[base] Fix iOS build after AllocateSharedPages introduction

The new shared memory API should only be used on macOS, but
platform-macos.cc was also included on iOS, causing build failures. This
CL splits platform-macos.cc into platform-xnu.cc (common code for macOS
and iOS) and platform-macos.cc (the macOS specific parts)

Bug: chromium:1218005
Change-Id: Iab332865ffd8990ddd246bb9c08802909464d7e6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3468895
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79131}

BUILD.bazel

@@ -638,6 +638,7 @@ filegroup(
         "@v8//bazel/config:is_macos": [
             "src/base/debug/stack_trace_posix.cc",
             "src/base/platform/platform-macos.cc",
+            "src/base/platform/platform-xnu.cc",
         ],
         "@v8//bazel/config:is_windows": [
             "src/base/win32-headers.h",

BUILD.gn

@@ -5183,6 +5183,7 @@ v8_component("v8_libbase") {
         sources += [
           "src/base/debug/stack_trace_posix.cc",
           "src/base/platform/platform-macos.cc",
+          "src/base/platform/platform-xnu.cc",
         ]
       } else {
         sources += [
@@ -5206,10 +5207,16 @@ v8_component("v8_libbase") {
       "//third_party/fuchsia-sdk/sdk/pkg/fdio",
       "//third_party/fuchsia-sdk/sdk/pkg/zx",
     ]
-  } else if (is_mac || is_ios) {
+  } else if (is_mac) {
     sources += [
       "src/base/debug/stack_trace_posix.cc",
       "src/base/platform/platform-macos.cc",
+      "src/base/platform/platform-xnu.cc",
+    ]
+  } else if (is_ios) {
+    sources += [
+      "src/base/debug/stack_trace_posix.cc",
+      "src/base/platform/platform-xnu.cc",
     ]
   } else if (is_win) {
     # TODO(infra): Add support for cygwin.

include/v8-platform.h

@@ -522,7 +522,7 @@ static constexpr PlatformSharedMemoryHandle kInvalidSharedMemoryHandle = -1;
 // to avoid pulling in large OS header files into this header file. Instead,
 // the users of these routines are expected to include the respecitve OS
 // headers in addition to this one.
-#if V8_OS_MACOSX
+#if defined(V8_OS_MACOSX) && !defined(V8_OS_IOS)
 // Convert between a shared memory handle and a mach_port_t referencing a memory
 // entry object.
 inline PlatformSharedMemoryHandle SharedMemoryHandleFromMachMemoryEntry(
@@ -533,7 +533,7 @@ inline unsigned int MachMemoryEntryFromSharedMemoryHandle(
     PlatformSharedMemoryHandle handle) {
   return static_cast<unsigned int>(handle);
 }
-#elif V8_OS_FUCHSIA
+#elif defined(V8_OS_FUCHSIA)
 // Convert between a shared memory handle and a zx_handle_t to a VMO.
 inline PlatformSharedMemoryHandle SharedMemoryHandleFromVMO(uint32_t handle) {
   return static_cast<PlatformSharedMemoryHandle>(handle);
@@ -541,7 +541,7 @@ inline PlatformSharedMemoryHandle SharedMemoryHandleFromVMO(uint32_t handle) {
 inline uint32_t VMOFromSharedMemoryHandle(PlatformSharedMemoryHandle handle) {
   return static_cast<uint32_t>(handle);
 }
-#elif V8_OS_WIN
+#elif defined(V8_OS_WIN)
 // Convert between a shared memory handle and a Windows HANDLE to a file mapping
 // object.
 inline PlatformSharedMemoryHandle SharedMemoryHandleFromFileMapping(

src/base/platform/platform-macos.cc

@@ -2,103 +2,19 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Platform-specific code for MacOS goes here. For the POSIX-compatible
+// Platform-specific code for MacOS goes here. Code shared between iOS and
-// parts, the implementation is in platform-posix.cc.
+// macOS is in platform-xnu.cc, while the POSIX-compatible are in in
+// platform-posix.cc.
 
