diff --git a/docs/LLVMBuild.html b/docs/LLVMBuild.html deleted file mode 100644 index 9e7f8c76577..00000000000 --- a/docs/LLVMBuild.html +++ /dev/null @@ -1,368 +0,0 @@ - - - - - LLVMBuild Documentation - - - - -

LLVMBuild Guide

- -
    -
  1. Introduction
    2. -
  2. Project Organization
    3. -
  3. Build Integration
    4. -
  4. Component Overview
    5. -
  5. Format Reference
    6. -
- - -

Introduction

- - -
-

This document describes the LLVMBuild organization and files which - we use to describe parts of the LLVM ecosystem. For description of specific - LLVMBuild related tools, please see the command guide.

- -

LLVM is designed to be a modular set of libraries which can be flexibly - mixed together in order to build a variety of tools, like compilers, JITs, - custom code generators, optimization passes, interpreters, and so on. Related - projects in the LLVM system like Clang and LLDB also tend to follow this - philosophy.

- -

In order to support this usage style, LLVM has a fairly strict structure as - to how the source code and various components are organized. The - LLVMBuild.txt files are the explicit specification of that structure, - and are used by the build systems and other tools in order to develop the LLVM - project.

-
- - -

Project Organization

- - - - -
-

The source code for LLVM projects using the LLVMBuild system (LLVM, Clang, - and LLDB) is organized into components, which define the separate - pieces of functionality that make up the project. These projects may consist - of many libraries, associated tools, build tools, or other utility tools (for - example, testing tools).

- -

For the most part, the project contents are organized around defining one - main component per each subdirectory. Each such directory contains - an LLVMBuild.txt which contains the component definitions.

- -

The component descriptions for the project as a whole are automatically - gathered by the LLVMBuild tools. The tools automatically traverse the source - directory structure to find all of the component description files. NOTE: For - performance/sanity reasons, we only traverse into subdirectories when the - parent itself contains an LLVMBuild.txt description file.

-
- - -

Build Integration

- - -
-

The LLVMBuild files themselves are just a declarative way to describe the - project structure. The actual building of the LLVM project is handled by - another build system (currently we support - both Makefiles - and CMake.

- -

The build system implementation will load the relevant contents of the - LLVMBuild files and use that to drive the actual project build. Typically, the - build system will only need to load this information at "configure" time, and - use it to generative native information. Build systems will also handle - automatically reconfiguring their information when the contents of - the LLVMBuild.txt files change.

- -

Developers generally are not expected to need to be aware of the details of - how the LLVMBuild system is integrated into their build. Ideally, LLVM - developers who are not working on the build system would only ever need to - modify the contents of the LLVMBuild.txt description files (although we - have not reached this goal yet).

- -

For more information on the utility tool we provide to help interfacing - with the build system, please see - the llvm-build - documentation.

-
- - -

Component Overview

- - -
-

As mentioned earlier, LLVM projects are organized into - logical components. Every component is typically grouped into its - own subdirectory. Generally, a component is organized around a coherent group - of sources which have some kind of clear API separation from other parts of - the code.

- -

LLVM primarily uses the following types of components:

- - -

Components are described using LLVMBuild.txt files in the - directories that define the component. See - the Format Reference section for information on - the exact format of these files.

-
- - -

LLVMBuild Format Reference

- - -
-

LLVMBuild files are written in a simple variant of the INI or configuration - file format (Wikipedia - entry). The format defines a list of sections each of which may contain - some number of properties. A simple example of the file format is below:

-
- 
-; Comments start with a semi-colon.
-
-; Sections are declared using square brackets.
-[component_0]
-
-; Properties are declared using '=' and are contained in the previous section.
-;
-; We support simple string and boolean scalar values and list values, where
-; items are separated by spaces. There is no support for quoting, and so
-; property values may not contain spaces.
-property_name = property_value
-list_property_name = value_1 value_2 ... value_n
-boolean_property_name = 1 (or 0)
-
-
- -

LLVMBuild files are expected to define a strict set of sections and - properties. An typical component description file for a library - component would look typically look like the following example:

-
- 
-[component_0]
-type = Library
-name = Linker
-parent = Libraries
-required_libraries = Archive BitReader Core Support TransformUtils
-
-
- -

A full description of the exact sections and properties which are allowed - follows.

