Line data    Source code

       1             : //===- llvm/Support/StringSaver.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             : #ifndef LLVM_SUPPORT_STRINGSAVER_H
      11             : #define LLVM_SUPPORT_STRINGSAVER_H
      12             : 
      13             : #include "llvm/ADT/DenseSet.h"
      14             : #include "llvm/ADT/StringRef.h"
      15             : #include "llvm/ADT/Twine.h"
      16             : #include "llvm/Support/Allocator.h"
      17             : 
      18             : namespace llvm {
      19             : 
      20             : /// Saves strings in the provided stable storage and returns a
      21             : /// StringRef with a stable character pointer.
      22             : class StringSaver final {
      23             :   BumpPtrAllocator &Alloc;
      24             : 
      25             : public:
      26      222506 :   StringSaver(BumpPtrAllocator &Alloc) : Alloc(Alloc) {}
      27             : 
      28             :   // All returned strings are null-terminated: *save(S).end() == 0.
      29          88 :   StringRef save(const char *S) { return save(StringRef(S)); }
      30             :   StringRef save(StringRef S);
      31      524749 :   StringRef save(const Twine &S) { return save(StringRef(S.str())); }
      32       45241 :   StringRef save(const std::string &S) { return save(StringRef(S)); }
      33             : };
      34             : 
      35             : /// Saves strings in the provided stable storage and returns a StringRef with a
      36             : /// stable character pointer. Saving the same string yields the same StringRef.
      37             : ///
      38             : /// Compared to StringSaver, it does more work but avoids saving the same string
      39             : /// multiple times.
      40             : ///
      41             : /// Compared to StringPool, it performs fewer allocations but doesn't support
      42             : /// refcounting/deletion.
      43          73 : class UniqueStringSaver final {
      44             :   StringSaver Strings;
      45             :   llvm::DenseSet<llvm::StringRef> Unique;
      46             : 
      47             : public:
      48         155 :   UniqueStringSaver(BumpPtrAllocator &Alloc) : Strings(Alloc) {}
      49             : 
      50             :   // All returned strings are null-terminated: *save(S).end() == 0.
      51             :   StringRef save(const char *S) { return save(StringRef(S)); }
      52             :   StringRef save(StringRef S);
      53             :   StringRef save(const Twine &S) { return save(StringRef(S.str())); }
      54             :   StringRef save(const std::string &S) { return save(StringRef(S)); }
      55             : };
      56             : 
      57             : }
      58             : #endif