PR ld/21900: MIPS: Fix relocation processing with undefined symbols

Currently, when `mips_elf_calculate_relocation' is asked to relocate an
undefined symbol, it reports an error or a warning and immediately
returns without performing the relocation.  This is fine if the link
fails, but if unresolved_syms_in_objects == RM_GENERATE_WARNING, the
link will continue and output some unrelocated code, which is a
regression from commit e7e2196da3f0 ("MIPS/BFD: Correctly report
undefined relocations").

Fix this by continuing after calling the `undefined_symbol' hook unless
this is an error condition.

	bfd/
	PR ld/21900
	* elfxx-mips.c (mips_elf_calculate_relocation): Only return
	after calling `undefined_symbol' hook if this is an error
	condition.  Assume the value of 0 for the symbol requested
	otherwise.

	ld/
	PR ld/21900
	* testsuite/ld-mips-elf/undefined-warn.d: New test.
	* testsuite/ld-mips-elf/undefined.s: Add padding at the end.
	* testsuite/ld-mips-elf/mips-elf.exp: Run the new test.

1 files changed, 10 insertions, 4 deletions

diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c
index 32b93fe7ad..ce645817bb 100644
--- a/bfd/elfxx-mips.c
+++ b/bfd/elfxx-mips.c
@@ -5478,12 +5478,18 @@ mips_elf_calculate_relocation (bfd *abfd, bfd *input_bfd,
 	}
       else
 	{
+	  bfd_boolean reject_undefined
+	    = (info->unresolved_syms_in_objects == RM_GENERATE_ERROR
+	       || ELF_ST_VISIBILITY (h->root.other) != STV_DEFAULT);
+
 	  (*info->callbacks->undefined_symbol)
 	    (info, h->root.root.root.string, input_bfd,
-	     input_section, relocation->r_offset,
-	     (info->unresolved_syms_in_objects == RM_GENERATE_ERROR)
-	     || ELF_ST_VISIBILITY (h->root.other));
-	  return bfd_reloc_undefined;
+	     input_section, relocation->r_offset, reject_undefined);
+
+	  if (reject_undefined)
+	    return bfd_reloc_undefined;
+
+	  symbol = 0;
 	}
 
       target_is_16_bit_code_p = ELF_ST_IS_MIPS16 (h->root.other);