Compile the skia library for windows using gn.

gn/BUILD.gn

 # Copyright 2016 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 declare_args() {
   ar = "ar"
   cc = "cc"
   cxx = "c++"
 
   if (is_android) {
     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++"
   }
 
   extra_cflags = ""
   extra_cflags_c = ""
   extra_cflags_cc = ""
   extra_ldflags = ""
 
   compiler_prefix = ""
 }
 
-config("no_rtti") {
-  if (sanitize != "ASAN") {  # -fsanitize=vptr requires RTTI
-    cflags_cc = [ "-fno-rtti" ]
+if (is_win) {
+  config("default") {
+    cflags = [
+      "/Gy",      # Enable function-level linking.

[mtklein, 2016/09/14 21:25:14]

If there is any doubt, let's leave it out.

[herb_g, 2016/09/16 19:54:15]

Done.

+      "/FS",      # Preserve previous PDB behavior.
+      "/bigobj",  # Some of our files are bigger than the regular limits.
+    ]
+    cflags_c = ["/TC"]
+    cflags_cc = ["/TP"]
+    defines = [
+          "_HAS_EXCEPTIONS=0",
+          "WIN32_LEAN_AND_MEAN",
+          "NOMINMAX",
+    ]
+  }
+
+  config("no_rtti") {
+  }
+  
+  config("executable") {
+
+  }
+} else {
+  config("default") {
+    cflags = [
+      "-O1",
+      "-fstrict-aliasing",
+      "-fPIC",
+      "-fvisibility=hidden",
+
+      "-Werror",
+      "-Wall",
+      "-Wextra",
+      "-Winit-self",
+      "-Wpointer-arith",
+      "-Wsign-compare",
+      "-Wvla",
+
+      "-Wno-deprecated-declarations",
+      "-Wno-unused-parameter",
+    ]
+    cflags_cc = [
+      "-std=c++11",
+      "-fno-exceptions",
+      "-fno-threadsafe-statics",
+      "-fvisibility-inlines-hidden",
+
+      "-Wnon-virtual-dtor",
+    ]
+    ldflags = []
+
+    # It's annoying to wait for full debug symbols to push over
+    # to Android devices.  -gline-tables-only is a lot slimmer.
+    if (is_android) {

[mtklein, 2016/09/14 21:25:14]

This needs some rebasing.

[herb_g, 2016/09/16 19:54:15]

Done.

+      cflags += [ "-gline-tables-only" ]
+    } else {
+      cflags += [ "-g" ]
+    }
+
+    if (current_cpu == "arm") {
+      cflags += [
+        "-march=armv7-a",
+        "-mfpu=neon",
+        "-mthumb",
+      ]
+    } else if (current_cpu == "mipsel") {
+      cflags += [
+        "-march=mips32r2",
+        "-mdspr2",
+      ]
+    }
+
+    if (is_android) {
+      asmflags = [
+        "--target=$ndk_target",
+        "-B$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin",
+      ]
+      cflags += [
+        "--sysroot=$ndk/platforms/$ndk_platform",
+        "--target=$ndk_target",
+        "-B$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin",
+      ]
+      cflags_cc += [
+        "-isystem$ndk/sources/android/support/include",
+        "-isystem$ndk/sources/cxx-stl/llvm-libc++/libcxx/include",
+      ]
+      ldflags += [
+        "--sysroot=$ndk/platforms/$ndk_platform",
+        "--target=$ndk_target",
+        "-B$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin",
+        "-pie",
+      ]
+      lib_dirs = [
+        "$ndk/sources/cxx-stl/llvm-libc++/libs/$ndk_stdlib",
+        "$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/lib/gcc/$ndk_target/4.9.x",
+      ]
+      libs = [
+        # Order matters here!  Keep these three in exactly this order.
+        "c++_static",
+        "c++abi",
+        "android_support",
+      ]
+      if (target_cpu == "arm") {
+        libs += [ "unwind" ]
+      }
+    }
+
+    if (is_linux) {
+      libs = [ "pthread" ]

[mtklein, 2016/09/14 21:25:14]

This is the source of our global pthread power. 

[herb_g, 2016/09/16 19:54:15]

Done.

