add symbol qualifiers for mach-o to bfd/gas

bfd:

	* mach-o.c (bfd_mach_o_bfd_copy_private_symbol_data): Implement.
	(bfd_mach_o_write_symtab): Remove handling for indirect syms.
	(bfd_mach_o_primary_symbol_sort_key): Likewise.
	(bfd_mach_o_cf_symbols): Likewise.
	(bfd_mach_o_sort_symbol_table): Remove.
	(bfd_mach_o_mangle_symbols): Adjust arguments, remove handling
	for indirect and dysymtab counts.  Do the symbol sorting here.
	(bfd_mach_o_build_dysymtab_command): Count the symbol types here.
	Make the indirect symbols a TODO.
	(bfd_mach_o_build_commands): Adjust call to bfd_mach_o_mangle_symbols.
	(bfd_mach_o_make_empty_symbol): Specifically flag unset symbols with
	a non-zero value.
	(bfd_mach_o_read_symtab_symbol): Record the symbol index.
	(bfd_mach_o_read_symtab_symbol): Adjust recording of global status.
	* mach-o.h (mach_o_data_struct): Remove indirect and dysymtab entries.
	(IS_MACHO_INDIRECT): Remove.
	(SYM_MACHO_FIELDS_UNSET, SYM_MACHO_FIELDS_NOT_VALIDATED): New.

gas:

	* config/obj-macho.c (obj_mach_o_weak): Remove.
	(obj_mach_o_common_parse): Set symbol qualifiers.
	(LAZY, REFE): New macros.
	(obj_mach_o_symbol_type): New enum.
	(obj_mach_o_set_symbol_qualifier): New.
	(obj_mach_o_sym_qual): New.
	(mach_o_pseudo_table): Add symbol qualifiers, set indirect_symbol to
	a dummy function.
	(obj_mach_o_type_for_symbol): New.
	(obj_macho_frob_label): New.
	(obj_macho_frob_symbol): New.
	* config/obj-macho.h (S_SET_ALIGN): Amend temorary var name.
	(obj_frob_label, obj_macho_frob_label): Declare.
	(obj_frob_symbol, obj_macho_frob_symbol): Declare.

gas/testsuite:

	* gas/mach-o/err-syms-1.s: New.
	* gas/mach-o/err-syms-2.s: New.
	* gas/mach-o/err-syms-3.s: New.
	* gas/mach-o/symbols-2.d: New.
	* gas/mach-o/symbols-2.s: New.
	* gas/mach-o/symbols-3.s: New.
	* gas/mach-o/symbols-4.s: New.
	* gas/mach-o/symbols-5.d: New.
	* gas/mach-o/symbols-5.s: New.

13 files changed, 633 insertions, 34 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index c905439..1d72c39 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,20 @@
+2012-01-09  Iain Sandoe  <idsandoe@googlemail.com>
+
+	* config/obj-macho.c (obj_mach_o_weak): Remove.
+	(obj_mach_o_common_parse): Set symbol qualifiers.
+	(LAZY, REFE): New macros.
+	(obj_mach_o_symbol_type): New enum.
+	(obj_mach_o_set_symbol_qualifier): New.
+	(obj_mach_o_sym_qual): New.
+	(mach_o_pseudo_table): Add symbol qualifiers, set indirect_symbol to
+	a dummy function.
+	(obj_mach_o_type_for_symbol): New.
+	(obj_macho_frob_label): New.
+	(obj_macho_frob_symbol): New.
+	* config/obj-macho.h (S_SET_ALIGN): Amend temorary var name.
+	(obj_frob_label, obj_macho_frob_label): Declare.
+	(obj_frob_symbol, obj_macho_frob_symbol): Declare.
+
 2012-01-08  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	* config/tc-mips.c (s_tls_rel_directive): Call mips_clear_insn_labels.
diff --git a/gas/config/obj-macho.c b/gas/config/obj-macho.c
index b523767..43f4fba 100644
--- a/gas/config/obj-macho.c
+++ b/gas/config/obj-macho.c
@@ -82,33 +82,8 @@ mach_o_begin (void)
 
 /* Remember the subsections_by_symbols state in case we need to reset
    the file flags.  */
-static int obj_mach_o_subsections_by_symbols;
 
