re PR fortran/78474 ([F08] gfortran accepts invalid submodule syntax)

2016-11-27  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/78474
	* module.c (gfc_match_submodule): If there is more than one
	colon, it is a syntax error.

	PR fortran/78331
	* module.c (gfc_use_module): If an smod file does not exist it
	is either because the module does not have a module procedure
	interface or there is an error in the module.

2016-11-27  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/78474
	* gfortran.dg/submodule_22.f08: New test.

	PR fortran/78331
	* gfortran.dg/submodule_21.f08: New test.

From-SVN: r242900

gcc/fortran/ChangeLog

+2016-11-27  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/78474
+	* module.c (gfc_match_submodule): If there is more than one
+	colon, it is a syntax error.
+
+	PR fortran/78331
+	* module.c (gfc_use_module): If an smod file does not exist it
+	is either because the module does not have a module procedure
+	interface or there is an error in the module.
+
 2016-11-25  Janne Blomqvist  <jb@gcc.gnu.org>
 
 	* intrinsic.texi: Fix ptrdiff_t typo in ISO_C_BINDING constants

gcc/fortran/module.c

@@ -740,6 +740,7 @@ gfc_match_submodule (void)
   match m;
   char name[GFC_MAX_SYMBOL_LEN + 1];
   gfc_use_list *use_list;
+  bool seen_colon = false;
 
   if (!gfc_notify_std (GFC_STD_F2008, "SUBMODULE declaration at %C"))
     return MATCH_ERROR;
@@ -772,7 +773,7 @@ gfc_match_submodule (void)
 	}
       else
 	{
-	module_list = use_list;
+	  module_list = use_list;
 	  use_list->module_name = gfc_get_string (name);
 	  use_list->submodule_name = use_list->module_name;
 	}
@@ -780,8 +781,11 @@ gfc_match_submodule (void)
       if (gfc_match_char (')') == MATCH_YES)
 	break;
 
-      if (gfc_match_char (':') != MATCH_YES)
+      if (gfc_match_char (':') != MATCH_YES
+	  || seen_colon)
 	goto syntax;
+
+      seen_colon = true;
     }
 
   m = gfc_match (" %s%t", &gfc_new_block);
@@ -6926,8 +6930,17 @@ gfc_use_module (gfc_use_list *module)
     }
 
   if (module_fp == NULL)
-    gfc_fatal_error ("Can't open module file %qs for reading at %C: %s",
-		     filename, xstrerror (errno));
+    {
+      if (gfc_state_stack->state != COMP_SUBMODULE
+	  && module->submodule_name == NULL)
+	gfc_fatal_error ("Can't open module file %qs for reading at %C: %s",
+			 filename, xstrerror (errno));
+      else
+	gfc_fatal_error ("Module file %qs has not been generated, either "
+			 "because the module does not contain a MODULE "
+			 "PROCEDURE or there is an error in the module.",
+			 filename);
+    }
 
   /* Check that we haven't already USEd an intrinsic module with the
      same name.  */

gcc/testsuite/ChangeLog

+2016-11-27  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/78474
+	* gfortran.dg/submodule_22.f08: New test.
+
+	PR fortran/78331
+	* gfortran.dg/submodule_21.f08: New test.
+
 2016-11-27  John David Anglin  <danglin@gcc.gnu.org>
 
 	* g++.dg/torture/pr65655.C: Use dg-timeout-factor 2.

gcc/testsuite/gfortran.dg/submodule_21.f08

+! { dg-do compile }
+!
+! Test the fix for PR78331.
+!
+! Reported on https://groups.google.com/forum/#!topic/comp.lang.fortran/NFCF9brKksg
+!
+MODULE MainModule
+END MODULE MainModule
+
+SUBMODULE (MainModule) MySub1
+  IMPLICIT NONE
+  INTEGER, PARAMETER :: a = 17
+END SUBMODULE MySub1
+
+PROGRAM MyProg
+  USE MainModule
+  WRITE(*,*) a
+END PROGRAM MyProg
+! { dg-excess-errors "does not contain a MODULE PROCEDURE" }

gcc/testsuite/gfortran.dg/submodule_22.f08

+! { dg-do compile }
+!
+! Test the fix for PR78474.
+!
+! Contributed by Nicholas Brearly  <nick.brealey@cobham.com>
+!
+module mtop
+  implicit none
+  real :: r
+  interface
+    module subroutine sub1()
+    end subroutine
+  end interface
+  interface
+    module subroutine sub2()
+    end subroutine
+  end interface
+  interface
+    module subroutine sub3()
+    end subroutine
+  end interface
+end module mtop
+
+submodule (mtop) submod
+  implicit none
+  real :: s
+contains
+  module subroutine sub1
+    r = 0.0
+  end subroutine sub1
+end
+
+submodule (mtop:submod) subsubmod
+contains
+  module subroutine sub2
+    r = 1.0
+    s = 1.0
+  end subroutine sub2
+end
+
+submodule (mtop:submod:subsubmod) subsubsubmod ! { dg-error "Syntax error in SUBMODULE statement" }
+contains
+  module subroutine sub3
+    r = 2.0
+    s = 2.0
+  end subroutine sub3
+end