llvm-6502/docs
Sanjoy Das 5ff5907996 [IR] Introduce a dereferenceable_or_null(N) attribute.
Summary:
If a pointer is marked as dereferenceable_or_null(N), LLVM assumes it
is either `null` or `dereferenceable(N)` or both.  This change only
introduces the attribute and adds a token test case for the `llvm-as`
/ `llvm-dis`.  It does not hook up other parts of the optimizer to
actually exploit the attribute -- those changes will come later.

For pointers in address space 0, `dereferenceable(N)` is now exactly
equivalent to `dereferenceable_or_null(N)` && `nonnull`.  For other
address spaces, `dereferenceable(N)` is potentially weaker than
`dereferenceable_or_null(N)` && `nonnull` (since we could have a null
`dereferenceable(N)` pointer).

The motivating case for this change is Java (and other managed
languages), where pointers are either `null` or dereferenceable up to
some usually known-at-compile-time constant offset.

Reviewers: rafael, hfinkel

Reviewed By: hfinkel

Subscribers: nicholas, llvm-commits

Differential Revision: http://reviews.llvm.org/D8650

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235132 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 20:29:50 +00:00
..
_static
_templates
_themes/llvm-theme
CommandGuide docs: Update llvm-cov docs for the -use-color flag 2015-03-19 18:22:46 +00:00
Frontend Add a few more performance tips 2015-03-05 05:55:55 +00:00
HistoricalNotes
TableGen Remove neverHasSideEffects support from TableGen CodeGenInstruction. Everyone should use hasSideEffects now. 2014-11-26 04:11:14 +00:00
tutorial Correct 'teh' and other typos / repeated words. 2015-04-14 20:52:58 +00:00
AliasAnalysis.rst Update some AliasAnalysis pass docs for getAdjustedAnalysisPointer. 2014-05-22 19:38:25 +00:00
ARM-BE-bitcastfail.png [ARM64-BE] Add sphinx documentation for the ARM64 NEON implementation. 2014-05-12 15:13:39 +00:00
ARM-BE-bitcastsuccess.png [ARM64-BE] Add sphinx documentation for the ARM64 NEON implementation. 2014-05-12 15:13:39 +00:00
ARM-BE-ld1.png [ARM64-BE] Add sphinx documentation for the ARM64 NEON implementation. 2014-05-12 15:13:39 +00:00
ARM-BE-ldr.png [ARM64-BE] Add sphinx documentation for the ARM64 NEON implementation. 2014-05-12 15:13:39 +00:00
Atomics.rst [sphinx cleanup] Fix unexpected indentation warning introduced by r218937 2014-10-03 12:28:48 +00:00
BigEndianNEON.rst Fix typos 2014-05-15 01:52:21 +00:00
BitCodeFormat.rst Misc documentation/comment fixes. 2015-02-04 00:42:45 +00:00
BitSets.rst LowerBitSets: Introduce global layout builder. 2015-02-24 23:17:02 +00:00
BlockFrequencyTerminology.rst Fix typos 2014-05-15 01:52:21 +00:00
BranchWeightMetadata.rst
Bugpoint.rst Correct 'teh' and other typos / repeated words. 2015-04-14 20:52:58 +00:00
BuildingLLVMWithAutotools.rst A few minor updates based on feedback from Justin and a few things I thought were missing. 2015-03-14 21:20:32 +00:00
CMake.rst [ADT][CMake][AutoConf] Fail-fast iterators for DenseMap 2015-03-26 19:25:01 +00:00
CMakeLists.txt [OCaml] Move Llvm.clone_module to its own Llvm_transform_utils module. 2014-12-01 19:50:39 +00:00
CodeGenerator.rst Fix grammar in documentation. 2015-02-19 18:46:25 +00:00
CodingStandards.rst CodingStyle: Allow delegating ctors 2015-03-06 13:46:50 +00:00
CommandLine.rst Update the example of using a command-line option custom parser to 2014-10-13 21:11:22 +00:00
CompilerWriterInfo.rst [docs] Add link to the MIPS 64-bit ELF object file specification 2015-01-25 16:20:30 +00:00
conf.py Trunk is now 3.7.0svn 2015-01-14 17:38:03 +00:00
CoverageMappingFormat.rst Docs: add documentation for the coverage mapping format. 2014-08-19 17:05:58 +00:00
DebuggingJITedCode.rst
DeveloperPolicy.rst Adding commit msg guidelines to dev policy 2015-03-15 21:15:48 +00:00
doxygen.cfg.in [docs] Update the doxygen configuration file. 2015-03-12 17:26:27 +00:00
doxygen.intro
Dummy.html
ExceptionHandling.rst [WinEH] Sink UnwindHelp completely out of IR 2015-04-03 22:32:26 +00:00
ExtendedIntegerResults.txt
ExtendingLLVM.rst [docs] Update outdated ExtendingLLVM.rst 2015-04-13 16:04:17 +00:00
Extensions.rst Use a comma after the unique keyword. 2015-04-06 16:34:41 +00:00
FAQ.rst
GarbageCollection.rst [GC Docs] Update LangRef to link to Statepoint docs 2015-02-25 23:45:20 +00:00
