--- a/gcc/dwarf2asm.c	Thu Oct 25 08:08:40 2018 +0900
+++ b/gcc/dwarf2asm.c	Thu Oct 25 10:21:07 2018 +0900
@@ -1,5 +1,5 @@
 /* Dwarf2 assembler output helper routines.
-   Copyright (C) 2001-2017 Free Software Foundation, Inc.
+   Copyright (C) 2001-2018 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -33,6 +33,7 @@
 #include "dwarf2.h"
 #include "function.h"
 #include "emit-rtl.h"
+#include "fold-const.h"
 
 #ifndef XCOFF_DEBUGGING_INFO
 #define XCOFF_DEBUGGING_INFO 0
@@ -767,6 +768,35 @@
   va_end (ap);
 }
 
+/* Output symbol LAB1 as an unsigned LEB128 quantity.  LAB1 should be
+   an assembler-computed constant, e.g. a view number, because we
+   can't have relocations in LEB128 quantities.  */
+
+void
+dw2_asm_output_symname_uleb128 (const char *lab1 ATTRIBUTE_UNUSED,
+				const char *comment, ...)
+{
+  va_list ap;
+
+  va_start (ap, comment);
+
+#ifdef HAVE_AS_LEB128
+  fputs ("\t.uleb128 ", asm_out_file);
+  assemble_name (asm_out_file, lab1);
+#else
+  gcc_unreachable ();
+#endif
+
+  if (flag_debug_asm && comment)
+    {
+      fprintf (asm_out_file, "\t%s ", ASM_COMMENT_START);
+      vfprintf (asm_out_file, comment, ap);
+    }
+  fputc ('\n', asm_out_file);
+
+  va_end (ap);
+}
+
 void
 dw2_asm_output_delta_uleb128 (const char *lab1 ATTRIBUTE_UNUSED,
 			      const char *lab2 ATTRIBUTE_UNUSED,
@@ -781,7 +811,17 @@
   fputs ("\t.uleb128 ", asm_out_file);
   assemble_name (asm_out_file, lab1);
   putc ('-', asm_out_file);
-  assemble_name (asm_out_file, lab2);
+  /* dwarf2out.c might give us a label expression (e.g. .LVL548-1)
+     as second argument.  If so, make it a subexpression, to make
+     sure the substraction is done in the right order.  */
+  if (strchr (lab2, '-') != NULL)
+    {
+      putc ('(', asm_out_file);
+      assemble_name (asm_out_file, lab2);
+      putc (')', asm_out_file);
+    }
+  else
+    assemble_name (asm_out_file, lab2);
 
   if (flag_debug_asm && comment)
     {
@@ -925,7 +965,7 @@
   SET_DECL_ASSEMBLER_NAME (decl, id);
   DECL_ARTIFICIAL (decl) = 1;
   DECL_IGNORED_P (decl) = 1;
-  DECL_INITIAL (decl) = decl;
+  DECL_INITIAL (decl) = build_fold_addr_expr (decl);
   TREE_READONLY (decl) = 1;
   TREE_STATIC (decl) = 1;
 
@@ -938,8 +978,23 @@
     }
 
   sym_ref = gen_rtx_SYMBOL_REF (Pmode, sym);
+  /* Disable ASan for decl because redzones cause ABI breakage between GCC and
+     libstdc++ for `.LDFCM*' variables.  See PR 78651 for details.  */
+  unsigned int save_flag_sanitize = flag_sanitize;
+  flag_sanitize &= ~(SANITIZE_ADDRESS | SANITIZE_USER_ADDRESS
+		     | SANITIZE_KERNEL_ADDRESS);
+  /* And also temporarily disable -fsection-anchors.  These indirect constants
+     are never referenced from code, so it doesn't make any sense to aggregate
+     them in blocks.  */
+  int save_flag_section_anchors = flag_section_anchors;
+  flag_section_anchors = 0;
   assemble_variable (decl, 1, 1, 1);
+  flag_section_anchors = save_flag_section_anchors;
+  flag_sanitize = save_flag_sanitize;
   assemble_integer (sym_ref, POINTER_SIZE_UNITS, POINTER_SIZE, 1);
+  /* The following is a hack recognized by use_blocks_for_decl_p to disable
+     section anchor handling of the decl.  */
+  DECL_INITIAL (decl) = decl;
 
   return 0;
 }