+    }
+
+    if (sanitize != "") {
+      # You can either pass the sanitizers directly, e.g. "address,undefined",
+      # or pass one of the couple common aliases used by the bots.
+      sanitizers = sanitize
+      if (sanitize == "ASAN") {
+        sanitizers = "address,bool,function,integer-divide-by-zero,nonnull-attribute,null,object-size,return,returns-nonnull-attribute,shift,signed-integer-overflow,unreachable,vla-bound,vptr"
+      } else if (sanitize == "TSAN") {
+        sanitizers = "thread"
+      } else if (sanitize == "MSAN") {
+        sanitizers = "memory"
+      }
+
+      cflags += [
+        "-fsanitize=$sanitizers",
+        "-fno-sanitize-recover=$sanitizers",
+        "-fsanitize-blacklist=" + rebase_path("../tools/xsan.blacklist"),
+      ]
+      ldflags += [ "-fsanitize=$sanitizers" ]
+      if (sanitizers == "memory") {
+        cflags += [ "-fsanitize-memory-track-origins" ]
+        cflags_cc += [ "-stdlib=libc++" ]
+        ldflags += [ "-stdlib=libc++" ]
+      }
+    }
+  }
+
+  config("no_rtti") {
+    if (sanitize != "ASAN") {  # -fsanitize=vptr requires RTTI
+      cflags_cc = [ "-fno-rtti" ]
+    }
+  }
+
+  config("release") {
+    cflags = [ "-O3" ]
+    defines = [ "NDEBUG" ]
+  }
+
+  config("executable") {
+    if (is_mac) {
+      ldflags = [ "-Wl,-rpath,@loader_path/." ]
+    } else if (is_linux) {
+      ldflags = [ "-Wl,-rpath,\$ORIGIN" ]
+    }
   }
 }
 
-config("default") {
-  cflags = [
-    "-O1",
-    "-fstrict-aliasing",
-    "-fPIC",
-    "-fvisibility=hidden",
-
-    "-Werror",
-    "-Wall",
-    "-Wextra",
-    "-Winit-self",
-    "-Wpointer-arith",
-    "-Wsign-compare",
-    "-Wvla",
-
-    "-Wno-deprecated-declarations",
-    "-Wno-unused-parameter",
-  ]
-  cflags_cc = [
-    "-std=c++11",
-    "-fno-exceptions",
-    "-fno-threadsafe-statics",
-    "-fvisibility-inlines-hidden",
-
-    "-Wnon-virtual-dtor",
-  ]
-  ldflags = []
-
-  # It's annoying to wait for full debug symbols to push over
-  # to Android devices.  -gline-tables-only is a lot slimmer.
-  if (is_android) {
-    cflags += [ "-gline-tables-only" ]
-  } else {
-    cflags += [ "-g" ]
-  }
-
-  if (current_cpu == "arm") {
-    cflags += [
-      "-march=armv7-a",
-      "-mfpu=neon",
-      "-mthumb",
-    ]
-  } else if (current_cpu == "mipsel") {
-    cflags += [
-      "-march=mips32r2",
-      "-mdspr2",
-    ]
-  }
-
-  if (is_android) {
-    asmflags = [
-      "--target=$ndk_target",
-      "-B$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin",
-    ]
-    cflags += [
-      "--sysroot=$ndk/platforms/$ndk_platform",
-      "--target=$ndk_target",
-      "-B$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin",
-    ]
-    cflags_cc += [
-      "-isystem$ndk/sources/android/support/include",
-      "-isystem$ndk/sources/cxx-stl/llvm-libc++/libcxx/include",
-    ]
-    ldflags += [
-      "--sysroot=$ndk/platforms/$ndk_platform",
-      "--target=$ndk_target",
-      "-B$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin",
-      "-pie",
-    ]
-    lib_dirs = [
-      "$ndk/sources/cxx-stl/llvm-libc++/libs/$ndk_stdlib",
-      "$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/lib/gcc/$ndk_target/4.9.x",
-    ]
-    libs = [
-      # Order matters here!  Keep these three in exactly this order.
-      "c++_static",
-      "c++abi",
-      "android_support",
-    ]
-    if (target_cpu == "arm") {
-      libs += [ "unwind" ]
-    }
-  }
-
-  if (is_linux) {
-    libs = [ "pthread" ]
-  }
-
-  if (sanitize != "") {
-    # You can either pass the sanitizers directly, e.g. "address,undefined",
-    # or pass one of the couple common aliases used by the bots.
-    sanitizers = sanitize
-    if (sanitize == "ASAN") {
-      sanitizers = "address,bool,function,integer-divide-by-zero,nonnull-attribute,null,object-size,return,returns-nonnull-attribute,shift,signed-integer-overflow,unreachable,vla-bound,vptr"
-    } else if (sanitize == "TSAN") {
-      sanitizers = "thread"
-    } else if (sanitize == "MSAN") {
-      sanitizers = "memory"
-    }
-
-    cflags += [
-      "-fsanitize=$sanitizers",
-      "-fno-sanitize-recover=$sanitizers",
-      "-fsanitize-blacklist=" + rebase_path("../tools/xsan.blacklist"),
-    ]
-    ldflags += [ "-fsanitize=$sanitizers" ]
-    if (sanitizers == "memory") {
-      cflags += [ "-fsanitize-memory-track-origins" ]
-      cflags_cc += [ "-stdlib=libc++" ]
-      ldflags += [ "-stdlib=libc++" ]
-    }
-  }
+toolchain("msvc") {
+
+    tool("cc") {
+      rspfile = "{{output}}.rsp"
+      precompiled_header_type = "msvc"
+      pdbname = "{{target_out_dir}}/{{label_name}}_c.pdb"
+
+      # Label names may have spaces in them so the pdbname must be quoted. The
+      # source and output don't need to be quoted because GN knows they're a
+      # full file name and will quote automatically when necessary.
+      command = "ninja -t msvc -e environment.x64 -- C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64\cl.exe /nologo /showIncludes /FC @$rspfile /c {{source}} /Fo{{output}} /Fd\"$pdbname\""
+      depsformat = "msvc"
+      description = "CC {{output}}"
+      outputs = [
+        "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.obj",
+        # "$object_subdir/{{source_name_part}}.obj",

