Reverts refactoring of CPU feature detection for

runtime/vm/cpuinfo_linux.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_LINUX)
-
-#include "vm/cpuinfo.h"
-
-#include <ctype.h>  // NOLINT
-#include <string.h>  // NOLINT
-
-#include "platform/assert.h"
-
-namespace dart {
-
-char* CpuInfo::data_ = NULL;
-intptr_t CpuInfo::datalen_ = 0;
-
-void CpuInfo::InitOnce() {
-  InitializeFields();
-
-  // Get the size of the cpuinfo file by reading it until the end. This is
-  // required because files under /proc do not always return a valid size
-  // when using fseek(0, SEEK_END) + ftell(). Nor can they be mmap()-ed.
-  static const char PATHNAME[] = "/proc/cpuinfo";
-  FILE* fp = fopen(PATHNAME, "r");
-  if (fp != NULL) {
-    for (;;) {
-      char buffer[256];
-      size_t n = fread(buffer, 1, sizeof(buffer), fp);
-      if (n == 0) {
-        break;
-      }
-      datalen_ += n;
-    }
-    fclose(fp);
-  }
-
-  // Read the contents of the cpuinfo file.
-  data_ = new char[datalen_ + 1];
-  fp = fopen(PATHNAME, "r");
-  if (fp != NULL) {
-    for (intptr_t offset = 0; offset < datalen_; ) {
-      size_t n = fread(data_ + offset, 1, datalen_ - offset, fp);
-      if (n == 0) {
-        break;
-      }
-      offset += n;
-    }
-    fclose(fp);
-  }
-
-  // Zero-terminate the data.
-  data_[datalen_] = '\0';
-}
-
-
-static char* FieldStart(char* data, const char* field) {
-  // Look for first field occurrence, and ensure it starts the line.
-  size_t fieldlen = strlen(field);
-  char* p = data;
-  for (;;) {
-    p = strstr(p, field);
-    if (p == NULL) {
-      return NULL;
-    }
-    if (p == data || p[-1] == '\n') {
-      break;
-    }
-    p += fieldlen;
-  }
-
-  // Skip to the first colon followed by a space.
-  p = strchr(p + fieldlen, ':');
-  if (p == NULL || !isspace(p[1])) {
-    return NULL;
-  }
-  p += 2;
-
-  return p;
-}
-
-
-bool CpuInfo::FieldContains(const char* field, const char* search_string) {
-  ASSERT(data_ != NULL);
-  ASSERT(search_string != NULL);
-
-  char *p = FieldStart(data_, field);
-  if (p == NULL) {
-    return false;
-  }
-
-  // Find the end of the line.
-  char* q = strchr(p, '\n');
-  if (q == NULL) {
-    q = data_ + datalen_;
-  }
-
-  char saved_end = *q;
-  *q = '\0';
-  bool ret = (strcasestr(p, search_string) != NULL);
-  *q = saved_end;
-
-  return ret;
-}
-
-
-// Extract the content of a the first occurrence of a given field in
-// the content of the cpuinfo file and return it as a heap-allocated
-// string that must be freed by the caller using delete[].
-// Return NULL if not found.
-char* CpuInfo::ExtractField(const char* field) {
-  ASSERT(field != NULL);
-  ASSERT(data_ != NULL);
-
-  char* p = FieldStart(data_, field);
-  if (p == NULL) {
-    return NULL;
-  }
-
-  // Find the end of the line.
-  char* q = strchr(p, '\n');
-  if (q == NULL) {
-    q = data_ + datalen_;
-  }
-
-  intptr_t len = q - p;
-  char *result = new char[len + 1];  // plus one for null-terminator.
-  // Copy the line into result, leaving enough room for a null-terminator.
-  char saved_end = *q;
-  *q = '\0';
-  strncpy(result, p, len);
-  result[len] = '\0';
-  *q = saved_end;
-
-  return result;
-}
-
-
-bool CpuInfo::HasField(const char* field) {
-  ASSERT(field != NULL);
-  ASSERT(data_ != NULL);
-  return (FieldStart(data_, field) != NULL);
-}
-
-
-const char* CpuInfo::fields_[kCpuInfoMax] = {0};
-void CpuInfo::InitializeFields() {
-#if defined(HOST_ARCH_IA32) || defined(HOST_ARCH_X64)
-  fields_[kCpuInfoProcessor] = "vendor_id";
-  fields_[kCpuInfoModel] = "model name";
-  fields_[kCpuInfoFeatures] = "flags";
-#elif defined(HOST_ARCH_ARM)
-  fields_[kCpuInfoProcessor] = "Processor";
-  fields_[kCpuInfoModel] = "Hardware";
-  fields_[kCpuInfoFeatures] = "Features";
-#elif defined(HOST_ARCH_MIPS)
-  fields_[kCpuInfoProcessor] = "system type";
-  fields_[kCpuInfoModel] = "cpu model";
-  fields_[kCpuInfoFeatures] = "ASEs implemented";
-#else
-#error Unrecognized target architecture
-#endif
-}
-
-}  // namespace dart
-
-#endif  // defined(TARGET_OS_LINUX)