-static void
-obj_mach_o_weak (int ignore ATTRIBUTE_UNUSED)
-{
-  char *name;
-  int c;
-  symbolS *symbolP;
-
-  do
-    {
-      /* Get symbol name.  */
-      name = input_line_pointer;
-      c = get_symbol_end ();
-      symbolP = symbol_find_or_make (name);
-      S_SET_WEAK (symbolP);
-      *input_line_pointer = c;
-      SKIP_WHITESPACE ();
-
-      if (c != ',')
-        break;
-      input_line_pointer++;
-      SKIP_WHITESPACE ();
-    }
-  while (*input_line_pointer != '\n');
-  demand_empty_rest_of_line ();
-}
+static int obj_mach_o_subsections_by_symbols;
 
 /* This will put at most 16 characters (terminated by a ',' or newline) from
    the input stream into dest.  If there are more than 16 chars before the
@@ -901,6 +876,7 @@ obj_mach_o_common_parse (int is_local, symbolS *symbolP,
 			 addressT size)
 {
   addressT align = 0;
+  bfd_mach_o_asymbol *s;
 
   SKIP_WHITESPACE ();  
 
@@ -920,6 +896,7 @@ obj_mach_o_common_parse (int is_local, symbolS *symbolP,
 	}
     }
 
+  s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (symbolP);
   if (is_local)
     {
       /* Create the BSS section on demand.  */
@@ -929,6 +906,7 @@ obj_mach_o_common_parse (int is_local, symbolS *symbolP,
 	  seg_info (bss_section)->bss = 1;	  
 	}
       bss_alloc (symbolP, size, align);
+      s->n_type = BFD_MACH_O_N_SECT;
       S_CLEAR_EXTERNAL (symbolP);
     }
   else
@@ -937,9 +915,14 @@ obj_mach_o_common_parse (int is_local, symbolS *symbolP,
       S_SET_ALIGN (symbolP, align);
       S_SET_EXTERNAL (symbolP);
       S_SET_SEGMENT (symbolP, bfd_com_section_ptr);
+      s->n_type = BFD_MACH_O_N_UNDF | BFD_MACH_O_N_EXT;
     }
 
-  symbol_get_bfdsym (symbolP)->flags |= BSF_OBJECT;
+  /* This is a data object (whatever we choose that to mean).  */
+  s->symbol.flags |= BSF_OBJECT;
+
+  /* We've set symbol qualifiers, so validate if you can.  */
+  s->symbol.udata.i = SYM_MACHO_FIELDS_NOT_VALIDATED;
 
   return symbolP;
 }
@@ -979,6 +962,175 @@ obj_mach_o_fileprop (int prop)
     }
 }
 
