| Commit message (Collapse) | Author | Age | Files | Lines |
|---|
| ... | |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This implements `DVarSet`, a deterministic set of Vars, with an
interface very similar to `VarSet` with a couple of functions missing.
I will need this in changes that follow, one of them will be about
changing the type of the set of Vars that `RuleInfo` holds to make the
free variable computation deterministic.
Test Plan:
./validate
I can add new tests if anyone wants me to.
Reviewers: simonpj, simonmar, austin, bgamari
Reviewed By: simonmar, bgamari
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D1487
GHC Trac Issues: #4012
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This patch tackles two issues:
1) GHC stores a "link info" string into a ELF section. Initially a
section with type "note" was used but GHC didn't follow the ELF
specification which specifies a record-based format for these sections.
With D1375 we switched to a "progbits" section type for which there
isn't any format constraint. This is an issue for D1242 which use GCC's
--gc-sections which collects "unused" sections, such as our section
containing link info... In this patch, we fall back to a section with
type "note" but we respect the specified format.
2) Reading back the ELF section was done by parsing the result of a
call to "readelf". Calling readelf is problematic because the program
may not be available or it may be renamed on some platforms (see
D1326). Moreover we have no garanty that its output layout will stay
the same in future releases of readelf. Finally we would need to fix
the parsing to support "note" sections because of 1. Instead, this
patch proposes to use Data.Binary.Get to directly read the "link info"
note into its section. ELF has a specification, hence it should work on
every conforming platform.
This patch "reverts" D1375, hence it supersedes D1432. It makes D1326
not necessary anymore.
Test Plan:
- recomp011 should pass (test that relinking is avoided when both "link
info" match)
- we should add a test for ELF objects with more than 0xff00 sections
=> added test "recomp015"
- we should check that GAS generates 32-bit words with .int on every
supported platform using ELF (or find a place where this is
documented). harbomaster and I (@hsyl20) only tested on x86-64. On
platforms where it is not true, it should make recomp011 fail. =>
tested to work on Linux/amd64, Solaris/i386 and OpenBSD/amd64
Reviewers: olsner, ony, thomie, kgardas, austin, bgamari
Reviewed By: thomie, bgamari
Subscribers: kgardas, rwbarton, thomie
Differential Revision: https://phabricator.haskell.org/D1381
GHC Trac Issues: #10974, #11022
|
| |
|
|
|
| |
We already used a process-1.4 snapshot with non-bumped version,
so this commit is mostly a `.cabal` file upper-bound relaxation change.
|
| |
|
|
|
|
|
|
|
|
| |
This is needed to prepare for #11026 as this update
relaxes the upper bounds on `base` to allow for `base-4.9.0.0`
This also needs to relax a few upper bounds on process in some cabal files
(there will be another process submodule update soon, as a major
version bump of process' version is still pending)
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
When generating dictionary let binds in dsTcEvBinds we may
end up generating them in arbitrary order according to Unique order.
Consider:
```
let $dEq = GHC.Classes.$fEqInt in
let $$dNum = GHC.Num.$fNumInt in ...
```
vs
```
let $dNum = GHC.Num.$fNumInt in
let $dEq = GHC.Classes.$fEqInt in ...
```
The way this change fixes it is by using `UniqDFM` - a type of
deterministic finite maps of things keyed on `Unique`s. This way when
you pull out evidence variables corresponding to type-class dictionaries
they are in deterministic order.
Currently it's the order of insertion and the way it's implemented is by
tagging the values with the time of insertion.
Test Plan:
I've added a new test case to reproduce the issue.
./validate
Reviewers: ezyang, simonmar, austin, simonpj, bgamari
Reviewed By: simonmar, simonpj, bgamari
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D1396
GHC Trac Issues: #4012
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
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
|
| |
|
|
|
|
|
|
| |
This reverts commit bef2f03e4d56d88a7e9752a7afd6a0a35616da6c.
This merge was botched
Also reverts haddock submodule.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
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
* T3294: GHC allocates 110% more (filed #11030 to track this)
* T1969: GHC allocates 30% more
* T4801: GHC allocates 14% more
* T5321FD: GHC allocates 13% more
* T783: GHC allocates 12% more
* T9675: GHC allocates 12% more
* T5642: GHC allocates 10% more
* T9961: GHC allocates 6% more
* T9203: Program allocates 54% less
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.
Requires update of the haddock submodule.
Differential Revision: https://phabricator.haskell.org/D757
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This implements DuplicateRecordFields, the first part of the
OverloadedRecordFields extension, as described at
https://ghc.haskell.org/trac/ghc/wiki/Records/OverloadedRecordFields/DuplicateRecordFields
This includes fairly wide-ranging changes in order to allow multiple
records within the same module to use the same field names. Note that
it does *not* allow record selector functions to be used if they are
ambiguous, and it does not have any form of type-based disambiguation
for selectors (but it does for updates). Subsequent parts will make
overloading selectors possible using orthogonal extensions, as
described on the wiki pages. This part touches quite a lot of the
codebase, and requires changes to several GHC API datatypes in order
to distinguish between field labels (which may be overloaded) and
selector function names (which are always unique).
