teak-llvm/lldb/source/Interpreter/CommandHistory.cpp
Kate Stone 0167e064f3 Addresses an unsigned underflow situation that can occur when dumping an empty command history.
One example where this occurs in practice is starting the Swift REPL and typing ":command history" since REPL commands aren't stored in the LLDB command prompt history.

llvm-svn: 256888
2016-01-06 00:33:07 +00:00

146 lines
3.2 KiB
C++

//===-- CommandHistory.cpp --------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include <inttypes.h>
#include "lldb/Interpreter/CommandHistory.h"
#include "lldb/Host/StringConvert.h"
using namespace lldb;
using namespace lldb_private;
CommandHistory::CommandHistory () :
m_mutex(Mutex::eMutexTypeRecursive),
m_history()
{}
CommandHistory::~CommandHistory ()
{}
size_t
CommandHistory::GetSize () const
{
Mutex::Locker locker(m_mutex);
return m_history.size();
}
bool
CommandHistory::IsEmpty () const
{
Mutex::Locker locker(m_mutex);
return m_history.empty();
}
const char*
CommandHistory::FindString (const char* input_str) const
{
Mutex::Locker locker(m_mutex);
if (!input_str)
return nullptr;
if (input_str[0] != g_repeat_char)
return nullptr;
if (input_str[1] == '-')
{
bool success;
size_t idx = StringConvert::ToUInt32 (input_str+2, 0, 0, &success);
if (!success)
return nullptr;
if (idx > m_history.size())
return nullptr;
idx = m_history.size() - idx;
return m_history[idx].c_str();
}
else if (input_str[1] == g_repeat_char)
{
if (m_history.empty())
return nullptr;
else
return m_history.back().c_str();
}
else
{
bool success;
uint32_t idx = StringConvert::ToUInt32 (input_str+1, 0, 0, &success);
if (!success)
return nullptr;
if (idx >= m_history.size())
return nullptr;
return m_history[idx].c_str();
}
}
const char*
CommandHistory::GetStringAtIndex (size_t idx) const
{
Mutex::Locker locker(m_mutex);
if (idx < m_history.size())
return m_history[idx].c_str();
return nullptr;
}
const char*
CommandHistory::operator [] (size_t idx) const
{
return GetStringAtIndex(idx);
}
const char*
CommandHistory::GetRecentmostString () const
{
Mutex::Locker locker(m_mutex);
if (m_history.empty())
return nullptr;
return m_history.back().c_str();
}
void
CommandHistory::AppendString (const std::string& str,
bool reject_if_dupe)
{
Mutex::Locker locker(m_mutex);
if (reject_if_dupe)
{
if (!m_history.empty())
{
if (str == m_history.back())
return;
}
}
m_history.push_back(std::string(str));
}
void
CommandHistory::Clear ()
{
Mutex::Locker locker(m_mutex);
m_history.clear();
}
void
CommandHistory::Dump (Stream& stream,
size_t start_idx,
size_t stop_idx) const
{
Mutex::Locker locker(m_mutex);
stop_idx = std::min(stop_idx + 1, m_history.size());
for (size_t counter = start_idx;
counter < stop_idx;
counter++)
{
const std::string hist_item = m_history[counter];
if (!hist_item.empty())
{
stream.Indent();
stream.Printf("%4" PRIu64 ": %s\n", (uint64_t)counter, hist_item.c_str());
}
}
}