Relative DT_RPATH/DT_RUNPATH vs. sysroot capable ld.

[Alan Modra <amodra at gmail dot com>]

This fixes two problems.  First, the --sysroot option wasn't available
with a ld configured without --with-sysroot, a historical accident.
This led to people configuring binutils with --with-sysroot=/ in order
to enable sysroot support, which exposes a case where ld wrongly
prepends the sysroot to a relative path.

	PR ld/18992
	* ldmain.c (main): Always enable --sysroot.
	* emultempl/elf32.em (gld${EMULATION_NAME}_after_open): Don't
	prepend sysroot to relative rpath/runpath.

diff --git a/ld/emultempl/elf32.em b/ld/emultempl/elf32.em
index ea6d48c..8ff5fe0 100644
--- a/ld/emultempl/elf32.em
+++ b/ld/emultempl/elf32.em
@@ -1256,12 +1256,16 @@ fragment <<EOF
 	  rp = bfd_elf_get_runpath_list (link_info.output_bfd, &link_info);
 	  for (; !found && rp != NULL; rp = rp->next)
 	    {
-	      char *tmpname = gld${EMULATION_NAME}_add_sysroot (rp->name);
+	      const char *tmpname = rp->name;
+
+	      if (IS_ABSOLUTE_PATH (tmpname))
+		tmpname = gld${EMULATION_NAME}_add_sysroot (tmpname);
 	      found = (rp->by == l->by
 		       && gld${EMULATION_NAME}_search_needed (tmpname,
 							      &n,
 							      force));
-	      free (tmpname);
+	      if (tmpname != rp->name)
+		free ((char *) tmpname);
 	    }
 	  if (found)
 	    break;
diff --git a/ld/ldmain.c b/ld/ldmain.c
index 577928d..96d7fe8 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -222,15 +222,7 @@ main (int argc, char **argv)
   /* Set up the sysroot directory.  */
   ld_sysroot = get_sysroot (argc, argv);
   if (*ld_sysroot)
-    {
-      if (*TARGET_SYSTEM_ROOT == 0)
-	{
-	  einfo ("%P%F: this linker was not configured to use sysroots\n");
-	  ld_sysroot = "";
-	}
-      else
-	ld_canon_sysroot = lrealpath (ld_sysroot);
-    }
+    ld_canon_sysroot = lrealpath (ld_sysroot);
   if (ld_canon_sysroot)
     ld_canon_sysroot_len = strlen (ld_canon_sysroot);
   else

-- 
Alan Modra
Australia Development Lab, IBM