On windows, build zlib as a static library.

gyp/zlib.gyp

 # Copyright 2014 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
-  'targets': [{
-    'target_name': 'zlib',
-    'type': 'none',
-    'direct_dependent_settings': {
+  'targets': [
+  {
+    # Only used by win, down below.
+    'target_name' : 'zlib_x86_simd',

[mtklein, 2015/02/27 23:31:02]

Are there portable options for these?  I'm thinking ahead to older non-Windows
x86 compilers, and of course nacl, arm, and mips.

[scroggo, 2015/03/02 14:16:16]

IIUC, the portable versions are in the files where they are used. For example,
see
https://chromium.googlesource.com/chromium/src/third_party/zlib/+/master/defl...
fill_window.

+    'type': 'static_library',
+    'cflags' : ['-msse4.2', '-mpclmul'],
+    'sources' : [
+      '../third_party/externals/zlib/crc_folding.c',
+      '../third_party/externals/zlib/fill_window_sse.c',
+    ],
       'conditions': [
-        [ 'skia_android_framework', { 'include_dirs': [ 'external/zlib' ] }],
-        [ 'skia_os == "mac" or skia_os == "ios"', {
-            # XCode needs and explicit file path, not a logical name like -lz.
-            'link_settings': { 'libraries': [ '$(SDKROOT)/usr/lib/libz.dylib' ] },
-        },{
-            'link_settings': { 'libraries': [ '-lz' ] },
-        }]
+        ['skia_clang_build==1', {
+          'msvs_settings': {
+            'VCCLCompilerTool': {
+              'AdditionalOptions': [ '-msse4.2', '-mpclmul' ],
+            },
+          },
+        }],
       ],
-    },
-  },{
-    'target_name': 'miniz',
-    'type': 'none',
-    'direct_dependent_settings': {
-      'include_dirs': [ '../third_party/miniz' ],
-      'defines': [ 'ZLIB_INCLUDE="miniz.c"' ],
-      # Not ideal, but GCC's issuing an otherwise-unstoppable (but innocuous) warning from miniz.c
-      'cflags': [ '-w' ],
-    },
+  },
+  {
+      'target_name': 'zlib',
+      'direct_dependent_settings': {
+        'conditions': [
+          [ 'skia_android_framework', { 'include_dirs': [ 'external/zlib' ] }],
+          [ 'skia_os == "mac" or skia_os == "ios"', {
+              # XCode needs and explicit file path, not a logical name like -lz.
+              'link_settings': { 'libraries': [ '$(SDKROOT)/usr/lib/libz.dylib' ] },
+          }],
+          [ 'skia_os not in ["mac", "ios", "win"]',{

[mtklein, 2015/02/27 23:31:02]

If we're going to be building zlib, I'd feel more comfortable if we could use
our homebrewed version on as many platforms as possible.  Finding bugs on one
platform will help find bugs elsewhere, and it'll just generally make our output
more consistent.

I'm also okay with landing this as-is and tearing down the Windows-only
restrictions in a follow-up.

[scroggo, 2015/03/02 14:16:16]

Sounds fine to me. My preference is to land this as is so I can land SkPngCodec,
and then follow up.

+              'link_settings': { 'libraries': [ '-lz' ] },
+          }]
+        ],
+      },
+      'conditions': [
+        [ 'skia_os != "win"', {
+          'type': 'none',
+        }, {
+          # win
+          'type': 'static_library',
+          'sources': [
+            '../third_party/externals/zlib/adler32.c',
+            '../third_party/externals/zlib/compress.c',
+            '../third_party/externals/zlib/crc32.c',
+            '../third_party/externals/zlib/crc32.h',
+            '../third_party/externals/zlib/deflate.c',
+            '../third_party/externals/zlib/deflate.h',
+            '../third_party/externals/zlib/gzclose.c',
+            '../third_party/externals/zlib/gzguts.h',
+            '../third_party/externals/zlib/gzlib.c',
+            '../third_party/externals/zlib/gzread.c',
+            '../third_party/externals/zlib/gzwrite.c',
+            '../third_party/externals/zlib/infback.c',
+            '../third_party/externals/zlib/inffast.c',
+            '../third_party/externals/zlib/inffast.h',
+            '../third_party/externals/zlib/inffixed.h',
+            '../third_party/externals/zlib/inflate.c',
+            '../third_party/externals/zlib/inflate.h',
+            '../third_party/externals/zlib/inftrees.c',
+            '../third_party/externals/zlib/inftrees.h',
+            '../third_party/externals/zlib/mozzconf.h',
+            '../third_party/externals/zlib/trees.c',
+            '../third_party/externals/zlib/trees.h',
+            '../third_party/externals/zlib/uncompr.c',
+            '../third_party/externals/zlib/x86.h',
+            '../third_party/externals/zlib/x86.c',
+            '../third_party/externals/zlib/zconf.h',
+            '../third_party/externals/zlib/zlib.h',
+            '../third_party/externals/zlib/zutil.c',
+            '../third_party/externals/zlib/zutil.h',
+          ],
+          'include_dirs': [
+            '../third_party/externals/zlib/',
+          ],
+          'direct_dependent_settings': {
+            'include_dirs': [
+              '../third_party/externals/zlib',
+            ],
+          },
+          'dependencies': [
+            'zlib_x86_simd',
+          ],
+          'defines': [
+            '_CRT_NONSTDC_NO_DEPRECATE',
+          ],
+        }],
+      ],
   }],
 }