PR #1500: Define MAP_ANONYMOUS if not defined

Included are additional automated edits by clang-format on import.

Merge d74896699faacc4a1667603e52e72cbdc8006cf6 into 22091f4c0d6626b3ef40446ce3d4ccab19425ca3

Merging this change closes #1500

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1500 from ryandesign:MAP_ANONYMOUS d74896699faacc4a1667603e52e72cbdc8006cf6
PiperOrigin-RevId: 552922776
Change-Id: I96a0395cb5e7156d7c7a889491c5d0b4cf755819

5 files changed, 67 insertions, 73 deletions

diff --git a/absl/base/internal/low_level_alloc.cc b/absl/base/internal/low_level_alloc.cc
index 445c3458..6d2cfeac 100644
--- a/absl/base/internal/low_level_alloc.cc
+++ b/absl/base/internal/low_level_alloc.cc
@@ -47,24 +47,20 @@
 #endif
 
 #include <string.h>
+
 #include <algorithm>
 #include <atomic>
 #include <cerrno>
 #include <cstddef>
-#include <new>                   // for placement-new
+#include <new>  // for placement-new
 
 #include "absl/base/dynamic_annotations.h"
 #include "absl/base/internal/raw_logging.h"
 #include "absl/base/internal/spinlock.h"
 
-// MAP_ANONYMOUS
-#if defined(__APPLE__) || defined(__hexagon__)
-// For mmap, Linux defines both MAP_ANONYMOUS and MAP_ANON and says MAP_ANON is
-// deprecated. In Darwin, MAP_ANON is all there is.
-#if !defined MAP_ANONYMOUS
+#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
 #define MAP_ANONYMOUS MAP_ANON
-#endif  // !MAP_ANONYMOUS
-#endif  // __APPLE__
+#endif
 
 namespace absl {
 ABSL_NAMESPACE_BEGIN
@@ -126,7 +122,7 @@ static int IntLog2(size_t size, size_t base) {
 static int Random(uint32_t *state) {
   uint32_t r = *state;
   int result = 1;
-  while ((((r = r*1103515245 + 12345) >> 30) & 1) == 0) {
+  while ((((r = r * 1103515245 + 12345) >> 30) & 1) == 0) {
     result++;
   }
   *state = r;
@@ -148,7 +144,7 @@ static int LLA_SkiplistLevels(size_t size, size_t base, uint32_t *random) {
   size_t max_fit = (size - offsetof(AllocList, next)) / sizeof(AllocList *);
   int level = IntLog2(size, base) + (random != nullptr ? Random(random) : 1);
   if (static_cast<size_t>(level) > max_fit) level = static_cast<int>(max_fit);
-  if (level > kMaxLevel-1) level = kMaxLevel - 1;
+  if (level > kMaxLevel - 1) level = kMaxLevel - 1;
   ABSL_RAW_CHECK(level >= 1, "block not big enough for even one level");
   return level;
 }
@@ -157,8 +153,8 @@ static int LLA_SkiplistLevels(size_t size, size_t base, uint32_t *random) {
 // For 0 <= i < head->levels, set prev[i] to "no_greater", where no_greater
 // points to the last element at level i in the AllocList less than *e, or is
 // head if no such element exists.
-static AllocList *LLA_SkiplistSearch(AllocList *head,
-                                     AllocList *e, AllocList **prev) {
+static AllocList *LLA_SkiplistSearch(AllocList *head, AllocList *e,
+                                     AllocList **prev) {
   AllocList *p = head;
   for (int level = head->levels - 1; level >= 0; level--) {
     for (AllocList *n; (n = p->next[level]) != nullptr && n < e; p = n) {
@@ -194,7 +190,7 @@ static void LLA_SkiplistDelete(AllocList *head, AllocList *e,
     prev[i]->next[i] = e->next[i];
   }
   while (head->levels > 0 && head->next[head->levels - 1] == nullptr) {
-    head->levels--;   // reduce head->levels if level unused
+    head->levels--;  // reduce head->levels if level unused
   }
 }
 
