What is the difference between flexible array and varying array?

[ujos]

What is the difference between flexible array and varying array?

[burlachenkok]

I have added C99 standard and description what is flexible array. It's a popular thing used pretty often in any kernel code for Windows and Linux.

Thanks for reference, such as:
https://wiki.sei.cmu.edu/confluence/display/c/DCL38-C.+Use+the+correct+syntax+when+declaring+a+flexible+array+member

But I try to use standards, when it's enough.

Support of varying array array. - is a misprint..

[ujos]

Ok, now it is more clear, however still I do not understand what is purpose of the [*]. MSVC does not support it. GCC does support but in the function prototype only. What is the difference between these below:

void foo(int arr[], size_t arrSize);
void bar(int arr[*], size_t arrSize);

[ujos]

If the size is not present, the array type is an incomplete type. If the size is * instead of
being an expression, the array type is a variable length array type of unspecified size,
which can only be used in declarations with function prototype scope;122) such arrays are
nonetheless complete types.

Now the question is what is incomplete type

BTW, variable length array is also array of size that is not const value:

int z = 5;
int arr[z]; // << variable length array

[burlachenkok]

> void foo(int arr[], size_t arrSize);
> void bar(int arr[*], size_t arrSize);
> ```

- I have added incompleted type information into the glossary
- I have updated the variable-length array description
- I have removed a variable-length array that is confusing [*] notation.

> What is the difference between these below?

I don't know. I thought construction with `[*]` allows to have an incomplete type, but it's not the case.
(In experiments with `gcc -x c --std=c99` through https://godbolt.org/). For me both foo and bar is identical and nothing special I see inside https://godbolt.org/.