llvm-project/lldb/source/Core/ConstString.cpp

343 lines
10 KiB
C++

//===-- 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/Core/ConstString.h"
#include "lldb/Core/Stream.h"
#include "lldb/Host/Mutex.h"
#include "llvm/ADT/StringMap.h"
using namespace lldb_private;
class Pool
{
public:
typedef const char * StringPoolValueType;
typedef llvm::StringMap<StringPoolValueType, llvm::BumpPtrAllocator> StringPool;
typedef llvm::StringMapEntry<StringPoolValueType> StringPoolEntryType;
//------------------------------------------------------------------
// Default constructor
//
// Initialize the member variables and create the empty string.
//------------------------------------------------------------------
Pool () :
m_mutex (Mutex::eMutexTypeRecursive),
m_string_map ()
{
}
//------------------------------------------------------------------
// Destructor
//------------------------------------------------------------------
~Pool ()
{
}
static StringPoolEntryType &
GetStringMapEntryFromKeyData (const char *keyData)
{
char *ptr = const_cast<char*>(keyData) - sizeof (StringPoolEntryType);
return *reinterpret_cast<StringPoolEntryType*>(ptr);
}
size_t
GetConstCStringLength (const char *ccstr) const
{
if (ccstr)
{
const StringPoolEntryType&entry = GetStringMapEntryFromKeyData (ccstr);
return entry.getKey().size();
}
return 0;
}
StringPoolValueType
GetMangledCounterpart (const char *ccstr) const
{
if (ccstr)
return GetStringMapEntryFromKeyData (ccstr).getValue();
return 0;
}
bool
SetMangledCounterparts (const char *key_ccstr, const char *value_ccstr)
{
if (key_ccstr && value_ccstr)
{
GetStringMapEntryFromKeyData (key_ccstr).setValue(value_ccstr);
GetStringMapEntryFromKeyData (value_ccstr).setValue(key_ccstr);
return true;
}
return false;
}
const char *
GetConstCString (const char *cstr)
{
if (cstr)
return GetConstCStringWithLength (cstr, strlen (cstr));
return NULL;
}
const char *
GetConstCStringWithLength (const char *cstr, size_t cstr_len)
{
if (cstr)
{
Mutex::Locker locker (m_mutex);
llvm::StringRef string_ref (cstr, cstr_len);
StringPoolEntryType& entry = m_string_map.GetOrCreateValue (string_ref, (StringPoolValueType)NULL);
return entry.getKeyData();
}
return NULL;
}
const char *
GetConstCStringWithStringRef (const llvm::StringRef &string_ref)
{
if (string_ref.data())
{
Mutex::Locker locker (m_mutex);
StringPoolEntryType& entry = m_string_map.GetOrCreateValue (string_ref, (StringPoolValueType)NULL);
return entry.getKeyData();
}
return NULL;
}
const char *
GetConstCStringAndSetMangledCounterPart (const char *demangled_cstr, const char *mangled_ccstr)
{
if (demangled_cstr)
{
Mutex::Locker locker (m_mutex);
// Make string pool entry with the mangled counterpart already set
StringPoolEntryType& entry = m_string_map.GetOrCreateValue (llvm::StringRef (demangled_cstr), mangled_ccstr);
// Extract the const version of the demangled_cstr
const char *demangled_ccstr = entry.getKeyData();
// Now assign the demangled const string as the counterpart of the
// mangled const string...
GetStringMapEntryFromKeyData (mangled_ccstr).setValue(demangled_ccstr);
// Return the constant demangled C string
return demangled_ccstr;
}
return NULL;
}
const char *
GetConstTrimmedCStringWithLength (const char *cstr, size_t cstr_len)
{
if (cstr)
{
const size_t trimmed_len = std::min<size_t> (strlen (cstr), cstr_len);
return GetConstCStringWithLength (cstr, trimmed_len);
}
return NULL;
}
//------------------------------------------------------------------
// 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
{
Mutex::Locker locker (m_mutex);
size_t mem_size = sizeof(Pool);
const_iterator end = m_string_map.end();
for (const_iterator pos = m_string_map.begin(); pos != end; ++pos)
{
mem_size += sizeof(StringPoolEntryType) + pos->getKey().size();
}
return mem_size;
}
protected:
//------------------------------------------------------------------
// Typedefs
//------------------------------------------------------------------
typedef StringPool::iterator iterator;
typedef StringPool::const_iterator const_iterator;
//------------------------------------------------------------------
// Member variables
//------------------------------------------------------------------
mutable Mutex m_mutex;
StringPool m_string_map;
};
//----------------------------------------------------------------------
// 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.
//
// FIXME: If we are going to keep it this way we should come up with some
// abstraction to "pthread_once" so we don't have to check the pointer
// every time.
//----------------------------------------------------------------------
static Pool &
StringPool()
{
static Mutex g_pool_initialization_mutex;
static Pool *g_string_pool = NULL;
if (g_string_pool == NULL)
{
Mutex::Locker initialization_locker(g_pool_initialization_mutex);
if (g_string_pool == NULL)
{
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 (m_string, StringPool().GetConstCStringLength (m_string));
llvm::StringRef rhs_string_ref (rhs.m_string, StringPool().GetConstCStringLength (rhs.m_string));
// 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 NULL, so if LHS is NULL then it is less than
return lhs_string_ref.data() == NULL;
}
Stream&
lldb_private::operator << (Stream& s, const ConstString& str)
{
const char *cstr = str.GetCString();
if (cstr)
s << cstr;
return s;
}
size_t
ConstString::GetLength () const
{
return StringPool().GetConstCStringLength (m_string);
}
int
ConstString::Compare (const ConstString& lhs, const ConstString& rhs)
{
// 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_cstr, StringPool().GetConstCStringLength (lhs_cstr));
llvm::StringRef rhs_string_ref (rhs_cstr, StringPool().GetConstCStringLength (rhs_cstr));
return lhs_string_ref.compare(rhs_string_ref);
}
if (lhs_cstr)
return +1; // LHS isn't NULL but RHS is
else
return -1; // LHS is NULL but RHS isn't
}
void
ConstString::Dump(Stream *s, const char *fail_value) const
{
if (s)
{
const char *cstr = AsCString (fail_value);
if (cstr)
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-NULL string
const char *parens = cstr ? "\"" : "";
s->Printf("%*p: ConstString, string = %s%s%s, length = %" PRIu64, (int)sizeof(void*) * 2, this, parens, cstr, parens, (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();
}