- -

Each file may define exactly one common component, named "common". The - common component may define the following properties:

- - -

Each file may define multiple components. Each component is described by a - section who name starts with "component". The remainder of the section name is - ignored, but each section name must be unique. Typically components are just - number in order for files with multiple components ("component_0", - "component_1", and so on).

- -

Section names not matching this format (or the "common" section) are - currently unused and are disallowed.

- -

Every component is defined by the properties in the section. The exact list - of properties that are allowed depends on the component - type. Components may not define any properties other than those - expected by the component type.

- -

Every component must define the following properties:

- - -

Components may define the following properties:

- - -

The following section lists the available component types, as well as the - properties which are associated with that component.

- - -
- - -
-
- Valid CSS - Valid HTML 4.01 - - The LLVM Compiler Infrastructure
- Last modified: $Date$ -
- - diff --git a/docs/LLVMBuild.rst b/docs/LLVMBuild.rst new file mode 100644 index 00000000000..d9215dd8eb5 --- /dev/null +++ b/docs/LLVMBuild.rst @@ -0,0 +1,325 @@ +=============== +LLVMBuild Guide +=============== + +.. contents:: + :local: + +Introduction +============ + +This document describes the ``LLVMBuild`` organization and files which +we use to describe parts of the LLVM ecosystem. For description of +specific LLVMBuild related tools, please see the command guide. + +LLVM is designed to be a modular set of libraries which can be flexibly +mixed together in order to build a variety of tools, like compilers, +JITs, custom code generators, optimization passes, interpreters, and so +on. Related projects in the LLVM system like Clang and LLDB also tend to +follow this philosophy. + +In order to support this usage style, LLVM has a fairly strict structure +as to how the source code and various components are organized. The +``LLVMBuild.txt`` files are the explicit specification of that +structure, and are used by the build systems and other tools in order to +develop the LLVM project. + +Project Organization +==================== + +The source code for LLVM projects using the LLVMBuild system (LLVM, +Clang, and LLDB) is organized into *components*, which define the +separate pieces of functionality that make up the project. These +projects may consist of many libraries, associated tools, build tools, +or other utility tools (for example, testing tools). + +For the most part, the project contents are organized around defining +one main component per each subdirectory. Each such directory contains +an ``LLVMBuild.txt`` which contains the component definitions. + +The component descriptions for the project as a whole are automatically +gathered by the LLVMBuild tools. The tools automatically traverse the +source directory structure to find all of the component description +files. NOTE: For performance/sanity reasons, we only traverse into +subdirectories when the parent itself contains an ``LLVMBuild.txt`` +description file. + +Build Integration +================= + +The LLVMBuild files themselves are just a declarative way to describe +the project structure. The actual building of the LLVM project is +handled by another build system (currently we support both +:doc:`Makefiles ` and :doc:`CMake `). + +The build system implementation will load the relevant contents of the +LLVMBuild files and use that to drive the actual project build. +Typically, the build system will only need to load this information at +"configure" time, and use it to generative native information. Build +systems will also handle automatically reconfiguring their information +when the contents of the ``LLVMBuild.txt`` files change. + +Developers generally are not expected to need to be aware of the details +of how the LLVMBuild system is integrated into their build. Ideally, +LLVM developers who are not working on the build system would only ever +need to modify the contents of the ``LLVMBuild.txt`` description files +(although we have not reached this goal yet). + +For more information on the utility tool we provide to help interfacing +with the build system, please see the :doc:`llvm-build +` documentation. + +Component Overview +================== + +As mentioned earlier, LLVM projects are organized into logical +*components*. Every component is typically grouped into its own +subdirectory. Generally, a component is organized around a coherent +group of sources which have some kind of clear API separation from other +parts of the code. + +LLVM primarily uses the following types of components: + +- *Libraries* - Library components define a distinct API which can be + independently linked into LLVM client applications. Libraries typically + have private and public header files, and may specify a link of required + libraries that they build on top of. +- *Build Tools* - Build tools are applications which are designed to be run + as part of the build process (typically to generate other source files). + Currently, LLVM uses one main build tool called :doc:`TableGen + ` to generate a variety of source files. +- *Tools* - Command line applications which are built using the LLVM + component libraries. Most LLVM tools are small and are primarily + frontends to the library interfaces. + +Components are described using ``LLVMBuild.txt`` files in the directories +that define the component. See the `LLVMBuild Format Reference`_ section +for information on the exact format of these files. + +LLVMBuild Format Reference +========================== + +LLVMBuild files are written in a simple variant of the INI or configuration +file format (`Wikipedia entry`_). The format defines a list of sections +each of which may contain some number of properties. A simple example of +the file format is below: + +.. _Wikipedia entry: http://en.wikipedia.org/wiki/INI_file + +.. code-block:: ini + + ; Comments start with a semi-colon. + + ; Sections are declared using square brackets. + [component_0] + + ; Properties are declared using '=' and are contained in the previous section. + ; + ; We support simple string and boolean scalar values and list values, where + ; items are separated by spaces. There is no support for quoting, and so + ; property values may not contain spaces. + property_name = property_value + list_property_name = value_1 value_2 ... value_n + boolean_property_name = 1 (or 0) + +LLVMBuild files are expected to define a strict set of sections and +properties. An typical component description file for a library +component would look typically look like the following example: + +.. code-block:: ini + + [component_0] + type = Library + name = Linker + parent = Libraries + required_libraries = Archive BitReader Core Support TransformUtils + +A full description of the exact sections and properties which are +allowed follows. + +Each file may define exactly one common component, named ``common``. The +common component may define the following properties: + +- ``subdirectories`` **[optional]** + + If given, a list of the names of the subdirectories from the current + subpath to search for additional LLVMBuild files. + +Each file may define multiple components. Each component is described by a +section who name starts with ``component``. The remainder of the section +name is ignored, but each section name must be unique. Typically components +are just number in order for files with multiple components +(``component_0``, ``component_1``, and so on). + +.. warning:: + + Section names not matching this format (or the ``common`` section) are + currently unused and are disallowed. + +Every component is defined by the properties in the section. The exact +list of properties that are allowed depends on the component type. +Components **may not** define any properties other than those expected +by the component type. + +Every component must define the following properties: + +- ``type`` **[required]** + + The type of the component. Supported component types are detailed + below. Most components will define additional properties which may be + required or optional. + +- ``name`` **[required]** + + The name of the component. Names are required to be unique across the + entire project. + +- ``parent`` **[required]** + + The name of the logical parent of the component. Components are + organized into a logical tree to make it easier to navigate and + organize groups of components. The parents have no semantics as far + as the project build is concerned, however. Typically, the parent + will be the main component of the parent directory. + + Components may reference the root pseudo component using ``$ROOT`` to + indicate they should logically be grouped at the top-level. + +Components may define the following properties: + +- ``dependencies`` **[optional]** + + If specified, a list of names of components which *must* be built + prior to this one. This should only be exactly those components which + produce some tool or source code required for building the component. + + .. note:: + + ``Group`` and ``LibraryGroup`` components have no semantics for the + actual build, and are not allowed to specify dependencies. + +The following section lists the available component types, as well as +the properties which are associated with that component. + +- ``type = Group`` + + Group components exist purely to allow additional arbitrary structuring + of the logical components tree. For