+/* Temporary markers for symbol reference data.  
+   Lazy will remain in place.  */
+#define LAZY 0x01
+#define REFE 0x02
+
+/* We have a bunch of qualifiers that may be applied to symbols.
+   .globl is handled here so that we might make sure that conflicting qualifiers
+   are caught where possible.  */
+
+typedef enum obj_mach_o_symbol_type {
+  OBJ_MACH_O_SYM_UNK = 0,
+  OBJ_MACH_O_SYM_LOCAL = 1,
+  OBJ_MACH_O_SYM_GLOBL = 2,
+  OBJ_MACH_O_SYM_REFERENCE = 3,
+  OBJ_MACH_O_SYM_WEAK_REF = 4,
+  OBJ_MACH_O_SYM_LAZY_REF = 5,
+  OBJ_MACH_O_SYM_WEAK_DEF = 6,
+  OBJ_MACH_O_SYM_PRIV_EXT = 7,
+  OBJ_MACH_O_SYM_NO_DEAD_STRIP = 8,
+  OBJ_MACH_O_SYM_WEAK = 9
+} obj_mach_o_symbol_type;
+
+/* Set Mach-O-specific symbol qualifiers. */
+
+static int
+obj_mach_o_set_symbol_qualifier (symbolS *sym, int type)
+{
+  int is_defined;
+  bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (sym);
+  bfd_mach_o_section *sec;
+  int sectype = -1;
+  int err = 0;
+
+  /* If the symbol is defined, then we can do more rigorous checking on
+     the validity of the qualifiers.  Otherwise, we are stuck with waiting 
+     until it's defined - or until write the file.
+     
+     In certain cases (e.g. when a symbol qualifier is intended to introduce
+     an undefined symbol in a stubs section) we should check that the current
+     section is appropriate to the qualifier.  */
+
+  is_defined = s->symbol.section != bfd_und_section_ptr;
+  if (is_defined)
+    sec = bfd_mach_o_get_mach_o_section (s->symbol.section) ;
+  else
+    sec = bfd_mach_o_get_mach_o_section (now_seg) ;
+
+  if (sec != NULL)
+    sectype = sec->flags & BFD_MACH_O_SECTION_TYPE_MASK;
+
+  switch ((obj_mach_o_symbol_type) type)
+    {
+      case OBJ_MACH_O_SYM_LOCAL:
+	/* This is an extension over the system tools.  */
+        if (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT))
+	  {
+	    as_bad (_("'%s' previously declared as '%s'."), s->symbol.name,
+		      (s->n_type & BFD_MACH_O_N_PEXT) ? "private extern"
+						      : "global" );
+	    err = 1;
+	  }
+	else
+	  {
+	    s->n_type &= ~BFD_MACH_O_N_EXT;
+	    S_CLEAR_EXTERNAL (sym);
+	  }
+	break;
+
+      case OBJ_MACH_O_SYM_PRIV_EXT:
+	s->n_type |= BFD_MACH_O_N_PEXT ;
+	/* We follow the system tools in marking PEXT as also global.  */
+	/* Fall through.  */
+
+      case OBJ_MACH_O_SYM_GLOBL:
+	/* It's not an error to define a symbol and then make it global.  */
+	s->n_type |= BFD_MACH_O_N_EXT;
+	S_SET_EXTERNAL (sym);
+	break;
+
+      case OBJ_MACH_O_SYM_REFERENCE:
+        if (is_defined)
+          s->n_desc |= BFD_MACH_O_N_NO_DEAD_STRIP;
+        else
+          s->n_desc |= (REFE | BFD_MACH_O_N_NO_DEAD_STRIP);
+	break;
+
+      case OBJ_MACH_O_SYM_LAZY_REF:
+        if (is_defined)
+          s->n_desc |= BFD_MACH_O_N_NO_DEAD_STRIP;
+        else
+          s->n_desc |= (REFE | LAZY | BFD_MACH_O_N_NO_DEAD_STRIP);
+	break;
+
+      /* Force ld to retain the symbol - even if it appears unused.  */
+      case OBJ_MACH_O_SYM_NO_DEAD_STRIP:
+	s->n_desc |= BFD_MACH_O_N_NO_DEAD_STRIP ;
+	break;
+
+      /* Mach-O's idea of weak ...  */
+      case OBJ_MACH_O_SYM_WEAK_REF:
+	s->n_desc |= BFD_MACH_O_N_WEAK_REF ;
+	break;
+
+      case OBJ_MACH_O_SYM_WEAK_DEF:
+	if (is_defined && sectype != BFD_MACH_O_S_COALESCED)
+	  {
+	    as_bad (_("'%s' can't be a weak_definition (currently only"
+		      " supported in sections of type coalesced)"),
+		      s->symbol.name);
+	    err = 1;
+	  }
+	else
+	  s->n_desc |= BFD_MACH_O_N_WEAK_DEF;
+	break;
+
+      case OBJ_MACH_O_SYM_WEAK:
+        /* A generic 'weak' - we try to figure out what it means at
+	   symbol frob time.  */
+	S_SET_WEAK (sym);
+	break;
+
+      default:
+	break;
+    }
+
+    /* We've seen some kind of qualifier - check validity if or when the entity
+     is defined.  */
+  s->symbol.udata.i = SYM_MACHO_FIELDS_NOT_VALIDATED;
+  return err;
+}
+
+/* Respond to symbol qualifiers.
+   All of the form:
+   .<qualifier> symbol [, symbol]*
+   a list of symbols is an extension over the Darwin system as.  */
+
+static void
+obj_mach_o_sym_qual (int ntype)
+{
+  char *name;
+  char c;
+  symbolS *symbolP;
+
+#ifdef md_flush_pending_output
+  md_flush_pending_output ();
+#endif
+
+  do
+    {
+      name = input_line_pointer;
+      c = get_symbol_end ();
+      symbolP = symbol_find_or_make (name);
+      obj_mach_o_set_symbol_qualifier (symbolP, ntype);
+      *input_line_pointer = c;
+      SKIP_WHITESPACE ();
+      c = *input_line_pointer;
+      if (c == ',')
+	{
+	  input_line_pointer++;
+	  SKIP_WHITESPACE ();
+	  if (is_end_of_line[(unsigned char) *input_line_pointer])
+	    c = '\n';
+	}
+    }
+  while (c == ',');
+
+  demand_empty_rest_of_line ();
+}
+
 /* Dummy function to allow test-code to work while we are working
    on things.  */
 
