Updates refactoring of CPU feature detection

runtime/vm/cpuinfo_macos.cc

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "vm/globals.h"
+#if defined(TARGET_OS_MACOS)
+
+#include "vm/cpuinfo.h"
+
+#include <errno.h>  // NOLINT
+#include <sys/types.h>  // NOLINT
+#include <sys/sysctl.h>  // NOLINT
+
+#include "platform/assert.h"
+
+namespace dart {
+
+CpuInfoMethod CpuInfo::method_ = kCpuInfoDefault;
+const char* CpuInfo::fields_[kCpuInfoMax] = {0};
+
+void CpuInfo::InitOnce(CpuInfoMethod method) {
+  // On MacOS, only the system call method is supported.
+  ASSERT((method == kCpuInfoDefault) || (method == kCpuInfoSystem));
+  method_ = kCpuInfoSystem;
+
+  fields_[kCpuInfoProcessor] = "machdep.cpu.vendor";
+  fields_[kCpuInfoModel] = "machdep.cpu.brand_string";
+  fields_[kCpuInfoHardware] = "machdep.cpu.brand_string";
+  fields_[kCpuInfoFeatures] = "machdep.cpu.features";
+}
+
+
+bool CpuInfo::FieldContainsByString(const char* field,
+                                    const char* search_string) {
+  ASSERT(search_string != NULL);
+  char dest[1024];
+  size_t dest_len = 1024;
+
+  ASSERT(HasField(field));
+  if (sysctlbyname(field, dest, &dest_len, NULL, 0) != 0) {
+    UNREACHABLE();
+    return false;
+  }
+
+  return (strcasestr(dest, search_string) != NULL);
+}
+
+
+bool CpuInfo::FieldContains(CpuInfoIndices idx, const char* search_string) {
+  return FieldContainsByString(FieldName(idx), search_string);
+}
+
+
+const char* CpuInfo::ExtractFieldByString(const char* field) {
+  ASSERT(field != NULL);
+  size_t result_len;
+
+  ASSERT(HasField(field));
+  if (sysctlbyname(field, NULL, &result_len, NULL, 0) != 0) {
+    UNREACHABLE();
+    return 0;
+  }
+
+  char* result = new char[result_len];
+  if (sysctlbyname(field, result, &result_len, NULL, 0) != 0) {
+    UNREACHABLE();
+    return 0;
+  }
+
+  return result;
+}
+
+
+const char* CpuInfo::ExtractField(CpuInfoIndices idx) {
+  return ExtractFieldByString(FieldName(idx));
+}
+
+
+bool CpuInfo::HasField(const char* field) {
+  ASSERT(field != NULL);
+  int ret = sysctlbyname(field, NULL, NULL, NULL, 0);
+  return (ret != ENOENT);
+}
+
+}  // namespace dart
+
+#endif  // defined(TARGET_OS_MACOS)