Release 0.10

Highlights

• The minimum supported Bazel version is now 0.27.

  rules_haskell supports Bazel up to 0.28.
  0.27 is a LTS release, which means upstream guarantees all new
  releases are backwards-compatible to it for 3 months. See the Bazel
  Stability
  blog post for more information.

• The repository name has changed, to follow the
  new Bazel rule guidelines. It was
  previously called @io_tweag_rules_haskell. It is now called
  @rules_haskell. You should adapt your WORKSPACE file to match
  this, as well as your .bazelrc.local file, if any.

• haskell_cabal_library/haskell_cabal_binary: Both use cabal to
  build Haskell package dependencies.

• stack_snapshot: Uses stack’s dependency resolving algorithm to
  generate haskell_cabal_library targets automatically.
  Requires stack > 2.1, which it will download if cannot be found in
  PATH.

• It is now possible to statically link Haskell libraries in CC
  binaries.

• A new example has been added.

  cat_hs: is an example of a non-trivial application
  with multiple third-party dependencies downloaded from Hackage,
  C library dependencies and split up into multiple libraries and
  a binary. We use a rule wrapping Cabal to build the Hackage
  dependencies. This example requires Nix installed. It is used to
  build (or download from a binary cache) the C library dependencies.

• Improved coverage reports.

• Haddock links to prebuilt libraries.

• Various improvements to reduce header size limits and command line
  argument length, in order to better support macOS and Windows.

Added

• haskell_cabal_library/haskell_cabal_binary.
  See #879,
  #898 and
  #904.
• stack_snapshot.
  See #887 (name
  changed to stack_snapshot after this PR).
  See also #1011.
• tools arguments for stack and cabal rules.
  See #907.
  They can be arbitrary tools,
  see #987.
• tools attribute to core haskell_* rules. This attribute can be
  used to expose GHC preprocessors.
  See #911.
• Static GHC RTS can be specified in the toolchain.
  See #970.
• runfiles library: manifest file support (for Windows).
  See #992.
• Prototype implementation of bazel worker mode (not production-ready
  yet).
  See #1024
  and #1055

Changed

• The haskell_toolchain macro now no longer adds a toolchain
  definition. You must now define yourself a haskell_toolchain and
  a toolchain separately. This should be a mostly transparent
  change, because nearly no one uses these functions directly. They
  are normally only used transitively via
  haskell_register_toolchains and related functions.
  See #843.

• The haskell/haskell.bzl entrypoint is deprecated. use
  haskell/defs.bzl instead.

• The haskell_repositories() macro is deprecated. Use
  rules_haskell_dependencies() from haskell/repositories.bzl
  instead.

• The haskell_register_toolchains() macro is deprecated. Use
  rules_haskell_toolchains() from haskell/repositories.bzl
  instead.

• The exports attribute’s semantics are changed:

  ‘A list of other haskell libraries that will be transparently added
  as a dependency to every downstream rule.’

  The original exports is available under the new name
  reexported_modules.
  See #1008.

• @ is allowed in Haskell binary names.

• haskell_library may be empty (no files in srcs).
  See #1035.

Removed

• The haskell_lint rule has been removed. It should have been
  designed as a test rule and it should have had a different name. The
  rule isn't even necessary for its current purpose: it's more
  convenient to turn on compiler warnings globally in the toolchain
  definition.

• The cc_haskell_import and haskell_cc_import rules have been removed.
  These rules were redundant since Haskell rules can directly interact with C
  rules. Use the following patterns instead.

  # To import Haskell from C.
  haskell_library(name = "haskell-lib", ...)
  cc_library(name = "cc-lib", deps = [":haskell-lib"], ...)
  
  # To import C from Haskell.
  cc_library(name = "cc-lib", ...)
  haskell_library(name = "haskell-lib", deps = [":cc-lib"], ...)
  
  # To import a pre-built library.
  cc_library(name = "so-lib", srcs = glob(["libxyz.so*", "libxyz.dylib", "libxyz.a", "libxyz.dll"]))
  haskell_library(name = "haskell-lib", deps = [":so-lib"], ...)
  