@@ -1068,11 +1220,18 @@ const pseudo_typeS mach_o_pseudo_table[] =
   { "section", obj_mach_o_section, 0},
   { "zerofill", obj_mach_o_zerofill, 0},
 
-  /* Symbol-related.  */
-  { "indirect_symbol", obj_mach_o_placeholder, 0},
-  { "weak_definition", obj_mach_o_placeholder, 0},
-  { "private_extern", obj_mach_o_placeholder, 0},
-  { "weak", obj_mach_o_weak, 0},   /* extension */
+  /* Symbol qualifiers.  */
+  {"local",		obj_mach_o_sym_qual, OBJ_MACH_O_SYM_LOCAL},
+  {"globl",		obj_mach_o_sym_qual, OBJ_MACH_O_SYM_GLOBL},
+  {"reference",		obj_mach_o_sym_qual, OBJ_MACH_O_SYM_REFERENCE},
+  {"weak_reference",	obj_mach_o_sym_qual, OBJ_MACH_O_SYM_WEAK_REF},
+  {"lazy_reference",	obj_mach_o_sym_qual, OBJ_MACH_O_SYM_LAZY_REF},
+  {"weak_definition",	obj_mach_o_sym_qual, OBJ_MACH_O_SYM_WEAK_DEF},
+  {"private_extern",	obj_mach_o_sym_qual, OBJ_MACH_O_SYM_PRIV_EXT},
+  {"no_dead_strip",	obj_mach_o_sym_qual, OBJ_MACH_O_SYM_NO_DEAD_STRIP},
+  {"weak",		obj_mach_o_sym_qual, OBJ_MACH_O_SYM_WEAK}, /* ext */
+
+  {"indirect_symbol",	obj_mach_o_placeholder, 0},
 
   /* File flags.  */
   { "subsections_via_symbols", obj_mach_o_fileprop, 
@@ -1081,6 +1240,154 @@ const pseudo_typeS mach_o_pseudo_table[] =
   {NULL, NULL, 0}
 };
 
