MCFunction.h revision cd81d94322a39503e4a3e87b6ee03d4fcb3465fb 
1//===-- 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_MCANALYSIS_MCFUNCTION_H
16#define LLVM_MC_MCANALYSIS_MCFUNCTION_H
17
18#include "llvm/ADT/StringRef.h"
19#include "llvm/MC/MCInst.h"
20#include <memory>
21#include <string>
22#include <vector>
23
24namespace llvm {
25
26class MCFunction;
27class MCModule;
28class MCTextAtom;
29
30/// \brief Basic block containing a sequence of disassembled instructions.
31/// The basic block is backed by an MCTextAtom, which holds the instructions,
32/// and the address range it covers.
33/// Create a basic block using MCFunction::createBlock.
34class MCBasicBlock {
35  const MCTextAtom *Insts;
36
37  // MCFunction owns the basic block.
38  MCFunction *Parent;
39  friend class MCFunction;
40  MCBasicBlock(const MCTextAtom &Insts, MCFunction *Parent);
41
42  /// \name Predecessors/Successors, to represent the CFG.
43  /// @{
44  typedef std::vector<const MCBasicBlock *> BasicBlockListTy;
45  BasicBlockListTy Successors;
46  BasicBlockListTy Predecessors;
47  /// @}
48public:
49
50  /// \brief Get the backing MCTextAtom, containing the instruction sequence.
51  const MCTextAtom *getInsts() const { return Insts; }
52
53  /// \name Get the owning MCFunction.
54  /// @{
55  const MCFunction *getParent() const { return Parent; }
56        MCFunction *getParent()       { return Parent; }
57  /// @}
58
59  /// MC CFG access: Predecessors/Successors.
60  /// @{
61  typedef BasicBlockListTy::const_iterator succ_const_iterator;
62  succ_const_iterator succ_begin() const { return Successors.begin(); }
63  succ_const_iterator succ_end()   const { return Successors.end(); }
64
65  typedef BasicBlockListTy::const_iterator pred_const_iterator;
66  pred_const_iterator pred_begin() const { return Predecessors.begin(); }
67  pred_const_iterator pred_end()   const { return Predecessors.end(); }
68
69  void addSuccessor(const MCBasicBlock *MCBB);
70  bool isSuccessor(const MCBasicBlock *MCBB) const;
71
72  void addPredecessor(const MCBasicBlock *MCBB);
73  bool isPredecessor(const MCBasicBlock *MCBB) const;
74
75  /// \brief Split block, mirrorring NewAtom = Insts->split(..).
76  /// This moves all successors to \p SplitBB, and
77  /// adds a fallthrough to it.
78  /// \p SplitBB The result of splitting Insts, a basic block directly following
79  /// this basic block.
80  void splitBasicBlock(MCBasicBlock *SplitBB);
81  /// @}
82};
83
84/// \brief Represents a function in machine code, containing MCBasicBlocks.
85/// MCFunctions are created by MCModule.
86class MCFunction {
87  MCFunction           (const MCFunction&) LLVM_DELETED_FUNCTION;
88  MCFunction& operator=(const MCFunction&) LLVM_DELETED_FUNCTION;
89
90  std::string Name;
91  MCModule *ParentModule;
92  typedef std::vector<std::unique_ptr<MCBasicBlock>> BasicBlockListTy;
93  BasicBlockListTy Blocks;
94
95  // MCModule owns the function.
96  friend class MCModule;
97  MCFunction(StringRef Name, MCModule *Parent);
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().get(); }
130        MCBasicBlock* front()       { return Blocks.front().get(); }
131  const MCBasicBlock*  back() const { return Blocks.back().get(); }
132        MCBasicBlock*  back()       { return Blocks.back().get(); }
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