diff options
Diffstat (limited to 'compiler/GHC/Tc/Errors/Ppr.hs')
| -rw-r--r-- | compiler/GHC/Tc/Errors/Ppr.hs | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/compiler/GHC/Tc/Errors/Ppr.hs b/compiler/GHC/Tc/Errors/Ppr.hs index 59bde4f0aa..b8ed303dd7 100644 --- a/compiler/GHC/Tc/Errors/Ppr.hs +++ b/compiler/GHC/Tc/Errors/Ppr.hs @@ -41,7 +41,7 @@ import GHC.Core.Predicate import GHC.Core.Type import GHC.Driver.Flags - +import GHC.Driver.Backend import GHC.Hs import GHC.Tc.Errors.Types @@ -737,12 +737,9 @@ instance Diagnostic TcRnMessage where text "possible missing & in foreign import of FunPtr" TcRnIllegalForeignDeclBackend _decl _backend expectedBknds - -> mkSimpleDecorated $ text "Illegal foreign declaration:" <+> - case expectedBknds of - COrAsmOrLlvm -> - text "requires unregisterised, llvm (-fllvm) or native code generation (-fasm)" - COrAsmOrLlvmOrInterp -> - text "requires interpreted, unregisterised, llvm or native code generation" + -> mkSimpleDecorated $ + fsep (text "Illegal foreign declaration: requires one of these back ends:" : + commafyWith (text "or") (map (text . backendDescription) expectedBknds)) TcRnUnsupportedCallConv _decl unsupportedCC -> mkSimpleDecorated $ @@ -1481,6 +1478,18 @@ instance Diagnostic TcRnMessage where TcRnUnpromotableThing{} -> noHints + +-- | Change [x] to "x", [x, y] to "x and y", [x, y, z] to "x, y, and z", +-- and so on. The `and` stands for any `conjunction`, which is passed in. +commafyWith :: SDoc -> [SDoc] -> [SDoc] +commafyWith _ [] = [] +commafyWith _ [x] = [x] +commafyWith conjunction [x, y] = [x <+> conjunction <+> y] +commafyWith conjunction xs = addConjunction $ punctuate comma xs + where addConjunction [x, y] = [x, conjunction, y] + addConjunction (x : xs) = x : addConjunction xs + addConjunction _ = panic "commafyWith expected 2 or more elements" + deriveInstanceErrReasonHints :: Class -> UsingGeneralizedNewtypeDeriving -> DeriveInstanceErrReason |