+/* Determine the default n_type value for a symbol from its section.  */
+
+static unsigned
+obj_mach_o_type_for_symbol (bfd_mach_o_asymbol *s)
+{
+  if (s->symbol.section == bfd_abs_section_ptr)
+    return BFD_MACH_O_N_ABS;
+  else if (s->symbol.section == bfd_com_section_ptr
+	   || s->symbol.section == bfd_und_section_ptr)
+    return BFD_MACH_O_N_UNDF;
+  else
+    return BFD_MACH_O_N_SECT;
+}
+
+/* We need to check the correspondence between some kinds of symbols and their
+   sections.  Common and BSS vars will seen via the obj_macho_comm() function.
+   
+   The earlier we can pick up a problem, the better the diagnostics will be.
+   
+   However, when symbol type information is attached, the symbol section will
+   quite possibly be unknown.  So we are stuck with checking (most of the)
+   validity at the time the file is written (unfortunately, then one doesn't
+   get line number information in the diagnostic).  */
+
+/* Here we pick up the case where symbol qualifiers have been applied that
+   are possibly incompatible with the section etc. that the symbol is defined
+   in.  */
+
+void obj_macho_frob_label (struct symbol *sp)
+{
+  bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (sp);
+  /* This is the base symbol type, that we mask in.  */
+  unsigned base_type = obj_mach_o_type_for_symbol (s);
+  bfd_mach_o_section *sec = bfd_mach_o_get_mach_o_section (s->symbol.section);
+  int sectype = -1;
+
+  if ((s->n_type & BFD_MACH_O_N_STAB) != 0)
+    return; /* Leave alone.  */
+  
+  if (sec != NULL)
+    sectype = sec->flags & BFD_MACH_O_SECTION_TYPE_MASK;
+
+  /* If there is a pre-existing qualifier, we can make some checks about
+     validity now.  */
+
+  if(s->symbol.udata.i == SYM_MACHO_FIELDS_NOT_VALIDATED)
+    {
+      if ((s->n_desc & BFD_MACH_O_N_WEAK_DEF)
+	  && sectype != BFD_MACH_O_S_COALESCED)
+	as_bad (_("'%s' can't be a weak_definition (currently only supported"
+		  " in sections of type coalesced)"), s->symbol.name);
+
+      /* Have we changed from an undefined to defined ref? */
+      s->n_desc &= ~(REFE | LAZY);
+    }
+
+  s->n_type &= ~BFD_MACH_O_N_TYPE;
+  s->n_type |= base_type;
+}
+
+/* This is the fall-back, we come here when we get to the end of the file and
+   the symbol is not defined - or there are combinations of qualifiers required
+   (e.g. global + weak_def).  */
+
+int
+obj_macho_frob_symbol (struct symbol *sp)
+{
+  bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (sp);
+  unsigned base_type = obj_mach_o_type_for_symbol (s);
+  bfd_mach_o_section *sec = bfd_mach_o_get_mach_o_section (s->symbol.section);
+  int sectype = -1;
+  
+  if (sec != NULL)
+    sectype = sec->flags & BFD_MACH_O_SECTION_TYPE_MASK;
+
+  if ((s->n_type & BFD_MACH_O_N_STAB) != 0)
+    return 0; /* Leave alone.  */
+  else if (s->symbol.section == bfd_und_section_ptr)
+    {
+      /* ??? Do we really gain much from implementing this as well as the
+	 mach-o specific ones?  */
+      if (s->symbol.flags & BSF_WEAK)
+	s->n_desc |= BFD_MACH_O_N_WEAK_REF;
+
+      /* Undefined references, become extern.  */
+      if (s->n_desc & REFE)
+	{
+	  s->n_desc &= ~REFE;
+	  s->n_type |= BFD_MACH_O_N_EXT;
+	}
+
+      /* So do undefined 'no_dead_strip's.  */
+      if (s->n_desc & BFD_MACH_O_N_NO_DEAD_STRIP)
+	s->n_type |= BFD_MACH_O_N_EXT;
+
+    }
+  else
+    {
+      if ((s->symbol.flags & BSF_WEAK)
+	   && (sectype == BFD_MACH_O_S_COALESCED)
+	   && (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT)))
+	s->n_desc |= BFD_MACH_O_N_WEAK_DEF;
+/* ??? we should do this - but then that reveals that the semantics of weak
+       are different from what's supported in mach-o object files.
+      else
+	as_bad (_("'%s' can't be a weak_definition."),
+		s->symbol.name); */
+    }
+
+  if (s->symbol.udata.i == SYM_MACHO_FIELDS_UNSET)
+    {
+      /* Anything here that should be added that is non-standard.  */
+      s->n_desc &= ~BFD_MACH_O_REFERENCE_MASK;
+    }    
+  else if (s->symbol.udata.i == SYM_MACHO_FIELDS_NOT_VALIDATED)
+    {
+      /* Try to validate any combinations.  */
+      if (s->n_desc & BFD_MACH_O_N_WEAK_DEF)
+	{
+	  if (s->symbol.section == bfd_und_section_ptr)
+	    as_bad (_("'%s' can't be a weak_definition (since it is"
+		      " undefined)"), s->symbol.name);
+	  else if (sectype != BFD_MACH_O_S_COALESCED)
+	    as_bad (_("'%s' can't be a weak_definition (currently only supported"
+		      " in sections of type coalesced)"), s->symbol.name);
+	  else if (! (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT)))
+	    as_bad (_("Non-global symbol: '%s' can't be a weak_definition."),
+		    s->symbol.name);
+	}
+
+    }
+  else
+    as_bad (_("internal error: [%s] unexpected code [%lx] in frob symbol"),
+	    s->symbol.name, (unsigned long)s->symbol.udata.i);
+
+  s->n_type &= ~BFD_MACH_O_N_TYPE;
+  s->n_type |= base_type;
+
+  if (s->symbol.flags & BSF_GLOBAL)
+    s->n_type |= BFD_MACH_O_N_EXT;
+
+  /* This cuts both ways - we promote some things to external above.  */
+  if (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT))
+    S_SET_EXTERNAL (sp);
+
+  return 0;
+}
+
 /* Support stabs for mach-o.  */
 
