[lldb] NFC modernize codebase with modernize-use-nullptr

Summary:
NFC = [[ https://llvm.org/docs/Lexicon.html#nfc | Non functional change ]]

This commit is the result of modernizing the LLDB codebase by using
`nullptr` instread of `0` or `NULL`. See
https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-nullptr.html
for more information.

This is the command I ran and I to fix and format the code base:

```
run-clang-tidy.py \
	-header-filter='.*' \
	-checks='-*,modernize-use-nullptr' \
	-fix ~/dev/llvm-project/lldb/.* \
	-format \
	-style LLVM \
	-p ~/llvm-builds/debug-ninja-gcc
```

NOTE: There were also changes to `llvm/utils/unittest` but I did not
include them because I felt that maybe this library shall be updated in
isolation somehow.

NOTE: I know this is a rather large commit but it is a nobrainer in most
parts.

Reviewers: martong, espindola, shafik, #lldb, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: arsenm, jvesely, nhaehnle, hiraditya, JDevlieghere, teemperor, rnkovacs, emaste, kubamracek, nemanjai, ki.stfu, javed.absar, arichardson, kbarton, jrtc27, MaskRay, atanasyan, dexonsmith, arphaman, jfb, jsji, jdoerfert, lldb-commits, llvm-commits

Tags: #lldb, #llvm

Differential Revision: https://reviews.llvm.org/D61847

llvm-svn: 361484

16 files changed, 43 insertions, 40 deletions

diff --git a/lldb/source/Host/common/Editline.cpp b/lldb/source/Host/common/Editline.cpp
index 2b647be572a..d3a70aeaa32 100644
--- a/lldb/source/Host/common/Editline.cpp
+++ b/lldb/source/Host/common/Editline.cpp
@@ -163,7 +163,7 @@ private:
   // Use static GetHistory() function to get a EditlineHistorySP to one of
   // these objects
   EditlineHistory(const std::string &prefix, uint32_t size, bool unique_entries)
-      : m_history(NULL), m_event(), m_prefix(prefix), m_path() {
+      : m_history(nullptr), m_event(), m_prefix(prefix), m_path() {
     m_history = history_winit();
     history_w(m_history, &m_event, H_SETSIZE, size);
     if (unique_entries)
@@ -202,7 +202,7 @@ public:
 
     if (m_history) {
       history_wend(m_history);
-      m_history = NULL;
+      m_history = nullptr;
     }
   }
 
@@ -224,7 +224,7 @@ public:
     return history_sp;
   }
 
-  bool IsValid() const { return m_history != NULL; }
+  bool IsValid() const { return m_history != nullptr; }
 
   HistoryW *GetHistoryPtr() { return m_history; }
 
@@ -514,11 +514,13 @@ int Editline::GetCharacter(EditLineGetCharType *c) {
     // Read returns, immediately lock the mutex again and check if we were
     // interrupted.
     m_output_mutex.unlock();
-    int read_count = m_input_connection.Read(&ch, 1, llvm::None, status, NULL);
+    int read_count =
+        m_input_connection.Read(&ch, 1, llvm::None, status, nullptr);
     m_output_mutex.lock();
     if (m_editor_status == EditorStatus::Interrupted) {
       while (read_count > 0 && status == lldb::eConnectionStatusSuccess)
-        read_count = m_input_connection.Read(&ch, 1, llvm::None, status, NULL);
+        read_count =
+            m_input_connection.Read(&ch, 1, llvm::None, status, nullptr);
       lldbassert(status == lldb::eConnectionStatusInterrupted);
       return 0;
     }
@@ -1081,7 +1083,7 @@ void Editline::ConfigureEditor(bool multiline) {
 
   // Allow user-specific customization prior to registering bindings we
   // absolutely require
-  el_source(m_editline, NULL);
+  el_source(m_editline, nullptr);
 
