[committed v2] BFD/XCOFF: Fix storage class setting for weak defined symbols

[Maciej W. Rozycki]

Fix an issue with commit 8602d4fea60d ("Add AIX weak support"), 
<https://sourceware.org/ml/binutils/2009-03/msg00189.html>, and use the 
correct condition to set the storage class for weak defined symbols.

The context here is as follows:

  else if ((h->root.type == bfd_link_hash_defined
            || h->root.type == bfd_link_hash_defweak)
           && h->smclas == XMC_XO)
    {
      BFD_ASSERT (bfd_is_abs_section (h->root.u.def.section));
      isym.n_value = h->root.u.def.value;
      isym.n_scnum = N_UNDEF;
      if (h->root.type == bfd_link_hash_undefweak
          && C_WEAKEXT == C_AIX_WEAKEXT)
        isym.n_sclass = C_WEAKEXT;
      else
        isym.n_sclass = C_EXT;
      aux.x_csect.x_smtyp = XTY_ER;
    }

so clearly the inner condition can never be true.  Correct the condition 
then to check for the `bfd_link_hash_defweak' symbol type instead here, 
and in a similar place a little further down in the same function.

	bfd/
	* xcofflink.c (xcoff_write_global_symbol): Fix symbol type 
	checks for defined weak symbols.
---
Hi Alan,

> There's another instance of the same error 66 lines after this one.
> I think both count as obvious fixes.

 Well-spotted, thanks; I didn't check elsewhere.  This is the version I 
have applied.  Thanks for your review.

  Maciej
---
 bfd/xcofflink.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

binutils-bfd-xcofflink-write-global-symbol-weakext.diff
Index: binutils/bfd/xcofflink.c
===================================================================
--- binutils.orig/bfd/xcofflink.c	2018-07-17 21:25:14.468400816 +0100
+++ binutils/bfd/xcofflink.c	2018-07-18 12:10:16.292112596 +0100
@@ -5589,7 +5589,7 @@ xcoff_write_global_symbol (struct bfd_ha
       BFD_ASSERT (bfd_is_abs_symbol (&h->root));
       isym.n_value = h->root.u.def.value;
       isym.n_scnum = N_UNDEF;
-      if (h->root.type == bfd_link_hash_undefweak
+      if (h->root.type == bfd_link_hash_defweak
 	  && C_WEAKEXT == C_AIX_WEAKEXT)
 	isym.n_sclass = C_WEAKEXT;
       else
@@ -5655,7 +5655,7 @@ xcoff_write_global_symbol (struct bfd_ha
       /* We just output an SD symbol.  Now output an LD symbol.  */
       h->indx += 2;
 
-      if (h->root.type == bfd_link_hash_undefweak
+      if (h->root.type == bfd_link_hash_defweak
 	  && C_WEAKEXT == C_AIX_WEAKEXT)
 	isym.n_sclass = C_WEAKEXT;
       else