MacOS compilation about plug

[offa]

Seems these targets need some more work.

[j824h]

Thanks!
Adding target_link_libraries worked with the right target specified. (237-libusb...j824h:plug:patch-1)

[offa]

CMake seems to find libusb correctly, so I wonder why the include is missing. Can you check whether the CMake variable libusb-1.0_INCLUDE_DIR points to a valid path containing libusb-1.0/libusb.h?

I'm also getting a ton of errors about old-style-casting and unsigned-conversions, which I've ignored using make -i

Do these warning come from a library header or plug? Clang should handle system includes correctly, but I have not experience on Mac OS.

[j824h]

I had to add
include_directories(/usr/local/include)
in src/com/CMakeLists.txt, so that CMake can find libusb-1.0 installed by Homebrew.

Also for the root CMakeLists.txt, I found disabling -pedantic, -pedantic-errors, -Wold-style-cast helps.

[offa]

What does your libusb-1.0_INCLUDE_DIR show?

Regarding warnings: Did compilation fail otherwise? What errors are shown? CI builds include Clang too, but only on Linux.

[j824h]

Include errors

-- Found libusb-1.0: /usr/local/Cellar/libusb/1.0.26/lib/libusb-1.0.dylib
I see that libusb-1.0_INCLUDE_DIR is /usr/local/include.

Still, make would complain.

/Users/j824h/Documents/plug/src/com/UsbComm.cpp:25:10: fatal error: 'libusb-1.0/libusb.h' file not found

Syntax errors

After include_directories(/usr/local/include), the errors come from the header.

In file included from /Users/j824h/Documents/plug/src/com/UsbComm.cpp:25:
/usr/local/include/libusb-1.0/libusb.h:168:15: error: use of old-style cast [-Werror,-Wold-style-cast]
_tmp.b8[1] = (uint8_t) (x >> 8);
^ ~~~~~~~~
/usr/local/include/libusb-1.0/libusb.h:169:15: error: use of old-style cast [-Werror,-Wold-style-cast]
_tmp.b8[0] = (uint8_t) (x & 0xff);
^ ~~~~~~~~~~
/usr/local/include/libusb-1.0/libusb.h:789:31: error: zero size arrays are an extension [-Werror,-Wzero-length-array]
uint8_t dev_capability_data[ZERO_SIZED_ARRAY];

... and so on.

Clang correctly cast errors for the non-C++ syntax in libusb.h, according to the flags provided in CMakeLists.txt
In the other way round, I started to wonder why CI could build.

[offa]

Still, make would complain.

But /usr/local/include contains libusb-1.0/libusb.h!? Well … than there's something broken here.

Relying on PkgConfig not supported on Mac?

Clang correctly cast errors for the non-C++ syntax in libusb.h, according to the flags provided in CMakeLists.txt
In the other way round, I started to wonder why CI could build.

Yes and no, the reported issues come from an external library (libusb) and those are treated as system headers, which aren't affected by warnings etc..

Including through include_directories() wont do this, but rather treat the headers as usual. You can test this (not a solution!):

include_directories(SYSTEM /usr/local/include)

I'm not sure whether this works on Mac Clang though.

To sum it up: Findlibusb-1.0.cmake isn't working correctly here (--> include not found).

[offa]

Can you try the 237-libusb_missing_header branch please? 🤦

[j824h]

Clang correctly cast errors for the non-C++ syntax in libusb.h, according to the flags provided in CMakeLists.txt
In the other way round, I started to wonder why CI could build.

Yes and no, the reported issues come from an external library (libusb) and those are treated as system headers, which aren't affected by warnings etc..

Including through include_directories() wont do this, but rather treat the headers as usual. You can test this (not a solution!):

include_directories(SYSTEM /usr/local/include)

I'm not sure whether this works on Mac Clang though.

To sum it up: Findlibusb-1.0.cmake isn't working correctly here (--> include not found).

Oh, thanks for the clarification! (I got much left to know about this CMake...)

include_directories(SYSTEM /usr/local/include)

For now, adding this is all I need to build.

Can you try the 237-libusb_missing_header branch please? 🤦

I will keep tracking this!
Now make moves on to other targets referring to libusb.h and gives errors there.

[offa]

Thanks, so I can merge the branch. What are the other targets / errors?

[j824h]

• plug-communication-usb
  • UsbContext.cpp
  • UsbException.cpp
  • UsbDevice.cpp
• plug-updater
  • MustangUpdater.cpp

All of those, excluding the tests.

[offa]

Next try: 237-libusb – both targets link libusb on this branch now.

[offa]

Great! Since you have the change already, could you submit a PR please?

[offa]

Changes merged into master. Are there any build issues left?

[j824h]

In a Homebrew environment, there's a subtlety, that Qt5_DIR=/usr/local/opt/qt5/lib/cmake/Qt5 should be passed to CMake.
I do think the blame is on the package manager's choice not to install Qt in a default path.
Otherwise, 8d93d21 is working great with libusb-1.0 and googletest installed by Homebrew on MacOS.

[offa]

I'm going to close here since compilation works now. Feel free to reopen if there's an issue left. Thanks 👍