[Issue 23441] New: importc: array length macro preprocessed with cpp doesn't compile

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=23441

          Issue ID: 23441
           Summary: importc: array length macro preprocessed with cpp
                    doesn't compile
           Product: D
           Version: D2
          Hardware: x86_64
                OS: All
            Status: NEW
          Severity: blocker
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: ryuukk.dev at gmail.com

The following code:

```
--- test.d
import bar;
void main()
{
    int len;
    foo(&len);
}

--- bar.c
struct nk_utfmask
{ int test; };

void foo(int* i)
{   
    // #define NK_LEN(a) (sizeof(a)/sizeof(a)[0])
    // for(*i = 0; *i < (int)NK_LEN(nk_utfmask); ++(*i))
    // expended using `cpp -E` on linux
    //
    for(*i = 0; *i < (int)(sizeof(nk_utfmask)/sizeof(nk_utfmask)[0]); ++(*i)) {
    }
}
```

Error:

bar.c(10): Error: found `[` when expecting `)`
bar.c(10): Error: found `0` when expecting `;` following `for` condition
bar.c(10): Error: expression expected, not `]`
bar.c(10): Error: found `)` when expecting `;` following statement


Apparently it's not valid C11, but that's the preprocessor output, so i'm not
sure what i should do, i lack understanding on the syntax itself unfortunately

--