re PR fortran/77903 ([F08] gfortran 6.1.0/7.0.0 accept invalid code with conflicting module/submodule interfaces)

2016-12-09  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/77903
	* decl.c (get_proc_name): Use the symbol tlink field instead of
	the typespec interface field.
	(gfc_match_function_decl, gfc_match_submod_proc): Ditto.
	* gfortran.h : Since the symbol tlink field is no longer used
	by the frontend for change management, change the comment to
	reflect its current uses.
	* parse.c (get_modproc_result): Same as decl.c changes.
	* resolve.c (resolve_fl_procedure): Ditto.

2016-12-09  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/77903
	* gfortran.dg/submodule_20.f08: New test.

From-SVN: r243507

gcc/fortran/ChangeLog

@@ -1,3 +1,15 @@
+2016-12-09  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/77903
+	* decl.c (get_proc_name): Use the symbol tlink field instead of
+	the typespec interface field.
+	(gfc_match_function_decl, gfc_match_submod_proc): Ditto.
+	* gfortran.h : Since the symbol tlink field is no longer used
+	by the frontend for change management, change the comment to
+	reflect its current uses.
+	* parse.c (get_modproc_result): Same as decl.c changes.
+	* resolve.c (resolve_fl_procedure): Ditto.
+
 2016-12-09  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/61767
@@ -22,7 +34,7 @@
 	* trans-expr.c (gfc_conv_procedure_call): Use the almighty deallocate_
 	with_status.
 	* trans-openmp.c (gfc_walk_alloc_comps): Likewise.
-	(gfc_omp_clause_assign_op): Likewise. 
+	(gfc_omp_clause_assign_op): Likewise.
 	(gfc_omp_clause_dtor): Likewise.
 	* trans-stmt.c (gfc_trans_deallocate): Likewise.
 	* trans.c (gfc_deallocate_with_status): Allow deallocation of scalar

gcc/fortran/decl.c

@@ -1119,12 +1119,12 @@ get_proc_name (const char *name, gfc_symbol **result, bool module_fcn_entry)
     {
       /* Create a partially populated interface symbol to carry the
 	 characteristics of the procedure and the result.  */
-      sym->ts.interface = gfc_new_symbol (name, sym->ns);
-      gfc_add_type (sym->ts.interface, &(sym->ts),
+      sym->tlink = gfc_new_symbol (name, sym->ns);
+      gfc_add_type (sym->tlink, &(sym->ts),
 		    &gfc_current_locus);
-      gfc_copy_attr (&sym->ts.interface->attr, &sym->attr, NULL);
+      gfc_copy_attr (&sym->tlink->attr, &sym->attr, NULL);
       if (sym->attr.dimension)
-	sym->ts.interface->as = gfc_copy_array_spec (sym->as);
+	sym->tlink->as = gfc_copy_array_spec (sym->as);
 
       /* Ideally, at this point, a copy would be made of the formal
 	 arguments and their namespace. However, this does not appear
@@ -1133,12 +1133,12 @@ get_proc_name (const char *name, gfc_symbol **result, bool module_fcn_entry)
 
       if (sym->result && sym->result != sym)
 	{
-	  sym->ts.interface->result = sym->result;
+	  sym->tlink->result = sym->result;
 	  sym->result = NULL;
 	}
       else if (sym->result)
 	{
-	  sym->ts.interface->result = sym->ts.interface;
+	  sym->tlink->result = sym->tlink;
 	}
     }
   else if (sym && !sym->gfc_new
@@ -6063,7 +6063,6 @@ gfc_match_function_decl (void)
 	  sym->result = result;
 	}
 
-
       /* Warn if this procedure has the same name as an intrinsic.  */
       do_warn_intrinsic_shadow (sym, true);
 
@@ -8254,11 +8253,11 @@ gfc_match_submod_proc (void)
 
   /* Make sure that the result field is appropriately filled, even though
      the result symbol will be replaced later on.  */
-  if (sym->ts.interface && sym->ts.interface->attr.function)
+  if (sym->tlink && sym->tlink->attr.function)
     {
-      if (sym->ts.interface->result
-	  && sym->ts.interface->result != sym->ts.interface)
-	sym->result= sym->ts.interface->result;
+      if (sym->tlink->result
+	  && sym->tlink->result != sym->tlink)
+	sym->result= sym->tlink->result;
       else
 	sym->result = sym;
     }

gcc/fortran/gfortran.h

@@ -1532,14 +1532,20 @@ typedef struct gfc_symbol
   gfc_namelist *namelist, *namelist_tail;
 
