[binutils-gdb] Re: PR26978, Inconsistency for strong foo@v1 and weak foo@@v1

[binutils-gdb] Re: PR26978, Inconsistency for strong foo@v1 and weak foo@@v1

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=248b6326a49ed49e2f627d3bddbac514a074bac0

commit 248b6326a49ed49e2f627d3bddbac514a074bac0
Author: Alan Modra <amodra@gmail.com>
Date:   Mon Apr 8 08:16:20 2024 +0930

    Re: PR26978, Inconsistency for strong foo@v1 and weak foo@@v1
    
    Commit 726d7d1ecf opened a hole that allowed a u.i.link loop to be
    created, resulting in _bfd_generic_link_add_one_symbol never
    returning.  Fix that.  Note that the MIND case handles two types of
    redefinition.  For a new indirect symbol we'll have string non-NULL.
    For a new def, string will be NULL.  So moving the string comparison
    earlier would work.  However, we've already looked up inh in the first
    case so can dispense with name comparisons.  Either way, for a new def
    we'll get to the defweak test and possibly cycle.  Which is what we
    want here.
    
            PR 31615
            PR 26978
            * linker.c (_bfd_generic_link_add_one_symbol <MIND>): Test for
            exactly matching indirect symbols before cycling on a defweak.

Diff:
---
 bfd/linker.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/bfd/linker.c b/bfd/linker.c
index eb42a78b622..111deecf55d 100644
--- a/bfd/linker.c
+++ b/bfd/linker.c
@@ -1678,6 +1678,8 @@ _bfd_generic_link_add_one_symbol (struct bfd_link_info *info,
 	case MIND:
 	  /* Multiple indirect symbols.  This is OK if they both point
 	     to the same symbol.  */
+	  if (h->u.i.link == inh)
+	    break;
 	  if (h->u.i.link->type == bfd_link_hash_defweak)
 	    {
 	      /* It is also OK to redefine a symbol that indirects to
@@ -1689,8 +1691,6 @@ _bfd_generic_link_add_one_symbol (struct bfd_link_info *info,
 	      cycle = true;
 	      break;
 	    }
-	  if (string != NULL && strcmp (h->u.i.link->root.string, string) == 0)
-	    break;
 	  /* Fall through.  */
 	case MDEF:
 	  /* Handle a multiple definition.  */