1 files changed, 340 insertions, 0 deletions
diff --git a/contrib/llvm/tools/lldb/source/Utility/ConstString.cpp b/contrib/llvm/tools/lldb/source/Utility/ConstString.cpp
new file mode 100644
index 0000000..49cf8a6
--- /dev/null
+++ b/contrib/llvm/tools/lldb/source/Utility/ConstString.cpp
@@ -0,0 +1,340 @@
+//===-- ConstString.cpp -----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Utility/ConstString.h"
+
+#include "lldb/Utility/Stream.h"
+
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/iterator.h"            // for iterator_facade_base
+#include "llvm/Support/Allocator.h"       // for BumpPtrAllocator
+#include "llvm/Support/FormatProviders.h" // for format_provider
+#include "llvm/Support/RWMutex.h"
+#include "llvm/Support/Threading.h"
+
+#include <algorithm> // for min
+#include <array>
+#include <utility> // for make_pair, pair
+
+#include <inttypes.h> // for PRIu64
+#include <stdint.h>   // for uint8_t, uint32_t, uint64_t
+#include <string.h>   // for size_t, strlen
+
+using namespace lldb_private;
+
+class Pool {
+public:
+  typedef const char *StringPoolValueType;
+  typedef llvm::StringMap<StringPoolValueType, llvm::BumpPtrAllocator>
+      StringPool;
+  typedef llvm::StringMapEntry<StringPoolValueType> StringPoolEntryType;
+
+  static StringPoolEntryType &
+  GetStringMapEntryFromKeyData(const char *keyData) {
+    return StringPoolEntryType::GetStringMapEntryFromKeyData(keyData);
+  }
+
+  static size_t GetConstCStringLength(const char *ccstr) {
+    if (ccstr != nullptr) {
+      // Since the entry is read only, and we derive the entry entirely from the
+      // pointer, we don't need the lock.
+      const StringPoolEntryType &entry = GetStringMapEntryFromKeyData(ccstr);
+      return entry.getKey().size();
+    }
+    return 0;
+  }
+
+  StringPoolValueType GetMangledCounterpart(const char *ccstr) const {
+    if (ccstr != nullptr) {
+      const uint8_t h = hash(llvm::StringRef(ccstr));
+      llvm::sys::SmartScopedReader<false> rlock(m_string_pools[h].m_mutex);
+      return GetStringMapEntryFromKeyData(ccstr).getValue();
+    }
+    return nullptr;
+  }
+
+  bool SetMangledCounterparts(const char *key_ccstr, const char *value_ccstr) {
+    if (key_ccstr != nullptr && value_ccstr != nullptr) {
+      {
+        const uint8_t h = hash(llvm::StringRef(key_ccstr));
+        llvm::sys::SmartScopedWriter<false> wlock(m_string_pools[h].m_mutex);
+        GetStringMapEntryFromKeyData(key_ccstr).setValue(value_ccstr);
+      }
+      {
+        const uint8_t h = hash(llvm::StringRef(value_ccstr));
+        llvm::sys::SmartScopedWriter<false> wlock(m_string_pools[h].m_mutex);
+        GetStringMapEntryFromKeyData(value_ccstr).setValue(key_ccstr);
+      }
+      return true;
+    }
+    return false;
+  }
+
+  const char *GetConstCString(const char *cstr) {
+    if (cstr != nullptr)
+      return GetConstCStringWithLength(cstr, strlen(cstr));
+    return nullptr;
+  }
+
+  const char *GetConstCStringWithLength(const char *cstr, size_t cstr_len) {
+    if (cstr != nullptr)
+      return GetConstCStringWithStringRef(llvm::StringRef(cstr, cstr_len));
+    return nullptr;
+  }
+
+  const char *GetConstCStringWithStringRef(const llvm::StringRef &string_ref) {
+    if (string_ref.data()) {
+      const uint8_t h = hash(string_ref);
+
+      {
+        llvm::sys::SmartScopedReader<false> rlock(m_string_pools[h].m_mutex);
+        auto it = m_string_pools[h].m_string_map.find(string_ref);
+        if (it != m_string_pools[h].m_string_map.end())
+          return it->getKeyData();
+      }
+
+      llvm::sys::SmartScopedWriter<false> wlock(m_string_pools[h].m_mutex);
+      StringPoolEntryType &entry =
+          *m_string_pools[h]
+               .m_string_map.insert(std::make_pair(string_ref, nullptr))
+               .first;
+      return entry.getKeyData();
+    }
+    return nullptr;
+  }
+
+  const char *
+  GetConstCStringAndSetMangledCounterPart(const char *demangled_cstr,
+                                          const char *mangled_ccstr) {
+    if (demangled_cstr != nullptr) {
+      const char *demangled_ccstr = nullptr;
+
+      {
+        llvm::StringRef string_ref(demangled_cstr);
+        const uint8_t h = hash(string_ref);
+        llvm::sys::SmartScopedWriter<false> wlock(m_string_pools[h].m_mutex);
+
+        // Make string pool entry with the mangled counterpart already set
+        StringPoolEntryType &entry =
+            *m_string_pools[h]
+                 .m_string_map.insert(std::make_pair(string_ref, mangled_ccstr))
+                 .first;
+
+        // Extract the const version of the demangled_cstr
+        demangled_ccstr = entry.getKeyData();
+      }
+
+      {
+        // Now assign the demangled const string as the counterpart of the
+        // mangled const string...
