GitLab

b9784bd6

by Sven Tennie at 2026-03-25T14:54:14+01:00

Only add flags if they are new

This prevents duplicated when the user already set the arguments in
CXXFLAGS or CFLAGS.

@@ -61,7 +61,7 @@ findHsCpp progOpt cc = checking "for Haskell C preprocessor" $ do
    let rawHsCppProgram = addFlagIfNew "-E" foundHsCppProg
    -- Always try to add the Haskell-specific CPP flags, regardless of the user options
    hppArgs <- findHsCppArgs rawHsCppProgram
 -  let hsCppProgram = over _prgFlags (++hppArgs) rawHsCppProgram
 +  let hsCppProgram = foldr addFlagIfNew rawHsCppProgram (reverse hppArgs)
    return HsCpp{hsCppProgram}
  -- | Given a C preprocessor, figure out how it should be invoked to preprocess

@@ -383,7 +383,7 @@ addOSMinGW32CcFlags archOs cc link
  -- See Note [Windows stack allocations].
  checkFStackCheck :: Cc -> Program -> M Program
  checkFStackCheck cc link = checking "that -fstack-check works" $ do
 -      let link' = link & _prgFlags %++ "-fstack-check"
 +      let link' = addFlagIfNew "-fstack-check" link
        checkLinkWorks cc link'
        return link'
@@ -393,7 +393,7 @@ addNoAsNeeded archOs cc ccLink
    | os <- archOS_OS archOs
    , osElfTarget os
    = checking "that --no-as-needed works" $ do
 -      let ccLink' = over _prgFlags (++["-Wl,--no-as-needed"]) ccLink
 +      let ccLink' = addFlagIfNew "-Wl,--no-as-needed" ccLink
        checkLinkWorks cc ccLink'
        return ccLink'
    | otherwise = return ccLink