.. _sdk-examples-2: Running the SDK Examples ======================== Every Native Client SDK bundle comes with a folder of example applications. Each example demonstrates one or two key Native Client programming concepts. After you've :doc:`downloaded the SDK `, follow the instructions on this page to build and run the examples. Configure the Google Chrome Browser ----------------------------------- #. Your version of Chrome must be equal to or greater than the version of your SDK bundle. For example, if you're developing with the ``pepper_31`` bundle, you must use Google Chrome version 31 or greater. To find out what version of Chrome you're using, type ``about:chrome`` or ``about:version`` in the Chrome address bar. #. For Portable Native Client, no extra Chrome flags are needed as of Chrome version 31. For other Native Client applications, or to **debug** Portable Native Client applications by translating the **pexe** to a **nexe** ahead of time, enable the Native Client flag. Native Client is enabled by default only for applications distributed through the Chrome Web Store. To run Native Client applications that are not distributed through the Chrome Web Store, like the SDK examples, you must specifically enable the Native Client flag in Chrome: * Type ``about:flags`` in the Chrome address bar and scroll down to "Native Client". * If the link below "Native Client" says "Disable", then Native Client is already enabled and you don't need to do anything else. * If the link below "Native Client" says "Enable", click the "Enable" link, scroll down to the bottom of the page, and click the "Relaunch Now" button. All browser windows will restart when you relaunch Chrome. #. Disable the Chrome cache. Chrome caches resources aggressively; when you are building a Native Client application you should disable the cache to make sure that Chrome loads the latest version: * Open Chrome's developer tools by clicking the menu icon |menu-icon| and choosing Tools > Developer tools. * Click the gear icon |gear-icon| in the bottom right corner of the Chrome window. * Under the "General" settings, check the box next to "Disable cache". Build the SDK examples ---------------------- Starting with the ``pepper_24`` bundle, the Makefile scripts for the SDK examples build multiple versions of the examples using all three SDK toolchains (newlib, glibc, and PNaCl) and in both release and debug configurations. (Note that some examples build only with the particular toolchains). To build all the examples, go to the examples directory in a specific SDK bundle and run ``make``:: $ cd pepper_31/examples $ make make -C api all make[1]: Entering directory `pepper_31/examples/api' make -C audio all make[2]: Entering directory `pepper_31/examples/api/audio' CXX newlib/Debug/audio_x86_32.o LINK newlib/Debug/audio_x86_32.nexe CXX newlib/Debug/audio_x86_64.o LINK newlib/Debug/audio_x86_64.nexe CXX newlib/Debug/audio_arm.o LINK newlib/Debug/audio_arm.nexe CREATE_NMF newlib/Debug/audio.nmf make[2]: Leaving directory `pepper_31/examples/api/audio' make -C url_loader all make[2]: Entering directory `pepper_31/examples/api/url_loader' CXX newlib/Debug/url_loader_x86_32.o ... Calling ``make`` from inside a particular example's directory will build only that example:: $ cd pepper_31/examples/api/core $ make CXX newlib/Debug/core_x86_32.o LINK newlib/Debug/core_x86_32.nexe CXX newlib/Debug/core_x86_64.o LINK newlib/Debug/core_x86_64.nexe CXX newlib/Debug/core_arm.o LINK newlib/Debug/core_arm.nexe CREATE_NMF newlib/Debug/core.nmf You can call ``make`` with the ``TOOLCHAIN`` and ``CONFIG`` parameters to override the defaults:: $ make TOOLCHAIN=pnacl CONFIG=Release CXX pnacl/Release/core_pnacl.o LINK pnacl/Release/core.bc FINALIZE pnacl/Release/core.pexe CREATE_NMF pnacl/Release/core.nmf You can also set ``TOOLCHAIN`` to "all" to build one or more examples with all available toolchains:: $ make TOOLCHAIN=all make TOOLCHAIN=newlib make[1]: Entering directory `pepper_31/examples/api/core' CXX newlib/Debug/core_x86_32.o LINK newlib/Debug/core_x86_32.nexe CXX newlib/Debug/core_x86_64.o LINK newlib/Debug/core_x86_64.nexe CXX newlib/Debug/core_arm.o LINK newlib/Debug/core_arm.nexe CREATE_NMF newlib/Debug/core.nmf make[1]: Leaving directory `pepper_31/examples/api/core' make TOOLCHAIN=glibc make[1]: Entering directory `pepper_31/examples/api/core' CXX glibc/Debug/core_x86_32.o LINK glibc/Debug/core_x86_32.nexe CXX glibc/Debug/core_x86_64.o LINK glibc/Debug/core_x86_64.nexe CREATE_NMF glibc/Debug/core.nmf make[1]: Leaving directory `pepper_31/examples/api/core' make TOOLCHAIN=pnacl make[1]: Entering directory `pepper_31/examples/api/core' CXX pnacl/Debug/core.o LINK pnacl/Debug/core_unstripped.bc FINALIZE pnacl/Debug/core_unstripped.pexe CREATE_NMF pnacl/Debug/core.nmf make[1]: Leaving directory `pepper_31/examples/api/core' make TOOLCHAIN=linux make[1]: Entering directory `pepper_31/examples/api/core' CXX linux/Debug/core.o LINK linux/Debug/core.so make[1]: Leaving directory `pepper_31/examples/api/core' After running ``make``, each example directory will contain one or more of the following subdirectories: * a ``newlib`` directory with subdirectories ``Debug`` and ``Release``; * a ``glibc`` directory with subdirectories ``Debug`` and ``Release``; * a ``pnacl`` directory with subdirectories ``Debug`` and ``Release``; For the newlib and glibc toolchains the Debug and Release subdirectories contain .nexe files for all target architectures. For the PNaCl toolchain they contain a single .pexe file. PNaCl debug also produces pre-translated .nexe files, for ease of debugging. All Debug and Release directories contain a manifest (.nmf) file that references the associated .nexe or .pexe files. For information about Native Client manifest files, see the :doc:`Technical Overview <../overview>`. For details on how to use ``make``, see the `GNU 'make' Manual `_. For details on how to use the SDK toolchain itself, see :doc:`Building Native Client Modules <../devguide/devcycle/building>`. .. _running_the_sdk_examples: Run the SDK examples -------------------- To run the SDK examples, you can use the ``make run`` command:: $ cd pepper_31/examples/api/core $ make run This will launch a local HTTP server which will serve the data for the example. It then launches Chrome with the address of this server, usually ``http://localhost:5103``. After you close Chrome, the local HTTP server is automatically shutdown. This command will try to find an executable named ``google-chrome`` in your ``PATH`` environment variable. If it can't, you'll get an error message like this:: pepper_31/tools/common.mk:415: No valid Chrome found at CHROME_PATH= pepper_31/tools/common.mk:415: *** Set CHROME_PATH via an environment variable, or command-line.. Stop. Set the CHROME_PATH environment variable to the location of your Chrome executable. * On Windows: The default install location of Chrome is ``C:\Program Files (x86)\Google\Chrome\Application\chrome.exe`` for Chrome stable and ``C:\Users\\AppData\Local\Google\Chrome SxS\Application\chrome.exe`` for Chrome Canary; try looking in those directories first:: > set CHROME_PATH= * On Linux:: $ export CHROME_PATH= * On Mac: The default install location of Chrome is ``/Applications/Google Chrome.app/Contents/MacOS/Google Chrome`` for Chrome Stable and ``Applications/Google Chrome Canary.app/Contents/MacOS/Google Chrome Canary`` for Chrome Canary. Note that you have to reference the executable inside the application bundle, not the top-level ``.app`` directory:: $ export CHROME_PATH= You can run via a different toolchain or configuration by using the ``TOOLCHAIN`` and ``CONFIG`` parameters to make:: $ make run TOOLCHAIN=pnacl CONFIG=Debug .. _run_sdk_examples_as_packaged: Run the SDK examples as packaged apps ------------------------------------- Each example can also be launched as a packaged app. For more information about using Native Client for packaged apps, see :ref:`Packaged application `. For general information about packaged apps, see the `Chrome apps documentation `_. Some Pepper features, such as TCP/UDP socket access, are only allowed in packaged apps. The examples that use these features must be run as packaged apps, by using the ``make run_package`` command:: $ make run_package You can use ``TOOLCHAIN`` and ``CONFIG`` parameters as above to run with a different toolchain or configuration. .. _debugging_the_sdk_examples: Debugging the SDK examples -------------------------- The NaCl SDK uses `GDB `_ to debug Native Client code. The SDK includes a prebuilt version of GDB that is compatible with NaCl code. To use it, run the ``make debug`` command from an example directory:: $ make debug This will launch Chrome with the ``--enable-nacl-debug`` flag set. This flag will cause Chrome to pause when a NaCl module is first loaded, waiting for a connection from gdb. The ``make debug`` command also simultaneously launches GDB and loads the symbols for that NEXE. To connect GDB to Chrome, in the GDB console, type:: (gdb) target remote :4014 This tells GDB to connect to a TCP port on ``localhost:4014``--the port that Chrome is listening on. GDB will respond:: Remote debugging using :4014 0x000000000fa00080 in ?? () At this point, you can use the standard GDB commands to debug your NaCl module. The most common commands you will use to debug are ``continue``, ``step``, ``next``, ``break`` and ``backtrace``. See :doc:`Debugging <../devguide/devcycle/debugging>` for more information about debugging a Native Client application. .. |menu-icon| image:: /images/menu-icon.png .. |gear-icon| image:: /images/gear-icon.png