The Haddock submodule has been adapted to compile with the GHC API
changes, but it will need further work to properly support modules
that use the DuplicateRecordFields extension.
Test Plan: New tests added in testsuite/tests/overloadedrecflds; these
will be extended once the other parts are implemented.
Reviewers: goldfire, bgamari, simonpj, austin
Subscribers: sjcjoosten, haggholm, mpickering, bgamari, tibbe, thomie,
goldfire
Differential Revision: https://phabricator.haskell.org/D761
|
| |
|
|
|
|
| |
Comes with Haddock submodule update.
Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Trac #10796 exposes a way to make `template-haskell`'s `dataToQa` function
freak out if using a `Data` instance that produces a `Constr` (by means of
`toConstr`) using a function name instead of a data constructor name. While
such `Data` instances are somewhat questionable, they are nevertheless present
in popular libraries (e.g., `containers`), so we can at least make `dataToQa`
aware of their existence.
In order to properly distinguish strings which represent variables (as opposed
to data constructors), it was necessary to move functionality from `Lexeme` (in
`ghc`) to `GHC.Lexeme` in a new `ghc-boot` library (which was previously named
`bin-package-db`).
Reviewed By: goldfire, thomie
Differential Revision: https://phabricator.haskell.org/D1313
GHC Trac Issues: #10796
|
| |
|
|
| |
Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
|
| |
|
|
|
|
| |
We require ghc-7.8 to build HEAD (ghc-7.11).
Differential Revision: https://phabricator.haskell.org/D1165
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This reverses some of the work done in #1405, and goes back to the
assumption that the bootstrap compiler understands GHC-haskell.
In particular:
* use MagicHash instead of _ILIT and _CLIT
* pattern matching on I# if possible, instead of using iUnbox
unnecessarily
* use Int#/Char#/Addr# instead of the following type synonyms:
- type FastInt = Int#
- type FastChar = Char#
- type FastPtr a = Addr#
* inline the following functions:
- iBox = I#
- cBox = C#
- fastChr = chr#
- fastOrd = ord#
- eqFastChar = eqChar#
- shiftLFastInt = uncheckedIShiftL#
- shiftR_FastInt = uncheckedIShiftRL#
- shiftRLFastInt = uncheckedIShiftRL#
* delete the following unused functions:
- minFastInt
- maxFastInt
- uncheckedIShiftRA#
- castFastPtr
- panicDocFastInt and pprPanicFastInt
* rename panicFastInt back to panic#
These functions remain, since they actually do something:
* iUnbox
* bitAndFastInt
* bitOrFastInt
Test Plan: validate
Reviewers: austin, bgamari
Subscribers: rwbarton
Differential Revision: https://phabricator.haskell.org/D1141
GHC Trac Issues: #1405
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This reverses some of the work done in Trac #1405, and assumes GHC is
smart enough to do its own unboxing of booleans now.
I would like to do some more performance measurements, but the code
changes can be reviewed already.
Test Plan:
With a perf build:
./inplace/bin/ghc-stage2 nofib/spectral/simple/Main.hs -fforce-recomp
+RTS -t --machine-readable
before:
```
[("bytes allocated", "1300744864")
,("num_GCs", "302")
,("average_bytes_used", "8811118")
,("max_bytes_used", "24477464")
,("num_byte_usage_samples", "9")
,("peak_megabytes_allocated", "64")
,("init_cpu_seconds", "0.001")
,("init_wall_seconds", "0.001")
,("mutator_cpu_seconds", "2.833")
,("mutator_wall_seconds", "4.283")
,("GC_cpu_seconds", "0.960")
,("GC_wall_seconds", "0.961")
]
```
after:
```
[("bytes allocated", "1301088064")
,("num_GCs", "310")
,("average_bytes_used", "8820253")
,("max_bytes_used", "24539904")
,("num_byte_usage_samples", "9")
,("peak_megabytes_allocated", "64")
,("init_cpu_seconds", "0.001")
,("init_wall_seconds", "0.001")
,("mutator_cpu_seconds", "2.876")
,("mutator_wall_seconds", "4.474")
,("GC_cpu_seconds", "0.965")
,("GC_wall_seconds", "0.979")
]
```
CPU time seems to be up a bit, but I'm not sure. Unfortunately CPU time
measurements are rather noisy.
Reviewers: austin, bgamari, rwbarton
Subscribers: nomeata
Differential Revision: https://phabricator.haskell.org/D1143
GHC Trac Issues: #1405
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
A library name is a package name, package version, and hash of the
version names of all textual dependencies (i.e. packages which were included.) A library
name is a coarse approximation of installed package IDs, which are suitable for
inclusion in package keys (you don't want to put an IPID in a package key, since
it means the key will change any time the source changes.)