@@ -253,9 +249,9 @@ void CreateGlobalArenas() {
 
 // Returns a global arena that does not call into hooks.  Used by NewArena()
 // when kCallMallocHook is not set.
-LowLevelAlloc::Arena* UnhookedArena() {
+LowLevelAlloc::Arena *UnhookedArena() {
   base_internal::LowLevelCallOnce(&create_globals_once, CreateGlobalArenas);
-  return reinterpret_cast<LowLevelAlloc::Arena*>(&unhooked_arena_storage);
+  return reinterpret_cast<LowLevelAlloc::Arena *>(&unhooked_arena_storage);
 }
 
 #ifndef ABSL_LOW_LEVEL_ALLOC_ASYNC_SIGNAL_SAFE_MISSING
@@ -273,7 +269,7 @@ LowLevelAlloc::Arena *UnhookedAsyncSigSafeArena() {
 // Returns the default arena, as used by LowLevelAlloc::Alloc() and friends.
 LowLevelAlloc::Arena *LowLevelAlloc::DefaultArena() {
   base_internal::LowLevelCallOnce(&create_globals_once, CreateGlobalArenas);
-  return reinterpret_cast<LowLevelAlloc::Arena*>(&default_arena_storage);
+  return reinterpret_cast<LowLevelAlloc::Arena *>(&default_arena_storage);
 }
 
 // magic numbers to identify allocated and unallocated blocks
@@ -360,8 +356,7 @@ LowLevelAlloc::Arena::Arena(uint32_t flags_value)
       min_size(2 * round_up),
       random(0) {
   freelist.header.size = 0;
-  freelist.header.magic =
-      Magic(kMagicUnallocated, &freelist.header);
+  freelist.header.magic = Magic(kMagicUnallocated, &freelist.header);
   freelist.header.arena = this;
   freelist.levels = 0;
   memset(freelist.next, 0, sizeof(freelist.next));
@@ -379,7 +374,7 @@ LowLevelAlloc::Arena *LowLevelAlloc::NewArena(uint32_t flags) {
     meta_data_arena = UnhookedArena();
   }
   Arena *result =
-    new (AllocWithArena(sizeof (*result), meta_data_arena)) Arena(flags);
+      new (AllocWithArena(sizeof(*result), meta_data_arena)) Arena(flags);
   return result;
 }
 
@@ -484,8 +479,8 @@ static void Coalesce(AllocList *a) {
     AllocList *prev[kMaxLevel];
     LLA_SkiplistDelete(&arena->freelist, n, prev);
     LLA_SkiplistDelete(&arena->freelist, a, prev);
-    a->levels = LLA_SkiplistLevels(a->header.size, arena->min_size,
-                                   &arena->random);
+    a->levels =
+        LLA_SkiplistLevels(a->header.size, arena->min_size, &arena->random);
     LLA_SkiplistInsert(&arena->freelist, a, prev);
   }
 }
@@ -493,27 +488,27 @@ static void Coalesce(AllocList *a) {
 // Adds block at location "v" to the free list
 // L >= arena->mu
 static void AddToFreelist(void *v, LowLevelAlloc::Arena *arena) {
-  AllocList *f = reinterpret_cast<AllocList *>(
-                        reinterpret_cast<char *>(v) - sizeof (f->header));
+  AllocList *f = reinterpret_cast<AllocList *>(reinterpret_cast<char *>(v) -
+                                               sizeof(f->header));
   ABSL_RAW_CHECK(f->header.magic == Magic(kMagicAllocated, &f->header),
                  "bad magic number in AddToFreelist()");
   ABSL_RAW_CHECK(f->header.arena == arena,
                  "bad arena pointer in AddToFreelist()");
-  f->levels = LLA_SkiplistLevels(f->header.size, arena->min_size,
-                                 &arena->random);
+  f->levels =
+      LLA_SkiplistLevels(f->header.size, arena->min_size, &arena->random);
   AllocList *prev[kMaxLevel];
   LLA_SkiplistInsert(&arena->freelist, f, prev);
   f->header.magic = Magic(kMagicUnallocated, &f->header);
-  Coalesce(f);                  // maybe coalesce with successor
-  Coalesce(prev[0]);            // maybe coalesce with predecessor
+  Coalesce(f);        // maybe coalesce with successor
+  Coalesce(prev[0]);  // maybe coalesce with predecessor
 }
 
