Improve ODR checking in gold.

gold/
	* debug.h (DEBUG_LOCATION): New.
	(DEBUG_ALL): Include DEBUG_LOCATION.
	(debug_string_to_enum): Add DEBUG_LOCATION.
	* dwarf_reader.cc (Sized_dwarf_line_info::read_lines): Fix debug
	output to print correct context.
	(Sized_dwarf_line_info::do_addr2line): Add debug output. Return
	up to 4 more locations at the beginning of the function.
	* symtab.cc (Symbol_table::detect_odr_violations): Get canonical
	result before sorting list of line numbers.
	* testsuite/debug_msg.sh: Allow range of line numbers for
	canonical results on optimized code.

1 files changed, 26 insertions, 6 deletions

diff --git a/gold/dwarf_reader.cc b/gold/dwarf_reader.cc
index e7c95ce..59b85b8 100644
--- a/gold/dwarf_reader.cc
+++ b/gold/dwarf_reader.cc
@@ -2205,13 +2205,33 @@ Sized_dwarf_line_info<size, big_endian>::do_addr2line(
     return "";
 
   std::string result = this->format_file_lineno(*it);
+  gold_debug(DEBUG_LOCATION, "do_addr2line: canonical result: %s",
+	     result.c_str());
   if (other_lines != NULL)
-    for (++it; it != offsets->end() && it->offset == offset; ++it)
-      {
-        if (it->line_num == -1)
-          continue;  // The end of a previous function.
-        other_lines->push_back(this->format_file_lineno(*it));
-      }
+    {
+      unsigned int last_file_num = it->file_num;
+      int last_line_num = it->line_num;
+      // Return up to 4 more locations from the beginning of the function
+      // for fuzzy matching.
+      for (++it; it != offsets->end(); ++it)
+	{
+	  if (it->offset == offset && it->line_num == -1)
+	    continue;  // The end of a previous function.
+	  if (it->line_num == -1)
+	    break;  // The end of the current function.
+	  if (it->file_num != last_file_num || it->line_num != last_line_num)
+	    {
+	      other_lines->push_back(this->format_file_lineno(*it));
+	      gold_debug(DEBUG_LOCATION, "do_addr2line: other: %s",
+			 other_lines->back().c_str());
+	      last_file_num = it->file_num;
+	      last_line_num = it->line_num;
+	    }
+	  if (it->offset > offset && other_lines->size() >= 4)
+	    break;
+	}
+    }
+
   return result;
 }