+        const uint8_t h = hash(llvm::StringRef(mangled_ccstr));
+        llvm::sys::SmartScopedWriter<false> wlock(m_string_pools[h].m_mutex);
+        GetStringMapEntryFromKeyData(mangled_ccstr).setValue(demangled_ccstr);
+      }
+
+      // Return the constant demangled C string
+      return demangled_ccstr;
+    }
+    return nullptr;
+  }
+
+  const char *GetConstTrimmedCStringWithLength(const char *cstr,
+                                               size_t cstr_len) {
+    if (cstr != nullptr) {
+      const size_t trimmed_len = std::min<size_t>(strlen(cstr), cstr_len);
+      return GetConstCStringWithLength(cstr, trimmed_len);
+    }
+    return nullptr;
+  }
+
+  //------------------------------------------------------------------
+  // Return the size in bytes that this object and any items in its
+  // collection of uniqued strings + data count values takes in
+  // memory.
+  //------------------------------------------------------------------
+  size_t MemorySize() const {
+    size_t mem_size = sizeof(Pool);
+    for (const auto &pool : m_string_pools) {
+      llvm::sys::SmartScopedReader<false> rlock(pool.m_mutex);
+      for (const auto &entry : pool.m_string_map)
+        mem_size += sizeof(StringPoolEntryType) + entry.getKey().size();
+    }
+    return mem_size;
+  }
+
+protected:
+  uint8_t hash(const llvm::StringRef &s) const {
+    uint32_t h = llvm::HashString(s);
+    return ((h >> 24) ^ (h >> 16) ^ (h >> 8) ^ h) & 0xff;
+  }
+
+  struct PoolEntry {
+    mutable llvm::sys::SmartRWMutex<false> m_mutex;
+    StringPool m_string_map;
+  };
+
+  std::array<PoolEntry, 256> m_string_pools;
+};
+
+//----------------------------------------------------------------------
+// Frameworks and dylibs aren't supposed to have global C++
+// initializers so we hide the string pool in a static function so
+// that it will get initialized on the first call to this static
+// function.
+//
+// Note, for now we make the string pool a pointer to the pool, because
+// we can't guarantee that some objects won't get destroyed after the
+// global destructor chain is run, and trying to make sure no destructors
+// touch ConstStrings is difficult.  So we leak the pool instead.
+//----------------------------------------------------------------------
+static Pool &StringPool() {
+  static llvm::once_flag g_pool_initialization_flag;
+  static Pool *g_string_pool = nullptr;
+
+  llvm::call_once(g_pool_initialization_flag,
+                 []() { g_string_pool = new Pool(); });
+
+  return *g_string_pool;
+}
+
+ConstString::ConstString(const char *cstr)
+    : m_string(StringPool().GetConstCString(cstr)) {}
+
+ConstString::ConstString(const char *cstr, size_t cstr_len)
+    : m_string(StringPool().GetConstCStringWithLength(cstr, cstr_len)) {}
+
+ConstString::ConstString(const llvm::StringRef &s)
+    : m_string(StringPool().GetConstCStringWithLength(s.data(), s.size())) {}
+
+bool ConstString::operator<(const ConstString &rhs) const {
+  if (m_string == rhs.m_string)
+    return false;
+
+  llvm::StringRef lhs_string_ref(GetStringRef());
+  llvm::StringRef rhs_string_ref(rhs.GetStringRef());
+
+  // If both have valid C strings, then return the comparison
+  if (lhs_string_ref.data() && rhs_string_ref.data())
+    return lhs_string_ref < rhs_string_ref;
+
+  // Else one of them was nullptr, so if LHS is nullptr then it is less than
+  return lhs_string_ref.data() == nullptr;
+}
+
+Stream &lldb_private::operator<<(Stream &s, const ConstString &str) {
+  const char *cstr = str.GetCString();
+  if (cstr != nullptr)
+    s << cstr;
+
+  return s;
+}
+
+size_t ConstString::GetLength() const {
+  return Pool::GetConstCStringLength(m_string);
+}
+
+bool ConstString::Equals(const ConstString &lhs, const ConstString &rhs,
+                         const bool case_sensitive) {
+  if (lhs.m_string == rhs.m_string)
+    return true;
+
+  // Since the pointers weren't equal, and identical ConstStrings always have
+  // identical pointers,
+  // the result must be false for case sensitive equality test.
