1#ifndef TOOLS_LLVM_DWP_DWPSTRINGPOOL
2#define TOOLS_LLVM_DWP_DWPSTRINGPOOL
3
4#include "llvm/ADT/DenseMap.h"
5#include "llvm/MC/MCSection.h"
6#include "llvm/MC/MCStreamer.h"
7#include <cassert>
8
9namespace llvm {
10class DWPStringPool {
11
12  struct CStrDenseMapInfo {
13    static inline const char *getEmptyKey() {
14      return reinterpret_cast<const char *>(~static_cast<uintptr_t>(0));
15    }
16    static inline const char *getTombstoneKey() {
17      return reinterpret_cast<const char *>(~static_cast<uintptr_t>(1));
18    }
19    static unsigned getHashValue(const char *Val) {
20      assert(Val != getEmptyKey() && "Cannot hash the empty key!");
21      assert(Val != getTombstoneKey() && "Cannot hash the tombstone key!");
22      return (unsigned)hash_value(StringRef(Val));
23    }
24    static bool isEqual(const char *LHS, const char *RHS) {
25      if (RHS == getEmptyKey())
26        return LHS == getEmptyKey();
27      if (RHS == getTombstoneKey())
28        return LHS == getTombstoneKey();
29      return strcmp(LHS, RHS) == 0;
30    }
31  };
32
33  MCStreamer &Out;
34  MCSection *Sec;
35  DenseMap<const char *, uint32_t, CStrDenseMapInfo> Pool;
36  uint32_t Offset = 0;
37
38public:
39  DWPStringPool(MCStreamer &Out, MCSection *Sec) : Out(Out), Sec(Sec) {}
40
41  uint32_t getOffset(const char *Str, unsigned Length) {
42    assert(strlen(Str) + 1 == Length && "Ensure length hint is correct");
43
44    auto Pair = Pool.insert(std::make_pair(Str, Offset));
45    if (Pair.second) {
46      Out.SwitchSection(Sec);
47      Out.EmitBytes(StringRef(Str, Length));
48      Offset += Length;
49    }
50
51    return Pair.first->second;
52  }
53};
54}
55
56#endif
57