re PR fortran/54997 (-Wunused-function gives false warnings)

2012-11-26  Janus Weil  <janus@gcc.gnu.org>

	PR fortran/54997
	* decl.c (match_procedure_decl): Don't set 'referenced' attribute
	for PROCEDURE declarations.
	* parse.c (gfc_fixup_sibling_symbols,parse_contained): Don't set
	'referenced' attribute for all contained procedures.
	* trans-decl.c (gfc_get_symbol_decl): Allow for unreferenced procedures.
	(build_function_decl): Set TREE_USED for referenced procedures.

2012-11-26  Janus Weil  <janus@gcc.gnu.org>

	PR fortran/54997
	* gfortran.dg/warn_unused_function_2.f90: New.

From-SVN: r193811

gcc/fortran/ChangeLog

 2012-11-26  Janus Weil  <janus@gcc.gnu.org>
 
+	PR fortran/54997
+	* decl.c (match_procedure_decl): Don't set 'referenced' attribute
+	for PROCEDURE declarations.
+	* parse.c (gfc_fixup_sibling_symbols,parse_contained): Don't set
+	'referenced' attribute for all contained procedures.
+	* trans-decl.c (gfc_get_symbol_decl): Allow for unreferenced procedures.
+	(build_function_decl): Set TREE_USED for referenced procedures.
+
+2012-11-26  Janus Weil  <janus@gcc.gnu.org>
+
 	PR fortran/54881
 	* match.c (select_derived_set_tmp,select_class_set_tmp): Removed and
 	unified into ...

gcc/fortran/decl.c

@@ -4941,8 +4941,6 @@ match_procedure_decl (void)
 
 	}
 
-      gfc_set_sym_referenced (sym);
-
       if (gfc_match_eos () == MATCH_YES)
 	return MATCH_YES;
       if (gfc_match_char (',') != MATCH_YES)

gcc/fortran/parse.c

@@ -3928,7 +3928,6 @@ gfc_fixup_sibling_symbols (gfc_symbol *sym, gfc_namespace *siblings)
   gfc_symtree *st;
   gfc_symbol *old_sym;
 
-  sym->attr.referenced = 1;
   for (ns = siblings; ns; ns = ns->sibling)
     {
       st = gfc_find_symtree (ns->sym_root, sym->name);
@@ -4050,7 +4049,6 @@ parse_contained (int module)
 	  /* Mark this as a contained function, so it isn't replaced
 	     by other module functions.  */
 	  sym->attr.contained = 1;
-	  sym->attr.referenced = 1;
 
 	  /* Set implicit_pure so that it can be reset if any of the
 	     tests for purity fail.  This is used for some optimisation

gcc/fortran/trans-decl.c

@@ -1195,6 +1195,7 @@ gfc_get_symbol_decl (gfc_symbol * sym)
   bool intrinsic_array_parameter = false;
 
   gcc_assert (sym->attr.referenced
+	      || sym->attr.flavor == FL_PROCEDURE
 	      || sym->attr.use_assoc
 	      || sym->ns->proc_name->attr.if_source == IFSRC_IFBODY
 	      || (sym->module && sym->attr.if_source != IFSRC_DECL
@@ -1851,6 +1852,9 @@ build_function_decl (gfc_symbol * sym, bool global)
 	  || sym->attr.public_used))
     TREE_PUBLIC (fndecl) = 1;
 
+  if (sym->attr.referenced || sym->attr.entry_master)
+    TREE_USED (fndecl) = 1;
+
   attributes = add_attributes_to_decl (attr, NULL_TREE);
   decl_attributes (&fndecl, attributes, 0);
 

gcc/testsuite/ChangeLog

 2012-11-26  Janus Weil  <janus@gcc.gnu.org>
 
+	PR fortran/54997
+	* gfortran.dg/warn_unused_function_2.f90: New.
+
+2012-11-26  Janus Weil  <janus@gcc.gnu.org>
+
 	PR fortran/54881
 	* gfortran.dg/associated_6.f90: New.
 	* gfortran.dg/select_type_30.f03: New.

gcc/testsuite/gfortran.dg/warn_unused_function_2.f90

+! { dg-do compile }
+! { dg-options "-Wall" }
+!
+! [4.8 Regression] PR 54997: -Wunused-function gives false warnings
+!
+! Contributed by Janus Weil <janus@gcc.gnu.org>
+
+module m
+
+  implicit none
+  private :: s1,s2,s3
+
+contains
+
+  subroutine s1            ! { dg-warning "defined but not used" }
+    call s2(s3)
+  end subroutine
+
+  subroutine s2(dummy)     ! { dg-warning "Unused dummy argument" }
+    procedure() :: dummy
+  end subroutine
+
+  subroutine s3()
+  end subroutine
+
+end module
+
+
+subroutine sub
+entry en
+end subroutine
+
+
+! { dg-final { cleanup-modules "m" } }