   /* Change management fields.  Symbols that might be modified by the
-     current statement have the mark member nonzero and are kept in a
-     singly linked list through the tlink field.  Of these symbols,
+     current statement have the mark member nonzero.  Of these symbols,
      symbols with old_symbol equal to NULL are symbols created within
      the current statement.  Otherwise, old_symbol points to a copy of
-     the old symbol.  */
-
-  struct gfc_symbol *old_symbol, *tlink;
+     the old symbol. gfc_new is used in symbol.c to flag new symbols.  */
+  struct gfc_symbol *old_symbol;
   unsigned mark:1, gfc_new:1;
+
+  /* The tlink field is used in the front end to carry the module
+     declaration of separate module procedures so that the characteristics
+     can be compared with the corresponding declaration in a submodule. In
+     translation this field carries a linked list of symbols that require
+     deferred initialization.  */
+  struct gfc_symbol *tlink;
+
   /* Nonzero if all equivalences associated with this symbol have been
      processed.  */
   unsigned equiv_built:1;

gcc/fortran/parse.c

@@ -5556,11 +5556,11 @@ get_modproc_result (void)
       proc = gfc_current_ns->proc_name ? gfc_current_ns->proc_name : NULL;
       if (proc != NULL
 	  && proc->attr.function
-	  && proc->ts.interface
-	  && proc->ts.interface->result
-	  && proc->ts.interface->result != proc->ts.interface)
+	  && proc->tlink
+	  && proc->tlink->result
+	  && proc->tlink->result != proc->tlink)
 	{
-	  gfc_copy_dummy_sym (&proc->result, proc->ts.interface->result, 1);
+	  gfc_copy_dummy_sym (&proc->result, proc->tlink->result, 1);
 	  gfc_set_sym_referenced (proc->result);
 	  proc->result->attr.if_source = IFSRC_DECL;
 	  gfc_commit_symbol (proc->result);

gcc/fortran/resolve.c

@@ -12282,10 +12282,8 @@ resolve_fl_procedure (gfc_symbol *sym, int mp_flag)
       module_name = strtok (name, ".");
       submodule_name = strtok (NULL, ".");
 
-      /* Stop the dummy characteristics test from using the interface
-	 symbol instead of 'sym'.  */
-      iface = sym->ts.interface;
-      sym->ts.interface = NULL;
+      iface = sym->tlink;
+      sym->tlink = NULL;
 
       /* Make sure that the result uses the correct charlen for deferred
 	 length results.  */
@@ -12333,7 +12331,7 @@ resolve_fl_procedure (gfc_symbol *sym, int mp_flag)
 	}
 
 check_formal:
-      /* Check the charcateristics of the formal arguments.  */
+      /* Check the characteristics of the formal arguments.  */
       if (sym->formal && sym->formal_ns)
 	{
 	  for (arg = sym->formal; arg && arg->sym; arg = arg->next)
@@ -12342,8 +12340,6 @@ check_formal:
 	      gfc_traverse_ns (sym->formal_ns, compare_fsyms);
 	    }
 	}
-
-      sym->ts.interface = iface;
     }
   return true;
 }

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2016-12-09  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/77903
+	* gfortran.dg/submodule_20.f08: New test.
+
 2016-12-09  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	PR testsuite/78740

gcc/testsuite/gfortran.dg/submodule_20.f08

@@ -0,0 +1,27 @@
+! { dg-do compile }
+!
+! Test the fix for PR77903
+!
+! Contributed by Damian Rouson  <damian@sourceryinstitute.org>
+!
+module one_module
+  implicit none
+  interface
+    module function one()
+    end function
+    integer module function two()
+    end function
+  end interface
+end module
+
+submodule(one_module) one_submodule
+  implicit none
+contains
+  integer module function one()  ! { dg-error "Type mismatch" }
+    one = 1
+  end function
+  integer(8) module function two()  ! { dg-error "Type mismatch" }
+    two = 2
+  end function
+end submodule
+