A fake ghc script to inspect what options cabal passes

fakeghc

#!/usr/bin/env bash

# Use getopt to parse long options
OPTIONS=$(getopt -o '' --long numeric-version -o '' --long supported-languages -o '' --long info -o '' --long print-global-package-db -o '' --long print-libdir -- "$@" 2>/dev/null)
if [ $? -ne 0 ]; then
  echo HERE: fakeghc $@
  exit 0
fi

# Reorder the positional parameters according to getopt's output
eval set -- "$OPTIONS"

# Flag to track if --numeric-version was passed
NUMERIC_VERSION=false
SUPPORTED_LANGUAGES=false
INFO=false

# Process options
while true; do
  case "$1" in
    --numeric-version)
      NUMERIC_VERSION=true
      shift
      ;;
    --supported-languages)
      SUPPORTED_LANGUAGES=true
      shift
      ;;
    --info)
      INFO=true
      shift
      ;;
    --print-global-package-db)
      PRINT_GLOBAL_PACKAGE_DB=true
      shift
      ;;
    --print-libdir)
      PRINT_LIBDIR=true
      shift
      ;;
    --)
      shift
      break
      ;;
    *)
      echo "Unexpected option: $1" >&2
      exit 1
      ;;
  esac
done

languages=$(cat << EOF
Haskell98
Haskell2010
GHC2021
Unsafe
Trustworthy
Safe
AllowAmbiguousTypes
NoAllowAmbiguousTypes
AlternativeLayoutRule
NoAlternativeLayoutRule
AlternativeLayoutRuleTransitional
NoAlternativeLayoutRuleTransitional
Arrows
NoArrows
AutoDeriveTypeable
NoAutoDeriveTypeable
BangPatterns
NoBangPatterns
BinaryLiterals
NoBinaryLiterals
CApiFFI
NoCApiFFI
CPP
NoCPP
CUSKs
NoCUSKs
ConstrainedClassMethods
NoConstrainedClassMethods
ConstraintKinds
NoConstraintKinds
DataKinds
NoDataKinds
DatatypeContexts
NoDatatypeContexts
DefaultSignatures
NoDefaultSignatures
DeriveAnyClass
NoDeriveAnyClass
DeriveDataTypeable
NoDeriveDataTypeable
DeriveFoldable
NoDeriveFoldable
DeriveFunctor
NoDeriveFunctor
DeriveGeneric
NoDeriveGeneric
DeriveLift
NoDeriveLift
DeriveTraversable
NoDeriveTraversable
DerivingStrategies
NoDerivingStrategies
DerivingVia
NoDerivingVia
DisambiguateRecordFields
NoDisambiguateRecordFields
DoAndIfThenElse
NoDoAndIfThenElse
BlockArguments
NoBlockArguments
DoRec
NoDoRec
DuplicateRecordFields
NoDuplicateRecordFields
FieldSelectors
NoFieldSelectors
EmptyCase
NoEmptyCase
EmptyDataDecls
NoEmptyDataDecls
EmptyDataDeriving
NoEmptyDataDeriving
ExistentialQuantification
NoExistentialQuantification
ExplicitForAll
NoExplicitForAll
ExplicitNamespaces
NoExplicitNamespaces
ExtendedDefaultRules
NoExtendedDefaultRules
ExtendedLiterals
NoExtendedLiterals
FlexibleContexts
NoFlexibleContexts
FlexibleInstances
NoFlexibleInstances
ForeignFunctionInterface
NoForeignFunctionInterface
FunctionalDependencies
NoFunctionalDependencies
GADTSyntax
NoGADTSyntax
GADTs
NoGADTs
GHCForeignImportPrim
NoGHCForeignImportPrim
GeneralizedNewtypeDeriving
NoGeneralizedNewtypeDeriving
GeneralisedNewtypeDeriving
NoGeneralisedNewtypeDeriving
ImplicitParams
NoImplicitParams
ImplicitPrelude
NoImplicitPrelude
ImportQualifiedPost
