Add support of x64 to generate .mk files

android_webview/tools/gyp_webview

Index: android_webview/tools/gyp_webview
diff --git a/android_webview/tools/gyp_webview b/android_webview/tools/gyp_webview
index ff39f6005e11d52415caf2e8863896f28dacf891..3714e0a2c0c349ea138e8fc4ff5dfb61304ee4d3 100755
--- a/android_webview/tools/gyp_webview
+++ b/android_webview/tools/gyp_webview
@@ -36,6 +36,8 @@ android_sdk=$(python -c \
     '${ANDROID_BUILD_TOP}')")
 DEFINES+=" android_src=\$(PWD)"
 DEFINES+=" android_ndk_root=ndk_root_unused_in_webview_build"
+DEFINES+=" android_ndk_sysroot=ndk_sysroot_unused_in_webview_build"
+DEFINES+=" android_gdbserver=gdbserver_unused_in_webview_build"

[Yang Gu, 2014/03/13 10:07:29]

We don't need to define them in common.gypi for the generation of webview
makefiles using ndk path. But if we don't explicitly define them here, error
would occur to report undefined variable in common.gypi.

One question here: Do we need to define gdbserver? I think it would be copied to
some apks for debug purpose. Will we generate some apks for test? Currently we
don't have x64 gdbserver in AOSP.

[Torne, 2014/03/13 11:04:46]

We don't define them for the other architectures, so I can't see why they would
need to be defined for x86_64. Where is the undefined variable reference?
The WebView gyp build never compiles any java code or generates any apks at all,
so this isn't ever needed.

[Yang Gu, 2014/03/13 16:06:07]

For 1st comment (take android_ndk_sysroot as example):
In common.gypi, we copy arch related variable out one scope with following code:
        # Copy conditionally-set variables out one scope.
        ...
        'android_ndk_sysroot%': '<(android_ndk_sysroot)',

Note this variable will not be used for the generation of webview makefiles (Not
sure if it's feasible/better to put it in condition "android_webview_build==0").
But if we don't define it either in gyp_webview or in conditionally-set code, it
will show the undefined variable error here. Other architectures don't show this
problem because they define it in conditionally-set code (take ia32 for example
as below) with "<(android_ndk_root)" (not expected). 
            ['target_arch == "ia32"', {
              'android_app_abi%': 'x86',
              'android_gdbserver%':
'<(android_ndk_root)/prebuilt/android-x86/gdbserver/gdbserver',
              'android_ndk_sysroot%':
'<(android_ndk_root)/platforms/android-14/arch-x86',
              'android_toolchain%':
'<(android_ndk_root)/toolchains/x86-4.6/prebuilt/<(host_os)-<(android_host_arch)/bin',
            }]

Still take the example to generate x86 webview makefiles, we run "gyp_webview
linux-x86". When parsing common.gypi, android_ndk_sysroot will be defined as
"<(android_ndk_root)/platforms/android-14/arch-x86", which is not correct as we
don't have ndk at all. We don't care its value as it would never be used to
generate makefile.


For 2nd comment:
I was just not sure if the generated makefiles can be used to generate apks such
as android_webview_test_apk and android_webview_unittests_apk. We use ndk to
generate them for sake of test.

[Torne, 2014/03/17 15:28:14]

If other architectures define these variables, then so should x64. WebView is
not the only build type; regular chromium needs to build on x64 too.
It's fine for this to refer to something that doesn't (currently) exist in the
NDK - it will in a future NDK release, I assume? As long as nothing in the build
actually refers to it, this isn't a problem.
No, the webview tests are built using the regular chromium build system and are
unrelated to android_webview_build=1. They are not testing the actual system
build of the webview, but a "public" SDK/NDK compatible build that's specific to
the webview test shell.

 DEFINES+=" android_sdk=\$(PWD)/${android_sdk}"
 DEFINES+=" android_sdk_root=\$(PWD)/${android_sdk}"
 DEFINES+=" android_sdk_version=sdk_version_unused_in_webview_build"
@@ -68,6 +70,9 @@ for host_os in linux mac; do
   if [ "$PLATFORM" == "${host_platform}-x86" -o "$PLATFORM" == "all" ]; then
     ${GYP} --suffix .${host_platform}-x86 ${EFLAGS} -Dtarget_arch=ia32
   fi
+  if [ "$PLATFORM" == "${host_platform}-x86_64" -o "$PLATFORM" == "all" ]; then
+    ${GYP} --suffix .${host_platform}-x86_64 ${EFLAGS} -Dtarget_arch=x64
+  fi
   if [ "$PLATFORM" == "${host_platform}-mips" -o "$PLATFORM" == "all" ]; then
     ${GYP} --suffix .${host_platform}-mips ${EFLAGS} -Dtarget_arch=mipsel
   fi