[PATCH v3 02/13] type: add c99 variable length array support

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

The dwarf standard allow certain attributes to be expressed as dwarf
expressions rather than constants. For instance upper-/lowerbound attributes.
In case of a c99 variable length array the upperbound is a dynamic attribute.

With this change c99 vla behave the same as with static arrays.

1| void foo (size_t n) {
2|   int ary[n];
3|   memset(ary, 0, sizeof(ary));
4| }

(gdb) print ary
$1 = {0 <repeats 42 times>}

2013-10-18  Sanimir Agovic  <sanimir.agovic@intel.com>
            Keven Boell  <keven.boell@intel.com>

	* dwarf2loc.c (dwarf2_locexpr_baton_eval): New function.
	(dwarf2_evaluate_property): New function.
	* dwarf2loc.h (dwarf2_evaluate_property): New function prototype.
	* dwarf2read.c (block_to_locexprbaton): New function.
	(attr_to_dynamic_prop): New function.
	(read_subrange_type): Use attr_to_dynamic_prop to read high bound
	attribute.
	* gdbtypes.c: Include dwarf2loc.h.
	(is_dynamic_type): New function.
	(resolve_dynamic_type): New function.
	(resolve_dynamic_bounds): New function.
	(get_type_length): New function.
	(check_typedef): Use get_type_length to compute type length.
	* gdbtypes.h (TYPE_HIGH_BOUND_KIND): New macro.
	(TYPE_LOW_BOUND_KIND): New macro.
	(is_dynamic_type): New function prototype.

Change-Id: I59036232c0b93e79427bf34041b3bbf8992e731a
Signed-off-by: Sanimir Agovic <sanimir.agovic@intel.com>
---
 gdb/dwarf2loc.c  | 105 +++++++++++++++++++++++
 gdb/dwarf2loc.h  |  26 ++++++
 gdb/dwarf2read.c | 132 +++++++++++++++++++++++------
 gdb/gdbtypes.c   | 248 +++++++++++++++++++++++++++++++++++++++++++------------
 gdb/gdbtypes.h   |  10 +++
 gdb/value.c      |  11 ++-
 6 files changed, 449 insertions(+), 83 deletions(-)

diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c
index 2d15546..9fcfe21 100644
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -2430,6 +2430,111 @@ dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame,
   return dwarf2_evaluate_loc_desc_full (type, frame, data, size, per_cu, 0);
 }
 
