llvm/docs
David Majnemer 8cec2f2816 [IR] Reformulate LLVM's EH funclet IR
While we have successfully implemented a funclet-oriented EH scheme on
top of LLVM IR, our scheme has some notable deficiencies:
- catchendpad and cleanupendpad are necessary in the current design
  but they are difficult to explain to others, even to seasoned LLVM
  experts.
- catchendpad and cleanupendpad are optimization barriers.  They cannot
  be split and force all potentially throwing call-sites to be invokes.
  This has a noticable effect on the quality of our code generation.
- catchpad, while similar in some aspects to invoke, is fairly awkward.
  It is unsplittable, starts a funclet, and has control flow to other
  funclets.
- The nesting relationship between funclets is currently a property of
  control flow edges.  Because of this, we are forced to carefully
  analyze the flow graph to see if there might potentially exist illegal
  nesting among funclets.  While we have logic to clone funclets when
  they are illegally nested, it would be nicer if we had a
  representation which forbade them upfront.

Let's clean this up a bit by doing the following:
- Instead, make catchpad more like cleanuppad and landingpad: no control
  flow, just a bunch of simple operands;  catchpad would be splittable.
- Introduce catchswitch, a control flow instruction designed to model
  the constraints of funclet oriented EH.
- Make funclet scoping explicit by having funclet instructions consume
  the token produced by the funclet which contains them.
- Remove catchendpad and cleanupendpad.  Their presence can be inferred
  implicitly using coloring information.

N.B.  The state numbering code for the CLR has been updated but the
veracity of it's output cannot be spoken for.  An expert should take a
look to make sure the results are reasonable.

Reviewers: rnk, JosephTremoulet, andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D15139

