Simon Hengel pushed to branch wip/sol/remove-ddump-json-flag at Glasgow Haskell Compiler / GHC Commits: f9d04a6d by Simon Hengel at 2026-06-26T13:48:59+07:00 Remove deprecated flag `-ddump-json` (see #24113) This was first deprecated in 9.10.1. - - - - - 13 changed files: - + changelog.d/remove-ddump-json-flag - compiler/GHC/Driver/Flags.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Types/Error.hs - compiler/GHC/Utils/Logger.hs - docs/users_guide/debugging.rst - ghc/GHCi/UI.hs - testsuite/tests/driver/T16167.stderr - − testsuite/tests/driver/T16167.stdout - testsuite/tests/driver/all.T - testsuite/tests/driver/json2.stderr - − testsuite/tests/driver/json_dump.hs - − testsuite/tests/driver/json_dump.stderr Changes: ===================================== changelog.d/remove-ddump-json-flag ===================================== @@ -0,0 +1,4 @@ +section: compiler +synopsis: Remove deprecated flag `-ddump-json` +issues: #24113 +mrs: !16258 ===================================== compiler/GHC/Driver/Flags.hs ===================================== @@ -527,7 +527,6 @@ data DumpFlag | Opt_D_dump_view_pattern_commoning | Opt_D_verbose_core2core | Opt_D_dump_debug - | Opt_D_dump_json | Opt_D_ppr_debug | Opt_D_no_debug_output | Opt_D_dump_faststrings ===================================== compiler/GHC/Driver/Session.hs ===================================== @@ -1694,9 +1694,6 @@ dynamic_flags_deps = [ (NoArg (setGeneralFlag Opt_NoBignumRules)) , make_ord_flag defGhcFlag "ddump-debug" (setDumpFlag Opt_D_dump_debug) - , make_dep_flag defGhcFlag "ddump-json" - (setDumpFlag Opt_D_dump_json) - "Use `-fdiagnostics-as-json` instead" , make_ord_flag defGhcFlag "dppr-debug" (setDumpFlag Opt_D_ppr_debug) , make_ord_flag defGhcFlag "ddebug-output" ===================================== compiler/GHC/Types/Error.hs ===================================== @@ -549,15 +549,6 @@ instance ToJson Severity where json SevWarning = JSString "Warning" json SevError = JSString "Error" -instance ToJson MessageClass where - json MCOutput = JSString "MCOutput" - json MCFatal = JSString "MCFatal" - json MCInteractive = JSString "MCInteractive" - json MCDump = JSString "MCDump" - json MCInfo = JSString "MCInfo" - json (MCDiagnostic sev reason code) = - JSString $ renderWithContext defaultSDocContext (ppr $ text "MCDiagnostic" <+> ppr sev <+> ppr reason <+> ppr code) - instance ToJson DiagnosticCode where json c = JSInt (fromIntegral (diagnosticCodeNumber c)) ===================================== compiler/GHC/Utils/Logger.hs ===================================== @@ -95,7 +95,6 @@ import GHC.Utils.Panic import GHC.Data.EnumSet (EnumSet) import qualified GHC.Data.EnumSet as EnumSet -import GHC.Data.FastString import System.Directory import System.FilePath ( takeDirectory, () ) @@ -360,7 +359,6 @@ makeThreadSafe logger = do $ pushTraceHook trc $ logger --- See Note [JSON Error Messages] defaultLogJsonAction :: LogJsonAction defaultLogJsonAction logflags msg_class jsdoc = case msg_class of @@ -377,33 +375,6 @@ defaultLogJsonAction logflags msg_class jsdoc = putStrSDoc = defaultLogActionHPutStrDoc logflags False stdout msg = renderJSON jsdoc --- 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 $$ text "")) - where - str = renderWithContext (log_default_user_context logflags) msg - doc = renderJSON $ - JSObject [ ( "span", spanToDumpJSON srcSpan ) - , ( "doc" , JSString str ) - , ( "messageClass", json msg_class ) - ] - spanToDumpJSON :: SrcSpan -> JsonDoc - spanToDumpJSON s = case s of - (RealSrcSpan rss _) -> JSObject [ ("file", json file) - , ("startLine", json $ srcSpanStartLine rss) - , ("startCol", json $ srcSpanStartCol rss) - , ("endLine", json $ srcSpanEndLine rss) - , ("endCol", json $ srcSpanEndCol rss) - ] - where file = unpackFS $ srcSpanFile rss - GeneratedSrcSpan{} -> JSNull - UnhelpfulSpan{} -> JSNull - -- | The default 'LogAction' prints to 'stdout' and 'stderr'. -- -- To replicate the default log action behaviour with different @out@ and @err@ @@ -415,8 +386,7 @@ defaultLogAction = defaultLogActionWithHandles stdout stderr -- Allows clients to replicate the log message formatting of GHC with custom handles. defaultLogActionWithHandles :: Handle {-^ Handle for standard output -} -> Handle {-^ Handle for standard errors -} -> LogAction defaultLogActionWithHandles out err logflags msg_class srcSpan msg - | log_dopt Opt_D_dump_json logflags = jsonLogActionWithHandle out logflags msg_class srcSpan msg - | otherwise = case msg_class of + = case msg_class of MCOutput -> printOut msg MCDump -> printOut (msg $$ blankLine) MCInteractive -> putStrSDoc