- We define ShPackageKey, which is the semantic object which
is hashed into a PackageKey. You can use 'newPackageKey'
to hash a ShPackageKey to a PackageKey
- Given a PackageKey, we can lookup its ShPackageKey with
'lookupPackageKey'. The way we can do this is by consulting
the 'pkgKeyCache', which records a reverse mapping from
every hash to the ShPackageKey. This means that if you
load in PackageKeys from external sources (e.g. interface
files), you also need to load in a mapping of PackageKeys
to their ShPackageKeys so we can populate the cache.
- We define a 'LibraryName' which encapsulates the full
depenency resolution that Cabal may have selected; this
is opaque to GHC but can be used to distinguish different
versions of a package.
- Definite packages don't have an interesting PackageKey,
so we rely on Cabal to pass them to us.
- We can pretty-print package keys while displaying the
instantiation, but it's not wired up to anything (e.g.
the Outputable instance of PackageKey).
Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
Test Plan: validate
Reviewers: austin, bgamari
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D1056
GHC Trac Issues: #10566
|
| |
|
|
|
| |
This allows PprCore to use these functions. It will soon do so to enable
CoreLint to output size annotations on top-level bindings.
|
| |
|
|
|
| |
These seem to sit near the top of the import graph and have been causing
import cycles.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This commit renames the Size module in the native code generator to
Format, as proposed by a todo, as well as adjusting parameter names in
other modules that use it.
Test Plan: validate
Reviewers: austin, simonmar, bgamari
Reviewed By: simonmar, bgamari
Subscribers: bgamari, simonmar, thomie
Projects: #ghc
Differential Revision: https://phabricator.haskell.org/D865
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Make tuple constraints be handled by a perfectly ordinary
type class, with the component constraints being the
superclasses:
class (c1, c2) => (c2, c2)
This change was provoked by
#10359 inability to re-use a given tuple
constraint as a whole
#9858 confusion between term tuples
and constraint tuples
but it's generally a very nice simplification. We get rid of
- In Type, the TuplePred constructor of PredTree,
and all the code that dealt with TuplePreds
- In TcEvidence, the constructors EvTupleMk, EvTupleSel
See Note [How tuples work] in TysWiredIn.
Of course, nothing is ever entirely simple. This one
proved quite fiddly.
- I did quite a bit of renaming, which makes this patch
touch a lot of modules. In partiuclar tupleCon -> tupleDataCon.
- I made constraint tuples known-key rather than wired-in.
This is different to boxed/unboxed tuples, but it proved
awkward to have all the superclass selectors wired-in.
Easier just to use the standard mechanims.
- While I was fiddling with known-key names, I split the TH Name
definitions out of DsMeta into a new module THNames. That meant
that the known-key names can all be gathered in PrelInfo, without
causing module loops.
- I found that the parser was parsing an import item like
T( .. )
as a *data constructor* T, and then using setRdrNameSpace to
fix it. Stupid! So I changed the parser to parse a *type
constructor* T, which means less use of setRdrNameSpace.
I also improved setRdrNameSpace to behave better on Exact Names.
Largely on priciple; I don't think it matters a lot.
- When compiling a data type declaration for a wired-in thing like
tuples (,), or lists, we don't really need to look at the
declaration. We have the wired-in thing! And not doing so avoids
having to line up the uniques for data constructor workers etc.
See Note [Declarations for wired-in things]
- I found that FunDeps.oclose wasn't taking superclasses into
account; easily fixed.
- Some error message refactoring for invalid constraints in TcValidity
- Haddock needs to absorb the change too; so there is a submodule update
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This reverts multiple commits from Simon:
- 04a484eafc9eb9f8774b4bdd41a5dc6c9f640daf Test Trac #10359
- a9ccd37add8315e061c02e5bf26c08f05fad9ac9 Test Trac #10403
- c0aae6f699cbd222d826d0b8d78d6cb3f682079e Test Trac #10248
- eb6ca851f553262efe0824b8dcbe64952de4963d Make the "matchable-given" check happen first
- ca173aa30467a0b1023682d573fcd94244d85c50 Add a case to checkValidTyCon
- 51cbad15f86fca1d1b0e777199eb1079a1b64d74 Update haddock submodule
- 6e1174da5b8e0b296f5bfc8b39904300d04eb5b7 Separate transCloVarSet from fixVarSet
- a8493e03b89f3b3bfcdb6005795de050501f5c29 Fix imports in HscMain (stage2)
- a154944bf07b2e13175519bafebd5a03926bf105 Two wibbles to fix the build
- 5910a1bc8142b4e56a19abea104263d7bb5c5d3f Change in capitalisation of error msg
- 130e93aab220bdf14d08028771f83df210da340b Refactor tuple constraints
- 8da785d59f5989b9a9df06386d5bd13f65435bc0 Delete commented-out line
These break the build by causing Haddock to fail mysteriously when
trying to examine GHC.Prim it seems.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Make tuple constraints be handled by a perfectly ordinary
type class, with the component constraints being the
superclasses:
class (c1, c2) => (c2, c2)
This change was provoked by
#10359 inability to re-use a given tuple
constraint as a whole
#9858 confusion between term tuples
and constraint tuples
but it's generally a very nice simplification. We get rid of
- In Type, the TuplePred constructor of PredTree,
and all the code that dealt with TuplePreds
- In TcEvidence, the constructors EvTupleMk, EvTupleSel
See Note [How tuples work] in TysWiredIn.
