Implement -z dynamic-undefined-weak

-z nodynamic-undefined-weak is only implemented for x86. (The sparc backend has some support code but doesn't enable the option by including ld/emulparams/dynamic_undefined_weak.sh, and since the support looks like it may be broken I haven't enabled it.) This patch adds the complementary -z dynamic-undefined-weak, extends both options to affect building of shared libraries as well as executables, and adds support for the option on powerpc. include/ * bfdlink.h (struct bfd_link_info <dynamic_undefined_weak>): Revise comment. bfd/ * elflink.c (_bfd_elf_adjust_dynamic_symbol): Hide undefweak or make dynamic for info->dynamic_undefined_weak 0 and 1. * elf32-ppc.c:Formatting. (ensure_undefweak_dynamic): Don't make dynamic when info->dynamic_undefined_weak is zero. (allocate_dynrelocs): Discard undefweak dyn_relocs for info->dynamic_undefined_weak. Discard undef dyn_relocs when not default visibility. Discard undef and undefweak dyn_relocs earlier. (ppc_elf_relocate_section): Adjust to suit. * elf64-ppc.c: Formatting. (ensure_undefweak_dynamic): Don't make dynamic when info->dynamic_undefined_weak is zero. (allocate_dynrelocs): Discard undefweak dyn_relocs for info->dynamic_undefined_weak. Discard them earlier. ld/ * ld.texinfo (dynamic-undefined-weak): Document. (nodynamic-undefined-weak): Document that this option now can be used with shared libs. * emulparams/dynamic_undefined_weak.sh: Support -z dynamic-undefined-weak. * emulparams/elf32ppccommon.sh: Include dynamic_undefined_weak.sh. * testsuite/ld-undefined/weak-undef.exp (undef_weak_so), (undef_weak_exe): New. Use them. Add -z dynamic-undefined-weak and -z nodynamic-undefined-weak tests. * Makefile.am: Update powerpc dependencies. * Makefile.in: Regenerate.
author: Alan Modra <amodra@gmail.com> 2017-04-19 01:26:57 +0930
committer: Alan Modra <amodra@gmail.com> 2017-04-19 20:39:52 +0930
commit: 954b63d4c8645f86e40c7ef6c6d60acd2bf019de (patch)
tree: 7e351a33b44fe2672265e418e9d3d4f9e38215d1
parent: 951787ed6d13f8f441d93fc3f6fb870c234774af (diff)
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13 files changed, 225 insertions, 78 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index f1ca8b4..b66ade6 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,21 @@
+2017-04-19  Alan Modra  <amodra@gmail.com>
+
+	* elflink.c (_bfd_elf_adjust_dynamic_symbol): Hide undefweak
+	or make dynamic for info->dynamic_undefined_weak 0 and 1.
+	* elf32-ppc.c:Formatting.
+	(ensure_undefweak_dynamic): Don't make dynamic when
+	info->dynamic_undefined_weak is zero.
+	(allocate_dynrelocs): Discard undefweak dyn_relocs for
+	info->dynamic_undefined_weak.  Discard undef dyn_relocs when
+	not default visibility.  Discard undef and undefweak
+	dyn_relocs earlier.
+	(ppc_elf_relocate_section): Adjust to suit.
+	* elf64-ppc.c: Formatting.
+	(ensure_undefweak_dynamic): Don't make dynamic when
+	info->dynamic_undefined_weak is zero.
+	(allocate_dynrelocs): Discard undefweak dyn_relocs for
+	info->dynamic_undefined_weak.  Discard them earlier.
+
 2017-04-17  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/21389
diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
index 4bd58e2..6a24a46 100644
--- a/bfd/elf32-ppc.c
+++ b/bfd/elf32-ppc.c
@@ -2609,7 +2609,7 @@ ppc_elf_modify_segment_map (bfd *abfd,
       amt += (m->count - j - 1) * sizeof (asection *);
       n = (struct elf_segment_map *) bfd_zalloc (abfd, amt);
       if (n == NULL)
-        return FALSE;
+	return FALSE;
 
       n->p_type = PT_LOAD;
       n->count = m->count - j;
@@ -5947,6 +5947,7 @@ ensure_undefweak_dynamic (struct bfd_link_info *info,
   struct elf_link_hash_table *htab = elf_hash_table (info);
 
   if (htab->dynamic_sections_created
+      && info->dynamic_undefined_weak != 0
       && h->root.type == bfd_link_hash_undefweak
       && h->dynindx == -1
       && !h->forced_local
@@ -6036,6 +6037,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
   else
     eh->elf.got.offset = (bfd_vma) -1;
 
