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.
PDFium uses the same build tool as Chromium:
Please refer to Chromium's Visual Studio set up 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.
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.
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 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.
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
We use GN to generate the build files and Ninja to execute the build files. Both of these are included with the depot_tools checkout.
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.
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.
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.
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 reports for PDFium can be generated in Linux development environments. Details can be found here.
Valgrind and other profiling tools do not work correctly with the standard build
setup that PDFium uses. You will need to add
ro_segment_workaround_for_valgrind=true to args.gn to get symbols to
correctly appear.
The current health of the source tree can be found at https://ci.chromium.org/p/pdfium/g/main/console
There are several mailing lists that are setup:
Note, the Reviews and Bugs lists are typically read-only.
We use this bug tracker, 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.
For contributing code, we will follow Chromium's process as much as possible. The main exceptions are:
- Code has to conform to the existing style and not Chromium/Google style.
- PDFium uses a different tool for code reviews, and credentials for the tool need to be generated before uploading a CL.
- PDFium is currently holding at C++11 compatibility, rejecting features that are only present in C++14 (onto which Chromium is now slowly moving).