Fixed

• haskell_register_ghc_nixpkgs: Forward all arguments to wrapped
  rules. See #886.
  Also support repository argument and nixopts.
• Haddock links to prebuilt libraries.
  See #928
  and #934.
• Documentation for GHC plugin targets is now included in
  the API documentation.
• The Multi-REPL recognizes haskell_toolchain_library dependencies.
• Various imrovements to linking. See
  #930.
• $(location) expansion for “expression is not a declared
  prerequisite of this rule”.
  See #990.
• Better error if the compiler version doesn’t match the one specified
  in the toolchain.
  See #1014.
• macOS bindists correctly find ar and sed invocation was broken.
  See #1022
  and #1017.
• Allow arbitrary name for haskell_cabal_library. See
  #1034.
• Various fixes for c2hs on Windows
  See #1046
  and #1052.
• :load command in ghci
  See #1046.

Improved

• Profiling mode (--compilation_mode="dbg").
  See #896.
• GHC errors won’t be swallowed anymore.
  See #1050.

Release 0.9.1

Fixed

• Bindists were broken on MacOS.
  See 884.

Release 0.9

Highlights

• The minimum supported Bazel version is now v0.24.

  The version is available from nixpkgs unstable and via
  official releases.

• Initial Windows support

  A non-trivial subset of rules_haskell is now working on Windows.
  See the project tracker
  for finished and ongoing work.

• Improved OSX support

  Due to the mach-o header size limit, we took extra measures to
  make sure generated library paths are as short as possible, so
  linking haskell binaries works even for large dependency graphs.

• Better Bindist support

  The default start script sets up a
  bindist-based project by default.

  rules_nixpkgs is no longer a required dependency of
  rules_haskell (but can still be used as backend).

• Full Haskell–C–Haskell Sandwich

  A haskell_library can be now be used nearly anywhere a
  cc_library can.

  The old cc_haskell_import and haskell_cc_import wrapper rules
  are no longer necessary and have been deprecated.

• Greatly improved REPL support

  A new haskell_repl rule allows to load multiple source targets by
  source, or compiled, as needed. Example usage:

  haskell_repl(
    name = "my-repl",
    # Collect all transitive Haskell dependencies from these targets.
    deps = [
        "//package-a:target-1",
        "//package-b:target-2",
    ],
    # Load targets by source that match these patterns.
    include = [
        "//package-a/...",
        "//packaga-b/...",
        "//common/...",
    ],
    # Don't load targets by source that match these patterns.
    exclude = [
        "//package-a/vendored/...",
    ],
  )
  

• Support for GHC plugins

  Each haskell_* rule now has a plugins attribute. It takes a
  list of bazel targets, which should be haskell_librarys that
  implement the GHC plugin
  specification.

• Initial Code Coverage support

  Measure coverage of your Haskell code. See the “Checking Code
  Coverage”
  section in the manual.

Compatibility Notice

hazel was merged into
rules_haskell, but
we are not yet certain about the exact interface we want to expose.
hazel is therefore not included in this release, and we can’t
guarantee the original, unmerged version is compatible with this
release. If you depend on hazel, please use a recent master commit
of rules_haskell.

Changed

• haskell_register_ghc_bindists is no longer re-exported from
  //haskell/haskell.bzl.
  You must now load that macro from //haskell:nixpkgs.bzl.

• rules_nixpkgs is no longer a dependency of rules_haskell.

• haskell_import has been renamed to haskell_toolchain_library.
  This is a substantial breaking change. But adapting to it should be
  as simple as

  sed -i 's/^haskell_import/haskell_toolchain_library/' **/BUILD{,.bazel}
  sed -i 's/"haskell_import"/"haskell_toolchain_library"/' **/BUILD{,.bazel}
  

  See #843.

• haskell_toolchain’s tools attribute is now a list of labels.
  Earlier entries take precendence. To migrate, add [] around your
  argument.
  See #854.

• The default outputs of haskell_library are now the static and/or
  shared library files, not the package database config and cache
  files.