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255422 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-12 05:38:55 +00:00
..
_ocamldoc [OCaml] Use a nicer style for documentation than OCaml default. 2015-07-17 06:37:59 +00:00
_static
_templates
_themes/llvm-theme
CommandGuide Revert "[llvm-profdata] Add support for weighted merge of profile data" 2015-12-04 02:13:58 +00:00
Frontend [docs][PerformanceTips] Add text on allocas and alignment 2015-09-10 17:03:10 +00:00
HistoricalNotes
TableGen Rename all references to old mailing lists to new lists.llvm.org address. 2015-08-05 03:51:17 +00:00
tutorial [Docs] Fix typo 2015-11-15 14:13:24 +00:00
AliasAnalysis.rst [PM/AA] Remove the AliasDebugger pass. 2015-08-12 22:54:47 +00:00
AMDGPUUsage.rst
ARM-BE-bitcastfail.png
ARM-BE-bitcastsuccess.png
ARM-BE-ld1.png
ARM-BE-ldr.png
Atomics.rst [CodeGen] Refactor TLI/AtomicExpand interface to make LLSC explicit. 2015-09-11 17:08:28 +00:00
BigEndianNEON.rst
BitCodeFormat.rst [CXX TLS calling convention] Add CXX TLS calling convention. 2015-12-04 17:40:13 +00:00
BitSets.rst Re-apply r247080 with order of evaluation fix. 2015-09-08 22:49:35 +00:00
BlockFrequencyTerminology.rst
BranchWeightMetadata.rst Fix typos. 2015-09-12 01:17:08 +00:00
Bugpoint.rst
BuildingLLVMWithAutotools.rst Deprecate Autoconf 2015-11-09 21:54:55 +00:00
CMake.rst [CMake] Adding LLVM_CREATE_XCODE_TOOLCHAIN to the CMake documentation page. 2015-10-15 20:12:08 +00:00
CMakeLists.txt Doxygen: add build option to use svg instead of png files for graphs 2015-08-17 23:24:17 +00:00
CodeGenerator.rst Fixing a typo in docs/CodeGenerator.rst 2015-11-13 15:14:04 +00:00
CodingStandards.rst Disable Visual C++ 2013 Debug mode assert on null pointer in some STL algorithms, 2015-08-21 17:31:03 +00:00
CommandLine.rst Add missing underlines for a docs section. NFC 2015-07-24 00:29:50 +00:00
CompileCudaWithLLVM.rst [doc] fix a wrong link 2015-11-18 22:01:44 +00:00
CompilerWriterInfo.rst ARM/AArch64: update reference documentation. 2015-12-04 16:10:48 +00:00
conf.py Docs: keep copyright years up-to-date. 2015-08-12 18:27:23 +00:00
CoverageMappingFormat.rst Fix Sphinx error about duplicate label in CommandLine.rst:1560 and CoverageMappingFormat.rst 2015-07-14 23:29:53 +00:00
DebuggingJITedCode.rst
DeveloperPolicy.rst Fix a spurious if. 2015-12-11 00:51:59 +00:00
doxygen.cfg.in Doxygen: Use mathjax to create formulas. 2015-11-25 00:50:47 +00:00
doxygen.intro
Dummy.html
ExceptionHandling.rst [IR] Reformulate LLVM's EH funclet IR 2015-12-12 05:38:55 +00:00
ExtendedIntegerResults.txt
ExtendingLLVM.rst [WinEH] Add llvm.eh.exceptionpointer intrinsic 2015-09-03 09:15:32 +00:00
Extensions.rst
FAQ.rst
FaultMaps.rst [FaultMaps] Let the frontend pre-select implicit null check candidates. 2015-06-30 21:22:32 +00:00
GarbageCollection.rst
gcc-loops.png
GetElementPtr.rst
GettingStarted.rst [OPENMP] Make -fopenmp to turn on OpenMP support by default. 2015-12-10 05:45:58 +00:00
GettingStartedVS.rst
GoldPlugin.rst
HowToAddABuilder.rst
HowToBuildOnARM.rst [Docs] Change ARM build info to CMake 2015-11-06 18:39:34 +00:00
HowToCrossCompileLLVM.rst
HowToReleaseLLVM.rst docs: Add information about helper scripts to HowToReleaseLLVM page 2015-07-31 01:02:35 +00:00
HowToSetUpLLVMStyleRTTI.rst
HowToSubmitABug.rst
HowToUseAttributes.rst
HowToUseInstrMappings.rst
InAlloca.rst
index.rst [doc] Compile CUDA with LLVM 2015-11-10 22:35:47 +00:00
LangRef.rst [IR] Reformulate LLVM's EH funclet IR 2015-12-12 05:38:55 +00:00
Lexicon.rst
LibFuzzer.rst [libFuzzer] one more trophie 2015-12-05 02:23:49 +00:00
LinkTimeOptimization.rst
linpack-pc.png
LLVMBuild.rst
LLVMBuild.txt
make.bat
Makefile Doxygen: add build option to use svg instead of png files for graphs 2015-08-17 23:24:17 +00:00
Makefile.sphinx
MakefileGuide.rst
MarkedUpDisassembly.rst
MCJIT-creation.png
MCJIT-dyld-load.png
MCJIT-engine-builder.png
MCJIT-load-object.png
MCJIT-load.png
MCJIT-resolve-relocations.png
MCJITDesignAndImplementation.rst
MergeFunctions.rst
MIRLangRef.rst MIRLangRef: Add documentation for the subregister indices. 2015-09-08 11:39:47 +00:00
NVPTXUsage.rst
Packaging.rst
Passes.rst
Phabricator.rst docs: Fix typo in Phabricator.rst 2015-08-06 16:57:49 +00:00
ProgrammersManual.rst docs: Stop using DEBUG() without DEBUG_TYPE in the ProgrammersManual 2015-10-15 18:17:44 +00:00
Projects.rst Rename all references to old mailing lists to new lists.llvm.org address. 2015-08-05 03:51:17 +00:00
re_format.7
README.txt Test Commit - Corrected spelling in README.txt. 2015-08-12 23:56:50 +00:00
ReleaseNotes.rst Deprecate Autoconf 2015-11-09 21:54:55 +00:00
ReleaseProcess.rst [OPENMP] Make -fopenmp to turn on OpenMP support by default. 2015-12-10 05:45:58 +00:00
SegmentedStacks.rst
SourceLevelDebugging.rst docs: Document function-attached metadata and IR changes from r252219. 2015-11-06 02:41:02 +00:00
SphinxQuickstartTemplate.rst
StackMaps.rst List supported architectures for StackMap section and related intrinsics 2015-07-16 21:10:46 +00:00
Statepoints.rst Fix typos. 2015-09-12 01:17:08 +00:00
SystemLibrary.rst
TableGenFundamentals.rst
TestingGuide.rst [Documentation] Add guidelines for grouping tests together. 2015-11-17 02:17:35 +00:00
TestSuiteMakefileGuide.rst
Vectorizers.rst
WritingAnLLVMBackend.rst
WritingAnLLVMPass.rst Fix another reference to in-source builds 2015-10-23 17:42:51 +00:00
yaml2obj.rst Summary: 2015-07-28 16:18:17 +00:00
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 reachability of external links in the documentation can be checked by
running:

    cd docs/
    make -f Makefile.sphinx linkcheck