+  /* If no dynamic sections we can't have dynamic relocs, except for
+     IFUNCs which are handled even in static executables.  */
   if (!htab->elf.dynamic_sections_created
       && h->type != STT_GNU_IFUNC)
     eh->dyn_relocs = NULL;
@@ -6050,13 +6053,25 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
      changes.  */
   else if (bfd_link_pic (info))
     {
+      /* Discard relocs on undefined symbols that must be local.  */
+      if (h->root.type == bfd_link_hash_undefined
+	  && ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
+	eh->dyn_relocs = NULL;
+
+      /* Also discard relocs on undefined weak syms with non-default
+	 visibility, or when dynamic_undefined_weak says so.  */
+      else if (h->root.type == bfd_link_hash_undefweak
+	       && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+		   || info->dynamic_undefined_weak == 0))
+	eh->dyn_relocs = NULL;
+
       /* Relocs that use pc_count are those that appear on a call insn,
 	 or certain REL relocs (see must_be_dyn_reloc) that can be
 	 generated via assembly.  We want calls to protected symbols to
 	 resolve directly to the function rather than going via the plt.
 	 If people want function pointer comparisons to work as expected
 	 then they should avoid writing weird assembly.  */
-      if (SYMBOL_CALLS_LOCAL (info, h))
+      else if (SYMBOL_CALLS_LOCAL (info, h))
 	{
 	  struct elf_dyn_relocs **pp;
 
@@ -6084,24 +6099,11 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 	    }
 	}
 
-      /* Discard relocs on undefined symbols that must be local.  */
-      if (eh->dyn_relocs != NULL
-	  && h->root.type == bfd_link_hash_undefined
-	  && (ELF_ST_VISIBILITY (h->other) == STV_HIDDEN
-	      || ELF_ST_VISIBILITY (h->other) == STV_INTERNAL))
-	eh->dyn_relocs = NULL;
-
-      /* Also discard relocs on undefined weak syms with non-default
-	 visibility.  */
-      if (eh->dyn_relocs != NULL
-	  && h->root.type == bfd_link_hash_undefweak)
+      if (eh->dyn_relocs != NULL)
 	{
-	  if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
-	    eh->dyn_relocs = NULL;
-
 	  /* Make sure undefined weak symbols are output as a dynamic
 	     symbol in PIEs.  */
-	  else if (!ensure_undefweak_dynamic (info, h))
+	  if (!ensure_undefweak_dynamic (info, h))
 	    return FALSE;
 	}
     }
@@ -8859,10 +8861,10 @@ ppc_elf_relocate_section (bfd *output_bfd,
 	  if ((bfd_link_pic (info)
 	       && !(h != NULL
 		    && ((h->root.type == bfd_link_hash_undefined
-			 && (ELF_ST_VISIBILITY (h->other) == STV_HIDDEN
-			     || ELF_ST_VISIBILITY (h->other) == STV_INTERNAL))
+			 && ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
 			|| (h->root.type == bfd_link_hash_undefweak
-			    && ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)))
+			    && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+				|| info->dynamic_undefined_weak == 0))))
 	       && (must_be_dyn_reloc (info, r_type)
 		   || !SYMBOL_CALLS_LOCAL (info, h)))
 	      || (ELIMINATE_COPY_RELOCS
@@ -10979,7 +10981,7 @@ ppc_elf_finish_dynamic_sections (bfd *output_bfd,
 #define elf_backend_finish_dynamic_sections	ppc_elf_finish_dynamic_sections
 #define elf_backend_fake_sections		ppc_elf_fake_sections
 #define elf_backend_additional_program_headers	ppc_elf_additional_program_headers
-#define elf_backend_modify_segment_map     	ppc_elf_modify_segment_map
+#define elf_backend_modify_segment_map		ppc_elf_modify_segment_map
 #define elf_backend_grok_prstatus		ppc_elf_grok_prstatus
 #define elf_backend_grok_psinfo			ppc_elf_grok_psinfo
 #define elf_backend_write_core_note		ppc_elf_write_core_note
@@ -11049,7 +11051,7 @@ ppc_elf_vxworks_link_hash_table_create (bfd *abfd)
   if (ret)
     {
       struct ppc_elf_link_hash_table *htab
-        = (struct ppc_elf_link_hash_table *)ret;
+	= (struct ppc_elf_link_hash_table *)ret;
       htab->is_vxworks = 1;
       htab->plt_type = PLT_VXWORKS;
       htab->plt_entry_size = VXWORKS_PLT_ENTRY_SIZE;
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index e48d67d..fc69964 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -9695,6 +9695,7 @@ ensure_undefweak_dynamic (struct bfd_link_info *info,
   struct elf_link_hash_table *htab = elf_hash_table (info);
 