Of course, nothing is ever entirely simple. This one
proved quite fiddly.
- I did quite a bit of renaming, which makes this patch
touch a lot of modules. In partiuclar tupleCon -> tupleDataCon.
- I made constraint tuples known-key rather than wired-in.
This is different to boxed/unboxed tuples, but it proved
awkward to have all the superclass selectors wired-in.
Easier just to use the standard mechanims.
- While I was fiddling with known-key names, I split the TH Name
definitions out of DsMeta into a new module THNames. That meant
that the known-key names can all be gathered in PrelInfo, without
causing module loops.
- I found that the parser was parsing an import item like
T( .. )
as a *data constructor* T, and then using setRdrNameSpace to
fix it. Stupid! So I changed the parser to parse a *type
constructor* T, which means less use of setRdrNameSpace.
I also improved setRdrNameSpace to behave better on Exact Names.
Largely on priciple; I don't think it matters a lot.
- When compiling a data type declaration for a wired-in thing like
tuples (,), or lists, we don't really need to look at the
declaration. We have the wired-in thing! And not doing so avoids
having to line up the uniques for data constructor workers etc.
See Note [Declarations for wired-in things]
- I found that FunDeps.oclose wasn't taking superclasses into
account; easily fixed.
- Some error message refactoring for invalid constraints in TcValidity
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Summary:
This commit adds stage 1 support for Template Haskell
quoting, e.g. [| ... expr ... |], which is useful
for authors of quasiquoter libraries that do not actually
need splices. The TemplateHaskell extension now does not
unconditionally fail; it only fails if the renamer encounters
a splice that it can't run.
In order to make sure the referenced data structures
are consistent, template-haskell is now a boot library.
There are some minor BC changes to template-haskell to make it boot
on GHC 7.8.
Note for reviewer: big diff changes are simply code
being moved out of an ifdef; there was no other substantive
change to that code.
Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
Test Plan: validate
Reviewers: simonpj, austin, goldfire
Subscribers: bgamari, thomie
Differential Revision: https://phabricator.haskell.org/D876
GHC Trac Issues: #10382
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Revert "Quick fix: drop base bound on template-haskell."
This reverts commit 3c70ae032e4361b203dfcf22b0a424e8838a5037.
Revert "Always do polymorphic typed quote check, c.f. #10384"
This reverts commit 9a43b2c1f78b3cf684646af64b9b67dc8079f58f.
Revert "RnSplice's staging test should be applied for quotes in stage1."
This reverts commit eb0ed4030374af542c0a459480d32c8d4525e48d.
Revert "Split off quotes/ from th/ for tests that can be done on stage1 compiler."
This reverts commit 21c72e7d38c96ac80d31addf67ae4b3c7a6c3bbb.
Revert "Support stage 1 Template Haskell (non-quasi) quotes, fixes #10382."
This reverts commit 28257cae77023f2ccc4cc1c0cd1fbbd329947a00.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Summary:
This commit adds stage 1 support for Template Haskell
quoting, e.g. [| ... expr ... |], which is useful
for authors of quasiquoter libraries that do not actually
need splices. The TemplateHaskell extension now does not
unconditionally fail; it only fails if the renamer encounters
a splice that it can't run.
In order to make sure the referenced data structures
are consistent, template-haskell is now a boot library.
In the following patches, there are:
- A few extra safety checks which should be enabled
in stage1
- Separation of the th/ testsuite into quotes/ which
can be run on stage1
Note for reviewer: big diff changes are simply code
being moved out of an ifdef; there was no other substantive
change to that code.
Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
Test Plan: validate
Reviewers: simonpj, austin, goldfire
Subscribers: bgamari, thomie
Differential Revision: https://phabricator.haskell.org/D876
GHC Trac Issues: #10382
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This re-implements the code generation for case expressions at the Stg →
Cmm level, both for data type cases as well as for integral literal
cases. (Cases on float are still treated as before).
The goal is to allow for fancier strategies in implementing them, for a
cleaner separation of the strategy from the gritty details of Cmm, and
to run this later than the Common Block Optimization, allowing for one
way to attack #10124. The new module CmmSwitch contains a number of
notes explaining this changes. For example, it creates larger
consecutive jump tables than the previous code, if possible.
nofib shows little significant overall improvement of runtime. The
rather large wobbling comes from changes in the code block order
(see #8082, not much we can do about it). But the decrease in code size
alone makes this worthwhile.
