Preserve the maximum alignment/size for common symbols.

bfd/

2011-10-08  H.J. Lu  <hongjiu.lu@intel.com>

	PR ld/13250
	* elflink.c (elf_link_add_object_symbols): Preserve the maximum
	alignment and size for common symbols.

ld/testsuite/

2011-10-08  H.J. Lu  <hongjiu.lu@intel.com>

	PR ld/13250
	* ld-elf/shared.exp (build_tests): Add tests for PR ld/13250.
	(run_tests): Likewise.

	* ld-elf/pr13250-1.c: New.
	* ld-elf/pr13250-2.c: Likewise.
	* ld-elf/pr13250-3.c: Likewise.

bfd/ChangeLog

@@ -1,3 +1,9 @@
+2011-10-08  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/13250
+	* elflink.c (elf_link_add_object_symbols): Preserve the maximum
+	alignment and size for common symbols.
+
 2011-10-08  Alan Modra  <amodra@gmail.com>
 
 	PR ld/13229

bfd/elflink.c

@@ -4515,6 +4515,8 @@ error_free_dyn:
 	{
 	  struct bfd_hash_entry *p;
 	  struct elf_link_hash_entry *h;
+	  bfd_size_type size;
+	  unsigned int alignment_power;
 
 	  for (p = htab->root.table.table[i]; p != NULL; p = p->next)
 	    {
@@ -4524,6 +4526,20 @@ error_free_dyn:
 	      if (h->dynindx >= old_dynsymcount)
 		_bfd_elf_strtab_delref (htab->dynstr, h->dynstr_index);
 
+	      /* Preserve the maximum alignment and size for common
+		 symbols even if this dynamic lib isn't on DT_NEEDED
+		 since it can still be loaded at the run-time by another
+		 dynamic lib.  */
+	      if (h->root.type == bfd_link_hash_common)
+		{
+		  size = h->root.u.c.size;
+		  alignment_power = h->root.u.c.p->alignment_power;
+		}
+	      else
+		{
+		  size = 0;
+		  alignment_power = 0;
+		}
 	      memcpy (p, old_ent, htab->root.table.entsize);
 	      old_ent = (char *) old_ent + htab->root.table.entsize;
 	      h = (struct elf_link_hash_entry *) p;
@@ -4532,6 +4548,13 @@ error_free_dyn:
 		  memcpy (h->root.u.i.link, old_ent, htab->root.table.entsize);
 		  old_ent = (char *) old_ent + htab->root.table.entsize;
 		}
+	      else if (h->root.type == bfd_link_hash_common)
+		{
+		  if (size > h->root.u.c.size)
+		    h->root.u.c.size = size;
+		  if (alignment_power > h->root.u.c.p->alignment_power)
+		    h->root.u.c.p->alignment_power = alignment_power;
+		}
 	    }
 	}
 

ld/testsuite/ChangeLog

@@ -1,3 +1,13 @@
+2011-10-08  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/13250
+	* ld-elf/shared.exp (build_tests): Add tests for PR ld/13250.
+	(run_tests): Likewise.
+
+	* ld-elf/pr13250-1.c: New.
+	* ld-elf/pr13250-2.c: Likewise.
+	* ld-elf/pr13250-3.c: Likewise.
+
 2011-10-07  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* ld-elf/elf.exp: Run --gc-sections tests only if --gc-sections

ld/testsuite/ld-elf/pr13250-1.c

@@ -0,0 +1,8 @@
+int common1[8];
+void
+foo ()
+{
+  int i;
+  for (i = 0; i < sizeof (common1)/ sizeof (common1[0]); i++)
+    common1[i] = -1;
+}

ld/testsuite/ld-elf/pr13250-2.c

@@ -0,0 +1,10 @@
+extern int common1[8];
+
+extern void foo ();
+
+int
+bar ()
+{
+  foo ();
+  return common1[4];
+}

ld/testsuite/ld-elf/pr13250-3.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int common1[1];
+char common2[2];
+
+extern int bar ();
+
+int
+main ()
+{
+  int i;
+  if (bar () != -1)
+    abort ();
+  if (common1[0] != -1)
+    abort ();
+  for (i = 0; i < sizeof (common2)/ sizeof (common2[0]); i++)
+    if (common2[i] != 0)
+      abort ();
+  printf ("PASS\n");
+  return 0;
+}

ld/testsuite/ld-elf/shared.exp

@@ -157,6 +157,15 @@ set build_tests {
   {"Build libpr11138-2.o"
    "-r -nostdlib" ""
    {pr11138-2.c} {} "libpr11138-2.o"}
+  {"Build pr13250-1.so"
+   "-shared" "-fPIC"
+   {pr13250-1.c} {} "libpr13250-1.so"}
+  {"Build pr13250-2.so with libpr13250-1.so"
+   "-shared tmpdir/libpr13250-1.so" "-fPIC"
+   {pr13250-2.c} {} "libpr13250-2.so"}
+  {"Build libpr13250-3.o"
+   "-r -nostdlib" ""
+   {pr13250-3.c} {} "libpr13250-3.o"}
 }
 
 run_cc_link_tests $build_tests
@@ -283,6 +292,9 @@ set run_tests {
     {"Run with libpr11138-1.so pr11138-2.c"
      "--version-script=pr11138-2.map tmpdir/libpr11138-1.so tmpdir/pr11138-2.o" ""
      {dummy.c} "pr11138b" "pr11138.out"}
+    {"Run with pr13250-3.c, libpr13250-1.so and libpr13250-2.so"
+     "--as-needed tmpdir/pr13250-3.o tmpdir/libpr13250-1.so tmpdir/libpr13250-2.so" ""
+     {dummy.c} "pr13250" "pass.out"}
 }
 
 # NetBSD ELF systems do not currently support the .*_array sections.