llvm-6502/docs
Adrian Prantl 02474a32eb Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

Note: I accidentally committed a bogus older version of this patch previously.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218787 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-01 18:55:02 +00:00
..
_static
_templates
_themes/llvm-theme
CommandGuide [LIT] Remove documentation for method since it does not exist 2014-08-21 18:52:58 +00:00
HistoricalNotes
TableGen Document !and. Fix !shl and friends -- they provide binary operations. 2014-09-03 13:17:03 +00:00
tutorial
AliasAnalysis.rst
ARM-BE-bitcastfail.png
ARM-BE-bitcastsuccess.png
ARM-BE-ld1.png
ARM-BE-ldr.png
Atomics.rst [docs] Fixed a typo in Atomics.rst 2014-09-23 17:35:28 +00:00
BigEndianNEON.rst
BitCodeFormat.rst Fix sphinx warning. 2014-09-18 21:54:02 +00:00
BlockFrequencyTerminology.rst
BranchWeightMetadata.rst
Bugpoint.rst
CMake.rst Introduce -DLLVM_USE_SANITIZER=Undefined CMake option to build UBSan-ified version of LLVM/Clang. 2014-08-29 00:50:36 +00:00
CMakeLists.txt
CodeGenerator.rst [sphinx cleanup] 2014-09-10 20:43:03 +00:00
CodingStandards.rst CodingStandards: Document std::equal misbehaviour 2014-08-19 16:49:40 +00:00
CommandLine.rst
CompilerWriterInfo.rst
conf.py Update LLVM version: 3.5 => 3.6 2014-07-28 22:10:52 +00:00
CoverageMappingFormat.rst Docs: add documentation for the coverage mapping format. 2014-08-19 17:05:58 +00:00
DebuggingJITedCode.rst
DeveloperPolicy.rst Document what backwards compatibility we provide for bitcode. 2014-07-23 22:43:22 +00:00
doxygen.cfg.in
doxygen.css
doxygen.footer
doxygen.header
doxygen.intro
Dummy.html
ExceptionHandling.rst
ExtendedIntegerResults.txt
ExtendingLLVM.rst
Extensions.rst
FAQ.rst
GarbageCollection.rst Remove the TargetMachine forwards for TargetSubtargetInfo based 2014-08-04 21:25:23 +00:00
gcc-loops.png
GetElementPtr.rst
GettingStarted.rst Delete support for AuroraUX. 2014-08-14 15:15:09 +00:00
GettingStartedVS.rst
GoldPlugin.rst
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
HowToSubmitABug.rst
HowToUseAttributes.rst
HowToUseInstrMappings.rst
InAlloca.rst inalloca: *Really* fix the docs 2014-03-27 01:38:48 +00:00
index.rst fix a typo in doumentation index. 2014-09-26 06:59:15 +00:00
LangRef.rst [docs] Mention character array constants in docs/LangRef.rst 2014-09-11 12:02:59 +00:00
Lexicon.rst [docs] Document what "NFC" means in a commit message. 2014-09-06 00:19:16 +00:00
LinkTimeOptimization.rst
linpack-pc.png
LLVMBuild.rst
LLVMBuild.txt
make.bat [docs] Stub out structure for Sphinx-based docs. 2012-04-19 16:31:19 +00:00
Makefile
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
MCJIT-creation.png
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MCJIT-engine-builder.png
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MCJIT-load.png
MCJIT-resolve-relocations.png
MCJITDesignAndImplementation.rst Minor typo. 2014-09-05 04:56:43 +00:00
NVPTXUsage.rst
Packaging.rst
Passes.rst
Phabricator.rst
ProgrammersManual.rst Update my previous commit to fit 80 cols... 2014-09-25 10:58:16 +00:00
Projects.rst
re_format.7
README.txt [docs] Add a note to docs/README.txt 2014-04-22 21:47:53 +00:00
ReleaseNotes.rst LTO: introduce object file-based on-disk module format. 2014-09-18 21:28:49 +00:00
ReleaseProcess.rst
SegmentedStacks.rst
SourceLevelDebugging.rst Move the complex address expression out of DIVariable and into an extra 2014-10-01 18:55:02 +00:00
SphinxQuickstartTemplate.rst
StackMaps.rst
SystemLibrary.rst
TableGenFundamentals.rst
TestingGuide.rst
TestSuiteMakefileGuide.rst
Vectorizers.rst
WritingAnLLVMBackend.rst
WritingAnLLVMPass.rst
yaml2obj.rst
YamlIO.rst

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