   // Register an internal binding that external developers shouldn't use
   el_wset(m_editline, EL_ADDFN, EditLineConstString("lldb-revert-line"),
diff --git a/lldb/source/Host/common/File.cpp b/lldb/source/Host/common/File.cpp
index 85e625ca78f..c8c8d7a0d49 100644
--- a/lldb/source/Host/common/File.cpp
+++ b/lldb/source/Host/common/File.cpp
@@ -65,11 +65,11 @@ static const char *GetStreamOpenModeFromOptions(uint32_t options) {
   } else if (options & File::eOpenOptionWrite) {
     return "w";
   }
-  return NULL;
+  return nullptr;
 }
 
 int File::kInvalidDescriptor = -1;
-FILE *File::kInvalidStream = NULL;
+FILE *File::kInvalidStream = nullptr;
 
 File::~File() { Close(); }
 
@@ -634,9 +634,9 @@ size_t File::Printf(const char *format, ...) {
 size_t File::PrintfVarArg(const char *format, va_list args) {
   size_t result = 0;
   if (DescriptorIsValid()) {
-    char *s = NULL;
+    char *s = nullptr;
     result = vasprintf(&s, format, args);
-    if (s != NULL) {
+    if (s != nullptr) {
       if (result > 0) {
         size_t s_len = result;
         Write(s, s_len);
diff --git a/lldb/source/Host/common/Host.cpp b/lldb/source/Host/common/Host.cpp
index d3e41a2b044..be206406e93 100644
--- a/lldb/source/Host/common/Host.cpp
+++ b/lldb/source/Host/common/Host.cpp
@@ -112,7 +112,7 @@ HostThread Host::StartMonitoringChildProcess(
   ::snprintf(thread_name, sizeof(thread_name),
              "<lldb.host.wait4(pid=%" PRIu64 ")>", pid);
   return ThreadLauncher::LaunchThread(
-      thread_name, MonitorChildProcessThreadFunction, info_ptr, NULL);
+      thread_name, MonitorChildProcessThreadFunction, info_ptr, nullptr);
 }
 
 #ifndef __linux__
@@ -219,7 +219,7 @@ static thread_result_t MonitorChildProcessThreadFunction(void *arg) {
       bool exited = false;
       int signal = 0;
       int exit_status = 0;
-      const char *status_cstr = NULL;
+      const char *status_cstr = nullptr;
       if (WIFSTOPPED(status)) {
         signal = WSTOPSIG(status);
         status_cstr = "STOPPED";
@@ -282,7 +282,7 @@ static thread_result_t MonitorChildProcessThreadFunction(void *arg) {
   if (log)
     log->Printf("%s (arg = %p) thread exiting...", __FUNCTION__, arg);
 
-  return NULL;
+  return nullptr;
 }
 
 #endif // #if !defined (__APPLE__) && !defined (_WIN32)
@@ -393,7 +393,7 @@ const char *Host::GetSignalAsCString(int signo) {
   default:
     break;
   }
-  return NULL;
+  return nullptr;
 }
 
 #endif
diff --git a/lldb/source/Host/common/HostNativeThreadBase.cpp b/lldb/source/Host/common/HostNativeThreadBase.cpp
index a5f876a7232..82f519e14f1 100644
--- a/lldb/source/Host/common/HostNativeThreadBase.cpp
+++ b/lldb/source/Host/common/HostNativeThreadBase.cpp
@@ -18,10 +18,10 @@ using namespace lldb;
 using namespace lldb_private;
 
 HostNativeThreadBase::HostNativeThreadBase()
-    : m_thread(LLDB_INVALID_HOST_THREAD), m_result(0) {}
+    : m_thread(LLDB_INVALID_HOST_THREAD), m_result(nullptr) {}
 
