Touching the PATH

[Akim Demaille]

Err, it seems that my message are not delivered :(  Sorry if there
_are_ duplicates.  I sent the following messages recently:

--------------------------------------------------
From: Akim Demaille <address@hidden>
Subject: Touching the PATH
To: Libtool List <address@hidden>
X-Sent: 1 day, 19 hours, 56 seconds ago


If you look at the current tarball of GNU M4, located here:

        http://www.lrde.epita.fr/~akim/download/m4-1.4q.tar.gz  or .bz2

you'll see that make distcheck fails, while make check passes.
distcheck fails in a simple way, corresponding to this:

~/src/m4/m4-1.4q/=build/tests % echo 'esyscmd(m4 --version)' | PATH=`pwd`:$PATH 
m4

m4: error while loading shared libraries: m4.so.0: cannot open shared object 
file: No such file or directory

What's wrong?

What is wrong is that the PATH is not the one I passed:

~/src/m4/m4-1.4q/=build/tests % echo 'esyscmd(echo $PATH)' | PATH=`pwd`:$PATH 
m4                                                   
/home/akim/src/m4/m4-1.4q/=build/src/.libs:/home/akim/src/m4/m4-1.4q/=build/tests:/home/akim/bin:/home/akim/bin:/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games

and therefore, it is not the m4 I wanted to run that is run:

~/src/m4/m4-1.4q/=build/tests % echo 'esyscmd(which m4)' | PATH=`pwd`:$PATH m4
/home/akim/src/m4/m4-1.4q/=build/src/.libs/m4          

Which apparently, didn't get the variables it wanted.

This is because of the following lines in ltmain,.sh:

          $echo >> $output "\
      # Export the path to the program.
      PATH=\"\$progdir:\$PATH\"
      export PATH

      exec \$program \${1+\"address@hidden"}


Why not running directly the program?  Well, because:

1997-01-28  Gordon Matzigkeit  <address@hidden>

        * ltmain.sh.in (link): Export the PATH variable in order to find
        the program, rather than giving a full path.  This helps give the
        program a less confusing value for argv[0].


but this is no longer relevant!!!  Just look at the poor name reported
by the program:

remo% ./m4 --help | sed 1q
Usage: lt-m4 [OPTION]... [FILE]...

the name is already broken by the fact that lt- is prepended.

So, because playing with PATH (and with any user var actually) is a
bad idea, I vote for the replacement of the code above by:

          $echo >> $output "\
      exec \$progdir/\$program \${1+\"address@hidden"}

Comments?

--------------------------------------------------

From: Akim Demaille <address@hidden>
Subject: Changing PATH in the wrappers
To: Libtool Patches <address@hidden>
X-Sent: 23 hours, 2 minutes, 25 seconds ago


I sent a couple of days ago a bug report.  Here is the patch I'm
suggesting.  I'm also asking for writing permission on Libtool CVS, so
that I can apply my patches.  Of course, I will wait for approvals.  I
also plan to improve Autoconf 2.55 compatibility.

Please, install this patch, as without it GNU M4 fails to distcheck.

(I have failures, but they are Fortran related.  I'll have a look at it).

Index: ChangeLog
from  Akim Demaille  <address@hidden>

        * ltmain.in: Do not change the PATH in the wrappers: let them
        launch the real binary using its path.

Index: ltmain.in
===================================================================
RCS file: /cvs/libtool/ltmain.in,v
retrieving revision 1.310
diff -u -u -r1.310 ltmain.in
--- ltmain.in 3 Nov 2002 17:35:36 -0000 1.310
+++ ltmain.in 6 Nov 2002 09:56:03 -0000
@@ -119,7 +119,7 @@
 # This seems to be the best place for them

 # Need a lot of goo to handle *both* DLLs and import libs
-# Has to be a shell function in order to 'eat' the argument
+# Has to be a shell function in order to 'eat' the argument
 # that is supplied when $file_magic_command is called.
 win32_libid () {
   win32_libid_type="unknown"
@@ -4313,14 +4313,6 @@
       # Run the actual program with our arguments.
 "
        case $host in
-       # win32 systems need to use the prog path for dll
-       # lookup to work
-       *-*-cygwin* | *-*-pw32*)
-         $echo >> $output "\
-      exec \$progdir/\$program \${1+\"address@hidden"}
-"
-         ;;
-
        # Backslashes separate directories on plain windows
        *-*-mingw | *-*-os2*)
          $echo >> $output "\
@@ -4330,11 +4322,7 @@

        *)
          $echo >> $output "\
-      # Export the path to the program.
-      PATH=\"\$progdir:\$PATH\"
-      export PATH
-
-      exec \$program \${1+\"address@hidden"}
+      exec \$progdir/\$program \${1+\"address@hidden"}
 "
          ;;
        esac
@@ -4823,7 +4811,7 @@
          if $run eval "$relink_command"; then :
          else
            $echo "$modename: error: relink \`$file' with the above command 
before installing it" 1>&2
-           exit 1
+           exit 1
          fi
        fi


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