[Zlib-devel] TR: the win32\Makefile.msc diff

[Jonathan Nieder]

William A. Rowe Jr. wrote:
>>> On 3/21/2010 4:22 PM, Enrico Weigelt wrote:

>>>> But you can make the compiler fail if sizeof(..) doesnt match a
>>>> specific size, so use for a compile-test (in ./configure).
[...]
> But is this a compile-time fail or a runtime fail?

It fails at compile time.  You can declare an array like this:

 int dummy[(sizeof(z_off64_t) != 8) ? -1 : 1];

sizeof(z_off64_t) is a compile-time constant, and as long as it is 8,
this is valid C, declaring a one-element array.  If it is not 8, then
this code fails to compile.

It’s an old trick.  I doubt it originated with the Linux kernel.