-#include <AvailabilityMacros.h>
-#include <dlfcn.h>
-#include <errno.h>
-#include <libkern/OSAtomic.h>
-#include <mach-o/dyld.h>
-#include <mach-o/getsect.h>
 #include <mach/mach.h>
-#include <mach/mach_init.h>
 #include <mach/mach_vm.h>
-#include <mach/semaphore.h>
-#include <mach/task.h>
 #include <mach/vm_map.h>
-#include <mach/vm_statistics.h>
-#include <pthread.h>
-#include <semaphore.h>
-#include <signal.h>
-#include <stdarg.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/mman.h>
-#include <sys/resource.h>
-#include <sys/sysctl.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <unistd.h>
 
-#include <cmath>
-
-#undef MAP_TYPE
-
-#include "src/base/macros.h"
-#include "src/base/platform/platform-posix-time.h"
-#include "src/base/platform/platform-posix.h"
 #include "src/base/platform/platform.h"
 
 namespace v8 {
 namespace base {
 
-std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() {
-  std::vector<SharedLibraryAddress> result;
-  unsigned int images_count = _dyld_image_count();
-  for (unsigned int i = 0; i < images_count; ++i) {
-    const mach_header* header = _dyld_get_image_header(i);
-    if (header == nullptr) continue;
-#if V8_HOST_ARCH_I32
-    unsigned int size;
-    char* code_ptr = getsectdatafromheader(header, SEG_TEXT, SECT_TEXT, &size);
-#else
-    uint64_t size;
-    char* code_ptr = getsectdatafromheader_64(
-        reinterpret_cast<const mach_header_64*>(header), SEG_TEXT, SECT_TEXT,
-        &size);
-#endif
-    if (code_ptr == nullptr) continue;
-    const intptr_t slide = _dyld_get_image_vmaddr_slide(i);
-    const uintptr_t start = reinterpret_cast<uintptr_t>(code_ptr) + slide;
-    result.push_back(SharedLibraryAddress(_dyld_get_image_name(i), start,
-                                          start + size, slide));
-  }
-  return result;
-}
-
-void OS::SignalCodeMovingGC() {}
-
-TimezoneCache* OS::CreateTimezoneCache() {
-  return new PosixDefaultTimezoneCache();
-}
-
-void OS::AdjustSchedulingParams() {
-#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_IA32
-  {
-    // Check availability of scheduling params.
-    uint32_t val = 0;
-    size_t valSize = sizeof(val);
-    int rc = sysctlbyname("kern.tcsm_available", &val, &valSize, NULL, 0);
-    if (rc < 0 || !val) return;
-  }
-
-  {
-    // Adjust scheduling params.
-    uint32_t val = 1;
-    int rc = sysctlbyname("kern.tcsm_enable", NULL, NULL, &val, sizeof(val));
-    DCHECK_GE(rc, 0);
-    USE(rc);
-  }
-#endif
-}
-
-std::vector<OS::MemoryRange> OS::GetFreeMemoryRangesWithin(
-    OS::Address boundary_start, OS::Address boundary_end, size_t minimum_size,
-    size_t alignment) {
-  return {};
-}
-
 namespace {
 
 vm_prot_t GetVMProtFromMemoryPermission(OS::MemoryPermission access) {
@@ -186,10 +102,5 @@ bool AddressSpaceReservation::AllocateShared(void* address, size_t size,
   return kr == KERN_SUCCESS;
 }
 
-// static
-Stack::StackSlot Stack::GetStackStart() {
-  return pthread_get_stackaddr_np(pthread_self());
-}
-
 }  // namespace base
 }  // namespace v8

src/base/platform/platform-posix.cc

@@ -435,7 +435,7 @@ bool OS::Free(void* address, size_t size) {
 }
 
 // macOS specific implementation in platform-macos.cc.
-#if !defined(V8_OS_MACOSX)
+#if !defined(V8_OS_MACOSX) || defined(V8_OS_IOS)
 // static
 void* OS::AllocateShared(void* hint, size_t size, MemoryPermission access,
                          PlatformSharedMemoryHandle handle, uint64_t offset) {
@@ -446,7 +446,7 @@ void* OS::AllocateShared(void* hint, size_t size, MemoryPermission access,
   if (result == MAP_FAILED) return nullptr;
   return result;
 }
-#endif  // !defined(V8_OS_MACOSX)
+#endif  // !defined(V8_OS_MACOSX) || defined(V8_OS_IOS)
 
 // static
 bool OS::FreeShared(void* address, size_t size) {
@@ -573,7 +573,7 @@ bool OS::FreeAddressSpaceReservation(AddressSpaceReservation reservation) {
 }
 
 // macOS specific implementation in platform-macos.cc.
-#if !defined(V8_OS_MACOSX)
+#if !defined(V8_OS_MACOSX) || defined(V8_OS_IOS)
 // static
 PlatformSharedMemoryHandle OS::CreateSharedMemoryHandleForTesting(size_t size) {
 #if V8_OS_LINUX && !V8_OS_ANDROID
@@ -594,7 +594,7 @@ void OS::DestroySharedMemoryHandle(PlatformSharedMemoryHandle handle) {
   int fd = FileDescriptorFromSharedMemoryHandle(handle);
   CHECK_EQ(0, close(fd));
 }
-#endif  // !defined(V8_OS_MACOSX)
+#endif  // !defined(V8_OS_MACOSX) || defined(V8_OS_IOS)
 
