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author | Ben Gamari <bgamari.foss@gmail.com> | 2015-10-30 20:22:42 +0100 |
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committer | Ben Gamari <ben@smart-cactus.org> | 2015-10-30 20:22:44 +0100 |
commit | 91c6b1f54aea658b0056caec45655475897f1972 (patch) | |
tree | aeb80a04e102e51dfd41343d4f697baf34c95739 /testsuite/tests/roles/should_compile/Roles3.stderr | |
parent | 59e728bc0b47116e3c9a8b21b14dc3198531b9a9 (diff) | |
download | haskell-91c6b1f54aea658b0056caec45655475897f1972.tar.gz |
Generate Typeable info at definition sites
This is the second attempt at merging D757.
This patch implements the idea floated in Trac #9858, namely that we
should generate type-representation information at the data type
declaration site, rather than when solving a Typeable constraint.
However, this turned out quite a bit harder than I expected. I still
think it's the right thing to do, and it's done now, but it was quite
a struggle.
See particularly
* Note [Grand plan for Typeable] in TcTypeable (which is a new module)
* Note [The overall promotion story] in DataCon (clarifies existing
stuff)
The most painful bit was that to generate Typeable instances (ie
TyConRepName bindings) for every TyCon is tricky for types in ghc-prim
etc:
* We need to have enough data types around to *define* a TyCon
* Many of these types are wired-in
Also, to minimise the code generated for each data type, I wanted to
generate pure data, not CAFs with unpackCString# stuff floating about.
Performance
~~~~~~~~~~~
Three perf/compiler tests start to allocate quite a bit more. This isn't
surprising, because they all allocate zillions of data types, with
practically no other code, esp. T1969
* T1969: GHC allocates 19% more
* T4801: GHC allocates 13% more
* T5321FD: GHC allocates 13% more
* T9675: GHC allocates 11% more
* T783: GHC allocates 11% more
* T5642: GHC allocates 10% more
I'm treating this as acceptable. The payoff comes in Typeable-heavy
code.
Remaining to do
~~~~~~~~~~~~~~~
* I think that "TyCon" and "Module" are over-generic names to use for
the runtime type representations used in GHC.Typeable. Better might
be
"TrTyCon" and "TrModule". But I have not yet done this
* Add more info the the "TyCon" e.g. source location where it was
defined
* Use the new "Module" type to help with Trac Trac #10068
* It would be possible to generate TyConRepName (ie Typeable
instances) selectively rather than all the time. We'd need to persist
the information in interface files. Lacking a motivating reason I
have
not done this, but it would not be difficult.
Refactoring
~~~~~~~~~~~
As is so often the case, I ended up refactoring more than I intended.
In particular
* In TyCon, a type *family* (whether type or data) is repesented by a
FamilyTyCon
* a algebraic data type (including data/newtype instances) is
represented by AlgTyCon This wasn't true before; a data family
was represented as an AlgTyCon. There are some corresponding
changes in IfaceSyn.
* Also get rid of the (unhelpfully named) tyConParent.
* In TyCon define 'Promoted', isomorphic to Maybe, used when things are
optionally promoted; and use it elsewhere in GHC.
* Cleanup handling of knownKeyNames
* Each TyCon, including promoted TyCons, contains its TyConRepName, if
it has one. This is, in effect, the name of its Typeable instance.
Updates haddock submodule
Test Plan: Let Harbormaster validate
Reviewers: austin, hvr, goldfire
Subscribers: goldfire, thomie
Differential Revision: https://phabricator.haskell.org/D1404
GHC Trac Issues: #9858
Diffstat (limited to 'testsuite/tests/roles/should_compile/Roles3.stderr')
-rw-r--r-- | testsuite/tests/roles/should_compile/Roles3.stderr | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/testsuite/tests/roles/should_compile/Roles3.stderr b/testsuite/tests/roles/should_compile/Roles3.stderr index 6f25b63691..483b349907 100644 --- a/testsuite/tests/roles/should_compile/Roles3.stderr +++ b/testsuite/tests/roles/should_compile/Roles3.stderr @@ -26,4 +26,29 @@ Dependent packages: [base-4.8.2.0, ghc-prim-0.4.0.0, integer-gmp-1.0.0.0] ==================== Typechecker ==================== +Roles3.$tcC4 + = TyCon + 12861862461396457184## + 6389612623460961504## + Roles3.$trModule + (TrNameS "C4"#) +Roles3.$tcC3 + = TyCon + 5998139369941479154## + 6816352641934636458## + Roles3.$trModule + (TrNameS "C3"#) +Roles3.$tcC2 + = TyCon + 8833962732139387711## + 7891126688522429937## + Roles3.$trModule + (TrNameS "C2"#) +Roles3.$tcC1 + = TyCon + 16242970448469140073## + 10229725431456576413## + Roles3.$trModule + (TrNameS "C1"#) +Roles3.$trModule = Module (TrNameS "main"#) (TrNameS "Roles3"#) |