CODEWITHSUNDEEP
c++include
Sam
Sam

Reputation: 299

Struct included in two header files, neither of which I own

I am trying to play with SCHED_DEADLINE in c++, I needed to send struct sched_attr to and ioctl so I included <linux/sched/types.h>, that header also happens to include strut sched_param. I also included <string> which includes the standard headers for c++ which eventually includes include\bits\sched.h which also defines struct sched_param. The compiler (obviously) doesn't particularly like this. I used the header guard (_BITS_TYPES_STRUCT_SCHED_PARAM) in my code to get the compiler to not include include\bits\sched.h, but it feels like there should be a "better" way.

> Executing task in folder sched_deadline_testing: arm-linux-gnueabihf-g++ -o LSM9DS0 src/LSM9DS0.cpp -Wall --pedantic <

In file included from src/LSM9DS0.cpp:36:
/usr/arm-linux-gnueabihf/include/linux/sched/types.h:7:8: error: redefinition of ‘struct sched_param’
 struct sched_param {
        ^~~~~~~~~~~
In file included from /usr/arm-linux-gnueabihf/include/bits/sched.h:74,
                 from /usr/arm-linux-gnueabihf/include/sched.h:43,
                 from /usr/arm-linux-gnueabihf/include/pthread.h:23,
                 from /usr/arm-linux-gnueabihf/include/c++/8/arm-linux-gnueabihf/bits/gthr-default.h:35,
                 from /usr/arm-linux-gnueabihf/include/c++/8/arm-linux-gnueabihf/bits/gthr.h:148,
                 from /usr/arm-linux-gnueabihf/include/c++/8/ext/atomicity.h:35,
                 from /usr/arm-linux-gnueabihf/include/c++/8/bits/basic_string.h:39,
                 from /usr/arm-linux-gnueabihf/include/c++/8/string:52,
                 from src/LSM9DS0.cpp:20:
/usr/arm-linux-gnueabihf/include/bits/types/struct_sched_param.h:23:8: note: previous definition of ‘struct sched_param’
 struct sched_param

The code is here if that's important. I have also tried this cross compiling, and compiling locally, both cause the issue.

Upvotes: 1

Views: 520

Answers (1)

eerorika
eerorika

Reputation: 238301

You're out of luck. The two headers are incompatible. You simply must avoid including both <linux/sched/types.h> and <string> into the same translation unit. It's probably worth noting that being a Linux kernel header, the former is probably not intended to be used in C++, nor has there been an attempt to make it compatible.

Upvotes: 5

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