[compiler-rt] Apply modernize-use-nullptr fixes in sanitizers

- Trim spaces.
- Use nullptr in place of 0 for pointer variables.
- Use '!p' in place of 'p == 0' for null pointer checks.
- Add blank lines to separate function definitions.
- Add 'extern "C"' or 'namespace foo' comments after the appropriate
  closing brackets

This is a continuation of work from 409b7b82. The focus here is on the
various sanitizers (not sanitizer_common, as before).

Patch by Eugene Zelenko!

Differential Revision: http://reviews.llvm.org/D13225

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@248966 91177308-0d34-0410-b5e6-96231b3b80d8

24 files changed, 152 insertions, 138 deletions

diff --git a/lib/asan/asan_allocator.cc b/lib/asan/asan_allocator.cc
index 2df9a510b..56f184a36 100644
--- a/lib/asan/asan_allocator.cc
+++ b/lib/asan/asan_allocator.cc
@@ -14,8 +14,8 @@
 // with ThreadSanitizer and MemorySanitizer.
 //
 //===----------------------------------------------------------------------===//
-#include "asan_allocator.h"
 
+#include "asan_allocator.h"
 #include "asan_mapping.h"
 #include "asan_poisoning.h"
 #include "asan_report.h"
@@ -541,7 +541,7 @@ struct Allocator {
       u8 chunk_state = m->chunk_state;
       if (chunk_state != CHUNK_ALLOCATED)
         ReportInvalidFree(old_ptr, chunk_state, stack);
-      CHECK_NE(REAL(memcpy), (void*)0);
+      CHECK_NE(REAL(memcpy), nullptr);
       uptr memcpy_size = Min(new_size, m->UsedSize());
       // If realloc() races with free(), we may start copying freed memory.
       // However, we will report racy double-free later anyway.
@@ -579,7 +579,7 @@ struct Allocator {
 
   // Assumes alloc_beg == allocator.GetBlockBegin(alloc_beg).
   AsanChunk *GetAsanChunk(void *alloc_beg) {
-    if (!alloc_beg) return 0;
+    if (!alloc_beg) return nullptr;
     if (!allocator.FromPrimary(alloc_beg)) {
       uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(alloc_beg));
       AsanChunk *m = reinterpret_cast<AsanChunk *>(meta[1]);
@@ -619,7 +619,7 @@ struct Allocator {
       // The address is in the chunk's left redzone, so maybe it is actually
       // a right buffer overflow from the other chunk to the left.
       // Search a bit to the left to see if there is another chunk.
-      AsanChunk *m2 = 0;
+      AsanChunk *m2 = nullptr;
       for (uptr l = 1; l < GetPageSizeCached(); l++) {
         m2 = GetAsanChunkByAddr(addr - l);
         if (m2 == m1) continue;  // Still the same chunk.
@@ -653,7 +653,7 @@ static AsanAllocator &get_allocator() {
 }
 
 bool AsanChunkView::IsValid() {
-  return chunk_ != 0 && chunk_->chunk_state != CHUNK_AVAILABLE;
+  return chunk_ && chunk_->chunk_state != CHUNK_AVAILABLE;
 }
 uptr AsanChunkView::Beg() { return chunk_->Beg(); }
 uptr AsanChunkView::End() { return Beg() + UsedSize(); }
@@ -723,11 +723,11 @@ void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
 }
 
 void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
-  if (p == 0)
+  if (!p)
     return instance.Allocate(size, 8, stack, FROM_MALLOC, true);
   if (size == 0) {
     instance.Deallocate(p, 0, stack, FROM_MALLOC);
-    return 0;
+    return nullptr;
   }
   return instance.Reallocate(p, size, stack);
 }
@@ -755,7 +755,7 @@ int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
 }
 
 uptr asan_malloc_usable_size(void *ptr, uptr pc, uptr bp) {
-  if (ptr == 0) return 0;
+  if (!ptr) return 0;
   uptr usable_size = instance.AllocationSize(reinterpret_cast<uptr>(ptr));
   if (flags()->check_malloc_usable_size && (usable_size == 0)) {
     GET_STACK_TRACE_FATAL(pc, bp);
@@ -780,7 +780,7 @@ void AsanSoftRssLimitExceededCallback(bool exceeded) {
   instance.allocator.SetRssLimitIsExceeded(exceeded);
 }
 
-}  // namespace __asan
+} // namespace __asan
 
 // --- Implementation of LSan-specific functions --- {{{1
 namespace __lsan {
@@ -881,7 +881,7 @@ int __sanitizer_get_ownership(const void *p) {
 }
 
 uptr __sanitizer_get_allocated_size(const void *p) {
-  if (p == 0) return 0;
+  if (!p) return 0;
   uptr ptr = reinterpret_cast<uptr>(p);
   uptr allocated_size = instance.AllocationSize(ptr);
   // Die if p is not malloced or if it is already freed.
@@ -904,5 +904,5 @@ SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 void __sanitizer_free_hook(void *ptr) {
   (void)ptr;
 }
-}  // extern "C"
+} // extern "C"
 #endif
diff --git a/lib/asan/asan_debugging.cc b/lib/asan/asan_debugging.cc
index 6fc5b690d..7c3a8a73b 100644
--- a/lib/asan/asan_debugging.cc
+++ b/lib/asan/asan_debugging.cc
@@ -108,14 +108,14 @@ static uptr AsanGetStack(uptr addr, uptr *trace, u32 size, u32 *thread_id,
   return 0;
 }
 
-}  // namespace __asan
+} // namespace __asan
 
 using namespace __asan;
 
 SANITIZER_INTERFACE_ATTRIBUTE
 const char *__asan_locate_address(uptr addr, char *name, uptr name_size,
                                   uptr *region_address, uptr *region_size) {
-  AddressDescription descr = { name, name_size, 0, 0, 0 };
+  AddressDescription descr = { name, name_size, 0, 0, nullptr };
   AsanLocateAddress(addr, &descr);
   if (region_address) *region_address = descr.region_address;
   if (region_size) *region_size = descr.region_size;
diff --git a/lib/asan/asan_fake_stack.cc b/lib/asan/asan_fake_stack.cc
index cd8379b56..463b7caf0 100644
--- a/lib/asan/asan_fake_stack.cc
+++ b/lib/asan/asan_fake_stack.cc
@@ -11,6 +11,7 @@
 //
 // FakeStack is used to detect use-after-return bugs.
 //===----------------------------------------------------------------------===//
+
 #include "asan_allocator.h"
 #include "asan_poisoning.h"
 #include "asan_thread.h"
@@ -32,7 +33,7 @@ ALWAYS_INLINE void SetShadow(uptr ptr, uptr size, uptr class_id, u64 magic) {
   if (class_id <= 6) {
     for (uptr i = 0; i < (1U << class_id); i++) {
       shadow[i] = magic;
-      SanitizerBreakOptimization(0);  // Make sure this does not become memset.
+      SanitizerBreakOptimization(nullptr);  // Make sure this does not become memset.
     }
   } else {
     // The size class is too big, it's cheaper to poison only size bytes.
@@ -108,7 +109,7 @@ FakeFrame *FakeStack::Allocate(uptr stack_size_log, uptr class_id,
     *SavedFlagPtr(reinterpret_cast<uptr>(res), class_id) = &flags[pos];
     return res;
   }
-  return 0; // We are out of fake stack.
+  return nullptr; // We are out of fake stack.
 }
 
 uptr FakeStack::AddrIsInFakeStack(uptr ptr, uptr *frame_beg, uptr *frame_end) {
@@ -185,7 +186,7 @@ void SetTLSFakeStack(FakeStack *fs) { }
 
 static FakeStack *GetFakeStack() {
   AsanThread *t = GetCurrentThread();
-  if (!t) return 0;
+  if (!t) return nullptr;
   return t->fake_stack();
 }
 