example, one might define a + ``Libraries`` group to hold all of the root library components. + + ``Group`` components have no additionally properties. + +- ``type = Library`` + + Library components define an individual library which should be built + from the source code in the component directory. + + Components with this type use the following properties: + + - ``library_name`` **[optional]** + + If given, the name to use for the actual library file on disk. If + not given, the name is derived from the component name itself. + + - ``required_libraries`` **[optional]** + + If given, a list of the names of ``Library`` or ``LibraryGroup`` + components which must also be linked in whenever this library is + used. That is, the link time dependencies for this component. When + tools are built, the build system will include the transitive closure + of all ``required_libraries`` for the components the tool needs. + + - ``add_to_library_groups`` **[optional]** + + If given, a list of the names of ``LibraryGroup`` components which + this component is also part of. This allows nesting groups of + components. For example, the ``X86`` target might define a library + group for all of the ``X86`` components. That library group might + then be included in the ``all-targets`` library group. + + - ``installed`` **[optional]** **[boolean]** + + Whether this library is installed. Libraries that are not installed + are only reported by ``llvm-config`` when it is run as part of a + development directory. + +- ``type = LibraryGroup`` + + ``LibraryGroup`` components are a mechanism to allow easy definition of + useful sets of related components. In particular, we use them to easily + specify things like "all targets", or "all assembly printers". + + Components with this type use the following properties: + + - ``required_libraries`` **[optional]** + + See the ``Library`` type for a description of this property. + + - ``add_to_library_groups`` **[optional]** + + See the ``Library`` type for a description of this property. + +- ``type = TargetGroup`` + + ``TargetGroup`` components are an extension of ``LibraryGroup``\s, + specifically for defining LLVM targets (which are handled specially in a + few places). + + The name of the component should always be the name of the target. + + Components with this type use the ``LibraryGroup`` properties in + addition to: + + - ``has_asmparser`` **[optional]** **[boolean]** + + Whether this target defines an assembly parser. + + - ``has_asmprinter`` **[optional]** **[boolean]** + + Whether this target defines an assembly printer. + + - ``has_disassembler`` **[optional]** **[boolean]** + + Whether this target defines a disassembler. + + - ``has_jit`` **[optional]** **[boolean]** + + Whether this target supports JIT compilation. + +- ``type = Tool`` + + ``Tool`` components define standalone command line tools which should be + built from the source code in the component directory and linked. + + Components with this type use the following properties: + + - ``required_libraries`` **[optional]** + + If given, a list of the names of ``Library`` or ``LibraryGroup`` + components which this tool is required to be linked with. + + .. note:: + + The values should be the component names, which may not always + match up with the actual library names on disk. + + Build systems are expected to properly include all of the libraries + required by the linked components (i.e., the transitive closure of + ``required_libraries``). + + Build systems are also expected to understand that those library + components must be built prior to linking -- they do not also need + to be listed under ``dependencies``. + +- ``type = BuildTool`` + + ``BuildTool`` components are like ``Tool`` components, except that the + tool is supposed to be built for the platform where the build is running + (instead of that platform being targetted). Build systems are expected + to handle the fact that required libraries may need to be built for + multiple platforms in order to be able to link this tool. + + ``BuildTool`` components currently use the exact same properties as + ``Tool`` components, the type distinction is only used to differentiate + what the tool is built for. + diff --git a/docs/development_process.rst b/docs/development_process.rst index 4fc20b34129..74324b98a60 100644 --- a/docs/development_process.rst +++ b/docs/development_process.rst @@ -8,6 +8,7 @@ Development Process Documentation MakefileGuide Projects + LLVMBuild * :ref:`projects` @@ -16,7 +17,7 @@ Development Process Documentation tree) allow the project code to be located outside (or inside) the ``llvm/`` tree, while using LLVM header files and libraries. -* `LLVMBuild Documentation `_ +* :doc:`LLVMBuild` Describes the LLVMBuild organization and files used by LLVM to specify component descriptions.