function. The decl must be either a 151 /// ParmVarDecl or ImplicitParamDecl. 152 class FunctionArgList : public SmallVector<const VarDecl*, 16> { 153 }; 154 155 /// ReturnValueSlot - Contains the address where the return value of a 156 /// function can be stored, and whether the address is volatile or not. 157 class ReturnValueSlot { 158 llvm::PointerIntPair<llvm::Value *, 1, bool> Value; 159 160 public: ReturnValueSlot()161 ReturnValueSlot() {} ReturnValueSlot(llvm::Value * Value,bool IsVolatile)162 ReturnValueSlot(llvm::Value *Value, bool IsVolatile) 163 : Value(Value, IsVolatile) {} 164 isNull()165 bool isNull() const { return !getValue(); } 166 isVolatile()167 bool isVolatile() const { return Value.getInt(); } getValue()168 llvm::Value *getValue() const { return Value.getPointer(); } 169 }; 170 171 } // end namespace CodeGen 172 } // end namespace clang 173 174 #endif 175