gcc: add Apple compatible -Wnewline-eof

GCC 4.2 and previous have always warned about
"No newline at end of file".

Upstream GCC removed the warning completely but
Apple made it an optional warning. Adopt it for
compatibility with older GCC and clang.

While here, add comment to complement r258712.

Obtained from:	Apple Inc. (Apple GCC 4.2 - 5531)
MFC after:	1 week

contrib/gcc/c-opts.c

@@ -487,6 +487,12 @@ c_common_handle_option (size_t scode, const char *arg, int value)
       cpp_opts->warn_multichar = value;
       break;
 
+      /* APPLE LOCAL begin -Wnewline-eof */
+    case OPT_Wnewline_eof:
+      cpp_opts->warn_newline_at_eof = value;
+      break;
+      /* APPLE LOCAL end -Wnewline-eof */
+
     case OPT_Wnormalized_:
       if (!value || (arg && strcasecmp (arg, "none") == 0))
 	cpp_opts->warn_normalize = normalized_none;

contrib/gcc/c.opt

@@ -292,6 +292,12 @@ Wnested-externs
 C ObjC Var(warn_nested_externs)
 Warn about \"extern\" declarations not at file scope
 
+; APPLE LOCAL begin -Wnewline-eof
+Wnewline-eof
+C ObjC C++ ObjC++
+Warn about files missing a newline at the end of the file
+; APPLE LOCAL end -Wnewline-eof
+
 Wnon-template-friend
 C++ ObjC++ Var(warn_nontemplate_friend) Init(1)
 Warn when non-templatized friend functions are declared within a template

contrib/gcc/doc/invoke.texi

@@ -169,6 +169,8 @@ in the following sections.
 -trigraphs  -no-integrated-cpp  -traditional  -traditional-cpp @gol
 -fallow-single-precision  -fcond-mismatch -flax-vector-conversions @gol
 -fsigned-bitfields  -fsigned-char @gol
+@c APPLE LOCAL -Wnewline-eof 2001-08-23 --sts **
+-Wnewline-eof (Apple compatible) @gol
 -funsigned-bitfields  -funsigned-char}
 
 @item C++ Language Options
@@ -2082,6 +2084,12 @@ Inhibit all warning messages.
 @opindex Wno-import
 Inhibit warning messages about the use of @samp{#import}.
 
+@c APPLE LOCAL begin -Wnewline-eof 2001-08-23 --sts **
+@item -Wnewline-eof
+@opindex Wnewline-eof
+Warn about files missing a newline at the end of the file.  (FreeBSD ONLY)
+@c APPLE LOCAL end -Wnewline-eof 2001-08-23 --sts **
+
 @item -Wchar-subscripts
 @opindex Wchar-subscripts
 Warn if an array subscript has type @code{char}.  This is a common cause

contrib/gcclibs/libcpp/ChangeLog.apple

@@ -0,0 +1,9 @@
+2008-08-04  Bill Wendling  <wendling@apple.com>
+
+        Radar 6121572
+        * charset.c (_cpp_convert_input): Don't read to.text[-1].
+
+2005-02-17  Devang Patel  <dpatel@apple.com>
+
+	Radar 3958387
+	* libcpp/lex.c (_cpp_get_fresh_line): Check warn_newline_at_eof.

contrib/gcclibs/libcpp/charset.c

@@ -1628,6 +1628,7 @@ _cpp_convert_input (cpp_reader *pfile, const char *input_charset,
      terminate with another \r, not an \n, so that we do not mistake
      the \r\n sequence for a single DOS line ending and erroneously
      issue the "No newline at end of file" diagnostic.  */
+  /* APPLE LOCAL don't access to.text[-1] radar 6121572 */
   if (to.len > 0 && to.text[to.len - 1] == '\r')
     to.text[to.len] = '\r';
   else

contrib/gcclibs/libcpp/include/cpplib.h

@@ -320,6 +320,11 @@ struct cpp_options
   /* Nonzero means warn if there are any trigraphs.  */
   unsigned char warn_trigraphs;
 
+  /* APPLE LOCAL begin -Wnewline-eof 2001-08-23 --sts */
+  /* Nonzero means warn if no newline at end of file.  */
+  unsigned char warn_newline_at_eof;
+  /* APPLE LOCAL end -Wnewline-eof 2001-08-23 --sts */
+
   /* Nonzero means warn about multicharacter charconsts.  */
   unsigned char warn_multichar;
 

contrib/gcclibs/libcpp/init.c

@@ -146,6 +146,10 @@ cpp_create_reader (enum c_lang lang, hash_table *table,
   pfile = XCNEW (cpp_reader);
 
   cpp_set_lang (pfile, lang);
+  /* APPLE LOCAL begin -Wnewline-eof 2001-08-23 --sts */
+  /* Suppress warnings about missing newlines at ends of files.  */
+  CPP_OPTION (pfile, warn_newline_at_eof) = 0;
+  /* APPLE LOCAL end -Wnewline-eof 2001-08-23 --sts */
   CPP_OPTION (pfile, warn_multichar) = 1;
   CPP_OPTION (pfile, discard_comments) = 1;
   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;

contrib/gcclibs/libcpp/lex.c

@@ -854,6 +854,14 @@ _cpp_get_fresh_line (cpp_reader *pfile)
 	{
 	  /* Clip to buffer size.  */
 	  buffer->next_line = buffer->rlimit;
+	  /* APPLE LOCAL begin suppress no newline warning.  */
+	  if ( CPP_OPTION (pfile, warn_newline_at_eof))
+	    {
+	      cpp_error_with_line (pfile, CPP_DL_PEDWARN, pfile->line_table->highest_line,
+				   CPP_BUF_COLUMN (buffer, buffer->cur),
+				   "no newline at end of file");
+	    }
+	  /* APPLE LOCAL end suppress no newline warning.  */
 	}
 
       return_at_eof = buffer->return_at_eof;