[SYCL] Add CodingGuidelines.rst for libsycl

libsycl/docs/CodingGuidelines.rst

@@ -0,0 +1,39 @@
+========================
+Libsycl Coding Standards
+========================
+
+.. contents::
+   :local:
+
+Introduction
+============
+
+The ``libsycl`` project follows the
+`LLVM Coding Standards <https://llvm.org/docs/CodingStandards.html>`_ with
+exceptions as described in this document.
+
+Naming
+------
+
+Names of Macros, Types, Functions, Variables, and Enumerators
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Entities specified by the SYCL specification are named as required by the SYCL
+specification. Names of all other entities follow the guidance in the LLVM
+Coding Standards.
+
+Names of Files and Directories
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* **Directory Names** should be in snake case (e.g. ``test_e2e``) except in
+  cases where LLVM project wide conventions are used. For example, LIT tests
+  often use an ``Inputs`` directory to hold files that are used by tests but
+  that should be excluded from test discovery.
+
+* **File Names in snake case** should be used for all C++ implementation files.
+  For example files in directories ``include``, ``src``, ``test``, ``utils``,
+  and ``tools`` should be named in snake case.
+
+* **File Names in camel case** should be used for most other files. For example
+  files in directories ``cmake/modules`` and ``docs`` should be named in camel
+  case.