Remove -XMonadFailDesugaring references

7 files changed, 7 insertions, 33 deletions

diff --git a/compiler/GHC/Driver/Session.hs b/compiler/GHC/Driver/Session.hs
index 8e92fc974f..64c945a7cf 100644
--- a/compiler/GHC/Driver/Session.hs
+++ b/compiler/GHC/Driver/Session.hs
@@ -3647,8 +3647,6 @@ xFlagsDeps = [
   flagSpec "LinearTypes"                      LangExt.LinearTypes,
   flagSpec "MagicHash"                        LangExt.MagicHash,
   flagSpec "MonadComprehensions"              LangExt.MonadComprehensions,
-  depFlagSpec "MonadFailDesugaring"           LangExt.MonadFailDesugaring
-    "MonadFailDesugaring is now the default behavior",
   flagSpec "MonoLocalBinds"                   LangExt.MonoLocalBinds,
   depFlagSpecCond "MonoPatBinds"              LangExt.MonoPatBinds
     id
diff --git a/compiler/GHC/Rename/Expr.hs b/compiler/GHC/Rename/Expr.hs
index bfa773ed9f..55618978a5 100644
--- a/compiler/GHC/Rename/Expr.hs
+++ b/compiler/GHC/Rename/Expr.hs
@@ -780,10 +780,9 @@ exhaustive list). How we deal with pattern match failure is context-dependent.
    entirely. So, for list comprehensions, the fail function is set to 'Nothing'
    for clarity.
 
- * In the case of monadic contexts (e.g. monad comprehensions, do, and mdo
-   expressions) we want pattern match failure to be desugared to the appropriate
-   'fail' function (either that of Monad or MonadFail, depending on whether
-   -XMonadFailDesugaring is enabled.)
+* In the case of monadic contexts (e.g. monad comprehensions, do, and mdo
+   expressions) we want pattern match failure to be desugared to the
+   'fail' function (from MonadFail type class).
 
 At one point we failed to make this distinction, leading to #11216.
 -}
diff --git a/docs/users_guide/exts/monadfail_desugaring.rst b/docs/users_guide/exts/monadfail_desugaring.rst
deleted file mode 100644
index 1232bf3283..0000000000
--- a/docs/users_guide/exts/monadfail_desugaring.rst
+++ /dev/null
@@ -1,23 +0,0 @@
-.. _monadfail-desugaring:
-
-New monadic failure desugaring mechanism
-----------------------------------------
-
-.. extension:: MonadFailDesugaring
-    :shortdesc: Enable monadfail desugaring.
-
-    :since: 8.0.1
-
-    Use the ``MonadFail.fail`` instead of the legacy ``Monad.fail`` function
-    when desugaring refutable patterns in ``do`` blocks.
-
-The ``-XMonadFailDesugaring`` extension switches the desugaring of
-``do``-blocks to use ``MonadFail.fail`` instead of ``Monad.fail``.
-
-This extension is enabled by default since GHC 8.6.1, under the
-`MonadFail Proposal (MFP)
-<https://gitlab.haskell.org/haskell/prime/-/wikis/libraries/proposals/monad-fail>`__.
-
-This extension is temporary, and will be deprecated in a future release.
-
-
diff --git a/docs/users_guide/exts/syntax.rst b/docs/users_guide/exts/syntax.rst
index bb29b55772..7cbc5cf198 100644
--- a/docs/users_guide/exts/syntax.rst
+++ b/docs/users_guide/exts/syntax.rst
@@ -14,7 +14,6 @@ Syntax
     parallel_list_comprehensions
     generalised_list_comprehensions
     monad_comprehensions
-    monadfail_desugaring
     overloaded_lists
     rebindable_syntax
     tuple_sections
diff --git a/libraries/ghc-boot-th/GHC/LanguageExtensions/Type.hs b/libraries/ghc-boot-th/GHC/LanguageExtensions/Type.hs
index b455fab533..d8478c8e39 100644
--- a/libraries/ghc-boot-th/GHC/LanguageExtensions/Type.hs
+++ b/libraries/ghc-boot-th/GHC/LanguageExtensions/Type.hs
@@ -138,7 +138,6 @@ data Extension
    | TypeApplications
    | Strict
    | StrictData
-   | MonadFailDesugaring
    | EmptyDataDeriving
    | NumericUnderscores
    | QuantifiedConstraints
diff --git a/testsuite/tests/driver/T4437.hs b/testsuite/tests/driver/T4437.hs
index c83d29b03d..78d552c6cd 100644
--- a/testsuite/tests/driver/T4437.hs
+++ b/testsuite/tests/driver/T4437.hs
@@ -53,4 +53,6 @@ expectedCabalOnlyExtensions = ["Generics",
                                "SafeImports",
                                "Safe",
                                "Unsafe",
-                               "Trustworthy"]
+                               "Trustworthy",
+                               "MonadFailDesugaring"
+                              ]
diff --git a/testsuite/tests/simplCore/should_run/T3591.hs b/testsuite/tests/simplCore/should_run/T3591.hs
index fc49c00cdb..09724fef62 100644
--- a/testsuite/tests/simplCore/should_run/T3591.hs
+++ b/testsuite/tests/simplCore/should_run/T3591.hs
@@ -20,7 +20,7 @@
 -- | Module "Trampoline" defines the pipe computations and their basic building blocks.
 
 {-# LANGUAGE ScopedTypeVariables, Rank2Types, MultiParamTypeClasses,
-             TypeFamilies, KindSignatures, FlexibleContexts, NoMonadFailDesugaring,
+             TypeFamilies, KindSignatures, FlexibleContexts, 
              FlexibleInstances, OverlappingInstances, UndecidableInstances
  #-}