-   mk_msg msg = mkLocMessage (mkMCDiagnostic diag_opts WarningWithoutFlag Nothing) msg_span

-    messageClass = MCDiagnostic severity (errMsgReason message) (diagnosticCode diagnostic)

-   | Opt_D_dump_json

-                                    (vcat $ pprMsgEnvelopeBagWithLoc (defaultDiagnosticOpts @e) (getMessages whyUnsafe)) $+$

-                             (vcat $ pprMsgEnvelopeBagWithLoc (defaultDiagnosticOpts @GhcMessage) (getMessages msgs))

-  , make_dep_flag defGhcFlag "ddump-json"

-        (setDumpFlag Opt_D_dump_json)

-        "Use `-fdiagnostics-as-json` instead"

-           Nothing  -> pprPanic "initTcDsForSolver" (vcat $ pprMsgEnvelopeBagWithLocDefault (getErrorMessages msgs)) }

-                     in  mkLocMessage (Err.mkMCDiagnostic diag_opts WarningWithoutFlag Nothing)

-import GHC.Utils.Error  (diagReasonSeverity,  pprLocMsgEnvelope )

-       ; let err_msg = pprLocMsgEnvelope (initTcMessageOpts dflags) msg

-  = do { traceTc "Adding diagnostic:" (pprLocMsgEnvelopeDefault msg) ;

-   , MessageClass (..)

-  | MCDiagnostic Severity ResolvedDiagnosticReason (Maybe DiagnosticCode)

-    -- users are encouraged to use the 'mkMCDiagnostic' smart constructor

-import GHC.Utils.Error (pprMsgEnvelopeBagWithLocDefault)

-    . pprMsgEnvelopeBagWithLocDefault

-        pprMessageBag, pprMsgEnvelopeBagWithLoc, pprMsgEnvelopeBagWithLocDefault,

-        pprMessages,

-        pprLocMsgEnvelope, pprLocMsgEnvelopeDefault,

-        mkMCDiagnostic, diagReasonSeverity,

-mkMCDiagnostic :: DiagOpts -> DiagnosticReason -> Maybe DiagnosticCode -> MessageClass

-mkMCDiagnostic opts reason code = MCDiagnostic sev reason' code

-pprMessages :: Diagnostic e => DiagnosticOpts e -> Messages e -> SDoc

-pprMessages e = vcat . pprMsgEnvelopeBagWithLoc e . getMessages

-

-pprMsgEnvelopeBagWithLoc :: Diagnostic e => DiagnosticOpts e -> Bag (MsgEnvelope e) -> [SDoc]

-pprMsgEnvelopeBagWithLoc e bag = [ pprLocMsgEnvelope e item | item <- sortMsgBag Nothing bag ]

-pprMsgEnvelopeBagWithLocDefault :: forall e . Diagnostic e => Bag (MsgEnvelope e) -> [SDoc]

-pprMsgEnvelopeBagWithLocDefault bag = [ pprLocMsgEnvelopeDefault item | item <- sortMsgBag Nothing bag ]

-pprLocMsgEnvelopeDefault :: forall e . Diagnostic e => MsgEnvelope e -> SDoc

-pprLocMsgEnvelopeDefault = pprLocMsgEnvelope (defaultDiagnosticOpts @e)

-pprLocMsgEnvelope :: Diagnostic e => DiagnosticOpts e -> MsgEnvelope e -> SDoc

-pprLocMsgEnvelope opts (MsgEnvelope { errMsgSpan      = s

-        (MCDiagnostic sev reason (diagnosticCode e))

-import GHC.Data.FastString

--- See Note [JSON Error Messages]

--- See Note [JSON Error Messages]

--- this is to be removed

-jsonLogActionWithHandle :: Handle {-^ Standard out -} -> LogAction

-jsonLogActionWithHandle _ _ (MCDiagnostic SevIgnore _ _) _ _ = return () -- suppress the message

-jsonLogActionWithHandle out logflags msg_class srcSpan msg

-  =

-    defaultLogActionHPutStrDoc logflags True out

-      (withPprStyle PprCode (doc $$ text ""))

-    where

-      str = renderWithContext (log_default_user_context logflags) msg

-      doc = renderJSON $

-              JSObject [ ( "span", spanToDumpJSON srcSpan )

-                       , ( "doc" , JSString str )

-                       , ( "messageClass", json msg_class )

-                       ]

