Template Haskell Uniq ~ Int leads to external interpreter cross compilation trouble

64 bit GHC has 64 bit Unique values, but they don't fit in a template-haskell NameU when cross-compiling to a 32 bit target.

In theory we can support Template Haskell in this situation with -fexternal-interpreter (and the earlier GHCJS implementation), but when the target cannot represent GHC's uniques in an Int, things go wrong:

from Language.Haskell.TH.Syntax:

type Uniq = Int

I think we can fix this for now by changing the synonym to type Uniq = Int64 (or even type Uniq = Integer), making the template-haskell Uniq at least as big as the GHC Unique in practice. This requires a change in DsMeta.

the uses of Int below should really be changed to Uniq

data NameFlavour
  = NameS           -- ^ An unqualified name; dynamically bound
  | NameQ ModName   -- ^ A qualified name; dynamically bound
  | NameU !Int      -- ^ A unique local name
  | NameL !Int      -- ^ Local name bound outside of the TH AST
  | NameG NameSpace PkgName ModName -- ^ Global name bound outside of the TH AST:
                -- An original name (occurrences only, not binders)
                -- Need the namespace too to be sure which
                -- thing we are naming
  deriving ( Data, Eq, Ord, Show, Generic )

-- Global variable to generate unique symbols
counter :: IORef Int
{-# NOINLINE counter #-}
counter = unsafePerformIO (newIORef 0)

Trac metadata

Trac field	Value
Version	8.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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