[llvm-dev] Why can't clang -emit-llvm when linking?

Lorenzo Laneve via llvm-dev llvm-dev at lists.llvm.org
Mon May 30 09:34:39 PDT 2016


I know right, but if I do -emit-llvm clang will emit an IR module as .ll file for each source I give him. So why can't it just emit the modules for the sources and then continue the compilation? I don't get the point of this error. Just for curiosity 

> On May 30, 2016, at 6:17 PM, David Blaikie <dblaikie at gmail.com> wrote:
> 
> There is no single LLVM IR for the entire compilation process in such a command line - separate IR is created for each source file, an object file is created, then those (native, non-IR) object files are linked together. So it's somewhat a invalid concept.
> 
> In your case, since there's only one file anyway, just add -c and you should be fine (your IR won't include the standard library/other thingsn that would be linked into the program - but those would be native objects and not IR in any case)
> 
> - Dave
> 
>> On Mon, May 30, 2016 at 5:33 AM, Lorenzo Laneve via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>> When I try to do 
>> 
>> clang++ main.cpp -emit-llvm
>> 
>> without -S, clang says that he can’t:
>> 
>> clang: error: -emit-llvm cannot be used when linking
>> 
>> 
>> why can’t it emit the IR in a complete compilation process?
>> 
>> Is there a particular technical reason or just to avoid confusing jobs?
>> 
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160530/9f2568df/attachment.html>


More information about the llvm-dev mailing list