Linux: Switch 32-bit official builds to use the bundled 64-bit linker.

It is assumed that even though the buildbots have 32-bit userland,
they also have a 64-bit kernel and a 64-bit libc installed.

BUG=366523

Review URL: https://codereview.chromium.org/255023003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266729 0039d316-1c4b-4281-b951-d872f2087c98

build/common.gypi

@@ -729,8 +729,8 @@
         # 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.
-        # Gold is not used for 32-bit linux builds as it runs out of address
-        # space.
+        # Do not use 32-bit gold on 32-bit hosts as it runs out address space
+        # for component=static_library builds.
         ['OS=="linux" and (target_arch=="x64" or target_arch=="arm")', {
           'linux_use_bundled_gold%': 1,
         }, {
@@ -1445,6 +1445,16 @@
             # Omit unwind support in official release builds to save space. We
             # can use breakpad for these builds.
             'release_unwind_tables%': 0,
+
+            'conditions': [
+              # For official builds, use a 64-bit linker to avoid running out
+              # of address space. The buildbots should have a 64-bit kernel
+              # and a 64-bit libc installed.
+              ['host_arch=="ia32" and target_arch=="ia32"', {
+                'linux_use_bundled_gold%': '1',
+                'binutils_dir%': 'third_party/binutils/Linux_x64/Release/bin',
+              }],
+            ],
           }],
         ],
       }],  # os_posix==1 and OS!="mac" and OS!="ios"
@@ -3795,16 +3805,14 @@
           ['linux_dump_symbols==1', {
             'cflags': [ '-g' ],
             'conditions': [
-              # TODO(thestig) We should not need to specify chromeos==0 here,
-              # but somehow ChromeOS uses gold despite linux_use_bundled_gold==0.
-              # http://crbug.com./360082
-              ['linux_use_bundled_gold==0 and chromeos==0 and OS!="android"', {
+              ['OS=="linux" and host_arch=="ia32" and linux_use_bundled_gold==0', {
                 'target_conditions': [
                   ['_toolset=="target"', {
                     'ldflags': [
-                      # Workarounds for linker OOM.
+                      # Attempt to use less memory to prevent the linker from
+                      # running out of address space. Considering installing a
+                      # 64-bit kernel and switching to a 64-bit linker.
                       '-Wl,--no-keep-memory',
-                      '-Wl,--reduce-memory-overheads',
                     ],
                   }],
                 ],

third_party/binutils/download.py

@@ -47,17 +47,14 @@ def GetArch():
   return subprocess.check_output(['python', DETECT_HOST_ARCH]).strip()
 
 
-def main(args):
-  if not sys.platform.startswith('linux'):
-    return 0
-
-  archdir = os.path.join(BINUTILS_DIR, 'Linux_' + GetArch())
+def FetchAndExtract(arch):
+  archdir = os.path.join(BINUTILS_DIR, 'Linux_' + arch)
   tarball = os.path.join(archdir, BINUTILS_FILE)
   outdir = os.path.join(archdir, BINUTILS_OUT)
 
   sha1file = tarball + '.sha1'
   if not os.path.exists(sha1file):
-    print "WARNING: No binutils found for your architecture (%s)!" % GetArch()
+    print "WARNING: No binutils found for your architecture (%s)!" % arch
     return 0
 
   checksum = ReadFile(sha1file)
@@ -96,5 +93,22 @@ def main(args):
   return 0
 
 
+def main(args):
+  if not sys.platform.startswith('linux'):
+    return 0
+
+  arch = GetArch()
+  if arch == 'x64':
+    return FetchAndExtract(arch)
+  if arch == 'ia32':
+    ret = FetchAndExtract(arch)
+    if ret != 0:
+      return ret
+    # Fetch the x64 toolchain as well for official bots with 64-bit kernels.
+    return FetchAndExtract('x64')
+  print "Host architecture %s is not supported." % arch
+  return 1
+
+
 if __name__ == '__main__':
   sys.exit(main(sys.argv))