December 2010 Archives

llvm

llvm-ld  -link-as-library -native -O5 re_exec.o re_comp.o re.o  -o ../../lib/auto/re/re.so

=> Still a bytecode file. Why?

This is my idea:

diff --git a/Makefile.SH b/Makefile.SH
index 0a2df3e..c418686 100755
--- a/Makefile.SH
+++ b/Makefile.SH
@@ -178,6 +178,21 @@ EOT
        ;;
 esac

+: TODO replace $(CC) -o with $(LD) -o
+case "$cc" in
+llvm-gcc*)
+        ld=llvm-ld
+        ar=llvm-ar
+        ldflags=-native `echo "$ldflags" | sed 's/-fstack-protector//'`
+        lddlflags=-link-as-library -native -disable-internalize `echo "$lddlflags" | sed 's/-fstack-protector//'`
+        slddlflags=$lddlflags
+        cddlflags=
+        ccflags="-emit-llvm $ccflags"
+        archname="$archname-llvm"
+        ;;
+esac
+
+
 : Prepare dependency lists for Makefile.
 dynamic_list=' '
 dynamic_ext_re="lib/auto/re/re.$dlext"

Looks like llvm-ld contrary to the man page alway emits bytecode, which has to be assembled by something like this to a ELF/COFF .so/.dll:

$ld $lddlflags; llc a.out -o - | as -o $@

llvm-ld  -link-as-library -native -O5 re_exec.o re_comp.o re.o -o a.out && \
  llc a.out -o - | as -o ../../lib/auto/re/re.so

I could not get llvm-ld to write to pipes:

$ llvm-ld -native -link-as-library -O5 re_exec.bc re_comp.bc re.bc -o -| llc - -o - | \
   as -o  ../../lib/auto/re/re.so
llc: bitcode didn't read correctly.
Reason: Invalid bitcode signature

We might also be forced to save to .s and compile with cc -shared

On the CC vs LD problem

Still thinking about the CC => LD patchup for llvm. Other non-gcc/cl compilers would also like to use LD to link executables from objects files I guess. Legacy.

About Reini Urban

user-pic Working at cPanel on B::C (the perl-compiler), p2, types, parrot, B::Generate, cygwin perl and more guts (LLVM, jit, optimizations).