 HostNativeThreadBase::HostNativeThreadBase(thread_t thread)
-    : m_thread(thread), m_result(0) {}
+    : m_thread(thread), m_result(nullptr) {}
 
 lldb::thread_t HostNativeThreadBase::GetSystemHandle() const {
   return m_thread;
@@ -37,7 +37,7 @@ bool HostNativeThreadBase::IsJoinable() const {
 
 void HostNativeThreadBase::Reset() {
   m_thread = LLDB_INVALID_HOST_THREAD;
-  m_result = 0;
+  m_result = nullptr;
 }
 
 bool HostNativeThreadBase::EqualsThread(lldb::thread_t thread) const {
@@ -47,7 +47,7 @@ bool HostNativeThreadBase::EqualsThread(lldb::thread_t thread) const {
 lldb::thread_t HostNativeThreadBase::Release() {
   lldb::thread_t result = m_thread;
   m_thread = LLDB_INVALID_HOST_THREAD;
-  m_result = 0;
+  m_result = nullptr;
 
   return result;
 }
diff --git a/lldb/source/Host/common/OptionParser.cpp b/lldb/source/Host/common/OptionParser.cpp
index 97704988d36..92ff6f63d95 100644
--- a/lldb/source/Host/common/OptionParser.cpp
+++ b/lldb/source/Host/common/OptionParser.cpp
@@ -55,11 +55,11 @@ std::string OptionParser::GetShortOptionString(struct option *long_options) {
   int i = 0;
   bool done = false;
   while (!done) {
-    if (long_options[i].name == 0 && long_options[i].has_arg == 0 &&
-        long_options[i].flag == 0 && long_options[i].val == 0) {
+    if (long_options[i].name == nullptr && long_options[i].has_arg == 0 &&
+        long_options[i].flag == nullptr && long_options[i].val == 0) {
       done = true;
     } else {
-      if (long_options[i].flag == NULL && isalpha(long_options[i].val)) {
+      if (long_options[i].flag == nullptr && isalpha(long_options[i].val)) {
         s.append(1, (char)long_options[i].val);
         switch (long_options[i].has_arg) {
         default:
diff --git a/lldb/source/Host/common/ProcessRunLock.cpp b/lldb/source/Host/common/ProcessRunLock.cpp
index 65a5dcca31f..a931da71876 100644
--- a/lldb/source/Host/common/ProcessRunLock.cpp
+++ b/lldb/source/Host/common/ProcessRunLock.cpp
@@ -12,7 +12,7 @@
 namespace lldb_private {
 
 ProcessRunLock::ProcessRunLock() : m_running(false) {
-  int err = ::pthread_rwlock_init(&m_rwlock, NULL);
+  int err = ::pthread_rwlock_init(&m_rwlock, nullptr);
   (void)err;
 }
 
diff --git a/lldb/source/Host/common/SocketAddress.cpp b/lldb/source/Host/common/SocketAddress.cpp
index 06171d49bf6..882fd24558f 100644
--- a/lldb/source/Host/common/SocketAddress.cpp
+++ b/lldb/source/Host/common/SocketAddress.cpp
@@ -236,11 +236,11 @@ SocketAddress::GetAddressInfo(const char *hostname, const char *servname,
   hints.ai_protocol = ai_protocol;
   hints.ai_flags = ai_flags;
 
-  struct addrinfo *service_info_list = NULL;
+  struct addrinfo *service_info_list = nullptr;
   int err = ::getaddrinfo(hostname, servname, &hints, &service_info_list);
   if (err == 0 && service_info_list) {
-    for (struct addrinfo *service_ptr = service_info_list; service_ptr != NULL;
-         service_ptr = service_ptr->ai_next) {
+    for (struct addrinfo *service_ptr = service_info_list;
+         service_ptr != nullptr; service_ptr = service_ptr->ai_next) {
       addr_list.emplace_back(SocketAddress(service_ptr));
     }
   }
diff --git a/lldb/source/Host/common/TCPSocket.cpp b/lldb/source/Host/common/TCPSocket.cpp
index 3f11e4e3b49..f97ca9eb55b 100644
--- a/lldb/source/Host/common/TCPSocket.cpp
+++ b/lldb/source/Host/common/TCPSocket.cpp
@@ -143,7 +143,7 @@ Status TCPSocket::Connect(llvm::StringRef name) {
     return error;
 