   if (htab->dynamic_sections_created
+      && info->dynamic_undefined_weak != 0
       && h->root.type == bfd_link_hash_undefweak
       && h->dynindx == -1
       && !h->forced_local
@@ -9785,10 +9786,19 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 	allocate_got (h, info, gent);
       }
 
+  /* If no dynamic sections we can't have dynamic relocs, except for
+     IFUNCs which are handled even in static executables.  */
   if (!htab->elf.dynamic_sections_created
       && h->type != STT_GNU_IFUNC)
     eh->dyn_relocs = NULL;
 
+  /* Also discard relocs on undefined weak syms with non-default
+     visibility, or when dynamic_undefined_weak says so.  */
+  else if (h->root.type == bfd_link_hash_undefweak
+	   && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+	       || info->dynamic_undefined_weak == 0))
+    eh->dyn_relocs = NULL;
+
   if (eh->dyn_relocs != NULL)
     {
       struct elf_dyn_relocs *p, **pp;
@@ -9821,17 +9831,11 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 		}
 	    }
 
-	  /* Also discard relocs on undefined weak syms with
-	     non-default visibility.  */
-	  if (eh->dyn_relocs != NULL
-	      && h->root.type == bfd_link_hash_undefweak)
+	  if (eh->dyn_relocs != NULL)
 	    {
-	      if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
-		eh->dyn_relocs = NULL;
-
 	      /* Make sure this symbol is output as a dynamic symbol.
 		 Undefined weak syms won't yet be marked as dynamic.  */
-	      else if (!ensure_undefweak_dynamic (info, h))
+	      if (!ensure_undefweak_dynamic (info, h))
 		return FALSE;
 	    }
 	}
@@ -14320,7 +14324,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 	      addend = 0;
 	      reloc_dest = DEST_STUB;
 
- 	      if ((stub_entry->stub_type == ppc_stub_plt_call
+	      if ((stub_entry->stub_type == ppc_stub_plt_call
 		   || stub_entry->stub_type == ppc_stub_plt_call_r2save)
 		  && (ALWAYS_EMIT_R2SAVE
 		      || stub_entry->stub_type == ppc_stub_plt_call_r2save)
diff --git a/bfd/elflink.c b/bfd/elflink.c
index b93d4f3..0add01b 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -2803,6 +2803,24 @@ _bfd_elf_adjust_dynamic_symbol (struct elf_link_hash_entry *h, void *data)
   if (! _bfd_elf_fix_symbol_flags (h, eif))
     return FALSE;
 
