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/StringMap.h"
15 #include <cassert>
16 
17 namespace llvm {
18 
19 /// \brief Utility for building string tables with deduplicated suffixes.
20 class StringTableBuilder {
21   SmallString<256> StringTable;
22   StringMap<size_t> StringIndexMap;
23 
24 public:
25   /// \brief Add a string to the builder. Returns a StringRef to the internal
26   /// copy of s. Can only be used before the table is finalized.
add(StringRef s)27   StringRef add(StringRef s) {
28     assert(!isFinalized());
29     return StringIndexMap.insert(std::make_pair(s, 0)).first->first();
30   }
31 
32   enum Kind {
33     ELF,
34     WinCOFF,
35     MachO
36   };
37 
38   /// \brief Analyze the strings and build the final table. No more strings can
39   /// be added after this point.
40   void finalize(Kind kind);
41 
42   /// \brief Retrieve the string table data. Can only be used after the table
43   /// is finalized.
data()44   StringRef data() {
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.
getOffset(StringRef s)51   size_t getOffset(StringRef s) {
52     assert(isFinalized());
53     assert(StringIndexMap.count(s) && "String is not in table!");
54     return StringIndexMap[s];
55   }
56 
57   void clear();
58 
59 private:
isFinalized()60   bool isFinalized() {
61     return !StringTable.empty();
62   }
63 };
64 
65 } // end llvm namespace
66 
67 #endif
68