@@ -193,7 +194,7 @@ static FakeStack *GetFakeStackFast() {
   if (FakeStack *fs = GetTLSFakeStack())
     return fs;
   if (!__asan_option_detect_stack_use_after_return)
-    return 0;
+    return nullptr;
   return GetFakeStack();
 }
 
@@ -214,7 +215,7 @@ ALWAYS_INLINE void OnFree(uptr ptr, uptr class_id, uptr size) {
   SetShadow(ptr, size, class_id, kMagic8);
 }
 
-}  // namespace __asan
+} // namespace __asan
 
 // ---------------------- Interface ---------------- {{{1
 using namespace __asan;
@@ -247,13 +248,13 @@ SANITIZER_INTERFACE_ATTRIBUTE
 void *__asan_addr_is_in_fake_stack(void *fake_stack, void *addr, void **beg,
                                    void **end) {
   FakeStack *fs = reinterpret_cast<FakeStack*>(fake_stack);
-  if (!fs) return 0;
+  if (!fs) return nullptr;
   uptr frame_beg, frame_end;
   FakeFrame *frame = reinterpret_cast<FakeFrame *>(fs->AddrIsInFakeStack(
       reinterpret_cast<uptr>(addr), &frame_beg, &frame_end));
-  if (!frame) return 0;
+  if (!frame) return nullptr;
   if (frame->magic != kCurrentStackFrameMagic)
-    return 0;
+    return nullptr;
   if (beg) *beg = reinterpret_cast<void*>(frame_beg);
   if (end) *end = reinterpret_cast<void*>(frame_end);
   return reinterpret_cast<void*>(frame->real_stack);
@@ -278,4 +279,4 @@ void __asan_allocas_unpoison(uptr top, uptr bottom) {
   REAL(memset)(reinterpret_cast<void*>(MemToShadow(top)), 0,
                (bottom - top) / SHADOW_GRANULARITY);
 }
-}  // extern "C"
+} // extern "C"
diff --git a/lib/asan/asan_globals.cc b/lib/asan/asan_globals.cc
index c34b1d3ce..eb9f1bfef 100644
--- a/lib/asan/asan_globals.cc
+++ b/lib/asan/asan_globals.cc
@@ -11,6 +11,7 @@
 //
 // Handle globals.
 //===----------------------------------------------------------------------===//
+
 #include "asan_interceptors.h"
 #include "asan_internal.h"
 #include "asan_mapping.h"
@@ -167,7 +168,7 @@ static void RegisterGlobal(const Global *g) {
   l->next = list_of_all_globals;
   list_of_all_globals = l;
   if (g->has_dynamic_init) {
-    if (dynamic_init_globals == 0) {
+    if (!dynamic_init_globals) {
       dynamic_init_globals = new(allocator_for_globals)
           VectorOfGlobals(kDynamicInitGlobalsInitialCapacity);
     }
@@ -206,7 +207,7 @@ void StopInitOrderChecking() {
   }
 }
 
-}  // namespace __asan
+} // namespace __asan
 
 // ---------------------- Interface ---------------- {{{1
 using namespace __asan;  // NOLINT
diff --git a/lib/asan/asan_interceptors.cc b/lib/asan/asan_interceptors.cc
index 8307408b1..5a7a91b8f 100644
--- a/lib/asan/asan_interceptors.cc
+++ b/lib/asan/asan_interceptors.cc
@@ -11,8 +11,8 @@
 //
 // Intercept various libc functions.
 //===----------------------------------------------------------------------===//
-#include "asan_interceptors.h"
 
+#include "asan_interceptors.h"
 #include "asan_allocator.h"
 #include "asan_internal.h"
 #include "asan_mapping.h"
@@ -109,7 +109,7 @@ static inline bool RangesOverlap(const char *offset1, uptr length1,
 
 static inline uptr MaybeRealStrnlen(const char *s, uptr maxlen) {
 #if ASAN_INTERCEPT_STRNLEN
-  if (REAL(strnlen) != 0) {
+  if (REAL(strnlen)) {
     return REAL(strnlen)(s, maxlen);
   }
 #endif
@@ -127,7 +127,7 @@ int OnExit() {
   return 0;
 }
 
-}  // namespace __asan
+} // namespace __asan
 
 // ---------------------- Wrappers ---------------- {{{1
 using namespace __asan;  // NOLINT
@@ -220,7 +220,7 @@ static thread_return_t THREAD_CALLING_CONV asan_thread_start(void *arg) {
   ThreadStartParam *param = reinterpret_cast<ThreadStartParam *>(arg);
   AsanThread *t = nullptr;
   while ((t = reinterpret_cast<AsanThread *>(
-              atomic_load(&param->t, memory_order_acquire))) == 0)
+              atomic_load(&param->t, memory_order_acquire))) == nullptr)
     internal_sched_yield();
   SetCurrentThread(t);
   return t->ThreadStart(GetTid(), &param->is_registered);
@@ -235,7 +235,7 @@ INTERCEPTOR(int, pthread_create, void *thread,
     StopInitOrderChecking();
   GET_STACK_TRACE_THREAD;
   int detached = 0;
-  if (attr != 0)
+  if (attr)
     REAL(pthread_attr_getdetachstate)(attr, &detached);
   ThreadStartParam param;
   atomic_store(&param.t, 0, memory_order_relaxed);
@@ -280,7 +280,7 @@ INTERCEPTOR(void*, signal, int signum, void *handler) {
   if (!IsDeadlySignal(signum) || common_flags()->allow_user_segv_handler) {
     return REAL(signal)(signum, handler);
   }
-  return 0;
+  return nullptr;
 }
 
 INTERCEPTOR(int, sigaction, int signum, const struct sigaction *act,
@@ -296,7 +296,7 @@ int real_sigaction(int signum, const void *act, void *oldact) {
   return REAL(sigaction)(signum, (const struct sigaction *)act,
                          (struct sigaction *)oldact);
 }
-}  // namespace __sanitizer
+} // namespace __sanitizer
 