+  if (h->root.type == bfd_link_hash_undefweak)
+    {
+      if (eif->info->dynamic_undefined_weak == 0)
+	_bfd_elf_link_hash_hide_symbol (eif->info, h, TRUE);
+      else if (eif->info->dynamic_undefined_weak > 0
+	       && h->ref_regular
+	       && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+	       && !bfd_hide_sym_by_version (eif->info->version_info,
+					    h->root.root.string))
+	{
+	  if (!bfd_elf_link_record_dynamic_symbol (eif->info, h))
+	    {
+	      eif->failed = TRUE;
+	      return FALSE;
+	    }
+	}
+    }
+
   /* If this symbol does not require a PLT entry, and it is not
      defined by a dynamic object, or is not referenced by a regular
      object, ignore it.  We do have to handle a weak defined symbol,
diff --git a/include/ChangeLog b/include/ChangeLog
index b0e30ab..90c4c8d 100644
--- a/include/ChangeLog
+++ b/include/ChangeLog
@@ -1,3 +1,8 @@
+2017-04-19  Alan Modra  <amodra@gmail.com>
+
+	* bfdlink.h (struct bfd_link_info <dynamic_undefined_weak>):
+	Revise comment.
+
 2017-04-11  Alan Modra  <amodra@gmail.com>
 
 	* opcode/ppc.h (PPC_OPCODE_ALTIVEC2): Delete.
diff --git a/include/bfdlink.h b/include/bfdlink.h
index 3835fcb..18dea0c 100644
--- a/include/bfdlink.h
+++ b/include/bfdlink.h
@@ -584,8 +584,9 @@ struct bfd_link_info
      backend to decide.  */
   int extern_protected_data;
 
-  /* > 0 to treat undefined weak symbol in the executable as dynamic,
-     requiring dynamic relocation.  */
+  /* 1 to make undefined weak symbols dynamic when building a dynamic
+     object.  0 to resolve undefined weak symbols to zero.  -1 to let
+     the backend decide.  */
   int dynamic_undefined_weak;
 
   /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
diff --git a/ld/ChangeLog b/ld/ChangeLog
index a5732a5..c20ed75 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,17 @@
+2017-04-19  Alan Modra  <amodra@gmail.com>
+
+	* ld.texinfo (dynamic-undefined-weak): Document.
+	(nodynamic-undefined-weak): Document that this option now can
+	be used with shared libs.
+	* emulparams/dynamic_undefined_weak.sh: Support -z
+	dynamic-undefined-weak.
+	* emulparams/elf32ppccommon.sh: Include dynamic_undefined_weak.sh.
+	* testsuite/ld-undefined/weak-undef.exp (undef_weak_so),
+	(undef_weak_exe): New.  Use them.  Add -z dynamic-undefined-weak
+	and -z nodynamic-undefined-weak tests.
+	* Makefile.am: Update powerpc dependencies.
+	* Makefile.in: Regenerate.
+
 2017-04-17  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/21389
diff --git a/ld/Makefile.am b/ld/Makefile.am
index 9dd31ff..3aa7e80 100644
--- a/ld/Makefile.am
+++ b/ld/Makefile.am
@@ -1157,23 +1157,27 @@ eelf32lmip.c: $(srcdir)/emulparams/elf32lmip.sh \
 eelf32lppc.c: $(srcdir)/emulparams/elf32lppc.sh \
   $(srcdir)/emulparams/elf32ppccommon.sh \
   $(srcdir)/emulparams/elf32ppc.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32lppclinux.c: $(srcdir)/emulparams/elf32lppclinux.sh \
   $(srcdir)/emulparams/elf32lppc.sh $(srcdir)/emulparams/elf32ppc.sh \
   $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32lppcnto.c: $(srcdir)/emulparams/elf32lppcnto.sh \
   $(srcdir)/emulparams/elf32ppc.sh $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32lppcsim.c: $(srcdir)/emulparams/elf32lppcsim.sh \
   $(srcdir)/emulparams/elf32lppc.sh $(srcdir)/emulparams/elf32ppc.sh \
   $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
@@ -1253,31 +1257,37 @@ eelf32or1k_linux.c: $(srcdir)/emulparams/elf32or1k_linux.sh \
 
