[SPARC] Fix PR/18841

[Eric Botcazou <ebotcazou at adacore dot com>]

Hi,

this fixes the last ld failures on SPARC64/Linux:

FAIL: Run pr18841 with libpr18841b.so
FAIL: Run pr18841 with libpr18841c.so
FAIL: Run pr18841 with libpr18841bn.so (-z now)
FAIL: Run pr18841 with libpr18841cn.so (-z now)

by mimicing what has been done on x86-64 and Aarch64 to fix the PR.

Tested on SPARC64/Linux, OK for mainline, 2.32 and 2.31 branches?


2019-01-29  Eric Botcazou  <ebotcazou@adacore.com>

bfd/
	PR ld/18841
	* elf32-sparc.c (elf32_sparc_reloc_type_class): Return
	reloc_class_ifunc for ifunc symbols.
	* elf64-sparc.c (elf64_sparc_reloc_type_class): Likewise.

-- 
Eric Botcazou

diff --git a/bfd/elf32-sparc.c b/bfd/elf32-sparc.c
index 1873b1ae7cc..f5c58630686 100644
--- a/bfd/elf32-sparc.c
+++ b/bfd/elf32-sparc.c
@@ -157,13 +157,44 @@ elf32_sparc_final_write_processing (bfd *abfd,
     }
 }
 
+/* Used to decide how to sort relocs in an optimal manner for the
+   dynamic linker, before writing them out.  */
+
 static enum elf_reloc_type_class
-elf32_sparc_reloc_type_class (const struct bfd_link_info *info ATTRIBUTE_UNUSED,
+elf32_sparc_reloc_type_class (const struct bfd_link_info *info,
 			      const asection *rel_sec ATTRIBUTE_UNUSED,
 			      const Elf_Internal_Rela *rela)
 {
+  bfd *abfd = info->output_bfd;
+  const struct elf_backend_data *bed = get_elf_backend_data (abfd);
+  struct _bfd_sparc_elf_link_hash_table *htab
+    = _bfd_sparc_elf_hash_table (info);
+  BFD_ASSERT (htab != NULL);
+
+  if (htab->elf.dynsym != NULL
+      && htab->elf.dynsym->contents != NULL)
+    {
+      /* Check relocation against STT_GNU_IFUNC symbol if there are
+	 dynamic symbols.  */
+      unsigned long r_symndx = htab->r_symndx (rela->r_info);
+      if (r_symndx != STN_UNDEF)
+	{
+	  Elf_Internal_Sym sym;
+	  if (!bed->s->swap_symbol_in (abfd,
+				       (htab->elf.dynsym->contents
+					+ r_symndx * bed->s->sizeof_sym),
+				       0, &sym))
+	    abort ();
+
+	  if (ELF_ST_TYPE (sym.st_info) == STT_GNU_IFUNC)
+	    return reloc_class_ifunc;
+	}
+    }
+
   switch ((int) ELF32_R_TYPE (rela->r_info))
     {
+    case R_SPARC_IRELATIVE:
+      return reloc_class_ifunc;
     case R_SPARC_RELATIVE:
       return reloc_class_relative;
     case R_SPARC_JMP_SLOT:
diff --git a/bfd/elf64-sparc.c b/bfd/elf64-sparc.c
index 7de32c91926..bd29be3a93c 100644
--- a/bfd/elf64-sparc.c
+++ b/bfd/elf64-sparc.c
@@ -769,13 +769,44 @@ elf64_sparc_print_symbol_all (bfd *abfd ATTRIBUTE_UNUSED, void * filep,
     return symbol->name;
 }
 
+/* Used to decide how to sort relocs in an optimal manner for the
+   dynamic linker, before writing them out.  */
+
 static enum elf_reloc_type_class
-elf64_sparc_reloc_type_class (const struct bfd_link_info *info ATTRIBUTE_UNUSED,
+elf64_sparc_reloc_type_class (const struct bfd_link_info *info,
 			      const asection *rel_sec ATTRIBUTE_UNUSED,
 			      const Elf_Internal_Rela *rela)
 {
+  bfd *abfd = info->output_bfd;
+  const struct elf_backend_data *bed = get_elf_backend_data (abfd);
+  struct _bfd_sparc_elf_link_hash_table *htab
+    = _bfd_sparc_elf_hash_table (info);
+  BFD_ASSERT (htab != NULL);
+
+  if (htab->elf.dynsym != NULL
+      && htab->elf.dynsym->contents != NULL)
+    {
+      /* Check relocation against STT_GNU_IFUNC symbol if there are
+	 dynamic symbols.  */
+      unsigned long r_symndx = htab->r_symndx (rela->r_info);
+      if (r_symndx != STN_UNDEF)
+	{
+	  Elf_Internal_Sym sym;
+	  if (!bed->s->swap_symbol_in (abfd,
+				       (htab->elf.dynsym->contents
+					+ r_symndx * bed->s->sizeof_sym),
+				       0, &sym))
+	    abort ();
+
+	  if (ELF_ST_TYPE (sym.st_info) == STT_GNU_IFUNC)
+	    return reloc_class_ifunc;
+	}
+    }
+
   switch ((int) ELF64_R_TYPE (rela->r_info))
     {
+    case R_SPARC_IRELATIVE:
+      return reloc_class_ifunc;
     case R_SPARC_RELATIVE:
       return reloc_class_relative;
     case R_SPARC_JMP_SLOT: