1 //===----- CGCall.h - Encapsulate calling convention details ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // These classes wrap the information about a call or function
11 // definition used to handle ABI compliancy.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CLANG_LIB_CODEGEN_CGCALL_H
16 #define LLVM_CLANG_LIB_CODEGEN_CGCALL_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"
25 // FIXME: Restructure so we don't have to expose so much stuff.
43 typedef SmallVector<llvm::AttributeSet, 8> AttributeListType;
49 CallArg(RValue rv, QualType ty, bool needscopy)
50 : RV(rv), Ty(ty), NeedsCopy(needscopy)
54 /// CallArgList - Type for representing both the value and type of
55 /// arguments in a call.
57 public SmallVector<CallArg, 16> {
59 CallArgList() : StackBase(nullptr) {}
62 /// The original argument. Note that the argument l-value
63 /// is potentially null.
66 /// The temporary alloca.
69 /// A value to "use" after the writeback, or null.
73 struct CallArgCleanup {
74 EHScopeStack::stable_iterator Cleanup;
76 /// The "is active" insertion point. This instruction is temporary and
77 /// will be removed after insertion.
78 llvm::Instruction *IsActiveIP;
81 void add(RValue rvalue, QualType type, bool needscopy = false) {
82 push_back(CallArg(rvalue, type, needscopy));
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());
91 void addWriteback(LValue srcLV, Address temporary,
93 Writeback writeback = { srcLV, temporary, toUse };
94 Writebacks.push_back(writeback);
97 bool hasWritebacks() const { return !Writebacks.empty(); }
99 typedef llvm::iterator_range<SmallVectorImpl<Writeback>::const_iterator>
100 writeback_const_range;
102 writeback_const_range writebacks() const {
103 return writeback_const_range(Writebacks.begin(), Writebacks.end());
106 void addArgCleanupDeactivation(EHScopeStack::stable_iterator Cleanup,
107 llvm::Instruction *IsActiveIP) {
108 CallArgCleanup ArgCleanup;
109 ArgCleanup.Cleanup = Cleanup;
110 ArgCleanup.IsActiveIP = IsActiveIP;
111 CleanupsToDeactivate.push_back(ArgCleanup);
114 ArrayRef<CallArgCleanup> getCleanupsToDeactivate() const {
115 return CleanupsToDeactivate;
118 void allocateArgumentMemory(CodeGenFunction &CGF);
119 llvm::Instruction *getStackBase() const { return StackBase; }
120 void freeArgumentMemory(CodeGenFunction &CGF) const;
122 /// \brief Returns if we're using an inalloca struct to pass arguments in
124 bool isUsingInAlloca() const { return StackBase; }
127 SmallVector<Writeback, 1> Writebacks;
129 /// Deactivate these cleanups immediately before making the call. This
130 /// is used to cleanup objects that are owned by the callee once the call
132 SmallVector<CallArgCleanup, 1> CleanupsToDeactivate;
134 /// The stacksave call. It dominates all of the argument evaluation.
135 llvm::CallInst *StackBase;
137 /// The iterator pointing to the stack restore cleanup. We manually run and
138 /// deactivate this cleanup after the call in the unexceptional case because
139 /// it doesn't run in the normal order.
140 EHScopeStack::stable_iterator StackCleanup;
143 /// FunctionArgList - Type for representing both the decl and type
144 /// of parameters to a function. The decl must be either a
145 /// ParmVarDecl or ImplicitParamDecl.
146 class FunctionArgList : public SmallVector<const VarDecl*, 16> {
149 /// ReturnValueSlot - Contains the address where the return value of a
150 /// function can be stored, and whether the address is volatile or not.
151 class ReturnValueSlot {
152 llvm::PointerIntPair<llvm::Value *, 2, unsigned int> Value;
155 // Return value slot flags
163 ReturnValueSlot(Address Addr, bool IsVolatile, bool IsUnused = false)
164 : Value(Addr.isValid() ? Addr.getPointer() : nullptr,
165 (IsVolatile ? IS_VOLATILE : 0) | (IsUnused ? IS_UNUSED : 0)),
166 Alignment(Addr.isValid() ? Addr.getAlignment() : CharUnits::Zero()) {}
168 bool isNull() const { return !getValue().isValid(); }
170 bool isVolatile() const { return Value.getInt() & IS_VOLATILE; }
171 Address getValue() const { return Address(Value.getPointer(), Alignment); }
172 bool isUnused() const { return Value.getInt() & IS_UNUSED; }
175 } // end namespace CodeGen
176 } // end namespace clang