Move LLVM Proposal to doc directory, create index

[jeffbailey]

Summary

The LLVM Libc project is no longer just a proposal and should have
a webpage tracking the status of the project. This changes
puts the pieces into the right place so that the webpage can be
created.

[jeffbailey]

Fix bad copy/past in README.txt from LIBCXX to LIBC

[jeffbailey]

Include missed build pieces for generating HTML from command line.
Two fixes for already checked-in RST files so that they build correctly.

[sivachandra]

Thanks for working on this.

[Ericson2314]

https://lab.llvm.org/buildbot/#/builders/30/builds/16850 this is causing a build failure because llvm/docs/GettingInvolved.rst still links the old proposal.

[jeffbailey]

In D117436#3281435, @Ericson2314 wrote:

https://lab.llvm.org/buildbot/#/builders/30/builds/16850 this is causing a build failure because llvm/docs/GettingInvolved.rst still links the old proposal.

Thanks, and sorry. https://reviews.llvm.org/D118537 is on its way.

libc/.gitignore

+# Sphinx documentation
+docs/_build/
+

libc/CMakeLists.txt

 
 option(LLVM_LIBC_INCLUDE_SCUDO "Include the SCUDO standalone as the allocator for LLVM libc" OFF)
 if(LLVM_LIBC_INCLUDE_SCUDO)
   if (NOT "compiler-rt" IN_LIST LLVM_ENABLE_PROJECTS)
     message(FATAL_ERROR "SCUDO cannot be included without adding compiler-rt to LLVM_ENABLE_PROJECTS")
   endif()
 endif()
 
+option(LIBC_INCLUDE_DOCS "Build the libc documentation." ${LLVM_INCLUDE_DOCS})
+
 include(CMakeParseArguments)
 include(LLVMLibCRules)
 include(LLVMLibCCheckCpuFeatures)
 
 if(EXISTS "${LIBC_SOURCE_DIR}/config/${LIBC_TARGET_OS}/${LIBC_TARGET_ARCHITECTURE}/entrypoints.txt")
   set(entrypoint_file "${LIBC_SOURCE_DIR}/config/${LIBC_TARGET_OS}/${LIBC_TARGET_ARCHITECTURE}/entrypoints.txt")
 elseif(EXISTS "${LIBC_SOURCE_DIR}/config/${LIBC_TARGET_OS}/entrypoints.txt")
   set(entrypoint_file "${LIBC_SOURCE_DIR}/config/${LIBC_TARGET_OS}/entrypoints.txt")

 # of the other directories.
 add_subdirectory(lib)
 if(LLVM_INCLUDE_TESTS)
   add_subdirectory(test)
   add_subdirectory(fuzzing)
 endif()
 
 add_subdirectory(benchmarks)
+
+if (LIBC_INCLUDE_DOCS)
+  add_subdirectory(docs)
+endif()

libc/docs/CMakeLists.txt

+
+if (LLVM_ENABLE_SPHINX)
+include(AddSphinxTarget)
+if (SPHINX_FOUND)
+  if (${SPHINX_OUTPUT_HTML})
+    add_sphinx_target(html libc)
+  endif()
+endif()
+endif()

libc/docs/README.txt

+libc Documentation
+==================
+
+The libc documentation is written using the Sphinx documentation generator. It is
+currently tested with Sphinx 1.1.3.
+
+To build the documents into html configure libc with the following cmake options:
+
+  * -DLLVM_ENABLE_SPHINX=ON
+  * -DLIBC_INCLUDE_DOCS=ON
+
+After configuring libc with these options the make rule `docs-libc-html`
+should be available.

