Revert "Remove third_party/binutils""

This reverts commit 9792bfb.

Reason for revert: Appears to have broken compile:
https://ci.chromium.org/p/chrome/builders/ci/chromeos-betty-pi-arc-chrome/6078
https://ci.chromium.org/p/chromium/builders/ci/chromeos-amd64-generic-rel/42623

Original change's description:
> Remove third_party/binutils"
> 
> R=​thakis
> CC=​thestig
> 
> Bug: 1067854
> Change-Id: I5e20c17210111c2f2c74888f45f4eb72172bca94
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2181970
> Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
> Commit-Queue: Ben Pastene <bpastene@chromium.org>
> Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
> Reviewed-by: Ben Pastene <bpastene@chromium.org>
> Reviewed-by: Nico Weber <thakis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#765766}

TBR=thakis@chromium.org,thomasanderson@chromium.org,bpastene@chromium.org

Change-Id: I3734b70cf81a08a845eb226023750b06de97e15f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1067854
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2183001
Reviewed-by: Scott Little <sclittle@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#765782}

.gn

@@ -340,6 +340,7 @@ check_targets = [
   "//third_party/ashmem/*",
   "//third_party/axe-core/*",
   "//third_party/bazel/*",
+  "//third_party/binutils/*",
   "//third_party/blanketjs/*",
 
   # "//third_party/blink/*",  # Errors: https://crbug.com/800764

DEPS

@@ -3695,6 +3695,18 @@ hooks = [
     'condition': 'checkout_mac',
     'action': ['python', 'src/build/mac_toolchain.py'],
   },
+  # Pull binutils for linux, enabled debug fission for faster linking /
+  # debugging when used with clang on Ubuntu Precise.
+  # https://code.google.com/p/chromium/issues/detail?id=352046
+  {
+    'name': 'binutils',
+    'pattern': 'src/third_party/binutils',
+    'condition': 'host_os == "linux" and host_cpu != "mips64"',
+    'action': [
+        'python',
+        'src/third_party/binutils/download.py',
+    ],
+  },
   {
     # Update the prebuilt clang toolchain.
     # Note: On Win, this should run after win_toolchain, as it may use it.

build/config/compiler/BUILD.gn

@@ -62,7 +62,7 @@ declare_args() {
 
   # When we are going to use gold we need to find it.
   # This is initialized below, after use_gold might have been overridden.
-  gold_path = ""
+  gold_path = false
 
   # Enable fatal linker warnings. Building Chromium with certain versions
   # of binutils can cause linker warning.
@@ -155,15 +155,30 @@ declare_args() {
   #
   # icf=all is broken in older golds, see
   # https://sourceware.org/bugzilla/show_bug.cgi?id=17704
+  # See also https://crbug.com/663886
+  # `linux_use_bundled_binutils` is to avoid breaking Linux distros which may
+  # still have a buggy gold.
   # chromeos binutils has been patched with the fix, so always use icf there.
   # The bug only affects x86 and x64, so we can still use ICF when targeting
   # other architectures.
   #
   # lld doesn't have the bug.
   use_icf = (is_posix || is_fuchsia) && !is_debug && !using_sanitizer &&
             !use_clang_coverage && !(is_android && use_order_profiling) &&
-            (use_lld || (use_gold && (is_chromeos || !(current_cpu == "x86" ||
-                                                       current_cpu == "x64"))))
+            (use_lld ||
+             (use_gold &&
+              ((!is_android && linux_use_bundled_binutils) || is_chromeos ||
+               !(current_cpu == "x86" || current_cpu == "x64"))))
+}
+
+# Apply the default logic for these values if they were not set explicitly.
+if (gold_path == false) {
+  if (use_gold) {
+    gold_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
+                            root_build_dir)
+  } else {
+    gold_path = ""
+  }
 }
 
 if (use_debug_fission == "default") {
@@ -405,19 +420,19 @@ config("compiler") {
       # On Android, this isn't needed.  gcc in the NDK knows to look next to
       # it with -fuse-ld=gold, and clang gets a --gcc-toolchain flag passed
       # above.
-      if (gold_path != "") {
-        ldflags += [ "-B$gold_path" ]
-      }
+      ldflags += [ "-B$gold_path" ]
 
-      ldflags += [
-        # Experimentation found that using four linking threads
-        # saved ~20% of link time.
-        # https://groups.google.com/a/chromium.org/group/chromium-dev/browse_thread/thread/281527606915bb36
-        # Only apply this to the target linker, since the host
-        # linker might not be gold, but isn't used much anyway.
-        "-Wl,--threads",
-        "-Wl,--thread-count=4",
-      ]
+      if (linux_use_bundled_binutils) {
+        ldflags += [
+          # Experimentation found that using four linking threads
+          # saved ~20% of link time.
+          # https://groups.google.com/a/chromium.org/group/chromium-dev/browse_thread/thread/281527606915bb36
+          # Only apply this to the target linker, since the host
+          # linker might not be gold, but isn't used much anyway.
+          "-Wl,--threads",
+          "-Wl,--thread-count=4",
+        ]
+      }
     }
 