 // Frees storage allocated by LowLevelAlloc::Alloc().
 // L < arena->mu
 void LowLevelAlloc::Free(void *v) {
   if (v != nullptr) {
-    AllocList *f = reinterpret_cast<AllocList *>(
-                        reinterpret_cast<char *>(v) - sizeof (f->header));
+    AllocList *f = reinterpret_cast<AllocList *>(reinterpret_cast<char *>(v) -
+                                                 sizeof(f->header));
     LowLevelAlloc::Arena *arena = f->header.arena;
     ArenaLock section(arena);
     AddToFreelist(v, arena);
@@ -528,21 +523,21 @@ void LowLevelAlloc::Free(void *v) {
 static void *DoAllocWithArena(size_t request, LowLevelAlloc::Arena *arena) {
   void *result = nullptr;
   if (request != 0) {
-    AllocList *s;       // will point to region that satisfies request
+    AllocList *s;  // will point to region that satisfies request
     ArenaLock section(arena);
     // round up with header
-    size_t req_rnd = RoundUp(CheckedAdd(request, sizeof (s->header)),
-                             arena->round_up);
-    for (;;) {      // loop until we find a suitable region
+    size_t req_rnd =
+        RoundUp(CheckedAdd(request, sizeof(s->header)), arena->round_up);
+    for (;;) {  // loop until we find a suitable region
       // find the minimum levels that a block of this size must have
       int i = LLA_SkiplistLevels(req_rnd, arena->min_size, nullptr) - 1;
-      if (i < arena->freelist.levels) {   // potential blocks exist
+      if (i < arena->freelist.levels) {        // potential blocks exist
         AllocList *before = &arena->freelist;  // predecessor of s
         while ((s = Next(i, before, arena)) != nullptr &&
                s->header.size < req_rnd) {
           before = s;
         }
-        if (s != nullptr) {       // we found a region
+        if (s != nullptr) {  // we found a region
           break;
         }
       }
@@ -596,12 +591,12 @@ static void *DoAllocWithArena(size_t request, LowLevelAlloc::Arena *arena) {
       AddToFreelist(&s->levels, arena);  // insert new region into free list
     }
     AllocList *prev[kMaxLevel];
-    LLA_SkiplistDelete(&arena->freelist, s, prev);    // remove from free list
+    LLA_SkiplistDelete(&arena->freelist, s, prev);  // remove from free list
     // s points to the first free region that's big enough
     if (CheckedAdd(req_rnd, arena->min_size) <= s->header.size) {
       // big enough to split
-      AllocList *n = reinterpret_cast<AllocList *>
-                        (req_rnd + reinterpret_cast<char *>(s));
+      AllocList *n =
+          reinterpret_cast<AllocList *>(req_rnd + reinterpret_cast<char *>(s));
       n->header.size = s->header.size - req_rnd;
       n->header.magic = Magic(kMagicAllocated, &n->header);
       n->header.arena = arena;
diff --git a/absl/debugging/failure_signal_handler.cc b/absl/debugging/failure_signal_handler.cc
index fd6a4927..992c89c3 100644
--- a/absl/debugging/failure_signal_handler.cc
+++ b/absl/debugging/failure_signal_handler.cc
@@ -31,6 +31,9 @@
 
 #ifdef ABSL_HAVE_MMAP
 #include <sys/mman.h>
+#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
 #endif
 
 #ifdef __linux__
@@ -81,10 +84,10 @@ struct FailureSignalData {
   struct sigaction previous_action;
   // StructSigaction is used to silence -Wmissing-field-initializers.
   using StructSigaction = struct sigaction;
-  #define FSD_PREVIOUS_INIT FailureSignalData::StructSigaction()
+#define FSD_PREVIOUS_INIT FailureSignalData::StructSigaction()
 #else
   void (*previous_handler)(int);
-  #define FSD_PREVIOUS_INIT SIG_DFL
+#define FSD_PREVIOUS_INIT SIG_DFL
 #endif
 };
 
