re PR fortran/38407 (Wishlist: -Wunused-dummy-argument and -Wno-unused-dummy-argument)

gcc/fortran/:
2010-05-20  Daniel Franke  <franke.daniel@gmail.com>

        PR fortran/38407
        * lang.opt (Wunused-dummy-argument): New option.
        * gfortran.h (gfc_option_t): Add warn_unused_dummy_argument.
        * options.c (gfc_init_options): Disable warn_unused_dummy_argument.
        (set_Wall): Enable warn_unused_dummy_argument.
        (gfc_handle_option): Set warn_unused_dummy_argument according to
        command line.
        * trans-decl.c (generate_local_decl): Separate warnings about
        unused variables and unused dummy arguments.
        * invoke.texi: Documented new option.

gcc/testsuite/:
2010-05-20  Daniel Franke  <franke.daniel@gmail.com>

        PR fortran/38407
        * warn_unused_dummy_argument_1.f90: New.
        * warn_unused_dummy_argument_2.f90: New.

From-SVN: r159641

gcc/fortran/ChangeLog

@@ -1,3 +1,16 @@
+2010-05-20  Daniel Franke  <franke.daniel@gmail.com>
+
+        PR fortran/38407
+        * lang.opt (Wunused-dummy-argument): New option.
+        * gfortran.h (gfc_option_t): Add warn_unused_dummy_argument.
+        * options.c (gfc_init_options): Disable warn_unused_dummy_argument.
+        (set_Wall): Enable warn_unused_dummy_argument.
+        (gfc_handle_option): Set warn_unused_dummy_argument according to
+        command line.
+        * trans-decl.c (generate_local_decl): Separate warnings about
+        unused variables and unused dummy arguments.
+        * invoke.texi: Documented new option.
+
 2010-05-20  Steven Bosscher  <steven@gcc.gnu.org>
 
 	* trans-expr.c: Do not include convert.h, ggc.h, real.h, and gimple.h.

gcc/fortran/gfortran.h

@@ -2117,6 +2117,7 @@ typedef struct
   int warn_character_truncation;
   int warn_array_temp;
   int warn_align_commons;
+  int warn_unused_dummy_argument;
   int max_errors;
 
   int flag_all_intrinsics;

gcc/fortran/invoke.texi

@@ -690,7 +690,8 @@ Enables commonly used warning options pertaining to usage that
 we recommend avoiding and that we believe are easy to avoid.
 This currently includes @option{-Waliasing}, @option{-Wampersand}, 
 @option{-Wconversion}, @option{-Wsurprising}, @option{-Wintrinsics-std},
-@option{-Wno-tabs}, @option{-Wintrinsic-shadow} and @option{-Wline-truncation}.
+@option{-Wno-tabs}, @option{-Wintrinsic-shadow}, @option{-Wline-truncation},
+and @option{-Wunused}.
 
 @item -Waliasing
 @opindex @code{Waliasing}
@@ -832,15 +833,22 @@ intrinsic; in this case, an explicit interface or @code{EXTERNAL} or
 @code{INTRINSIC} declaration might be needed to get calls later resolved to
 the desired intrinsic/procedure.
 
+@item -Wunused-dummy-argument
+@opindex @code{Wunused-dummy-argument}
+@cindex warnings, unused dummy argument
+@cindex unused dummy argument
+@cindex dummy argument, unused
+Warn about unused dummy arguments. This option is implied by @option{-Wall}.
+
 @item -Wunused-parameter
 @opindex @code{Wunused-parameter}
 @cindex warnings, unused parameter
 @cindex unused parameter
 Contrary to @command{gcc}'s meaning of @option{-Wunused-parameter},
 @command{gfortran}'s implementation of this option does not warn
-about unused dummy arguments, but about unused @code{PARAMETER} values.
-@option{-Wunused-parameter} is not included in @option{-Wall} but is
-implied by @option{-Wall -Wextra}.
+about unused dummy arguments (see @option{-Wunused-dummy-argument}),
+but about unused @code{PARAMETER} values. @option{-Wunused-parameter}
+is not included in @option{-Wall} but is implied by @option{-Wall -Wextra}.
 
