# PDFium ## 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. ### Windows development PDFium uses the same build tool as Chromium: #### Open source contributors Please refer to [Chromium's Visual Studio set up](https://chromium.googlesource.com/chromium/src/+/master/docs/windows_build_instructions.md#visual-studio) for requirements and instructions on build environment configuration. Run `set DEPOT_TOOLS_WIN_TOOLCHAIN=0`, or set that variable in your global environment. Compilation is done through ninja, **not** Visual Studio. ### CPU Architectures supported The default architecture for Windows, Linux, and Mac is "`x64`". On Windows, "`x86`" is also supported. GN parameter "`target_cpu = "x86"`" can be used to override the default value. If you specify Android build, the default CPU architecture will be "`arm`". It is expected that there are still some places lurking in the code which will not function properly on big-endian architectures. Bugs and/or patches are welcome, however providing this support is **not** a priority at this time. #### 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 [Generate the build files](#GenBuild) step 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 ``` Additional build dependencies need to be installed by running: ``` ./build/install-build-deps.sh ``` ## Generate the build files We use GN to generate the build files and [Ninja](http://martine.github.io/ninja/) to execute the build files. Both of these are included with the depot\_tools checkout. ### 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. A typical `<directory>` name is `out/Debug`. ``` use_goma = true # Googlers only. Make sure goma is installed and running first. is_debug = true # Enable debugging features. pdf_use_skia = false # Set true to enable experimental skia backend. pdf_use_skia_paths = false # Set true to enable experimental skia backend (paths only). 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. is_component_build = false # Disable component build (must be false) 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`, and GN will automatically use the new arguments to generate build files. Should your files fail to generate, please double-check that you have set use\_sysroot as indicated above. ## Building the code You can build the sample program by running: `ninja -C <directory> pdfium_test` You can build the entire product (which includes a few unit tests) by running: `ninja -C <directory> pdfium_all`. ## 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. ## Code Coverage Code coverage reports for PDFium can be generated in Linux development environments. Details can be found [here](/docs/code-coverage.md). ## 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 are: 1. Code has to conform to the existing style and not Chromium/Google style. 2. PDFium uses a different tool for code reviews, and credentials for the tool need to be generated before uploading a CL. 3. PDFium is currently holding at C++11 compatibility, rejecting features that are only present in C++14 (onto which Chromium is now slowly moving).