     # TODO(thestig): Make this flag work with GN.
@@ -426,12 +441,20 @@ config("compiler") {
     #    "-Wl,--detect-odr-violations",
     #  ]
     #}
+  } else if (linux_use_bundled_binutils) {
+    # Gold is the default linker for the bundled binutils so we explicitly
+    # enable the bfd linker when use_gold is not set.
+    ldflags += [ "-fuse-ld=bfd" ]
   }
 
   if (use_icf) {
     ldflags += [ "-Wl,--icf=all" ]
   }
 
+  if (linux_use_bundled_binutils) {
+    cflags += [ "-B$binutils_path" ]
+  }
+
   if (is_linux) {
     cflags += [ "-pthread" ]
     # Do not use the -pthread ldflag here since it becomes a no-op

build/config/compiler/compiler.gni

@@ -42,6 +42,16 @@ declare_args() {
   # example, don't omit the frame pointer and leave in symbols.
   enable_profiling = false
 
+  # Whether to use the binary binutils checked into third_party/binutils.
+  # These are not multi-arch so cannot be used except on x86 and x86-64 (the
+  # only two architectures that are currently checked in). Turn this off when
+  # you are using a custom toolchain and need to control -B in cflags.
+  linux_use_bundled_binutils =
+      linux_use_bundled_binutils_override && is_linux &&
+      (current_cpu == "x64" || current_cpu == "x86")
+  binutils_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
+                              root_build_dir)
+
   # use_debug_fission: whether to use split DWARF debug info
   # files. This can reduce link time significantly, but is incompatible
   # with some utilities such as icecc and ccache. Requires gold and

build/toolchain/cros_toolchain.gni

@@ -55,8 +55,8 @@ declare_args() {
   cros_host_cc = "${clang_base_path}/bin/clang"
   cros_host_cxx = "${clang_base_path}/bin/clang++"
   cros_host_is_clang = true
-  cros_host_nm = ""
-  cros_host_readelf = ""
+  cros_host_nm = "${binutils_path}/nm"
+  cros_host_readelf = "${binutils_path}/readelf"
   cros_host_extra_cflags = ""
   cros_host_extra_cppflags = ""
   cros_host_extra_cxxflags = ""
@@ -67,8 +67,8 @@ declare_args() {
   cros_v8_snapshot_cc = "${clang_base_path}/bin/clang"
   cros_v8_snapshot_cxx = "${clang_base_path}/bin/clang++"
   cros_v8_snapshot_is_clang = true
-  cros_v8_snapshot_nm = ""
-  cros_v8_snapshot_readelf = ""
+  cros_v8_snapshot_nm = "${binutils_path}/nm"
+  cros_v8_snapshot_readelf = "${binutils_path}/readelf"
   cros_v8_snapshot_extra_cflags = ""
   cros_v8_snapshot_extra_cppflags = ""
   cros_v8_snapshot_extra_cxxflags = ""

build_overrides/build.gni

@@ -12,6 +12,9 @@ import("//build/config/gclient_args.gni")
 # Some non-Chromium builds don't support building java targets.
 enable_java_templates = true
 
+# Some non-Chromium builds don't use Chromium's third_party/binutils.
+linux_use_bundled_binutils_override = true
+
 # Allows different projects to specify their own suppressions and blacklist
 # files for sanitizer tools.
 # asan_suppressions_file = "path/to/asan_suppressions.cc"

docs/linux/build_instructions.md

@@ -183,6 +183,7 @@ it. e.g. Intel, Opera, Samsung (this is not useful if you're using Goma).
 In order to use `icecc`, set the following GN args:
 
 ```
+linux_use_bundled_binutils=false
 use_debug_fission=false
 is_clang=false
 ```

testing/buildbot/trybot_analyze_config.json

@@ -85,7 +85,8 @@
     "exclusions": [
       "build/linux/sysroot_ld_path.sh",
       "build/linux/sysroot_scripts/sysroots.json",
-      "testing/xvfb.py"
+      "testing/xvfb.py",
+      "third_party/binutils/Linux_x64/binutils.tar.bz2.sha1"
     ]
   },
   "win": {

third_party/binutils/.gitignore

@@ -0,0 +1,8 @@
+binutils-*
+*-chroot-*
+output-*
+Linux_ia32/*stamp*
+Linux_ia32/*tar.bz2
+Linux_x64/*stamp*
+Linux_x64/*tar.bz2
+*/Release