| Commit message (Collapse) | Author | Age | Files | Lines |
|---|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Here we introduce a new data structure, RoughMap, inspired by the
previous `RoughTc` matching mechanism for checking instance matches.
This allows [Fam]InstEnv to be implemented as a trie indexed by these
RoughTc signatures, reducing the complexity of instance lookup and
FamInstEnv merging (done during the family instance conflict test)
from O(n) to O(log n).
The critical performance improvement currently realised by this patch is
in instance matching. In particular the RoughMap mechanism allows us to
discount many potential instances which will never match for constraints
involving type variables (see Note [Matching a RoughMap]). In realistic
code bases matchInstEnv was accounting for 50% of typechecker time due
to redundant work checking instances when simplifying instance contexts
when deriving instances. With this patch the cost is significantly
reduced.
The larger constants in InstEnv creation do mean that a few small
tests regress in allocations slightly. However, the runtime of T19703 is
reduced by a factor of 4. Moreover, the compilation time of the Cabal
library is slightly improved.
A couple of test cases are included which demonstrate significant
improvements in compile time with this patch.
This unfortunately does not fix the testcase provided in #19703 but does
fix #20933
-------------------------
Metric Decrease:
T12425
Metric Increase:
T13719
T9872a
T9872d
hard_hole_fits
-------------------------
Co-authored-by: Matthew Pickering <matthewtpickering@gmail.com>
|
| |
|
|
|
|
|
|
|
|
|
|
| |
Plugins were directly fetched from HscEnv (hsc_static_plugins and
hsc_plugins). The tight coupling of plugins and of HscEnv is undesirable
and it's better to store them in a new Plugins datatype and to use it in
the plugins' API (e.g. withPlugins, mapPlugins...).
In the process, the interactive context (used by GHCi) got proper
support for different static plugins than those used for loaded modules.
Bump haddock submodule
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Names defined earier but shadowed need to be kept around, e.g. for type
signatures:
```
ghci> data T = T
ghci> let t = T
ghci> data T = T
ghci> :t t
t :: Ghci1.T
```
and indeed they can be used:
```
ghci> let t2 = Ghci1.T :: Ghci1.T
ghci> :t t2
t2 :: Ghci1.T
```
However, previously this did not happen for ids (non-types), although they
are still around under the qualified name internally:
```
ghci> let t = "other t"
ghci> t'
<interactive>:8:1: error:
• Variable not in scope: t'
• Perhaps you meant one of these:
‘Ghci2.t’ (imported from Ghci2), ‘t’ (line 7), ‘t2’ (line 5)
ghci> Ghci2.t
<interactive>:9:1: error:
• GHC internal error: ‘Ghci2.t’ is not in scope during type checking, but it passed the renamer
tcl_env of environment: []
• In the expression: Ghci2.t
In an equation for ‘it’: it = Ghci2.t
```
This fixes the problem by simply removing the code that tries to remove
shadowed ids from the environment. Now you can refer to shadowed ids using
`Ghci2.t`, just like you can do for data and type constructors. This
simplifies the code, makes terms and types more similar, and also
fixes #20455.
Now all names ever defined in GHCi are in `ic_tythings`, which is printed by
`:show bindings`. But for that commands, it seems to be more ergonomic
to only list those bindings that are not shadowed. Or, even if it is not
more ergonomic, it’s the current behavour. So let's restore that by filtering
in `icInScopeTTs`.
Of course a single `TyThing` can be associated with many names. We keep
it it in the bindings if _any_ of its names are still visible
unqualifiedly. It's a judgement call.
This commit also turns a rather old comment into a test files.
The comment is is rather stale and things are better explained
elsewhere. Fixes #925.
Two test cases are regressing:
T14052(ghci) ghc/alloc 2749444288.0 12192109912.0 +343.4% BAD
T14052Type(ghci) ghc/alloc 7365784616.0 10767078344.0 +46.2% BAD
This is not unexpected; the `ic_tythings list grows` a lot more if we
don’t remove shadowed Ids. I tried to alleviate it a bit with earlier
MRs, but couldn’t make up for it completely.
Metric Increase:
T14052
T14052Type
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
The GlobalRdrEnv of a GHCI session changes in odd ways: New bindings are
not just added "to the end", but also "in the middle", namely when
changing the set of imports: These are treated as if they happened
before all bindings from the prompt, even those that happened earlier.
