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diff --git a/docs/PNaClDeveloperGuide.rst b/docs/PNaClDeveloperGuide.rst index e807d572f7..5e96f52a62 100644 --- a/docs/PNaClDeveloperGuide.rst +++ b/docs/PNaClDeveloperGuide.rst @@ -9,7 +9,57 @@ PNaCl Developer's Guide Introduction ============ -TODO +PNaCl (pronounced "pinnacle") is a suite of tools for building, testing and +distributing Native Client programs in a platform-independent format. PNaCl +supports client-side translation to the client's native instruction set, thus +enabling support of new instruction sets without recompilation from source. As +PNaCl is layered cleanly on top of current ISA-specific NaCl implementations, +NaCl's small trusted code base, source language neutrality and safety properties +are preserved. + +Nomenclature +------------ + +Throughout this document, we will use the term **Developer** for the person +responsible for the design, implementation and testing of the portable +executable and **User** for the person interacting with it. The **Server** is +the machine from which the PNaCl-based web application is served and the +**Client** is the user's machine, on which the browser runs. The **PNaCl +toolchain** is a set of tools (compiler, linker, client-side translator, etc.) +and supporting libraries that facilitate developing NaCl applications that can +be run by the browser from the web. + +Source language support +======================= + +The currently supported languages are C and C++. The PNaCl toolchain is based on +Clang 3.3, which fully supports C++11 and most of C11. A detailed status of the +language support is available `here <http://clang.llvm.org/cxx_status.html>`_. + +As for the standard libraries, the PNaCl toolchain is currently based on +``libstdc++`` version 4.6.1, and ``newlib`` version 1.20; we plan to upgrade to +the more standard-compliant `libc++ <http://libcxx.llvm.org/>`_ in a future +release. + +Preprocessor definitions +------------------------ + +When compiling C/C++ code, the PNaCl toolchain defines the ``__pnacl__`` macro. +In addition, ``__native_client__`` is defined for compatibility with other NaCl +toolchains. + +High-level development flow +=========================== + +TODO: this needs a nice diagram!! + +The developer write his (or ports an existing) application in C/C++, using the +Pepper APIs to interface with the browser, as usual in NaCl. The PNaCl toolchain +acts similarly to familiar C/C++ development toolchains, with one important +difference: the final output produced by the developer is not a native-code +executable, but a "portable executable" (**pexe**) that the browser can load +and execute from the web. The intermediate products of compilation are portable +object files. Memory Model and Atomics ======================== |