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RE: Problems with #import <stdarg.h>
- From: "John (Eljay) Love-Jensen" <eljay at adobe dot com>
- To: Ronald Pijnacker <pijnacker at dse dot nl>, "gcc-help at gcc dot gnu dot org" <gcc-help at gcc dot gnu dot org>
- Date: Thu, 23 Jul 2009 06:27:46 -0700
- Subject: RE: Problems with #import <stdarg.h>
- References: <20090723103920.GA25570@asus>
Hi Ronald,
I believe* all the operating system provided headers (such as the Standard C Library ones) expected to be #include'd (which uses the C protocol for the preprocessor), not #import'd (the ObjC protocol for the preprocessor).
Using #import can interfere with their multi-include logic. The reason for the multi-include logic is historical/legacy, evolutionary, backwards compatibility, and also involves ISO 9899 standardization (both 1989 and 1999). And for some headers, which are more intimately tied to the operating system than the Standard C Library, there may be some POSIX (IEEE Std 1003) contortions as well or UNIX 2003 contortions. It's hard to please everyone.
In theory, they could be made to be #import savvy as well, but those headers are really C headers, not ObjC headers. (Often they have allowances incorporated to be used as-is for C++. But C++ compilation units really should use <cstdarg> and <cstdio> rather than the raw C <stdarg.h> and <stdio.h> anyway.)
HTH,
--Eljay
* I may be mistaken.