 void
diff --git a/gas/config/obj-macho.h b/gas/config/obj-macho.h
index b2acd17..cbc3a4f 100644
--- a/gas/config/obj-macho.h
+++ b/gas/config/obj-macho.h
@@ -40,8 +40,8 @@ extern void mach_o_begin (void);
 /* Common symbols can carry alignment information.  */
 #ifndef S_SET_ALIGN
 #define S_SET_ALIGN(S,V) do {\
-  bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (S);\
-  s->n_desc = (s->n_desc & 0xf0ff) | (((V) & 0x0f) << 8);\
+  bfd_mach_o_asymbol *___s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (S);\
+  ___s->n_desc = (___s->n_desc & 0xf0ff) | (((V) & 0x0f) << 8);\
 } while (0)
 #endif
 
@@ -56,6 +56,12 @@ extern const pseudo_typeS mach_o_pseudo_table[];
 #define obj_read_begin_hook()	{;}
 #define obj_symbol_new_hook(s)	{;}
 
+#define obj_frob_label(s) obj_macho_frob_label(s)
+extern void obj_macho_frob_label (struct symbol *);
+
+#define obj_frob_symbol(s, punt) punt = obj_macho_frob_symbol(s)
+extern int obj_macho_frob_symbol (struct symbol *);
+
 #define EMIT_SECTION_SYMBOLS		0
 
