re PR fortran/27965 (invalid "Array bound mismatch" runtime error)

	PR fortran/27965
	* trans-array.c (gfc_conv_ss_startstride): Correct the runtime
	conditions for bounds-checking. Check for nonzero stride.
	Don't check the last dimension of assumed-size arrays. Fix the
	dimension displayed in the error message.

From-SVN: r114724

2 files changed, 89 insertions, 12 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index d94a748..8ac4cef 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,11 @@
+2006-06-16  Francois-Xavier Coudert  <coudert@clipper.ens.fr>
+
+	PR fortran/27965
+	* trans-array.c (gfc_conv_ss_startstride): Correct the runtime
+	conditions for bounds-checking. Check for nonzero stride.
+	Don't check the last dimension of assumed-size arrays. Fix the
+	dimension displayed in the error message.
+
 2006-06-15  Thomas Koenig <Thomas.Koenig@online.de>
 
 	* trans-array.h (gfc_trans_create_temp_array):  Add bool
diff --git a/gcc/fortran/trans-array.c b/gcc/fortran/trans-array.c
index a8a8aa6..941e711 100644
--- a/gcc/fortran/trans-array.c
+++ b/gcc/fortran/trans-array.c
@@ -2524,9 +2524,10 @@ gfc_conv_ss_startstride (gfc_loopinfo * loop)
   if (flag_bounds_check)
     {
       stmtblock_t block;
-      tree bound;
+      tree lbound, ubound;
       tree end;
       tree size[GFC_MAX_DIMENSIONS];
+      tree stride_pos, stride_neg, non_zerosized, tmp2;
       gfc_ss_info *info;
       char *msg;
       int dim;
@@ -2551,25 +2552,93 @@ gfc_conv_ss_startstride (gfc_loopinfo * loop)
 	      dim = info->dim[n];
 	      if (info->ref->u.ar.dimen_type[dim] != DIMEN_RANGE)
 		continue;
+	      if (n == info->ref->u.ar.dimen - 1
+		  && (info->ref->u.ar.as->type == AS_ASSUMED_SIZE
+		      || info->ref->u.ar.as->cp_was_assumed))
+		continue;
 
 	      desc = ss->data.info.descriptor;
 
-	      /* Check lower bound.  */
-	      bound = gfc_conv_array_lbound (desc, dim);
-	      tmp = info->start[n];
-	      tmp = fold_build2 (LT_EXPR, boolean_type_node, tmp, bound);
+	      /* This is the run-time equivalent of resolve.c's
+	         check_dimension().  The logical is more readable there
+	         than it is here, with all the trees.  */
+	      lbound = gfc_conv_array_lbound (desc, dim);
+	      ubound = gfc_conv_array_ubound (desc, dim);
+	      end = gfc_conv_section_upper_bound (ss, n, &block);
+
+	      /* Zero stride is not allowed.  */
+	      tmp = fold_build2 (EQ_EXPR, boolean_type_node, info->stride[n],
+				 gfc_index_zero_node);
+	      asprintf (&msg, "Zero stride is not allowed, for dimension %d "
+			"of array '%s'", info->dim[n]+1,
+			ss->expr->symtree->name);
+	      gfc_trans_runtime_check (tmp, msg, &block, &ss->expr->where);
+	      gfc_free (msg);
+
+	      /* non_zerosized is true when the selected range is not
+	         empty.  */
+	      stride_pos = fold_build2 (GT_EXPR, boolean_type_node,
+					info->stride[n], gfc_index_zero_node);
+	      tmp = fold_build2 (LE_EXPR, boolean_type_node, info->start[n],
+				 end);
+	      stride_pos = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+					stride_pos, tmp);
+
+	      stride_neg = fold_build2 (LT_EXPR, boolean_type_node,
+					info->stride[n], gfc_index_zero_node);
+	      tmp = fold_build2 (GE_EXPR, boolean_type_node, info->start[n],
+				 end);
+	      stride_neg = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+					stride_neg, tmp);
+	      non_zerosized = fold_build2 (TRUTH_OR_EXPR, boolean_type_node,
+					   stride_pos, stride_neg);
+
+	      /* Check the start of the range against the lower and upper
+		 bounds of the array, if the range is not empty.  */
+	      tmp = fold_build2 (LT_EXPR, boolean_type_node, info->start[n],
+				 lbound);
+	      tmp = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+				 non_zerosized, tmp);
 	      asprintf (&msg, "%s, lower bound of dimension %d of array '%s'"
-			" exceeded", gfc_msg_bounds, n+1,
+			" exceeded", gfc_msg_fault, info->dim[n]+1,
 			ss->expr->symtree->name);
 	      gfc_trans_runtime_check (tmp, msg, &block, &ss->expr->where);
 	      gfc_free (msg);
 
