diff options
Diffstat (limited to 'llvm/docs/GettingStarted.rst')
| -rw-r--r-- | llvm/docs/GettingStarted.rst | 160 |
1 files changed, 63 insertions, 97 deletions
diff --git a/llvm/docs/GettingStarted.rst b/llvm/docs/GettingStarted.rst index f079da77f2b..5cd0fbf2366 100644 --- a/llvm/docs/GettingStarted.rst +++ b/llvm/docs/GettingStarted.rst @@ -132,7 +132,7 @@ Here's the short story for getting up and running quickly with LLVM: `below`_. Consult the `Getting Started with LLVM`_ section for detailed information on -configuring and compiling LLVM. Go to `Program Layout`_ to learn about the +configuring and compiling LLVM. Go to `Directory Layout`_ to learn about the layout of the source code tree. Requirements @@ -936,40 +936,38 @@ use this command instead of the 'echo' command above: .. _Program Layout: .. _general layout: -Program Layout -============== +Directory Layout +================ One useful source of information about the LLVM source base is the LLVM `doxygen -<http://www.doxygen.org/>`_ documentation available at +<http://www.doxygen.org/>`_ documentation available at `<http://llvm.org/doxygen/>`_. The following is a brief introduction to code layout: ``llvm/examples`` ----------------- -This directory contains some simple examples of how to use the LLVM IR and JIT. +Simple examples using the LLVM IR and JIT. ``llvm/include`` ---------------- -This directory contains public header files exported from the LLVM library. The -three main subdirectories of this directory are: +Public header files exported from the LLVM library. The three main subdirectories: ``llvm/include/llvm`` - This directory contains all of the LLVM specific header files. This directory - also has subdirectories for different portions of LLVM: ``Analysis``, - ``CodeGen``, ``Target``, ``Transforms``, etc... + All LLVM-specific header files, and subdirectories for different portions of + LLVM: ``Analysis``, ``CodeGen``, ``Target``, ``Transforms``, etc... ``llvm/include/llvm/Support`` - This directory contains generic support libraries that are provided with LLVM - but not necessarily specific to LLVM. For example, some C++ STL utilities and - a Command Line option processing library store their header files here. + Generic support libraries provided with LLVM but not necessarily specific to + LLVM. For example, some C++ STL utilities and a Command Line option processing + library store header files here. ``llvm/include/llvm/Config`` - This directory contains header files configured by the ``configure`` script. + Header files configured by the ``configure`` script. They wrap "standard" UNIX and C header files. Source code can include these header files which automatically take care of the conditional #includes that the ``configure`` script generates. @@ -977,103 +975,76 @@ three main subdirectories of this directory are: ``llvm/lib`` ------------ -This directory contains most of the source files of the LLVM system. In LLVM, -almost all code exists in libraries, making it very easy to share code among the -different `tools`_. +Most source files are here. By putting code in libraries, LLVM makes it easy to +share code among the `tools`_. ``llvm/lib/IR/`` - This directory holds the core LLVM source files that implement core classes - like Instruction and BasicBlock. + Core LLVM source files that implement core classes like Instruction and + BasicBlock. ``llvm/lib/AsmParser/`` - This directory holds the source code for the LLVM assembly language parser - library. + Source code for the LLVM assembly language parser library. ``llvm/lib/Bitcode/`` - This directory holds code for reading and write LLVM bitcode. + Code for reading and writing bitcode. ``llvm/lib/Analysis/`` - This directory contains a variety of different program analyses, such as - Dominator Information, Call Graphs, Induction Variables, Interval - Identification, Natural Loop Identification, etc. + A variety of program analyses, such as Call Graphs, Induction Variables, + Natural Loop Identification, etc. ``llvm/lib/Transforms/`` - This directory contains the source code for the LLVM to LLVM program - transformations, such as Aggressive Dead Code Elimination, Sparse Conditional - Constant Propagation, Inlining, Loop Invariant Code Motion, Dead Global - Elimination, and many others. + IR-to-IR program transformations, such as Aggressive Dead Code Elimination, + Sparse Conditional Constant Propagation, Inlining, Loop Invariant Code Motion, + Dead Global Elimination, and many others. ``llvm/lib/Target/`` - This directory contains files that describe various target architectures for - code generation. For example, the ``llvm/lib/Target/X86`` directory holds the - X86 machine description while ``llvm/lib/Target/ARM`` implements the ARM - backend. + Files describing target architectures for code generation. For example, + ``llvm/lib/Target/X86`` holds the X86 machine description. ``llvm/lib/CodeGen/`` - This directory contains the major parts of the code generator: Instruction - Selector, Instruction Scheduling, and Register Allocation. + The major parts of the code generator: Instruction Selector, Instruction + Scheduling, and Register Allocation. ``llvm/lib/MC/`` - (FIXME: T.B.D.) - -``llvm/lib/Debugger/`` - - This directory contains the source level debugger library that makes it - possible to instrument LLVM programs so that a debugger could identify source - code locations at which the program is executing. + (FIXME: T.B.D.) ....? ``llvm/lib/ExecutionEngine/`` - This directory contains libraries for executing LLVM bitcode directly at - runtime in both interpreted and JIT compiled fashions. + Libraries for directly executing bitcode at runtime in interpreted and + JIT-compiled scenarios. ``llvm/lib/Support/`` - This directory contains the source code that corresponds to the header files - located in ``llvm/include/ADT/`` and ``llvm/include/Support/``. + Source code that corresponding to the header files in ``llvm/include/ADT/`` + and ``llvm/include/Support/``. ``llvm/projects`` ----------------- -This directory contains projects that are not strictly part of LLVM but are -shipped with LLVM. This is also the directory where you should create your own -LLVM-based projects. - -``llvm/runtime`` ----------------- - -This directory contains libraries which are compiled into LLVM bitcode and used -when linking programs with the Clang front end. Most of