```
Program Size Allocs Runtime Elapsed TotalMem
Min -1.8% 0.0% -6.1% -6.1% -2.9%
Max -0.7% +0.0% +5.6% +5.7% +7.8%
Geometric Mean -1.4% -0.0% -0.3% -0.3% +0.0%
```
Compilation time increases slightly:
```
-1 s.d. ----- -2.0%
+1 s.d. ----- +2.5%
Average ----- +0.3%
```
The test case T783 regresses a lot, but it is the only one exhibiting
any regression. The cause is the changed order of branches in an
if-then-else tree, which makes the hoople data flow analysis traverse
the blocks in a suboptimal order. Reverting that gets rid of this
regression, but has a consistent, if only very small (+0.2%), negative
effect on runtime. So I conclude that this test is an extreme outlier
and no reason to change the code.
Differential Revision: https://phabricator.haskell.org/D720
|
| |
|
|
|
|
| |
This also needs to update a couple of other submodules
to update the upper bound on filepath to allow this major
version bump to 1.4.0.0
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This is where we actually make GHC emit DWARF code. The info section
contains all the general meta information bits as well as an entry for
every block of native code.
Notes:
* We need quite a few new labels in order to properly address starts
and ends of blocks.
* Thanks to Nathan Howell for taking the iniative to get our own Haskell
language ID for DWARF!
(From Phabricator D396)
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
The purpose of the Debug module is to collect all required information
to generate debug information (DWARF etc.) in the back-ends. Our main
data structure is the "debug block", which carries all information we have
about a block of code that is going to get produced.
Notes:
* Debug blocks are arranged into a tree according to tick scopes. This
makes it easier to reason about inheritance rules. Note however that
tick scopes are not guaranteed to form a tree, which requires us to
"copy" ticks to not lose them.
* This is also where we decide what source location we regard as
representing a code block the "best". The heuristic is basically that
we want the most specific source reference that comes from the same file
we are currently compiling. This seems to be the most useful choice in
my experience.
* We are careful to not be too lazy so we don't end up breaking streaming.
Debug data will be kept alive until the end of codegen, after all.
* We change native assembler dumps to happen right away for every Cmm group.
This simplifies the code somewhat and is consistent with how pretty much
all of GHC handles dumps with respect to streamed code.
(From Phabricator D169)
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Summary:
As proposed in [1], this extension introduces a new syntactic form
`static e`, where `e :: a` can be any closed expression. The static form
produces a value of type `StaticPtr a`, which works as a reference that
programs can "dereference" to get the value of `e` back. References are
like `Ptr`s, except that they are stable across invocations of a
program.
The relevant wiki pages are [2, 3], which describe the motivation/ideas
and implementation plan respectively.
[1] Jeff Epstein, Andrew P. Black, and Simon Peyton-Jones. Towards
Haskell in the cloud. SIGPLAN Not., 46(12):118–129, September 2011. ISSN
0362-1340.
[2] https://ghc.haskell.org/trac/ghc/wiki/StaticPointers
[3] https://ghc.haskell.org/trac/ghc/wiki/StaticPointers/ImplementationPlan
Authored-by: Facundo Domínguez <facundo.dominguez@tweag.io>
Authored-by: Mathieu Boespflug <m@tweag.io>
Authored-by: Alexander Vershilov <alexander.vershilov@tweag.io>
Test Plan: `./validate`
Reviewers: hvr, simonmar, simonpj, austin
Reviewed By: simonpj, austin
Subscribers: qnikst, bgamari, mboes, carter, thomie, goldfire
Differential Revision: https://phabricator.haskell.org/D550
GHC Trac Issues: #7015
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Summary:
The final design and discussion is captured at
https://ghc.haskell.org/trac/ghc/wiki/GhcAstAnnotations
This is a proof of concept implementation of a completely
separate annotation structure, populated in the parser,and tied to the
AST by means of a virtual "node-key" comprising the surrounding
SrcSpan and a value derived from the specific constructor used for the
node.
The key parts of the design are the following.
== The Annotations ==
In `hsSyn/ApiAnnotation.hs`
```lang=haskell
type ApiAnns = (Map.Map ApiAnnKey SrcSpan, Map.Map SrcSpan [Located Token])
type ApiAnnKey = (SrcSpan,AnnKeywordId)
-- ---------------------------------------------------------------------
-- | Retrieve an annotation based on the @SrcSpan@ of the annotated AST
-- element, and the known type of the annotation.
getAnnotation :: ApiAnns -> SrcSpan -> AnnKeywordId -> Maybe SrcSpan
getAnnotation (anns,_) span ann = Map.lookup (span,ann) anns
-- |Retrieve the comments allocated to the current @SrcSpan@
getAnnotationComments :: ApiAnns -> SrcSpan -> [Located Token]
getAnnotationComments (_,anns) span =
case Map.lookup span anns of
Just cs -> cs
Nothing -> []
-- | Note: in general the names of these are taken from the
-- corresponding token, unless otherwise noted
data AnnKeywordId
= AnnAs
| AnnBang
| AnnClass
| AnnClose -- ^ } or ] or ) or #) etc
| AnnComma
| AnnDarrow
| AnnData
| AnnDcolon
....
