MCFunction.h revision 263508 
1//===-- llvm/MC/MCFunction.h ------------------------------------*- 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 defines the data structures to hold a CFG reconstructed from
11// machine code.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_MC_MCFUNCTION_H
16#define LLVM_MC_MCFUNCTION_H
17
18#include "llvm/ADT/StringRef.h"
19#include "llvm/MC/MCInst.h"
20#include <string>
21#include <vector>
22
23namespace llvm {
24
25class MCFunction;
26class MCModule;
27class MCTextAtom;
28
29/// \brief Basic block containing a sequence of disassembled instructions.
30/// The basic block is backed by an MCTextAtom, which holds the instructions,
31/// and the address range it covers.
32/// Create a basic block using MCFunction::createBlock.
33class MCBasicBlock {
34  const MCTextAtom *Insts;
35
36  // MCFunction owns the basic block.
37  MCFunction *Parent;
38  friend class MCFunction;
39  MCBasicBlock(const MCTextAtom &Insts, MCFunction *Parent);
40
41  /// \name Predecessors/Successors, to represent the CFG.
42  /// @{
43  typedef std::vector<const MCBasicBlock *> BasicBlockListTy;
44  BasicBlockListTy Successors;
45  BasicBlockListTy Predecessors;
46  /// @}
47public:
48
49  /// \brief Get the backing MCTextAtom, containing the instruction sequence.
50  const MCTextAtom *getInsts() const { return Insts; }
51
52  /// \name Get the owning MCFunction.
53  /// @{
54  const MCFunction *getParent() const { return Parent; }
55        MCFunction *getParent()       { return Parent; }
56  /// @}
57
58  /// MC CFG access: Predecessors/Successors.
59  /// @{
60  typedef BasicBlockListTy::const_iterator succ_const_iterator;
61  succ_const_iterator succ_begin() const { return Successors.begin(); }
62  succ_const_iterator succ_end()   const { return Successors.end(); }
63
64  typedef BasicBlockListTy::const_iterator pred_const_iterator;
65  pred_const_iterator pred_begin() const { return Predecessors.begin(); }
66  pred_const_iterator pred_end()   const { return Predecessors.end(); }
67
68  void addSuccessor(const MCBasicBlock *MCBB);
69  bool isSuccessor(const MCBasicBlock *MCBB) const;
70
71  void addPredecessor(const MCBasicBlock *MCBB);
72  bool isPredecessor(const MCBasicBlock *MCBB) const;
73
74  /// \brief Split block, mirrorring NewAtom = Insts->split(..).
75  /// This moves all successors to \p SplitBB, and
76  /// adds a fallthrough to it.
77  /// \p SplitBB The result of splitting Insts, a basic block directly following
78  /// this basic block.
79  void splitBasicBlock(MCBasicBlock *SplitBB);
80  /// @}
81};
82
83/// \brief Represents a function in machine code, containing MCBasicBlocks.
84/// MCFunctions are created by MCModule.
85class MCFunction {
86  MCFunction           (const MCFunction&) LLVM_DELETED_FUNCTION;
87  MCFunction& operator=(const MCFunction&) LLVM_DELETED_FUNCTION;
88
89  std::string Name;
90  MCModule *ParentModule;
91  typedef std::vector<MCBasicBlock*> BasicBlockListTy;
92  BasicBlockListTy Blocks;
93
94  // MCModule owns the function.
95  friend class MCModule;
96  MCFunction(StringRef Name, MCModule *Parent);
97  ~MCFunction();
98
99public:
100  /// \brief Create an MCBasicBlock backed by Insts and add it to this function.
101  /// \param Insts Sequence of straight-line code backing the basic block.
102  /// \returns The newly created basic block.
103  MCBasicBlock &createBlock(const MCTextAtom &Insts);
104
105  StringRef getName() const { return Name; }
106
107  /// \name Get the owning MC Module.
108  /// @{
109  const MCModule *getParent() const { return ParentModule; }
110        MCModule *getParent()       { return ParentModule; }
111  /// @}
112
113  /// \name Access to the function's basic blocks. No ordering is enforced,
114  /// except that the first block is the entry block.
115  /// @{
116  /// \brief Get the entry point basic block.
117  const MCBasicBlock *getEntryBlock() const { return front(); }
118        MCBasicBlock *getEntryBlock()       { return front(); }
119
120  bool empty() const { return Blocks.empty(); }
121
122  typedef BasicBlockListTy::const_iterator const_iterator;
123  typedef BasicBlockListTy::      iterator       iterator;
124  const_iterator begin() const { return Blocks.begin(); }
125        iterator begin()       { return Blocks.begin(); }
126  const_iterator   end() const { return Blocks.end(); }
127        iterator   end()       { return Blocks.end(); }
128
129  const MCBasicBlock* front() const { return Blocks.front(); }
130        MCBasicBlock* front()       { return Blocks.front(); }
131  const MCBasicBlock*  back() const { return Blocks.back(); }
132        MCBasicBlock*  back()       { return Blocks.back(); }
133
134  /// \brief Find the basic block, if any, that starts at \p StartAddr.
135  const MCBasicBlock *find(uint64_t StartAddr) const;
136        MCBasicBlock *find(uint64_t StartAddr);
137  /// @}
138};
139
140}
141
142#endif
143