+  if (case_sensitive)
+    return false;
+
+  // perform case insensitive equality test
+  llvm::StringRef lhs_string_ref(lhs.GetStringRef());
+  llvm::StringRef rhs_string_ref(rhs.GetStringRef());
+  return lhs_string_ref.equals_lower(rhs_string_ref);
+}
+
+int ConstString::Compare(const ConstString &lhs, const ConstString &rhs,
+                         const bool case_sensitive) {
+  // If the iterators are the same, this is the same string
+  const char *lhs_cstr = lhs.m_string;
+  const char *rhs_cstr = rhs.m_string;
+  if (lhs_cstr == rhs_cstr)
+    return 0;
+  if (lhs_cstr && rhs_cstr) {
+    llvm::StringRef lhs_string_ref(lhs.GetStringRef());
+    llvm::StringRef rhs_string_ref(rhs.GetStringRef());
+
+    if (case_sensitive) {
+      return lhs_string_ref.compare(rhs_string_ref);
+    } else {
+      return lhs_string_ref.compare_lower(rhs_string_ref);
+    }
+  }
+
+  if (lhs_cstr)
+    return +1; // LHS isn't nullptr but RHS is
+  else
+    return -1; // LHS is nullptr but RHS isn't
+}
+
+void ConstString::Dump(Stream *s, const char *fail_value) const {
+  if (s != nullptr) {
+    const char *cstr = AsCString(fail_value);
+    if (cstr != nullptr)
+      s->PutCString(cstr);
+  }
+}
+
+void ConstString::DumpDebug(Stream *s) const {
+  const char *cstr = GetCString();
+  size_t cstr_len = GetLength();
+  // Only print the parens if we have a non-nullptr string
+  const char *parens = cstr ? "\"" : "";
+  s->Printf("%*p: ConstString, string = %s%s%s, length = %" PRIu64,
+            static_cast<int>(sizeof(void *) * 2),
+            static_cast<const void *>(this), parens, cstr, parens,
+            static_cast<uint64_t>(cstr_len));
+}
+
+void ConstString::SetCString(const char *cstr) {
+  m_string = StringPool().GetConstCString(cstr);
+}
+
+void ConstString::SetString(const llvm::StringRef &s) {
+  m_string = StringPool().GetConstCStringWithLength(s.data(), s.size());
+}
+
+void ConstString::SetCStringWithMangledCounterpart(const char *demangled,
+                                                   const ConstString &mangled) {
+  m_string = StringPool().GetConstCStringAndSetMangledCounterPart(
+      demangled, mangled.m_string);
+}
+
+bool ConstString::GetMangledCounterpart(ConstString &counterpart) const {
+  counterpart.m_string = StringPool().GetMangledCounterpart(m_string);
+  return (bool)counterpart;
+}
+
+void ConstString::SetCStringWithLength(const char *cstr, size_t cstr_len) {
+  m_string = StringPool().GetConstCStringWithLength(cstr, cstr_len);
+}
+
+void ConstString::SetTrimmedCStringWithLength(const char *cstr,
+                                              size_t cstr_len) {
+  m_string = StringPool().GetConstTrimmedCStringWithLength(cstr, cstr_len);
+}
+
+size_t ConstString::StaticMemorySize() {
+  // Get the size of the static string pool
+  return StringPool().MemorySize();
+}
+
+void llvm::format_provider<ConstString>::format(const ConstString &CS,
+                                                llvm::raw_ostream &OS,
+                                                llvm::StringRef Options) {
+  format_provider<StringRef>::format(CS.AsCString(), OS, Options);
+}