Pepper: Refactor cpu feature attributes.

We'll want to break up ppb_nacl_private_impl.cc instead of lumping things into
one large file. This change makes the method for getting CPU feature attributes
easier to reuse, and renames the sandbox_arch.{cc,h} files in the process.

This is split off from a larger change to remove FileDownloader in the trusted
plugin.

BUG=370556
R=bbudge@chromium.org

Review URL: https://codereview.chromium.org/399983002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283861 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 102 insertions, 105 deletions

diff --git a/components/nacl/renderer/nexe_load_manager.cc b/components/nacl/renderer/nexe_load_manager.cc
index 713c7f2..adbc4c9 100644
--- a/components/nacl/renderer/nexe_load_manager.cc
+++ b/components/nacl/renderer/nexe_load_manager.cc
@@ -13,9 +13,9 @@
 #include "components/nacl/common/nacl_types.h"
 #include "components/nacl/renderer/histogram.h"
 #include "components/nacl/renderer/manifest_service_channel.h"
+#include "components/nacl/renderer/platform_info.h"
 #include "components/nacl/renderer/pnacl_translation_resource_host.h"
 #include "components/nacl/renderer/progress_event.h"
-#include "components/nacl/renderer/sandbox_arch.h"
 #include "components/nacl/renderer/trusted_plugin_channel.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
diff --git a/components/nacl/renderer/platform_info.cc b/components/nacl/renderer/platform_info.cc
new file mode 100644
index 0000000..712526c
--- /dev/null
+++ b/components/nacl/renderer/platform_info.cc
@@ -0,0 +1,81 @@
+// Copyright 2014 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 "base/cpu.h"
+#include "base/logging.h"
+#include "base/strings/string_util.h"
+#if defined(OS_WIN)
+#include "base/win/windows_version.h"
+#endif
+
+namespace nacl {
+
+const char* GetSandboxArch() {
+#if defined(ARCH_CPU_ARM_FAMILY)
+  return "arm";
+#elif defined(ARCH_CPU_MIPS_FAMILY)
+  return "mips32";
+#elif defined(ARCH_CPU_X86_FAMILY)
+
+#if defined(OS_WIN)
+  // We have to check the host architecture on Windows.
+  // See sandbox_isa.h for an explanation why.
+  if (base::win::OSInfo::GetInstance()->architecture() ==
+      base::win::OSInfo::X64_ARCHITECTURE)
+    return "x86-64";
+  else
+    return "x86-32";
+#elif ARCH_CPU_64_BITS
+  return "x86-64";
+#else
+  return "x86-32";
+#endif  // defined(OS_WIN)
+
+#else
+#error Architecture not supported.
+#endif
+}
+
+std::string GetCpuFeatures() {
+  // PNaCl's translator from pexe to nexe can be told exactly what
+  // capabilities the user's machine has because the pexe to nexe
+  // translation is specific to the machine, and CPU information goes
+  // into the translation cache. This allows the translator to generate
+  // faster code.
+  //
+  // Care must be taken to avoid instructions which aren't supported by
+  // the NaCl sandbox. Ideally the translator would do this, but there's
+  // no point in not doing the whitelist here.
+  //
+  // TODO(jfb) Some features are missing, either because the NaCl
+  //           sandbox doesn't support them, because base::CPU doesn't
+  //           detect them, or because they don't help vector shuffles
+  //           (and we omit them because it simplifies testing). Add the
+  //           other features.
+  //
+  // TODO(jfb) The following is x86-specific. The base::CPU class
+  //           doesn't handle other architectures very well, and we
+  //           should at least detect the presence of ARM's integer
+  //           divide.
+  std::vector<std::string> features;
+  base::CPU cpu;
+
+  // On x86, SSE features are ordered: the most recent one implies the
+  // others. Care is taken here to only specify the latest SSE version,
+  // whereas non-SSE features don't follow this model: POPCNT is
+  // effectively always implied by SSE4.2 but has to be specified
+  // separately.
+  //
+  // TODO: AVX2, AVX, SSE 4.2.
+  if (cpu.has_sse41()) features.push_back("+sse4.1");
+  // TODO: SSE 4A, SSE 4.
+  else if (cpu.has_ssse3()) features.push_back("+ssse3");
+  // TODO: SSE 3
+  else if (cpu.has_sse2()) features.push_back("+sse2");
+
+  // TODO: AES, POPCNT, LZCNT, ...
+  return JoinString(features, ',');
+}
+
+}  // namespace nacl
diff --git a/components/nacl/renderer/platform_info.h b/components/nacl/renderer/platform_info.h
new file mode 100644
index 0000000..719b060
--- /dev/null
+++ b/components/nacl/renderer/platform_info.h
@@ -0,0 +1,18 @@
+// Copyright 2014 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.
+
+#ifndef COMPONENTS_NACL_RENDERER_PLATFORM_INFO_H
+#define COMPONENTS_NACL_RENDERER_PLATFORM_INFO_H
+
+namespace nacl {
+// Returns the kind of SFI sandbox implemented by NaCl on this
+// platform.  See the implementation in platform_info.cc for possible
+// values.
+const char* GetSandboxArch();
+
+// Returns the features for the system's processor. Used for PNaCl translation.
+std::string GetCpuFeatures();
+}  // namespace nacl
+
+#endif  // COMPONENTS_NACL_RENDERER_PLATFORM_INFO_H
diff --git a/components/nacl/renderer/ppb_nacl_private_impl.cc b/components/nacl/renderer/ppb_nacl_private_impl.cc
index 79cbf9c..aa66f08 100644
--- a/components/nacl/renderer/ppb_nacl_private_impl.cc
+++ b/components/nacl/renderer/ppb_nacl_private_impl.cc
@@ -28,9 +28,9 @@
 #include "components/nacl/renderer/manifest_downloader.h"
 #include "components/nacl/renderer/manifest_service_channel.h"
 #include "components/nacl/renderer/nexe_load_manager.h"
+#include "components/nacl/renderer/platform_info.h"
 #include "components/nacl/renderer/pnacl_translation_resource_host.h"
 #include "components/nacl/renderer/progress_event.h"
-#include "components/nacl/renderer/sandbox_arch.h"
 #include "components/nacl/renderer/trusted_plugin_channel.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
@@ -1219,54 +1219,8 @@ PP_Bool GetPNaClResourceInfo(PP_Instance instance,
   return PP_TRUE;
 }
 
-// Helper to std::accumulate that creates a comma-separated list from the input.
-std::string CommaAccumulator(const std::string &lhs, const std::string &rhs) {
-  if (lhs.empty())
-    return rhs;
-  return lhs + "," + rhs;
-}
-
 PP_Var GetCpuFeatureAttrs() {
-  // PNaCl's translator from pexe to nexe can be told exactly what
-  // capabilities the user's machine has because the pexe to nexe
-  // translation is specific to the machine, and CPU information goes
-  // into the translation cache. This allows the translator to generate
-  // faster code.
-  //
-  // Care must be taken to avoid instructions which aren't supported by
-  // the NaCl sandbox. Ideally the translator would do this, but there's
-  // no point in not doing the whitelist here.
-  //
-  // TODO(jfb) Some features are missing, either because the NaCl
-  //           sandbox doesn't support them, because base::CPU doesn't
-  //           detect them, or because they don't help vector shuffles
-  //           (and we omit them because it simplifies testing). Add the
-  //           other features.
-  //
-  // TODO(jfb) The following is x86-specific. The base::CPU class
-  //           doesn't handle other architectures very well, and we
-  //           should at least detect the presence of ARM's integer
-  //           divide.
-  std::vector<std::string> attrs;
-  base::CPU cpu;
-
-  // On x86, SSE features are ordered: the most recent one implies the
-  // others. Care is taken here to only specify the latest SSE version,
-  // whereas non-SSE features don't follow this model: POPCNT is
-  // effectively always implied by SSE4.2 but has to be specified
-  // separately.
-  //
-  // TODO: AVX2, AVX, SSE 4.2.
-  if (cpu.has_sse41()) attrs.push_back("+sse4.1");
-  // TODO: SSE 4A, SSE 4.
-  else if (cpu.has_ssse3()) attrs.push_back("+ssse3");
-  // TODO: SSE 3
-  else if (cpu.has_sse2()) attrs.push_back("+sse2");
-
-  // TODO: AES, POPCNT, LZCNT, ...
-
-  return ppapi::StringVar::StringToPPVar(std::accumulate(
-      attrs.begin(), attrs.end(), std::string(), CommaAccumulator));
+  return ppapi::StringVar::StringToPPVar(GetCpuFeatures());
 }
 
 void PostMessageToJavaScriptMainThread(PP_Instance instance,
diff --git a/components/nacl/renderer/sandbox_arch.cc b/components/nacl/renderer/sandbox_arch.cc
deleted file mode 100644
index 944bbc2..0000000
--- a/components/nacl/renderer/sandbox_arch.cc
+++ /dev/null
@@ -1,38 +0,0 @@
-// Copyright 2014 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 "base/logging.h"
-#if defined(OS_WIN)
-#include "base/win/windows_version.h"
-#endif
-
-namespace nacl {
-
-const char* GetSandboxArch() {
-#if defined(ARCH_CPU_ARM_FAMILY)
-  return "arm";
-#elif defined(ARCH_CPU_MIPS_FAMILY)
-  return "mips32";
-#elif defined(ARCH_CPU_X86_FAMILY)
-
-#if defined(OS_WIN)
-  // We have to check the host architecture on Windows.
-  // See sandbox_isa.h for an explanation why.
-  if (base::win::OSInfo::GetInstance()->architecture() ==
-      base::win::OSInfo::X64_ARCHITECTURE)
-    return "x86-64";
-  else
-    return "x86-32";
-#elif ARCH_CPU_64_BITS
-  return "x86-64";
-#else
-  return "x86-32";
-#endif  // defined(OS_WIN)
-
-#else
-#error Architecture not supported.
-#endif
-}
-
-}  // namespace nacl
diff --git a/components/nacl/renderer/sandbox_arch.h b/components/nacl/renderer/sandbox_arch.h
deleted file mode 100644
index e139b04..0000000
--- a/components/nacl/renderer/sandbox_arch.h
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2014 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.
-
-// Routines for determining the most appropriate NaCl executable for
-// the current CPU's architecture.
-
-#ifndef COMPONENTS_NACL_RENDERER_SANDBOX_ARCH_H
-#define COMPONENTS_NACL_RENDERER_SANDBOX_ARCH_H
-
-namespace nacl {
-// Returns the kind of SFI sandbox implemented by NaCl on this
-// platform.  See the implementation in sandbox_arch.cc for possible
-// values.
-const char* GetSandboxArch();
-}  // namespace nacl
-
-#endif  // COMPONENTS_NACL_RENDERER_SANDBOX_ARCH_H