   auto addresses = lldb_private::SocketAddress::GetAddressInfo(
-      host_str.c_str(), NULL, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
+      host_str.c_str(), nullptr, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
   for (auto address : addresses) {
     error = CreateSocket(address.GetFamily());
     if (error.Fail())
@@ -182,7 +182,7 @@ Status TCPSocket::Listen(llvm::StringRef name, int backlog) {
   if (host_str == "*")
     host_str = "0.0.0.0";
   auto addresses = lldb_private::SocketAddress::GetAddressInfo(
-      host_str.c_str(), NULL, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
+      host_str.c_str(), nullptr, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
   for (auto address : addresses) {
     int fd = Socket::CreateSocket(address.GetFamily(), kType, IPPROTO_TCP,
                                   m_child_processes_inherit, error);
diff --git a/lldb/source/Host/common/TaskPool.cpp b/lldb/source/Host/common/TaskPool.cpp
index 062fa4abd06..d63d9f35d1e 100644
--- a/lldb/source/Host/common/TaskPool.cpp
+++ b/lldb/source/Host/common/TaskPool.cpp
@@ -73,7 +73,7 @@ void TaskPoolImpl::AddTask(std::function<void()> &&task_fn) {
 
 lldb::thread_result_t TaskPoolImpl::WorkerPtr(void *pool) {
   Worker((TaskPoolImpl *)pool);
-  return 0;
+  return nullptr;
 }
 
 void TaskPoolImpl::Worker(TaskPoolImpl *pool) {
diff --git a/lldb/source/Host/common/Terminal.cpp b/lldb/source/Host/common/Terminal.cpp
index 9c60f0d1190..4b536b03d85 100644
--- a/lldb/source/Host/common/Terminal.cpp
+++ b/lldb/source/Host/common/Terminal.cpp
@@ -112,7 +112,7 @@ bool TerminalState::Save(int fd, bool save_process_group) {
     m_tflags = ::fcntl(fd, F_GETFL, 0);
 #endif
 #ifdef LLDB_CONFIG_TERMIOS_SUPPORTED
-    if (m_termios_up == NULL)
+    if (m_termios_up == nullptr)
       m_termios_up.reset(new struct termios);
     int err = ::tcgetattr(fd, m_termios_up.get());
     if (err != 0)
@@ -151,7 +151,7 @@ bool TerminalState::Restore() const {
 
     if (ProcessGroupIsValid()) {
       // Save the original signal handler.
-      void (*saved_sigttou_callback)(int) = NULL;
+      void (*saved_sigttou_callback)(int) = nullptr;
       saved_sigttou_callback = (void (*)(int))signal(SIGTTOU, SIG_IGN);
       // Set the process group
       tcsetpgrp(fd, m_process_group);
@@ -177,7 +177,7 @@ bool TerminalState::TFlagsIsValid() const { return m_tflags != -1; }
 // Returns true if m_ttystate is valid
 bool TerminalState::TTYStateIsValid() const {
 #ifdef LLDB_CONFIG_TERMIOS_SUPPORTED
-  return m_termios_up != 0;
+  return m_termios_up != nullptr;
 #else
   return false;
 #endif
diff --git a/lldb/source/Host/common/ThreadLauncher.cpp b/lldb/source/Host/common/ThreadLauncher.cpp
index ede864db108..2eff981bfa8 100644
--- a/lldb/source/Host/common/ThreadLauncher.cpp
+++ b/lldb/source/Host/common/ThreadLauncher.cpp
@@ -49,7 +49,7 @@ HostThread ThreadLauncher::LaunchThread(llvm::StringRef name,
   }
 #endif
 
-  pthread_attr_t *thread_attr_ptr = NULL;
+  pthread_attr_t *thread_attr_ptr = nullptr;
   pthread_attr_t thread_attr;
   bool destroy_attr = false;
   if (min_stack_byte_size > 0) {
diff --git a/lldb/source/Host/common/XML.cpp b/lldb/source/Host/common/XML.cpp
index 006b49f4e10..cb23ac17ef5 100644
--- a/lldb/source/Host/common/XML.cpp
+++ b/lldb/source/Host/common/XML.cpp
@@ -134,7 +134,7 @@ XMLNode XMLNode::GetChild() const {
 
 llvm::StringRef XMLNode::GetAttributeValue(const char *name,
                                            const char *fail_value) const {
-  const char *attr_value = NULL;
+  const char *attr_value = nullptr;
 #if defined(LIBXML2_DEFINED)
 
   if (IsValid())
diff --git a/lldb/source/Host/linux/Host.cpp b/lldb/source/Host/linux/Host.cpp
index 03fa798f0f5..f6a8766a71c 100644
--- a/lldb/source/Host/linux/Host.cpp
+++ b/lldb/source/Host/linux/Host.cpp
@@ -216,12 +216,12 @@ uint32_t Host::FindProcesses(const ProcessInstanceInfoMatch &match_info,
 
   DIR *dirproc = opendir(procdir);
   if (dirproc) {
-    struct dirent *direntry = NULL;
+    struct dirent *direntry = nullptr;
     const uid_t our_uid = getuid();
     const lldb::pid_t our_pid = getpid();
     bool all_users = match_info.GetMatchAllUsers();
 
-    while ((direntry = readdir(dirproc)) != NULL) {
+    while ((direntry = readdir(dirproc)) != nullptr) {
       if (direntry->d_type != DT_DIR || !IsDirNumeric(direntry->d_name))
         continue;
 
@@ -269,8 +269,8 @@ bool Host::FindProcessThreads(const lldb::pid_t pid, TidMap &tids_to_attach) {
   DIR *dirproc = opendir(process_task_dir.c_str());
 
   if (dirproc) {
-    struct dirent *direntry = NULL;
-    while ((direntry = readdir(dirproc)) != NULL) {
+    struct dirent *direntry = nullptr;
+    while ((direntry = readdir(dirproc)) != nullptr) {
       if (direntry->d_type != DT_DIR || !IsDirNumeric(direntry->d_name))
         continue;
 
diff --git a/lldb/source/Host/linux/HostInfoLinux.cpp b/lldb/source/Host/linux/HostInfoLinux.cpp
index 2b2207e7afa..78dd77b61fa 100644
--- a/lldb/source/Host/linux/HostInfoLinux.cpp
+++ b/lldb/source/Host/linux/HostInfoLinux.cpp
@@ -121,7 +121,8 @@ llvm::StringRef HostInfoLinux::GetDistributionId() {
 
       // retrieve the distribution id string.
       char distribution_id[256] = {'\0'};
-      if (fgets(distribution_id, sizeof(distribution_id) - 1, file) != NULL) {
+      if (fgets(distribution_id, sizeof(distribution_id) - 1, file) !=
+          nullptr) {
         if (log)
           log->Printf("distribution id command returned \"%s\"",
                       distribution_id);
diff --git a/lldb/source/Host/posix/ConnectionFileDescriptorPosix.cpp b/lldb/source/Host/posix/ConnectionFileDescriptorPosix.cpp
index 4bbebd627d4..167569dca69 100644
--- a/lldb/source/Host/posix/ConnectionFileDescriptorPosix.cpp
+++ b/lldb/source/Host/posix/ConnectionFileDescriptorPosix.cpp
@@ -111,7 +111,7 @@ ConnectionFileDescriptor::~ConnectionFileDescriptor() {
   if (log)
     log->Printf("%p ConnectionFileDescriptor::~ConnectionFileDescriptor ()",
                 static_cast<void *>(this));
-  Disconnect(NULL);
+  Disconnect(nullptr);
   CloseCommandPipe();
 }
 
diff --git a/lldb/source/Host/posix/HostThreadPosix.cpp b/lldb/source/Host/posix/HostThreadPosix.cpp
index caa137ae3d0..d78bba517f6 100644
--- a/lldb/source/Host/posix/HostThreadPosix.cpp
+++ b/lldb/source/Host/posix/HostThreadPosix.cpp
@@ -29,7 +29,7 @@ Status HostThreadPosix::Join(lldb::thread_result_t *result) {
     error.SetError(err, lldb::eErrorTypePOSIX);
   } else {
     if (result)
-      *result = NULL;
+      *result = nullptr;
     error.SetError(EINVAL, eErrorTypePOSIX);
   }