 #elif SANITIZER_POSIX
 // We need to have defined REAL(sigaction) on posix systems.
@@ -713,7 +713,7 @@ INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
 #endif
   ENSURE_ASAN_INITED();
   int res = REAL(__cxa_atexit)(func, arg, dso_handle);
-  REAL(__cxa_atexit)(AtCxaAtexit, 0, 0);
+  REAL(__cxa_atexit)(AtCxaAtexit, nullptr, nullptr);
   return res;
 }
 #endif  // ASAN_INTERCEPT___CXA_ATEXIT
@@ -817,4 +817,4 @@ void InitializeAsanInterceptors() {
   VReport(1, "AddressSanitizer: libc interceptors initialized\n");
 }
 
-}  // namespace __asan
+} // namespace __asan
diff --git a/lib/asan/asan_linux.cc b/lib/asan/asan_linux.cc
index 70f5d1708..804aef737 100644
--- a/lib/asan/asan_linux.cc
+++ b/lib/asan/asan_linux.cc
@@ -117,7 +117,7 @@ void AsanCheckDynamicRTPrereqs() {
     return;
 
   // Ensure that dynamic RT is the first DSO in the list
-  const char *first_dso_name = 0;
+  const char *first_dso_name = nullptr;
   dl_iterate_phdr(FindFirstDSOCallback, &first_dso_name);
   if (first_dso_name && !IsDynamicRTName(first_dso_name)) {
     Report("ASan runtime does not come first in initial library list; "
@@ -142,7 +142,8 @@ void AsanCheckIncompatibleRT() {
       // system libraries, causing crashes later in ASan initialization.
       MemoryMappingLayout proc_maps(/*cache_enabled*/true);
       char filename[128];
-      while (proc_maps.Next(0, 0, 0, filename, sizeof(filename), 0)) {
+      while (proc_maps.Next(nullptr, nullptr, nullptr, filename,
+                            sizeof(filename), nullptr)) {
         if (IsDynamicRTName(filename)) {
           Report("Your application is linked against "
                  "incompatible ASan runtimes.\n");
@@ -155,7 +156,7 @@ void AsanCheckIncompatibleRT() {
     }
   }
 }
-#endif  // SANITIZER_ANDROID
+#endif // SANITIZER_ANDROID
 
 #if !SANITIZER_ANDROID
 void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
@@ -173,6 +174,6 @@ void *AsanDlSymNext(const char *sym) {
   return dlsym(RTLD_NEXT, sym);
 }
 
-}  // namespace __asan
+} // namespace __asan
 
-#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX
+#endif // SANITIZER_FREEBSD || SANITIZER_LINUX
diff --git a/lib/asan/asan_report.cc b/lib/asan/asan_report.cc
index 1cc45ddee..957ac14ea 100644
--- a/lib/asan/asan_report.cc
+++ b/lib/asan/asan_report.cc
@@ -11,6 +11,7 @@
 //
 // This file contains error reporting code.
 //===----------------------------------------------------------------------===//
+
 #include "asan_flags.h"
 #include "asan_internal.h"
 #include "asan_mapping.h"
@@ -27,7 +28,7 @@ namespace __asan {
 
 // -------------------- User-specified callbacks ----------------- {{{1
 static void (*error_report_callback)(const char*);
-static char *error_message_buffer = 0;
+static char *error_message_buffer = nullptr;
 static uptr error_message_buffer_pos = 0;
 static uptr error_message_buffer_size = 0;
 
@@ -373,7 +374,7 @@ static void PrintAccessAndVarIntersection(const StackVarDescr &var, uptr addr,
                                           uptr next_var_beg) {
   uptr var_end = var.beg + var.size;
   uptr addr_end = addr + access_size;
-  const char *pos_descr = 0;
+  const char *pos_descr = nullptr;
   // If the variable [var.beg, var_end) is the nearest variable to the
   // current memory access, indicate it in the log.
   if (addr >= var.beg) {
@@ -544,7 +545,7 @@ void DescribeHeapAddress(uptr addr, uptr access_size) {
   StackTrace alloc_stack = chunk.GetAllocStack();
   char tname[128];
   Decorator d;
-  AsanThreadContext *free_thread = 0;
+  AsanThreadContext *free_thread = nullptr;
   if (chunk.FreeTid() != kInvalidTid) {
     free_thread = GetThreadContextByTidLocked(chunk.FreeTid());
     Printf("%sfreed by thread T%d%s here:%s\n", d.Allocation(),
@@ -958,7 +959,7 @@ void ReportMacCfReallocUnknown(uptr addr, uptr zone_ptr, const char *zone_name,
   DescribeHeapAddress(addr, 1);
 }
 
-}  // namespace __asan
+} // namespace __asan
 
 // --------------------------- Interface --------------------- {{{1
 using namespace __asan;  // NOLINT
@@ -1117,7 +1118,7 @@ SANITIZER_INTERFACE_ATTRIBUTE
 void __sanitizer_ptr_cmp(void *a, void *b) {
   CheckForInvalidPointerPair(a, b);
 }
-}  // extern "C"
+} // extern "C"
 
 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
 // Provide default implementation of __asan_on_error that does nothing
diff --git a/lib/asan/asan_rtl.cc b/lib/asan/asan_rtl.cc
index effb68020..c744ac251 100644
--- a/lib/asan/asan_rtl.cc
+++ b/lib/asan/asan_rtl.cc
@@ -11,6 +11,7 @@
 //
 // Main file of the ASan run-time library.
 //===----------------------------------------------------------------------===//
+
 #include "asan_activation.h"
 #include "asan_allocator.h"
 #include "asan_interceptors.h"
@@ -254,15 +255,15 @@ static NOINLINE void force_interface_symbols() {
     case 22: __asan_report_exp_store8(0, 0); break;
     case 23: __asan_report_exp_store16(0, 0); break;
     case 24: __asan_report_exp_store_n(0, 0, 0); break;
-    case 25: __asan_register_globals(0, 0); break;
-    case 26: __asan_unregister_globals(0, 0); break;
-    case 27: __asan_set_death_callback(0); break;
-    case 28: __asan_set_error_report_callback(0); break;
+    case 25: __asan_register_globals(nullptr, 0); break;
+    case 26: __asan_unregister_globals(nullptr, 0); break;
+    case 27: __asan_set_death_callback(nullptr); break;
+    case 28: __asan_set_error_report_callback(nullptr); break;
     case 29: __asan_handle_no_return(); break;
-    case 30: __asan_address_is_poisoned(0); break;
-    case 31: __asan_poison_memory_region(0, 0); break;
-    case 32: __asan_unpoison_memory_region(0, 0); break;
-    case 34: __asan_before_dynamic_init(0); break;
+    case 30: __asan_address_is_poisoned(nullptr); break;
+    case 31: __asan_poison_memory_region(nullptr, 0); break;
+    case 32: __asan_unpoison_memory_region(nullptr, 0); break;
+    case 34: __asan_before_dynamic_init(nullptr); break;
     case 35: __asan_after_dynamic_init(); break;
     case 36: __asan_poison_stack_memory(0, 0); break;
     case 37: __asan_unpoison_stack_memory(0, 0); break;
@@ -541,7 +542,7 @@ public:  // NOLINT
 static AsanInitializer asan_initializer;
 #endif  // ASAN_DYNAMIC
 
