re PR fortran/42309 (Problem with a pointer array passed to a subroutine)

2010-02-05  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/42309
	* trans-expr.c (gfc_conv_subref_array_arg): Add new argument
	'formal_ptr'. If this is true, give returned descriptor unity
	lbounds, in all dimensions, and the appropriate offset.
	(gfc_conv_procedure_call); If formal is a pointer, set the last
	argument of gfc_conv_subref_array_arg to true.
	* trans.h : Add last argument for gfc_conv_subref_array_arg.
	* trans-io.c (set_internal_unit, gfc_trans_transfer): Set the
	new arg of gfc_conv_subref_array_arg to false.
	* trans-stmt.c (forall_make_variable_temp): The same.

2010-02-05  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/42309
	* gfortran.dg/subref_array_pointer_4.f90 : New test.

From-SVN: r156512

7 files changed, 91 insertions, 7 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 8a69b42..6d52e5d 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,16 @@
+2010-02-05  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/42309
+	* trans-expr.c (gfc_conv_subref_array_arg): Add new argument
+	'formal_ptr'. If this is true, give returned descriptor unity
+	lbounds, in all dimensions, and the appropriate offset.
+	(gfc_conv_procedure_call); If formal is a pointer, set the last
+	argument of gfc_conv_subref_array_arg to true.
+	* trans.h : Add last argument for gfc_conv_subref_array_arg.
+	* trans-io.c (set_internal_unit, gfc_trans_transfer): Set the
+	new arg of gfc_conv_subref_array_arg to false.
+	* trans-stmt.c (forall_make_variable_temp): The same.
+
 2010-02-03  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/42936
diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index b5091a9..4a70e73 100644
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -2294,8 +2294,8 @@ gfc_apply_interface_mapping (gfc_interface_mapping * mapping,
    an actual argument derived type array is copied and then returned
    after the function call.  */
 void
-gfc_conv_subref_array_arg (gfc_se * parmse, gfc_expr * expr,
-			   int g77, sym_intent intent)
+gfc_conv_subref_array_arg (gfc_se * parmse, gfc_expr * expr, int g77,
+			   sym_intent intent, bool formal_ptr)
 {
   gfc_se lse;
   gfc_se rse;
@@ -2308,6 +2308,7 @@ gfc_conv_subref_array_arg (gfc_se * parmse, gfc_expr * expr,
   tree tmp_index;
   tree tmp;
   tree base_type;
+  tree size;
   stmtblock_t body;
   int n;
 
@@ -2501,6 +2502,42 @@ gfc_conv_subref_array_arg (gfc_se * parmse, gfc_expr * expr,
   if (expr->ts.type == BT_CHARACTER)
     parmse->string_length = expr->ts.u.cl->backend_decl;
 
