1 //===-- StringTableBuilder.h - String table building utility ------*- 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 #ifndef LLVM_MC_STRINGTABLEBUILDER_H
11 #define LLVM_MC_STRINGTABLEBUILDER_H
12 
13 #include "llvm/ADT/SmallString.h"
14 #include "llvm/ADT/DenseMap.h"
15 #include <cassert>
16 
17 namespace llvm {
18 
19 /// \brief Utility for building string tables with deduplicated suffixes.
20 class StringTableBuilder {
21 public:
22   enum Kind { ELF, WinCOFF, MachO, RAW };
23 
24 private:
25   SmallString<256> StringTable;
26   DenseMap<StringRef, size_t> StringIndexMap;
27   size_t Size = 0;
28   Kind K;
29 
30 public:
31   StringTableBuilder(Kind K);
32 
33   /// \brief Add a string to the builder. Returns the position of S in the
34   /// table. The position will be changed if finalize is used.
35   /// Can only be used before the table is finalized.
36   size_t add(StringRef S);
37 
38   /// \brief Analyze the strings and build the final table. No more strings can
39   /// be added after this point.
40   void finalize();
41 
42   /// \brief Retrieve the string table data. Can only be used after the table
43   /// is finalized.
data()44   StringRef data() const {
45     assert(isFinalized());
46     return StringTable;
47   }
48 
49   /// \brief Get the offest of a string in the string table. Can only be used
50   /// after the table is finalized.
51   size_t getOffset(StringRef S) const;
52 
getMap()53   const DenseMap<StringRef, size_t> &getMap() const { return StringIndexMap; }
getSize()54   size_t getSize() const { return Size; }
55   void clear();
56 
57 private:
isFinalized()58   bool isFinalized() const {
59     return !StringTable.empty();
60   }
61 };
62 
63 } // end llvm namespace
64 
65 #endif
66