PR ld/6430

* testsuite/ld-elfcomm/elfcomm.exp (test_sort_common): Test the
            ascending/descending argument to the --sort-common command line
            option.
            * testsuite/ld-elfcomm/sort-common.s: New file.
            * ld.h (enum sort_order): New.
            * ldlang.c (lang_check: Fix comment.
            (lang_common): Sort commons in ascending or descending order.
            (lang_one_common): Likewise.
            * lexsup.c (ld_options): Have --sort-common take an option
            argument.
            (parse_args): Handle argument to --sort-common.
            * ld.texinfo (--sort-common): Document new optional argument.
            * NEWS: Mention new feature.

ld/ChangeLog

@@ -1,3 +1,16 @@
+2008-05-31  Evandro Menezes  <evandro@yahoo.com>
+
+	PR ld/6430
+	* ld.h (enum sort_order): New.
+	* ldlang.c (lang_check: Fix comment.
+	(lang_common): Sort commons in ascending or descending order.
+	(lang_one_common): Likewise.
+	* lexsup.c (ld_options): Have --sort-common take an option
+	argument.
+	(parse_args): Handle argument to --sort-common.
+	* ld.texinfo (--sort-common): Document new optional argument.
+	* NEWS: Mention new feature.
+
 2008-05-28  Christophe Lyon  <christophe.lyon@st.com>
 	
 	* ld.texinfo: State that farcalls stubs are supported for ARM-EABI

ld/NEWS

@@ -1,8 +1,11 @@
 -*- text -*-
+* The --sort-common switch now has an optional argument which specifies the
+  direction of sorting.
+
 * The M68K linker now supports multiple GOT generation schemes controlled via
   the --got=<type> command line option.
 
-* The ARM ELF linker will now generate stubs for function calls to symbols that
+* The ARM EABI linker will now generate stubs for function calls to symbols that
   are too far away.  The placement of the stubs is controlled by a new linker
   command line option: --stub-group-size=N.
 

ld/ld.h

@@ -99,6 +99,8 @@ typedef struct name_list {
 }
 name_list;
 
+typedef enum {sort_none, sort_ascending, sort_descending} sort_order;
+  
 /* A wildcard specification.  */
 
 typedef enum {
@@ -265,7 +267,7 @@ typedef struct {
   /* If TRUE, warning messages are fatal */
   bfd_boolean fatal_warnings;
 
-  bfd_boolean sort_common;
+  sort_order sort_common;
 
   bfd_boolean text_read_only;
 

ld/ld.texinfo

@@ -1622,13 +1622,14 @@ and SunOS platforms.  On SunOS, the linker will automatically create a
 shared library if the @option{-e} option is not used and there are
 undefined symbols in the link.
 
-@item --sort-common
+@item --sort-common [= ascending | descending]
 @kindex --sort-common
-This option tells @command{ld} to sort the common symbols by alignment when
-it places them in the appropriate output sections.  First come all the
-sixteen-byte aligned symbols, then all the eight-byte, then all the
-four-byte, then all the two-byte, and then everything else.  This is to
-prevent gaps between symbols due to alignment constraints.
+This option tells @command{ld} to sort the common symbols by alignment in
+ascending or descending order when it places them in the appropriate output
+sections.  The symbol alignments considered are sixteen-byte or larger,
+eight-byte, four-byte, two-byte, and one-byte. This is to prevent gaps
+between symbols due to alignment constraints.  If no sorting order is
+specified, then descending order is assumed.
 
 @kindex --sort-section name
 @item --sort-section name

ld/ldlang.c

@@ -20,6 +20,8 @@
    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
    MA 02110-1301, USA.  */
 
+#include <limits.h>
+
 #include "sysdep.h"
 #include "bfd.h"
 #include "libiberty.h"
@@ -2699,6 +2701,13 @@ closest_target_match (const bfd_target *target, void *data)
   if (target->flavour != original->flavour)
     return 0;
 
+  /* Ignore generic big and little endian elf vectors.  */
+  if (   strcmp (target->name, "elf32-big") == 0
+      || strcmp (target->name, "elf64-big") == 0
+      || strcmp (target->name, "elf32-little") == 0
+      || strcmp (target->name, "elf64-little") == 0)
+    return 0;
+
   /* If we have not found a potential winner yet, then record this one.  */
   if (winner == NULL)
     {
@@ -5419,7 +5428,7 @@ lang_check (void)
 
 /* Look through all the global common symbols and attach them to the
    correct section.  The -sort-common command line switch may be used
-   to roughly sort the entries by size.  */
+   to roughly sort the entries by alignment.  */
 
 static void
 lang_common (void)
@@ -5434,10 +5443,24 @@ lang_common (void)
     bfd_link_hash_traverse (link_info.hash, lang_one_common, NULL);
   else
     {
-      int power;
+      unsigned int power;
 
-      for (power = 4; power >= 0; power--)
-	bfd_link_hash_traverse (link_info.hash, lang_one_common, &power);
+      if (config.sort_common == sort_descending)
+        {
+          for (power = 4; power > 0; power--)
+  	    bfd_link_hash_traverse (link_info.hash, lang_one_common, &power);
+  	    
+  	  power = 0;
+          bfd_link_hash_traverse (link_info.hash, lang_one_common, &power);
+        }
+      else
+        {
+          for (power = 0; power <= 4; power++)
+            bfd_link_hash_traverse (link_info.hash, lang_one_common, &power);
+
+      	  power = UINT_MAX;
+	  bfd_link_hash_traverse (link_info.hash, lang_one_common, &power);
+	}
     }
 }
 
@@ -5456,8 +5479,11 @@ lang_one_common (struct bfd_link_hash_entry *h, void *info)
   size = h->u.c.size;
   power_of_two = h->u.c.p->alignment_power;
 
