Am 16.01.2013 11:11, schrieb Gert Doering: > Hi, > > On Tue, Jan 15, 2013 at 09:03:07PM +0200, Athanasios Douitsis wrote: >> Trying to compile 2.3 with visual studio 2010. I am getting the following >> error: >> >> init.c(186): error C2143: syntax error : missing ';' before 'type' >> [C:\openvpn4\openvpn-build\msvc\build.tmp\openvpn-2.3_master\src\openvpn\openvpn.vcxproj] >> >> (after that there are many many more errors, but you get the idea) > > Oh well, we've done it again...
User reply follows, Developer reply after next quote: Arguably, Visual Studio is broken if it does not accept the then-current version of ISO 9899, which would have been C99 for anything except VS2012 that should support C11, but reality differs, and <http://stackoverflow.com/questions/146381/visual-studio-support-for-new-c-c-standards> contains a few links to official info. If something has really failed to catch on with many commercial compilers, then I fear C99 is to carry this red light. :-( If the code is really type-safe and -clean in C++ terms, you may have some success with convincing VS to compile in C++ mode - but this needs typecasts for virtually everything that deals with void * - but there are some things in C99 that are incompatible with (at least the most widely implemented pre-C++11 variants of) C++, such as variable-length C arrays. > if (management) > { > gc = gc_new (); > struct buffer out = alloc_buf_gc (256, &gc); > > ... this is not allowed in visual studio (having a variable declaration > after "non-declaration" code), but gcc doesn't complain, so we usually > don't notice. You can make gcc complain, -pedantic -std=c89 should do it, or if you are not enabling additional compiler warnings, -pedantic-errors. And it possibly causes tons of other warnings because it nukes system extensions from the compilation environment. What I personally usually do is to test with various different compilers and configurations: 1. do not configure the source directory (or call "make distclean") 2. mkdir _build _build-c89 _build-clang _build-icc 3. for each $DIR of these new directories, do: 3a. cd $DIR 3b. ../configure CC="gcc" (or CC="gcc -std=c89 -pedantic" or "clang" or "icc" or... you name it) - you can also add CFLAGS, LDFLAGS, CPPFLAGS as you see fit, stuff -m32 to compile 32-bit code on 64-bit systems that support it (some Linux distributions would work - if they offer you i686 packages to install on your x86_64, they are usually ready; such as: Debian if you stay away from aptitude, and Fedora, for instance). 3c. make -sj4 check (use higher numbers for machines with more than 4 CPU cores) where - icc is Intel's compiler package that keeps changing names more often than I chase new versions - clang is Apple's LLVM-based free-and-open-source compiler which gives decent and useful hints, but defaults to C99 mode Best regards, Matthias
