WinCairo port is a WebKit port for Windows, which is fully OpenSouce and redistributable unlike AppleWin port. It is using Cairo for the graphics backend, libcurl for the network backend. It supports only 64 bit.

Installing Development Tools

You need CMake, Perl, Python 2.7, Ruby, gperf and Visual Studio 2019 to build WinCairo port.

You can follow ​AppleWin port's instructions to install the necessary developer tools, and check out the WebKit code.

The easiest way to install some tools is using ​Chocolatey,

choco install cmake ActivePerl python2 ruby git svn patch diffutils gperf -y

Building WinCairo

In the top source directory, use

perl Tools/Scripts/build-webkit --wincairo --release

to start the build. Ensure you don't have GCC in your PATH, otherwise CMake is going to use GCC and builds will fail.

build-webkit automatically downloads the latest WebKitRequirements from GitHub. It checks the latest WebKitRequirements every time you invoke. I'd like to recommend to use --skip-library-update for incremental build to speed up.

python Tools\Scripts\update-webkit-wincairo-libs.py
perl Tools\Scripts\build-webkit --wincairo --release --skip-library-update

Building from within Visual Studio

Start "x64 Native Tools Command Prompt for VS 2019".

perl Tools/Scripts/build-webkit --wincairo --release --no-ninja --generate-project-only

Some environment variables should be propagated to Visual Studio.

set WEBKIT_LIBRARIES=%cd%\WebKitLibraries\win
set WEBKIT_OUTPUTDIR=%cd%\WebKitBuild

If you are behind http proxy, you need more environment variables for libcurl.

set http_proxy=http://proxy.example.com:8080/
set https_proxy=%http_proxy%
set no_proxy=localhost,127.0.0.1

Open the generated solution file by devenv.

devenv WebKitBuild\Release\WebKit.sln

Build "MiniBrowser" project.

Debugging WinCairo

• Debugging With Visual Studio.
• ​Logging in WebKit

Required Libraries

You will get required libraries downloaded automatically when you perform a build-webkit --wincairo. The source code is hosted in: ​https://github.com/WebKitForWindows/WebKitRequirements

Running the tests

XAMPP should be installed in the default install path (c:\xampp). Currently, I'm observing crashes in php7ts.dll of httpd.exe of XAMPP v7.4.16. So install v7.3.

choco install -y XAMPP-73

pip install pywin32
gem install webrick

If Apache service is running, stop it by using Services of Control Panel.

Some extensions need to be registered as CGI. Modify the following commands for your Perl an Python paths, and run them as administrator.

reg add HKEY_CLASSES_ROOT\.pl\Shell\ExecCGI\Command /ve /d "c:\xampp\perl\bin\perl.exe -T"
reg add HKEY_CLASSES_ROOT\.cgi\Shell\ExecCGI\Command /ve /d "c:\xampp\perl\bin\perl.exe -T"
reg add HKEY_CLASSES_ROOT\.py\Shell\ExecCGI\Command /ve /d "c:\Python39\python.exe -X utf8"

You need openssl.exe in your PATH to run wpt server. XAMPP contains openssl.exe in C:\xampp\apache\bin directory. Append the directory to your PATH.

Open a command prompt as administrator because http tests need to run Apache service. Set some environment variables.

set WEBKIT_LIBRARIES=%cd%\WebKitLibraries\win
set WEBKIT_OUTPUTDIR=%cd%\WebKitBuild
set WEBKIT_TESTFONTS=%cd%\Tools\WebKitTestRunner\fonts
set DUMPRENDERTREE_TEMP=%TEMP%

Invoke run-webkit-tests.

# for WebKit1
python Tools/Scripts/run-webkit-tests --release --wincairo -1
# for WebKit2
python Tools/Scripts/run-webkit-tests --release --wincairo

You can use Docker to run LayoutTests by mounting the host directory.

docker run -it --rm --cpu-count=8 --memory=16g -v %cd%:c:\repo -w c:\repo webkitdev/msbuild

If you are using Japanese Windows, some layout tests fails due to form control size differences. GetStockObject(DEFAULT_GUI_FONT) returns MS UI Gothic on it. Remove GUIFont.Facename of HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\GRE_Initialize. And, replace MS UI Gothic with Microsoft Sans Serif in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontSubstitutes\MS Shell Dlg.

If http tests fail as flaky failures due to the socket count limit, increase the user port range. See ​Bug 224523

netsh int ipv4 set dynamicport tcp start=1025 num=64511

Download build artifacts from Buildbot

• Go to ​WinCairo-64-bit-WKL-Release-Build Buildbot builder page.
• Click any "Build #" which is green.
• Click "> stdio" of "transfer-to-s3".
• You can find "S3 URL" in the console log.
• Download the zip.
• Download the corresponding release of WinCairoRequirements. ​https://github.com/WebKitForWindows/WinCairoRequirements/releases

• Unpack them, copy all DLL of WinCairoRequirements to the directory of MiniBrowser.exe
• Install ​vc_redist.x64.exe of Microsoft Visual C++ Redistributable for Visual Studio 2019

Compile WinCairo with Clang

clang-cl has a problem for /MP support. ​https://reviews.llvm.org/D52193 It's recommended to use Ninja with clang-cl. Install clang-cl and Ninja.

choco install llvm ninja -y

Open Visual Studio Command Prompt, and invoke the following commands.

set CC=clang-cl
set CXX=clang-cl
perl Tools\Scripts\build-webkit --release --wincairo --ninja

clang-cl builds are experimental, see ​Bug 171618 for the current status.