NoImportQualifiedPost
ImpredicativeTypes
NoImpredicativeTypes
IncoherentInstances
NoIncoherentInstances
TypeFamilyDependencies
NoTypeFamilyDependencies
InstanceSigs
NoInstanceSigs
ApplicativeDo
NoApplicativeDo
InterruptibleFFI
NoInterruptibleFFI
NoJavaScriptFFI
KindSignatures
NoKindSignatures
LambdaCase
NoLambdaCase
LexicalNegation
NoLexicalNegation
LiberalTypeSynonyms
NoLiberalTypeSynonyms
LinearTypes
NoLinearTypes
MagicHash
NoMagicHash
MonadComprehensions
NoMonadComprehensions
MonoLocalBinds
NoMonoLocalBinds
DeepSubsumption
NoDeepSubsumption
MonomorphismRestriction
NoMonomorphismRestriction
MultiParamTypeClasses
NoMultiParamTypeClasses
MultiWayIf
NoMultiWayIf
NumericUnderscores
NoNumericUnderscores
NPlusKPatterns
NoNPlusKPatterns
NamedFieldPuns
NoNamedFieldPuns
NamedWildCards
NoNamedWildCards
NegativeLiterals
NoNegativeLiterals
HexFloatLiterals
NoHexFloatLiterals
NondecreasingIndentation
NoNondecreasingIndentation
NullaryTypeClasses
NoNullaryTypeClasses
NumDecimals
NoNumDecimals
OverlappingInstances
NoOverlappingInstances
OverloadedLabels
NoOverloadedLabels
OverloadedLists
NoOverloadedLists
OverloadedStrings
NoOverloadedStrings
PackageImports
NoPackageImports
ParallelArrays
NoParallelArrays
ParallelListComp
NoParallelListComp
PartialTypeSignatures
NoPartialTypeSignatures
PatternGuards
NoPatternGuards
PatternSignatures
NoPatternSignatures
PatternSynonyms
NoPatternSynonyms
PolyKinds
NoPolyKinds
PolymorphicComponents
NoPolymorphicComponents
QuantifiedConstraints
NoQuantifiedConstraints
PostfixOperators
NoPostfixOperators
QuasiQuotes
NoQuasiQuotes
QualifiedDo
NoQualifiedDo
Rank2Types
NoRank2Types
RankNTypes
NoRankNTypes
RebindableSyntax
NoRebindableSyntax
OverloadedRecordDot
NoOverloadedRecordDot
OverloadedRecordUpdate
NoOverloadedRecordUpdate
RecordPuns
NoRecordPuns
RecordWildCards
NoRecordWildCards
RecursiveDo
NoRecursiveDo
RelaxedLayout
NoRelaxedLayout
RelaxedPolyRec
NoRelaxedPolyRec
RoleAnnotations
NoRoleAnnotations
ScopedTypeVariables
NoScopedTypeVariables
StandaloneDeriving
NoStandaloneDeriving
StarIsType
NoStarIsType
StaticPointers
NoStaticPointers
Strict
NoStrict
StrictData
NoStrictData
TemplateHaskell
NoTemplateHaskell
TemplateHaskellQuotes
NoTemplateHaskellQuotes
StandaloneKindSignatures
NoStandaloneKindSignatures
TraditionalRecordSyntax
NoTraditionalRecordSyntax
TransformListComp
NoTransformListComp
TupleSections
NoTupleSections
TypeAbstractions
NoTypeAbstractions
TypeApplications
NoTypeApplications
TypeData
NoTypeData
TypeInType
NoTypeInType
TypeFamilies
NoTypeFamilies
TypeOperators
NoTypeOperators
TypeSynonymInstances
NoTypeSynonymInstances
UnboxedTuples
NoUnboxedTuples
UnboxedSums
NoUnboxedSums
UndecidableInstances
NoUndecidableInstances
UndecidableSuperClasses
NoUndecidableSuperClasses
UnicodeSyntax
NoUnicodeSyntax
UnliftedDatatypes
NoUnliftedDatatypes
UnliftedFFITypes
NoUnliftedFFITypes
UnliftedNewtypes
NoUnliftedNewtypes
ViewPatterns
NoViewPatterns
EOF
)