gcc-loops.png
GetElementPtr.rst Update LangRef for getelementptr explicit type changes 2015-03-04 22:02:58 +00:00
GettingStarted.rst A few minor updates based on feedback from Justin and a few things I thought were missing. 2015-03-14 21:20:32 +00:00
GettingStartedVS.rst Update the docs to require at least MSVC 2013. 2015-02-15 19:34:17 +00:00
GoldPlugin.rst Docs: give binutils/gold instructions for CMake too. 2014-11-04 02:16:03 +00:00
HowToAddABuilder.rst
HowToBuildOnARM.rst
HowToCrossCompileLLVM.rst
HowToReleaseLLVM.rst docs: Update relaease documents to include the patch number in the RELEASE tags 2014-07-21 14:28:31 +00:00
HowToSetUpLLVMStyleRTTI.rst [docs][LLVM-style RTTI] Add a mention of multiple inheritance. 2015-02-07 01:16:26 +00:00
HowToSubmitABug.rst Delete -std-compile-opts. 2014-10-16 20:00:02 +00:00
HowToUseAttributes.rst
HowToUseInstrMappings.rst
InAlloca.rst
index.rst Move lib/Fuzzer docs from a README.txt to a proper .rst file. 2015-03-30 23:05:30 +00:00
LangRef.rst [IR] Introduce a dereferenceable_or_null(N) attribute. 2015-04-16 20:29:50 +00:00
Lexicon.rst [docs] Document what "NFC" means in a commit message. 2014-09-06 00:19:16 +00:00
LibFuzzer.rst [lib/Fuzzer] Section: How good is my fuzzer? 2015-04-10 06:32:29 +00:00
LinkTimeOptimization.rst Fix a typo in the documentation of LTO 2014-12-03 07:32:36 +00:00
linpack-pc.png
LLVMBuild.rst
LLVMBuild.txt
make.bat
Makefile [docs] Update the doxygen configuration file. 2015-03-12 17:26:27 +00:00
Makefile.sphinx Revert "Treat warnings in Sphinx as errors. The reasons for doing this are..." 2014-07-22 18:09:17 +00:00
MakefileGuide.rst
MarkedUpDisassembly.rst undo test commit (whitespace only) 2014-06-30 08:09:35 +00:00
MCJIT-creation.png
MCJIT-dyld-load.png
MCJIT-engine-builder.png
MCJIT-load-object.png
MCJIT-load.png
MCJIT-resolve-relocations.png
MCJITDesignAndImplementation.rst Minor typo. 2014-09-05 04:56:43 +00:00
MergeFunctions.rst Inspired by r231891, use gender neutral pronouns in the places I've 2015-03-11 00:15:44 +00:00
NVPTXUsage.rst
Packaging.rst
Passes.rst Remove the preverify pass from the documentation now that it has been removed 2015-01-30 20:51:09 +00:00
Phabricator.rst [docs] add cross-reference 2015-03-31 15:07:53 +00:00
ProgrammersManual.rst Editorial changes in the programmers manual. 2015-04-16 17:01:23 +00:00
Projects.rst
R600Usage.rst R600/SI: Initial support for assembler and inline assembly 2015-04-08 01:09:26 +00:00
re_format.7
README.txt [docs] Add a note to docs/README.txt 2014-04-22 21:47:53 +00:00
ReleaseNotes.rst Update 3.7 Release Note mentionning the non-optionality of the DataLayout 2015-03-18 22:01:44 +00:00
ReleaseProcess.rst
SegmentedStacks.rst
SourceLevelDebugging.rst docs: Update LangRef and SourceLevelDebugging 2015-03-17 23:41:05 +00:00
SphinxQuickstartTemplate.rst
StackMaps.rst [PowerPC] Adjust PatchPoints for ppc64le 2015-01-16 04:40:58 +00:00
Statepoints.rst [GC docs] Add example IR, assembly, and stackmaps to Statepoint documentation 2015-02-26 01:18:21 +00:00
SystemLibrary.rst
TableGenFundamentals.rst
TestingGuide.rst Require python 2.7. 2014-12-12 15:29:31 +00:00
TestSuiteMakefileGuide.rst
Vectorizers.rst Correct 'teh' and other typos / repeated words. 2015-04-14 20:52:58 +00:00
WritingAnLLVMBackend.rst configure.ac lives in autoconf/, not autotools/ 2014-11-10 22:36:04 +00:00
WritingAnLLVMPass.rst [PM] Split the LoopInfo object apart from the legacy pass, creating 2015-01-17 14:16:18 +00:00
yaml2obj.rst
YamlIO.rst Correct 'teh' and other typos / repeated words. 2015-04-14 20:52:58 +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 docs/
    make -f Makefile.sphinx
    $BROWSER _build/html/index.html

The mapping between reStructuredText files and generated documentation is
`docs/Foo.rst` <-> `_build/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/man/`.

    cd docs/
    make -f Makefile.sphinx man
    man -l _build/man/FileCheck.1

The correspondence between .rst files and man pages is
`docs/CommandGuide/Foo.rst` <-> `_build/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 reachibility of external links in the documentation can be checked by
running:

    cd docs/
    make -f Makefile.sphinx linkcheck