-}  // namespace __asan
+} // namespace __asan
 
 // ---------------------- Interface ---------------- {{{1
 using namespace __asan;  // NOLINT
diff --git a/lib/asan/asan_stack.h b/lib/asan/asan_stack.h
index 122967a15..5c5181509 100644
--- a/lib/asan/asan_stack.h
+++ b/lib/asan/asan_stack.h
@@ -11,6 +11,7 @@
 //
 // ASan-private header for asan_stack.cc.
 //===----------------------------------------------------------------------===//
+
 #ifndef ASAN_STACK_H
 #define ASAN_STACK_H
 
@@ -48,15 +49,15 @@ void GetStackTraceWithPcBpAndContext(BufferedStackTrace *stack, uptr max_depth,
       uptr stack_bottom = t->stack_bottom();
       ScopedUnwinding unwind_scope(t);
       stack->Unwind(max_depth, pc, bp, context, stack_top, stack_bottom, fast);
-    } else if (t == 0 && !fast) {
+    } else if (!t && !fast) {
       /* If GetCurrentThread() has failed, try to do slow unwind anyways. */
       stack->Unwind(max_depth, pc, bp, context, 0, 0, false);
     }
   }
-#endif  // SANITIZER_WINDOWS
+#endif // SANITIZER_WINDOWS
 }
 
-}  // namespace __asan
+} // namespace __asan
 
 // NOTE: A Rule of thumb is to retrieve stack trace in the interceptors
 // as early as possible (in functions exposed to the user), as we generally
@@ -115,4 +116,4 @@ void GetStackTraceWithPcBpAndContext(BufferedStackTrace *stack, uptr max_depth,
     stack.Print();                  \
   }
 
-#endif  // ASAN_STACK_H
+#endif // ASAN_STACK_H
diff --git a/lib/asan/asan_thread.cc b/lib/asan/asan_thread.cc
index d135b7b9d..69813546f 100644
--- a/lib/asan/asan_thread.cc
+++ b/lib/asan/asan_thread.cc
@@ -42,7 +42,7 @@ void AsanThreadContext::OnCreated(void *arg) {
 
 void AsanThreadContext::OnFinished() {
   // Drop the link to the AsanThread object.
-  thread = 0;
+  thread = nullptr;
 }
 
 // MIPS requires aligned address
@@ -125,7 +125,7 @@ void AsanThread::Destroy() {
 FakeStack *AsanThread::AsyncSignalSafeLazyInitFakeStack() {
   uptr stack_size = this->stack_size();
   if (stack_size == 0)  // stack_size is not yet available, don't use FakeStack.
-    return 0;
+    return nullptr;
   uptr old_val = 0;
   // fake_stack_ has 3 states:
   // 0   -- not initialized
@@ -146,11 +146,11 @@ FakeStack *AsanThread::AsyncSignalSafeLazyInitFakeStack() {
     SetTLSFakeStack(fake_stack_);
     return fake_stack_;
   }
-  return 0;
+  return nullptr;
 }
 
 void AsanThread::Init() {
-  fake_stack_ = 0;  // Will be initialized lazily if needed.
+  fake_stack_ = nullptr;  // Will be initialized lazily if needed.
   CHECK_EQ(this->stack_size(), 0U);
   SetThreadStackAndTls();
   CHECK_GT(this->stack_size(), 0U);
@@ -166,7 +166,7 @@ void AsanThread::Init() {
 thread_return_t AsanThread::ThreadStart(
     uptr os_id, atomic_uintptr_t *signal_thread_is_registered) {
   Init();
-  asanThreadRegistry().StartThread(tid(), os_id, 0);
+  asanThreadRegistry().StartThread(tid(), os_id, nullptr);
   if (signal_thread_is_registered)
     atomic_store(signal_thread_is_registered, 1, memory_order_release);
 
@@ -276,7 +276,7 @@ AsanThread *GetCurrentThread() {
         return tctx->thread;
       }
     }
-    return 0;
+    return nullptr;
   }
   return context->thread;
 }
@@ -301,7 +301,7 @@ AsanThread *FindThreadByStackAddress(uptr addr) {
   AsanThreadContext *tctx = static_cast<AsanThreadContext *>(
       asanThreadRegistry().FindThreadContextLocked(ThreadStackContainsAddress,
                                                    (void *)addr));
-  return tctx ? tctx->thread : 0;
+  return tctx ? tctx->thread : nullptr;
 }
 
 void EnsureMainThreadIDIsCorrect() {
@@ -314,10 +314,10 @@ void EnsureMainThreadIDIsCorrect() {
 __asan::AsanThread *GetAsanThreadByOsIDLocked(uptr os_id) {
   __asan::AsanThreadContext *context = static_cast<__asan::AsanThreadContext *>(
       __asan::asanThreadRegistry().FindThreadContextByOsIDLocked(os_id));
-  if (!context) return 0;
+  if (!context) return nullptr;
   return context->thread;
 }
-}  // namespace __asan
+} // namespace __asan
 
 // --- Implementation of LSan-specific functions --- {{{1
 namespace __lsan {
@@ -354,4 +354,4 @@ void UnlockThreadRegistry() {
 void EnsureMainThreadIDIsCorrect() {
   __asan::EnsureMainThreadIDIsCorrect();
 }
-}  // namespace __lsan
+} // namespace __lsan
diff --git a/lib/asan/asan_thread.h b/lib/asan/asan_thread.h
index 50acfc42d..ac35711f5 100644
--- a/lib/asan/asan_thread.h
+++ b/lib/asan/asan_thread.h
@@ -11,6 +11,7 @@
 //
 // ASan-private header for asan_thread.cc.
 //===----------------------------------------------------------------------===//
+
 #ifndef ASAN_THREAD_H
 #define ASAN_THREAD_H
 
@@ -36,7 +37,7 @@ class AsanThreadContext : public ThreadContextBase {
   explicit AsanThreadContext(int tid)
       : ThreadContextBase(tid), announced(false),
         destructor_iterations(GetPthreadDestructorIterations()), stack_id(0),
-        thread(0) {}
+        thread(nullptr) {}
   bool announced;
   u8 destructor_iterations;
   u32 stack_id;
@@ -84,8 +85,8 @@ class AsanThread {
   void DeleteFakeStack(int tid) {
     if (!fake_stack_) return;
     FakeStack *t = fake_stack_;
-    fake_stack_ = 0;
-    SetTLSFakeStack(0);
+    fake_stack_ = nullptr;
+    SetTLSFakeStack(nullptr);
     t->Destroy(tid);
   }
 