 // static
 bool OS::HasLazyCommits() {
@@ -951,7 +951,7 @@ bool AddressSpaceReservation::Free(void* address, size_t size) {
 }
 
 // macOS specific implementation in platform-macos.cc.
-#if !defined(V8_OS_MACOSX)
+#if !defined(V8_OS_MACOSX) || defined(V8_OS_IOS)
 bool AddressSpaceReservation::AllocateShared(void* address, size_t size,
                                              OS::MemoryPermission access,
                                              PlatformSharedMemoryHandle handle,
@@ -962,7 +962,7 @@ bool AddressSpaceReservation::AllocateShared(void* address, size_t size,
   return mmap(address, size, prot, MAP_SHARED | MAP_FIXED, fd, offset) !=
          MAP_FAILED;
 }
-#endif  // !defined(V8_OS_MACOSX)
+#endif  // !defined(V8_OS_MACOSX) || defined(V8_OS_IOS)
 
 bool AddressSpaceReservation::FreeShared(void* address, size_t size) {
   DCHECK(Contains(address, size));

src/base/platform/platform-xnu.cc

@@ -0,0 +1,107 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Platform-specific code shared between macOS and iOS goes here. The macOS
+// specific part is in platform-macos.cc, the POSIX-compatible parts in
+// platform-posix.cc.
+
+#include <AvailabilityMacros.h>
+#include <dlfcn.h>
+#include <errno.h>
+#include <libkern/OSAtomic.h>
+#include <mach-o/dyld.h>
+#include <mach-o/getsect.h>
+#include <mach/mach.h>
+#include <mach/mach_init.h>
+#include <mach/semaphore.h>
+#include <mach/task.h>
+#include <mach/vm_statistics.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/resource.h>
+#include <sys/sysctl.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <cmath>
+
+#undef MAP_TYPE
+
+#include "src/base/macros.h"
+#include "src/base/platform/platform-posix-time.h"
+#include "src/base/platform/platform-posix.h"
+#include "src/base/platform/platform.h"
+
+namespace v8 {
+namespace base {
+
+std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() {
+  std::vector<SharedLibraryAddress> result;
+  unsigned int images_count = _dyld_image_count();
+  for (unsigned int i = 0; i < images_count; ++i) {
+    const mach_header* header = _dyld_get_image_header(i);
+    if (header == nullptr) continue;
+#if V8_HOST_ARCH_I32
+    unsigned int size;
+    char* code_ptr = getsectdatafromheader(header, SEG_TEXT, SECT_TEXT, &size);
+#else
+    uint64_t size;
+    char* code_ptr = getsectdatafromheader_64(
+        reinterpret_cast<const mach_header_64*>(header), SEG_TEXT, SECT_TEXT,
+        &size);
+#endif
+    if (code_ptr == nullptr) continue;
+    const intptr_t slide = _dyld_get_image_vmaddr_slide(i);
+    const uintptr_t start = reinterpret_cast<uintptr_t>(code_ptr) + slide;
+    result.push_back(SharedLibraryAddress(_dyld_get_image_name(i), start,
+                                          start + size, slide));
+  }
+  return result;
+}
+
+void OS::SignalCodeMovingGC() {}
+
+TimezoneCache* OS::CreateTimezoneCache() {
+  return new PosixDefaultTimezoneCache();
+}
+
+void OS::AdjustSchedulingParams() {
+#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_IA32
+  {
+    // Check availability of scheduling params.
+    uint32_t val = 0;
+    size_t valSize = sizeof(val);
+    int rc = sysctlbyname("kern.tcsm_available", &val, &valSize, NULL, 0);
+    if (rc < 0 || !val) return;
+  }
+
+  {
+    // Adjust scheduling params.
+    uint32_t val = 1;
+    int rc = sysctlbyname("kern.tcsm_enable", NULL, NULL, &val, sizeof(val));
+    DCHECK_GE(rc, 0);
+    USE(rc);
+  }
+#endif
+}
+
+std::vector<OS::MemoryRange> OS::GetFreeMemoryRangesWithin(
+    OS::Address boundary_start, OS::Address boundary_end, size_t minimum_size,
+    size_t alignment) {
+  return {};
+}
+
+// static
+Stack::StackSlot Stack::GetStackStart() {
+  return pthread_get_stackaddr_np(pthread_self());
+}
+
+}  // namespace base
+}  // namespace v8