| Line 59: | Line 59: | ||
They are used in the templates and explained in more detail below. | They are used in the templates and explained in more detail below. | ||
Generally | Generally the macros should just work and do the right thing, but if necessary | ||
a macro can be replaced by its expansions of course | a macro can be replaced by its expansions of course | ||
and then tweaked in order to get a package to build for Fedora. | and then tweaked in order to get a package to build for Fedora. | ||
Revision as of 15:54, 4 February 2011
Haskell Packaging Guidelines
This page documents the guidelines and conventions for packaging Haskell projects in Fedora.
GHC (Glasgow Haskell Compiler) is the current mainstream Haskell compiler.
Most Haskell packages are now released on Haskage and use the Haskell Cabal package system. So currently these guidelines mostly focus on packaging for GHC using Cabal.
Spec file templates
There are three types of Haskell Cabal packages: binary only (Bin), library only (Lib), and binary and library (BinLib). Templates are provided for all three cases since they are slightly different:
It is recommended to use cabal2spec to create .spec files using these templates directly from a Cabal package or .cabal file for any of the three cases, since following the standard packaging templates lower the maintenance burden considerably across Fedora's Haskell packages. With minor editing the .spec files should then build for most general Cabal packages: for example it may be necessary to specify BuildRequires for build dependencies and Requires for any runtime dependencies. Please report any problems in bugzilla (in the cabal2spec component of the Fedora product).
Naming
Haskell Bin and BinLib packages should follow the usual Fedora Package Naming Guidelines for base package naming: ie follow the upstream name. Examples include projects like darcs and xmonad. BinLib packages SHOULD subpackage their libraries with naming following Lib packages.
For example the xmonad package has library subpackages ghc-xmonad, ghc-xmonad-devel, and ghc-xmonad-prof.
The name of Haskell Lib packages built for ghc are prefixed by "ghc-". For example the zlib library is named ghc-zlib, and the QuickCheck library is named ghc-QuickCheck.
If a library is packaged for more than one Haskell compiler or interpreter, the base name should instead be prefixed with haskell, e.g. haskell-X11. Such a package would then have subpackages for each compiler and/or interpreter it is built for (e.g. ghc-X11, hugs98-X11, etc).
Package naming preserves case to follow the upstream naming conventions as closely as possible.
GHC uses static libraries by default, but now supports shared libraries. Lib and BinLib packages should provide static, shared, and profiling libraries. The shared libraries live in the base library package, static library and header files in the -devel subpackage and profiling libraries in the -prof subpackage.
Executables in Bin and BinLib packages should be dynamically linked to shared libraries.
Static linking means that when updating any library, all packages that depend on it will also need to be rebuilt before they see any changes, and in the event of a security advisory, all of them need to be rebuilt also.
This is not true for linking to other languages using the Foreign Function Interface (FFI). When linking to these libraries, the standard dynamic linker is used.
Note: the situation is similar to OCaml, and the usual rules that apply there apply here as well.
Keep in mind though, that some special packages may still do code generation at runtime in which case they may need Requires as well as BuildRequires for their dependencies: examples include xmonad and yi which may require their devel package to be present to allow user configuration or customization.
Debug Information
Objects compiled with ghc do not include useful debug info, so debuginfo packages should be disabled:
%global debug_package %{nil}
RPM Macros
The templates all have buildrequires for ghc-rpm-macros, which provides macros.ghc to assist with packaging Haskell Cabal packages.
The main commonly needed macros are:
- %ghc_bin_build
- %ghc_bin_install
- %ghc_lib_build
- %ghc_lib_install
- %ghc_lib_package
- %ghc_binlib_package
They are used in the templates and explained in more detail below.
Generally the macros should just work and do the right thing, but if necessary a macro can be replaced by its expansions of course and then tweaked in order to get a package to build for Fedora.
Bin packages
Bin packages use dynamic linking by default, but this can be disabled if necessary by defining the without_dynamic macro.
%ghc_bin_buildis used to configure and build bin packages. It runs:%cabal_configure: configure the package for building and dynamic linking.%cabal build: builds the package.
%ghc_bin_installis used to install bin packages. It runs:%cabal_install: installs the package.%ghc_strip_dynlinked: strips the dynamically linked binary.
Lib and BinLib packages
%ghc_lib_buildis used to configure, build and generate documentation for lib and binlib packages. It runs:%cabal_configure --ghc -p: configures the package for building with ghc and profiling. Libraries should build profiling versions of their static libraries.%cabal build: builds the package.%cabal haddock: generates HTML library documentation from the source code. If necessary (if e.g. documentation is failing to build for some reason) this can be skipped by definingwithout_haddock.
%ghc_lib_installis used to install lib and binlib packages. It runs:%cabal_install: installs the package without registering it in ghc-pkg.%cabal_pkg_conf: creates ghc-pkg metadata for package installation time%ghc_gen_filelists: generates rpm filelists.%ghc_strip_dynlinked: strips dynamically linked objects.
Directories
GHC libraries are installed under %ghcpkgdir/%{pkg_name}-%{version}:
Library documentation lives under %ghclibdocdir/%{pkg_name}-%{version}.
File lists
Filelists for shared, devel and profiling library subpackages are generated using the following macro:
%ghc_gen_filelists
It generates three filelists: ghc-%{pkg_name}.files, ghc-%{pkg_name}-devel.files, and ghc-%{pkg_name}-prof.files.
The files sections are boilerplate generated by %ghc_lib_package and %ghc_binlib_package.
If you need to add additional files (e.g. extra %doc files or datadir files say) they can simply be added by echo'ing to the appropriate ".files" list.
Install scripts
Library devel packages include a ".conf" metadata file generated by %cabal_pkg_conf as part of %ghc_lib_install.
The %post and %postun scripts regenerate ghc's package cache by running:
%ghc_pkg_recache
and also may regenerate the Haddock documentation index with
%ghc_reindex_haddock
References