@@ -95,7 +96,7 @@ class AsanThread {
 
   FakeStack *fake_stack() {
     if (!__asan_option_detect_stack_use_after_return)
-      return 0;
+      return nullptr;
     if (!has_fake_stack())
       return AsyncSignalSafeLazyInitFakeStack();
     return fake_stack_;
@@ -179,6 +180,6 @@ AsanThread *FindThreadByStackAddress(uptr addr);
 
 // Used to handle fork().
 void EnsureMainThreadIDIsCorrect();
-}  // namespace __asan
+} // namespace __asan
 
-#endif  // ASAN_THREAD_H
+#endif // ASAN_THREAD_H
diff --git a/lib/dfsan/dfsan_custom.cc b/lib/dfsan/dfsan_custom.cc
index 815896da6..e0cd16ab6 100644
--- a/lib/dfsan/dfsan_custom.cc
+++ b/lib/dfsan/dfsan_custom.cc
@@ -85,7 +85,7 @@ SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c,
         *ret_label = dfsan_union(dfsan_read_label(s, i + 1),
                                  dfsan_union(s_label, c_label));
       }
-      return s[i] == 0 ? 0 : const_cast<char *>(s+i);
+      return s[i] == 0 ? nullptr : const_cast<char *>(s+i);
     }
   }
 }
@@ -848,8 +848,8 @@ typedef void (*write_trampoline_t)(
 // Calls to dfsan_set_write_callback() set the values in this struct.
 // Calls to the custom version of write() read (and invoke) them.
 static struct {
-  write_trampoline_t write_callback_trampoline = NULL;
-  void *write_callback = NULL;
+  write_trampoline_t write_callback_trampoline = nullptr;
+  void *write_callback = nullptr;
 } write_callback_info;
 
 SANITIZER_INTERFACE_ATTRIBUTE void
@@ -866,7 +866,7 @@ SANITIZER_INTERFACE_ATTRIBUTE int
 __dfsw_write(int fd, const void *buf, size_t count,
              dfsan_label fd_label, dfsan_label buf_label,
              dfsan_label count_label, dfsan_label *ret_label) {
-  if (write_callback_info.write_callback != NULL) {
+  if (write_callback_info.write_callback) {
     write_callback_info.write_callback_trampoline(
         write_callback_info.write_callback,
         fd, buf, count,
@@ -876,7 +876,7 @@ __dfsw_write(int fd, const void *buf, size_t count,
   *ret_label = 0;
   return write(fd, buf, count);
 }
-}
+} // namespace __dfsan
 
 // Type used to extract a dfsan_label with va_arg()
 typedef int dfsan_label_va;
@@ -1132,4 +1132,4 @@ int __dfsw_snprintf(char *str, size_t size, const char *format,
   va_end(ap);
   return ret;
 }
-}
+} // extern "C"
diff --git a/lib/lsan/lsan_allocator.cc b/lib/lsan/lsan_allocator.cc
index 5611a3bcb..9daabf33b 100644
--- a/lib/lsan/lsan_allocator.cc
+++ b/lib/lsan/lsan_allocator.cc
@@ -91,7 +91,7 @@ void *Allocate(const StackTrace &stack, uptr size, uptr alignment,
     size = 1;
   if (size > kMaxAllowedMallocSize) {
     Report("WARNING: LeakSanitizer failed to allocate %zu bytes\n", size);
-    return 0;
+    return nullptr;
   }
   void *p = allocator.Allocate(&cache, size, alignment, false);
   // Do not rely on the allocator to clear the memory (it's slow).
@@ -114,7 +114,7 @@ void *Reallocate(const StackTrace &stack, void *p, uptr new_size,
   if (new_size > kMaxAllowedMallocSize) {
     Report("WARNING: LeakSanitizer failed to allocate %zu bytes\n", new_size);
     allocator.Deallocate(&cache, p);
-    return 0;
+    return nullptr;
   }
   p = allocator.Reallocate(&cache, p, new_size, alignment);
   RegisterAllocation(stack, p, new_size);
@@ -212,7 +212,7 @@ IgnoreObjectResult IgnoreObjectLocked(const void *p) {
     return kIgnoreObjectInvalid;
   }
 }
-}  // namespace __lsan
+} // namespace __lsan
 
 using namespace __lsan;
 
@@ -241,10 +241,10 @@ SANITIZER_INTERFACE_ATTRIBUTE
 uptr __sanitizer_get_estimated_allocated_size(uptr size) { return size; }
 
 SANITIZER_INTERFACE_ATTRIBUTE
-int __sanitizer_get_ownership(const void *p) { return Metadata(p) != 0; }
+int __sanitizer_get_ownership(const void *p) { return Metadata(p) != nullptr; }
 
 SANITIZER_INTERFACE_ATTRIBUTE
 uptr __sanitizer_get_allocated_size(const void *p) {
   return GetMallocUsableSize(p);
 }
-}  // extern "C"
+} // extern "C"
diff --git a/lib/lsan/lsan_common.cc b/lib/lsan/lsan_common.cc
index 14dddedd5..18467f14e 100644
--- a/lib/lsan/lsan_common.cc
+++ b/lib/lsan/lsan_common.cc
@@ -243,8 +243,8 @@ static void ProcessRootRegion(Frontier *frontier, uptr root_begin,
   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
   uptr begin, end, prot;
   while (proc_maps.Next(&begin, &end,
-                        /*offset*/ 0, /*filename*/ 0, /*filename_size*/ 0,
-                        &prot)) {
+                        /*offset*/ nullptr, /*filename*/ nullptr,
+                        /*filename_size*/ 0, &prot)) {
     uptr intersection_begin = Max(root_begin, begin);
     uptr intersection_end = Min(end, root_end);
     if (intersection_begin >= intersection_end) continue;
@@ -484,7 +484,7 @@ static Suppression *GetSuppressionForStack(u32 stack_trace_id) {
         StackTrace::GetPreviousInstructionPc(stack.trace[i]));
     if (s) return s;
   }
-  return 0;
+  return nullptr;
 }
 
 ///// LeakReport implementation. /////
@@ -612,8 +612,8 @@ uptr LeakReport::UnsuppressedLeakCount() {
   return result;
 }
 