Added

• haskell_repl rule that constructs a ghci wrapper that loads
  multiple targets by source.
  See #736.
• plugins attribute to haskell_* rules to load GHC plugins.
  See #799.
• The HaskellInfo and HaskellLibraryInfo providers are now
  exported and thus accessible by downstream rules.
  See #844.
• Generate version macros for preprocessors (c2hs, hsc2hs).
  See #847.
• bindist_toolchain rule gets haddock_flags and repl_ghci_args
  attributes.
• @repl targets write json file with build information, usable by
  IDE tools.
  See #695.

Deprecated

• haskell_cc_import; use cc_library instead.
  See #831.
• cc_haskell_import; just use haskell_library like a cc_library.
  See #831.

Fixed

• Support protobuf roots in haskell_proto_library.
  See #722.
• Made GHC bindist relocatable on *nix.
  See #853.
• Various other fixes

Release 0.8

[0.8] - 2019-01-28

• The minimum supported Bazel version is now v0.21.

Added

• haskell_register_toolchains, haskell_register_ghc_bindists and
  haskell_register_ghc_nixpkgs to register multiple toolchains for
  multiple platforms at once. Toolchains from binary distributions can
  now coexist with toolchains from Nixpkgs, even on the same platform.
  On nixpkgs you need to provide a toolchain. See
  the README for instructions.
  See #597
  and #610.
• Instructions on how to reference a local checkout of rules_haskell.
• rules_haskell is forward-compatible with the next breaking changes
  in bazel versions, via the --all_incompatible_changes flag.
  See #613.

Removed

• The generate_so attribute of haskell_binary and haskell_test
  has been completely superseded by linkstatic in the last release
  and became a no-op, so it is removed.
• The main_file attribute of haskell_binary and haskell_test
  had been deprecated because it was a no-op, so it is removed.
• The prebuilt_dependencies attribute of all haskell rules
  had been deprecated two versions ago and is removed.
  Use haskell_import instead (see docs for usage).
• The extra_binaries field is now no longer supported.

Changed

• ghc_bindist now requires a target argument. Use
  haskell_register_ghc_nixpkgs to call ghc_bindist once per known
  target.
  See #610.
• ghc_bindist now registers itself as a toolchain. We no longer
  require a separate toolchain definition and registration in addition
  to ghc_bindist.
  See #610.
• c2hs support is now provided in a separate toolchain called
  c2hs_toolchain, rather than an optional extra to the
  haskell_toolchain.
  See #590.
• Rename bindist arch names so they are the same as in
  rules_go/nodejs.

Fixed

• Prevent duplicate installs of bazel_skylib
  See #536.
• Test suite now executes all binaries, various runtime errors were
  uncovered.
  See #551.
• Repl targets that have indirect cc_library dependencies.
  See #576.
• linkstatic for haskell binaries that have an indirect dependency
  on a prebuilt haskell package.
  See #569.
• … and an indirect dependency on a C library.
  See #567.
• Prefer linking agains static C libraries with linkstatic.
  See #587.
• Haddock flags take precedence over GHC compiler flags.
  See #572.
• User-defined GHC flags now override default flags.
  See #607.
• Dynamic transitive C(++) libraries work.
  See #627.

Release 0.7

[0.7] - 2018-12-24

Added

• Support for Bazel 0.20.0. This is now also the lower bound for the supported version.
• Supported reexported modules, via the new exports attribute. See #357.
• Support linkstatic attribute, for building mostly static binaries. This is now the default for binaries, to match the C/C++ rules defaults. See #378.
• It is now possible to set default Haddock flags in the toolchain definition. See #425.
• Support wrapping Haskell libraries as shared objects callable from Python. See #370.

Changed

• REPL targets have changed name. If you have a library target foo, then the corresponding REPL target is now called foo@repl. It was previously called foo-repl. The old name is still supported but is deprecated.
• Don't set a default version number anymore in libraries and binaries. Version numbers, and CPP version macros, are now only used for packages imported from Hackage. Don't use them otherwise. See #386, #414 and #446.
• On macOS, we use ar for linking, not Libtool. See #392.
• The runfiles Haskell library has been broken out into a Cabal library and published on Hackage.

Fixed

• Make REPL force building of dependencies. See #363.
• Don’t crash on inputs missing .haddock interface files. See #362
• Fix handling of non-unique package names. See #403.

