551782 - Move PR_STATIC_ASSERT from prlog.h to prtypes.h

Status: RESOLVED FIXED

(NSPR :: NSPR, defect)

Description

[Zack Weinberg (:zwol)]

Attachment: patch

PR_STATIC_ASSERT is wanted in code (e.g. headers) that doesn't want the side-effects of including prlog.h, so we move it to prtypes.h.

Comment 1

[(not currently active) Ted Mielczarek]

I landed this in CVS for you:
Checking in pr/include/prlog.h;
/cvsroot/mozilla/nsprpub/pr/include/prlog.h,v  <--  prlog.h
new revision: 3.18; previous revision: 3.17
done
Checking in pr/include/prtypes.h;
/cvsroot/mozilla/nsprpub/pr/include/prtypes.h,v  <--  prtypes.h
new revision: 3.42; previous revision: 3.41
done

Comment 2

[Zack Weinberg (:zwol)]

Thanks for landing the patch.  I presume we need to wait for the next NSPR code drop before we can start assuming PR_STATIC_ASSERT is in prtypes.h?

Comment 3

[(not currently active) Ted Mielczarek]

Correct.

Comment 4

[Wolfgang Rosenauer [:wolfiR]]

I marked that with TM 4.8.6 as this is the first RTM with that change AFAIK. Please correct if I'm wrong.

Comment 5

[Wan-Teh Chang]

Zack: What's the side effects of including prlog.h
that you don't want?

The reason PR_STATIC_ASSERT was defined in prlog.h
was that the similar PR_ASSERT macro (run-time
assertions) is defined in prlog.h.

Comment 6

[Zack Weinberg (:zwol)]

(In reply to comment #5)
> Zack: What's the side effects of including prlog.h
> that you don't want?

It decides whether PR_LOG is compiled in.  In some cases, we want to make that decision on a per-.cpp-file basis, *after* including many other headers.

Comment 7

[Wan-Teh Chang]

Zack: thanks for the explanation.  Let me confirm
my understanding with a concret example.

This seems to be what you described:

----- Begin Foo.cpp -----

#include "prtypes.h"

#include "header1.h"
#include "header2.h"

#if defined(CONDITION1)
#define FORCE_PR_LOG 1
#endif

#include "prlog.h"

#include "header3.h"
#include "header4.h"

// Actual C++ code

----- End Foo.cpp -----

If I understand you correctly, the CONDITION1
macro cannot be tested until you have included
header1.h and header2.h, but you want to use
PR_STATIC_ASSERT in header1.h and header2.h.

Is this correct?

Comment 8

[Zack Weinberg (:zwol)]

Yeah, that's my understanding of it.  I can't point you to any concrete cases in mozilla, though.