ld:

2008-01-11  Tristan Gingold  <gingold@adacore.com>
	    Eric Botcazou  <ebotcazou@adacore.com>

	* ldlang.c (lang_end): Warns if the entry point is not found when
	--gc-sections.
	Emit an error if no root is specified when --gc-sections -r.
	* ld.texinfo (Options): Document that --gc-sections is compatible
	with -r and -q.
	* ldmain.c (main): Do not error out if -r and --gc-sections.
	* scripttempl/elf.sc: Emit ENTRY command only if relocating.

ld/testsuite:
2008-01-11  Tristan Gingold  <gingold@adacore.com>

	* lib/ld-lib.exp (check_gc_sections_available): Now available on
	VxWorks.
	* ld-gc: New directory for testing --gc-sections.
	* ld-gc/gc.c: New file.
	* ld-gc/gc.exp: New file.
	* ld-gc/noent.s: New file.
	* ld-gc/noent.d: New file.

ld/ChangeLog

@@ -1,3 +1,14 @@
+2008-01-11  Tristan Gingold  <gingold@adacore.com>
+	    Eric Botcazou  <ebotcazou@adacore.com>
+
+	* ldlang.c (lang_end): Warns if the entry point is not found when
+	--gc-sections.
+	Emit an error if no root is specified when --gc-sections -r.
+	* ld.texinfo (Options): Document that --gc-sections is compatible
+	with -r and -q.
+	* ldmain.c (main): Do not error out if -r and --gc-sections.
+	* scripttempl/elf.sc: Emit ENTRY command only if relocating.
+
 2008-01-10  Daniel Jacobowitz  <drow@sources.redhat.com>
 
 	PR ld/5533

ld/genscrba.sh

@@ -8,7 +8,9 @@ source_em()
 }
 fragment()
 {
-  local lineno=$[${BASH_LINENO[0]} + 1]
+  if [ ${BASH_VERSINFO[3]} -ge 3 ]; then
-  echo >> e${EMULATION_NAME}.c "#line $lineno \"$em_script\""
+    local lineno=$[${BASH_LINENO[0]} + 1]
+    echo >> e${EMULATION_NAME}.c "#line $lineno \"$em_script\""
+  fi
   cat >> e${EMULATION_NAME}.c
 }

ld/ld.texinfo

@@ -1280,8 +1280,7 @@ it ends in a @code{.exe} suffix.
 @item --gc-sections
 @itemx --no-gc-sections
 Enable garbage collection of unused input sections.  It is ignored on
-targets that do not support this option.  This option is not compatible
+targets that do not support this option.  The default behaviour (of not
-with @samp{-r} or @samp{--emit-relocs}. The default behaviour (of not
 performing this garbage collection) can be restored by specifying
 @samp{--no-gc-sections} on the command line.
 
@@ -1295,6 +1294,11 @@ referenced.  Once this initial set of sections has been determined,
 the linker recursively marks as used any section referenced by their
 relocations.  See @samp{--entry} and @samp{--undefined}.
 
+This option can be set when doing a partial link (enabled with option
+@samp{-r}).  In this case the root of symbols kept must be explicitely 
+specified either by an @samp{--entry} or @samp{--undefined} option or by
+a @code{ENTRY} command in the linker script.
+
 @kindex --print-gc-sections
 @kindex --no-print-gc-sections
 @cindex garbage collection

ld/ldlang.c

@@ -5077,11 +5077,20 @@ lang_end (void)
   struct bfd_link_hash_entry *h;
   bfd_boolean warn;
 
-  if (link_info.relocatable || link_info.shared)
+  if ((link_info.relocatable && !link_info.gc_sections)
+      || link_info.shared)
     warn = entry_from_cmdline;
   else
     warn = TRUE;
 
+  /* Force the user to specify a root when generating a relocatable with
+     --gc-sections.  */
+  if (link_info.gc_sections && link_info.relocatable
+      && (entry_symbol.name == NULL
+	  && ldlang_undef_chain_list_head == NULL))
+    einfo (_("%P%F: gc-sections requires either an entry or "
+	     "an undefined symbol\n"));
+
   if (entry_symbol.name == NULL)
     {
       /* No entry has been specified.  Look for the default entry, but

ld/ldmain.c

@@ -292,9 +292,7 @@ main (int argc, char **argv)
 
   if (link_info.relocatable)
     {
-      if (link_info.gc_sections)
+      if (command_line.relax)
-	einfo ("%P%F: --gc-sections and -r may not be used together\n");
-      else if (command_line.relax)
 	einfo (_("%P%F: --relax and -r may not be used together\n"));
       if (link_info.shared)
 	einfo (_("%P%F: -r and -shared may not be used together\n"));

ld/scripttempl/elf.sc

@@ -250,7 +250,7 @@ cat <<EOF
 OUTPUT_FORMAT("${OUTPUT_FORMAT}", "${BIG_OUTPUT_FORMAT}",
 	      "${LITTLE_OUTPUT_FORMAT}")
 OUTPUT_ARCH(${OUTPUT_ARCH})
-ENTRY(${ENTRY})
+${RELOCATING+ENTRY(${ENTRY})}
 
