RE: [ping] [PATCH v2 0/6] fortran: multi-dimensional subarrays with strides

https://sourceware.org/ml/gdb-patches/2016-07/msg00009.html

From 338e4c860ad205896b4a95c79f54470c79eeb348 Mon Sep 17 00:00:00 2001

From: Christoph Weinmann <christoph.t.weinmann@intel.com>

Date: Wed, 1 Jun 2016 15:11:24 +0200

Subject: [PATCH 4/6] fortran: enable parsing of stride parameter for subranges

Allow the user to provide a stride parameter for Fortran

subarrays.  The stride parameter can be any integer except

'0'.  The default stride value is '1'.

2013-11-27  Christoph Weinmann  <christoph.t.weinmann@intel.com>

	* eval.c (value_f90_subarray): Add expression evaluation

	for a stride parameter in a Fortran range expression.

	* expression.h (range_type): Add field to enum to show when

	a stride value was provided by the user.

	* f-exp.y: Add yacc rules for writing info on the elt stack

	when the user provided a stride argument.

	* parse.c (operator_length_standard): Check if a stride

	value was provided, and increment argument counter

	accordingly.

Signed-off-by: Christoph Weinmann <christoph.t.weinmann@intel.com>

---

 gdb/eval.c       | 11 ++++++++++-

 gdb/expression.h |  7 +++++--

 gdb/f-exp.y      | 31 ++++++++++++++++++++++++++++++-

 gdb/parse.c      |  3 +++

 gdb/valops.c     |  4 ++--

 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/gdb/eval.c b/gdb/eval.c

index 44e8600..b5aaf1c 100644

--- a/gdb/eval.c

+++ b/gdb/eval.c

@@ -419,7 +419,7 @@ value_f90_subarray (struct value *array, struct expression *exp,

   typedef struct subscript_range

   {

     enum range_type f90_range_type;

-    LONGEST low, high;

+    LONGEST low, high, stride;

   } subscript_range;

   typedef enum subscript_kind

@@ -490,6 +490,15 @@ value_f90_subarray (struct value *array, struct expression *exp,

 	      == SUBARRAY_HIGH_BOUND)

 	    range->high = value_as_long (evaluate_subexp (NULL_TYPE, exp,

 							  pos, noside));

+

+	  /* Assign the user's stride value if provided.  */

+	  if ((range->f90_range_type & SUBARRAY_STRIDE) == SUBARRAY_STRIDE)

+	    range->stride = value_as_long (evaluate_subexp (NULL_TYPE, exp,

+							     pos, noside));

+

+	  /* Assign the default stride value '1'.  */

+	  else

+	    range->stride = 1;

 	}

       /* User input is an index.  E.g.: "p arry(5)".  */

       else

diff --git a/gdb/expression.h b/gdb/expression.h

index 5a6b720..34ca54b 100644

--- a/gdb/expression.h

+++ b/gdb/expression.h

@@ -153,13 +153,16 @@ extern void dump_raw_expression (struct expression *,

 extern void dump_prefix_expression (struct expression *, struct ui_file *);

 /* In an OP_RANGE expression, either bound can be provided by the user, or not.

-   This enumeration type is to identify this.  */

+   In addition to this, the user can also specify a stride value to indicated

+   only certain elements of the array.  This enumeration type is to identify

+   this.  */

 enum range_type

   {

     SUBARRAY_NONE_BOUND = 0x0,		/* "( : )"  */

     SUBARRAY_LOW_BOUND = 0x1,		/* "(low:)"  */

-    SUBARRAY_HIGH_BOUND = 0x2		/* "(:high)"  */

+    SUBARRAY_HIGH_BOUND = 0x2,		/* "(:high)"  */

+    SUBARRAY_STRIDE = 0x4		/* "(::stride)"  */

   };

 #endif /* !defined (EXPRESSION_H) */

diff --git a/gdb/f-exp.y b/gdb/f-exp.y

index e2c54b6..71f1823 100644

--- a/gdb/f-exp.y

+++ b/gdb/f-exp.y

@@ -280,7 +280,36 @@ subrange:	':' exp	%prec ABOVE_COMMA

 subrange:	':'	%prec ABOVE_COMMA

 			{ write_exp_elt_opcode (pstate, OP_RANGE);

-			  write_exp_elt_longcst (pstate, 0);

+			  write_exp_elt_longcst (pstate, SUBARRAY_NONE_BOUND);

+			  write_exp_elt_opcode (pstate, OP_RANGE); }

+	;

+

+/* Each subrange type can have a stride argument.  */

+subrange:	exp ':' exp ':' exp %prec ABOVE_COMMA

+			{ write_exp_elt_opcode (pstate, OP_RANGE);

+			  write_exp_elt_longcst (pstate, SUBARRAY_LOW_BOUND

+						 | SUBARRAY_HIGH_BOUND

+						 | SUBARRAY_STRIDE);

+			  write_exp_elt_opcode (pstate, OP_RANGE); }

+	;

+

+subrange:	exp ':' ':' exp %prec ABOVE_COMMA

+			{ write_exp_elt_opcode (pstate, OP_RANGE);

+			  write_exp_elt_longcst (pstate, SUBARRAY_LOW_BOUND

+						 | SUBARRAY_STRIDE);

+			  write_exp_elt_opcode (pstate, OP_RANGE); }

+	;

+

+subrange:	':' exp ':' exp %prec ABOVE_COMMA

+			{ write_exp_elt_opcode (pstate, OP_RANGE);

+			  write_exp_elt_longcst (pstate, SUBARRAY_HIGH_BOUND

+						 | SUBARRAY_STRIDE);

+			  write_exp_elt_opcode (pstate, OP_RANGE); }

+	;

+

+subrange:	':' ':' exp %prec ABOVE_COMMA

+			{ write_exp_elt_opcode (pstate, OP_RANGE);

+			  write_exp_elt_longcst (pstate, SUBARRAY_STRIDE);

 			  write_exp_elt_opcode (pstate, OP_RANGE); }

 	;

diff --git a/gdb/parse.c b/gdb/parse.c

index 6d54a77..992af87 100644

--- a/gdb/parse.c

+++ b/gdb/parse.c

@@ -1018,6 +1018,9 @@ operator_length_standard (const struct expression *expr, int endpos,

       if ((range_type & SUBARRAY_HIGH_BOUND) == SUBARRAY_HIGH_BOUND)

 	args++;

+      if ((range_type & SUBARRAY_STRIDE) == SUBARRAY_STRIDE)

+	args++;

+

       break;

     default:

diff --git a/gdb/valops.c b/gdb/valops.c

index 817a4cf..fbc7dcb 100644

--- a/gdb/valops.c

+++ b/gdb/valops.c

@@ -3834,7 +3834,7 @@ value_slice_1 (struct value *array, int lowbound, int length, int call_count)

   if (call_count == 1)

     {

       range_type = TYPE_INDEX_TYPE (array_type);

-      slice_range_size = elem_count;

+      slice_range_size = ary_low_bound + elem_count - 1;

       /* Check if the array bounds are valid.  */

       if (get_discrete_bounds (range_type, &ary_low_bound, &ary_high_bound) < 0)

@@ -3846,7 +3846,7 @@ value_slice_1 (struct value *array, int lowbound, int length, int call_count)

   else

     {

       range_type = TYPE_INDEX_TYPE (TYPE_TARGET_TYPE (array_type));

-      slice_range_size = (ary_low_bound + row_count - 1) * (elem_count);

+      slice_range_size = ary_low_bound + (row_count * elem_count) - 1;

       ary_low_bound = TYPE_LOW_BOUND (range_type);

     }

-- 

2.5.5