 eelf32ppc.c: $(srcdir)/emulparams/elf32ppc.sh \
   $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32ppc_fbsd.c: $(srcdir)/emulparams/elf32ppc_fbsd.sh \
   $(srcdir)/emulparams/elf32ppc.sh $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32ppclinux.c: $(srcdir)/emulparams/elf32ppclinux.sh \
   $(srcdir)/emulparams/elf32ppc.sh $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32ppcnto.c: $(srcdir)/emulparams/elf32ppcnto.sh \
   $(srcdir)/emulparams/elf32ppc.sh $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32ppcsim.c: $(srcdir)/emulparams/elf32ppcsim.sh \
   $(srcdir)/emulparams/elf32ppc.sh $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32ppcvxworks.c: $(srcdir)/emulparams/elf32ppcvxworks.sh \
   $(srcdir)/emulparams/elf32ppccommon.sh $(srcdir)/emulparams/vxworks.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(srcdir)/emultempl/vxworks.em \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
@@ -1976,8 +1986,9 @@ eelf64hppa.c: $(srcdir)/emulparams/elf64hppa.sh \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf64hppa.sc ${GEN_DEPENDS}
 
 eelf64lppc.c: $(srcdir)/emulparams/elf64lppc.sh \
-  $(srcdir)/emulparams/elf64ppc.sh $(srcdir)/emultempl/ppc64elf.em \
-  ldemul-list.h \
+  $(srcdir)/emulparams/elf64ppc.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
+  $(srcdir)/emultempl/ppc64elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf64lriscv.c: $(srcdir)/emulparams/elf64lriscv.sh \
@@ -2000,11 +2011,13 @@ eelf64mmix.c: $(srcdir)/emulparams/elf64mmix.sh \
   $(ELF_DEPS) $(srcdir)/emultempl/mmix-elfnmmo.em \
   $(srcdir)/emultempl/mmixelf.em $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
-eelf64ppc.c: $(srcdir)/emulparams/elf64ppc.sh $(srcdir)/emultempl/ppc64elf.em \
-  ldemul-list.h \
+eelf64ppc.c: $(srcdir)/emulparams/elf64ppc.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
+  $(srcdir)/emultempl/ppc64elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf64ppc_fbsd.c: $(srcdir)/emulparams/elf64ppc_fbsd.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc64elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
diff --git a/ld/Makefile.in b/ld/Makefile.in
index c464302..f485f4f 100644
--- a/ld/Makefile.in
+++ b/ld/Makefile.in
@@ -2721,23 +2721,27 @@ eelf32lmip.c: $(srcdir)/emulparams/elf32lmip.sh \
 eelf32lppc.c: $(srcdir)/emulparams/elf32lppc.sh \
   $(srcdir)/emulparams/elf32ppccommon.sh \
   $(srcdir)/emulparams/elf32ppc.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32lppclinux.c: $(srcdir)/emulparams/elf32lppclinux.sh \
   $(srcdir)/emulparams/elf32lppc.sh $(srcdir)/emulparams/elf32ppc.sh \
   $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32lppcnto.c: $(srcdir)/emulparams/elf32lppcnto.sh \
   $(srcdir)/emulparams/elf32ppc.sh $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32lppcsim.c: $(srcdir)/emulparams/elf32lppcsim.sh \
   $(srcdir)/emulparams/elf32lppc.sh $(srcdir)/emulparams/elf32ppc.sh \
   $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
@@ -2817,31 +2821,37 @@ eelf32or1k_linux.c: $(srcdir)/emulparams/elf32or1k_linux.sh \
 