 #define OBJ_PROCESS_STAB(SEG,W,S,T,O,D)	obj_mach_o_process_stab(W,S,T,O,D)
diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index c638cdc..3176c0c 100644
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,3 +1,15 @@
+2012-01-09  Iain Sandoe  <idsandoe@googlemail.com>
+
+	* gas/mach-o/err-syms-1.s: New.
+	* gas/mach-o/err-syms-2.s: New.
+	* gas/mach-o/err-syms-3.s: New.
+	* gas/mach-o/symbols-2.d: New.
+	* gas/mach-o/symbols-2.s: New.
+	* gas/mach-o/symbols-3.s: New.
+	* gas/mach-o/symbols-4.s: New.
+	* gas/mach-o/symbols-5.d: New.
+	* gas/mach-o/symbols-5.s: New.
+
 2012-01-08  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	* gas/mips/tls-relw.s, gas/mips/tls-relw.d: New test.
diff --git a/gas/testsuite/gas/mach-o/err-syms-1.s b/gas/testsuite/gas/mach-o/err-syms-1.s
new file mode 100644
index 0000000..84146c7
--- /dev/null
+++ b/gas/testsuite/gas/mach-o/err-syms-1.s
@@ -0,0 +1,12 @@
+# { dg-do assemble }
+
+	.globl a
+a:	.space 1
+	.local a
+
+	.private_extern b
+b:	.space 1
+	.local b
+
+# { dg-error ".a. previously declared as .global." "" { target *-*-darwin*} 5 }
+# { dg-error ".b. previously declared as .private extern." "" { target *-*-darwin*} 9 }
diff --git a/gas/testsuite/gas/mach-o/err-syms-2.s b/gas/testsuite/gas/mach-o/err-syms-2.s
new file mode 100644
index 0000000..ad4a692
--- /dev/null
+++ b/gas/testsuite/gas/mach-o/err-syms-2.s
@@ -0,0 +1,15 @@
+# { dg-do assemble }
+
+	.section __weak, __weak, coalesced
+
+a:	.space 1
+	.weak_definition a
+
+	.weak_definition b
+b:	.space 1
+	
+	.weak_definition c
+
+# { dg-error "Non-global symbol: .a. can.t be a weak_definition." "" { target *-*-darwin*} 0 }
+# { dg-error "Non-global symbol: .b. can.t be a weak_definition." "" { target *-*-darwin*} 0 }
+# { dg-error ".c. can.t be a weak_definition .since it is undefined." "" { target *-*-darwin*} 0 }
diff --git a/gas/testsuite/gas/mach-o/err-syms-3.s b/gas/testsuite/gas/mach-o/err-syms-3.s
new file mode 100644
index 0000000..8315d86
--- /dev/null
+++ b/gas/testsuite/gas/mach-o/err-syms-3.s
@@ -0,0 +1,10 @@
+# { dg-do assemble }
+
+	.weak_definition a
+a:	.space 1
+
+b:	.space 1
+	.weak_definition b
+
+# { dg-error ".a. can.t be a weak_definition .currently only supported in sections of type coalesced." "" { target *-*-darwin*} 4 }
+# { dg-error ".b. can.t be a weak_definition .currently only supported in sections of type coalesced." "" { target *-*-darwin*} 7 }
diff --git a/gas/testsuite/gas/mach-o/symbols-2.d b/gas/testsuite/gas/mach-o/symbols-2.d
new file mode 100644
index 0000000..c4bfcbd
--- /dev/null
+++ b/gas/testsuite/gas/mach-o/symbols-2.d
@@ -0,0 +1,7 @@
+#objdump: -t
+# weak_definitions.
+.*: +file format mach-o.*
+#...
+SYMBOL TABLE:
+(00000000)?00000000 g.*1f SECT.*02 0080 \[__weak.__weak\] a
+(00000000)?00000001 g.*0f SECT.*02 0080 \[__weak.__weak\] b
diff --git a/gas/testsuite/gas/mach-o/symbols-2.s b/gas/testsuite/gas/mach-o/symbols-2.s
new file mode 100644
index 0000000..2ba36d1
--- /dev/null
+++ b/gas/testsuite/gas/mach-o/symbols-2.s
@@ -0,0 +1,9 @@
+	.section __weak, __weak, coalesced
+
+	.private_extern a
+	.weak_definition a
+a:	.space 1
+
+	.globl b
+	.weak_definition b
+b:	.space 1
diff --git a/gas/testsuite/gas/mach-o/symbols-3.s b/gas/testsuite/gas/mach-o/symbols-3.s
new file mode 100644
index 0000000..054fdf6
--- /dev/null
+++ b/gas/testsuite/gas/mach-o/symbols-3.s
@@ -0,0 +1,111 @@
+# indirect references, stubs and {non,}_lazy_symbol_pointer sections.
+# not applicable to x86_64 mach-o.
+
+	.text
+	.globl c
+	.globl c1
+	.globl c2
+c:	nop
+c1:	nop
+c2:	nop
+
+e:	nop
+e1:	nop
+e2:	nop
+
+	.data
+d:	.space 8
+d1:	.space 8
+d2:	.space 8
+
+	.private_extern f
+	.private_extern f1
+	.private_extern f2
+f:	.space 8
+f1:	.space 8
+f2:	.space 8
+
+	.section __dummy, __dummy, symbol_stubs,strip_static_syms,8
+
+	.indirect_symbol a
+La:	.space 8
+
+	.indirect_symbol b
+Lb:	.space 8
+
+	.indirect_symbol c
+Lc:	.space 8
+
+	.indirect_symbol d
+Ld:	.space 8
+
+	.indirect_symbol e
+Le:	.space 8
+
+	.indirect_symbol f
+Lf:	.space 8
+
+	.private_extern g
+	.indirect_symbol g
+Lg:	.space 8
+
+	.lazy_symbol_pointer
+
+	.indirect_symbol a1
+La1:	.space 4
+
+	.indirect_symbol b1
+Lb1:	.space 4
+
+	.indirect_symbol c1
+Lc1:	.space 4
+
+	.indirect_symbol d1
+Ld1:	.space 4
+
+	.indirect_symbol e1
+Le1:	.space 4
+
+	.indirect_symbol f1
+Lf1:	.space 4
+
+	.private_extern g1
+	.indirect_symbol g1
+Lg1:	.space 4
+
+	.non_lazy_symbol_pointer
+
+	.indirect_symbol a2
+La2:	.space 4
+
+	.indirect_symbol b2
+Lb2:	.space 4
+
+	.indirect_symbol c2
+Lc2:	.space 4
+
+	.indirect_symbol d2
+Ld2:	.space 4
+
+	.indirect_symbol e2
+Le2:	.space 4
+
+	.indirect_symbol f2
+Lf2:	.space 4
+
+	.private_extern g2
+	.indirect_symbol g2
+Lg2:	.space 4
+
+	.indirect_symbol f1
+Lf11:	.space 4
+
+	.private_extern g1
+	.indirect_symbol g1
+Lg11:	.space 4
+
+	.indirect_symbol a2
+La12:	.space 4
+
+	.indirect_symbol b2
+Lb12:	.space 4
diff --git a/gas/testsuite/gas/mach-o/symbols-4.s b/gas/testsuite/gas/mach-o/symbols-4.s
new file mode 100644
index 0000000..8800806
--- /dev/null
+++ b/gas/testsuite/gas/mach-o/symbols-4.s
@@ -0,0 +1,65 @@
+# Reference & dead strip permutations.
+
+	.text
+	
+	.reference ua
+	.lazy_reference ub
+	
+	.reference ua1
+	.private_extern ua1
+
+	.private_extern ub1
+	.lazy_reference ub1
+	
+c:	.space 1
+	.reference c
+
+d:	.space 1
+	.lazy_reference d
+
+	.reference c1
+c1:	.space 1
+
+	.lazy_reference d1
+d1:	.space 1
+
+	.private_extern e
+	.reference e
+	
+	.private_extern f
+	.lazy_reference f
+
+g:	.space 1
+	.private_extern g
+	.reference g
+
+h:	.space 1
+	.private_extern h
+	.lazy_reference h
+
+	.private_extern g1
+	.reference g1
+g1:	.space 1
+
+	.private_extern h1
+	.lazy_reference h1
+h1:	.space 1
+
+	.no_dead_strip n
+	
+	.globl m
+	.no_dead_strip m
+
+	.private_extern p
+	.no_dead_strip p
+
+n1:	.space 1
+	.no_dead_strip n1
+	
+m1:	.space 1
+	.globl m1
+	.no_dead_strip m1
+
+p1:	.space 1
+	.private_extern p1
+	.no_dead_strip p1
diff --git a/gas/testsuite/gas/mach-o/symbols-5.d b/gas/testsuite/gas/mach-o/symbols-5.d
new file mode 100644
index 0000000..7f87e74
--- /dev/null
+++ b/gas/testsuite/gas/mach-o/symbols-5.d
@@ -0,0 +1,11 @@
+#objdump: -t
+# globals and private_externs
+.*: +file format mach-o.*
+#...
+SYMBOL TABLE:
+(00000000)?00000000 g.*1f SECT.*01 0000 \[.text\] a
+(00000000)?00000001 g.*0f SECT.*01 0000 \[.text\] b
+(00000000)?00000002 g.*1f SECT.*01 0000 \[.text\] c
+(00000000)?00000000 g.*11 UND.*00 0000 d
+(00000000)?00000000 g.*01 UND.*00 0000 e
+(00000000)?00000000 g.*11 UND.*00 0000 f
diff --git a/gas/testsuite/gas/mach-o/symbols-5.s b/gas/testsuite/gas/mach-o/symbols-5.s
new file mode 100644
index 0000000..a43266d
--- /dev/null
+++ b/gas/testsuite/gas/mach-o/symbols-5.s
@@ -0,0 +1,17 @@
+
+	.private_extern a
+a:	.space 1
+
+	.globl b
+b:	.space 1
+
+	.private_extern c
+	.globl c
+c:	.space 1
+
+	.private_extern d
+	
+	.globl e
+	
+	.globl f
+	.private_extern f