-}  // namespace __lsan
-#endif  // CAN_SANITIZE_LEAKS
+} // namespace __lsan
+#endif // CAN_SANITIZE_LEAKS
 
 using namespace __lsan;  // NOLINT
 
@@ -634,7 +634,7 @@ void __lsan_ignore_object(const void *p) {
            "heap object at %p is already being ignored\n", p);
   if (res == kIgnoreObjectSuccess)
     VReport(1, "__lsan_ignore_object(): ignoring heap object at %p\n", p);
-#endif  // CAN_SANITIZE_LEAKS
+#endif // CAN_SANITIZE_LEAKS
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
@@ -645,7 +645,7 @@ void __lsan_register_root_region(const void *begin, uptr size) {
   RootRegion region = {begin, size};
   root_regions->push_back(region);
   VReport(1, "Registered root region at %p of size %llu\n", begin, size);
-#endif  // CAN_SANITIZE_LEAKS
+#endif // CAN_SANITIZE_LEAKS
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
@@ -672,7 +672,7 @@ void __lsan_unregister_root_region(const void *begin, uptr size) {
         begin, size);
     Die();
   }
-#endif  // CAN_SANITIZE_LEAKS
+#endif // CAN_SANITIZE_LEAKS
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
@@ -698,7 +698,7 @@ void __lsan_do_leak_check() {
 #if CAN_SANITIZE_LEAKS
   if (common_flags()->detect_leaks)
     __lsan::DoLeakCheck();
-#endif  // CAN_SANITIZE_LEAKS
+#endif // CAN_SANITIZE_LEAKS
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
@@ -706,7 +706,7 @@ int __lsan_do_recoverable_leak_check() {
 #if CAN_SANITIZE_LEAKS
   if (common_flags()->detect_leaks)
     return __lsan::DoRecoverableLeakCheck();
-#endif  // CAN_SANITIZE_LEAKS
+#endif // CAN_SANITIZE_LEAKS
   return 0;
 }
 
@@ -716,4 +716,4 @@ int __lsan_is_turned_off() {
   return 0;
 }
 #endif
-}  // extern "C"
+} // extern "C"
diff --git a/lib/lsan/lsan_common_linux.cc b/lib/lsan/lsan_common_linux.cc
index 2955343e1..1dc0561da 100644
--- a/lib/lsan/lsan_common_linux.cc
+++ b/lib/lsan/lsan_common_linux.cc
@@ -29,7 +29,7 @@ static const char kLinkerName[] = "ld";
 // We request 2 modules matching "ld", so we can print a warning if there's more
 // than one match. But only the first one is actually used.
 static char linker_placeholder[2 * sizeof(LoadedModule)] ALIGNED(64);
-static LoadedModule *linker = 0;
+static LoadedModule *linker = nullptr;
 
 static bool IsLinker(const char* full_name) {
   return LibraryNameIs(full_name, kLinkerName);
@@ -49,7 +49,7 @@ void InitializePlatformSpecificModules() {
   else if (num_matches > 1)
     VReport(1, "LeakSanitizer: Multiple modules match \"%s\". "
             "TLS will not be handled correctly.\n", kLinkerName);
-  linker = 0;
+  linker = nullptr;
 }
 
 static int ProcessGlobalRegionsCallback(struct dl_phdr_info *info, size_t size,
@@ -174,5 +174,6 @@ void DoStopTheWorld(StopTheWorldCallback callback, void *argument) {
   dl_iterate_phdr(DoStopTheWorldCallback, &param);
 }
 
-}  // namespace __lsan
-#endif  // CAN_SANITIZE_LEAKS && SANITIZER_LINUX
+} // namespace __lsan
+
+#endif // CAN_SANITIZE_LEAKS && SANITIZER_LINUX
diff --git a/lib/lsan/lsan_interceptors.cc b/lib/lsan/lsan_interceptors.cc
index 84679e431..be0d0ddc2 100644
--- a/lib/lsan/lsan_interceptors.cc
+++ b/lib/lsan/lsan_interceptors.cc
@@ -71,7 +71,7 @@ INTERCEPTOR(void*, calloc, uptr nmemb, uptr size) {
     CHECK(allocated < kCallocPoolSize);
     return mem;
   }
-  if (CallocShouldReturnNullDueToOverflow(size, nmemb)) return 0;
+  if (CallocShouldReturnNullDueToOverflow(size, nmemb)) return nullptr;
   ENSURE_LSAN_INITED;
   GET_STACK_TRACE_MALLOC;
   size *= nmemb;
@@ -226,7 +226,7 @@ INTERCEPTOR(int, pthread_create, void *th, void *attr,
   ENSURE_LSAN_INITED;
   EnsureMainThreadIDIsCorrect();
   __sanitizer_pthread_attr_t myattr;
-  if (attr == 0) {
+  if (!attr) {
     pthread_attr_init(&myattr);
     attr = &myattr;
   }
@@ -284,4 +284,4 @@ void InitializeInterceptors() {
   }
 }
 
-}  // namespace __lsan
+} // namespace __lsan
diff --git a/lib/lsan/lsan_thread.cc b/lib/lsan/lsan_thread.cc
index 0f8efc093..10ac2c9f4 100644
--- a/lib/lsan/lsan_thread.cc
+++ b/lib/lsan/lsan_thread.cc
@@ -79,7 +79,7 @@ void ThreadContext::OnFinished() {
 
 u32 ThreadCreate(u32 parent_tid, uptr user_id, bool detached) {
   return thread_registry->CreateThread(user_id, detached, parent_tid,
-                                       /* arg */ 0);
+                                       /* arg */ nullptr);
 }
 
 void ThreadStart(u32 tid, uptr os_id) {
@@ -99,9 +99,9 @@ void ThreadFinish() {
 }
 
 ThreadContext *CurrentThreadContext() {
-  if (!thread_registry) return 0;
+  if (!thread_registry) return nullptr;
   if (GetCurrentThread() == kInvalidTid)
-    return 0;
+    return nullptr;
   // No lock needed when getting current thread.
   return (ThreadContext *)thread_registry->GetThreadLocked(GetCurrentThread());
 }
@@ -120,7 +120,7 @@ u32 ThreadTid(uptr uid) {
 
 void ThreadJoin(u32 tid) {
   CHECK_NE(tid, kInvalidTid);
-  thread_registry->JoinThread(tid, /* arg */0);
+  thread_registry->JoinThread(tid, /* arg */nullptr);
 }
 
 void EnsureMainThreadIDIsCorrect() {
@@ -157,4 +157,4 @@ void UnlockThreadRegistry() {
   thread_registry->Unlock();
 }
 
-}  // namespace __lsan
+} // namespace __lsan
diff --git a/lib/msan/msan.cc b/lib/msan/msan.cc
index 12a141bf4..87f2cdf2e 100644
--- a/lib/msan/msan.cc
+++ b/lib/msan/msan.cc
@@ -223,9 +223,9 @@ void GetStackTrace(BufferedStackTrace *stack, uptr max_s, uptr pc, uptr bp,
   if (!t || !StackTrace::WillUseFastUnwind(request_fast_unwind)) {
     // Block reports from our interceptors during _Unwind_Backtrace.
     SymbolizerScope sym_scope;
-    return stack->Unwind(max_s, pc, bp, 0, 0, 0, request_fast_unwind);
+    return stack->Unwind(max_s, pc, bp, nullptr, 0, 0, request_fast_unwind);
   }
-  stack->Unwind(max_s, pc, bp, 0, t->stack_top(), t->stack_bottom(),
+  stack->Unwind(max_s, pc, bp, nullptr, t->stack_top(), t->stack_bottom(),
                 request_fast_unwind);
 }
 
@@ -305,7 +305,7 @@ u32 ChainOrigin(u32 id, StackTrace *stack) {
   return chained.raw_id();
 }
 
-}  // namespace __msan
+} // namespace __msan
 
 // Interface.
 
