[LLVMdev] How can I get llvm-as for Ubuntu?

[Nick Lewycky]

Andrew Pennebaker wrote:
> I used to be able to `apt-get install llvm` to install `llvm-as`, an
> LLVM assembler. I think some tools/packages have moved around since then.
>
> What can I use to compile `.ll` assembler files into executables?

You'll have to ask your distributor about how llvm is packaged, but I 
can answer about what the tools are.

llvm-as converts .ll to .bc. The formats are equivalent except that the 
former is human readable and the latter is machine readable. They are 
both LLVM IR (llvm's assembly format) not native machine code.

llc converts .ll or .bc to .s (native assembly) or .o files (native 
object file). These are what you commonly get out of a compiler, and 
must be linked to form an executable.

llvm-mc converts between .s and .o. It is a native assembler and 
disassembler.

Given a set of .o files, you need to (native) link them to form an 
executable. LLVM proper does not include a native linker. (llvm-link is 
not one, it combines multiple .bc files into a single .bc file. You'll 
still need a native linker.) There is the lld.llvm.org project which you 
can use to link, if you want to use llvm parts.

So I think the answer you want is "llc foo.ll -filetype=obj -o foo.o" 
and then you link foo.o with "ld" on your system.

Nick