Refactors CPU feature detection.

runtime/vm/cpuinfo.h

+// 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.
+
+#ifndef VM_CPUINFO_H_
+#define VM_CPUINFO_H_
+
+#include "vm/allocation.h"
+
+namespace dart {
+
+class CpuInfo : public AllStatic {
+ public:
+  // If necessary, allocates a buffer [data_] and reads cpuinfo into
+  // that buffer.
+  static void Read();

[Cutch, 2014/01/02 19:39:19]

Rename to InitOnce ?

+
+  // Returns true if the cpuinfo field [field] contains the
+  // string [search_string].
+  static bool FieldContains(const char* field, const char* search_string);
+
+  // Returns true if the cpuinfo field [field] exists and is non-empty.
+  static bool HasField(const char* field);
+
+  // Reads the cpuinfo field [field] into the buffer [dest] and returns the
+  // length of the field.
+  // If [dest] is NULL, ExtractField just returns the length.
+  static intptr_t ExtractField(
+      const char* field, char* dest, const intptr_t dest_len);
+
+  // Returns the length of the cpuinfo field [field].
+  static intptr_t FieldLength(const char* field) {
+    return ExtractField(field, NULL, 0);
+  }
+
+  // Reads the cpuinfo field describing the CPU model into the buffer [dest].
+  static intptr_t GetCpuModel(char* dest, const intptr_t dest_len);
+
+ private:
+  // On Linux and Android data_ holds /proc/cpuinfo after Read().
+  static char* data_;
+  // On Linux and Android, the length of /proc/cpuinfo.
+  static intptr_t datalen_;
+};
+
+}  // namespace dart
+
+#endif  // VM_CPUINFO_H_