[Lori Jakab <lorand.jakab@xxxxxxxxx>]

Hi,

I'm have been building on macOS Mojave for a while without issues, but for the last few days the build has been broken. I didn't try a git dissect yet to see which commit broke it, but the issue seems to be caused by the usage of the _Nonnull, _Nullable, or _Null_unspecified type specifiers in the 6lowpan dissector.

My compiler is:

> gcc --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
Apple clang version 11.0.0 (clang-1100.0.33.17)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

This is the error: 

In file included from /Users/lojakab/src/wireshark-lisp/wireshark/epan/dissectors/packet-6lowpan.c:19:
In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:64:
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:93:16: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
        unsigned char   *_base;
                        ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:93:16: note: insert '_Nullable' if the pointer may be null
        unsigned char   *_base;
                        ^
                          _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:93:16: note: insert '_Nonnull' if the pointer should never be null
        unsigned char   *_base;
                        ^
                          _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:138:32: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
        int     (* _Nullable _read) (void *, char *, int);
                                          ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:138:32: note: insert '_Nullable' if the pointer may be null
        int     (* _Nullable _read) (void *, char *, int);
                                          ^
                                           _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:138:32: note: insert '_Nonnull' if the pointer should never be null
        int     (* _Nullable _read) (void *, char *, int);
                                          ^
                                           _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:138:40: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
        int     (* _Nullable _read) (void *, char *, int);
                                                  ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:138:40: note: insert '_Nullable' if the pointer may be null
        int     (* _Nullable _read) (void *, char *, int);
                                                  ^
                                                   _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:138:40: note: insert '_Nonnull' if the pointer should never be null
        int     (* _Nullable _read) (void *, char *, int);
                                                  ^
                                                   _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:139:35: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
        fpos_t  (* _Nullable _seek) (void *, fpos_t, int);
                                          ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:139:35: note: insert '_Nullable' if the pointer may be null
        fpos_t  (* _Nullable _seek) (void *, fpos_t, int);
                                          ^
                                           _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:139:35: note: insert '_Nonnull' if the pointer should never be null
        fpos_t  (* _Nullable _seek) (void *, fpos_t, int);
                                          ^
                                           _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:140:32: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
        int     (* _Nullable _write)(void *, const char *, int);
                                          ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:140:32: note: insert '_Nullable' if the pointer may be null
        int     (* _Nullable _write)(void *, const char *, int);
                                          ^
                                           _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:140:32: note: insert '_Nonnull' if the pointer should never be null
        int     (* _Nullable _write)(void *, const char *, int);
                                          ^
                                           _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:140:46: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
        int     (* _Nullable _write)(void *, const char *, int);
                                                        ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:140:46: note: insert '_Nullable' if the pointer may be null
        int     (* _Nullable _write)(void *, const char *, int);
                                                        ^
                                                         _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:140:46: note: insert '_Nonnull' if the pointer should never be null
        int     (* _Nullable _write)(void *, const char *, int);
                                                        ^
                                                         _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:144:18: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
        struct __sFILEX *_extra; /* additions to FILE to not break ABI */
                        ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:144:18: note: insert '_Nullable' if the pointer may be null
        struct __sFILEX *_extra; /* additions to FILE to not break ABI */
                        ^
                          _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/_stdio.h:144:18: note: insert '_Nonnull' if the pointer should never be null
        struct __sFILEX *_extra; /* additions to FILE to not break ABI */
                        ^
                          _Nonnull
In file included from /Users/lojakab/src/wireshark-lisp/wireshark/epan/dissectors/packet-6lowpan.c:19:
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:67:13: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
extern FILE *__stdinp;
            ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:67:13: note: insert '_Nullable' if the pointer may be null
extern FILE *__stdinp;
            ^
              _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:67:13: note: insert '_Nonnull' if the pointer should never be null
extern FILE *__stdinp;
            ^
              _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:390:41: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
                 int (* _Nullable)(void *, const char *, int),
                                        ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:390:41: note: insert '_Nullable' if the pointer may be null
                 int (* _Nullable)(void *, const char *, int),
                                        ^
                                         _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:390:41: note: insert '_Nonnull' if the pointer should never be null
                 int (* _Nullable)(void *, const char *, int),
                                        ^
                                         _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:390:55: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
                 int (* _Nullable)(void *, const char *, int),
                                                      ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:390:55: note: insert '_Nullable' if the pointer may be null
                 int (* _Nullable)(void *, const char *, int),
                                                      ^
                                                       _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:390:55: note: insert '_Nonnull' if the pointer should never be null
                 int (* _Nullable)(void *, const char *, int),
                                                      ^
                                                       _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:391:44: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
                 fpos_t (* _Nullable)(void *, fpos_t, int),
                                           ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:391:44: note: insert '_Nullable' if the pointer may be null
                 fpos_t (* _Nullable)(void *, fpos_t, int),
                                           ^
                                            _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:391:44: note: insert '_Nonnull' if the pointer should never be null
                 fpos_t (* _Nullable)(void *, fpos_t, int),
                                           ^
                                            _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:392:41: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
                 int (* _Nullable)(void *));
                                        ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:392:41: note: insert '_Nullable' if the pointer may be null
                 int (* _Nullable)(void *));
                                        ^
                                         _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:392:41: note: insert '_Nonnull' if the pointer should never be null
                 int (* _Nullable)(void *));
                                        ^
                                         _Nonnull
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:388:6: error: pointer is missing a nullability type specifier
      (_Nonnull, _Nullable, or _Null_unspecified) [-Werror,-Wnullability-completeness]
FILE    *funopen(const void *,
        ^
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:388:6: note: insert '_Nullable' if the pointer may be null
FILE    *funopen(const void *,
        ^
          _Nullable
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:388:6: note: insert '_Nonnull' if the pointer should never be null
FILE    *funopen(const void *,
        ^
          _Nonnull

3 errors generated.
make[2]: *** [epan/dissectors/CMakeFiles/dissectors.dir/packet-6lowpan.c.o] Error 1
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [epan/dissectors/CMakeFiles/dissectors.dir/all] Error 2

This code builds on Linux, and I assume some older version of macOS on the buildbots too. Should I give it a go to fixing this? I'm not the 6lowpan dissector author/maintainer.

-Lori