Build for Android from Windows, work in progress.

Pretty vanilla stuff here, mostly just making the gcc-like toolchain Windows friendly.

I was having trouble getting rm -r {{output}} && $ar rcs {{output}} @$rspfile to work without deleting my ar.exe, so I chickened out the usual way by adding gn/ar.py.

I've also updated bin/droid to work with Git Bash on Windows.

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3751

Change-Id: I04c34ccc91e6a291c11ac4e7a7a0ffe41d879fe6
Reviewed-on: https://skia-review.googlesource.com/3751
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>

bin/droid

@@ -16,6 +16,7 @@ args=$@
 set -e
 set -x
 
-adb push $path /data/local/tmp/
-adb push resources /data/local/tmp/
-adb shell "cd /data/local/tmp; ./$name $args"
+adb push $path //data/local/tmp/
+adb push resources //data/local/tmp/
+adb shell "chmod +x //data/local/tmp/$name"
+adb shell "cd //data/local/tmp; ./$name $args"

gn/BUILD.gn

@@ -12,6 +12,11 @@ declare_args() {
     ar = "$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin/ar"
     cc = "$ndk/toolchains/llvm/prebuilt/$ndk_host/bin/clang"
     cxx = "$ndk/toolchains/llvm/prebuilt/$ndk_host/bin/clang++"
+    if (host_os == "win") {
+      ar = ar + ".exe"
+      cc = cc + ".exe"
+      cxx = cxx + ".exe"
+    }
   }
 
   windk = "C:/Program Files (x86)/Microsoft Visual Studio 14.0"
@@ -24,6 +29,14 @@ declare_args() {
   cc_wrapper = ""
 }
 
+if (host_os == "win") {
+  python = "python.bat"
+  stamp = "cmd.exe /c echo >"
+} else {
+  python = "python"
+  stamp = "touch"
+}
+
 if (!is_win) {
   is_clang = exec_script("is_clang.py",
                          [
@@ -465,13 +478,13 @@ toolchain("msvc") {
   }
 
   tool("stamp") {
-    command = "cmd.exe /c echo > {{output}}"
+    command = "$stamp {{output}}"
     description = "stamp {{output}}"
   }
 
   tool("copy") {
     cp_py = rebase_path("cp.py")
-    command = "python.bat $cp_py {{source}} {{output}}"
+    command = "$python $cp_py {{source}} {{output}}"
     description = "copy {{source}} {{output}}"
   }
 }
@@ -531,7 +544,15 @@ toolchain("gcc_like") {
   }
 
   tool("alink") {
-    command = "rm -f {{output}} && $ar rcs {{output}} {{inputs}}"
+    if (host_os == "win") {
+      rspfile = "{{output}}.rsp"
+      rspfile_content = "{{inputs}}"
+      ar_py = rebase_path("ar.py")
+      command = "$python $ar_py $ar {{output}} $rspfile"
+    } else {
+      # We'd use ar.py all the time, but Mac ar doesn't support @rspfile syntax.  :(
+      command = "rm -f {{output}} && $ar rcs {{output}} {{inputs}}"
+    }
     outputs = [
       "{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
     ]
@@ -566,13 +587,13 @@ toolchain("gcc_like") {
   }
 
   tool("stamp") {
-    command = "touch {{output}}"
+    command = "$stamp {{output}}"
     description = "stamp {{output}}"
   }
 
   tool("copy") {
     cp_py = rebase_path("cp.py")
-    command = "python $cp_py {{source}} {{output}}"
+    command = "$python $cp_py {{source}} {{output}}"
     description = "copy {{source}} {{output}}"
   }
 }

gn/BUILDCONFIG.gn

@@ -59,6 +59,8 @@ if (is_android) {
     ndk_host = "linux-x86_64"
   } else if (host_os == "mac") {
     ndk_host = "darwin-x86_64"
+  } else if (host_os == "win") {
+    ndk_host = "windows-x86_64"
   }
 
   if (target_cpu == "arm64") {

gn/ar.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+#
+# Copyright 2016 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import subprocess
+import sys
+
+# Equivalent to: rm -f $2 && $1 rcs $2 @$3
+
+ar, output, rspfile = sys.argv[1:]
+
+if os.path.exists(output):
+  os.remove(output)
+sys.exit(subprocess.call([ar, "rcs", output, "@" + rspfile]))