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ARMUnwindOpAsm.h
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1 //===-- ARMUnwindOpAsm.h - ARM Unwind Opcodes Assembler ---------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file declares the unwind opcode assmebler for ARM exception handling
10 // table.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_ARM_MCTARGETDESC_ARMUNWINDOPASM_H
15 #define LLVM_LIB_TARGET_ARM_MCTARGETDESC_ARMUNWINDOPASM_H
16 
17 #include "llvm/ADT/SmallVector.h"
18 #include <cstddef>
19 #include <cstdint>
20 
21 namespace llvm {
22 
23 class MCSymbol;
24 
26 private:
28  SmallVector<unsigned, 8> OpBegins;
29  bool HasPersonality = false;
30 
31 public:
33  OpBegins.push_back(0);
34  }
35 
36  /// Reset the unwind opcode assembler.
37  void Reset() {
38  Ops.clear();
39  OpBegins.clear();
40  OpBegins.push_back(0);
41  HasPersonality = false;
42  }
43 
44  /// Set the personality
45  void setPersonality(const MCSymbol *Per) {
46  HasPersonality = true;
47  }
48 
49  /// Emit unwind opcodes for .save directives
50  void EmitRegSave(uint32_t RegSave);
51 
52  /// Emit unwind opcodes for .vsave directives
53  void EmitVFPRegSave(uint32_t VFPRegSave);
54 
55  /// Emit unwind opcodes to copy address from source register to $sp.
56  void EmitSetSP(uint16_t Reg);
57 
58  /// Emit unwind opcodes to add $sp with an offset.
59  void EmitSPOffset(int64_t Offset);
60 
61  /// Emit unwind raw opcodes
62  void EmitRaw(const SmallVectorImpl<uint8_t> &Opcodes) {
63  Ops.insert(Ops.end(), Opcodes.begin(), Opcodes.end());
64  OpBegins.push_back(OpBegins.back() + Opcodes.size());
65  }
66 
67  /// Finalize the unwind opcode sequence for EmitBytes()
68  void Finalize(unsigned &PersonalityIndex,
69  SmallVectorImpl<uint8_t> &Result);
70 
71 private:
72  void EmitInt8(unsigned Opcode) {
73  Ops.push_back(Opcode & 0xff);
74  OpBegins.push_back(OpBegins.back() + 1);
75  }
76 
77  void EmitInt16(unsigned Opcode) {
78  Ops.push_back((Opcode >> 8) & 0xff);
79  Ops.push_back(Opcode & 0xff);
80  OpBegins.push_back(OpBegins.back() + 2);
81  }
82 
83  void EmitBytes(const uint8_t *Opcode, size_t Size) {
84  Ops.insert(Ops.end(), Opcode, Opcode + Size);
85  OpBegins.push_back(OpBegins.back() + Size);
86  }
87 };
88 
89 } // end namespace llvm
90 
91 #endif // LLVM_LIB_TARGET_ARM_MCTARGETDESC_ARMUNWINDOPASM_H
void EmitRaw(const SmallVectorImpl< uint8_t > &Opcodes)
Emit unwind raw opcodes.
This class represents lattice values for constants.
Definition: AllocatorList.h:23
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
void push_back(const T &Elt)
Definition: SmallVector.h:211
unsigned Reg
void Finalize(unsigned &PersonalityIndex, SmallVectorImpl< uint8_t > &Result)
Finalize the unwind opcode sequence for EmitBytes()
void Reset()
Reset the unwind opcode assembler.
size_t size() const
Definition: SmallVector.h:52
void EmitSPOffset(int64_t Offset)
Emit unwind opcodes to add $sp with an offset.
void EmitRegSave(uint32_t RegSave)
Emit unwind opcodes for .save directives.
iterator insert(iterator I, T &&Elt)
Definition: SmallVector.h:467
uint32_t Size
Definition: Profile.cpp:46
void EmitVFPRegSave(uint32_t VFPRegSave)
Emit unwind opcodes for .vsave directives.
void setPersonality(const MCSymbol *Per)
Set the personality.
void EmitSetSP(uint16_t Reg)
Emit unwind opcodes to copy address from source register to $sp.