550401 - warning C4273: 'moz_strdup' : inconsistent dll linkage (string.h relating to mozalloc.h)

Status: VERIFIED FIXED

(Core :: XPCOM, defect)

Description

[Justin Wood (:Callek)]

C:\Program Files\Microsoft Visual Studio 8\VC\INCLUDE\string.h(207) : warning C4273: 'moz_strdup' : inconsistent dll linkage
c:\programming\objectdirs\mozilla\trunk\suiterunnerdebug\mozilla\dist\include\mozilla/mozalloc.h(138) : see previous definition of 'moz_strdup'

Per IRC with cjones, the issue is that the MSVC headers declare strdup as dllimport and we are dllexport.

Comment 1

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Since this code has been working with dllexport, I would assume that MSVC treats undefined dllexport functions as dllimport at link time, which makes me question the usefulness of dllimport.  But that's neither here nor there.

Comment 2

[timeless]

roughly you need a macro which results in DLL_EXPORT when used by mozalloc.cpp but DLL_IMPORT when included everywhere else. we have loads of macros for this.

Comment 3

[timeless]

Attachment: proposal

Comment 4

[Benjamin Smedberg]

Comment on attachment 430584 [details] [diff] [review]
proposal

+#  ifdef MOZALLOC_DONT_DEFINE_MACRO_WRAPPERS
+#    define MOZALLOC_METHOD __declspec(dllexport)
+#  else
+#    define MOZALLOC_METHOD __declspec(dllexport)
+#  endif

Pretty sure you meant one of this to be dllimport?

Comment 5

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Will that actually work with the system headers?  Along with that fix you might need to wrap the system headers like the WinCE build does (see build/wince/shunt, iirc), to do things like

#define strdup orig_strdup
#include <sdk_dir/string.h>
#undef strdup

Comment 7

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Attachment: Use dllimport/dllexport properly in libmozalloc

wfm on windows and linux.

Comment 8

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

bsmedberg, any chance of getting a quick review on this soonish?  Windows devs seem to be waiting with bated breath.

Comment 9

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

http://hg.mozilla.org/mozilla-central/rev/bbbb2d668d0d

Comment 10

[Serge Gautherie (:sgautherie)]

V.Fixed, per tinderbox.

(See bug 558163, just in case.)