-      spanToDumpJSON :: SrcSpan -> JsonDoc

-      spanToDumpJSON s = case s of

-                 (RealSrcSpan rss _) -> JSObject [ ("file", json file)

-                                                , ("startLine", json $ srcSpanStartLine rss)

-                                                , ("startCol", json $ srcSpanStartCol rss)

-                                                , ("endLine", json $ srcSpanEndLine rss)

-                                                , ("endCol", json $ srcSpanEndCol rss)

-                                                ]

-                   where file = unpackFS $ srcSpanFile rss

-                 UnhelpfulSpan _ -> JSNull

-

-  | log_dopt Opt_D_dump_json logflags = jsonLogActionWithHandle out logflags msg_class srcSpan msg

-  | otherwise = case msg_class of

---

--- Note [JSON Error Messages]

--- ~~~~~~~~~~~~~~~~~~~~~~~~~~

---

--- When the user requests the compiler output to be dumped as json

--- we used to collect them all in an IORef and then print them at the end.

--- This doesn't work very well with GHCi. (See #14078) So instead we now

--- use the simpler method of just outputting a JSON document inplace to

--- stdout.

---

--- Before the compiler calls log_action, it has already turned the `ErrMsg`

--- into a formatted message. This means that we lose some possible

--- information to provide to the user but refactoring log_action is quite

--- invasive as it is called in many places. So, for now I left it alone

--- and we can refine its behaviour as users request different output.

---

--- The recent work here replaces the purpose of flag -ddump-json with

--- -fdiagnostics-as-json. For temporary backwards compatibility while

--- -ddump-json is being deprecated, `jsonLogAction` has been added in, but

--- it should be removed along with -ddump-json. Similarly, the guard in

--- `defaultLogAction` should be removed. This cleanup is tracked in #24113.

-

-.. ghc-flag:: -ddump-json

-    :shortdesc: *(deprecated)* Use :ghc-flag:`-fdiagnostics-as-json` instead

-    :type: dynamic

-

-    This flag was previously used to generated JSON formatted GHC diagnostics,

-    but has been deprecated. Instead, use :ghc-flag:`-fdiagnostics-as-json`.

-

-   -- Update the LogAction. Ensure we don't override the user's log action lest

-   -- we break -ddump-json (#14078)

-{"span":null,"doc":"-ddump-json is deprecated: Use `-fdiagnostics-as-json` instead","messageClass":"MCDiagnostic SevWarning WarningWithFlags Opt_WarnDeprecatedFlags :| [] Just GHC-53692"}

-{"span":{"file":"T16167.hs","startLine":1,"startCol":8,"endLine":1,"endCol":9},"doc":"parse error on input \u2018f\u2019","messageClass":"MCDiagnostic SevError ErrorWithoutFlag Just GHC-58481"}

-test('json_dump', normal, compile_fail, ['-ddump-json'])

-test('json2', normalise_version('ghc-internal', 'base','ghc-prim'), compile, ['-ddump-types -ddump-json -Wno-unsupported-llvm-version'])

-     ['{compiler} -x hs -e ":set prog T16167.hs" -ddump-json T16167.hs'])

-{"span":null,"doc":"-ddump-json is deprecated: Use `-fdiagnostics-as-json` instead","messageClass":"MCDiagnostic SevWarning WarningWithFlags Opt_WarnDeprecatedFlags :| [] Just GHC-53692"}

-{"span":null,"doc":"TYPE SIGNATURES\n  foo :: forall a. a -> a\nDependent modules: []\nDependent packages: [(normal, base-4.21.0.0)]","messageClass":"MCOutput"}

-module Foo where

-

-import Data.List

-

-id1 :: a -> a

-id1 = 5

-{"span":null,"doc":"-ddump-json is deprecated: Use `-fdiagnostics-as-json` instead","messageClass":"MCDiagnostic SevWarning WarningWithFlags Opt_WarnDeprecatedFlags :| [] Just GHC-53692"}

-{"span":{"file":"json_dump.hs","startLine":6,"startCol":7,"endLine":6,"endCol":8},"doc":"\u2022 No instance for \u2018Num (a -> a)\u2019 arising from the literal \u20185\u2019\n    (maybe you haven't applied a function to enough arguments?)\n\u2022 In the expression: 5\n  In an equation for \u2018id1\u2019: id1 = 5","messageClass":"MCDiagnostic SevError ErrorWithoutFlag Just GHC-39999"}