* opts-common.c (decode_cmdline_option): Print empty string

	argument as "" in decoded->orig_option_with_args_text.
	* gcc.c (execute): Print empty string argument as ""
	in the verbose output.
	(do_spec_1): Keep empty string argument.

	testsuite/
	* gcc.dg/cpp/include7.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@170426 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 13 insertions, 2 deletions

diff --git a/gcc/opts-common.c b/gcc/opts-common.c
index 3c4044a2063..f958b7ed953 100644
--- a/gcc/opts-common.c
+++ b/gcc/opts-common.c
@@ -607,11 +607,15 @@ decode_cmdline_option (const char **argv, unsigned int lang_mask,
     {
       if (i < result)
 	{
+	  size_t len;
 	  if (opt_index == OPT_SPECIAL_unknown)
 	    decoded->canonical_option[i] = argv[i];
 	  else
 	    decoded->canonical_option[i] = NULL;
-	  total_len += strlen (argv[i]) + 1;
+	  len = strlen (argv[i]);
+	  /* If the argument is an empty string, we will print it as "" in
+	     orig_option_with_args_text.  */
+	  total_len += (len != 0 ? len : 2) + 1;
 	}
       else
 	decoded->canonical_option[i] = NULL;
@@ -637,7 +641,14 @@ decode_cmdline_option (const char **argv, unsigned int lang_mask,
     {
       size_t len = strlen (argv[i]);
 
-      memcpy (p, argv[i], len);
+      /* Print the empty string verbally.  */
+      if (len == 0)
+	{
+	  *p++ = '"';
+	  *p++ = '"';
+	}
+      else
+	memcpy (p, argv[i], len);
       p += len;
       if (i == result - 1)
 	*p++ = 0;