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| author | Apoorv Ingle <apoorv-ingle@uiowa.edu> | 2023-02-06 09:13:10 -0600 |
|---|---|---|
| committer | Apoorv Ingle <apoorv-ingle@uiowa.edu> | 2023-03-06 08:40:40 -0600 |
| commit | f5c3ae02d74d94d3183f288fb70a076babf338b2 (patch) | |
| tree | 0786841b680fbaa4e86c809d47145cb3c215d60b /compiler/GHC/Driver/Session.hs | |
| parent | bf43ba9215a726039ace7bac37c0a223a912d998 (diff) | |
| download | haskell-wip/T21909.tar.gz | |
Constraint simplification loop now depends on `ExpansionFuel`wip/T21909
instead of a boolean flag for `CDictCan.cc_pend_sc`.
Pending givens get a fuel of 3 while Wanted and quantified constraints get a fuel of 1.
This helps pending given constraints to keep up with pending wanted constraints in case of
`UndecidableSuperClasses` and superclass expansions while simplifying the infered type.
Adds 3 dynamic flags for controlling the fuels for each type of constraints
`-fgivens-expansion-fuel` for givens `-fwanteds-expansion-fuel` for wanteds and `-fqcs-expansion-fuel` for quantified constraints
Fixes #21909
Added Tests T21909, T21909b
Added Note [Expanding Recursive Superclasses and ExpansionFuel]
Diffstat (limited to 'compiler/GHC/Driver/Session.hs')
| -rw-r--r-- | compiler/GHC/Driver/Session.hs | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/compiler/GHC/Driver/Session.hs b/compiler/GHC/Driver/Session.hs index 2ad09bc7c6..20fcc3f6fe 100644 --- a/compiler/GHC/Driver/Session.hs +++ b/compiler/GHC/Driver/Session.hs @@ -517,7 +517,15 @@ data DynFlags = DynFlags { reductionDepth :: IntWithInf, -- ^ Typechecker maximum stack depth solverIterations :: IntWithInf, -- ^ Number of iterations in the constraints solver -- Typically only 1 is needed - + givensFuel :: Int, -- ^ Number of layers of superclass expansion for givens + -- Should be < solverIterations + -- See Note [Expanding Recursive Superclasses and ExpansionFuel] + wantedsFuel :: Int, -- ^ Number of layers of superclass expansion for wanteds + -- Should be < givensFuel + -- See Note [Expanding Recursive Superclasses and ExpansionFuel] + qcsFuel :: Int, -- ^ Number of layers of superclass expansion for quantified constraints + -- Should be < givensFuel + -- See Note [Expanding Recursive Superclasses and ExpansionFuel] homeUnitId_ :: UnitId, -- ^ Target home unit-id homeUnitInstanceOf_ :: Maybe UnitId, -- ^ Id of the unit to instantiate homeUnitInstantiations_ :: [(ModuleName, Module)], -- ^ Module instantiations @@ -1148,6 +1156,9 @@ defaultDynFlags mySettings = mainFunIs = Nothing, reductionDepth = treatZeroAsInf mAX_REDUCTION_DEPTH, solverIterations = treatZeroAsInf mAX_SOLVER_ITERATIONS, + givensFuel = mAX_GIVENS_FUEL, + wantedsFuel = mAX_WANTEDS_FUEL, + qcsFuel = mAX_QC_FUEL, homeUnitId_ = mainUnitId, homeUnitInstanceOf_ = Nothing, @@ -2733,6 +2744,12 @@ dynamic_flags_deps = [ (intSuffix (\n d -> d { reductionDepth = treatZeroAsInf n })) , make_ord_flag defFlag "fconstraint-solver-iterations" (intSuffix (\n d -> d { solverIterations = treatZeroAsInf n })) + , make_ord_flag defFlag "fgivens-expansion-fuel" + (intSuffix (\n d -> d { givensFuel = n })) + , make_ord_flag defFlag "fwanteds-expansion-fuel" + (intSuffix (\n d -> d { wantedsFuel = n })) + , make_ord_flag defFlag "fqcs-expansion-fuel" + (intSuffix (\n d -> d { qcsFuel = n })) , (Deprecated, defFlag "fcontext-stack" (intSuffixM (\n d -> do { deprecate $ "use -freduction-depth=" ++ show n ++ " instead" |