-debug and -release

[Don Clugston]

Derek Parnell wrote:
> On Sun, 27 May 2007 14:15:13 -0400, lurker wrote:
> 
>> What does it mean to compile a file with -debug and -release switches? Like so:
>>
>> $ echo "void main() {}" > test.d
>> $ dmd -debug -release test.d
>>
>> Why the compiler accepts both and doesn't complaint?
> 
> The compiler accepts both because they are not opposites of each other,
> despite what one may think just knowing the English terms.
> 
> "-debug" functionality is almost exactly like the "-version" switch. It
> actually has nothing intrinsic to with debugging other than identifying
> sections of code as ones in which the author nominates, and thus presumably
> intends, to be debugging code. But the code can contain anything at all.
> These sections of code are brought into the compilation process in exactly
> the same way as sections identified using the version construct. In fact,
> one can use "version(XXX){}" and "debug(XXX){}" interchangeably. In other
> words ...
> 
>    debug(ABC) { ... }
> 
> is functionally identical to 
> 
>   version(ABC) { ... }
> 
> The purpose of using "debug" rather than "version" is just to highlight to
> readers of the source code the sections that are intended to be debugging
> stuff. There is nothing 'magic' about "-debug".

> 
> "-release" controls whether or not built-in and user-defined checks are
> excluded from the compilation. If you do not have "-release" the compiler
> adds array bounds checking, assert() functionality, invariant blocks in
> classes, and in/out blocks in functions. If you use "-release" such
> functionality is ignored by the compiler. Presumably the name "release" is
> being associated with the desire to remove time consuming run time checks
> in a program that has been debugged and is ready now for production
> release.

Maybe something like -nochecks would be a better name for -release.
At least, the command line description should change
   -quiet         suppress unnecessary messages
   -release       compile release version

That's really not helpful!

How about:
   -release       do not generate runtime checks

I only just discovered that assert(0) is _not_ disabled by -release. I 
didn't find that mentioned in the documentation.