libc/docs/conf.py

+# -*- coding: utf-8 -*-
+#
+# libc documentation build configuration file.
+#
+# This file is execfile()d with the current directory set to its containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+import sys, os
+from datetime import date
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#sys.path.insert(0, os.path.abspath('.'))
+
+# -- General configuration -----------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+#needs_sphinx = '1.0'
+
+# Add any Sphinx extension module names here, as strings. They can be extensions
+# coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
+extensions = ['sphinx.ext.intersphinx', 'sphinx.ext.todo']
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix of source filenames.
+source_suffix = '.rst'
+
+# The encoding of source files.
+#source_encoding = 'utf-8-sig'
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = u'libc'
+copyright = u'2011-%d, LLVM Project' % date.today().year
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The short X.Y version.
+version = '14.0'
+# The full version, including alpha/beta/rc tags.
+release = '14.0'
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#language = None
+
+# There are two options for replacing |today|: either, you set today to some
+# non-false value, then it is used:
+#today = ''
+# Else, today_fmt is used as the format for a strftime call.
+today_fmt = '%Y-%m-%d'
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+exclude_patterns = ['_build', 'Helpers']
+
+# The reST default role (used for this markup: `text`) to use for all documents.
+#default_role = None
+
+# If true, '()' will be appended to :func: etc. cross-reference text.
+#add_function_parentheses = True
+
+# If true, the current module name will be prepended to all description
+# unit titles (such as .. function::).
+#add_module_names = True
+
+# If true, sectionauthor and moduleauthor directives will be shown in the
+# output. They are ignored by default.
+show_authors = True
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'friendly'
+
+# A list of ignored prefixes for module index sorting.
+#modindex_common_prefix = []
+
+
+# -- Options for HTML output ---------------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+html_theme = 'haiku'
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+#html_theme_options = {}
+
+# Add any paths that contain custom themes here, relative to this directory.
+#html_theme_path = []
+
+# The name for this set of Sphinx documents.  If None, it defaults to
+# "<project> v<release> documentation".
+#html_title = None
+
+# A shorter title for the navigation bar.  Default is the same as html_title.
+#html_short_title = None
+
+# The name of an image file (relative to this directory) to place at the top
+# of the sidebar.
+#html_logo = None
+
+# The name of an image file (within the static path) to use as favicon of the
+# docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
+# pixels large.
+#html_favicon = None
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = []
+
+# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
+# using the given strftime format.
+#html_last_updated_fmt = '%b %d, %Y'
+
+# If true, SmartyPants will be used to convert quotes and dashes to
+# typographically correct entities.
+#html_use_smartypants = True
+
+# Custom sidebar templates, maps document names to template names.
+#html_sidebars = {}
+
+# Additional templates that should be rendered to pages, maps page names to
+# template names.
+#html_additional_pages = {}
+
+# If false, no module index is generated.
+#html_domain_indices = True
+
+# If false, no index is generated.
+#html_use_index = True
+
+# If true, the index is split into individual pages for each letter.
+#html_split_index = False
+
+# If true, links to the reST sources are added to the pages.
+#html_show_sourcelink = True
+
+# If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
+#html_show_sphinx = True
+
+# If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
+#html_show_copyright = True
+
+# If true, an OpenSearch description file will be output, and all pages will
+# contain a <link> tag referring to it.  The value of this option must be the
+# base URL from which the finished HTML is served.
+#html_use_opensearch = ''
+
+# This is the file name suffix for HTML files (e.g. ".xhtml").
+#html_file_suffix = None
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'libcxxdoc'
+
+
+# -- Options for LaTeX output --------------------------------------------------
+
+latex_elements = {
+# The paper size ('letterpaper' or 'a4paper').
+#'papersize': 'letterpaper',
+
+# The font size ('10pt', '11pt' or '12pt').
+#'pointsize': '10pt',
+
+# Additional stuff for the LaTeX preamble.
+#'preamble': '',
+}
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title, author, documentclass [howto/manual]).
+latex_documents = [
+  ('contents', 'libcxx.tex', u'libcxx Documentation',
+   u'LLVM project', 'manual'),
+]
+
+# The name of an image file (relative to this directory) to place at the top of
+# the title page.
+#latex_logo = None
+
+# For "manual" documents, if this is true, then toplevel headings are parts,
+# not chapters.
+#latex_use_parts = False
+
+# If true, show page references after internal links.
+#latex_show_pagerefs = False
+
+# If true, show URL addresses after external links.
+#latex_show_urls = False
+
+# Documents to append as an appendix to all manuals.
+#latex_appendices = []
+
+# If false, no module index is generated.
+#latex_domain_indices = True
+
+
+# -- Options for manual page output --------------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    ('contents', 'libc', u'libc Documentation',
+     [u'LLVM project'], 1)
+]
+
+# If true, show URL addresses after external links.
+#man_show_urls = False
+
+
+# -- Options for Texinfo output ------------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+  ('contents', 'libc', u'libc Documentation',
+   u'LLVM project', 'libc', 'One line description of project.',
+   'Miscellaneous'),
+]
+
+# Documents to append as an appendix to all manuals.
+#texinfo_appendices = []
+
+# If false, no module index is generated.
+#texinfo_domain_indices = True
+
+# How to display URL addresses: 'footnote', 'no', or 'inline'.
+#texinfo_show_urls = 'footnote'
+
+
+# FIXME: Define intersphinx configuration.
+intersphinx_mapping = {}
+
+
+# -- Options for extensions ----------------------------------------------------
+
+# Enable this if you want TODOs to show up in the generated documentation.
+todo_include_todos = True

