[Fortran] PR39505 - add support for !GCC$ attributes NO_ARG_CHECK

2013-04-16  Tobias Burnus  <burnus@net-b.de>

	PR fortran/39505
	* gfortran.h (gfc_option_t): Add flag_directives.
        * gfortran.texi (GCC Fortran directives): Mention
	-fno-directives.
	* invoke.texi (-fno-directives): Add.
	* lang.opt (fdirectives): Add.
	* options.c (gfc_init_options, gfc_handle_option): Handle it.
	* scanner.c (skip_gcc_attribute): Ditto.

diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index a69cea2..bb4ec1b 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -2300,6 +2300,7 @@  typedef struct
   int flag_realloc_lhs;
   int flag_aggressive_function_elimination;
   int flag_frontend_optimize;
+  int flag_directives;
 
   int fpe;
   int rtcheck;
diff --git a/gcc/fortran/gfortran.texi b/gcc/fortran/gfortran.texi
index 61cb3bb..c2bb0d5 100644
--- a/gcc/fortran/gfortran.texi
+++ b/gcc/fortran/gfortran.texi
@@ -2663,6 +2663,9 @@  on the processor; see
 @ref{Top,,C Extensions,gcc,Using the GNU Compiler Collection (GCC)}
 for details.
 
+Note that the parsing of the directives can be disabled via the
+@option{-fno-directives} option.
+
 For procedures and procedure pointers, the following attributes can
 be used to change the calling convention:
 
diff --git a/gcc/fortran/invoke.texi b/gcc/fortran/invoke.texi
index 12c200e..9f250ad 100644
--- a/gcc/fortran/invoke.texi
+++ b/gcc/fortran/invoke.texi
@@ -116,7 +116,7 @@  by type.  Explanations are in the following sections.
 @xref{Fortran Dialect Options,,Options controlling Fortran dialect}.
 @gccoptlist{-fall-intrinsics -fbackslash -fcray-pointer -fd-lines-as-code @gol
 -fd-lines-as-comments -fdefault-double-8 -fdefault-integer-8 @gol
--fdefault-real-8 -fdollar-ok -ffixed-line-length-@var{n} @gol
+-fdefault-real-8 -fdirectives -fdollar-ok -ffixed-line-length-@var{n} @gol
 -ffixed-line-length-none -ffree-form -ffree-line-length-@var{n} @gol
 -ffree-line-length-none -fimplicit-none -finteger-4-integer-8 @gol
 -fmax-identifier-length -fmodule-private -fno-fixed-form -fno-range-check @gol
@@ -250,6 +250,11 @@  the kind of non-double real constants like @code{1.0}, and does promote
 the default width of @code{DOUBLE PRECISION} to 16 bytes if possible, unless
 @code{-fdefault-double-8} is given, too.
 
+@item -fno-directives
+@opindex @code{fdirectives}
+@opindex @code{fno-directives}
+Disable the GNU Fortran Compiler Directives (@code{!GCC$}) directives.
+
 @item -fdollar-ok
 @opindex @code{fdollar-ok}
 @cindex @code{$}
diff --git a/gcc/fortran/lang.opt b/gcc/fortran/lang.opt
index dbc3f6b..5fb1a13 100644
--- a/gcc/fortran/lang.opt
+++ b/gcc/fortran/lang.opt
@@ -389,6 +389,10 @@  fdollar-ok
 Fortran
 Allow dollar signs in entity names
 
+fdirectives
+Fortran
+Enable !GCC$ directives
+
 fdump-core
 Fortran Ignore
 Does nothing. Preserved for backward compatibility.
diff --git a/gcc/fortran/options.c b/gcc/fortran/options.c
index 3f5de03..00e6a50 100644
--- a/gcc/fortran/options.c
+++ b/gcc/fortran/options.c
@@ -122,6 +122,7 @@  gfc_init_options (unsigned int decoded_options_count,
   gfc_option.flag_integer4_kind = 0;
   gfc_option.flag_real4_kind = 0;
   gfc_option.flag_real8_kind = 0;
+  gfc_option.flag_directives = 1;
   gfc_option.flag_dollar_ok = 0;
   gfc_option.flag_underscoring = 1;
   gfc_option.flag_f2c = 0;
@@ -766,6 +767,10 @@  gfc_handle_option (size_t scode, const char *arg, int value,
       gfc_option.flag_d_lines = 0;
       break;
 
+    case OPT_fdirectives:
+      gfc_option.flag_directives = value;
+      break;
+
     case OPT_fdump_fortran_original:
     case OPT_fdump_parse_tree:
       gfc_option.dump_fortran_original = value;
diff --git a/gcc/fortran/scanner.c b/gcc/fortran/scanner.c
index fd8f284..8c95f90 100644
--- a/gcc/fortran/scanner.c
+++ b/gcc/fortran/scanner.c
@@ -718,6 +718,9 @@  skip_gcc_attribute (locus start)
   char c;
   locus old_loc = gfc_current_locus;
 
+  if (!gfc_option.flag_directives)
+    return false;
+
   if ((c = next_char ()) == 'g' || c == 'G')
     if ((c = next_char ()) == 'c' || c == 'C')
       if ((c = next_char ()) == 'c' || c == 'C')
@@ -770,7 +773,7 @@  skip_free_comments (void)
       if (c == '!')
 	{
 	  /* Keep the !GCC$ line.  */
-		  if (at_bol && skip_gcc_attribute (start))
+	  if (at_bol && skip_gcc_attribute (start))
 	    return false;
 
 	  /* If -fopenmp, we need to handle here 2 things: