Update compiler-rt to trunk r224034. This brings a number of new

builtins, and also the various sanitizers.  Support for these will be
added in a later commit.

1 files changed, 924 insertions, 0 deletions

diff --git a/contrib/compiler-rt/lib/asan/asan_interceptors.cc b/contrib/compiler-rt/lib/asan/asan_interceptors.cc
new file mode 100644
index 000000000000..910cd3addcb0
--- /dev/null
+++ b/contrib/compiler-rt/lib/asan/asan_interceptors.cc
@@ -0,0 +1,924 @@
+//===-- asan_interceptors.cc ----------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// Intercept various libc functions.
+//===----------------------------------------------------------------------===//
+#include "asan_interceptors.h"
+
+#include "asan_allocator.h"
+#include "asan_internal.h"
+#include "asan_mapping.h"
+#include "asan_poisoning.h"
+#include "asan_report.h"
+#include "asan_stack.h"
+#include "asan_stats.h"
+#include "asan_suppressions.h"
+#include "sanitizer_common/sanitizer_libc.h"
+
+namespace __asan {
+
+// Return true if we can quickly decide that the region is unpoisoned.
+static inline bool QuickCheckForUnpoisonedRegion(uptr beg, uptr size) {
+  if (size == 0) return true;
+  if (size <= 32)
+    return !AddressIsPoisoned(beg) &&
+           !AddressIsPoisoned(beg + size - 1) &&
+           !AddressIsPoisoned(beg + size / 2);
+  return false;
+}
+
+struct AsanInterceptorContext {
+  const char *interceptor_name;
+};
+
+// We implement ACCESS_MEMORY_RANGE, ASAN_READ_RANGE,
+// and ASAN_WRITE_RANGE as macro instead of function so
+// that no extra frames are created, and stack trace contains
+// relevant information only.
+// We check all shadow bytes.
+#define ACCESS_MEMORY_RANGE(ctx, offset, size, isWrite) do {            \
+    uptr __offset = (uptr)(offset);                                     \
+    uptr __size = (uptr)(size);                                         \
+    uptr __bad = 0;                                                     \
+    if (__offset > __offset + __size) {                                 \
+      GET_STACK_TRACE_FATAL_HERE;                                       \
+      ReportStringFunctionSizeOverflow(__offset, __size, &stack);       \
+    }                                                                   \
+    if (!QuickCheckForUnpoisonedRegion(__offset, __size) &&             \
+        (__bad = __asan_region_is_poisoned(__offset, __size))) {        \
+      AsanInterceptorContext *_ctx = (AsanInterceptorContext *)ctx;     \
+      bool suppressed = false;                                          \
+      if (_ctx) {                                                       \
+        suppressed = IsInterceptorSuppressed(_ctx->interceptor_name);   \
+        if (!suppressed && HaveStackTraceBasedSuppressions()) {         \
+          GET_STACK_TRACE_FATAL_HERE;                                   \
+          suppressed = IsStackTraceSuppressed(&stack);                  \
+        }                                                               \
+      }                                                                 \
+      if (!suppressed) {                                                \
+        GET_CURRENT_PC_BP_SP;                                           \
+        __asan_report_error(pc, bp, sp, __bad, isWrite, __size);        \
+      }                                                                 \
+    }                                                                   \
+  } while (0)
+
+#define ASAN_READ_RANGE(ctx, offset, size) \
+  ACCESS_MEMORY_RANGE(ctx, offset, size, false)
+#define ASAN_WRITE_RANGE(ctx, offset, size) \
+  ACCESS_MEMORY_RANGE(ctx, offset, size, true)
+
+// Behavior of functions like "memcpy" or "strcpy" is undefined
+// if memory intervals overlap. We report error in this case.
+// Macro is used to avoid creation of new frames.
+static inline bool RangesOverlap(const char *offset1, uptr length1,
+                                 const char *offset2, uptr length2) {
+  return !((offset1 + length1 <= offset2) || (offset2 + length2 <= offset1));
+}
+#define CHECK_RANGES_OVERLAP(name, _offset1, length1, _offset2, length2) do { \
+  const char *offset1 = (const char*)_offset1; \
+  const char *offset2 = (const char*)_offset2; \
+  if (RangesOverlap(offset1, length1, offset2, length2)) { \
+    GET_STACK_TRACE_FATAL_HERE; \
+    ReportStringFunctionMemoryRangesOverlap(name, offset1, length1, \
+                                            offset2, length2, &stack); \
+  } \
+} while (0)
+
+static inline uptr MaybeRealStrnlen(const char *s, uptr maxlen) {
+#if ASAN_INTERCEPT_STRNLEN
+  if (REAL(strnlen) != 0) {
+    return REAL(strnlen)(s, maxlen);
+  }
+#endif
+  return internal_strnlen(s, maxlen);
+}
+
+void SetThreadName(const char *name) {
+  AsanThread *t = GetCurrentThread();
+  if (t)
+    asanThreadRegistry().SetThreadName(t->tid(), name);
+}
+
+int OnExit() {
+  // FIXME: ask frontend whether we need to return failure.
+  return 0;
+}
+
+}  // namespace __asan
+
+// ---------------------- Wrappers ---------------- {{{1
+using namespace __asan;  // NOLINT
+
+DECLARE_REAL_AND_INTERCEPTOR(void *, malloc, uptr)
+DECLARE_REAL_AND_INTERCEPTOR(void, free, void *)
+
+#if !SANITIZER_MAC
+#define ASAN_INTERCEPT_FUNC(name)                                        \
+  do {                                                                   \
+    if ((!INTERCEPT_FUNCTION(name) || !REAL(name)))                      \
+      VReport(1, "AddressSanitizer: failed to intercept '" #name "'\n"); \
+  } while (0)
+#else
+// OS X interceptors don't need to be initialized with INTERCEPT_FUNCTION.
+#define ASAN_INTERCEPT_FUNC(name)
+#endif  // SANITIZER_MAC
+
+#define ASAN_INTERCEPTOR_ENTER(ctx, func)                                      \
+  AsanInterceptorContext _ctx = {#func};                                       \
+  ctx = (void *)&_ctx;                                                         \
+  (void) ctx;                                                                  \
+
+#define COMMON_INTERCEPT_FUNCTION(name) ASAN_INTERCEPT_FUNC(name)
+#define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size) \
+  ASAN_WRITE_RANGE(ctx, ptr, size)
+#define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size) \
+  ASAN_READ_RANGE(ctx, ptr, size)
+#define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)                               \
+  do {                                                                         \
+    if (asan_init_is_running)                                                  \
+      return REAL(func)(__VA_ARGS__);                                          \
+    ASAN_INTERCEPTOR_ENTER(ctx, func);                                         \
+    if (SANITIZER_MAC && UNLIKELY(!asan_inited))                               \
+      return REAL(func)(__VA_ARGS__);                                          \
+    ENSURE_ASAN_INITED();                                                      \
+  } while (false)
+#define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
+  do {                                         \
+  } while (false)
+#define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \
+  do {                                         \
+  } while (false)
+#define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \
+  do {                                                      \
+  } while (false)
+#define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) SetThreadName(name)
+// Should be asanThreadRegistry().SetThreadNameByUserId(thread, name)
+// But asan does not remember UserId's for threads (pthread_t);
+// and remembers all ever existed threads, so the linear search by UserId
+// can be slow.
+#define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
+  do {                                                         \
+  } while (false)
+#define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)
+#define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
+#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, res) CovUpdateMapping()
+#define COMMON_INTERCEPTOR_LIBRARY_UNLOADED() CovUpdateMapping()
+#define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (!asan_inited)
+#include "sanitizer_common/sanitizer_common_interceptors.inc"
+
+// Syscall interceptors don't have contexts, we don't support suppressions
+// for them.
+#define COMMON_SYSCALL_PRE_READ_RANGE(p, s) ASAN_READ_RANGE(nullptr, p, s)
+#define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) ASAN_WRITE_RANGE(nullptr, p, s)
+#define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
+  do {                                       \
+    (void)(p);                               \
+    (void)(s);                               \
+  } while (false)
+#define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) \
+  do {                                        \
+    (void)(p);                                \
+    (void)(s);                                \
+  } while (false)
+#include "sanitizer_common/sanitizer_common_syscalls.inc"
+
+struct ThreadStartParam {
+  atomic_uintptr_t t;
+  atomic_uintptr_t is_registered;
+};
+
+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)
+    internal_sched_yield();
+  SetCurrentThread(t);
+  return t->ThreadStart(GetTid(), &param->is_registered);
+}
+
+#if ASAN_INTERCEPT_PTHREAD_CREATE
+INTERCEPTOR(int, pthread_create, void *thread,
+    void *attr, void *(*start_routine)(void*), void *arg) {
+  EnsureMainThreadIDIsCorrect();
+  // Strict init-order checking is thread-hostile.
+  if (flags()->strict_init_order)
+    StopInitOrderChecking();
+  GET_STACK_TRACE_THREAD;
+  int detached = 0;
+  if (attr != 0)
+    REAL(pthread_attr_getdetachstate)(attr, &detached);
+  ThreadStartParam param;
+  atomic_store(&param.t, 0, memory_order_relaxed);
+  atomic_store(&param.is_registered, 0, memory_order_relaxed);
+  int result = REAL(pthread_create)(thread, attr, asan_thread_start, &param);
+  if (result == 0) {
+    u32 current_tid = GetCurrentTidOrInvalid();
+    AsanThread *t =
+        AsanThread::Create(start_routine, arg, current_tid, &stack, detached);
+    atomic_store(&param.t, reinterpret_cast<uptr>(t), memory_order_release);
+    // Wait until the AsanThread object is initialized and the ThreadRegistry
+    // entry is in "started" state. One reason for this is that after this
+    // interceptor exits, the child thread's stack may be the only thing holding
+    // the |arg| pointer. This may cause LSan to report a leak if leak checking
+    // happens at a point when the interceptor has already exited, but the stack
+    // range for the child thread is not yet known.
+    while (atomic_load(&param.is_registered, memory_order_acquire) == 0)
+      internal_sched_yield();
+  }
+  return result;
+}
+#endif  // ASAN_INTERCEPT_PTHREAD_CREATE
+
+#if ASAN_INTERCEPT_SIGNAL_AND_SIGACTION
+
+#if SANITIZER_ANDROID
+INTERCEPTOR(void*, bsd_signal, int signum, void *handler) {
+  if (!AsanInterceptsSignal(signum) ||
+      common_flags()->allow_user_segv_handler) {
+    return REAL(bsd_signal)(signum, handler);
+  }
+  return 0;
+}
+#else
+INTERCEPTOR(void*, signal, int signum, void *handler) {
+  if (!AsanInterceptsSignal(signum) ||
+      common_flags()->allow_user_segv_handler) {
+    return REAL(signal)(signum, handler);
+  }
+  return 0;
+}
+#endif
+
+INTERCEPTOR(int, sigaction, int signum, const struct sigaction *act,
+                            struct sigaction *oldact) {
+  if (!AsanInterceptsSignal(signum) ||
+      common_flags()->allow_user_segv_handler) {
+    return REAL(sigaction)(signum, act, oldact);
+  }
+  return 0;
+}
+
+namespace __sanitizer {
+int real_sigaction(int signum, const void *act, void *oldact) {
+  return REAL(sigaction)(signum, (const struct sigaction *)act,
+                         (struct sigaction *)oldact);
+}
+}  // namespace __sanitizer
+
+#elif SANITIZER_POSIX
+// We need to have defined REAL(sigaction) on posix systems.
+DEFINE_REAL(int, sigaction, int signum, const struct sigaction *act,
+    struct sigaction *oldact)
+#endif  // ASAN_INTERCEPT_SIGNAL_AND_SIGACTION
+
+#if ASAN_INTERCEPT_SWAPCONTEXT
+static void ClearShadowMemoryForContextStack(uptr stack, uptr ssize) {
+  // Align to page size.
+  uptr PageSize = GetPageSizeCached();
+  uptr bottom = stack & ~(PageSize - 1);
+  ssize += stack - bottom;
+  ssize = RoundUpTo(ssize, PageSize);
+  static const uptr kMaxSaneContextStackSize = 1 << 22;  // 4 Mb
+  if (ssize && ssize <= kMaxSaneContextStackSize) {
+    PoisonShadow(bottom, ssize, 0);
+  }
+}
+
+INTERCEPTOR(int, swapcontext, struct ucontext_t *oucp,
+            struct ucontext_t *ucp) {
+  static bool reported_warning = false;
+  if (!reported_warning) {
+    Report("WARNING: ASan doesn't fully support makecontext/swapcontext "
+           "functions and may produce false positives in some cases!\n");
+    reported_warning = true;
+  }
+  // Clear shadow memory for new context (it may share stack
+  // with current context).
+  uptr stack, ssize;
+  ReadContextStack(ucp, &stack, &ssize);
+  ClearShadowMemoryForContextStack(stack, ssize);
+  int res = REAL(swapcontext)(oucp, ucp);
+  // swapcontext technically does not return, but program may swap context to
+  // "oucp" later, that would look as if swapcontext() returned 0.
+  // We need to clear shadow for ucp once again, as it may be in arbitrary
+  // state.
+  ClearShadowMemoryForContextStack(stack, ssize);
+  return res;
+}
+#endif  // ASAN_INTERCEPT_SWAPCONTEXT
+
+INTERCEPTOR(void, longjmp, void *env, int val) {
+  __asan_handle_no_return();
+  REAL(longjmp)(env, val);
+}
+
+#if ASAN_INTERCEPT__LONGJMP
+INTERCEPTOR(void, _longjmp, void *env, int val) {
+  __asan_handle_no_return();
+  REAL(_longjmp)(env, val);
+}
+#endif
+
+#if ASAN_INTERCEPT_SIGLONGJMP
+INTERCEPTOR(void, siglongjmp, void *env, int val) {
+  __asan_handle_no_return();
+  REAL(siglongjmp)(env, val);
+}
+#endif
+
+#if ASAN_INTERCEPT___CXA_THROW
+INTERCEPTOR(void, __cxa_throw, void *a, void *b, void *c) {
+  CHECK(REAL(__cxa_throw));
+  __asan_handle_no_return();
+  REAL(__cxa_throw)(a, b, c);
+}
+#endif
+
+#if SANITIZER_WINDOWS
+INTERCEPTOR_WINAPI(void, RaiseException, void *a, void *b, void *c, void *d) {
+  CHECK(REAL(RaiseException));
+  __asan_handle_no_return();
+  REAL(RaiseException)(a, b, c, d);
+}
+
+INTERCEPTOR(int, _except_handler3, void *a, void *b, void *c, void *d) {
+  CHECK(REAL(_except_handler3));
+  __asan_handle_no_return();
+  return REAL(_except_handler3)(a, b, c, d);
+}
+
+#if ASAN_DYNAMIC
+// This handler is named differently in -MT and -MD CRTs.
+#define _except_handler4 _except_handler4_common
+#endif
+INTERCEPTOR(int, _except_handler4, void *a, void *b, void *c, void *d) {
+  CHECK(REAL(_except_handler4));
+  __asan_handle_no_return();
+  return REAL(_except_handler4)(a, b, c, d);
+}
+#endif
+
+static inline int CharCmp(unsigned char c1, unsigned char c2) {
+  return (c1 == c2) ? 0 : (c1 < c2) ? -1 : 1;
+}
+
+INTERCEPTOR(int, memcmp, const void *a1, const void *a2, uptr size) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, memcmp);
+  if (UNLIKELY(!asan_inited)) return internal_memcmp(a1, a2, size);
+  ENSURE_ASAN_INITED();
+  if (flags()->replace_intrin) {
+    if (flags()->strict_memcmp) {
+      // Check the entire regions even if the first bytes of the buffers are
+      // different.
+      ASAN_READ_RANGE(ctx, a1, size);
+      ASAN_READ_RANGE(ctx, a2, size);
+      // Fallthrough to REAL(memcmp) below.
+    } else {
+      unsigned char c1 = 0, c2 = 0;
+      const unsigned char *s1 = (const unsigned char*)a1;
+      const unsigned char *s2 = (const unsigned char*)a2;
+      uptr i;
+      for (i = 0; i < size; i++) {
+        c1 = s1[i];
+        c2 = s2[i];
+        if (c1 != c2) break;
+      }
+      ASAN_READ_RANGE(ctx, s1, Min(i + 1, size));
+      ASAN_READ_RANGE(ctx, s2, Min(i + 1, size));
+      return CharCmp(c1, c2);
+    }
+  }
+  return REAL(memcmp(a1, a2, size));
+}
+
+// memcpy is called during __asan_init() from the internals of printf(...).
+// We do not treat memcpy with to==from as a bug.
+// See http://llvm.org/bugs/show_bug.cgi?id=11763.
+#define ASAN_MEMCPY_IMPL(ctx, to, from, size) do {                             \
+    if (UNLIKELY(!asan_inited)) return internal_memcpy(to, from, size);        \
+    if (asan_init_is_running) {                                                \
+      return REAL(memcpy)(to, from, size);                                     \
+    }                                                                          \
+    ENSURE_ASAN_INITED();                                                      \
+    if (flags()->replace_intrin) {                                             \
+      if (to != from) {                                                        \
+        CHECK_RANGES_OVERLAP("memcpy", to, size, from, size);                  \
+      }                                                                        \
+      ASAN_READ_RANGE(ctx, from, size);                                        \
+      ASAN_WRITE_RANGE(ctx, to, size);                                         \
+    }                                                                          \
+    return REAL(memcpy)(to, from, size);                                       \
+  } while (0)
+
+
+void *__asan_memcpy(void *to, const void *from, uptr size) {
+  ASAN_MEMCPY_IMPL(nullptr, to, from, size);
+}
+
+// memset is called inside Printf.
+#define ASAN_MEMSET_IMPL(ctx, block, c, size) do {                             \
+    if (UNLIKELY(!asan_inited)) return internal_memset(block, c, size);        \
+    if (asan_init_is_running) {                                                \
+      return REAL(memset)(block, c, size);                                     \
+    }                                                                          \
+    ENSURE_ASAN_INITED();                                                      \
+    if (flags()->replace_intrin) {                                             \
+      ASAN_WRITE_RANGE(ctx, block, size);                                      \
+    }                                                                          \
+    return REAL(memset)(block, c, size);                                       \
+  } while (0)
+
+void *__asan_memset(void *block, int c, uptr size) {
+  ASAN_MEMSET_IMPL(nullptr, block, c, size);
+}
+
+#define ASAN_MEMMOVE_IMPL(ctx, to, from, size) do {                            \
+    if (UNLIKELY(!asan_inited))                                                \
+      return internal_memmove(to, from, size);                                 \
+    ENSURE_ASAN_INITED();                                                      \
+    if (flags()->replace_intrin) {                                             \
+      ASAN_READ_RANGE(ctx, from, size);                                        \
+      ASAN_WRITE_RANGE(ctx, to, size);                                         \
+    }                                                                          \
+    return internal_memmove(to, from, size);                                   \
+  } while (0)
+
+void *__asan_memmove(void *to, const void *from, uptr size) {
+  ASAN_MEMMOVE_IMPL(nullptr, to, from, size);
+}
+
+INTERCEPTOR(void*, memmove, void *to, const void *from, uptr size) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, memmove);
+  ASAN_MEMMOVE_IMPL(ctx, to, from, size);
+}
+
+INTERCEPTOR(void*, memcpy, void *to, const void *from, uptr size) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, memcpy);
+#if !SANITIZER_MAC
+  ASAN_MEMCPY_IMPL(ctx, to, from, size);
+#else
+  // At least on 10.7 and 10.8 both memcpy() and memmove() are being replaced
+  // with WRAP(memcpy). As a result, false positives are reported for memmove()
+  // calls. If we just disable error reporting with
+  // ASAN_OPTIONS=replace_intrin=0, memmove() is still replaced with
+  // internal_memcpy(), which may lead to crashes, see
+  // http://llvm.org/bugs/show_bug.cgi?id=16362.
+  ASAN_MEMMOVE_IMPL(ctx, to, from, size);
+#endif  // !SANITIZER_MAC
+}
+
+INTERCEPTOR(void*, memset, void *block, int c, uptr size) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, memset);
+  ASAN_MEMSET_IMPL(ctx, block, c, size);
+}
+
+INTERCEPTOR(char*, strchr, const char *str, int c) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, strchr);
+  if (UNLIKELY(!asan_inited)) return internal_strchr(str, c);
+  // strchr is called inside create_purgeable_zone() when MallocGuardEdges=1 is
+  // used.
+  if (asan_init_is_running) {
+    return REAL(strchr)(str, c);
+  }
+  ENSURE_ASAN_INITED();
+  char *result = REAL(strchr)(str, c);
+  if (flags()->replace_str) {
+    uptr bytes_read = (result ? result - str : REAL(strlen)(str)) + 1;
+    ASAN_READ_RANGE(ctx, str, bytes_read);
+  }
+  return result;
+}
+
+#if ASAN_INTERCEPT_INDEX
+# if ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX
+INTERCEPTOR(char*, index, const char *string, int c)
+  ALIAS(WRAPPER_NAME(strchr));
+# else
+#  if SANITIZER_MAC
+DECLARE_REAL(char*, index, const char *string, int c)
+OVERRIDE_FUNCTION(index, strchr);
+#  else
+DEFINE_REAL(char*, index, const char *string, int c)
+#  endif
+# endif
+#endif  // ASAN_INTERCEPT_INDEX
+
+// For both strcat() and strncat() we need to check the validity of |to|
+// argument irrespective of the |from| length.
+INTERCEPTOR(char*, strcat, char *to, const char *from) {  // NOLINT
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, strcat);  // NOLINT
+  ENSURE_ASAN_INITED();
+  if (flags()->replace_str) {
+    uptr from_length = REAL(strlen)(from);
+    ASAN_READ_RANGE(ctx, from, from_length + 1);
+    uptr to_length = REAL(strlen)(to);
+    ASAN_READ_RANGE(ctx, to, to_length);
+    ASAN_WRITE_RANGE(ctx, to + to_length, from_length + 1);
+    // If the copying actually happens, the |from| string should not overlap
+    // with the resulting string starting at |to|, which has a length of
+    // to_length + from_length + 1.
+    if (from_length > 0) {
+      CHECK_RANGES_OVERLAP("strcat", to, from_length + to_length + 1,
+                           from, from_length + 1);
+    }
+  }
+  return REAL(strcat)(to, from);  // NOLINT
+}
+
+INTERCEPTOR(char*, strncat, char *to, const char *from, uptr size) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, strncat);
+  ENSURE_ASAN_INITED();
+  if (flags()->replace_str) {
+    uptr from_length = MaybeRealStrnlen(from, size);
+    uptr copy_length = Min(size, from_length + 1);
+    ASAN_READ_RANGE(ctx, from, copy_length);
+    uptr to_length = REAL(strlen)(to);
+    ASAN_READ_RANGE(ctx, to, to_length);
+    ASAN_WRITE_RANGE(ctx, to + to_length, from_length + 1);
+    if (from_length > 0) {
+      CHECK_RANGES_OVERLAP("strncat", to, to_length + copy_length + 1,
+                           from, copy_length);
+    }
+  }
+  return REAL(strncat)(to, from, size);
+}
+
+INTERCEPTOR(char*, strcpy, char *to, const char *from) {  // NOLINT
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, strcpy);  // NOLINT
+#if SANITIZER_MAC
+  if (UNLIKELY(!asan_inited)) return REAL(strcpy)(to, from);  // NOLINT
+#endif
+  // strcpy is called from malloc_default_purgeable_zone()
+  // in __asan::ReplaceSystemAlloc() on Mac.
+  if (asan_init_is_running) {
+    return REAL(strcpy)(to, from);  // NOLINT
+  }
+  ENSURE_ASAN_INITED();
+  if (flags()->replace_str) {
+    uptr from_size = REAL(strlen)(from) + 1;
+    CHECK_RANGES_OVERLAP("strcpy", to, from_size, from, from_size);
+    ASAN_READ_RANGE(ctx, from, from_size);
+    ASAN_WRITE_RANGE(ctx, to, from_size);
+  }
+  return REAL(strcpy)(to, from);  // NOLINT
+}
+
+#if ASAN_INTERCEPT_STRDUP
+INTERCEPTOR(char*, strdup, const char *s) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, strdup);
+  if (UNLIKELY(!asan_inited)) return internal_strdup(s);
+  ENSURE_ASAN_INITED();
+  uptr length = REAL(strlen)(s);
+  if (flags()->replace_str) {
+    ASAN_READ_RANGE(ctx, s, length + 1);
+  }
+  GET_STACK_TRACE_MALLOC;
+  void *new_mem = asan_malloc(length + 1, &stack);
+  REAL(memcpy)(new_mem, s, length + 1);
+  return reinterpret_cast<char*>(new_mem);
+}
+#endif
+
+INTERCEPTOR(SIZE_T, strlen, const char *s) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, strlen);
+  if (UNLIKELY(!asan_inited)) return internal_strlen(s);
+  // strlen is called from malloc_default_purgeable_zone()
+  // in __asan::ReplaceSystemAlloc() on Mac.
+  if (asan_init_is_running) {
+    return REAL(strlen)(s);
+  }
+  ENSURE_ASAN_INITED();
+  SIZE_T length = REAL(strlen)(s);
+  if (flags()->replace_str) {
+    ASAN_READ_RANGE(ctx, s, length + 1);
+  }
+  return length;
+}
+
+INTERCEPTOR(SIZE_T, wcslen, const wchar_t *s) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, wcslen);
+  SIZE_T length = REAL(wcslen)(s);
+  if (!asan_init_is_running) {
+    ENSURE_ASAN_INITED();
+    ASAN_READ_RANGE(ctx, s, (length + 1) * sizeof(wchar_t));
+  }
+  return length;
+}
+
+INTERCEPTOR(char*, strncpy, char *to, const char *from, uptr size) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, strncpy);
+  ENSURE_ASAN_INITED();
+  if (flags()->replace_str) {
+    uptr from_size = Min(size, MaybeRealStrnlen(from, size) + 1);
+    CHECK_RANGES_OVERLAP("strncpy", to, from_size, from, from_size);
+    ASAN_READ_RANGE(ctx, from, from_size);
+    ASAN_WRITE_RANGE(ctx, to, size);
+  }
+  return REAL(strncpy)(to, from, size);
+}
+
+#if ASAN_INTERCEPT_STRNLEN
+INTERCEPTOR(uptr, strnlen, const char *s, uptr maxlen) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, strnlen);
+  ENSURE_ASAN_INITED();
+  uptr length = REAL(strnlen)(s, maxlen);
+  if (flags()->replace_str) {
+    ASAN_READ_RANGE(ctx, s, Min(length + 1, maxlen));
+  }
+  return length;
+}
+#endif  // ASAN_INTERCEPT_STRNLEN
+
+static inline bool IsValidStrtolBase(int base) {
+  return (base == 0) || (2 <= base && base <= 36);
+}
+
+static inline void FixRealStrtolEndptr(const char *nptr, char **endptr) {
+  CHECK(endptr);
+  if (nptr == *endptr) {
+    // No digits were found at strtol call, we need to find out the last
+    // symbol accessed by strtoll on our own.
+    // We get this symbol by skipping leading blanks and optional +/- sign.
+    while (IsSpace(*nptr)) nptr++;
+    if (*nptr == '+' || *nptr == '-') nptr++;
+    *endptr = const_cast<char *>(nptr);
+  }
+  CHECK(*endptr >= nptr);
+}
+
+INTERCEPTOR(long, strtol, const char *nptr,  // NOLINT
+            char **endptr, int base) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, strtol);
+  ENSURE_ASAN_INITED();
+  if (!flags()->replace_str) {
+    return REAL(strtol)(nptr, endptr, base);
+  }
+  char *real_endptr;
+  long result = REAL(strtol)(nptr, &real_endptr, base);  // NOLINT
+  if (endptr != 0) {
+    *endptr = real_endptr;
+  }
+  if (IsValidStrtolBase(base)) {
+    FixRealStrtolEndptr(nptr, &real_endptr);
+    ASAN_READ_RANGE(ctx, nptr, (real_endptr - nptr) + 1);
+  }
+  return result;
+}
+
+INTERCEPTOR(int, atoi, const char *nptr) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, atoi);
+#if SANITIZER_MAC
+  if (UNLIKELY(!asan_inited)) return REAL(atoi)(nptr);
+#endif
+  ENSURE_ASAN_INITED();
+  if (!flags()->replace_str) {
+    return REAL(atoi)(nptr);
+  }
+  char *real_endptr;
+  // "man atoi" tells that behavior of atoi(nptr) is the same as
+  // strtol(nptr, 0, 10), i.e. it sets errno to ERANGE if the
+  // parsed integer can't be stored in *long* type (even if it's
+  // different from int). So, we just imitate this behavior.
+  int result = REAL(strtol)(nptr, &real_endptr, 10);
+  FixRealStrtolEndptr(nptr, &real_endptr);
+  ASAN_READ_RANGE(ctx, nptr, (real_endptr - nptr) + 1);
+  return result;
+}
+
+INTERCEPTOR(long, atol, const char *nptr) {  // NOLINT
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, atol);
+#if SANITIZER_MAC
+  if (UNLIKELY(!asan_inited)) return REAL(atol)(nptr);
+#endif
+  ENSURE_ASAN_INITED();
+  if (!flags()->replace_str) {
+    return REAL(atol)(nptr);
+  }
+  char *real_endptr;
+  long result = REAL(strtol)(nptr, &real_endptr, 10);  // NOLINT
+  FixRealStrtolEndptr(nptr, &real_endptr);
+  ASAN_READ_RANGE(ctx, nptr, (real_endptr - nptr) + 1);
+  return result;
+}
+
+#if ASAN_INTERCEPT_ATOLL_AND_STRTOLL
+INTERCEPTOR(long long, strtoll, const char *nptr,  // NOLINT
+            char **endptr, int base) {
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, strtoll);
+  ENSURE_ASAN_INITED();
+  if (!flags()->replace_str) {
+    return REAL(strtoll)(nptr, endptr, base);
+  }
+  char *real_endptr;
+  long long result = REAL(strtoll)(nptr, &real_endptr, base);  // NOLINT
+  if (endptr != 0) {
+    *endptr = real_endptr;
+  }
+  // If base has unsupported value, strtoll can exit with EINVAL
+  // without reading any characters. So do additional checks only
+  // if base is valid.
+  if (IsValidStrtolBase(base)) {
+    FixRealStrtolEndptr(nptr, &real_endptr);
+    ASAN_READ_RANGE(ctx, nptr, (real_endptr - nptr) + 1);
+  }
+  return result;
+}
+
+INTERCEPTOR(long long, atoll, const char *nptr) {  // NOLINT
+  void *ctx;
+  ASAN_INTERCEPTOR_ENTER(ctx, atoll);
+  ENSURE_ASAN_INITED();
+  if (!flags()->replace_str) {
+    return REAL(atoll)(nptr);
+  }
+  char *real_endptr;
+  long long result = REAL(strtoll)(nptr, &real_endptr, 10);  // NOLINT
+  FixRealStrtolEndptr(nptr, &real_endptr);
+  ASAN_READ_RANGE(ctx, nptr, (real_endptr - nptr) + 1);
+  return result;
+}
+#endif  // ASAN_INTERCEPT_ATOLL_AND_STRTOLL
+
+static void AtCxaAtexit(void *unused) {
+  (void)unused;
+  StopInitOrderChecking();
+}
+
+#if ASAN_INTERCEPT___CXA_ATEXIT
+INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
+            void *dso_handle) {
+#if SANITIZER_MAC
+  if (UNLIKELY(!asan_inited)) return REAL(__cxa_atexit)(func, arg, dso_handle);
+#endif
+  ENSURE_ASAN_INITED();
+  int res = REAL(__cxa_atexit)(func, arg, dso_handle);
+  REAL(__cxa_atexit)(AtCxaAtexit, 0, 0);
+  return res;
+}
+#endif  // ASAN_INTERCEPT___CXA_ATEXIT
+
+#if ASAN_INTERCEPT_FORK
+INTERCEPTOR(int, fork, void) {
+  ENSURE_ASAN_INITED();
+  if (common_flags()->coverage) CovBeforeFork();
+  int pid = REAL(fork)();
+  if (common_flags()->coverage) CovAfterFork(pid);
+  return pid;
+}
+#endif  // ASAN_INTERCEPT_FORK
+
+#if SANITIZER_WINDOWS
+INTERCEPTOR_WINAPI(DWORD, CreateThread,
+                   void* security, uptr stack_size,
+                   DWORD (__stdcall *start_routine)(void*), void* arg,
+                   DWORD thr_flags, void* tid) {
+  // Strict init-order checking is thread-hostile.
+  if (flags()->strict_init_order)
+    StopInitOrderChecking();
+  GET_STACK_TRACE_THREAD;
+  bool detached = false;  // FIXME: how can we determine it on Windows?
+  ThreadStartParam param;
+  atomic_store(&param.t, 0, memory_order_relaxed);
+  atomic_store(&param.is_registered, 0, memory_order_relaxed);
+  DWORD result = REAL(CreateThread)(security, stack_size, asan_thread_start,
+                                    &param, thr_flags, tid);
+  if (result) {
+    u32 current_tid = GetCurrentTidOrInvalid();
+    AsanThread *t =
+        AsanThread::Create(start_routine, arg, current_tid, &stack, detached);
+    atomic_store(&param.t, reinterpret_cast<uptr>(t), memory_order_release);
+    // The pthread_create interceptor waits here, so we do the same for
+    // consistency.
+    while (atomic_load(&param.is_registered, memory_order_acquire) == 0)
+      internal_sched_yield();
+  }
+  return result;
+}
+
+namespace __asan {
+void InitializeWindowsInterceptors() {
+  ASAN_INTERCEPT_FUNC(CreateThread);
+  ASAN_INTERCEPT_FUNC(RaiseException);
+  ASAN_INTERCEPT_FUNC(_except_handler3);
+  ASAN_INTERCEPT_FUNC(_except_handler4);
+}
+
+}  // namespace __asan
+#endif
+
+// ---------------------- InitializeAsanInterceptors ---------------- {{{1
+namespace __asan {
+void InitializeAsanInterceptors() {
+  static bool was_called_once;
+  CHECK(was_called_once == false);
+  was_called_once = true;
+  InitializeCommonInterceptors();
+
+  // Intercept mem* functions.
+  ASAN_INTERCEPT_FUNC(memcmp);
+  ASAN_INTERCEPT_FUNC(memmove);
+  ASAN_INTERCEPT_FUNC(memset);
+  if (PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE) {
+    ASAN_INTERCEPT_FUNC(memcpy);
+  }
+
+  // Intercept str* functions.
+  ASAN_INTERCEPT_FUNC(strcat);  // NOLINT
+  ASAN_INTERCEPT_FUNC(strchr);
+  ASAN_INTERCEPT_FUNC(strcpy);  // NOLINT
+  ASAN_INTERCEPT_FUNC(strlen);
+  ASAN_INTERCEPT_FUNC(wcslen);
+  ASAN_INTERCEPT_FUNC(strncat);
+  ASAN_INTERCEPT_FUNC(strncpy);
+#if ASAN_INTERCEPT_STRDUP
+  ASAN_INTERCEPT_FUNC(strdup);
+#endif
+#if ASAN_INTERCEPT_STRNLEN
+  ASAN_INTERCEPT_FUNC(strnlen);
+#endif
+#if ASAN_INTERCEPT_INDEX && ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX
+  ASAN_INTERCEPT_FUNC(index);
+#endif
+
+  ASAN_INTERCEPT_FUNC(atoi);
+  ASAN_INTERCEPT_FUNC(atol);
+  ASAN_INTERCEPT_FUNC(strtol);
+#if ASAN_INTERCEPT_ATOLL_AND_STRTOLL
+  ASAN_INTERCEPT_FUNC(atoll);
+  ASAN_INTERCEPT_FUNC(strtoll);
+#endif
+
+  // Intecept signal- and jump-related functions.
+  ASAN_INTERCEPT_FUNC(longjmp);
+#if ASAN_INTERCEPT_SIGNAL_AND_SIGACTION
+  ASAN_INTERCEPT_FUNC(sigaction);
+#if SANITIZER_ANDROID
+  ASAN_INTERCEPT_FUNC(bsd_signal);
+#else
+  ASAN_INTERCEPT_FUNC(signal);
+#endif
+#endif
+#if ASAN_INTERCEPT_SWAPCONTEXT
+  ASAN_INTERCEPT_FUNC(swapcontext);
+#endif
+#if ASAN_INTERCEPT__LONGJMP
+  ASAN_INTERCEPT_FUNC(_longjmp);
+#endif
+#if ASAN_INTERCEPT_SIGLONGJMP
+  ASAN_INTERCEPT_FUNC(siglongjmp);
+#endif
+
+  // Intercept exception handling functions.
+#if ASAN_INTERCEPT___CXA_THROW
+  ASAN_INTERCEPT_FUNC(__cxa_throw);
+#endif
+
+  // Intercept threading-related functions
+#if ASAN_INTERCEPT_PTHREAD_CREATE
+  ASAN_INTERCEPT_FUNC(pthread_create);
+#endif
+
+  // Intercept atexit function.
+#if ASAN_INTERCEPT___CXA_ATEXIT
+  ASAN_INTERCEPT_FUNC(__cxa_atexit);
+#endif
+
+#if ASAN_INTERCEPT_FORK
+  ASAN_INTERCEPT_FUNC(fork);
+#endif
+
+  // Some Windows-specific interceptors.
+#if SANITIZER_WINDOWS
+  InitializeWindowsInterceptors();
+#endif
+
+  VReport(1, "AddressSanitizer: libc interceptors initialized\n");
+}
+
+}  // namespace __asan