--- a/gcc/fortran/primary.c	Fri Oct 27 22:46:09 2017 +0900
+++ b/gcc/fortran/primary.c	Thu Oct 25 07:37:49 2018 +0900
@@ -1,5 +1,5 @@
 /* Primary expression subroutines
-   Copyright (C) 2000-2017 Free Software Foundation, Inc.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
    Contributed by Andy Vaught
 
 This file is part of GCC.
@@ -862,7 +862,7 @@
 
       ref->type = REF_SUBSTRING;
       if (start == NULL)
-	start = gfc_get_int_expr (gfc_default_integer_kind, NULL, 1);
+	start = gfc_get_int_expr (gfc_charlen_int_kind, NULL, 1);
       ref->u.ss.start = start;
       if (end == NULL && cl)
 	end = gfc_copy_expr (cl->length);
@@ -1006,7 +1006,8 @@
 match_string_constant (gfc_expr **result)
 {
   char name[GFC_MAX_SYMBOL_LEN + 1], peek;
-  int i, kind, length, save_warn_ampersand, ret;
+  size_t length;
+  int kind,save_warn_ampersand, ret;
   locus old_locus, start_locus;
   gfc_symbol *sym;
   gfc_expr *e;
@@ -1125,7 +1126,7 @@
   warn_ampersand = false;
 
   p = e->value.character.string;
-  for (i = 0; i < length; i++)
+  for (size_t i = 0; i < length; i++)
     {
       c = next_string_char (delimiter, &ret);
 
@@ -1247,8 +1248,22 @@
 
   if (sym->attr.flavor != FL_PARAMETER)
     {
-      gfc_error ("Expected PARAMETER symbol in complex constant at %C");
-      return MATCH_ERROR;
+      /* Give the matcher for implied do-loops a chance to run.  This yields
+	 a much saner error message for "write(*,*) (i, i=1, 6" where the 
+	 right parenthesis is missing.  */
+      char c;
+      gfc_gobble_whitespace ();
+      c = gfc_peek_ascii_char ();
+      if (c == '=' || c == ',')
+	{
+	  m = MATCH_NO;
+	}
+      else
+	{
+	  gfc_error ("Expected PARAMETER symbol in complex constant at %C");
+	  m = MATCH_ERROR;
+	}
+      return m;
     }
 
   if (!sym->value)
@@ -1698,21 +1713,21 @@
       switch (name[0])
 	{
 	case 'l':
-	  if (strncmp (name, "loc", 3) == 0)
+	  if (gfc_str_startswith (name, "loc"))
 	    {
 	      result->name = "%LOC";
 	      break;
 	    }
 	  /* FALLTHRU */
 	case 'r':
-	  if (strncmp (name, "ref", 3) == 0)
+	  if (gfc_str_startswith (name, "ref"))
 	    {
 	      result->name = "%REF";
 	      break;
 	    }
 	  /* FALLTHRU */
 	case 'v':
-	  if (strncmp (name, "val", 3) == 0)
+	  if (gfc_str_startswith (name, "val"))
 	    {
 	      result->name = "%VAL";
 	      break;
@@ -2081,7 +2096,7 @@
     {
       bool permissible;
 
-      /* These target expressions can ge resolved at any time.  */
+      /* These target expressions can be resolved at any time.  */
       permissible = tgt_expr && tgt_expr->symtree && tgt_expr->symtree->n.sym
 		    && (tgt_expr->symtree->n.sym->attr.use_assoc
 			|| tgt_expr->symtree->n.sym->attr.host_assoc
@@ -2878,6 +2893,39 @@
       if (!this_comp)
 	goto cleanup;
 
+      /* For a constant string constructor, make sure the length is
+	 correct; truncate of fill with blanks if needed.  */
+      if (this_comp->ts.type == BT_CHARACTER && !this_comp->attr.allocatable
+	  && this_comp->ts.u.cl && this_comp->ts.u.cl->length
+	  && this_comp->ts.u.cl->length->expr_type == EXPR_CONSTANT
+	  && actual->expr->ts.type == BT_CHARACTER
+	  && actual->expr->expr_type == EXPR_CONSTANT)
+	{
+	  ptrdiff_t c, e;
+	  c = gfc_mpz_get_hwi (this_comp->ts.u.cl->length->value.integer);
+	  e = actual->expr->value.character.length;
+
+	  if (c != e)
+	    {
+	      ptrdiff_t i, to;
+	      gfc_char_t *dest;
+	      dest = gfc_get_wide_string (c + 1);
+
+	      to = e < c ? e : c;
+	      for (i = 0; i < to; i++)
+		dest[i] = actual->expr->value.character.string[i];
+	      
+	      for (i = e; i < c; i++)
+		dest[i] = ' ';
+
+	      dest[c] = '\0';
+	      free (actual->expr->value.character.string);
+
+	      actual->expr->value.character.length = c;
+	      actual->expr->value.character.string = dest;
+	    }
+	}
+
       comp_tail->val = actual->expr;
       if (actual->expr != NULL)
 	comp_tail->where = actual->expr->where;