Re: [cfe-users] How to change alignment of long long
Found another one that encountered this problem: http://lists.llvm.org/pipermail/cfe-dev/2013-October/032554.html Again no solution there. Is anyone sucessfully using clang (preferably 3.8) with an alignment for long long or double that is not 64 bits? Philipp ___ cfe-users mailing list cfe-users@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users
[cfe-users] Use of undeclared identifier error
Hi, I've got a program using libclang to compile C/C++ scripts at run-time. When trying to use it with libstdc++, specifically , although I get similar errors when using other standard headers, I get errors of the form "use of undeclared identifier '__builtin_clz'; did you mean '__builtin_clz'?" or "unknown type name '__builtin_va_list'; did you mean '__builtin_va_list'?" I've checked the list of identifiers to see that __builtin_clz (and others that it's complaining about) are in there, and __builtin_va_list is defined in the ASTContext. The full code for how I've set up and am calling the compilation are at http://pastebin.com/SASu4xMi and the output from clang::ParseAST when including is at http://pastebin.com/UphYaNj8 . Despite the outside saying that those builtins exist, using the program at http://pastebin.com/UphYaNj8 says that the builtins don't exist at compilation time. Cheers, Rohan Smith ___ cfe-users mailing list cfe-users@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users
Re: [cfe-users] How to change alignment of long long
On 22.10.2016 09:35, Philipp Klaus Krause via cfe-users wrote: > Found another one that encountered this problem: > > http://lists.llvm.org/pipermail/cfe-dev/2013-October/032554.html > > Again no solution there. > > Is anyone sucessfully using clang (preferably 3.8) with an alignment for > long long or double that is not 64 bits? > > Philipp To all the other encountering this issue: I was able to track down the issue. In general, alignment handling in clang is a mess. Yes, there are some values in the Target for alignment, but they dont't always do what one might think. They seem to be fine for char, int, long and float. For short, there is none, as short alignment is hardcoded to 16 bits. For long long and double there are alignment values, but they are not used. Instead the width is used as alignment: In ASTContext::getPreferredTypeAlign, unless the target is xcore, for double, long long and unsigned long long, the alignment of the type is replaced by the width. So, to make alignment for long long and double work, you need add a special case for your target in ASTContext::getPreferredTypeAlign like there already is for xcore. And to make alignment work for short, you need to make getShortAlign() virtual in TargetInfo and override it in your Target. Philipp P.S.: I am using clang 3.8, the above might or might not apply to other versions. signature.asc Description: OpenPGP digital signature ___ cfe-users mailing list cfe-users@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users
