1//===-- ARMUnwindOpAsm.h - ARM Unwind Opcodes Assembler ---------*- 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// This file declares the unwind opcode assmebler for ARM exception handling
11// table.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_LIB_TARGET_ARM_MCTARGETDESC_ARMUNWINDOPASM_H
16#define LLVM_LIB_TARGET_ARM_MCTARGETDESC_ARMUNWINDOPASM_H
17
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/Support/ARMEHABI.h"
20#include "llvm/Support/DataTypes.h"
21
22namespace llvm {
23
24class MCSymbol;
25
26class UnwindOpcodeAssembler {
27private:
28  llvm::SmallVector<uint8_t, 32> Ops;
29  llvm::SmallVector<unsigned, 8> OpBegins;
30  bool HasPersonality;
31
32public:
33  UnwindOpcodeAssembler()
34      : HasPersonality(0) {
35    OpBegins.push_back(0);
36  }
37
38  /// Reset the unwind opcode assembler.
39  void Reset() {
40    Ops.clear();
41    OpBegins.clear();
42    OpBegins.push_back(0);
43    HasPersonality = 0;
44  }
45
46  /// Set the personality
47  void setPersonality(const MCSymbol *Per) {
48    HasPersonality = 1;
49  }
50
51  /// Emit unwind opcodes for .save directives
52  void EmitRegSave(uint32_t RegSave);
53
54  /// Emit unwind opcodes for .vsave directives
55  void EmitVFPRegSave(uint32_t VFPRegSave);
56
57  /// Emit unwind opcodes to copy address from source register to $sp.
58  void EmitSetSP(uint16_t Reg);
59
60  /// Emit unwind opcodes to add $sp with an offset.
61  void EmitSPOffset(int64_t Offset);
62
63  /// Emit unwind raw opcodes
64  void EmitRaw(const SmallVectorImpl<uint8_t> &Opcodes) {
65    Ops.insert(Ops.end(), Opcodes.begin(), Opcodes.end());
66    OpBegins.push_back(OpBegins.back() + Opcodes.size());
67  }
68
69  /// Finalize the unwind opcode sequence for EmitBytes()
70  void Finalize(unsigned &PersonalityIndex,
71                SmallVectorImpl<uint8_t> &Result);
72
73private:
74  void EmitInt8(unsigned Opcode) {
75    Ops.push_back(Opcode & 0xff);
76    OpBegins.push_back(OpBegins.back() + 1);
77  }
78
79  void EmitInt16(unsigned Opcode) {
80    Ops.push_back((Opcode >> 8) & 0xff);
81    Ops.push_back(Opcode & 0xff);
82    OpBegins.push_back(OpBegins.back() + 2);
83  }
84
85  void EmitBytes(const uint8_t *Opcode, size_t Size) {
86    Ops.insert(Ops.end(), Opcode, Opcode + Size);
87    OpBegins.push_back(OpBegins.back() + Size);
88  }
89};
90
91} // namespace llvm
92
93#endif
94