[PATCH v5 08/15] vla: support for DW_AT_count

[Sanimir Agovic <sanimir dot agovic at intel dot com>]

This patch adds support for DW_AT_count as requested in the code review:

  https://sourceware.org/ml/gdb-patches/2013-11/msg00200.html

2013-11-19  Sanimir Agovic  <sanimir.agovic@intel.com>
            Keven Boell <keven.boell@intel.com>

	* dwarf2read.c (read_subrange_type): Convert DW_AT_count to a dynamic
	property and store it as the high bound and flag the range accordingly.
	* gdbtypes.c (resolve_dynamic_bounds): If range is flagged as
	RANGE_UPPER_BOUND_IS_COUNT assign low + high - 1 as the new high bound.
	* gdbtypes.h (enum range_flags): New enum.
	(struct range_bounds): Add flags member.


Signed-off-by: Sanimir Agovic <sanimir.agovic@intel.com>
---
 gdb/dwarf2read.c | 18 ++++++++++--------
 gdb/gdbtypes.c   |  5 +++++
 gdb/gdbtypes.h   |  9 +++++++++
 3 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 1d5fa3d..1e4de21 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -14334,6 +14334,7 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
   struct attribute *attr;
   struct dynamic_prop low, high;
   int low_default_is_valid;
+  int high_bound_is_count = 0;
   const char *name;
   LONGEST negative_mask;
 
@@ -14400,15 +14401,13 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
   if (!attr_to_dynamic_prop (attr, die, cu, &high))
     {
       attr = dwarf2_attr (die, DW_AT_count, cu);
-      if (attr)
-	{
-	  int count = dwarf2_get_attr_constant_value (attr, 1);
-	  high.data.const_val = low.data.const_val + count - 1;
-	}
-      else
+      if (attr_to_dynamic_prop (attr, die, cu, &high))
 	{
-	  /* Unspecified array length.  */
-	  high.data.const_val = low.data.const_val - 1;
+	  /* If bounds are constant do the final calculation here.  */
+	  if (low.kind == PROP_CONST && high.kind == PROP_CONST)
+	    high.data.const_val = low.data.const_val + high.data.const_val - 1;
+	  else
+	    high_bound_is_count = 1;
 	}
     }
 
@@ -14461,6 +14460,9 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
 
   range_type = create_range_type (NULL, orig_base_type, &low, &high);
 
+  if (high_bound_is_count)
+    TYPE_RANGE_DATA (range_type)->flags = RANGE_UPPER_BOUND_IS_COUNT;
+
   /* Ada expects an empty array on no boundary attributes.  */
   if (attr == NULL && cu->language != language_ada)
     TYPE_HIGH_BOUND_KIND (range_type) = PROP_UNDEFINED;
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index f5bd236..83a2c75 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -1674,6 +1674,11 @@ resolve_dynamic_bounds (struct type *type, CORE_ADDR addr)
     {
       high_bound.kind = PROP_CONST;
       high_bound.data.const_val = value;
+
+      if ((TYPE_RANGE_DATA (range_type)->flags & RANGE_UPPER_BOUND_IS_COUNT)
+	  == RANGE_UPPER_BOUND_IS_COUNT)
+	high_bound.data.const_val
+	  = low_bound.data.const_val + high_bound.data.const_val - 1;
     }
   else
     {
diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
index 38cd240..100e3f4 100644
--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -392,6 +392,12 @@ struct dynamic_prop
   } data;
 };
 
+/* Flags used in main_type.range_bounds for bounds evaluation.  */
+
+enum range_flags
+{
+  RANGE_UPPER_BOUND_IS_COUNT = 1 /* High bound contains number of elements.  */
+};
 
 /* Determine which field of the union main_type.fields[x].loc is used.  */
 
@@ -622,6 +628,9 @@ struct main_type
       /* High bound of range.  */
 
       struct dynamic_prop high;
+
+      /* Flags about this range.  */
+      unsigned int flags;
     } *bounds;
 
   } flds_bnds;
-- 
1.8.4.2