ghc package does not have to depend on terminfo

cabal.project-reinstall

@@ -48,7 +48,7 @@ packages: ./compiler
           ./utils/iserv
           ./linters/**/*.cabal
 
-constraints: ghc +internal-interpreter +dynamic-system-linke +terminfo,
+constraints: ghc +internal-interpreter +dynamic-system-linke,
              ghc-bin +internal-interpreter +threaded,
              ghci +internal-interpreter,
              haddock +in-ghc-tree,

compiler/GHC/SysTools/Terminal.hs

@@ -4,16 +4,11 @@ module GHC.SysTools.Terminal (stderrSupportsAnsiColors) where
 
 import GHC.Prelude
 
-#if defined(MIN_VERSION_terminfo)
-import GHC.IO (catchException)
-import Data.Maybe (fromMaybe)
-import System.Console.Terminfo (SetupTermError, Terminal, getCapability,
-                                setupTermFromEnv, termColors)
-import System.Posix (queryTerminal, stdError)
-#elif defined(mingw32_HOST_OS)
+#if !defined(mingw32_HOST_OS)
+import System.IO (hIsTerminalDevice, stderr)
+#else
 import GHC.IO (catchException)
 import GHC.Utils.Exception (try)
--- import Data.Bits ((.|.), (.&.))
 import Foreign (Ptr, peek, with)
 import qualified Graphics.Win32 as Win32
 import qualified System.Win32 as Win32
@@ -40,18 +35,10 @@ stderrSupportsAnsiColors = unsafePerformIO stderrSupportsAnsiColors'
 -- | Check if ANSI escape sequences can be used to control color in stderr.
 stderrSupportsAnsiColors' :: IO Bool
 stderrSupportsAnsiColors' = do
-#if defined(MIN_VERSION_terminfo)
-    stderr_available <- queryTerminal stdError
-    if stderr_available then
-      fmap termSupportsColors setupTermFromEnv
-        `catchException` \ (_ :: SetupTermError) -> pure False
-    else
-      pure False
-  where
-    termSupportsColors :: Terminal -> Bool
-    termSupportsColors term = fromMaybe 0 (getCapability term termColors) > 0
-
-#elif defined(mingw32_HOST_OS)
+#if !defined(mingw32_HOST_OS)
+    -- Coloured text is a part of ANSI standard, no reason to query terminfo
+    hIsTerminalDevice stderr
+#else
   h <- Win32.getStdHandle Win32.sTD_ERROR_HANDLE
          `catchException` \ (_ :: IOError) ->
            pure Win32.nullHANDLE
@@ -100,6 +87,4 @@ foreign import WINAPI unsafe "windows.h GetConsoleMode" c_GetConsoleMode
 foreign import WINAPI unsafe "windows.h SetConsoleMode" c_SetConsoleMode
   :: Win32.HANDLE -> Win32.DWORD -> IO Win32.BOOL
 
-#else
-   pure False
 #endif

compiler/ghc.cabal.in

@@ -46,11 +46,6 @@ Flag internal-interpreter
     Default: False
     Manual: True
 
-Flag terminfo
-    Description: Build GHC with terminfo support on non-Windows platforms.
-    Default: True
-    Manual: True
-
 Flag dynamic-system-linker
     Description: The system can load dynamic code. This is not the case for musl.
     Default: True
@@ -98,8 +93,6 @@ Library
     if os(windows)
         Build-Depends: Win32  >= 2.3 && < 2.14
     else
-        if flag(terminfo)
-            Build-Depends: terminfo == 0.4.*
         Build-Depends: unix   >= 2.7 && < 2.9
 
     GHC-Options: -Wall

hadrian/src/Rules/ToolArgs.hs

@@ -172,7 +172,7 @@ toolTargets = [ binary
               , text
               , transformers
               , unlit  -- # executable
-              ] ++ if windowsHost then [ win32 ] else [ terminfo, unix ]
+              ] ++ if windowsHost then [ win32 ] else [ unix ]
 
 -- | Create a mapping from files to which component it belongs to.
 dirMap :: Action [(FilePath, (Package, [String]))]

hadrian/src/Settings/Packages.hs

@@ -89,7 +89,6 @@ packageArgs = do
 
           , builder (Cabal Flags) ? mconcat
             [ andM [expr ghcWithInterpreter, notStage0] `cabalFlag` "internal-interpreter"
-            , notM cross `cabalFlag` "terminfo"
             , ifM stage0
                   -- We build a threaded stage 1 if the bootstrapping compiler
                   -- supports it.