```
== Capturing in the lexer/parser ==
The annotations are captured in the lexer / parser by extending PState to include a field
In `parser/Lexer.x`
```lang=haskell
data PState = PState {
....
annotations :: [(ApiAnnKey,SrcSpan)]
-- Annotations giving the locations of 'noise' tokens in the
-- source, so that users of the GHC API can do source to
-- source conversions.
}
```
The lexer exposes a helper function to add an annotation
```lang=haskell
addAnnotation :: SrcSpan -> Ann -> SrcSpan -> P ()
addAnnotation l a v = P $ \s -> POk s {
annotations = ((AK l a), v) : annotations s
} ()
```
The parser also has some helper functions of the form
```lang=haskell
type MaybeAnn = Maybe (SrcSpan -> P ())
gl = getLoc
gj x = Just (gl x)
ams :: Located a -> [MaybeAnn] -> P (Located a)
ams a@(L l _) bs = (mapM_ (\a -> a l) $ catMaybes bs) >> return a
```
This allows annotations to be captured in the parser by means of
```
ctypedoc :: { LHsType RdrName }
: 'forall' tv_bndrs '.' ctypedoc {% hintExplicitForall (getLoc $1) >>
ams (LL $ mkExplicitHsForAllTy $2 (noLoc []) $4)
[mj AnnForall $1,mj AnnDot $3] }
| context '=>' ctypedoc {% ams (LL $ mkQualifiedHsForAllTy $1 $3)
[mj AnnDarrow $2] }
| ipvar '::' type {% ams (LL (HsIParamTy (unLoc $1) $3))
[mj AnnDcolon $2] }
| typedoc { $1 }
```
== Parse result ==
```lang-haskell
data HsParsedModule = HsParsedModule {
hpm_module :: Located (HsModule RdrName),
hpm_src_files :: [FilePath],
-- ^ extra source files (e.g. from #includes). The lexer collects
-- these from '# <file> <line>' pragmas, which the C preprocessor
-- leaves behind. These files and their timestamps are stored in
-- the .hi file, so that we can force recompilation if any of
-- them change (#3589)
hpm_annotations :: ApiAnns
}
-- | The result of successful parsing.
data ParsedModule =
ParsedModule { pm_mod_summary :: ModSummary
, pm_parsed_source :: ParsedSource
, pm_extra_src_files :: [FilePath]
, pm_annotations :: ApiAnns }
```
This diff depends on D426
Test Plan: sh ./validate
Reviewers: austin, simonpj, Mikolaj
Reviewed By: simonpj, Mikolaj
Subscribers: Mikolaj, goldfire, thomie, carter
Differential Revision: https://phabricator.haskell.org/D438
GHC Trac Issues: #9628
|
| |
|
|
|
| |
This commit also refactors a bunch of lexeme-oriented code into
a new module Lexeme, and includes a submodule update for haddock.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Summary:
See https://ghc.haskell.org/trac/ghc/wiki/Plugins/TypeChecker
This is based on work by Iavor Diatchki and Eric Seidel.
Test Plan: validate
Reviewers: simonpj, austin
Reviewed By: austin
Subscribers: gridaphobe, yav, thomie, carter
Differential Revision: https://phabricator.haskell.org/D489
Conflicts:
docs/users_guide/7.10.1-notes.xml
|
| |
|
|
| |
Signed-off-by: Austin Seipp <austin@well-typed.com>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
The driving change is this:
* The canonical CFunEqCan constraints now have the form
[G] F xis ~ fsk
[W] F xis ~ fmv
where fsk is a flatten-skolem, and fmv is a flatten-meta-variable
Think of them as the name of the type-function application
See Note [The flattening story] in TcFlatten. A flatten-meta-variable
is distinguishable by its MetaInfo of FlatMetaTv
This in turn led to an enormous cascade of other changes, which simplify
and modularise the constraint solver. In particular:
* Basic data types
* I got rid of inert_solved_funeqs altogether. It serves no useful
role that inert_flat_cache does not solve.
* I added wl_implics to the WorkList, as a convenient place to
accumulate newly-emitted implications; see Note [Residual
implications] in TcSMonad.
* I eliminated tcs_ty_binds altogether. These were the bindings
for unification variables that we have now solved by
unification. We kept them in a finite map and did the
side-effecting unification later. But in cannonicalisation we
had to look up in the side-effected mutable tyvars anyway, so
nothing was being gained.
Our original idea was that the solver would be pure, and would
be a no-op if you discarded its results, but this was already
not-true for implications since we update their evidence
bindings in an imperative way. So rather than the uneasy
compromise, it's now clearly imperative!
