From: Thomas Koenig <tkoenig@gcc.gnu.org>
Date: Sun, 15 Sep 2019 19:48:41 +0000 (+0000)
Subject: backport: re PR fortran/91557 (Bogus warning about unused dummy argument _formal_*)
X-Git-Tag: releases/gcc-9.3.0~622
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=121cc969e61954f1b8b40d8a9caa279b289f3710;p=thirdparty%2Fgcc.git

backport: re PR fortran/91557 (Bogus warning about unused dummy argument _formal_*)

2019-09-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

    Backport from trunk
    PR fortran/91557
    * trans-decl.c (generate_local_decl): Do not warn if the symbol
    is artificial.
    * trans-types.c (get_formal_from_actual_arglist): Set artificial
    attribute on dummy arguments.

2019-09-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

    Backport from trunk
    PR fortran/91557
    * gfortran.dg/warn_unused_dummy_argument_5.f90: New test.

From-SVN: r275733
---

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 19a3e0c68179..44c139406252 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,12 @@
+2019-09-15  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	Backport from trunk
+	PR fortran/91557
+	* trans-decl.c (generate_local_decl): Do not warn if the symbol
+	is artificial.
+	* trans-types.c (get_formal_from_actual_arglist): Set artificial
+	attribute on dummy arguments.
+
 2019-09-14  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/91553
diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index 5d1d1ecb19c8..f5149eed981b 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -5862,9 +5862,11 @@ generate_local_decl (gfc_symbol * sym)
 	    }
 	  else if (warn_unused_dummy_argument)
 	    {
-	      gfc_warning (OPT_Wunused_dummy_argument,
-			   "Unused dummy argument %qs at %L", sym->name,
-			   &sym->declared_at);
+	      if (!sym->attr.artificial)
+		gfc_warning (OPT_Wunused_dummy_argument,
+			     "Unused dummy argument %qs at %L", sym->name,
+			     &sym->declared_at);
+
 	      if (sym->backend_decl != NULL_TREE)
 		TREE_NO_WARNING(sym->backend_decl) = 1;
 	    }
diff --git a/gcc/fortran/trans-types.c b/gcc/fortran/trans-types.c
index d3b61e78887f..3c8188b30c4e 100644
--- a/gcc/fortran/trans-types.c
+++ b/gcc/fortran/trans-types.c
@@ -3021,6 +3021,7 @@ get_formal_from_actual_arglist (gfc_symbol *sym, gfc_actual_arglist *actual_args
 		}
 	    }
 	  s->attr.dummy = 1;
+	  s->attr.artificial = 1;
 	  s->attr.intent = INTENT_UNKNOWN;
 	  (*f)->sym = s;
 	}
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0df33c2333f0..6bb23d64b982 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2019-09-15  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	Backport from trunk
+	PR fortran/91557
+	* gfortran.dg/warn_unused_dummy_argument_5.f90: New test.
+
 2019-09-14  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/91553
diff --git a/gcc/testsuite/gfortran.dg/warn_unused_dummy_argument_5.f90 b/gcc/testsuite/gfortran.dg/warn_unused_dummy_argument_5.f90
new file mode 100644
index 000000000000..fa93f1d7ff27
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/warn_unused_dummy_argument_5.f90
@@ -0,0 +1,16 @@
+! { dg-do compile }
+! { dg-additional-options "-Wunused-dummy-argument" }
+! PR 91557 - this used to generate a bogus warning
+! Test case by Gerhard Steinmetz
+program p
+   integer :: a, b
+   a = 1
+   call g
+contains
+   subroutine g
+      integer :: x, y
+      call h (x, y)
+      if ( a > 0 )   y = y - 1
+      b = y - x + 1
+   end
+end