Fix parsing of rpaths which include spaces in runInjectRPaths

The logic didn't account for the fact that the paths could contain
spaces before which led to errors such as the following from
install_name_tool.

Stderr ( T14304 ):
Warning: -rtsopts and -with-rtsopts have no effect with -shared.
    Call hs_init_ghc() from your main() function to set these options.
error: /nix/store/a6j5761iy238pbckxq2xrhqr2d5kra4m-cctools-binutils-darwin-949.0.1/bin/install_name_tool: for: dist/build/libHSp-0.1-ghc8.10.6.dylib (for architecture arm64) option "-add_rpath /Users/matt/ghc/bindisttest/install   dir/lib/ghc-8.10.6/ghc-prim-0.6.1" would duplicate path, file already has LC_RPATH for: /Users/matt/ghc/bindisttest/install   dir/lib/ghc-8.10.6/ghc-prim-0.6.1
`install_name_tool' failed in phase `Install Name Tool'. (Exit code: 1)

Fixes #20212

compiler/main/SysTools/Tasks.hs

@@ -18,6 +18,8 @@ import GHC.Platform
 import Util
 
 import Data.List
+import Data.Char
+import Data.Maybe
 
 import System.IO
 import System.Process
@@ -28,9 +30,10 @@ import LlvmCodeGen.Base (LlvmVersion, llvmVersionStr, supportedLlvmVersionLowerB
 import SysTools.Process
 import SysTools.Info
 
-import Control.Monad (join, forM, filterM)
+import Control.Monad (join, forM, filterM, void)
 import System.Directory (doesFileExist)
 import System.FilePath ((</>))
+import Text.ParserCombinators.ReadP as Parser
 
 {-
 ************************************************************************
@@ -267,10 +270,9 @@ runInjectRPaths dflags lib_paths dylib = do
   -- filter the output for only the libraries. And then drop the @rpath prefix.
   let libs = fmap (drop 7) $ filter (isPrefixOf "@rpath") $ fmap (head.words) $ info
   -- find any pre-existing LC_PATH items
-  info <- fmap words.lines <$> askOtool dflags Nothing [Option "-l", Option dylib]
-  let paths = concatMap f info
-        where f ("path":p:_) = [p]
-              f _            = []
+  info <- lines <$> askOtool dflags Nothing [Option "-l", Option dylib]
+
+  let paths = mapMaybe get_rpath info
       lib_paths' = [ p | p <- lib_paths, not (p `elem` paths) ]
   -- only find those rpaths, that aren't already in the library.
   rpaths <- nub.sort.join <$> forM libs (\f -> filterM (\l -> doesFileExist (l </> f)) lib_paths')
@@ -279,6 +281,24 @@ runInjectRPaths dflags lib_paths dylib = do
     [] -> return ()
     _  -> runInstallNameTool dflags $ map Option $ "-add_rpath":(intersperse "-add_rpath" rpaths) ++ [dylib]
 
+get_rpath :: String -> Maybe FilePath
+get_rpath l = case readP_to_S rpath_parser l of
+                [(rpath, "")] -> Just rpath
+                _ -> Nothing
+
+
+rpath_parser :: ReadP FilePath
+rpath_parser = do
+  skipSpaces
+  void $ string "path"
+  void $ many1 (satisfy isSpace)
+  rpath <- many get
+  void $ many1 (satisfy isSpace)
+  void $ string "(offset "
+  void $ munch1 isDigit
+  void $ Parser.char ')'
+  skipSpaces
+  return rpath
 
 runLink :: DynFlags -> [Option] -> IO ()
 runLink dflags args = traceToolCommand dflags "linker" $ do