back port haddock cpp fixes to 1.18 #2010
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Dropping this support is unlikely to be a problem in practice. Debian oldstable is currently on version 2.6.0 of Haddock, for example. This change enables future code simplification. Currently we preprocess both Haskell files requiring the CPP and Literate Haskell files; newer versions of Haddock can handle these natively. Fixes issue haskell#1718. Conflicts: Cabal/Distribution/Simple/Haddock.hs Cabal/Distribution/Simple/PreProcess.hs Cabal/Distribution/Simple/Setup.hs
This is a code simplification on our end. Thanks to Mikhail Glushenkov for the suggestion. Conflicts: Cabal/Distribution/Simple/Haddock.hs
Until recently we supported ancient versions of Haddock, pre v2.0. To
support the CPP extension with such versions, cabal had to invoke the
CPP before invoking Haddock on the output. For simplicity cabal would
invoke the CPP on all Haskell files, if any Haskell file required CPP.
However, invoking CPP on a file which does not require it can cause
build failures.
Haddock v2.0+ supports the CPP via GHC, and even automatically
preprocesses any file with the {-# LANGUAGE CPP #-} pragma. Hence we
simply need only tell Haddock to enable the CPP when the CPP is a
package level default extension.
Fixes issue haskell#1808.
|
I will make a release this afternoon (CET). |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
These five commits remove support for Haddock pre-2.0, and do so to fix a problem where Cabal, if CPP was listed as an Extension, would pre-process the file before handing to haddock, which would cause ghc to pre-process file as well.
This double pre-processing was clearly wrong (possibly leading to wrong line numbers in haddock messages), but more importantly failed when the system compiler was clang. This is because c preprocessing is not idempotent, and under clang, the changes resulted in syntax errors.