|  | # 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). |