# PDFium ## News As of 2016-05-04, GN is used to generate build files replacing GYP. GYP support will remain until it is disabled in Chromium and then will be removed from PDFium. As of 2016-04-28, the Visual Studio toolchain from depot_tools is used as the default Windows toolchain for Googlers. Please set DEPOT_TOOLS_WIN_TOOLCHAIN=0 if you need to use the system toolchain. See [Windows development subsection](#WinDev) for details. ## Prerequisites Get the chromium depot tools via the instructions at http://www.chromium.org/developers/how-tos/install-depot-tools (this provides the gclient utility needed below). Also install Python, Subversion, and Git and make sure they're in your path. ###<a name="WinDev"></a> Windows development PDFium uses a similar Windows toolchain as Chromium: #### Open source contributors Visual Studio 2015 Update 2 or later is highly recommended. Run `set DEPOT_TOOLS_WIN_TOOLCHAIN=0`, or set that variable in your global environment. Compilation is done through ninja, **not** Visual Studio. #### Google employees Run: `download_from_google_storage --config` and follow the authentication instructions. **Note that you must authenticate with your @google.com credentials**. Enter "0" if asked for a project-id. Once you've done this, the toolchain will be installed automatically for you in [the step](#GenBuild) below. The toolchain will be in `depot_tools\win_toolchain\vs_files\<hash>`, and windbg can be found in `depot_tools\win_toolchain\vs_files\<hash>\win_sdk\Debuggers`. If you want the IDE for debugging and editing, you will need to install it separately, but this is optional and not needed for building PDFium. ## Get the code The name of the top-level directory does not matter. In our examples, we use "repo". This directory must not have been used before by `gclient config` as each directory can only house a single gclient configuration. ``` mkdir repo cd repo gclient config --unmanaged https://pdfium.googlesource.com/pdfium.git gclient sync cd pdfium ``` ##<a name="GenBuild"></a> Generate the build files We use GN to generate the build files and [Ninja](http://martine.github.io/ninja/) (also included with the depot\_tools checkout) to execute the build files. ``` gn gen <directory> ``` If you want to set <directory> to `out/Debug` or `out/Release` you'll need to export `GYP_PDFIUM_NO_ACTION=1` to stop `gclient sync` from executing GYP and overwriting your build files. ###<a name="BuildConfig"></a> Selecting build configuration PDFium may be built either with or without JavaScript support, and with or without XFA forms support. Both of these features are enabled by default. Also note that the XFA feature requires JavaScript. Configuration is done by executing `gn args <directory>` to configure the build. This will launch an editor in which you can set the following arguments. ``` use_goma = true # Googlers only. is_debug = true # Enable debugging features. pdf_use_skia = false # Set true to enable experimental skia backend. pdf_enable_xfa = true # Set false to remove XFA support (implies JS support). pdf_enable_v8 = true # Set false to remove Javascript support. pdf_is_standalone = true # Set for a non-embedded build. clang_use_chrome_plugins = false # Currently must be false. ``` Note, you must set `pdf_is_standalone = true` if you want the sample applications like `pdfium_test` to build. When complete the arguments will be stored in `<directory>/args.gn`. ## Building the code If you used Ninja, you can build the sample program by: `ninja -C <directory>/pdfium_test` You can build the entire product (which includes a few unit tests) by: `ninja -C <directory>`. ## Running the sample program The pdfium\_test program supports reading, parsing, and rasterizing the pages of a .pdf file to .ppm or .png output image files (windows supports two other formats). For example: `<directory>/pdfium_test --ppm path/to/myfile.pdf`. Note that this will write output images to `path/to/myfile.pdf.<n>.ppm`. ## Testing There are currently several test suites that can be run: * pdfium\_unittests * pdfium\_embeddertests * testing/tools/run\_corpus\_tests.py * testing/tools/run\_javascript\_tests.py * testing/tools/run\_pixel\_tests.py It is possible the tests in the `testing` directory can fail due to font differences on the various platforms. These tests are reliable on the bots. If you see failures, it can be a good idea to run the tests on the tip-of-tree checkout to see if the same failures appear. ## Waterfall The current health of the source tree can be found at http://build.chromium.org/p/client.pdfium/console ## Community There are several mailing lists that are setup: * [PDFium](https://groups.google.com/forum/#!forum/pdfium) * [PDFium Reviews](https://groups.google.com/forum/#!forum/pdfium-reviews) * [PDFium Bugs](https://groups.google.com/forum/#!forum/pdfium-bugs) Note, the Reviews and Bugs lists are typically read-only. ## Bugs We use this [bug tracker](https://code.google.com/p/pdfium/issues/list), but for security bugs, please use [Chromium's security bug template] (https://code.google.com/p/chromium/issues/entry?template=Security%20Bug) and add the "Cr-Internals-Plugins-PDF" label. ## Contributing code For contributing code, we will follow [Chromium's process](http://dev.chromium.org/developers/contributing-code) as much as possible. The main exceptions is: 1. Code has to conform to the existing style and not Chromium/Google style.