Previously, this meant that the `ic_rn_gbl_env` is recalculated from the
`ic_tythings`. But this wasteful if `ic_tythings` has many entries that
define the same unqualified name. By separately keeping track of a
`GlobalRdrEnv` of all the locally defined things we can speed this
operation up significantly.
This change improves `T14052Type` by 60% (It used to be 70%, but it
looks that !6723 already reaped some of the rewards).
But more importantly, it hopefully unblocks #20455, becaues with this
smarter caching, the change needed to fix that issue will no longer make
`T14052` explode. I hope.
It does regress `T14052` by 30%; caching isn’t free. Oh well.
Metric Decrease:
T14052Type
Metric Increase:
T14052
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
| |
this allows us to use a smarter implementation based on
`Data.IntSet.differenceWith`, which should do less work. Also, it will
unblock improvements to !6703.
The `OccEnv a` really denotes a set of `OccName`s. We are not using
`OccSet`, though, because that is an `OccEnv OccName`, and we in !6703
we want to use this with differently-valued `OccEnv`s. But `OccSet`s are
readily and safely coerced into `OccEnv`s.
There is no other use of `delLocalRdrEnvList` remaining, so removing
that.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
previously, the `shadowNames` function would take `[GreName]`. This has
confused me for two reasons:
* Why `GreName` and not `Name`? Does the difference between a normal
name and a field name matter? The code of `shadowNames` shows that it
does not, but really its better if the type signatures says so.
* Why `Name` and not `OccName`? The point of `shadowNames` is to shadow
_unqualified names_, at least in the two use cases I am aware of
(names defined on the GHCI prompt or in TH splices).
The code of `shadowNames` used to have cases that peek at the module
of the given name and do something if that module appears in the
`GlobalRdrElt`, but I think these cases are dead code, I don’t see
how they could occur in the above use cases. Also, I replaced them
with `errors` and GHC would still validate. Hence removing this code
(yay!)
This change also allows `shadowNames` to accept an `OccSet` instead,
which allows for a faster implemenation; I’ll try that separately. This
in stead might help with !6703.
|
| |
|
|
|
|
|
| |
Previously, defining fields with DuplicateRecordFields in GHCi lead to
strange shadowing behaviour, whereby fields would (accidentally) not
shadow other fields. This simplifies things so that fields are shadowed
in the same way whether or not DuplicateRecordFields is enabled.
|
| | |
|
| |
|
|
|
|
|
|
|
|
|
|
|
| |
The unit database cache, the home unit and the unit state were stored in
DynFlags while they ought to be stored in the compiler session state
(HscEnv). This patch fixes this.
It introduces a new UnitEnv type that should be used in the future to
handle separate unit environments (especially host vs target units).
Related to #17957
Bump haddock submodule
|
| |
|
|
|
|
|
|
|
|
| |
Loaded plugins have nothing to do in DynFlags so this patch moves them
into HscEnv (session state).
"DynFlags plugins" become "Driver plugins" to still be able to register
static plugins.
Bump haddock submodule
|
|
|
I was working on making DynFlags stateless (#17957), especially by
storing loaded plugins into HscEnv instead of DynFlags. It turned out to
be complicated because HscEnv is in GHC.Driver.Types but LoadedPlugin
isn't: it is in GHC.Driver.Plugins which depends on GHC.Driver.Types. I
didn't feel like introducing yet another hs-boot file to break the loop.
Additionally I remember that while we introduced the module hierarchy
(#13009) we talked about splitting GHC.Driver.Types because it contained
various unrelated types and functions, but we never executed. I didn't
feel like making GHC.Driver.Types bigger with more unrelated Plugins
related types, so finally I bit the bullet and split GHC.Driver.Types.
As a consequence this patch moves a lot of things. I've tried to put
them into appropriate modules but nothing is set in stone.
Several other things moved to avoid loops.
* Removed Binary instances from GHC.Utils.Binary for random compiler
things
* Moved Typeable Binary instances into GHC.Utils.Binary.Typeable: they
import a lot of things that users of GHC.Utils.Binary don't want to
depend on.
* put everything related to Units/Modules under GHC.Unit:
GHC.Unit.Finder, GHC.Unit.Module.{ModGuts,ModIface,Deps,etc.}
* Created several modules under GHC.Types: GHC.Types.Fixity, SourceText,
etc.
* Split GHC.Utils.Error (into GHC.Types.Error)
* Finally removed GHC.Driver.Types
Note that this patch doesn't put loaded plugins into HscEnv. It's left
for another patch.
Bump haddock submodule
|
