David Eichmann pushed to branch wip/davide/ghc-toolchain-throw-less at Glasgow Haskell Compiler / GHC Commits: 9e4fc6a5 by David Eichmann at 2026-06-11T15:37:32+01:00 ghc-toolchain: don't throw when candidate executables are not found Fixes #27369 - - - - - 2 changed files: - utils/ghc-toolchain/src/GHC/Toolchain/Program.hs - utils/ghc-toolchain/src/GHC/Toolchain/Utils.hs Changes: ===================================== utils/ghc-toolchain/src/GHC/Toolchain/Program.hs ===================================== @@ -148,12 +148,14 @@ findProgram description userSpec candidates Just prefix -> map (prefix++) candidates Nothing -> [] candidates' = prefixedCandidates ++ candidates - err = - [ "Failed to find " ++ description ++ "." - , "Looked for one of " ++ show candidates' ++ " in the system search path." - ] - path <- oneOf' err (map findExecutableErr candidates') - return Program { prgPath = path, prgFlags = fromMaybe [] (poFlags userSpec) } + pathMay <- findM doesExecutableExist candidates' + case pathMay of + Nothing -> throwEs + [ "Failed to find " ++ description ++ "." + , "Looked for one of " ++ show candidates' ++ " in the system search path." + ] + Just path -> + return Program { prgPath = path, prgFlags = fromMaybe [] (poFlags userSpec) } -- Note that @configure.ac@ checks these llvm version constants (using @sed@) to -- ensure they are the same as the @$LlvmMinVersion@ and @$LlvmMaxVersion@ @@ -222,21 +224,19 @@ maybeFindProgramFromProgOpts :: String -> ProgOpt -> Maybe (M Program) maybeFindProgramFromProgOpts description userSpec = case poPath userSpec of Nothing -> Nothing Just path -> Just $ do - let err = - [ "Failed to find " ++ description ++ "." - , "Looked for user-specified program '" ++ path ++ "' in the system search path." - ] - path' <- findExecutableErr path <|> throwEs err - return Program { prgPath = path', prgFlags = fromMaybe [] (poFlags userSpec) } - -findExecutableErr :: String -> M FilePath -findExecutableErr name = do - r <- liftIO $ findExecutable name - case r of - Nothing -> throwE $ name ++ " not found in search path" - -- Use the given `prgPath` or candidate name rather than the - -- absolute path returned by `findExecutable`. - Just _x -> return name + exists <- doesExecutableExist path + unless exists $ throwEs + [ "Failed to find " ++ description ++ "." + , "Looked for user-specified program '" ++ path ++ "' in the system search path." + ] + return Program { prgPath = path, prgFlags = fromMaybe [] (poFlags userSpec) } + +-- | Returns the first condidate that exists (can ) +doesExecutableExist + :: String -- ^ executable name + -> M Bool +doesExecutableExist name = isJust <$> liftIO (findExecutable name) + -------------------- Compiling utilities -------------------- ===================================== utils/ghc-toolchain/src/GHC/Toolchain/Utils.hs ===================================== @@ -9,6 +9,7 @@ module GHC.Toolchain.Utils , oneOf' , isSuccess , lastLine + , findM ) where import Control.Exception @@ -69,3 +70,10 @@ isSuccess = \case lastLine :: String -> String lastLine = maybe "" snd . unsnoc . lines + +findM :: Monad m => (a -> m Bool) -> [a] -> m (Maybe a) +findM f = \case + [] -> return Nothing + a:as -> do + found <- f a + if found then return (Just a) else findM f as View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/9e4fc6a5ed9a42dd6e1cd0c3cc7ebf90... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/9e4fc6a5ed9a42dd6e1cd0c3cc7ebf90... You're receiving this email because of your account on gitlab.haskell.org.