@@ -136,7 +139,7 @@ const char* FailureSignalToString(int signo) {
 #ifdef ABSL_HAVE_SIGALTSTACK
 
 static bool SetupAlternateStackOnce() {
-#if defined(__wasm__) || defined (__asjms__)
+#if defined(__wasm__) || defined(__asjms__)
   const size_t page_mask = getpagesize() - 1;
 #else
   const size_t page_mask = static_cast<size_t>(sysconf(_SC_PAGESIZE)) - 1;
@@ -158,9 +161,6 @@ static bool SetupAlternateStackOnce() {
 #ifndef MAP_STACK
 #define MAP_STACK 0
 #endif
-#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
-#define MAP_ANONYMOUS MAP_ANON
-#endif
   sigstk.ss_sp = mmap(nullptr, sigstk.ss_size, PROT_READ | PROT_WRITE,
                       MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0);
   if (sigstk.ss_sp == MAP_FAILED) {
@@ -248,7 +248,7 @@ static void WriteSignalMessage(int signo, int cpu,
   if (signal_string != nullptr && signal_string[0] != '\0') {
     snprintf(buf, sizeof(buf), "*** %s received at time=%ld%s ***\n",
              signal_string,
-             static_cast<long>(time(nullptr)),   // NOLINT(runtime/int)
+             static_cast<long>(time(nullptr)),  // NOLINT(runtime/int)
              on_cpu);
   } else {
     snprintf(buf, sizeof(buf), "*** Signal %d received at time=%ld%s ***\n",
@@ -311,7 +311,8 @@ static void PortableSleepForSeconds(int seconds) {
   struct timespec sleep_time;
   sleep_time.tv_sec = seconds;
   sleep_time.tv_nsec = 0;
-  while (nanosleep(&sleep_time, &sleep_time) != 0 && errno == EINTR) {}
+  while (nanosleep(&sleep_time, &sleep_time) != 0 && errno == EINTR) {
+  }
 #endif
 }
 
@@ -321,9 +322,7 @@ static void PortableSleepForSeconds(int seconds) {
 // set amount of time. If AbslFailureSignalHandler() hangs for more than
 // the alarm timeout, ImmediateAbortSignalHandler() will abort the
 // program.
-static void ImmediateAbortSignalHandler(int) {
-  RaiseToDefaultHandler(SIGABRT);
-}
+static void ImmediateAbortSignalHandler(int) { RaiseToDefaultHandler(SIGABRT); }
 #endif
 
 // absl::base_internal::GetTID() returns pid_t on most platforms, but
diff --git a/absl/debugging/internal/examine_stack.cc b/absl/debugging/internal/examine_stack.cc
index 57863228..3dd6ba1a 100644
--- a/absl/debugging/internal/examine_stack.cc
+++ b/absl/debugging/internal/examine_stack.cc
@@ -24,6 +24,9 @@
 
 #ifdef ABSL_HAVE_MMAP
 #include <sys/mman.h>
+#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
 #endif
 
 #if defined(__linux__) || defined(__APPLE__)
diff --git a/absl/debugging/internal/stack_consumption.cc b/absl/debugging/internal/stack_consumption.cc
index 6d974992..3f40beac 100644
--- a/absl/debugging/internal/stack_consumption.cc
+++ b/absl/debugging/internal/stack_consumption.cc
@@ -18,14 +18,17 @@
 #ifdef ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION
 
 #include <signal.h>
+#include <string.h>
 #include <sys/mman.h>
 #include <unistd.h>
 
-#include <string.h>
-
 #include "absl/base/attributes.h"
 #include "absl/base/internal/raw_logging.h"
 
+#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace debugging_internal {
diff --git a/absl/debugging/symbolize_test.cc b/absl/debugging/symbolize_test.cc
index 922fe36f..d0feab2f 100644
--- a/absl/debugging/symbolize_test.cc
+++ b/absl/debugging/symbolize_test.cc
@@ -40,6 +40,10 @@
 #include "absl/memory/memory.h"
 #include "absl/strings/string_view.h"
 
+#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
 using testing::Contains;
 
 #ifdef _WIN32
@@ -86,21 +90,13 @@ int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.unlikely) unlikely_func() {
   return 0;
 }
 