* I split out the flatten/unflatten code into a new module, TcFlatten
* I simplified and articulated explicitly the (rather hazy) invariants
for the inert substitution inert_eqs. See Note [eqCanRewrite] and
See Note [Applying the inert substitution] in TcFlatten
* Unflattening is now done (by TcFlatten.unflatten) after solveFlats,
before solving nested implications. This turned out to simplify a
lot of code. Previously, unflattening was done as part of zonking, at
the very very end.
* Eager unflattening allowed me to remove the unpleasant ic_fsks
field of an Implication (hurrah)
* Eager unflattening made the TcSimplify.floatEqualities function
much simpler (just float equalities looking like a ~ ty, where a
is an untouchable meta-tyvar).
* Likewise the idea of "pushing wanteds in as givens" could be
completely eliminated.
* I radically simplified the code that determines when there are
'given' equalities, and hence whether we can float 'wanted' equalies
out. See TcSMonad.getNoGivenEqs, and Note [When does an implication
have given equalities?].
This allowed me to get rid of the unpleasant inert_no_eqs flag in InertCans.
* As part of this given-equality stuff, I fixed Trac #9211. See Note
[Let-bound skolems] in TcSMonad
* Orientation of tyvar/tyvar equalities (a ~ b) was partly done during
canonicalisation, but then repeated in the spontaneous-solve stage
(trySpontaneousSolveTwoWay). Now it is done exclusively during
canonicalisation, which keeps all the code in one place. See
Note [Canonical orientation for tyvar/tyvar equality constraints]
in TcCanonical
|
| |
|
|
|
|
|
|
|
|
| |
Summary: now that we can rely on having containers > 0.5.
Reviewers: austin
Subscribers: thomie, carter, ezyang, simonmar
Differential Revision: https://phabricator.haskell.org/D321
|
| |
|
|
|
|
|
| |
This also updates a few submodules to have their upper-bounds on
`time` relaxed to allow `time-1.5`. The only package that can't be
upgraded yet is `Cabal` due to API changes breaking `ghc-cabal`. This
needs to be addressed in a future commit.
|
| |
|
|
|
| |
This left-over is definitely not needed anymore
and was probably missed in 527bcc41630918977c7
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Summary:
This is a first step toward allowing generic traversals of the AST without 'landmines', by removing the `panic`s located throughout `placeHolderType`, `placeHolderKind` & co.
See more on the discussion at https://www.mail-archive.com/ghc-devs@haskell.org/msg05564.html
(This also makes a corresponding update to the `haddock` submodule.)
Test Plan: `sh validate` and new tests pass.
Reviewers: austin, simonpj, goldfire
Reviewed By: austin, simonpj, goldfire
Subscribers: edsko, Fuuzetsu, thomasw, holzensp, goldfire, simonmar, relrod, ezyang, carter
Projects: #ghc
Differential Revision: https://phabricator.haskell.org/D157
|
| | |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This patch set makes us no longer assume that a package key is a human
readable string, leaving Cabal free to "do whatever it wants" to allocate
keys; we'll look up the PackageId in the database to display to the user.
This also means we have a new level of qualifier decisions to make at the
package level, and rewriting some Safe Haskell error reporting code to DTRT.
Additionally, we adjust the build system to use a new ghc-cabal output
Make variable PACKAGE_KEY to determine library names and other things,
rather than concatenating PACKAGE/VERSION as before.
Adds a new `-this-package-key` flag to subsume the old, erroneously named
`-package-name` flag, and `-package-key` to select packages by package key.
RFC: The md5 hashes are pretty tough on the eye, as far as the file
system is concerned :(
ToDo: safePkg01 test had its output updated, but the fix is not really right:
the rest of the dependencies are truncated due to the fact the we're only
grepping a single line, but ghc-pkg is wrapping its output.
ToDo: In a later commit, update all submodules to stop using -package-name
and use -this-package-key. For now, we don't do it to avoid submodule
explosion.
Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
Test Plan: validate
Reviewers: simonpj, simonmar, hvr, austin
Subscribers: simonmar, relrod, carter
Differential Revision: https://phabricator.haskell.org/D80
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Summary:
Previously, the GHC API was "semi" wired-in: it was installed with a
version number, but that version number was hard-coded into the compiler
and it wasn't really possible to install other copies of the GHC API.
This patch makes the GHC API more similar to existing wired-in packages
such as ghc-prim, and will be helpful when we start extending the amount
of information passed to -package-name.
Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
Test Plan: validate
Reviewers: simonmar, simonpj, hvr, austin
Subscribers: simonmar, relrod, carter
Differential Revision: https://phabricator.haskell.org/D78
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
In some cases, the layout of the LANGUAGE/OPTIONS_GHC lines has been
reorganized, while following the convention, to
- place `{-# LANGUAGE #-}` pragmas at the top of the source file, before
any `{-# OPTIONS_GHC #-}`-lines.
