Parsing /proc/cpuinfo for model on Android and Aura

base/cpu.cc

Index: base/cpu.cc
diff --git a/base/cpu.cc b/base/cpu.cc
index 66207a1e0b8b0539b99a72b85435936f847803bb..5c23dfe070d0fb5f8182e41922078026ac523d16 100644
--- a/base/cpu.cc
+++ b/base/cpu.cc
@@ -9,6 +9,7 @@
 #include <algorithm>
 
 #include "base/basictypes.h"
+#include "base/file_util.h"
 #include "build/build_config.h"
 
 #if defined(ARCH_CPU_X86_FAMILY)
@@ -158,12 +159,22 @@ void CPU::Initialize() {
     has_non_stop_time_stamp_counter_ = (cpu_info[3] & (1 << 8)) != 0;
   }
 #elif defined(ARCH_CPU_ARM_FAMILY)
-  // TODO(piman): Expand this. ARM has a CPUID register, but it's not available
-  // in user mode. /proc/cpuinfo has some information, but it's non standard,
-  // platform-specific, and not accessible from the sandbox.
-  // For some purposes, this first approximation is enough.
-  // crbug.com/313454
-  cpu_brand_.assign("ARM");
+#if defined(USE_AURA) || defined(OS_ANDROID)
+  const char kProcessorPrefix[] = "Processor";
+  std::string contents;
+  ReadFileToString(FilePath("/proc/cpuinfo"), &contents);

[Mark Mentovai, 2014/03/06 14:41:55]

How is this file formatted on ARM?

It’s probably too long to stick in a comment, but it’s helpful during review to
know what the entire file, and specifically the Processor line, actually looks
like.

[rptr, 2014/03/08 06:26:59]

This is how /proc/cpuinfo looks in Samsung Galaxy S2.

Processor       : ARMv7 Processor rev 1 (v7l)
processor       : 0
BogoMIPS        : 1592.52

processor       : 1
BogoMIPS        : 2388.78

Features        : swp half thumb fastmult vfp edsp neon vfpv3 tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x2
CPU part        : 0xc09
CPU revision    : 1

Hardware        : SMDK4210
Revision        : 000e
Serial          : *****

Same format is seen in all other android devices which i checked(Nexus S, Note
etc).

+  DCHECK(!contents.empty());
+  if (!contents.empty()) {
+    std::istringstream iss(contents);
+    std::string line;
+    while (std::getline(iss, line)) {
+      if (line.compare(0, strlen(kProcessorPrefix), kProcessorPrefix) == 0) {
+        size_t pos = line.find(": ");

[Mark Mentovai, 2014/03/07 15:19:18]

What if ": " was not found?

+        cpu_brand_.assign(line.substr(pos + 2));

[vivekg, 2014/03/07 11:59:52]

You probably need to break here to avoid processing further.

+      }
+    }
+  }
+#endif
 #endif
 }