-int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.hot) hot_func() {
-  return 0;
-}
+int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.hot) hot_func() { return 0; }
 
-int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.startup) startup_func() {
-  return 0;
-}
+int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.startup) startup_func() { return 0; }
 
-int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.exit) exit_func() {
-  return 0;
-}
+int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.exit) exit_func() { return 0; }
 
-int /*ABSL_ATTRIBUTE_SECTION_VARIABLE(.text)*/ regular_func() {
-  return 0;
-}
+int /*ABSL_ATTRIBUTE_SECTION_VARIABLE(.text)*/ regular_func() { return 0; }
 
 // Thread-local data may confuse the symbolizer, ensure that it does not.
 // Variable sizes and order are important.
@@ -121,7 +117,7 @@ static volatile bool volatile_bool = false;
 // Force the binary to be large enough that a THP .text remap will succeed.
 static constexpr size_t kHpageSize = 1 << 21;
 const char kHpageTextPadding[kHpageSize * 4] ABSL_ATTRIBUTE_SECTION_VARIABLE(
-    .text) = "";
+        .text) = "";
 
 #else
 static void *GetPCFromFnPtr(void *ptr) {
@@ -313,10 +309,8 @@ TEST(Symbolize, SymbolizeWithDemanglingStackConsumption) {
 const size_t kPageSize = 64 << 10;
 // We place a read-only symbols into the .text section and verify that we can
 // symbolize them and other symbols after remapping them.
-const char kPadding0[kPageSize * 4] ABSL_ATTRIBUTE_SECTION_VARIABLE(.text) =
-    "";
-const char kPadding1[kPageSize * 4] ABSL_ATTRIBUTE_SECTION_VARIABLE(.text) =
-    "";
+const char kPadding0[kPageSize * 4] ABSL_ATTRIBUTE_SECTION_VARIABLE(.text) = "";
+const char kPadding1[kPageSize * 4] ABSL_ATTRIBUTE_SECTION_VARIABLE(.text) = "";
 
 static int FilterElfHeader(struct dl_phdr_info *info, size_t size, void *data) {
   for (int i = 0; i < info->dlpi_phnum; i++) {
@@ -474,9 +468,9 @@ extern "C" {
 inline void *ABSL_ATTRIBUTE_ALWAYS_INLINE inline_func() {
   void *pc = nullptr;
 #if defined(__i386__)
-  __asm__ __volatile__("call 1f;\n 1: pop %[PC]" : [ PC ] "=r"(pc));
+  __asm__ __volatile__("call 1f;\n 1: pop %[PC]" : [PC] "=r"(pc));
 #elif defined(__x86_64__)
-  __asm__ __volatile__("leaq 0(%%rip),%[PC];\n" : [ PC ] "=r"(pc));
+  __asm__ __volatile__("leaq 0(%%rip),%[PC];\n" : [PC] "=r"(pc));
 #endif
   return pc;
 }
@@ -484,9 +478,9 @@ inline void *ABSL_ATTRIBUTE_ALWAYS_INLINE inline_func() {
 void *ABSL_ATTRIBUTE_NOINLINE non_inline_func() {
   void *pc = nullptr;
 #if defined(__i386__)
-  __asm__ __volatile__("call 1f;\n 1: pop %[PC]" : [ PC ] "=r"(pc));
+  __asm__ __volatile__("call 1f;\n 1: pop %[PC]" : [PC] "=r"(pc));
 #elif defined(__x86_64__)
-  __asm__ __volatile__("leaq 0(%%rip),%[PC];\n" : [ PC ] "=r"(pc));
+  __asm__ __volatile__("leaq 0(%%rip),%[PC];\n" : [PC] "=r"(pc));
 #endif
   return pc;
 }
@@ -601,7 +595,7 @@ TEST(Symbolize, SymbolizeWithDemangling) {
 }
 
 #endif  // !defined(ABSL_CONSUME_DLL)
-#else  // Symbolizer unimplemented
+#else   // Symbolizer unimplemented
 TEST(Symbolize, Unimplemented) {
   char buf[64];
   EXPECT_FALSE(absl::Symbolize((void *)(&nonstatic_func), buf, sizeof(buf)));