@@ -417,7 +417,7 @@ void __msan_init() {
 
   MsanAllocatorInit();
 
-  MsanThread *main_thread = MsanThread::Create(0, 0);
+  MsanThread *main_thread = MsanThread::Create(nullptr, nullptr);
   SetCurrentThread(main_thread);
   main_thread->ThreadStart();
 
@@ -641,4 +641,4 @@ void __sanitizer_print_stack_trace() {
   GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());
   stack.Print();
 }
-}  // extern "C"
+} // extern "C"
diff --git a/lib/msan/msan_allocator.cc b/lib/msan/msan_allocator.cc
index 006d993f0..865a4586b 100644
--- a/lib/msan/msan_allocator.cc
+++ b/lib/msan/msan_allocator.cc
@@ -165,7 +165,7 @@ void MsanDeallocate(StackTrace *stack, void *p) {
 void *MsanCalloc(StackTrace *stack, uptr nmemb, uptr size) {
   if (CallocShouldReturnNullDueToOverflow(size, nmemb))
     return allocator.ReturnNullOrDie();
-  return MsanReallocate(stack, 0, nmemb * size, sizeof(u64), true);
+  return MsanReallocate(stack, nullptr, nmemb * size, sizeof(u64), true);
 }
 
 void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,
@@ -174,7 +174,7 @@ void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,
     return MsanAllocate(stack, new_size, alignment, zeroise);
   if (!new_size) {
     MsanDeallocate(stack, old_p);
-    return 0;
+    return nullptr;
   }
   Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(old_p));
   uptr old_size = meta->requested_size;
@@ -204,14 +204,14 @@ void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,
 }
 
 static uptr AllocationSize(const void *p) {
-  if (p == 0) return 0;
+  if (!p) return 0;
   const void *beg = allocator.GetBlockBegin(p);
   if (beg != p) return 0;
   Metadata *b = (Metadata *)allocator.GetMetaData(p);
   return b->requested_size;
 }
 
-}  // namespace __msan
+} // namespace __msan
 
 using namespace __msan;
 
diff --git a/lib/msan/msan_chained_origin_depot.cc b/lib/msan/msan_chained_origin_depot.cc
index c21e8e827..e2796fd46 100644
--- a/lib/msan/msan_chained_origin_depot.cc
+++ b/lib/msan/msan_chained_origin_depot.cc
@@ -28,12 +28,15 @@ struct ChainedOriginDepotNode {
   u32 prev_id;
 
   typedef ChainedOriginDepotDesc args_type;
+
   bool eq(u32 hash, const args_type &args) const {
     return here_id == args.here_id && prev_id == args.prev_id;
   }
+
   static uptr storage_size(const args_type &args) {
     return sizeof(ChainedOriginDepotNode);
   }
+
   /* This is murmur2 hash for the 64->32 bit case.
      It does not behave all that well because the keys have a very biased
      distribution (I've seen 7-element buckets with the table only 14% full).
@@ -76,19 +79,22 @@ struct ChainedOriginDepotNode {
     here_id = args.here_id;
     prev_id = args.prev_id;
   }
+
   args_type load() const {
     args_type ret = {here_id, prev_id};
     return ret;
   }
+
   struct Handle {
     ChainedOriginDepotNode *node_;
-    Handle() : node_(0) {}
+    Handle() : node_(nullptr) {}
     explicit Handle(ChainedOriginDepotNode *node) : node_(node) {}
     bool valid() { return node_; }
     u32 id() { return node_->id; }
     int here_id() { return node_->here_id; }
     int prev_id() { return node_->prev_id; }
   };
+
   Handle get_handle() { return Handle(this); }
 
   typedef Handle handle_type;
@@ -123,4 +129,4 @@ void ChainedOriginDepotUnlockAll() {
   chainedOriginDepot.UnlockAll();
 }
 
-}  // namespace __msan
+} // namespace __msan
diff --git a/lib/msan/msan_interceptors.cc b/lib/msan/msan_interceptors.cc
index c42885815..f363c2695 100644
--- a/lib/msan/msan_interceptors.cc
+++ b/lib/msan/msan_interceptors.cc
@@ -166,7 +166,7 @@ INTERCEPTOR(int, posix_memalign, void **memptr, SIZE_T alignment, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
   CHECK_EQ(alignment & (alignment - 1), 0);
   CHECK_NE(memptr, 0);
-  *memptr = MsanReallocate(&stack, 0, size, alignment, false);
+  *memptr = MsanReallocate(&stack, nullptr, size, alignment, false);
   CHECK_NE(*memptr, 0);
   __msan_unpoison(memptr, sizeof(*memptr));
   return 0;
@@ -176,7 +176,7 @@ INTERCEPTOR(int, posix_memalign, void **memptr, SIZE_T alignment, SIZE_T size) {
 INTERCEPTOR(void *, memalign, SIZE_T boundary, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
   CHECK_EQ(boundary & (boundary - 1), 0);
-  void *ptr = MsanReallocate(&stack, 0, size, boundary, false);
+  void *ptr = MsanReallocate(&stack, nullptr, size, boundary, false);
   return ptr;
 }
 #define MSAN_MAYBE_INTERCEPT_MEMALIGN INTERCEPT_FUNCTION(memalign)
@@ -187,21 +187,21 @@ INTERCEPTOR(void *, memalign, SIZE_T boundary, SIZE_T size) {
 INTERCEPTOR(void *, aligned_alloc, SIZE_T boundary, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
   CHECK_EQ(boundary & (boundary - 1), 0);
-  void *ptr = MsanReallocate(&stack, 0, size, boundary, false);
+  void *ptr = MsanReallocate(&stack, nullptr, size, boundary, false);
   return ptr;
 }
 
 INTERCEPTOR(void *, __libc_memalign, SIZE_T boundary, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
   CHECK_EQ(boundary & (boundary - 1), 0);
-  void *ptr = MsanReallocate(&stack, 0, size, boundary, false);
+  void *ptr = MsanReallocate(&stack, nullptr, size, boundary, false);
   DTLS_on_libc_memalign(ptr, size * boundary);
   return ptr;
 }
 
