Report all system temperatures, not just CPU

chrome/browser/chromeos/policy/device_status_collector.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/policy/device_status_collector.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 138 matching lines @@
       if (line.compare(0, 4, "cpu ") == 0)
         return line;
     }
     // First line should always start with "cpu ".
     NOTREACHED() << "Could not parse /proc/stat contents: " << contents;
   }
   LOG(WARNING) << "Unable to read CPU statistics from " << kProcStat;
   return std::string();
 }
 
 // Reads the CPU temperature info from

[pastarmovj, 2016/09/23 09:28:11]

Please update this comment to reflect the new logic.

 // /sys/class/hwmon/hwmon*/device/temp*_input and
 // /sys/class/hwmon/hwmon*/device/temp*_label files.
 //
 // temp*_input contains CPU temperature in millidegree Celsius
 // temp*_label contains appropriate temperature channel label.
 std::vector<em::CPUTempInfo> ReadCPUTempInfo() {
   std::vector<em::CPUTempInfo> contents;
   // Get directories /sys/class/hwmon/hwmon*
   base::FileEnumerator hwmon_enumerator(base::FilePath(kHwmonDir), false,
                                         base::FileEnumerator::DIRECTORIES,
                                         kHwmonDirectoryPattern);
 
   for (base::FilePath hwmon_path = hwmon_enumerator.Next(); !hwmon_path.empty();
        hwmon_path = hwmon_enumerator.Next()) {
-    // Get files /sys/class/hwmon/hwmon*/device/temp*_input
-    const base::FilePath hwmon_device_dir = hwmon_path.Append(kDeviceDir);
-    base::FileEnumerator enumerator(hwmon_device_dir, false,
-                                    base::FileEnumerator::FILES,
-                                    kCPUTempFilePattern);
+    // Get temp*_input files in hwmon*/ and hwmon*/device/
+    if (base::PathExists(hwmon_path.Append(kDeviceDir))) {
+      hwmon_path = hwmon_path.Append(kDeviceDir);
+    }
+    base::FileEnumerator enumerator(
+        hwmon_path, false, base::FileEnumerator::FILES, kCPUTempFilePattern);
     for (base::FilePath temperature_path = enumerator.Next();
          !temperature_path.empty(); temperature_path = enumerator.Next()) {
       // Get appropriate temp*_label file.
       std::string label_path = temperature_path.MaybeAsASCII();
       if (label_path.empty()) {
         LOG(WARNING) << "Unable to parse a path to temp*_input file as ASCII";
         continue;
       }
       base::ReplaceSubstringsAfterOffset(&label_path, 0, "input", "label");
+      base::FilePath name_path = hwmon_path.Append("name");
 
-      // Read label.
+      // Get the label describing this temperature. Use temp*_label
+      // if present, fall back on name file or blank.
       std::string label;
-      if (!base::PathExists(base::FilePath(label_path)) ||
-          !base::ReadFileToString(base::FilePath(label_path), &label)) {
+      if (base::PathExists(base::FilePath(label_path))) {
+        base::ReadFileToString(base::FilePath(label_path), &label);

[Andrew T Wilson (Slow), 2016/09/06 18:10:45]

I'm concerned that if ReadFileToString() returns an error, behavior is undefined
(since |label| can be modified here). Is ReadFileToString() guaranteed to leave
|label| empty if there's an error reading the file?

[Jay Lee, 2016/09/14 15:24:54]

As far as I can see at:

https://chromium.googlesource.com/chromium/src/+/master/base/files/file_util....

ReadFileToString() and ReadFileToStringWithMaxSize() would only return empty,
partial file content or full file content.

I'm happy to rewrite this block if you think it's necessary but I'm uncertain
what it would need to look like.

+      } else if (base::PathExists(base::FilePath(name_path))) {
+        base::ReadFileToString(name_path, &label);
+      } else {
         label = std::string();
       }
 
       // Read temperature in millidegree Celsius.
       std::string temperature_string;
       int32_t temperature = 0;
       if (base::ReadFileToString(temperature_path, &temperature_string) &&
           sscanf(temperature_string.c_str(), "%d", &temperature) == 1) {
         // CPU temp in millidegree Celsius to Celsius
         temperature /= 1000;
@@ skipping 851 matching lines @@
   ScheduleGeolocationUpdateRequest();
 }
 
 void DeviceStatusCollector::ReceiveVolumeInfo(
     const std::vector<em::VolumeInfo>& info) {
   if (report_hardware_status_)
     volume_info_ = info;
 }
 
 }  // namespace policy