 eelf32ppc.c: $(srcdir)/emulparams/elf32ppc.sh \
   $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32ppc_fbsd.c: $(srcdir)/emulparams/elf32ppc_fbsd.sh \
   $(srcdir)/emulparams/elf32ppc.sh $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32ppclinux.c: $(srcdir)/emulparams/elf32ppclinux.sh \
   $(srcdir)/emulparams/elf32ppc.sh $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32ppcnto.c: $(srcdir)/emulparams/elf32ppcnto.sh \
   $(srcdir)/emulparams/elf32ppc.sh $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32ppcsim.c: $(srcdir)/emulparams/elf32ppcsim.sh \
   $(srcdir)/emulparams/elf32ppc.sh $(srcdir)/emulparams/elf32ppccommon.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf32ppcvxworks.c: $(srcdir)/emulparams/elf32ppcvxworks.sh \
   $(srcdir)/emulparams/elf32ppccommon.sh $(srcdir)/emulparams/vxworks.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc32elf.em ldemul-list.h \
   $(srcdir)/emultempl/vxworks.em \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
@@ -3540,8 +3550,9 @@ eelf64hppa.c: $(srcdir)/emulparams/elf64hppa.sh \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf64hppa.sc ${GEN_DEPENDS}
 
 eelf64lppc.c: $(srcdir)/emulparams/elf64lppc.sh \
-  $(srcdir)/emulparams/elf64ppc.sh $(srcdir)/emultempl/ppc64elf.em \
-  ldemul-list.h \
+  $(srcdir)/emulparams/elf64ppc.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
+  $(srcdir)/emultempl/ppc64elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf64lriscv.c: $(srcdir)/emulparams/elf64lriscv.sh \
@@ -3564,11 +3575,13 @@ eelf64mmix.c: $(srcdir)/emulparams/elf64mmix.sh \
   $(ELF_DEPS) $(srcdir)/emultempl/mmix-elfnmmo.em \
   $(srcdir)/emultempl/mmixelf.em $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
-eelf64ppc.c: $(srcdir)/emulparams/elf64ppc.sh $(srcdir)/emultempl/ppc64elf.em \
-  ldemul-list.h \
+eelf64ppc.c: $(srcdir)/emulparams/elf64ppc.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
+  $(srcdir)/emultempl/ppc64elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf64ppc_fbsd.c: $(srcdir)/emulparams/elf64ppc_fbsd.sh \
+  $(srcdir)/emulparams/dynamic_undefined_weak.sh \
   $(srcdir)/emultempl/ppc64elf.em ldemul-list.h \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
diff --git a/ld/emulparams/dynamic_undefined_weak.sh b/ld/emulparams/dynamic_undefined_weak.sh
index 82d88d6..a20bbd4 100644
--- a/ld/emulparams/dynamic_undefined_weak.sh
+++ b/ld/emulparams/dynamic_undefined_weak.sh
@@ -1,12 +1,15 @@
-PARSE_AND_LIST_OPTIONS_NODYNAMIC_UNDEFINED_WEAK='
+PARSE_AND_LIST_OPTIONS_DYNAMIC_UNDEFINED_WEAK='
   fprintf (file, _("\
-  -z nodynamic-undefined-weak Do not treat undefined weak symbol as dynamic\n"));
+  -z dynamic-undefined-weak   Make undefined weak symbols dynamic\n\
+  -z nodynamic-undefined-weak Do not make undefined weak symbols dynamic\n"));
 '
 
-PARSE_AND_LIST_ARGS_CASE_Z_NODYNAMIC_UNDEFINED_WEAK='
+PARSE_AND_LIST_ARGS_CASE_Z_DYNAMIC_UNDEFINED_WEAK='
+      else if (strcmp (optarg, "dynamic-undefined-weak") == 0)
+	link_info.dynamic_undefined_weak = TRUE;
       else if (strcmp (optarg, "nodynamic-undefined-weak") == 0)
 	link_info.dynamic_undefined_weak = FALSE;
 '
 
