Duplicate output sections in scripts

Previously, ld merged duplicate output sections if such existed in
scripts, except for those with a constraint of SPECIAL.  This makes
scripts with duplicate output section statements create duplicate
output sections in the linker output file.

	* ldlang.c (lang_output_section_statement_lookup): Change "create"
	parameter to a tristate, if 2 then always create a new output
	section statement.  Update all callers, with
	lang_enter_output_section_statement using "2".
	(map_input_to_output_sections): Don't ignore SPECIAL constraint
	here.
	* ldlang.h (lang_output_section_statement_type): Update prototype.
	(lang_output_section_find): Update.

3 files changed, 45 insertions, 42 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 0faa03a..d7280ef 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,14 @@
+2020-11-25  Alan Modra  <amodra@gmail.com>
+
+	* ldlang.c (lang_output_section_statement_lookup): Change "create"
+	parameter to a tristate, if 2 then always create a new output
+	section statement.  Update all callers, with
+	lang_enter_output_section_statement using "2".
+	(map_input_to_output_sections): Don't ignore SPECIAL constraint
+	here.
+	* ldlang.h (lang_output_section_statement_type): Update prototype.
+	(lang_output_section_find): Update.
+
 2020-11-24  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR gold/26939
diff --git a/ld/ldlang.c b/ld/ldlang.c
index b70937a..41000da 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -1305,7 +1305,7 @@ lang_init (void)
   first_file = lang_add_input_file (NULL, lang_input_file_is_marker_enum,
 				    NULL);
   abs_output_section =
-    lang_output_section_statement_lookup (BFD_ABS_SECTION_NAME, 0, TRUE);
+    lang_output_section_statement_lookup (BFD_ABS_SECTION_NAME, 0, 1);
 
   abs_output_section->bfd_section = bfd_abs_section_ptr;
 
@@ -1464,19 +1464,21 @@ lang_output_section_get (const asection *output_section)
 
 /* Find or create an output_section_statement with the given NAME.
    If CONSTRAINT is non-zero match one with that constraint, otherwise
-   match any non-negative constraint.  If CREATE, always make a
-   new output_section_statement for SPECIAL CONSTRAINT.  */
+   match any non-negative constraint.  If CREATE is 0 return NULL when
+   no match exists.  If CREATE is 1, create an output_section_statement
+   when no match exists or if CONSTRAINT is SPECIAL.  If CREATE is 2,
+   always make a new output_section_statement.  */
 
 lang_output_section_statement_type *
 lang_output_section_statement_lookup (const char *name,
 				      int constraint,
-				      bfd_boolean create)
+				      int create)
 {
   struct out_section_hash_entry *entry;
 
   entry = ((struct out_section_hash_entry *)
 	   bfd_hash_lookup (&output_section_statement_table, name,
-			    create, FALSE));
+			    create != 0, FALSE));
   if (entry == NULL)
     {
       if (create)
@@ -1491,23 +1493,19 @@ lang_output_section_statement_lookup (const char *name,
       struct out_section_hash_entry *last_ent;
 
       name = entry->s.output_section_statement.name;
-      if (create && constraint == SPECIAL)
-	/* Not traversing to the end reverses the order of the second
-	   and subsequent SPECIAL sections in the hash table chain,
-	   but that shouldn't matter.  */
-	last_ent = entry;
-      else
-	do
-	  {
-	    if (constraint == entry->s.output_section_statement.constraint
-		|| (constraint == 0
-		    && entry->s.output_section_statement.constraint >= 0))
-	      return &entry->s.output_section_statement;
-	    last_ent = entry;
-	    entry = (struct out_section_hash_entry *) entry->root.next;
-	  }
-	while (entry != NULL
-	       && name == entry->s.output_section_statement.name);
+      do
+	{
+	  if (create != 2
+	      && !(create && constraint == SPECIAL)
+	      && (constraint == entry->s.output_section_statement.constraint
+		  || (constraint == 0
+		      && entry->s.output_section_statement.constraint >= 0)))
+	    return &entry->s.output_section_statement;
+	  last_ent = entry;
+	  entry = (struct out_section_hash_entry *) entry->root.next;
+	}
+      while (entry != NULL
+	     && name == entry->s.output_section_statement.name);
 
       if (!create)
 	return NULL;
@@ -4175,22 +4173,18 @@ map_input_to_output_sections
 	  break;
 	case lang_output_section_statement_enum:
 	  tos = &s->output_section_statement;
-	  if (tos->constraint != 0)
+	  if (tos->constraint == ONLY_IF_RW
+	      || tos->constraint == ONLY_IF_RO)
 	    {
-	      if (tos->constraint != ONLY_IF_RW
-		  && tos->constraint != ONLY_IF_RO)
-		break;
 	      tos->all_input_readonly = TRUE;
 	      check_input_sections (tos->children.head, tos);
 	      if (tos->all_input_readonly != (tos->constraint == ONLY_IF_RO))
-		{
-		  tos->constraint = -1;
-		  break;
-		}
+		tos->constraint = -1;
 	    }
-	  map_input_to_output_sections (tos->children.head,
-					target,
-					tos);
+	  if (tos->constraint >= 0)
+	    map_input_to_output_sections (tos->children.head,
+					  target,
+					  tos);
 	  break;
 	case lang_output_statement_enum:
 	  break;
@@ -4270,7 +4264,7 @@ map_input_to_output_sections
 		 place them in amongst other sections then the address
 		 will affect following script sections, which is
 		 likely to surprise naive users.  */
-	      tos = lang_output_section_statement_lookup (name, 0, TRUE);
+	      tos = lang_output_section_statement_lookup (name, 0, 1);
 	      tos->addr_tree = s->address_statement.address;
 	      if (tos->bfd_section == NULL)
 		init_os (tos, 0);
@@ -7206,8 +7200,7 @@ ldlang_place_orphan (asection *s)
   if (config.orphan_handling == orphan_handling_discard)
     {
       lang_output_section_statement_type *os;
-      os = lang_output_section_statement_lookup (DISCARD_SECTION_NAME, 0,
-						 TRUE);
+      os = lang_output_section_statement_lookup (DISCARD_SECTION_NAME, 0, 1);
       if (os->addr_tree == NULL
 	  && (bfd_link_relocatable (&link_info)
 	      || (s->flags & (SEC_LOAD | SEC_ALLOC)) == 0))
@@ -7230,7 +7223,7 @@ ldlang_place_orphan (asection *s)
       os = ldemul_place_orphan (s, name, constraint);
       if (os == NULL)
 	{
-	  os = lang_output_section_statement_lookup (name, constraint, TRUE);
+	  os = lang_output_section_statement_lookup (name, constraint, 1);
 	  if (os->addr_tree == NULL
 	      && (bfd_link_relocatable (&link_info)
 		  || (s->flags & (SEC_LOAD | SEC_ALLOC)) == 0))
@@ -7277,8 +7270,7 @@ lang_place_orphans (void)
 		    {
 		      if (default_common_section == NULL)
 			default_common_section
-			  = lang_output_section_statement_lookup (".bss", 0,
-								  TRUE);
+			  = lang_output_section_statement_lookup (".bss", 0, 1);
 		      lang_add_section (&default_common_section->children, s,
 					NULL, default_common_section);
 		    }
@@ -7420,7 +7412,7 @@ lang_enter_output_section_statement (const char *output_section_statement_name,
   lang_output_section_statement_type *os;
 
   os = lang_output_section_statement_lookup (output_section_statement_name,
-					     constraint, TRUE);
+					     constraint, 2);
   current_section = os;
 
   if (os->addr_tree == NULL)
diff --git a/ld/ldlang.h b/ld/ldlang.h
index 6675c57..0f1b607 100644
--- a/ld/ldlang.h
+++ b/ld/ldlang.h
@@ -586,7 +586,7 @@ extern asection *section_for_dot
        statement = statement->next)
 
 #define lang_output_section_find(NAME) \
-  lang_output_section_statement_lookup (NAME, 0, FALSE)
+  lang_output_section_statement_lookup (NAME, 0, 0)
 
 extern void lang_process
   (void);
@@ -605,7 +605,7 @@ extern void lang_add_keepsyms_file
 extern lang_output_section_statement_type *lang_output_section_get
   (const asection *);
 extern lang_output_section_statement_type *lang_output_section_statement_lookup
-  (const char *, int, bfd_boolean);
+  (const char *, int, int);
 extern lang_output_section_statement_type *next_matching_output_section_statement
   (lang_output_section_statement_type *, int);
 extern void ldlang_add_undef