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Branch: master

Deduplicate one-shot/make compile paths.

We had a duplicate copy of the code for --make and for -c
which was a pain.  The call graph looked something like this:

    compileOne -> genericHscCompileGetFrontendResult -> genericHscFrontend
                                   hscCompileOneShot ---^

with genericHscCompileGetFrontendResult and hscCompileOneShot
duplicating logic for deciding whether or not recompilation
was needed.

This patchset fixes it, so now everything goes through this call-chain:

    compileOne (--make entry point)
        Calls hscIncrementCompile, invokes the pipeline to do codegen
        and sets up linkables.
    hscIncrementalCompile (-c entry point)
        Calls hscIncrementalFrontend, and then simplifying,
        desugaring, and writing out the interface.
        Performs recompilation avoidance, if recompilation needed,
        does parses typechecking.

I also cleaned up some of the MergeBoot nonsense by introducing
a FrontendResult type.

NB: this BREAKS #8101 again, because I can't unconditionally desugar
due to Haddock barfing on lint, see #10600

Signed-off-by: Edward Z. Yang <>

Test Plan: validate

Reviewers: simonpj, bgamari, simonmar, austin

Subscribers: thomie

Differential Revision:
latest commit 427f8a15c3
@ezyang ezyang authored
Failed to load latest commit information.
bindisttest Follow-up to 32f41c7
compiler Deduplicate one-shot/make compile paths.
distrib Build system: delete unused distrib/Makefile
docs Fill in associated type defaults with DeriveAnyClass
driver Build system: simplify
ghc Prevent GHC from silently dying when preprocessor is not found
includes Fix signature of atomic builtins
libffi-tarballs @ b6658e5 Update libffi-tarballs submodule to libffi 3.1 (re #8701)
libffi Build system: delete half-baked Cygwin support
libraries Make GHC generics capable of handling unboxed types
mk Build system: don't create mk/
nofib @ a599585 Update nofib submodule again
rts Make Windows linker more robust to unknown sections
rules Move user's guide to ReStructuredText
testsuite Deduplicate one-shot/make compile paths.
utils Prevent GHC from silently dying when preprocessor is not found
.arcconfig Fix .arcconfig
.arclint Cabal submodule update: hole support and tests.
.gitignore Build system: don't create mk/
.gitmodules Delete old-{time,locale} and haskell{98,2010}
.mailmap Update .mailmap [skip ci]
.travis.yml Move user's guide to ReStructuredText
ANNOUNCE Globally replace "" with "" Make configure error out on missing ghc-tarballs on Windows Move user's guide to ReStructuredText
LICENSE Reorganisation of the source tree Build system: implement `make install-strip` (#1851)
Makefile Always run explicitly requested ways (extra_ways) for fast runs. Move user's guide to ReStructuredText
Vagrantfile vagrant: move files around
aclocal.m4 Move user's guide to ReStructuredText
boot Build system: detect when user cloned from GitHub
config.guess Update config.{guess,sub} to GNU automake 1.14.1
config.sub Update config.{guess,sub} to GNU automake 1.14.1 Build system: add mk/ Build system: don't create mk/
install-sh Update aux files `config.{guess,sub}` and `install-sh`
packages Remove all references to sync-all LlvmCodeGen cross-compiling fixes (#9895)
validate Build system: don't create mk/

The Glasgow Haskell Compiler

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