Release 0.6

[0.6] - 2018-07-21

Added

• Protocol buffers integration using proto-lens. See
  #239.

• strip_include_prefix attribute to the haskell_cc_import rule. See
  #241.

• Support for c2hs files. See
  #351.

• The extra_srcs attribute that allows to list non-Haskell source files
  that should be visible during compilation and linking (usually useful with
  TH). See #292.

• The extra_binaries attribute to the haskell_toolchain rule. See
  #282.

• A Haskell library for looking up runfiles. See
  #302.

• A separate toolchain for doctest—haskell_doctest_toolchain. See
  #310.

• The compiler_flags attribute to the haskell_toolchain rule allowing to
  specify default compiler flags. See
  #315.

• The ability to set locale to be used during compilation by adding the
  locale and locale_archive attributes to haskell_toolchain. See
  #328.

• Proper support for profiling. See
  #332.

• The repl_ghci_args attribute to the haskell_toolchain rule. See
  #334.

• The haskell_import rule allowing us to make specifying dependencies more
  uniform and to deprecate the prebuilt_dependencies attribute. See
  #337.

Fixed

• Template Haskell linking against cc_library. See
  #218.

• Linking issues on MacOS. See
  #221.

• GHC packages that correspond to targets with the same name but in
  different Bazel packages no longer clash. See
  #219.

• Build breakage on MacOS when XCode is not installed. See
  #223.

• Bug preventing Haddock generation because of missing dynamic shared
  libraries when targets have TH in them. See
  #226.

• Hyperlinks between targets contained in different Bazel packages
  (Haddocks). See #231.

• Generated source files do not cause issues now. See
  #211.

• data attributes now allow files in them. See
  #236.

• Bug when headers and hsc2hs-produced files were not visible to Haddock.
  See #254.

• Bug preventing using genrule-produced headers via haskell_cc_import. See
  #268.

• Bug that allowed us avoid specifying certain prebuilt_dependencies if
  they were already specified for transitive dependencies. See
  #286.

• Bug that was making modules generated from .hsc and .chs files and
  generated modules in general not available in the REPLs. See
  #323.

Changed

• Added -Wnoncanonical-monad-instances to default warnings in
  haskell_lint.

• How REPLs work. Now there is an optional output per binary/library. Its
  name is the name of target with -repl added. Users can then build and
  run such a REPL for any defined target. See
  #220 and
  #225.

• The haskell_doc rule now produces self-contained documentation bundle
  with unified index. See
  #249.

• haskell_lint now only lints direct dependencies. See
  #293.

• haskell_doctest has been re-designed. It's now a normal rule that works
  only on direct dependencies and allows to specify modules which should be
  tested, pass custom flags to doctest executable. See
  #342.

• The prebuilt_dependencies attribute of haskell_binary and
  haskell_library has been deprecated. See
  #355.

Release 0.5

[0.5] - 2018-04-15

Added

• Support for MacOS, courtesy of Judah Jacobson. See
  #165.

• Support for data attributes in haskell_binary and haskell_library
  rules. See #167.

• Output on building of GHC bindists so it's clearer what went wrong in case
  of a failure.

• haskell_repl rule allowing to interact with GHCi. See
  #82.

• Support for GHC 8.4.1 bindist. See
  #175.

• haskell_lint rule. See
  #181.

• haskell_doctest rule. See
  #194.

Changed

• Improved hermeticity of builds. See
  #180.

• cc_haskell_import now works with haskell_binary targets as well. See
  #179.

Release 0.4

[0.4] - 2018-02-27

Added

• hidden_modules attribute of the haskell_library rule. This allows to
  selectively hide modules in a library. See
  #152.

Fixed

• Test executables now find shared libraries correctly at runtime. See
  #151.

• Building of certain modules does not fail with the “file name does not
  match module name” message anymore. See
  #139.

• Linking issues that resulted in unresolved symbols due to incorrect order
  in which static libraries are passed to linker are not resolved. See
  #140.

• The “grep not found” error is fixed. See
  #141.

• System-level shared libraries introduced by haskell_cc_import are now
  found correctly during compilation. See
  #142.