Parameter Name Omitted, C++ VS C

Parameter name omitted error?

int box(int rows, int cols, int [rows][cols])

needs to be

int box(int rows, int cols, int something[rows][cols])

parameter name omitted, C++ vs C

No, in C you cannot omit identifiers for parameters in function definitions.

The C99 standard says:

[6.9.1.5] If the declarator includes a parameter type list, the
declaration of each parameter shall include an identifier, except for
the special case of a parameter list consisting of a single parameter
of type void, in which case there shall not be an identifier. No
declaration list shall follow.

The C++14 standard says:

[8.3.5.11] An identifier can optionally be provided as a parameter
name; if present in a function definition , it names a parameter
(sometimes called “formal argument”). [Note: In particular, parameter
names are also optional in function definitions and names used for a
parameter in different declarations and the definition of a function
need not be the same.]

C - Parameter Name Omitted?

Parameter Name Omitted

means, the compiler doesn't see a parameter name where it expects...

This is because you can't use define and a parameter name with the same name. When writing #define size 3 the pre-processor replaces each size it sees in the code with 3 and then, when you call a function with parameter size, instead of struct employee read_all_employee(..., int size), you get struct employee read_all_employee(..., int 3), resulting in an argument of type int with no valid name ('3' is not a valid name).

I would recommend using a define with CAPS, or with some unique name, so you won't get confused, like SIZE or just keep in mind that you have size symbol and use other parameter names in your function, such as input_size

Parameter name omitted in my function

You need to provide a name for the parameter.

void histogram(char y[N][M])

You can omit the name in a prototype declaration of a function, but not the definition.

You will also need to consider whether x is still needed, or whether the argument should be called x and the local variable deleted — I think that's likely what you need. But you also have to worry about count — where does that get initialized? It should probably be an extra parameter to the function. You should use putchar() to put single characters; it is best not to use printf() when there isn't a format string with at least one conversion specification in it.

void histogram(char x[][M], int count)
{
    for (int j = 0; j < count; j++)
    {
        int len = strlen(x[j]);
        for (int i = 0; i < len; i++)
            putchar('*');
        putchar('\n');
    }
}

Parameter name omitted (C)

The problem is in your function definition. LPVOID is a data type, while mentioning the parameter list in function definition, you need to have a paramater of that type, something like

UINT __stdcall StaffA(LPVOID p1)  // p1 is the parameter name, 
                                  // which you can use inside the function body
{
    while(Number1 < 100)
    {
        ...
    }
    return 0;
}

Same goes for the other function definition, too.

error: Parameter name omitted in C for structs

This isn't specific to structs.

In function prototypes (forward declarations), you are allowed to omit the name, e.g.

int foo(int, char*, struct student);

A forward declaration exists for callers of the function. So here, the compiler really only needs to know what type of parameters to expect. Considering that the prototype (often found in a header file) serves as documentation on how to call said function, I strongly recommend that you include the names. Otherwise, you're likely to get smacked by the dev across the hall!

Your confusion may come from the syntax struct student. Keep in mind that the type's name is both words here, struct student. You can't refer to it in any other way, unless you use a typedef.

However, the parameter name is required for the actual function definition. Otherwise, how would you refer to the parameter?!

int foo(int number, char* name, struct student record) {

}

I should also point out that it is rare that one actually wants to pass a struct (by value) to a function. More likely is the case that you pass a pointer to a struct:

int foo(int number, char* name, struct student *record_ptr) {

}

parameter name omitted error for function returning enum

"Parameter name omitted" is the error given by GCC-family compilers when (naturally) a parameter's name is omitted in a function definition, which is not permitted in C.

The latest Clang and GCC versions actually don't object to the declaration above (assuming definitions for struct hrtimer and enum hrtimer_restart), so my guess is you're not using one of them and are instead using a different compiler that isn't perfectly compliant with the C spec. The code in the question is correct and shouldn't be rejected.

If so, it's probably not recognising that the function name is allowed to be in parentheses, and has incorrectly parsed hrtimer_restart as the function name, and hr_toggle as the type of the first parameter (and ...hasn't got as far as noticing enum isn't a return type before giving up - weird order to do things).

Removing the parentheses from the name, or preferably changing your compiler/compiler's settings, to something more perfectly compliant, should deal with this.

Error: Parameter name omitted

finished is the name of the BOOL parameter, and Objective-C blocks have C-style function signatures, so it has to be in the parentheses.

The block's signature is supposed to look like this:

^(BOOL finished) {
}