libc/docs/index.rst

-==============================
-"llvm-libc" C Standard Library
-==============================
+=========================
+"libc" C Standard Library
+=========================
 
 .. contents:: Table of Contents
   :depth: 4
   :local:
 
-Introduction
-============
-
-This is a proposal to start *llvm-libc*, an implementation of the
-C standard library targeting C17 and above, as part of the LLVM project.
-llvm-libc will also provide platform specific extensions as relevant.
-For example, on Linux it also provides pthreads, librt and other POSIX
-extension libraries.
-
-Features
-========
+Goals
+=====
 
 llvm-libc will be developed to have a certain minimum set of features:
 
 - C17 and upwards conformant.
 - A modular libc with individual pieces implemented in the "as a
   library" philosophy of the LLVM project.
 - Ability to layer this libc over the system libc if possible and desired
   for a platform.

 1. One cannot mix data structures from llvm-libc with those from the
 system-libc. A translation from one set of data structures to the other should
 happen internal to llvm-libc.
 2. The delegation mechanism has to be implemented over a related set of
 functions. For example, one cannot delegate just the `fopen` function to the
 system-libc. One will have to delegate all `FILE` related functions to the
 system-libc.
 
-Current Status
-==============
-
-llvm-libc development is still in the planning phase.
+Other Interesting Documentation
+===============================
 
-Build Bots
-==========
+.. toctree::
 
-Once the development starts, there will be llvm-libc focused builders added to
-the LLVM BuildBot.
+    build_system
+    clang_tidy_checks
+    entrypoints
+    fuzzing
+    ground_truth_specification
+    header_generation
+    implementation_standard
+    integration_test
+    mechanics_of_public_api
+    redirectors
+    source_layout

libc/docs/redirectors.rst

 the redirector library, which in turn calls the same function from the system
 libc.
 
 Implementation of redirecting entrypoints
 -----------------------------------------
 
 Let us take the ``round`` function from ``math.h`` as an example to see what
 it's implementation looks like when it just redirects to the ``round`` function
-from the system libc.
+from the system libc::
 
-::
     namespace llvm_libc {
 
     double __redirected_round(double);
 
     double LLVM_LIBC_ENTRYPOINT(round)(double x) {
         return __redirected_round(x);
     }
 

libc/docs/source_layout.rst

 
 The ``docs`` directory
 ----------------------
 
 The ``docs`` directory contains design docs and also informative documents like
 this document on source layout.
 
 The ``fuzzing`` directory
-----------------------
+-------------------------
 
 This directory contains fuzzing tests for the various components of llvm-libc. The
 directory structure within this directory mirrors the directory structure of the
 top-level ``libc`` directory itself. For more details, see :doc:`fuzzing`.
 
 The ``include`` directory
 -------------------------