 ${RELOCATING+${LIB_SEARCH_DIRS}}
 ${RELOCATING+${EXECUTABLE_SYMBOLS}}

ld/testsuite/ChangeLog

@@ -1,3 +1,13 @@
+2008-01-10  Tristan Gingold  <gingold@adacore.com>
+
+	* lib/ld-lib.exp (check_gc_sections_available): Now available on
+	VxWorks.
+	* ld-gc: New directory for testing --gc-sections.
+	* ld-gc/gc.c: New file.
+	* ld-gc/gc.exp: New file.
+	* ld-gc/noent.s: New file.
+	* ld-gc/noent.d: New file.
+
 2008-01-09  Richard Sandiford  <rsandifo@nildram.co.uk>
 
 	PR ld/5526

ld/testsuite/ld-gc/gc.c

@@ -0,0 +1,20 @@
+int unused_var = 7;
+int used_var = 7;
+
+int
+unused_func (int v)
+{
+  return 3 * unused_var;
+}
+
+int
+used_func (int v)
+{
+  return 2 * used_var;
+}
+
+int
+main (void)
+{
+  return used_func (5);
+}

ld/testsuite/ld-gc/gc.exp

@@ -0,0 +1,71 @@
+# Expect script for ld-gc tests
+#   Copyright 2008
+#   Free Software Foundation, Inc.
+#
+# This file is part of the GNU Binutils.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+# MA 02110-1301, USA.
+
+# These tests require --gc-sections
+if ![check_gc_sections_available] {
+    return
+}
+
+set cflags "-ffunction-sections -fdata-sections"
+set objfile "tmpdir/gc.o"
+
+ld_compile "$CC -c $CFLAGS $cflags" $srcdir/$subdir/gc.c $objfile
+
+proc test_gc { testname filename linker ldflags} {
+    global nm
+    global srcdir
+    global subdir
+    global nm_output
+    global objfile
+
+    set outfile "tmpdir/$filename"
+
+    if ![ld_simple_link $linker $outfile "-L$srcdir/$subdir $ldflags $objfile"] {
+	    fail $testname
+	return
+    }
+    if ![ld_nm $nm "" $outfile] {
+	unresolved $testname
+	return
+    }
+    if {![info exists nm_output(used_func)] \
+	    || ![info exists nm_output(used_var)]} {
+	send_log "used sections do not exist\n"
+	verbose "used sections do not exist"
+	fail $testname
+	return
+    }
+    if {[info exists nm_output(unused_func)] \
+	    || [info exists nm_output(unused_var)]} {
+	send_log "unused section still here\n"
+	verbose "unused section still here"
+	fail $testname
+	return
+    }
+    pass $testname
+}
+
+test_gc "Check --gc-section" "gcexe" $ld "--gc-sections -e main"
+test_gc "Check --gc-section/-q" "gcrexe" $ld "--gc-sections -q -e main"
+test_gc "Check --gc-section/-r/-e" "gcrel" $ld "-r --gc-sections -e main"
+test_gc "Check --gc-section/-r/-u" "gcrel" $ld "-r --gc-sections -u used_func"
+
+run_dump_test "noent"

ld/testsuite/ld-gc/noent.d

@@ -0,0 +1,3 @@
+# name: --gc-sections -r without -e
+# ld: --gc-sections -r
+# error: gc-sections requires either an entry or an undefined symbol

ld/testsuite/ld-gc/noent.s

@@ -0,0 +1,4 @@
+	.text
+	.globl entry
+entry:
+	.long 0

ld/testsuite/lib/ld-lib.exp

@@ -1559,14 +1559,6 @@ proc check_gc_sections_available { } {
 	    return 0
 	}
 
-	# VxWorks kernel modules are relocatable objects linked with -r,
-	# while RTP executables are linked with -q (--emit-relocs).
-	# Both of these options are incompatible with --gc-sections.
-	if { [istarget *-*-vxworks*] } {
-	    set gc_sections_available_saved 0
-	    return 0
-	}
-
 	# Check if the ld used by gcc supports --gc-sections.
 	set ld_output [remote_exec host $ld "--help"]
 	if { [ string first "--gc-sections" $ld_output ] >= 0 } {