use gcc -### in ld tests

[Alan Modra <amodra at bigpond dot net dot au>]

Some of the ld elfweak tests fail for powerpc because ld is linking
in the wrong crt* files for use in a shared lib.  This is an attempt
to fix the problem by using gcc -###.  Would one of the testsuite
gurus like to review it for me, please?

	* lib/ld-lib.exp (default_ld_link): Use "gcc -###" to choose
	correct crt* and libs.

Index: ld/testsuite/lib/ld-lib.exp
===================================================================
RCS file: /cvs/src/src/ld/testsuite/lib/ld-lib.exp,v
retrieving revision 1.20
diff -u -p -r1.20 ld-lib.exp
--- ld/testsuite/lib/ld-lib.exp	25 Apr 2003 14:23:31 -0000	1.20
+++ ld/testsuite/lib/ld-lib.exp	6 May 2003 10:09:13 -0000
@@ -115,6 +115,8 @@ proc big_or_little_endian {} {
 #	link a program using ld
 #
 proc default_ld_link { ld target objects } {
+    global CC
+    global CFLAGS
     global HOSTING_EMU
     global HOSTING_CRT0
     global HOSTING_LIBS
@@ -122,9 +124,6 @@ proc default_ld_link { ld target objects
     global host_triplet
     global link_output
 
-    set objs "$HOSTING_CRT0 $objects"
-    set libs "$LIBS $HOSTING_LIBS"
-
     if { [which $ld] == 0 } then {
 	perror "$ld does not exist"
 	return 0
@@ -135,9 +134,41 @@ proc default_ld_link { ld target objects
     } else {
 	set flags ""
     }
-    verbose -log "$ld $HOSTING_EMU $flags -o $target $objs $libs"
 
-    catch "exec $ld $HOSTING_EMU $flags -o $target $objs $libs" link_output
+    # Try to use gcc -### to set up the correct crt* and libs
+    set cc "$CC $CFLAGS"
+    if {[string match "*gcc*" $cc]} then {
+	catch "exec $cc -\#\#\#" args
+	if { [string match "*illegal option*" $args] \
+	     || [string match "*option ignored*" $args] \
+	     || [string match "*unrecognized option*" $args] } then {
+	    set args ""
+	} else {
+	    catch "exec $cc -\#\#\# $flags -o $target $objects" args
+	    # gcc -### is like gcc -v, but doesn't execute the commands
+	    # and wraps individual options in quotes.  Skip over config
+	    # and version info until we get to the ld/collect2 command.
+	    set qq [string first "\n \"" $args]
+	    if { $qq != -1 } then {
+		incr qq 3
+		# Skip the command.
+		set qq [string first "\"" $args $qq]
+		incr qq 2
+		# Use the rest of the line as our ld args.
+		set ee [string first "\n" $args $qq]
+		set args [string range $args $qq $ee]
+	    } else {
+		set args ""
+	    }
+	}
+    }
+    # Otherwise default to something that might work sometimes
+    if {[string equal $args ""]} then {
+	set args "$flags -o $target $HOSTING_CRT0 $objects $LIBS $HOSTING_LIBS"
+    }
+
+    verbose -log "$ld $HOSTING_EMU $args"
+    catch "exec $ld $HOSTING_EMU $args" link_output
     set exec_output [prune_warnings $link_output]
     if [string match "" $link_output] then {
 	return 1

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre