Re: multilib patch

[Ralf Wildenhues]

Hi Peter,

* Peter O'Gorman wrote on Wed, Jan 30, 2008 at 09:16:38AM CET:
> Not much response last time, here we go again.

Sorry about the delay.

> Ok to apply to branch-1-5 and forward port to HEAD?

Nits below.

FWIW, on Debian x86_64, this patch causes for me /usr/lib to appear
in the front, with both 64bit mode (./configure) and 32bit mode
(./configure CPPFLAGS=-m32 LDFLAGS=-m32).  For Debian, the latter
is wrong, /usr/lib64 is a symlink to /usr/lib.  Before the patch,
both modes looked better.

A general question: do all these changes to multilib path searching
not also increase the set of paths we search?  Because that will
rather significantly affect libtool performance in some cases.

> +# Need LDFLAGS, but not with -L.
> +_lt_ldflags=
> +for _ld_flag in "$LDFLAGS"; do
> +  case "$_ld_flag" in
> +    -L*) ;;
> +    *) _lt_ldflags="$_ld_flag $_lt_ldflags" ;;
> +  esac
> +done 
> +echo 'int main() { return 1;}' > conftest.c
> +_lt_verbose_search_libs=`$CC $CFLAGS $CPPFLAGS $_lt_ldflags -o conftest -v 
> conftest.c 2>&1 | awk '

Please list CPPFLAGS before CFLAGS.

> +BEGIN {lt_space=0;} /-L/ {
> +  for (lt_x=1; lt_x <= NF; lt_x++) {
> +    if ( substr($lt_x,1,2) == "-L") {
> +      lt_y=substr($lt_x,3,length($lt_x) -2);
> +      if (lt_space > 0) { print " "; }
> +      print lt_y;
> +      lt_space++;
> +    }
> +  }
> +}' | awk '
> +BEGIN {RS=" "; FS="/|\n";} {

For Solaris awk, FS must contain one character only.
You could AC_REQUIRE([AC_PROG_AWK]) and use $AWK.

Hmm, I see that this idiom was used before this patch already.
Still, it will not do TRT on Solaris.

Wait... this whole awk processing of paths used to be GNU/Linux
only, now it is for all systems, but $GCC only.

> +  lt_foo="";
> +  lt_count=0;
> +  for (lt_i = NF; lt_i > 0; lt_i--) {
> +    if ($lt_i != "" && $lt_i != ".") {
> +      if ($lt_i == "..") {
> +        lt_count++;
> +      } else {
> +        if (lt_count == 0) {
> +          lt_foo="/" $lt_i lt_foo;
> +        } else {
> +          lt_count--;
> +        }
> +      }
> +    }
> +  }
> +  if (lt_foo != "") { lt_freq[[lt_foo]]++; }
> +  if (lt_freq[[lt_foo]] == 1) { print lt_foo; }
> +}'`
> +rm -rf conftest*
> +for _lt_verbose_search_lib in $_lt_verbose_search_libs; do
> +  case " $sys_lib_search_path_spec " in
> +   *" "$_lt_verbose_search_lib" "*) ;;
> +   *) sys_lib_search_path_spec="$_lt_verbose_search_lib 
> $sys_lib_search_path_spec" ;;
> +  esac
> +done
> +])