symlink calculation in bootstrap script

[Bruno Haible]

Hi,

Here's a patch to lift a few restrictions in the bootstrap script.


2006-10-08  Bruno Haible  <address@hidden>

        * bootstrap (func_relativize): New function, taken from gnulib-tool.
        (symlink_to_gnulib): Use it.

*** bootstrap.bak       2006-10-07 15:40:13.000000000 +0200
--- bootstrap   2006-10-08 14:14:24.000000000 +0200
***************
*** 245,267 ****
    fi;;
  esac
  
  symlink_to_gnulib()
  {
    src=$GNULIB_SRCDIR/$1
    dst=${2-$1}
-   dot_dots=
- 
    case $src in
!   /*) ;;
    *)
!     case /$dst/ in
!     *//* | */../* | */./* | /*/*/*/*/*/)
!        echo >&2 "$0: invalid symlink calculation: $src -> $dst"
!        exit 1;;
!     /*/*/*/*/)        dot_dots=../../../;;
!     /*/*/*/)  dot_dots=../../;;
!     /*/*/)    dot_dots=../;;
!     esac;;
    esac
  
    test -f "$src" && {
--- 251,304 ----
    fi;;
  esac
  
+ # func_relativize DIR1 DIR2
+ # computes a relative pathname RELDIR such that DIR1/RELDIR = DIR2.
+ # Input:
+ # - DIR1            relative pathname, relative to the current directory
+ # - DIR2            relative pathname, relative to the current directory
+ # Output:
+ # - reldir          relative pathname of DIR2, relative to DIR1
+ func_relativize ()
+ {
+   dir0=`pwd`
+   dir1="$1"
+   dir2="$2"
+   sed_first='s,^\([^/]*\)/.*$,\1,'
+   sed_rest='s,^[^/]*/*,,'
+   sed_last='s,^.*/\([^/]*\)$,\1,'
+   sed_butlast='s,/*[^/]*$,,'
+   while test -n "$dir1"; do
+     first=`echo "$dir1" | sed -e "$sed_first"`
+     if test "$first" != "."; then
+       if test "$first" = ".."; then
+         dir2=`echo "$dir0" | sed -e "$sed_last"`/"$dir2"
+         dir0=`echo "$dir0" | sed -e "$sed_butlast"`
+       else
+         first2=`echo "$dir2" | sed -e "$sed_first"`
+         if test "$first2" = "$first"; then
+           dir2=`echo "$dir2" | sed -e "$sed_rest"`
+         else
+           dir2="../$dir2"
+         fi
+         dir0="$dir0"/"$first"
+       fi
+     fi
+     dir1=`echo "$dir1" | sed -e "$sed_rest"`
+   done
+   reldir="$dir2"
+ }
+ 
  symlink_to_gnulib()
  {
    src=$GNULIB_SRCDIR/$1
    dst=${2-$1}
    case $src in
!   /*) reldir=$src;;
    *)
!     case $dst in
!     /*) reldir=$src;;
!     *) func_relativize "$dst" "$src";;
!     esac
    esac
  
    test -f "$src" && {
***************
*** 269,276 ****
      src_ls=`ls -diL "$src" 2>/dev/null` && set $src_ls && src_i=$1 &&
      dst_ls=`ls -diL "$dst" 2>/dev/null` && set $dst_ls && dst_i=$1 &&
      test "$src_i" = "$dst_i" || {
!       echo "$0: ln -fs $dot_dots$src $dst" &&
!       ln -fs "$dot_dots$src" "$dst"
      }
    }
  }
--- 306,313 ----
      src_ls=`ls -diL "$src" 2>/dev/null` && set $src_ls && src_i=$1 &&
      dst_ls=`ls -diL "$dst" 2>/dev/null` && set $dst_ls && dst_i=$1 &&
      test "$src_i" = "$dst_i" || {
!       echo "$0: ln -fs $reldir $dst" &&
!       ln -fs "$reldir" "$dst"
      }
    }
  }