llvm-project/llvm/docs
Manoj Gupta 77eeac3d9e llvm: Add support for "-fno-delete-null-pointer-checks"
Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.

More details : https://lkml.org/lkml/2018/4/4/601

GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.

-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.

This feature is implemented in LLVM IR in this CL as the function attribute
"null-pointer-is-valid"="true" in IR (Under review at D47894).
The CL updates several passes that assumed null pointer dereferencing is
undefined to not optimize when the "null-pointer-is-valid"="true"
attribute is present.

Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv

Reviewed By: efriedma, george.burgess.iv

Subscribers: eraman, haicheng, george.burgess.iv, drinkcat, theraven, reames, sanjoy, xbolva00, llvm-commits

Differential Revision: https://reviews.llvm.org/D47895

llvm-svn: 336613
2018-07-09 22:27:23 +00:00
..
CommandGuide nm: Add -no-weak flag for hiding weak symbols 2018-07-02 17:24:37 +00:00
Frontend
HistoricalNotes
PDB Update MSF File Documentation. 2018-01-12 21:42:39 +00:00
Proposals remove unreferenced footnotes 2018-01-05 00:24:55 +00:00
TableGen TableGen/SearchableTables: Support more generic enums and tables 2018-06-21 13:36:22 +00:00
_ocamldoc
_static
_templates
_themes/llvm-theme
tutorial [docs] Fix a typo in KaleidoscopeJIT tutorial 2018-05-08 18:43:27 +00:00
AMDGPUAsmGFX7.rst [AMDGPU][MC][DOC] Updated AMD GPU assembler description 2018-03-12 15:55:08 +00:00
AMDGPUAsmGFX8.rst [AMDGPU][MC][DOC] Updated AMD GPU assembler description 2018-03-12 15:55:08 +00:00
AMDGPUAsmGFX9.rst [AMDGPU][MC][DOC] Updated AMD GPU assembler description 2018-03-12 15:55:08 +00:00
AMDGPUOperandSyntax.rst [AMDGPU][MC][DOC] Updated AMD GPU assembler description 2018-03-12 15:55:08 +00:00
AMDGPUUsage.rst AMDHSA: Put old assembler docs back 2018-06-22 19:23:18 +00:00
ARM-BE-bitcastfail.png
ARM-BE-bitcastsuccess.png
ARM-BE-ld1.png
ARM-BE-ldr.png
AdvancedBuilds.rst [NFC] Remove apostrophe to use 'it' in the possessive form. 2018-01-26 18:43:57 +00:00
AliasAnalysis.rst [doc] Removed obsolete -count-aa from AliasAnalysis documentation 2018-04-23 13:45:28 +00:00
Atomics.rst
Benchmarking.rst Add some tips on benchmarking. 2017-05-24 16:39:12 +00:00
BigEndianNEON.rst
BitCodeFormat.rst Add the ShadowCallStack attribute 2018-04-03 20:10:40 +00:00
BlockFrequencyTerminology.rst
BranchWeightMetadata.rst [Doc] Document prof metadata in LangRef 2017-06-15 15:57:12 +00:00
Bugpoint.rst Rename DEBUG macro to LLVM_DEBUG. 2018-05-14 12:53:11 +00:00
CFIVerify.rst fix path to llvm-cfi-verify unittests in docs 2018-05-09 01:15:06 +00:00
CMake.rst Remove LLVM_INSTALL_CCTOOLS_SYMLINKS 2018-04-24 15:41:02 +00:00
CMakeLists.txt [dsymutil][doc] Improve wording in manpage and rename file. 2017-11-02 18:44:54 +00:00
CMakePrimer.rst [docs] In the CMake primer, correct the description of the ARGV/ARGN variables. 2017-08-24 05:38:39 +00:00
CodeGenerator.rst [NFC] fix trivial typos in documents 2018-06-15 05:10:09 +00:00
