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 9 namespace llvm { 10 class 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 38 public: 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