-  if (config.sort_common
-      && power_of_two < (unsigned int) *(int *) info)
+  if (config.sort_common == sort_descending
+      && power_of_two < *(unsigned int *) info)
+    return TRUE;
+  else if (config.sort_common == sort_ascending
+           && power_of_two > *(unsigned int *) info)
     return TRUE;
 
   section = h->u.c.p->section;

ld/lexsup.c

@@ -473,8 +473,10 @@ static const struct ld_option ld_options[] =
     '\0', NULL, N_("Create a position independent executable"), ONE_DASH },
   { {"pic-executable", no_argument, NULL, OPTION_PIE},
     '\0', NULL, NULL, TWO_DASHES },
-  { {"sort-common", no_argument, NULL, OPTION_SORT_COMMON},
-    '\0', NULL, N_("Sort common symbols by size"), TWO_DASHES },
+  { {"sort-common", optional_argument, NULL, OPTION_SORT_COMMON},
+    '\0', N_("[=ascending|descending]"), 
+    N_("Sort common symbols by alignment [in specified order]"), 
+    TWO_DASHES },
   { {"sort_common", no_argument, NULL, OPTION_SORT_COMMON},
     '\0', NULL, NULL, NO_HELP },
   { {"sort-section", required_argument, NULL, OPTION_SORT_SECTION},
@@ -1142,7 +1144,14 @@ parse_args (unsigned argc, char **argv)
 	  command_line.soname = optarg;
 	  break;
 	case OPTION_SORT_COMMON:
-	  config.sort_common = TRUE;
+	  if (optarg == NULL
+	      || strcmp (optarg, N_("descending")) == 0)
+            config.sort_common = sort_descending;
+          else if (strcmp (optarg, N_("ascending")) == 0)
+	    config.sort_common = sort_ascending;
+	  else
+	    einfo (_("%P%F: invalid common section sorting option: %s\n"),
+		   optarg);
 	  break;
 	case OPTION_SORT_SECTION:
 	  if (strcmp (optarg, N_("name")) == 0)

ld/testsuite/ChangeLog

@@ -1,3 +1,11 @@
+2008-05-31  Nick Clifton  <nickc@redhat.com>
+
+	PR ld/6430
+	* ld-elfcomm/elfcomm.exp (test_sort_common): Test the
+	ascending/descending argument to the --sort-common command line
+	option.
+	* ld-elfcomm/sort-common.s: New file.
+
 2008-05-28  Christophe Lyon  <christophe.lyon@st.com>
 	
 	* ld-arm/arm-elf.exp: Skip farcalls tests for non-ARM-EABI

ld/testsuite/ld-elfcomm/elfcomm.exp

@@ -28,6 +28,74 @@ if ![is_elf_format] {
     return
 }
 
+proc test_sort_common {} {
+    global exec_output
+    global objdump
+    global srcdir
+    global subdir
+    global as
+    global ld
+  
+    set test "--sort-common (descending)"
+  
+    verbose "Check to see that --sort-common sorts in descending alignment"
+
+    # We do not run the sort common tests for the DLX target because we know that the linker
+    # will seg-fault.  The built-in DLX linker script requires that there be something in the
+    # .text section and our sort-common.s file does not provide anything.
+    if [istarget dlx-*-*] {
+	untested "$test"
+	return 0
+    }
+    
+    if { ![ld_assemble $as $srcdir/$subdir/sort-common.s tmpdir/sort-common.o] } {
+	unresolved "$test"
+	return 0
+    }
+
+    if { ![ld_simple_link $ld tmpdir/sort-common.dx "--sort-common=descending tmpdir/sort-common.o"] } {
+	fail "$test"
+	return 0
+    }
+
+    send_log "$objdump --syms tmpdir/sort-common.dx | grep var | sort\n"
+    set exec_output [run_host_cmd "$objdump" "--syms tmpdir/sort-common.dx | grep var | sort"]
+
+    # Don't know why, but the CR ports fail this test.
+    setup_xfail "cr16-*-*" "crx-*-*"
+
+    # Note: The second regexp is for targets which put small commons in a .sbss
+    #  section and large commons in a .bss section.
+    if {   ![regexp ".*var_16.*var_8.*var_4.*var_2.*var_1.*" $exec_output]
+        && ![regexp ".*sbss.*var_8.*var_4.*var_2.*var_1.*bss.*var_16.*" $exec_output] } {      
+	fail $test
+    } else {
+	pass $test
+    }
+
+    set test "--sort-common (ascending)"
+  
+    verbose "Check to see that --sort-common=ascending sorts in ascending alignment"
+
+    if { ![ld_simple_link $ld tmpdir/sort-common.ax "--sort-common=ascending tmpdir/sort-common.o"] } {
+	fail "$test"
+	return 0
+    }
+
+    send_log "$objdump --syms tmpdir/sort-common.ax | grep var | sort\n"
+    set exec_output [run_host_cmd "$objdump" "--syms tmpdir/sort-common.ax | grep var | sort"]
+
+    if {![regexp ".*var_1.*var_2.*var_4.*var_8.*var_16.*" $exec_output]} {      
+	fail $test
+	return 0
+    }
+
+    pass $test
+    return 1
+}
+
+test_sort_common
+
 set test1	"size/aligment change of common symbols"
 set test1w1	"$test1 (warning 1)"
 set test1w2	"$test1 (warning 2)"

ld/testsuite/ld-elfcomm/sort-common.s

@@ -0,0 +1,6 @@
+        .comm   var_1byte_align,1,1
+        .comm   var_2byte_align,2,2
+        .comm   var_4byte_align,4,4
+        .comm   var_8byte_align,8,8
+        .comm   var_16byte_align,16,16
+