Dylan McKay ab1efa5f6d Add default address space for functions to the data layout (1/3)
Summary:
This adds initial support for letting targets specify which address
spaces their functions should reside in by default.

If a function is created by a frontend, it will get the default address space specified in the DataLayout, unless the frontend explicitly uses a more general `llvm::Function` constructor. Function address spaces will become a part of the bitcode and textual IR forms, as we do not have access to a data layout whilst parsing LL.

It will be possible to write IR that explicitly has `addrspace(n)` on a function. In this case, the function will reside in the specified space, ignoring the default in the DL.

This is the first step towards placing functions into the correct
address space for Harvard architectures.

Full patchset
* Add program address space to data layout D37052
* Require address space to be specified when creating functions D37054
* [clang] Require address space to be specified when creating functions D37057

Reviewers: pcc, arsenm, kparzysz, hfinkel, theraven

Reviewed By: theraven

Subscribers: arichardson, simoncook, rengolin, wdng, uabelho, bjope, asb, llvm-commits

Differential Revision: https://reviews.llvm.org/D37052

llvm-svn: 325479
2018-02-19 09:56:22 +00:00
..
2018-01-12 21:42:39 +00:00
2018-01-05 00:24:55 +00:00
2018-01-03 14:52:54 +00:00
2018-01-04 17:12:21 +00:00
2017-02-07 20:36:03 +00:00
2018-01-04 17:12:21 +00:00
2017-08-18 15:35:53 +00:00
2017-04-03 18:21:50 +00:00
2017-06-24 20:13:32 +00:00
2017-09-22 21:10:37 +00:00

LLVM Documentation
==================

LLVM's documentation is written in reStructuredText, a lightweight
plaintext markup language (file extension `.rst`). While the
reStructuredText documentation should be quite readable in source form, it
is mostly meant to be processed by the Sphinx documentation generation
system to create HTML pages which are hosted on <http://llvm.org/docs/> and
updated after every commit. Manpage output is also supported, see below.

If you instead would like to generate and view the HTML locally, install
Sphinx <http://sphinx-doc.org/> and then do:

    cd <build-dir>
    cmake -DLLVM_ENABLE_SPHINX=true -DSPHINX_OUTPUT_HTML=true <src-dir>
    make -j3 docs-llvm-html
    $BROWSER <build-dir>/docs//html/index.html

The mapping between reStructuredText files and generated documentation is
`docs/Foo.rst` <-> `<build-dir>/docs//html/Foo.html` <-> `http://llvm.org/docs/Foo.html`.

If you are interested in writing new documentation, you will want to read
`SphinxQuickstartTemplate.rst` which will get you writing documentation
very fast and includes examples of the most important reStructuredText
markup syntax.

Manpage Output
===============

Building the manpages is similar to building the HTML documentation. The
primary difference is to use the `man` makefile target, instead of the
default (which is `html`). Sphinx then produces the man pages in the
directory `<build-dir>/docs/man/`.

    cd <build-dir>
    cmake -DLLVM_ENABLE_SPHINX=true -DSPHINX_OUTPUT_MAN=true <src-dir>
    make -j3 docs-llvm-man
    man -l >build-dir>/docs/man/FileCheck.1

The correspondence between .rst files and man pages is
`docs/CommandGuide/Foo.rst` <-> `<build-dir>/docs//man/Foo.1`.
These .rst files are also included during HTML generation so they are also
viewable online (as noted above) at e.g.
`http://llvm.org/docs/CommandGuide/Foo.html`.

Checking links
==============

The reachability of external links in the documentation can be checked by
running:

    cd docs/
    make -f Makefile.sphinx linkcheck

Doxygen page Output
==============

Install doxygen <http://www.stack.nl/~dimitri/doxygen/download.html> and dot2tex <https://dot2tex.readthedocs.io/en/latest>.

    cd <build-dir>
    cmake -DLLVM_ENABLE_DOXYGEN=On <llvm-top-src-dir>
    make doxygen-llvm # for LLVM docs
    make doxygen-clang # for clang docs

It will generate html in
    
    <build-dir>/docs/doxygen/html # for LLVM docs
    <build-dir>/tools/clang/docs/doxygen/html # for clang docs