Re: RFC - C99 issue regarding unnamed union/structs


Thomas Törnblom
 

While on the subject of language compliance, what about the frequent usage of non-standard gcc extensions that limits portability?

I've started looking at making IAR Embedded Workbench a supported tool chain for Zephyr, and while I have not looked at the cmake build tools yet, I've tried to build one of the examples (hello) using our IDE, and have run into several non-standard things like:

1) Empty structs (struct _caller_saved in kernel_arch_thread.h)

2) Packed structs, "struct __packed__ ..." vs "__packed struct .." or "struct __attribute__((__packed__)) ...", the latter two variants are accepted by our tools, the first is not ( _k_thread_stack_element in kernel.h)

3) Zero sized arrays (several places in the include files for logging)

4) Ellipses/ranges in case (printk.c)

5) alloca

Of these alloca() is probably the most problematic for us as we have no alloca, and no easy way to implement it either as we have no frame pointer. In one place I could use a variable size array, but the rb code requires more work, and I would really prefer not having to use the variable size array either.

Comments?

/Thomas

Den 2019-01-14 kl. 22:11, skrev Peter A. Bigot:

I don't have a solution, but since the question came up I am interested in any reaction to https://github.com/zephyrproject-rtos/zephyr/issues/9552#issuecomment-449718078 since that's relevant to the topic.

Peter

On 1/14/19 1:47 PM, Flavio Ceolin wrote:
Hi guys,

One problem with have in Zephyr regarding C99 is that we are using a lot
of unnamed struct/unions. One example is:




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Thomas Törnblom, Product Engineer
IAR Systems AB
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