-PARSE_AND_LIST_OPTIONS="$PARSE_AND_LIST_OPTIONS $PARSE_AND_LIST_OPTIONS_NODYNAMIC_UNDEFINED_WEAK"
-PARSE_AND_LIST_ARGS_CASE_Z="$PARSE_AND_LIST_ARGS_CASE_Z $PARSE_AND_LIST_ARGS_CASE_Z_NODYNAMIC_UNDEFINED_WEAK"
+PARSE_AND_LIST_OPTIONS="$PARSE_AND_LIST_OPTIONS $PARSE_AND_LIST_OPTIONS_DYNAMIC_UNDEFINED_WEAK"
+PARSE_AND_LIST_ARGS_CASE_Z="$PARSE_AND_LIST_ARGS_CASE_Z $PARSE_AND_LIST_ARGS_CASE_Z_DYNAMIC_UNDEFINED_WEAK"
diff --git a/ld/emulparams/elf32ppccommon.sh b/ld/emulparams/elf32ppccommon.sh
index d00cf68..44edbd0 100644
--- a/ld/emulparams/elf32ppccommon.sh
+++ b/ld/emulparams/elf32ppccommon.sh
@@ -1,5 +1,7 @@
 # The PLT-agnostic parts of a generic 32-bit ELF PowerPC target.  Included by:
 # elf32ppc.sh elf32ppcvxworks.sh elf64ppc.sh
+. ${srcdir}/emulparams/dynamic_undefined_weak.sh
+
 TEMPLATE_NAME=elf32
 GENERATE_SHLIB_SCRIPT=yes
 GENERATE_PIE_SCRIPT=yes
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index 909342c..2626b5d 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -1231,11 +1231,18 @@ generated by compiler.  Updates on protected data symbols by another
 module aren't visible to the resulting shared library.  Supported for
 i386 and x86-64.
 
+@item dynamic-undefined-weak
+Make undefined weak symbols dynamic when building a dynamic object,
+if they are referenced from a regular object file and not forced local
+by symbol visibility or versioning.  Not all targets support this
+option.
+
 @item nodynamic-undefined-weak
-Don't treat undefined weak symbols as dynamic when building executable.
-This option overrides linker backend default.  It can be used to avoid
-dynamic relocations against undefined weak symbols in executable.
-Supported for i386 and x86-64.
+Do not make undefined weak symbols dynamic when building a dynamic
+object.  Not all targets support this option.  If neither
+@option{-z nodynamic-undefined-weak} nor @option{-z dynamic-undefined-weak}
+are given, a target may default to either option being in force, or
+make some other selection of undefined weak symbols dynamic.
 
 @item noreloc-overflow
 Disable relocation overflow check.  This can be used to disable
diff --git a/ld/testsuite/ld-undefined/weak-undef.exp b/ld/testsuite/ld-undefined/weak-undef.exp
index eb28c2c..4ae22cf 100644
--- a/ld/testsuite/ld-undefined/weak-undef.exp
+++ b/ld/testsuite/ld-undefined/weak-undef.exp
@@ -53,6 +53,52 @@ if { ![is_elf_format] && ![is_pecoff_format] } then {
     }
 }
 
+proc undef_weak_so { testname opts passval } {
+    global ld
+    global nm
+
+    if {![ld_link $ld tmpdir/weak-fundef.so \
+	  "$opts tmpdir/weak-fundef.o"]} then {
+	fail $testname
+    } elseif {![is_remote host] && [which $nm] == 0} then {
+	unresolved $testname
+    } else {
+	set exec_output [run_host_cmd "$nm" "-D tmpdir/weak-fundef.so"]
+	set exec_output [prune_warnings $exec_output]
+
+	set output_regexp ".*w undef_weak_fun.*"
+	if {[regexp $output_regexp $exec_output] == $passval} then {
+	    pass $testname
+	} else {
+	    fail $testname
+	}
+	return 1
+    }
+    return 0
+}
+
+proc undef_weak_exe { testname opts passval } {
+    global ld
+    global nm
+
+    if {![ld_link $ld tmpdir/weak-fundef \
+	  "$opts tmpdir/weak-fundef.o tmpdir/weak-fundef.so"]} then {
+	fail $testname
+    } elseif {![is_remote host] && [which $nm] == 0} then {
+	unresolved $testname
+    } else {
+	set exec_output [run_host_cmd "$nm" "-D tmpdir/weak-fundef"]
+	set exec_output [prune_warnings $exec_output]
+
+	set output_regexp ".*w undef_weak_fun.*"
+	if {[regexp $output_regexp $exec_output] == $passval} then {
+	    pass $testname
+	} else {
+	    fail $testname
+	}
+    }
+}
+
 # When linking a shared lib, weak undefined symbols should become dynamic.
 set testname "weak undefined function symbols in shared lib"
 
