On Sun, Sep 23, 2012 at 6:10 PM, Guy Harris <g...@alum.mit.edu> wrote: > > On Sep 23, 2012, at 1:59 PM, Evan Huus <eapa...@gmail.com> wrote: > >> Variadic macros are forbidden in doc/README.developer since apparently >> not all compilers support them. >> >> However, I just stumbled across a variadic macro that has apparently >> been part of the regular build since around 2009 >> (packet-dcerpc-netlogon.c:65). >> >> Since nobody (to my knowledge) has complained about a failing build in >> that time period, I have to assume that whatever ancient compiler >> didn't support them is no longer being used. > > They're supported with Microsoft's compilers at least as far back as Visual > Studio 2005: > > http://msdn.microsoft.com/en-us/library/ms177415(v=vs.80).aspx > > There's no earlier version of the documentation offered by the "Other > Versions" dropdown, but I don't know whether that means "earlier compilers, > such as MSVC 6, didn't support them" or "we don't have the MSVC 6 > documentation online". This page: > > > http://bytes.com/topic/c/answers/220087-macros-variable-parameter-list-ms-vc-compiler-6-0-a > > has a claim that MSVC 6 didn't support variadic macros. If that's the case, > I don't personally have a problem with kicking MSVC 6 to the curb; we may > already have done so in the documentation, as > > http://www.wireshark.org/docs/wsdg_html_chunked/ChToolsMSChain.html > > only mentions it when it says "The official Wireshark 1.8.x releases are > compiled using Microsoft Visual C++ 2010 SP1. The official 1.2, 1.4, and 1.6 > releases are and were compiled using Microsoft Visual C++ 2008 SP1. Other > past releases, including the 1.0 branch, were compiled using Microsoft Visual > C++ 6.0.", and doesn't at all discuss using MSVC++ 6. > > I don't know what other compilers, such as Sun C^WOracle Solaris Studio, HP's > ANSI C compiler, or IBM's XL C support. My *guess* is that older versions of > those compilers may not have supported them but that they've all up-to-date > with C99 features. > > Sun C fully supported C99 as of Sun Studio 12 (not to be confused with Sun > Studio, Memphis :-)): > > http://docs.oracle.com/cd/E19205-01/820-4155/c.html#about > > *if* you specify -xc99; I don't know whether it or later versions support > variadic macros without -xc99 or whether earlier versions supported them. > > IBM C for AIX fully supported C99 as of V6.0 in 2002: > > > http://www-01.ibm.com/common/ssi/cgi-bin/ssialias?infotype=an&subtype=ca&supplier=897&appname=IBMLinkRedirect&letternum=ENUS202-161 > > and XL C for AIX > > http://www-01.ibm.com/software/awdtools/xlcpp/aix/features/ > > supports C99 now (with no indication in the document of when it started, but > the Wikipedia page for C99, whence I got these references, says it started > with V11.1). I don't know whether either of them have separate C89 and C99 > modes (which they might, for the benefit of those developing code that needs > to build on C89 compilers) or whether, in C89 mode, they support extensions > such as variadic macros. Given that one of IBM's compilers is the reason why > we ban // comments - it disallows them by default - I suspect that, when not > running in C99 (or C11?) mode, they do not support them. > > The HP ANSI C compiler supports C99 at least as of A.06.25 > > > http://h21007.www2.hp.com/portal/download/files/unprot/aCxx/Online_Help/getstarted.htm > > I don't know whether it has separate C89 and C99 modes (which they might, for > the benefit of those developing code that needs to build on C89 compilers) or > whether, in C89 mode, it supports extensions such as variadic macros. > >> P.S. Are there any other C99 features that we forbid that are actually >> supported by supposedly C89-only compilers like MSVC? > > // comments are, I think, supported by MSVC; I don't know whether any UN*X C > compilers support them without being told to run in C99 or C11 (or "GCC > compatible"?) mode. > > Turning on "full C99" mode for compilers does run the risk of people using > C99 features *not* supported by MSVC++ and not having them discovered until > the build breaks.
I'll leave the README unchanged for the moment then. Just out of curiosity, has anyone ever tried compiling on Windows with something like MinGW or another compiler? I expect there would be some initial pain, but if it allows us to drop MSVC and properly move to C99, I think would be an overall win. Evan ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev@wireshark.org> Archives: http://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-requ...@wireshark.org?subject=unsubscribe
