Port cfi configuration from chromium.

BUG=chromium:515782
LOG=n

Review URL: https://codereview.chromium.org/1267773004

Cr-Commit-Position: refs/heads/master@{#30058}

build/download_gold_plugin.py

+#!/usr/bin/env python
+# Copyright 2015 the V8 project authors. All rights reserved.
+# Copyright 2015 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.
+
+"""Script to download LLVM gold plugin from google storage."""
+
+import json
+import os
+import shutil
+import subprocess
+import sys
+import zipfile
+
+SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
+CHROME_SRC = os.path.abspath(os.path.join(SCRIPT_DIR, os.pardir))
+sys.path.insert(0, os.path.join(CHROME_SRC, 'tools'))
+
+import find_depot_tools
+
+DEPOT_PATH = find_depot_tools.add_depot_tools_to_path()
+GSUTIL_PATH = os.path.join(DEPOT_PATH, 'gsutil.py')
+
+LLVM_BUILD_PATH = os.path.join(CHROME_SRC, 'third_party', 'llvm-build',
+                               'Release+Asserts')
+CLANG_UPDATE_PY = os.path.join(CHROME_SRC, 'tools', 'clang', 'scripts',
+                               'update.py')
+CLANG_REVISION = os.popen(CLANG_UPDATE_PY + ' --print-revision').read().rstrip()
+
+CLANG_BUCKET = 'gs://chromium-browser-clang/Linux_x64'
+
+def main():
+  targz_name = 'llvmgold-%s.tgz' % CLANG_REVISION
+  remote_path = '%s/%s' % (CLANG_BUCKET, targz_name)
+
+  os.chdir(LLVM_BUILD_PATH)
+
+  # TODO(pcc): Fix gsutil.py cp url file < /dev/null 2>&0
+  # (currently aborts with exit code 1,
+  # https://github.com/GoogleCloudPlatform/gsutil/issues/289) or change the
+  # stdin->stderr redirect in update.py to do something else (crbug.com/494442).
+  subprocess.check_call(['python', GSUTIL_PATH,
+                         'cp', remote_path, targz_name],
+                        stderr=open('/dev/null', 'w'))
+  subprocess.check_call(['tar', 'xzf', targz_name])
+  os.remove(targz_name)
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(main())

build/standalone.gypi

@@ -88,6 +88,13 @@
 
       'clang_dir%': '<(base_dir)/third_party/llvm-build/Release+Asserts',
 
+      'use_lto%': 0,
+
+      # Control Flow Integrity for virtual calls and casts.
+      # See http://clang.llvm.org/docs/ControlFlowIntegrity.html
+      'cfi_vptr%': 0,
+      'cfi_diag%': 0,
+
       # goma settings.
       # 1 to use goma.
       # If no gomadir is set, it uses the default gomadir.
@@ -105,6 +112,16 @@
         }, {
           'host_clang%': '0',
         }],
+        # linux_use_bundled_gold: whether to use the gold linker binary checked
+        # into third_party/binutils.  Force this off via GYP_DEFINES when you
+        # are using a custom toolchain and need to control -B in ldflags.
+        # Do not use 32-bit gold on 32-bit hosts as it runs out address space
+        # for component=static_library builds.
+        ['(OS=="linux" or OS=="android") and (target_arch=="x64" or target_arch=="arm" or (target_arch=="ia32" and host_arch=="x64"))', {
+          'linux_use_bundled_gold%': 1,
+        }, {
+          'linux_use_bundled_gold%': 0,
+        }],
       ],
     },
     'base_dir%': '<(base_dir)',
@@ -122,6 +139,10 @@
     'tsan%': '<(tsan)',
     'sanitizer_coverage%': '<(sanitizer_coverage)',
     'use_custom_libcxx%': '<(use_custom_libcxx)',
+    'linux_use_bundled_gold%': '<(linux_use_bundled_gold)',
+    'use_lto%': '<(use_lto)',
+    'cfi_vptr%': '<(cfi_vptr)',
+    'cfi_diag%': '<(cfi_diag)',
 
     # Add a simple extra solely for the purpose of the cctests
     'v8_extra_library_files': ['../test/cctest/test-extra.js'],
@@ -207,6 +228,9 @@
         # the C++ standard library is used.
         'use_custom_libcxx%': 1,
       }],
+      ['cfi_vptr==1', {
+        'use_lto%': 1,
+      }],
       ['OS=="linux"', {
         # Gradually roll out v8_use_external_startup_data.
         # Should eventually be default enabled on all platforms.
@@ -535,6 +559,21 @@
               }],
             ],
           }],
+          ['linux_use_bundled_gold==1 and not (clang==0 and use_lto==1)', {
+            # Put our binutils, which contains gold in the search path. We pass
+            # the path to gold to the compiler. gyp leaves unspecified what the
+            # cwd is when running the compiler, so the normal gyp path-munging
+            # fails us. This hack gets the right path.
+            #
+            # Disabled when using GCC LTO because GCC also uses the -B search
+            # path at link time to find "as", and our bundled "as" can only
+            # target x86.
+            'ldflags': [
+              # Note, Chromium allows ia32 host arch as well, we limit this to
+              # x64 in v8.
+              '-B<(base_dir)/third_party/binutils/Linux_x64/Release/bin',
+            ],
+          }],
         ],
       },
     }],
@@ -1144,5 +1183,100 @@
        ['CXX.host_wrapper', '<(gomadir)/gomacc'],
       ],
     }],
+    ['use_lto==1', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'cflags': [
+              '-flto',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['use_lto==1 and clang==0', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'cflags': [
+              '-ffat-lto-objects',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['use_lto==1 and clang==1', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'arflags': [
+              '--plugin', '<(clang_dir)/lib/LLVMgold.so',
+            ],
+            # Apply a lower optimization level with lto. Chromium does this
+            # for non-official builds only - a differentiation that doesn't
+            # exist in v8.
+            'ldflags': [
+              '-Wl,--plugin-opt,O1',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['use_lto==1 and clang==0', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'ldflags': [
+              '-flto=32',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['use_lto==1 and clang==1', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'ldflags': [
+              '-flto',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['cfi_diag==1', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'cflags': [
+              '-fno-sanitize-trap=cfi',
+              '-fsanitize-recover=cfi',
+            ],
+            'ldflags': [
+              '-fno-sanitize-trap=cfi',
+              '-fsanitize-recover=cfi',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['cfi_vptr==1', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'cflags': [
+              '-fsanitize=cfi-vcall',
+              '-fsanitize=cfi-derived-cast',
+              '-fsanitize=cfi-unrelated-cast',
+            ],
+            'ldflags': [
+              '-fsanitize=cfi-vcall',
+              '-fsanitize=cfi-derived-cast',
+              '-fsanitize=cfi-unrelated-cast',
+            ],
+          }],
+        ],
+      },
+    }],
   ],
 }