PR24008, Wrong value of ternary expression in map file

Message ID 20190128012003.GN29797@bubble.grove.modra.org
State New
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Series
  • PR24008, Wrong value of ternary expression in map file
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Commit Message

Alan Modra Jan. 28, 2019, 1:20 a.m.
Printing in map files had the result of expressions involving DEFINED
wrong due to the definedness_table not being updated in that pass over
the script.  Fixed by passing the entire assignment expression to
exp_fold_tree and taking care that the map file pass doesn't twiddle
symbol values further.

	PR 24008
	* ldexp.h (lang_phase_type): Add lang_fixed_phase_enum.
	* ldexp.c (fold_name): Move expld.assign_name check later to
	avoid an extra lookup.
	(exp_fold_tree_1): When lang_fixed_phase_enum, don't change symbol
	values, and don't clear expld.assign_name.
	* ldlang.c (lang_map): Set expld.phase to lang_fixed_phase_enum.
	(print_assignment): Resolve entire assignment expression.
	Don't access symbol u.def unless symbol is defined.


-- 
Alan Modra
Australia Development Lab, IBM

Patch

diff --git a/ld/ldexp.c b/ld/ldexp.c
index a8b833a6bb..60b17ef576 100644
--- a/ld/ldexp.c
+++ b/ld/ldexp.c
@@ -720,23 +720,6 @@  fold_name (etree_type *tree)
       break;
 
     case NAME:
-      if (expld.assign_name != NULL
-	  && strcmp (expld.assign_name, tree->name.name) == 0)
-	{
-	  /* Self-assignment is only allowed for absolute symbols
-	     defined in a linker script.  */
-	  h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
-					    &link_info,
-					    tree->name.name,
-					    FALSE, FALSE, TRUE);
-	  if (!(h != NULL
-		&& (h->type == bfd_link_hash_defined
-		    || h->type == bfd_link_hash_defweak)
-		&& h->u.def.section == bfd_abs_section_ptr
-		&& (def = symbol_defined (tree->name.name)) != NULL
-		&& def->iteration == (lang_statement_iteration & 255)))
-	    expld.assign_name = NULL;
-	}
       if (tree->name.name[0] == '.' && tree->name.name[1] == 0)
 	new_rel_from_abs (expld.dot);
       else
@@ -787,6 +770,18 @@  fold_name (etree_type *tree)
 	    expld.assign_src = h;
 	  else
 	    expld.assign_src = (struct bfd_link_hash_entry *) - 1;
+
+	  /* Self-assignment is only allowed for absolute symbols
+	     defined in a linker script.  */
+	  if (expld.assign_name != NULL
+	      && strcmp (expld.assign_name, tree->name.name) == 0
+	      && !(h != NULL
+		   && (h->type == bfd_link_hash_defined
+		       || h->type == bfd_link_hash_defweak)
+		   && h->u.def.section == bfd_abs_section_ptr
+		   && (def = symbol_defined (tree->name.name)) != NULL
+		   && def->iteration == (lang_statement_iteration & 255)))
+	    expld.assign_name = NULL;
 	}
       break;
 
@@ -1158,7 +1153,8 @@  exp_fold_tree_1 (etree_type *tree)
 	     converted to absolute values, as is required by many
 	     expressions, until final section sizing is complete.  */
 	  if (expld.phase == lang_final_phase_enum
-              || expld.assign_name != NULL)
+	      || expld.phase == lang_fixed_phase_enum
+	      || expld.assign_name != NULL)
 	    {
 	      if (tree->type.node_class == etree_provide)
 		tree->type.node_class = etree_provided;
@@ -1199,28 +1195,40 @@  exp_fold_tree_1 (etree_type *tree)
 			(&link_info, h, link_info.output_bfd,
 			 expld.result.section, expld.result.value);
 		    }
-		  h->type = bfd_link_hash_defined;
-		  h->u.def.value = expld.result.value;
-		  h->u.def.section = expld.result.section;
-		  h->linker_def = ! tree->assign.type.lineno;
-		  h->ldscript_def = 1;
-		  h->rel_from_abs = expld.rel_from_abs;
-		  if (tree->assign.hidden)
-		    bfd_link_hide_symbol (link_info.output_bfd,
-					  &link_info, h);
-
-		  /* Copy the symbol type if this is an expression only
-		     referencing a single symbol.  (If the expression
-		     contains ternary conditions, ignoring symbols on
-		     false branches.)  */
-		  if (expld.assign_src != NULL
-		      && (expld.assign_src
-			  != (struct bfd_link_hash_entry *) -1))
-		    bfd_copy_link_hash_symbol_type (link_info.output_bfd, h,
-						    expld.assign_src);
+		  if (expld.phase == lang_fixed_phase_enum)
+		    {
+		      if (h->type == bfd_link_hash_defined)
+			{
+			  expld.result.value = h->u.def.value;
+			  expld.result.section = h->u.def.section;
+			}
+		    }
+		  else
+		    {
+		      h->type = bfd_link_hash_defined;
+		      h->u.def.value = expld.result.value;
+		      h->u.def.section = expld.result.section;
+		      h->linker_def = ! tree->assign.type.lineno;
+		      h->ldscript_def = 1;
+		      h->rel_from_abs = expld.rel_from_abs;
+		      if (tree->assign.hidden)
+			bfd_link_hide_symbol (link_info.output_bfd,
+					      &link_info, h);
+
+		      /* Copy the symbol type if this is an expression only
+			 referencing a single symbol.  (If the expression
+			 contains ternary conditions, ignoring symbols on
+			 false branches.)  */
+		      if (expld.assign_src != NULL
+			  && (expld.assign_src
+			      != (struct bfd_link_hash_entry *) -1))
+			bfd_copy_link_hash_symbol_type (link_info.output_bfd,
+							h, expld.assign_src);
+		    }
 		}
 	    }
-	  expld.assign_name = NULL;
+	  if (expld.phase != lang_fixed_phase_enum)
+	    expld.assign_name = NULL;
 	}
       break;
 
diff --git a/ld/ldexp.h b/ld/ldexp.h
index 8dc1bf941f..71395bc6c4 100644
--- a/ld/ldexp.h
+++ b/ld/ldexp.h
@@ -106,7 +106,9 @@  typedef enum
   /* During assignment of symbol values when relaxation in progress.  */
   lang_assigning_phase_enum,
   /* Final assignment of symbol values.  */
-  lang_final_phase_enum
+  lang_final_phase_enum,
+  /* Run after symbol values have been fixed, for lang_map.  */
+  lang_fixed_phase_enum
 } lang_phase_type;
 
 union lang_statement_union;
diff --git a/ld/ldlang.c b/ld/ldlang.c
index bddce6d81a..33f6bda292 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -2315,6 +2315,7 @@  lang_map (void)
       obstack_begin (&map_obstack, 1000);
       bfd_link_hash_traverse (link_info.hash, sort_def_symbol, 0);
     }
+  expld.phase = lang_fixed_phase_enum;
   lang_statement_iteration++;
   print_statements ();
 
@@ -4244,9 +4245,7 @@  print_assignment (lang_assignment_statement_type *assignment,
       const char *dst = assignment->exp->assign.dst;
 
       is_dot = (dst[0] == '.' && dst[1] == 0);
-      if (!is_dot)
-	expld.assign_name = dst;
-      tree = assignment->exp->assign.src;
+      tree = assignment->exp;
     }
 
   osec = output_section->bfd_section;
@@ -4281,7 +4280,9 @@  print_assignment (lang_assignment_statement_type *assignment,
 
 	  h = bfd_link_hash_lookup (link_info.hash, assignment->exp->assign.dst,
 				    FALSE, FALSE, TRUE);
-	  if (h)
+	  if (h != NULL
+	      && (h->type == bfd_link_hash_defined
+		  || h->type == bfd_link_hash_defweak))
 	    {
 	      value = h->u.def.value;
 	      value += h->u.def.section->output_section->vma;