Only define NO_POSIX_MEMALIGN when needed

gyp/dng_sdk.gyp

Index: gyp/dng_sdk.gyp
diff --git a/gyp/dng_sdk.gyp b/gyp/dng_sdk.gyp
index 455990ba3d4a3b827ca6592ea7043d7aa3f64961..c49e6c45ccd74683c6dd20c7401a8245955ae843 100644
--- a/gyp/dng_sdk.gyp
+++ b/gyp/dng_sdk.gyp
@@ -8,7 +8,7 @@
   'target_name': 'dng_sdk-selector',
   'type': 'none',
   'conditions': [
-    [ 'skia_android_framework', {
+    ['skia_android_framework', {

[scroggo, 2016/01/28 16:28:53]

nit: This kind of change makes it harder to track changes with "git blame" and
doesn't (IMO) improve the code any.

[yujieqin, 2016/02/01 10:48:40]

reverted :)

         'dependencies': [ 'android_deps.gyp:libdng_sdk' ],
         'export_dependent_settings': [ 'android_deps.gyp:libdng_sdk' ],
       }, {
@@ -23,18 +23,25 @@
   'cflags': [
     '-fexceptions',
     '-w',
-    # FIXME: only disable ::posix_memalign() when needed.
-    '-DNO_POSIX_MEMALIGN'
   ],
-  'msvs_settings': {
-    'VCCLCompilerTool': {
-      'WarningLevel': '0',
-      'AdditionalOptions': ['/wd4189', ],
-    },
-  },
-  'xcode_settings': {
-    'WARNING_CFLAGS': ['-w'],
-  },
+  'conditions': [
+    ['skia_os == "android"', {
+      'cflags': ['-DNO_POSIX_MEMALIGN'],

[adaubert, 2016/01/28 15:57:54]

Could you please keep the "fixme" in the android case. We are ware of at least
one android system where this posix_memalign is not an issue.

[scroggo, 2016/01/28 16:28:53]

Any idea when/why it's needed? Is there a bug filed?

[adaubert, 2016/01/28 16:42:36]

Posix_memalign allocates page-aligned, to which extent this makes the DNG SDK
perform better compared to the alternatively used malloc, I don't know. And with
that I don't know if the work to fix this fixme is worth it.

From this point of view, we could also just keep this flag in for all cases, and
just remove the fixme, until we know it better.

[yujieqin, 2016/01/28 17:05:01]

@adaubert, I am not aware of any android could work with POSIX_MEMALIGN. Could
you be more specific here?

[adaubert, 2016/01/28 18:08:43]

As far as I remember posix_memalign works fine e.g. for the Nexus architectures.
But it does not work for the more exotic one like mips, neon.

[yujieqin, 2016/02/01 10:48:40]

It seems like the posix_memalign is added to android 17 and later. 

See
https://android-review.googlesource.com/#/c/107670/
https://android-review.googlesource.com/#/c/111658/

I will submit current change first, and dig this Android issue in following CLs.

+    }],
+    ['skia_os == "win"', {
+      'msvs_settings': {
+        'VCCLCompilerTool': {
+          'WarningLevel': '0',
+          'AdditionalOptions': ['/wd4189', ],
+        },
+      },
+    }],
+    ['skia_os == "ios" or skia_os == "mac"', {
+      'xcode_settings': {
+        'WARNING_CFLAGS': ['-w'],
+      },
+    }],
+  ],
   'dependencies': [
     'dng_dont_report_errors_flags',
     'dng_flags',