Parse errors when parsing macOS system headers

[roboguy13]

I have recently noticed the issues in the title. There seem to be some syntax extensions involved which language-c does not appear to currently support.

A small example:

Contents of test.c:

#include <dirent.h>

Contents of Test.hs:

{-# LANGUAGE LambdaCase #-}

import           Language.C
import           Language.C.System.Preprocess
import           Language.C.System.GCC

main :: IO ()
main = do
  let gcc = newGCC "/usr/bin/gcc"
      fileName = "test.c"

  runPreprocessor gcc (cppFile fileName) >>= \case
    Left err -> putStrLn ("Preprocessor error: " ++ show err)

    Right preprocessed ->
      case parseC preprocessed (initPos fileName) of
        Left err -> putStrLn ("Parse error: " ++ show err)
        Right _ -> putStrLn "Success"

Executing runghc Test.hs in the same directory as test.c produces the following:

Parse error: /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include/dirent.h:159: (column 10) [ERROR]  >>> Syntax Error !
  Syntax error !
  The symbol `^' does not fit here.

The relevant line, and surrounding lines, in that header are these:

int scandir_b(const char *, struct dirent ***,
    int (^)(const struct dirent *) __scandir_noescape,         //  **** This is line 159  *****
    int (^)(const struct dirent **, const struct dirent **) __scandir_noescape)
    __DARWIN_INODE64(scandir_b) __OSX_AVAILABLE_STARTING(__MAC_10_6, __IPHONE_3_2);

I think this syntax extension is for blocks, but I haven't used that feature before.

[expipiplus1]

I'd happily merge a PR implementing support for these (afaict it's just an alternative to '*' on the syntax). At the least this could be mentioned in the readme. Is there some CPP directive you can use to disable these bits perhaps?

…

On Wed, 6 Oct 2021, 3:49 am David Young, ***@***.***> wrote: I have recently noticed the issues in the title. There seem to be some syntax extensions involved which language-c does not appear to currently support. A small example: Contents of test.c: #include <dirent.h> Contents of Test.hs: {-# LANGUAGE LambdaCase #-} import Language.C import Language.C.System.Preprocess import Language.C.System.GCC main :: IO () main = do let gcc = newGCC "/usr/bin/gcc" fileName = "test.c" runPreprocessor gcc (cppFile fileName) >>= \case Left err -> putStrLn ("Preprocessor error: " ++ show err) Right preprocessed -> case parseC preprocessed (initPos fileName) of Left err -> putStrLn ("Parse error: " ++ show err) Right _ -> putStrLn "Success" This produces the following: Parse error: /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include/dirent.h:159: (column 10) [ERROR] >>> Syntax Error ! Syntax error ! The symbol `^' does not fit here. The relevant line, and surrounding lines, in that header are these: int scandir_b(const char *, struct dirent ***, int (^)(const struct dirent *) __scandir_noescape, // **** This is line 159 ***** int (^)(const struct dirent **, const struct dirent **) __scandir_noescape) __DARWIN_INODE64(scandir_b) __OSX_AVAILABLE_STARTING(__MAC_10_6, __IPHONE_3_2); I think this syntax extension is for blocks <https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/Blocks/Articles/00_Introduction.html>, but I haven't used that feature before. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#85>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAGRJXCM7HKWZ2V3ZCYDZJDUFNJDZANCNFSM5FMPE3QA> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.