 @item -Walign-commons
 @opindex @code{Walign-commons}

gcc/fortran/lang.opt

@@ -132,6 +132,10 @@ Wintrinsic-shadow
 Fortran Warning
 Warn if a user-procedure has the same name as an intrinsic
 
+Wunused-dummy-argument
+Fortran Warning
+Warn about unused dummy arguments.
+
 cpp
 Fortran Joined Separate Negative(nocpp)
 Enable preprocessing

gcc/fortran/options.c

@@ -87,6 +87,7 @@ gfc_init_options (unsigned int argc, const char **argv)
   gfc_option.warn_intrinsic_shadow = 0;
   gfc_option.warn_intrinsics_std = 0;
   gfc_option.warn_align_commons = 1;
+  gfc_option.warn_unused_dummy_argument = 0;
   gfc_option.max_errors = 25;
 
   gfc_option.flag_all_intrinsics = 0;
@@ -417,6 +418,7 @@ set_Wall (int setting)
   gfc_option.warn_intrinsic_shadow = setting;
   gfc_option.warn_intrinsics_std = setting;
   gfc_option.warn_character_truncation = setting;
+  gfc_option.warn_unused_dummy_argument = setting;
 
   warn_unused = setting;
   warn_return_type = setting;
@@ -616,6 +618,10 @@ gfc_handle_option (size_t scode, const char *arg, int value,
       gfc_option.warn_align_commons = value;
       break;
 
+    case OPT_Wunused_dummy_argument:
+      gfc_option.warn_unused_dummy_argument = value;
+      break;
+
     case OPT_fall_intrinsics:
       gfc_option.flag_all_intrinsics = 1;
       break;

gcc/fortran/trans-decl.c

@@ -3878,24 +3878,29 @@ generate_local_decl (gfc_symbol * sym)
 
       if (sym->attr.referenced)
 	gfc_get_symbol_decl (sym);
-      /* INTENT(out) dummy arguments are likely meant to be set.  */
-      else if (warn_unused_variable
-	       && sym->attr.dummy
-	       && sym->attr.intent == INTENT_OUT)
+
+      /* Warnings for unused dummy arguments.  */
+      else if (sym->attr.dummy)
 	{
-	  if (sym->ts.type != BT_DERIVED)
-	    gfc_warning ("Dummy argument '%s' at %L was declared INTENT(OUT) "
-		         "but was not set",  sym->name, &sym->declared_at);
-	  else if (!gfc_has_default_initializer (sym->ts.u.derived))
-	    gfc_warning ("Derived-type dummy argument '%s' at %L was "
-			 "declared INTENT(OUT) but was not set and does "
-			 "not have a default initializer",
-			 sym->name, &sym->declared_at);
+	  /* INTENT(out) dummy arguments are likely meant to be set.  */
+	  if (gfc_option.warn_unused_dummy_argument
+	      && sym->attr.intent == INTENT_OUT)
+	    {
+	      if (sym->ts.type != BT_DERIVED)
+		gfc_warning ("Dummy argument '%s' at %L was declared "
+			     "INTENT(OUT) but was not set",  sym->name,
+			     &sym->declared_at);
+	      else if (!gfc_has_default_initializer (sym->ts.u.derived))
+		gfc_warning ("Derived-type dummy argument '%s' at %L was "
+			     "declared INTENT(OUT) but was not set and "
+			     "does not have a default initializer",
+			     sym->name, &sym->declared_at);
+	    }
+	  else if (gfc_option.warn_unused_dummy_argument)
+	    gfc_warning ("Unused dummy argument '%s' at %L", sym->name,
+			 &sym->declared_at);
 	}
-      /* Specific warning for unused dummy arguments. */
-      else if (warn_unused_variable && sym->attr.dummy)
-	gfc_warning ("Unused dummy argument '%s' at %L", sym->name,
-		     &sym->declared_at);
+
       /* Warn for unused variables, but not if they're inside a common
 	 block or are use-associated.  */
       else if (warn_unused_variable

gcc/testsuite/ChangeLog

@@ -1,3 +1,9 @@
+2010-05-20  Daniel Franke  <franke.daniel@gmail.com>
+
+        PR fortran/38407
+        * warn_unused_dummy_argument_1.f90: New.
+        * warn_unused_dummy_argument_2.f90: New.
+
 2010-05-20  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/30298

gcc/testsuite/gfortran.dg/warn_unused_dummy_argument_1.f90

@@ -0,0 +1,10 @@
+! { dg-do "compile" }
+! { dg-options "-Wall" }
+!
+! PR fortran/38407
+!
+
+SUBROUTINE s(dummy)                ! { dg-warning "Unused dummy" }
+  INTEGER, INTENT(in) :: dummy
+  INTEGER :: variable              ! { dg-warning "Unused variable" }
+END SUBROUTINE

gcc/testsuite/gfortran.dg/warn_unused_dummy_argument_2.f90

@@ -0,0 +1,10 @@
+! { dg-do "compile" }
+! { dg-options "-Wall -Wno-unused-dummy-argument" }
+!
+! PR fortran/38407
+!
+
+SUBROUTINE s(dummy)
+  INTEGER, INTENT(in) :: dummy
+  INTEGER :: variable              ! { dg-warning "Unused variable" }
+END SUBROUTINE