@@ -71,39 +117,40 @@ if { $asflags == "" || ![is_elf_format] || ![check_shared_lib_support]} then {
 } elseif {![ld_assemble $as "$asflags $srcdir/$subdir/weak-fundef.s" \
 		tmpdir/weak-fundef.o]} then {
     fail $testname
-} elseif {![ld_link $ld tmpdir/weak-fundef.so \
-	    "--shared tmpdir/weak-fundef.o"]} then {
-    fail $testname
-} elseif {![is_remote host] && [which $nm] == 0} then {
-    unresolved $testname
-} else {
-    set exec_output [run_host_cmd "$nm" "-D tmpdir/weak-fundef.so"]
-    set exec_output [prune_warnings $exec_output]
-    verbose -log $exec_output
+} elseif { [undef_weak_so $testname "--shared" 1] } then {
 
-    set output_regexp ".*w undef_weak_fun.*"
+    # When linking a dynamic executable, weak undefined symbols become dynamic.
+    set testname "weak undefined function symbols in dynamic exe"
+    undef_weak_exe $testname "--no-as-needed" 1
 
-    if {[regexp $output_regexp $exec_output]} then {
-	pass $testname
-    } else {
-	fail $testname
+    # Find -z options supported by the default emulation
+    set emul [get_target_emul]
+    set cmd [list "$ld --help 2>&1 | sed -e '1,/^$emul:/d;/^\[^ \]*:/,\$d'"]
+    set status [remote_exec host [concat sh -c $cmd]]
+    if { [lindex $status 0] != 0 } {
+	verbose -log "$cmd exited with status [lindex $status 0]"
     }
+    set emulopt [lindex $status 1]
 
-    # When linking a dynamic executable, weak undefined symbols become dynamic.
-    set testname "weak undefined function symbols in dynamic exe"
+    if { [string first "dynamic-undefined-weak" $emulopt] >= 0 } {
+	# -z dynamic-undefined-weak is supported.  Let's see if it works.
 
-    if {![ld_link $ld tmpdir/weak-fundef \
-	  "--no-as-needed tmpdir/weak-fundef.o tmpdir/weak-fundef.so"]} then {
-	fail $testname
-    } else {
-	set exec_output [run_host_cmd "$nm" "-D tmpdir/weak-fundef"]
-	set exec_output [prune_warnings $exec_output]
-	verbose -log $exec_output
+	set testname "weak undefined functions in shared lib, no dyn undef weak"
+	undef_weak_so $testname "--shared -z nodynamic-undefined-weak" 0
 
-	if {[regexp $output_regexp $exec_output]} then {
-	    pass $testname
-	} else {
-	    fail $testname
-	}
+	set testname "weak undefined functions in shared lib, dyn undef weak"
+	undef_weak_so $testname "--shared -z dynamic-undefined-weak" 1
+
+	set testname "weak undefined functions in dynamic exe, no dyn undef weak"
+	undef_weak_exe $testname "-z nodynamic-undefined-weak" 0
+
+	set testname "weak undefined functions in dynamic exe, dyn undef weak"
+	undef_weak_exe $testname "-z dynamic-undefined-weak" 1
+
+	set testname "weak undefined functions in pie, no dyn undef weak"
+	undef_weak_exe $testname "-pie -z nodynamic-undefined-weak" 0
+
+	set testname "weak undefined functions in pie, dyn undef weak"
+	undef_weak_exe $testname "-pie -z dynamic-undefined-weak" 1
     }
 }
author	Alan Modra <amodra@gmail.com>	2017-04-19 01:26:57 +0930
committer	Alan Modra <amodra@gmail.com>	2017-04-19 20:39:52 +0930
commit	954b63d4c8645f86e40c7ef6c6d60acd2bf019de (patch)
tree	7e351a33b44fe2672265e418e9d3d4f9e38215d1
parent	951787ed6d13f8f441d93fc3f6fb870c234774af (diff)
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