Two of Eef's bugs, was: Re: gfortran

[Steven Bosscher]

On Friday 22 December 2006 16:19, Tobias Schlüter wrote:
> Anyway, in the course of our off-list discussion he pointed out two
> bugs: the first is now the embarassing PR30278

I think the attached patch shows what the fix should look like.  I'm not
100% sure if this is right, though.  I've asked PaulT and Steve for their
opinions, but I might as well post it here in the mean time.

$ cat t.f
      call wrt('\\backslash')
      write (*,200)
      stop
 200  format ('\\backslash now results in \\backslash')
      end

      subroutine wrt(a)
      character*(*) a
      lena = len(a)
      write(*,*) 'results in: ', a(1:lena)
      return
      end
$ g77-hammer t.f -static
$ ./a.out
 results in: \backslash
\backslash now results in \backslash
$ /opt/experimental/bin/gfortran-20061223-PR30278 t.f -static
$ ./a.out
 results in: \backslash
\backslash now results in \backslash
$
$
$ g77-hammer t.f -static -fno-backslash
$ ./a.out
 results in: \\backslash
\\backslash now results in \\backslash
$ /opt/experimental/bin/gfortran-20061223-PR30278 t.f -static -fno-backslash
$ ./a.out
 results in: \\backslash
\\backslash now results in \\backslash
$

It's a bit of copy-and-paste from a similar function in primary.c.  We
should probably make the two functions share some code (into a function
maybe_escaped_character or something...).

Gr.
Steven

	* io.c (next_char): Handle escaped characters if flag_backslash.

Index: io.c
===================================================================
--- io.c	(revision 120167)
+++ io.c	(working copy)
@@ -137,11 +137,49 @@ next_char (int in_string)
       c = gfc_next_char_literal (in_string);
       if (c == '\n')
 	c = '\0';
+    }
+
+  if (gfc_option.flag_backslash && c == '\\')
+    {
+      locus old_locus = gfc_current_locus;
+
+      switch (gfc_next_char_literal (1))
+	{
+	case 'a':
+	  c = '\a';
+	  break;
+	case 'b':
+	  c = '\b';
+	  break;
+	case 't':
+	  c = '\t';
+	  break;
+	case 'f':
+	  c = '\f';
+	  break;
+	case 'n':
+	  c = '\n';
+	  break;
+	case 'r':
+	  c = '\r';
+	  break;
+	case 'v':
+	  c = '\v';
+	  break;
+	case '\\':
+	  c = '\\';
+	  break;
 
-      if (mode == MODE_COPY)
-	*format_string++ = c;
+	default:
+	  /* Unknown backslash codes are simply not expanded.  */
+	  gfc_current_locus = old_locus;
+	  break;
+	}
     }
 
+  if (mode == MODE_COPY)
+    *format_string++ = c;
+
   c = TOUPPER (c);
   return c;
 }