msg @@ -442,10 +412,6 @@ defaultLogActionWithHandles out err logflags msg_class srcSpan msg -- 2. GHC uses two different code paths for JSON and non-JSON diagnostics. For -- that reason we can not decorate the message in `defaultLogActionWithHandles`. -- --- See also Note [JSON Error Messages]: --- --- `jsonLogAction` should be removed along with -ddump-json --- -- Also note that (1) is the reason why some parts of the compiler produce -- diagnostics that don't respect `-fdiagnostics-as-json`. -- @@ -493,28 +459,6 @@ defaultLogActionHPutStrDoc logflags asciiSpace h d -- calls to this log-action can output all on the same line = printSDoc (log_default_user_context logflags) (Pretty.PageMode asciiSpace) h d --- --- 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. - -- | Default action for 'dumpAction' hook defaultDumpAction :: DumpCache -> LogAction -> DumpAction defaultDumpAction dumps log_action logflags sty flag title _fmt doc = ===================================== docs/users_guide/debugging.rst ===================================== @@ -55,13 +55,6 @@ Dumping out compiler intermediate structures ``Main.p.dump-simpl`` and ``Main.dump-simpl`` instead of overwriting the output of one way with the output of another. -.. 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`. - .. ghc-flag:: -dshow-passes :shortdesc: Print out each pass name as it happens :type: dynamic ===================================== ghc/GHCi/UI.hs ===================================== @@ -508,8 +508,6 @@ interactiveUI config baseDFlags srcs maybe_exprs = do installInteractiveHomeUnits baseDFlags - -- Update the LogAction. Ensure we don't override the user's log action lest - -- we break -ddump-json (#14078) lastErrLocationsRef <- liftIO $ newIORef [] pushLogHookM (ghciLogAction lastErrLocationsRef) ===================================== testsuite/tests/driver/T16167.stderr ===================================== @@ -1 +1 @@ -*** Exception: ExitFailure 1 +{"version":"1.2","ghcVersion":"ghc-9.15.20250819","span":{"file":"T16167.hs","start":{"line":1,"column":8},"end":{"line":1,"column":9}},"severity":"Error","code":58481,"rendered":"T16167.hs:1:8: error: [GHC-58481] parse error on input \u2018f\u2019\n","message":["parse error on input \u2018f\u2019"],"hints":[]} ===================================== testsuite/tests/driver/T16167.stdout deleted ===================================== @@ -1,2 +0,0 @@ -{"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"} ===================================== testsuite/tests/driver/all.T ===================================== @@ -271,12 +271,10 @@ test('T12752pass', normal, compile, ['-DSHOULD_PASS=1 -Wcpp-undef']) test('T12955', normal, makefile_test, []) test('T12971', [when(opsys('mingw32'), fragile(17945)), ignore_stdout], makefile_test, []) -test('json_dump', normal, compile_fail, ['-ddump-json']) test('json', normalise_version('ghc'), compile_fail, ['-fdiagnostics-as-json']) test('json_warn', normalise_version('ghc'), compile, ['-fdiagnostics-as-json -Wunused-matches -Wx-partial']) -test('json2', normalise_version('ghc-internal', 'base','ghc-prim'), compile, ['-ddump-types -ddump-json -Wno-unsupported-llvm-version']) -test('T16167', [normalise_version('ghc'),req_interp,exit_code(1)], run_command, - ['{compiler} -x hs -e ":set prog T16167.hs" -ddump-json T16167.hs']) +test('json2', normalise_version('ghc-internal', 'base','ghc-prim'), compile, ['-ddump-types -fdiagnostics-as-json -Wno-unsupported-llvm-version']) +test('T16167', normalise_version('ghc'), compile_fail, ['-fdiagnostics-as-json']) test('T13604', [], makefile_test, []) test('T13604a', [ js_broken(22261) # require HPC support ===================================== testsuite/tests/driver/json2.stderr ===================================== @@ -1,2 +1,4 @@ -{"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"} +TYPE SIGNATURES + foo :: forall a. a -> a +Dependent modules: [] +Dependent packages: [(normal, base-4.21.0.0)] ===================================== testsuite/tests/driver/json_dump.hs deleted ===================================== @@ -1,6 +0,0 @@ -module Foo where - -import Data.List - -id1 :: a -> a -id1 = 5 ===================================== testsuite/tests/driver/json_dump.stderr deleted ===================================== @@ -1,2 +0,0 @@ -{"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"} View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/f9d04a6dcd1c7ec0214c1f00ce77edf6... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/f9d04a6dcd1c7ec0214c1f00ce77edf6... 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