- Moreover, if the list of language extensions fit into a single
`{-# LANGUAGE ... -#}`-line (shorter than 80 characters), keep it on one
line. Otherwise split into `{-# LANGUAGE ... -#}`-lines for each
individual language extension. In both cases, try to keep the
enumeration alphabetically ordered.
(The latter layout is preferable as it's more diff-friendly)
While at it, this also replaces obsolete `{-# OPTIONS ... #-}` pragma
occurences by `{-# OPTIONS_GHC ... #-}` pragmas.
|
| |
|
|
|
|
|
| |
This is a first step towards eliminating `default-extensions` in favour of
per-file declared `{-# LANGUAGE ... #-}` pragmas.
Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
|
| |
|
|
| |
Signed-off-by: Austin Seipp <austin@well-typed.com>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This patch improves the call arity analysis in various ways.
Most importantly, it enriches the analysis result information so that
when looking at a call, we do not have to make a random choice about
what side we want to take the information from. Instead we can combine
the results in a way that does not lose valuable information.
To do so, besides the incoming arities, we store remember "what can be
called with what", i.e. an undirected graph between the (interesting)
free variables of an expression. Of course it makes combining the
results a bit more tricky (especially mutual recursion), but still
doable.
The actually implemation of the graph structure is abstractly put away
in a module of its own (UnVarGraph.hs)
The implementation is geared towards efficiently representing the graphs
that we need (which can contain large complete and large complete
bipartite graphs, which would be huge in other representations). If
someone feels like designing data structures: There is surely some
speed-up to be obtained by improving that data structure.
Additionally, the analysis now takes into account that if a RHS stays a
thunk, then its calls happen only once, even if the variables the RHS is
bound to is evaluated multiple times, or is part of a recursive group.
|
| |
|
|
|
|
|
|
|
|
|
|
|
| |
This analysis finds out if a let-bound expression with lower manifest
arity than type arity is always called with more arguments, as in that
case eta-expansion is allowed and often viable. The analysis is very
much tailored towards the code generated when foldl is implemented via
foldr; without this analysis doing so would be a very bad idea!
There are other ways to improve foldr/builder-fusion to cope with foldl,
if any of these are implemented then this step can probably be moved to
-O2 to save some compilation times. The current impact of adding this
phase is just below +2% (measured running GHC's "make").
|
| |
|
|
|
|
|
|
|
|
|
|
|
| |
* CmmRewriteAddignments module was replaced by CmmSink a long
time ago. That module is now available at
https://ghc.haskell.org/trac/ghc/wiki/Commentary/Compiler/Hoopl/Examples
wiki page.
* removeDeadAssignments function was not used and it was also
moved to the above page.
* I also nuked some commented out debugging code that was not
used for 1,5 year.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This patch implements Pattern Synonyms (enabled by -XPatternSynonyms),
allowing y ou to assign names to a pattern and abstract over it.
The rundown is this:
* Named patterns are introduced by the new 'pattern' keyword, and can
be either *unidirectional* or *bidirectional*. A unidirectional
pattern is, in the simplest sense, simply an 'alias' for a pattern,
where the LHS may mention variables to occur in the RHS. A
bidirectional pattern synonym occurs when a pattern may also be used
in expression context.
* Unidirectional patterns are declared like thus:
pattern P x <- x:_
The synonym 'P' may only occur in a pattern context:
foo :: [Int] -> Maybe Int
foo (P x) = Just x
foo _ = Nothing
* Bidirectional patterns are declared like thus:
pattern P x y = [x, y]
Here, P may not only occur as a pattern, but also as an expression
when given values for 'x' and 'y', i.e.
bar :: Int -> [Int]
bar x = P x 10
* Patterns can't yet have their own type signatures; signatures are inferred.
* Pattern synonyms may not be recursive, c.f. type synonyms.
* Pattern synonyms are also exported/imported using the 'pattern'
keyword in an import/export decl, i.e.
module Foo (pattern Bar) where ...
Note that pattern synonyms share the namespace of constructors, so
this disambiguation is required as a there may also be a 'Bar'
type in scope as well as the 'Bar' pattern.
* The semantics of a pattern synonym differ slightly from a typical
pattern: when using a synonym, the pattern itself is matched,
followed by all the arguments. This means that the strictness
differs slightly:
pattern P x y <- [x, y]
f (P True True) = True
f _ = False
g [True, True] = True
g _ = False
In the example, while `g (False:undefined)` evaluates to False,
`f (False:undefined)` results in undefined as both `x` and `y`
arguments are matched to `True`.
For more information, see the wiki:
https://ghc.haskell.org/trac/ghc/wiki/PatternSynonyms
https://ghc.haskell.org/trac/ghc/wiki/PatternSynonyms/Implementation
Reviewed-by: Simon Peyton Jones <simonpj@microsoft.com>
Signed-off-by: Austin Seipp <austin@well-typed.com>
|
| |
|
|
|
|
| |
Instead of panic-ing we now give a sensible message.
There is quite a bit of refactoring here too, removing
several #ifdef GHCI things
|