+  /* Determine the offset for pointer formal arguments and set the
+     lbounds to one.  */
+  if (formal_ptr)
+    {
+      size = gfc_index_one_node;
+      offset = gfc_index_zero_node;  
+      for (n = 0; n < info->dimen; n++)
+	{
+	  tmp = gfc_conv_descriptor_ubound_get (parmse->expr,
+						gfc_rank_cst[n]);
+	  tmp = fold_build2 (PLUS_EXPR, gfc_array_index_type,
+			     tmp, gfc_index_one_node);
+	  gfc_conv_descriptor_ubound_set (&parmse->pre,
+					  parmse->expr,
+					  gfc_rank_cst[n],
+					  tmp);
+	  gfc_conv_descriptor_lbound_set (&parmse->pre,
+					  parmse->expr,
+					  gfc_rank_cst[n],
+					  gfc_index_one_node);
+	  size = gfc_evaluate_now (size, &parmse->pre);
+	  offset = fold_build2 (MINUS_EXPR, gfc_array_index_type,
+				offset, size);
+	  offset = gfc_evaluate_now (offset, &parmse->pre);
+	  tmp = fold_build2 (MINUS_EXPR, gfc_array_index_type,
+			     rse.loop->to[n], rse.loop->from[n]);
+	  tmp = fold_build2 (PLUS_EXPR, gfc_array_index_type,
+			     tmp, gfc_index_one_node);
+	  size = fold_build2 (MULT_EXPR, gfc_array_index_type,
+			      size, tmp);
+	}
+
+      gfc_conv_descriptor_offset_set (&parmse->pre, parmse->expr,
+				      offset);
+    }
+
   /* We want either the address for the data or the address of the descriptor,
      depending on the mode of passing array arguments.  */
   if (g77)
@@ -3005,7 +3042,8 @@ gfc_conv_procedure_call (gfc_se * se, gfc_symbol * sym,
 		   is converted to a temporary, which is passed and then
 		   written back after the procedure call.  */
 		gfc_conv_subref_array_arg (&parmse, e, f,
-			fsym ? fsym->attr.intent : INTENT_INOUT);
+				fsym ? fsym->attr.intent : INTENT_INOUT,
+				fsym && fsym->attr.pointer);
 	      else
 	        gfc_conv_array_parameter (&parmse, e, argss, f, fsym,
 					  sym->name, NULL);
diff --git a/gcc/fortran/trans-io.c b/gcc/fortran/trans-io.c
index 690464e..30561bb 100644
--- a/gcc/fortran/trans-io.c
+++ b/gcc/fortran/trans-io.c
@@ -741,7 +741,7 @@ set_internal_unit (stmtblock_t * block, stmtblock_t * post_block,
 	  /* Use a temporary for components of arrays of derived types
 	     or substring array references.  */
 	  gfc_conv_subref_array_arg (&se, e, 0,
-		last_dt == READ ? INTENT_IN : INTENT_OUT);
+		last_dt == READ ? INTENT_IN : INTENT_OUT, false);
 	  tmp = build_fold_indirect_ref_loc (input_location,
 					 se.expr);
 	  se.expr = gfc_build_addr_expr (pchar_type_node, tmp);
@@ -2211,7 +2211,7 @@ gfc_trans_transfer (gfc_code * code)
 	  if (seen_vector && last_dt == READ)
 	    {
 	      /* Create a temp, read to that and copy it back.  */
-	      gfc_conv_subref_array_arg (&se, expr, 0, INTENT_OUT);
+	      gfc_conv_subref_array_arg (&se, expr, 0, INTENT_OUT, false);
 	      tmp =  se.expr;
 	    }
 	  else
diff --git a/gcc/fortran/trans-stmt.c b/gcc/fortran/trans-stmt.c
index dd3d10d..84c3c85 100644
--- a/gcc/fortran/trans-stmt.c
+++ b/gcc/fortran/trans-stmt.c
@@ -1800,7 +1800,7 @@ forall_make_variable_temp (gfc_code *c, stmtblock_t *pre, stmtblock_t *post)
   if (old_sym->attr.dimension)
     {
       gfc_init_se (&tse, NULL);
-      gfc_conv_subref_array_arg (&tse, e, 0, INTENT_IN);
+      gfc_conv_subref_array_arg (&tse, e, 0, INTENT_IN, false);
       gfc_add_block_to_block (pre, &tse.pre);
       gfc_add_block_to_block (post, &tse.post);
       tse.expr = build_fold_indirect_ref_loc (input_location, tse.expr);
diff --git a/gcc/fortran/trans.h b/gcc/fortran/trans.h
index 27b040a..30a7753 100644
--- a/gcc/fortran/trans.h
+++ b/gcc/fortran/trans.h
@@ -315,7 +315,7 @@ int gfc_is_intrinsic_libcall (gfc_expr *);
 int gfc_conv_procedure_call (gfc_se *, gfc_symbol *, gfc_actual_arglist *,
 			    gfc_expr *, tree);
 
-void gfc_conv_subref_array_arg (gfc_se *, gfc_expr *, int, sym_intent);
+void gfc_conv_subref_array_arg (gfc_se *, gfc_expr *, int, sym_intent, bool);
 
 /* gfc_trans_* shouldn't call push/poplevel, use gfc_push/pop_scope */
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4a4273e..94ccbc4 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-02-05  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/42309
+	* gfortran.dg/subref_array_pointer_4.f90 : New test.
+
 2010-02-04  Richard Guenther  <rguenther@suse.de>
 
 	PR rtl-optimization/42952
diff --git a/gcc/testsuite/gfortran.dg/subref_array_pointer_4.f90 b/gcc/testsuite/gfortran.dg/subref_array_pointer_4.f90
new file mode 100644
index 0000000..19edfdc
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/subref_array_pointer_4.f90
@@ -0,0 +1,28 @@
+! { dg-do run }
+! Tests the fix for PR42309, in which the indexing of 'Q'
+! was off by one.
+!
+! Contributed by Gilbert Scott <gilbert.scott@easynet.co.uk>
+!
+PROGRAM X
+  TYPE T
+    INTEGER :: I
+    REAL :: X
+  END TYPE T
+  TYPE(T), TARGET :: T1(0:3)
+  INTEGER, POINTER :: P(:)
+  REAL :: SOURCE(4) = [10., 20., 30., 40.]
+
+  T1%I = [1, 2, 3, 4]
+  T1%X = SOURCE
+  P => T1%I
+  CALL Z(P)
+  IF (ANY (T1%I .NE. [999, 2, 999, 4])) CALL ABORT
+  IF (ANY (T1%X .NE. SOURCE)) CALL ABORT
+CONTAINS
+  SUBROUTINE Z(Q)
+    INTEGER, POINTER :: Q(:)
+    Q(1:3:2) = 999
+  END SUBROUTINE Z
+END PROGRAM X
+