Always install default host sysroots from gclient runhooks

build/linux/sysroot_scripts/install-sysroot.py

Index: build/linux/sysroot_scripts/install-sysroot.py
diff --git a/build/linux/sysroot_scripts/install-sysroot.py b/build/linux/sysroot_scripts/install-sysroot.py
index e922cb7a9f33ed3b0459b7b8c83f32f97c0ca6af..f5993b919b5d8333b869f1bf88ed0cde4b0796e2 100755
--- a/build/linux/sysroot_scripts/install-sysroot.py
+++ b/build/linux/sysroot_scripts/install-sysroot.py
@@ -65,7 +65,7 @@ def GetSha1(filename):
   return sha1.hexdigest()
 
 
-def DetectArch(gyp_defines, is_android):
+def DetectArch(gyp_defines):
   # Check for optional target_arch and only install for that architecture.
   # If target_arch is not specified, then only install for the host
   # architecture.
@@ -83,9 +83,6 @@ def DetectArch(gyp_defines, is_android):
   elif target_arch:
     raise Exception('Unrecognized target_arch: %s' % target_arch)
 
-  if is_android:
-    return 'arm'
-
   # Figure out host arch using build/detect_host_arch.py and
   # set target_arch to host arch
   detected_host_arch = detect_host_arch.HostArch()
@@ -107,31 +104,27 @@ def main():
   if options.running_as_hook and not sys.platform.startswith('linux'):
     return 0
 
+  # TODO(agrieve): Stop using GYP_DEFINES and ensure bots that cross-compile
+  #     explicitly download sysroots.

[Dirk Pranke, 2015/12/02 23:09:22]

I don't think we want a bot-only solution, so this comment is not what 
I would write.

I would change the comment to something like TODO: make this not depend on 
GYP_DEFINES so that it works w/ GN as well.

[agrieve, 2015/12/03 02:06:24]

Done.

   gyp_environment.SetEnvironment()
   supplemental_includes = gyp_chromium.GetSupplementalFiles()
   gyp_defines = gyp_chromium.GetGypVars(supplemental_includes)
-  is_android = gyp_defines.get('OS') == 'android'
-
-  if (options.running_as_hook and (not is_android) and
-      (gyp_defines.get('chromeos') or gyp_defines.get('use_sysroot') == '0')):
-    return 0

[Sam Clegg, 2015/12/02 23:17:46]

Why not keep this early out?

[agrieve, 2015/12/03 02:06:24]

Because you might have built with both GYP and GN in the same checkout, and your
GN might require a sysroot while your GYP does not.

 
   if options.arch:
     target_arch = options.arch
   else:
-    target_arch = DetectArch(gyp_defines, is_android)
+    target_arch = DetectArch(gyp_defines)
     if not target_arch:
       print 'Unable to detect target architecture'
       return 1
 
-  if is_android:
-    # 32-bit Android builds require a 32-bit host sysroot for the v8 snapshot.
-    if '64' not in target_arch:
+    if target_arch == 'amd64':

[Sam Clegg, 2015/12/02 23:17:46]

Won't target_arch be 'arm' here for most android bots?

[Dirk Pranke, 2015/12/02 23:20:38]

Not necessarily. The bots don't have to set target_arch=arm, because that's the
default if os=android. Some might, some might not.

That said, we should probably make sure anyone that *does* set target_arch=arm
also still gets the host sysroots,
so I think you're actually right that this patch is in fact wrong.

[agrieve, 2015/12/03 02:06:24]

Reworked this to look for the presence of //third_party/android_tools instead.

+      # 32-bit Android builds (the default) require a 32-bit host sysroot for
+      # the v8 snapshot, and a 64-bit sysroot for host tools. Assume 'amd64'
+      # means default setup.

[Dirk Pranke, 2015/12/02 23:09:22]

I don't think it's really clear what "(the default)" means in this situation.
32-bit android builds are the default *android* build, but in no sense is an
android build the default build for linux hosts generally.

I would rewrite this comment to something along the lines of "we don't have a
good way as a gclient hook to figure out which of the sysroots we need, so
install both of them to make both desktop linux builds and android builds
happy".

[agrieve, 2015/12/03 02:06:24]

reworded.

       ret = _InstallSysroot('i386')
       if ret:
         return ret
-    # Always need host sysroot (which we assume is x64).
-    target_arch = 'amd64'
 
   return _InstallSysroot(target_arch)