[mtklein, 2016/09/14 21:25:14]

Probably can clean up these working drafts.

[herb_g, 2016/09/16 19:54:15]

Done.

+      ]
+      rspfile_content = "{{defines}} {{include_dirs}} {{cflags}} {{cflags_c}}"
+    }
+
+    tool("cxx") {
+      rspfile = "{{output}}.rsp"
+      precompiled_header_type = "msvc"
+      pdbname = "{{target_out_dir}}/{{label_name}}_c.pdb"
+
+      # Label names may have spaces in them so the pdbname must be quoted. The
+      # source and output don't need to be quoted because GN knows they're a
+      # full file name and will quote automatically when necessary.
+      command = "ninja -t msvc -e environment.x64 -- C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64\cl.exe /nologo /showIncludes /FC @$rspfile /c {{source}} /Fo{{output}} /Fd\"$pdbname\""
+      depsformat = "msvc"
+      description = "C++ {{output}}"
+      outputs = [
+        "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.obj",
+        # "$object_subdir/{{source_name_part}}.obj",
+      ]
+      rspfile_content = "{{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}}"
+    }    
+
+    tool("alink") {
+      rspfile = "{{output}}.rsp"
+      gyp_win_tool_path = rebase_path("../third_party/externals/gyp/pylib/gyp/win_tool.py")
+      command = "python $gyp_win_tool_path link-wrapper environment.x64 False lib.exe /nologo {{arflags}} /OUT:{{output}} @$rspfile"
+      description = "LIB {{output}}"
+      outputs = [
+        # Ignore {{output_extension}} and always use .lib, there's no reason to
+        # allow targets to override this extension on Windows.
+        #"{{output_dir}}/{{target_output_name}}.lib",
+        "{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
+      ]
+      default_output_extension = ".lib"
+      default_output_dir = "{{target_out_dir}}"
+
+      # The use of inputs_newline is to work around a fixed per-line buffer
+      # size in the linker.
+      rspfile_content = "{{inputs_newline}}"
+    }
+
+    tool("link") {
+      exename = "{{root_out_dir}}/{{target_output_name}}{{output_extension}}"
+      pdbname = "$exename.pdb"
+      rspfile = "$exename.rsp"
+
+      gyp_win_tool_path = rebase_path("../third_party/externals/gyp/pylib/gyp/win_tool.py")
+      command = "python $gyp_win_tool_path link-wrapper environment.x64 False link.exe /nologo /OUT:$exename /PDB:$pdbname @$rspfile"
+
+      default_output_extension = ".exe"
+      default_output_dir = "{{root_out_dir}}"
+      description = "LINK {{output}}"
+      outputs = [
+        #"{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
+        exename,
+      ]
+      #if (symbol_level != 0) {
+      #  outputs += [ pdbname ]
+      #}
+      #runtime_outputs = outputs
+
+      # The use of inputs_newline is to work around a fixed per-line buffer
+      # size in the linker.
+      rspfile_content = "{{inputs_newline}} {{libs}} {{solibs}} {{ldflags}}"
+    }
+
+
+    tool("stamp") {
+      win_stamp_path = rebase_path("win_stamp.py")
+      command = "python $win_stamp_path {{output}}"
+    }
 }
 
-config("release") {
-  cflags = [ "-O3" ]
-  defines = [ "NDEBUG" ]
-}
-
-config("executable") {
-  if (is_mac) {
-    ldflags = [ "-Wl,-rpath,@loader_path/." ]
-  } else if (is_linux) {
-    ldflags = [ "-Wl,-rpath,\$ORIGIN" ]
-  }
-}
-
 toolchain("gcc_like") {
   lib_switch = "-l"
   lib_dir_switch = "-L"
 
   tool("cc") {
     depfile = "{{output}}.d"
     command = "$compiler_prefix $cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_c}} $extra_cflags $extra_cflags_c -c {{source}} -o {{output}}"
     depsformat = "gcc"
     outputs = [
       "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
@@ skipping 60 matching lines @@
   }
 
   tool("stamp") {
     command = "touch {{output}}"
   }
 
   tool("copy") {
     command = "ln -f {{source}} {{output}} 2>/dev/null || (rm -rf {{output}} && cp -af {{source}} {{output}})"
   }
 }