-	      /* Check the upper bound.  */
-	      bound = gfc_conv_array_ubound (desc, dim);
-	      end = gfc_conv_section_upper_bound (ss, n, &block);
-	      tmp = fold_build2 (GT_EXPR, boolean_type_node, end, bound);
+	      tmp = fold_build2 (GT_EXPR, boolean_type_node, info->start[n],
+				 ubound);
+	      tmp = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+				 non_zerosized, tmp);
+	      asprintf (&msg, "%s, upper bound of dimension %d of array '%s'"
+			" exceeded", gfc_msg_fault, info->dim[n]+1,
+			ss->expr->symtree->name);
+	      gfc_trans_runtime_check (tmp, msg, &block, &ss->expr->where);
+	      gfc_free (msg);
+
+	      /* Compute the last element of the range, which is not
+		 necessarily "end" (think 0:5:3, which doesn't contain 5)
+		 and check it against both lower and upper bounds.  */
+	      tmp2 = fold_build2 (MINUS_EXPR, gfc_array_index_type, end,
+				  info->start[n]);
+	      tmp2 = fold_build2 (TRUNC_MOD_EXPR, gfc_array_index_type, tmp2,
+				  info->stride[n]);
+	      tmp2 = fold_build2 (MINUS_EXPR, gfc_array_index_type, end,
+				  tmp2);
+
+	      tmp = fold_build2 (LT_EXPR, boolean_type_node, tmp2, lbound);
+	      tmp = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+				 non_zerosized, tmp);
+	      asprintf (&msg, "%s, lower bound of dimension %d of array '%s'"
+			" exceeded", gfc_msg_fault, info->dim[n]+1,
+			ss->expr->symtree->name);
+	      gfc_trans_runtime_check (tmp, msg, &block, &ss->expr->where);
+	      gfc_free (msg);
+
+	      tmp = fold_build2 (GT_EXPR, boolean_type_node, tmp2, ubound);
+	      tmp = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+				 non_zerosized, tmp);
 	      asprintf (&msg, "%s, upper bound of dimension %d of array '%s'"
-			" exceeded", gfc_msg_bounds, n+1,
+			" exceeded", gfc_msg_fault, info->dim[n]+1,
 			ss->expr->symtree->name);
 	      gfc_trans_runtime_check (tmp, msg, &block, &ss->expr->where);
 	      gfc_free (msg);
@@ -2586,7 +2655,7 @@ gfc_conv_ss_startstride (gfc_loopinfo * loop)
 		  tmp =
 		    fold_build2 (NE_EXPR, boolean_type_node, tmp, size[n]);
 		  asprintf (&msg, "%s, size mismatch for dimension %d "
-			    "of array '%s'", gfc_msg_bounds, n+1,
+			    "of array '%s'", gfc_msg_bounds, info->dim[n]+1,
 			    ss->expr->symtree->name);
 		  gfc_trans_runtime_check (tmp, msg, &block, &ss->expr->where);
 		  gfc_free (msg);