Hi,
I'm just trying to get started with a simple example with LLVM under
windows. I downloaded the mingw binaries from the website and would
like to compile a program. (PS: The mingw binaries did not come with
any documentation on what they are and how to use them)
I used the online code generator (http://llvm.org/demo/index.cgi) to
compile hello world:
#include <stdio.h>
int main() {
printf("hello world\n");
return 0;
}
Copied it's output
; ModuleID = '/tmp/webcompile/_3997_0.bc'
target datalayout
"e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
target triple = "i386-pc-linux-gnu"
@.str = internal constant [12 x i8] c"hello world\00" ; <[12 x
i8]*> [#uses=1]
define i32 @main() nounwind {
entry:
%0 = tail call i32 @puts(i8* getelementptr ([12 x i8]* @.str, i32 0,
i32 0)) nounwind ; <i32> [#uses=0]
ret i32 0
}
declare i32 @puts(i8*)
into a bc file, and tried to run it with lli, but I get this error:
"lli: error loading program 'hello.bc': Bitcode stream should be a
multiple of 4
bytes in length"
(I'm guessing I also need to change the 'target' type to something
non-linux...?)
How can I get LLVM to compile, assemble, link and generate a simple exe?
Thanks.
Hi,> Copied it's output > ; ModuleID = '/tmp/webcompile/_3997_0.bc' > target datalayout > "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32" > target triple = "i386-pc-linux-gnu" > @.str = internal constant [12 x i8] c"hello world\00" ; <[12 x i8]*> [#uses=1] > > define i32 @main() nounwind { > entry: > %0 = tail call i32 @puts(i8* getelementptr ([12 x i8]* @.str, i32 0, > i32 0)) nounwind ; <i32> [#uses=0] > ret i32 0 > } > > declare i32 @puts(i8*) > > into a bc file, and tried to run it with lli, but I get this error: > > "lli: error loading program 'hello.bc': Bitcode stream should be a multiple of 4 > bytes in length"lli and most other tools expect bitcode (.bc) and not LLVM human readable assembler (.ll). The demo page produces .ll because it's for humans to read! Copy the demo output into hello.ll, and then do: llvm-as hello.ll This will produce hello.bc, which you can run using lli. Ciao, Duncan.
PS:> How can I get LLVM to compile, assemble, link and generate a simple exe?use llvm-gcc, which works the same as gcc.
Hi Duncan, Thanks for the reply, that did indeed work. I realise that I could use llvm-gcc but I want to learn how to use the parts of llvm that would allow me to make my own compiler (eventually), also at this point I'm trying to avoid having to build all of llvm myself and just use what is available pre-built from the site. I was wondering how to actually create the exe? For example with gcc: gcc hello.c -S -o hello_gcc.s produces a native assembly file and then gcc hello_gcc.s -o hello_gcc_asm.exe will produce the final "hello world" I can run. With llvm, I've done: hello.c to hello.ll via the online LLVM compiler tool (http://llvm.org/demo/index.cgi) then llvm-as hello.ll to create the hello.bc, then llc hello.bc to create the hello.s but if I try and create an exe from this assembly file with gcc I get a number of errors, Likewise, "cl.exe" (microsoft compiler) says "cl : Command line warning D9024 : unrecognized source file type 'hello.s', object file assumed" PS: Including a link to this: "http://llvm.org/cmds/" in the mingw distribution would probably help other people get up and running quicker.