 INTERCEPTOR(void *, valloc, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
-  void *ptr = MsanReallocate(&stack, 0, size, GetPageSizeCached(), false);
+  void *ptr = MsanReallocate(&stack, nullptr, size, GetPageSizeCached(), false);
   return ptr;
 }
 
@@ -214,7 +214,7 @@ INTERCEPTOR(void *, pvalloc, SIZE_T size) {
     // pvalloc(0) should allocate one page.
     size = PageSize;
   }
-  void *ptr = MsanReallocate(&stack, 0, size, PageSize, false);
+  void *ptr = MsanReallocate(&stack, nullptr, size, PageSize, false);
   return ptr;
 }
 #define MSAN_MAYBE_INTERCEPT_PVALLOC INTERCEPT_FUNCTION(pvalloc)
@@ -224,14 +224,14 @@ INTERCEPTOR(void *, pvalloc, SIZE_T size) {
 
 INTERCEPTOR(void, free, void *ptr) {
   GET_MALLOC_STACK_TRACE;
-  if (ptr == 0) return;
+  if (!ptr) return;
   MsanDeallocate(&stack, ptr);
 }
 
 #if !SANITIZER_FREEBSD
 INTERCEPTOR(void, cfree, void *ptr) {
   GET_MALLOC_STACK_TRACE;
-  if (ptr == 0) return;
+  if (!ptr) return;
   MsanDeallocate(&stack, ptr);
 }
 #define MSAN_MAYBE_INTERCEPT_CFREE INTERCEPT_FUNCTION(cfree)
@@ -1000,7 +1000,7 @@ INTERCEPTOR(void *, realloc, void *ptr, SIZE_T size) {
 
 INTERCEPTOR(void *, malloc, SIZE_T size) {
   GET_MALLOC_STACK_TRACE;
-  return MsanReallocate(&stack, 0, size, sizeof(u64), false);
+  return MsanReallocate(&stack, nullptr, size, sizeof(u64), false);
 }
 
 void __msan_allocated_memory(const void *data, uptr size) {
@@ -1029,7 +1029,7 @@ INTERCEPTOR(void *, mmap, void *addr, SIZE_T length, int prot, int flags,
       *__errno_location() = errno_EINVAL;
       return (void *)-1;
     } else {
-      addr = 0;
+      addr = nullptr;
     }
   }
   void *res = REAL(mmap)(addr, length, prot, flags, fd, offset);
@@ -1047,7 +1047,7 @@ INTERCEPTOR(void *, mmap64, void *addr, SIZE_T length, int prot, int flags,
       *__errno_location() = errno_EINVAL;
       return (void *)-1;
     } else {
-      addr = 0;
+      addr = nullptr;
     }
   }
   void *res = REAL(mmap64)(addr, length, prot, flags, fd, offset);
@@ -1083,7 +1083,7 @@ INTERCEPTOR(int, dladdr, void *addr, dlinfo *info) {
 INTERCEPTOR(char *, dlerror, int fake) {
   ENSURE_MSAN_INITED();
   char *res = REAL(dlerror)(fake);
-  if (res != 0) __msan_unpoison(res, REAL(strlen)(res) + 1);
+  if (res) __msan_unpoison(res, REAL(strlen)(res) + 1);
   return res;
 }
 
@@ -1180,7 +1180,7 @@ INTERCEPTOR(int, sigaction, int signo, const __sanitizer_sigaction *act,
     CHECK_LT(signo, kMaxSignals);
     uptr old_cb = atomic_load(&sigactions[signo], memory_order_relaxed);
     __sanitizer_sigaction new_act;
-    __sanitizer_sigaction *pnew_act = act ? &new_act : 0;
+    __sanitizer_sigaction *pnew_act = act ? &new_act : nullptr;
     if (act) {
       REAL(memcpy)(pnew_act, act, sizeof(__sanitizer_sigaction));
       uptr cb = (uptr)pnew_act->sigaction;
@@ -1237,7 +1237,7 @@ INTERCEPTOR(int, pthread_create, void *th, void *attr, void *(*callback)(void*),
             void * param) {
   ENSURE_MSAN_INITED(); // for GetTlsSize()
   __sanitizer_pthread_attr_t myattr;
-  if (attr == 0) {
+  if (!attr) {
     pthread_attr_init(&myattr);
     attr = &myattr;
   }
@@ -1376,7 +1376,7 @@ int OnExit() {
   return 0;
 }
 
-}  // namespace __msan
+} // namespace __msan
 
 // A version of CHECK_UNPOISONED using a saved scope value. Used in common
 // interceptors.
@@ -1634,4 +1634,4 @@ void InitializeInterceptors() {
 
   inited = 1;
 }
-}  // namespace __msan
+} // namespace __msan
diff --git a/lib/msan/msan_linux.cc b/lib/msan/msan_linux.cc
index 7f6cb75ff..2888eb528 100644
--- a/lib/msan/msan_linux.cc
+++ b/lib/msan/msan_linux.cc
@@ -56,7 +56,7 @@ static bool CheckMemoryRangeAvailability(uptr beg, uptr size) {
 static bool ProtectMemoryRange(uptr beg, uptr size, const char *name) {
   if (size > 0) {
     void *addr = MmapNoAccess(beg, size, name);
-    if (beg == 0 && addr != 0) {
+    if (beg == 0 && addr) {
       // Depending on the kernel configuration, we may not be able to protect
       // the page at address zero.
       uptr gap = 16 * GetPageSizeCached();
@@ -204,6 +204,6 @@ void MsanTSDDtor(void *tsd) {
   MsanThread::TSDDtor(tsd);
 }
 
-}  // namespace __msan
+} // namespace __msan
 
-#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX
+#endif // SANITIZER_FREEBSD || SANITIZER_LINUX
diff --git a/lib/msan/msan_thread.h b/lib/msan/msan_thread.h
index bc605b89a..ed22e67ed 100644
--- a/lib/msan/msan_thread.h
+++ b/lib/msan/msan_thread.h
@@ -32,7 +32,7 @@ class MsanThread {
   uptr stack_bottom() { return stack_bottom_; }
   uptr tls_begin() { return tls_begin_; }
   uptr tls_end() { return tls_end_; }
-  bool IsMainThread() { return start_routine_ == 0; }
+  bool IsMainThread() { return start_routine_ == nullptr; }
 
   bool AddrIsInStack(uptr addr) {
     return addr >= stack_bottom_ && addr < stack_top_;
diff --git a/lib/safestack/safestack.cc b/lib/safestack/safestack.cc
index 504bd3cd0..5254462d9 100644
--- a/lib/safestack/safestack.cc
+++ b/lib/safestack/safestack.cc
@@ -171,7 +171,7 @@ INTERCEPTOR(int, pthread_create, pthread_t *thread,
   size_t size = 0;
   size_t guard = 0;
 
-  if (attr != NULL) {
+  if (attr) {
     pthread_attr_getstacksize(attr, &size);
     pthread_attr_getguardsize(attr, &guard);
   } else {