CodeOfConduct.rst
CodingStandards.rst [NFC] update coding standard links to HTTPS 2018-05-18 16:44:13 +00:00
CommandLine.rst Rename DEBUG macro to LLVM_DEBUG. 2018-05-14 12:53:11 +00:00
CompileCudaWithLLVM.rst [Docs] Update docs to indicate that CUDA compilation is supported on Windows. 2017-01-05 16:54:28 +00:00
CompilerWriterInfo.rst [docs] Update CompilerWriterInfo.rst for MIPS 2018-06-14 15:16:37 +00:00
Contributing.rst [Docs] Add LLVM for Grad Students to Contributing page. 2018-03-02 14:35:02 +00:00
Coroutines.rst [coroutines] Add support for llvm.coro.noop intrinsics 2018-04-02 16:55:12 +00:00
CoverageMappingFormat.rst [Coverage] Use gap regions to select better line exec counts 2017-09-18 23:37:28 +00:00
DebuggingJITedCode.rst
DeveloperPolicy.rst Fixed broken links in docs. 2017-09-22 21:10:37 +00:00
Docker.rst Migrate dockerfiles to use multi-stage builds. 2018-03-26 15:12:30 +00:00
ExceptionHandling.rst [NFC] fix trivial typos in documents and comments 2018-04-12 05:53:20 +00:00
ExtendedIntegerResults.txt
ExtendingLLVM.rst
Extensions.rst docs: document CodeView directives 2018-06-19 16:47:31 +00:00
FAQ.rst
FaultMaps.rst Fix the docs build 2017-02-07 20:36:03 +00:00
FuzzingLLVM.rst [llvm-opt-fuzzer] Introduce llvm-opt-fuzzer for fuzzing optimization passes 2017-11-10 12:19:08 +00:00
GarbageCollection.rst Remove @brief commands from doxygen comments, too. 2018-05-01 16:10:38 +00:00
GetElementPtr.rst [docs] Update code block for compatibility with Sphinx 1.5.1 2017-11-06 11:47:24 +00:00
GettingStarted.rst Document the git config for Windows to do line-endings correctly. 2018-06-27 19:58:28 +00:00
GettingStartedVS.rst [MC] Fix regression tests on Windows when git “core.autocrlf” is set to true. 2017-11-17 21:59:43 +00:00
GlobalISel.rst [globalisel] Add very brief docs summarizing the ISel part of the LLVMDev tutorial. 2017-10-23 17:18:44 +00:00
GoldPlugin.rst [docs] As of binutils 2.21.51.0.2, ld.bfd supports plugins too, represent this in docs 2017-06-23 13:54:10 +00:00
HowToAddABuilder.rst Added more info on silent master to the doc. 2017-07-05 20:45:44 +00:00
HowToBuildOnARM.rst
HowToCrossCompileBuiltinsOnArm.rst [docs][ARM] Add HowTo for cross compiling and testing compiler-rt builtins 2017-11-07 09:40:05 +00:00
HowToCrossCompileLLVM.rst
HowToReleaseLLVM.rst docs: Fix formatting in HowToReleaseLLVM 2017-09-19 03:27:26 +00:00
HowToSetUpLLVMStyleRTTI.rst
HowToSubmitABug.rst [docs] Fix mention of GCC frontend 2018-01-15 17:11:22 +00:00
HowToUseAttributes.rst Fix RST docs AttributeList heading underline 2017-03-21 17:05:00 +00:00
HowToUseInstrMappings.rst
InAlloca.rst
LLVMBuild.rst Fix LLVMBuild.txt typo. NFC 2017-04-03 18:21:50 +00:00
LLVMBuild.txt
LangRef.rst llvm: Add support for "-fno-delete-null-pointer-checks" 2018-07-09 22:27:23 +00:00
Lexicon.rst [Lexicon] Add "ICE", internal compiler error 2018-04-05 14:08:16 +00:00
LibFuzzer.rst [libFuzzer] Include TEMP_MAX_LEN in Fuzzer::PrintStats. 2018-02-22 19:00:17 +00:00
LinkTimeOptimization.rst [docs] Typos and whitespace fixed in LTO docs. 2016-11-29 18:00:31 +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
MIRLangRef.rst [NFC] fix trivial typos in documents 2018-06-15 05:10:09 +00:00
Makefile.sphinx
MarkedUpDisassembly.rst
MemorySSA.rst [NFC] fix trivial typos in comments and documents 2018-01-26 08:15:29 +00:00
MergeFunctions.rst
NVPTXUsage.rst [CodeGen] Unify MBB reference format in both MIR and debug output 2017-12-04 17:18:51 +00:00
OptBisect.rst Remove opt-bisect support for "cases" in favor of debug counters 2017-03-11 01:41:03 +00:00
Packaging.rst
Passes.rst Another try to commit 323321 (aggressive instruction combine). 2018-01-25 12:06:32 +00:00
Phabricator.rst [docs] Tweak update to Phabricator docs about setting repository for diffs uploaded via web 2018-01-12 15:44:35 +00:00
ProgrammersManual.rst [NFC] fix trivial typos in documents 2018-06-15 05:10:09 +00:00
Projects.rst
README.txt Remove test commit change. 2017-06-24 20:13:32 +00:00
ReleaseNotes.rst [docs] add various sanitisers support for FreeBSD/OpenBSD 2018-06-07 16:33:48 +00:00
ReleaseProcess.rst [docs] Make ReleaseProcess.rst 80 column. NFCI 2018-01-18 14:57:55 +00:00
ReportingGuide.rst
ScudoHardenedAllocator.rst [docs] Scudo documentation minor update 2018-05-18 17:02:35 +00:00
SegmentedStacks.rst
SourceLevelDebugging.rst [docs] Update code block for compatibility with Sphinx 1.5.1 2017-11-06 11:47:24 +00:00
SphinxQuickstartTemplate.rst
StackMaps.rst [StackMaps] Increase the size of the "location size" field 2017-04-28 04:48:42 +00:00
Statepoints.rst [docs] change a few code-blocks to llvm from text 2017-07-26 14:11:23 +00:00
SystemLibrary.rst s/LLVM_ON_WIN32/_WIN32/, llvm 2018-04-29 00:45:03 +00:00
TableGenFundamentals.rst
TestSuiteMakefileGuide.rst
TestingGuide.rst [llvm] Document "%T" as deprecated in TestingGuide.rst 2018-06-19 22:22:48 +00:00
TypeMetadata.rst Fixed broken links in docs. 2017-09-22 21:10:37 +00:00
Vectorizers.rst docs: Remove reference to a deprecated flag 2018-01-23 20:22:37 +00:00
WritingAnLLVMBackend.rst [Docs] Fix typo in scheduler model documentation. enumemation->enumeration 2017-12-10 09:14:35 +00:00
WritingAnLLVMPass.rst Fixed dead links in WritingAnLLVMPass.rst 2017-11-06 09:51:39 +00:00
XRay.rst [XRay][compiler-rt+docs] Introduce __xray_log_init_mode(...). 2018-05-04 06:01:12 +00:00
XRayExample.rst Tidy some language in the xray documentation. 2018-05-27 09:19:03 +00:00
XRayFDRFormat.rst Tidy some language in the xray documentation. 2018-05-27 09:19:03 +00:00
YamlIO.rst [YAML] Add support for non-printable characters 2017-12-18 17:38:03 +00:00
conf.py The trunk version is now 7.0.0svn 2018-01-03 14:52:54 +00:00
doxygen-mainpage.dox
doxygen.cfg.in [NFC] fix trivial typos in comments and documents 2018-01-26 08:15:29 +00:00
gcc-loops.png
index.rst [Docs] Remove some WIP X86 documentation I accidentally leaked into r328031. 2018-03-21 17:32:57 +00:00
linpack-pc.png
make.bat
re_format.7
yaml2obj.rst

README.txt

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