these libraries are -skeleton versions of real libraries; for example, libc is a stripped down -version of glibc. - -Unlike the rest of the LLVM suite, this directory needs the LLVM GCC front end -to compile. +Projects not strictly part of LLVM but shipped with LLVM. This is also the +directory for creating your own LLVM-based projects which leverage the LLVM +build system. ``llvm/test`` ------------- -This directory contains feature and regression tests and other basic sanity -checks on the LLVM infrastructure. These are intended to run quickly and cover a -lot of territory without being exhaustive. +Feature and regression tests and other sanity checks on LLVM infrastructure. These +are intended to run quickly and cover a lot of territory without being exhaustive. ``test-suite`` -------------- -This is not a directory in the normal llvm module; it is a separate Subversion -module that must be checked out (usually to ``projects/test-suite``). This -module contains a comprehensive correctness, performance, and benchmarking test -suite for LLVM. It is a separate Subversion module because not every LLVM user -is interested in downloading or building such a comprehensive test suite. For -further details on this test suite, please see the :doc:`Testing Guide +A comprehensive correctness, performance, and benchmarking test suite for LLVM. +Comes in a separate Subversion module because not every LLVM user is interested +in such a comprehensive suite. For details see the :doc:`Testing Guide <TestingGuide>` document. .. _tools: @@ -1081,7 +1052,7 @@ further details on this test suite, please see the :doc:`Testing Guide ``llvm/tools`` -------------- -The **tools** directory contains the executables built out of the libraries +Executables built out of the libraries above, which form the main part of the user interface. You can always get help for a tool by typing ``tool_name -help``. The following is a brief introduction to the most important tools. More detailed information is in @@ -1129,72 +1100,67 @@ the `Command Guide <CommandGuide/index.html>`_. ``opt`` ``opt`` reads LLVM bitcode, applies a series of LLVM to LLVM transformations - (which are specified on the command line), and then outputs the resultant - bitcode. The '``opt -help``' command is a good way to get a list of the + (which are specified on the command line), and outputs the resultant + bitcode. '``opt -help``' is a good way to get a list of the program transformations available in LLVM. - ``opt`` can also be used to run a specific analysis on an input LLVM bitcode - file and print out the results. It is primarily useful for debugging + ``opt`` can also run a specific analysis on an input LLVM bitcode + file and print the results. Primarily useful for debugging analyses, or familiarizing yourself with what an analysis does. ``llvm/utils`` -------------- -This directory contains utilities for working with LLVM source code, and some of -the utilities are actually required as part of the build process because they -are code generators for parts of LLVM infrastructure. +Utilities for working with LLVM source code; some are part of the build process +because they are code generators for parts of the infrastructure. ``codegen-diff`` - ``codegen-diff`` is a script that finds differences between code that LLC - generates and code that LLI generates. This is a useful tool if you are + ``codegen-diff`` finds differences between code that LLC + generates and code that LLI generates. This is useful if you are debugging one of them, assuming that the other generates correct output. For the full user manual, run ```perldoc codegen-diff'``. ``emacs/`` - The ``emacs`` directory contains syntax-highlighting files which will work - with Emacs and XEmacs editors, providing syntax highlighting support for LLVM - assembly files and TableGen description files. For information on how to use - the syntax files, consult the ``README`` file in that directory. + Emacs and XEmacs syntax highlighting for LLVM assembly files and TableGen + description files. See the ``README`` for information on using them. ``getsrcs.sh`` - The ``getsrcs.sh`` script finds and outputs all non-generated source files, - which is useful if one wishes to do a lot of development across directories - and does not want to individually find each file. One way to use it is to run, - for example: ``xemacs `utils/getsources.sh``` from the top of your LLVM source + Finds and outputs all non-generated source files, + useful if one wishes to do a lot of development across directories + and does not want to find each file. One way to use it is to run, + for example: ``xemacs `utils/getsources.sh``` from the top of the LLVM source tree. ``llvmgrep`` - This little tool performs an ``egrep -H -n`` on each source file in LLVM and + Performs an ``egrep -H -n`` on each source file in LLVM and passes to it a regular expression provided on ``llvmgrep``'s command - line. This is a very efficient way of searching the source base for a + line. This is an efficient way of searching the source base for a particular regular expression. ``makellvm`` - The ``makellvm`` script compiles all files in the current directory and then + Compiles all files in the current directory, then compiles and links the tool that is the first argument. For example, assuming - you are in the directory ``llvm/lib/Target/Sparc``, if ``makellvm`` is in your - path, simply running ``makellvm llc`` will make a build of the current + you are in ``llvm/lib/Target/Sparc``, if ``makellvm`` is in your + path, running ``makellvm llc`` will make a build of the current directory, switch to directory ``llvm/tools/llc`` and build it, causing a re-linking of LLC. ``TableGen/`` - The ``TableGen`` directory contains the tool used to generate register + Contains the tool used to generate register descriptions, instruction set descriptions, and even assemblers from common TableGen description files. ``vim/`` - The ``vim`` directory contains syntax-highlighting files which will work with - the VIM editor, providing syntax highlighting support for LLVM assembly files - and TableGen description files. For information on how to use the syntax - files, consult the ``README`` file in that directory. + vim syntax-highlighting for LLVM assembly files + and TableGen description files. See the ``README`` for how to use them. .. _simple example: |