info=$(cat << EOF
 [("Project name","The Glorious Glasgow Haskell Compilation System")
 ,("C compiler command","/nix/store/95k9rsn1zsw1yvir8mj824ldhf90i4qw-gcc-wrapper-14.3.0/bin/cc")
 ,("C compiler flags","")
 ,("C compiler link flags","-fuse-ld=gold ")
 ,("C compiler supports -no-pie","YES")
 ,("C++ compiler command","/nix/store/95k9rsn1zsw1yvir8mj824ldhf90i4qw-gcc-wrapper-14.3.0/bin/c++")
 ,("C++ compiler flags","")
 ,("Haskell CPP command","/nix/store/95k9rsn1zsw1yvir8mj824ldhf90i4qw-gcc-wrapper-14.3.0/bin/cc")
 ,("Haskell CPP flags","-E -undef -traditional")
 ,("LLVM clang command","clang")
 ,("LLVM llc command","llc")
 ,("LLVM opt command","opt")
 ,("LLVM target","x86_64-unknown-linux")
 ,("Leading underscore","NO")
 ,("Merge objects command","/nix/store/l19cddv64i52rhcwahif8sgyrd3mhiqb-binutils-wrapper-2.44/bin/ld.gold")
 ,("Merge objects flags","-r")
 ,("RTS expects libdw","YES")
 ,("RTS ways","debug thr thr_debug thr_p dyn debug_dyn thr_dyn thr_debug_dyn thr_debug_p debug_p")
 ,("Support SMP","YES")
 ,("Tables next to code","YES")
 ,("Unregisterised","NO")
 ,("Use LibFFI","NO")
 ,("Use inplace MinGW toolchain","NO")
 ,("Use interpreter","YES")
 ,("ar command","/nix/store/l19cddv64i52rhcwahif8sgyrd3mhiqb-binutils-wrapper-2.44/bin/ar")
 ,("ar flags","q")
 ,("ar supports -L","NO")
 ,("ar supports at file","YES")
 ,("cross compiling","NO")
 ,("dllwrap command","/bin/false")
 ,("install_name_tool command","install_name_tool")
 ,("ld command","/nix/store/l19cddv64i52rhcwahif8sgyrd3mhiqb-binutils-wrapper-2.44/bin/ld.gold")
 ,("ld flags","")
 ,("ld is GNU ld","YES")
 ,("ld supports compact unwind","YES")
 ,("ld supports filelist","NO")
 ,("ld supports response files","YES")
 ,("ld supports single module","NO")
 ,("otool command","otool")
 ,("ranlib command","/nix/store/l19cddv64i52rhcwahif8sgyrd3mhiqb-binutils-wrapper-2.44/bin/ranlib")
 ,("target arch","ArchX86_64")
 ,("target has .ident directive","YES")
 ,("target has GNU nonexec stack","YES")
 ,("target has libm","YES")
 ,("target has subsections via symbols","NO")
 ,("target os","OSLinux")
 ,("target platform string","x86_64-unknown-linux")
 ,("target word big endian","NO")
 ,("target word size","8")
 ,("touch command","touch")
 ,("unlit command","/nix/store/w6awqpzhn1pmfzql7ba5ar8pvs0yq5s2-ghc-9.8.4/lib/ghc-9.8.4/lib/bin/unlit")
 ,("windres command","/bin/false")
 ,("Project version","9.8.4")
 ,("Project Git commit id","a3401159f2846605abb517e71af463df47398e72")
 ,("Project Version Int","908")
 ,("Project Patch Level","4")
 ,("Project Patch Level1","4")
 ,("Project Patch Level2","0")
 ,("Project Unit Id","ghc-9.8.4-a150")
 ,("Booter version","9.6.3")
 ,("Stage","2")
 ,("Build platform","x86_64-unknown-linux")
 ,("Host platform","x86_64-unknown-linux")
 ,("Target platform","x86_64-unknown-linux")
 ,("Have interpreter","YES")
 ,("Object splitting supported","NO")
 ,("Have native code generator","YES")
 ,("target has RTS linker","YES")
 ,("Target default backend","native code generator")
 ,("Support dynamic-too","YES")
 ,("Support parallel --make","YES")
 ,("Support reexported-modules","YES")
 ,("Support thinning and renaming package flags","YES")
 ,("Support Backpack","YES")
 ,("Requires unified installed package IDs","YES")
 ,("Uses package keys","YES")
 ,("Uses unit IDs","YES")
 ,("GHC Dynamic","YES")
 ,("GHC Profiled","NO")
 ,("Debug on","NO")
 ,("LibDir","/nix/store/w6awqpzhn1pmfzql7ba5ar8pvs0yq5s2-ghc-9.8.4/lib/ghc-9.8.4/lib")
 ,("Global Package DB","/nix/store/w6awqpzhn1pmfzql7ba5ar8pvs0yq5s2-ghc-9.8.4/lib/ghc-9.8.4/lib/package.conf.d")
 ]
EOF
)

if [ "$NUMERIC_VERSION" = true ]; then
  echo "9.8.4"
elif [ "$SUPPORTED_LANGUAGES" = true ]; then
  echo "$languages"
elif [ "$INFO" = true ]; then
  echo "$info"
elif [ "$PRINT_GLOBAL_PACKAGE_DB" = true ]; then
  echo "/nix/store/w6awqpzhn1pmfzql7ba5ar8pvs0yq5s2-ghc-9.8.4/lib/ghc-9.8.4/lib/package.conf.d"
elif [ "$PRINT_LIBDIR" = true ]; then
  echo "/nix/store/w6awqpzhn1pmfzql7ba5ar8pvs0yq5s2-ghc-9.8.4/lib/ghc-9.8.4/lib"
else
  echo HERE: fakeghc $@
fi