llvm-6502/docs
Peter Collingbourne bb660fc192 Prologue support
Patch by Ben Gamari!

This redefines the `prefix` attribute introduced previously and
introduces a `prologue` attribute.  There are a two primary usecases
that these attributes aim to serve,

  1. Function prologue sigils

  2. Function hot-patching: Enable the user to insert `nop` operations
     at the beginning of the function which can later be safely replaced
     with a call to some instrumentation facility

  3. Runtime metadata: Allow a compiler to insert data for use by the
     runtime during execution. GHC is one example of a compiler that
     needs this functionality for its tables-next-to-code functionality.

Previously `prefix` served cases (1) and (2) quite well by allowing the user
to introduce arbitrary data at the entrypoint but before the function
body. Case (3), however, was poorly handled by this approach as it
required that prefix data was valid executable code.

Here we redefine the notion of prefix data to instead be data which
occurs immediately before the function entrypoint (i.e. the symbol
address). Since prefix data now occurs before the function entrypoint,
there is no need for the data to be valid code.

The previous notion of prefix data now goes under the name "prologue
data" to emphasize its duality with the function epilogue.

The intention here is to handle cases (1) and (2) with prologue data and
case (3) with prefix data.

References
----------

This idea arose out of discussions[1] with Reid Kleckner in response to a
proposal to introduce the notion of symbol offsets to enable handling of
case (3).

[1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-May/073235.html

Test Plan: testsuite

Differential Revision: http://reviews.llvm.org/D6454

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223189 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 02:08:38 +00:00
..
_static
_templates
_themes/llvm-theme
CommandGuide [llvm-symbolizer] Introduce the -dsym-hint option. 2014-10-17 00:50:19 +00:00
HistoricalNotes
TableGen Remove neverHasSideEffects support from TableGen CodeGenInstruction. Everyone should use hasSideEffects now. 2014-11-26 04:11:14 +00:00
tutorial [Docs][JIT] Update the clang++ invocation lines in the kaleidoscope docs. 2014-11-06 00:31:04 +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 Prologue support 2014-12-03 02:08:38 +00:00
BlockFrequencyTerminology.rst Fix typos 2014-05-15 01:52:21 +00:00
BranchWeightMetadata.rst
Bugpoint.rst
CMake.rst Use ninja pools to limit the number of concurrent compile/link jobs. 2014-11-19 10:30:02 +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 [sphinx cleanup] 2014-09-10 20:43:03 +00:00
CodingStandards.rst Introduce Go coding standards for LLVM. 2014-10-14 00:40:53 +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 Update documentation with link to Sea Islands documentation 2014-10-06 18:31:09 +00:00
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 Correct path to regression tests in ExtendingLLVM 2014-11-24 19:40:07 +00:00
Extensions.rst ARM: add VLA extension for WoA Itanium ABI 2014-06-09 20:18:42 +00:00
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 VMCore was renamed to IR long time ago 2014-10-29 05:20:39 +00:00
GettingStartedVS.rst Document how to select build configuration with Visual C++ IDE or command line. 2014-06-05 16:42:26 +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
HowToSubmitABug.rst Delete -std-compile-opts. 2014-10-16 20:00:02 +00:00
HowToUseAttributes.rst
HowToUseInstrMappings.rst
InAlloca.rst
index.rst R600/SI: Start implementing an assembler 2014-11-14 14:08:00 +00:00
LangRef.rst Prologue support 2014-12-03 02:08:38 +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
Makefile [OCaml] PR14083, PR9606: Only pick *.odoc files from current build target. 2014-10-28 22:45:25 +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
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MCJITDesignAndImplementation.rst Minor typo. 2014-09-05 04:56:43 +00:00
NVPTXUsage.rst
Packaging.rst
Passes.rst docs: Remove documentation for legacy PGO options 2014-06-04 06:29:38 +00:00
Phabricator.rst Phabricator doc: Explicit the fact that the patch needs to be there before the commit 2014-07-04 09:00:35 +00:00
ProgrammersManual.rst Update my previous commit to fit 80 cols... 2014-09-25 10:58:16 +00:00
Projects.rst
R600Usage.rst R600/SI: Start implementing an assembler 2014-11-14 14:08:00 +00:00
re_format.7
README.txt
ReleaseNotes.rst Prologue support 2014-12-03 02:08:38 +00:00
ReleaseProcess.rst
SegmentedStacks.rst
SourceLevelDebugging.rst Update dwarf::ApplePropertyAttributes enum to meaningful values. 2014-10-08 14:59:44 +00:00
SphinxQuickstartTemplate.rst
StackMaps.rst
Statepoints.rst [Statepoints 4/4] Statepoint infrastructure for garbage collection: Documentation 2014-12-02 19:37:00 +00:00
SystemLibrary.rst
TableGenFundamentals.rst
TestingGuide.rst [docs] Document usage of Inputs/ for extra test files. 2014-11-05 22:17:18 +00:00
TestSuiteMakefileGuide.rst
Vectorizers.rst Vectorization documentation for loop hint pragmas and Rpass diagnostics. 2014-06-27 18:30:08 +00:00
WritingAnLLVMBackend.rst configure.ac lives in autoconf/, not autotools/ 2014-11-10 22:36:04 +00:00
WritingAnLLVMPass.rst docs: Modernize some examples in WritingAnLLVMPass 2014-11-18 05:22:39 +00:00
yaml2obj.rst
YamlIO.rst [YAML] Add an optional argument EnumMask to the yaml::IO::bitSetCase(). 2014-05-23 08:07:09 +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