+/* Evaluates a dwarf expression and stores the result in VAL, expecting
+   that the dwarf expression only produces a single CORE_ADDR.  ADDR is a
+   context (location of a variable) and might be needed to evaluate the
+   location expression.
+   Returns 1 on success, 0 otherwise.   */
+
+static int
+dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
+			   CORE_ADDR addr, CORE_ADDR *valp)
+{
+  struct dwarf_expr_context *ctx;
+  struct dwarf_expr_baton baton;
+  struct objfile *objfile;
+  struct cleanup *cleanup;
+
+  if (dlbaton == NULL || dlbaton->size == 0)
+    return 0;
+
+  ctx = new_dwarf_expr_context ();
+  cleanup = make_cleanup_free_dwarf_expr_context (ctx);
+
+  baton.frame = get_selected_frame (NULL);
+  baton.per_cu = dlbaton->per_cu;
+
+  objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
+
+  ctx->gdbarch = get_objfile_arch (objfile);
+  ctx->addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
+  ctx->ref_addr_size = dwarf2_per_cu_ref_addr_size (dlbaton->per_cu);
+  ctx->offset = dwarf2_per_cu_text_offset (dlbaton->per_cu);
+  ctx->funcs = &dwarf_expr_ctx_funcs;
+  ctx->baton = &baton;
+
+  dwarf_expr_eval (ctx, dlbaton->data, dlbaton->size);
+
+  switch (ctx->location)
+    {
+    case DWARF_VALUE_REGISTER:
+    case DWARF_VALUE_MEMORY:
+    case DWARF_VALUE_STACK:
+      *valp = dwarf_expr_fetch_address (ctx, 0);
+      if (ctx->location == DWARF_VALUE_REGISTER)
+	*valp = dwarf_expr_read_addr_from_reg (&baton, *valp);
+      do_cleanups (cleanup);
+      return 1;
+    case DWARF_VALUE_LITERAL:
+      *valp = extract_signed_integer (ctx->data, ctx->len,
+				      gdbarch_byte_order (ctx->gdbarch));
+      do_cleanups (cleanup);
+      return 1;
+      /* Not supported dwarf values.  */
+    case DWARF_VALUE_OPTIMIZED_OUT:
+    case DWARF_VALUE_IMPLICIT_POINTER:
+      break;
+    }
+
+  do_cleanups (cleanup);
+
+  return 0;
+}
+
+/* See dwarf2loc.h.  */
+
+int
+dwarf2_evaluate_property (const struct dynamic_prop *prop, CORE_ADDR address,
+			  CORE_ADDR *value)
+{
+  if (prop == NULL)
+    return 0;
+
+  switch (prop->kind)
+    {
+    case PROP_LOCEXPR:
+      {
+	const struct dwarf2_property_baton *baton = prop->data.baton;
+
+	return dwarf2_locexpr_baton_eval (&baton->locexpr, address, value);
+      }
+    case PROP_LOCLIST:
+      {
+	struct dwarf2_property_baton *baton = prop->data.baton;
+	struct frame_info *frame = get_selected_frame (NULL);
+	CORE_ADDR pc = get_frame_address_in_block (frame);
+	const gdb_byte *data;
+	struct value *val;
+	size_t size;
+
+	data = dwarf2_find_location_expression (&baton->loc.list, &size, pc);
+	if (data != NULL)
+	  {
+	    val = dwarf2_evaluate_loc_desc (baton->loc.type, frame, data,
+					    size, baton->loc.list.per_cu);
+	    if (!value_optimized_out (val))
+	      *value = value_as_long (value_ind (val));
+	  }
+	return 1;
+      }
+    case PROP_CONST:
+      *value = prop->data.const_val;
+      return 1;
+    }
+
+  return 0;
+}
+
 
 /* Helper functions and baton for dwarf2_loc_desc_needs_frame.  */
 
diff --git a/gdb/dwarf2loc.h b/gdb/dwarf2loc.h
index 9bc8ca5..2155fe1 100644
--- a/gdb/dwarf2loc.h
+++ b/gdb/dwarf2loc.h
@@ -90,6 +90,13 @@ struct value *dwarf2_evaluate_loc_desc (struct type *type,
 					size_t size,
 					struct dwarf2_per_cu_data *per_cu);
 
+/* Converts a dynamic property into a static one.  ADDR is the address of
+   the object currently being evaluated and might be nedded.
+   Returns 1 if PROP could be converted and the static value is passed back
+   into VALUE, otherwise returns 0.  */
+int dwarf2_evaluate_property (const struct dynamic_prop *prop,
+			      CORE_ADDR addr, CORE_ADDR *value);
+
 CORE_ADDR dwarf2_read_addr_index (struct dwarf2_per_cu_data *per_cu,
 				  unsigned int addr_index);
 
@@ -135,6 +142,25 @@ struct dwarf2_loclist_baton
   unsigned char from_dwo;
 };
 
+/* A dynamic property is either expressed as a single location expression
+   or a location list in the context of TYPE.  */
+
+struct dwarf2_property_baton
+{
+  union
+  {
+    /* Location expression.  */
+    struct dwarf2_locexpr_baton locexpr;
+
+    /* Location list to be evaluated in the context of TYPE.  */
+    struct
+    {
+      struct dwarf2_loclist_baton list;
+      struct type *type;
+    } loc;
+  };
+};
+
 extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
 extern const struct symbol_computed_ops dwarf2_loclist_funcs;
 
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 6bdd45a..0df385a 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -14252,6 +14252,110 @@ read_base_type (struct die_info *die, struct dwarf2_cu *cu)
   return set_die_type (die, type, cu);
 }
 
+/* Turn Dwarf block into location expression baton structure. Used to store
+   baton into "dynamic" types, e.g. VLA's.  Specifing ADDITIONAL_DATA and
+   EXTRA_SIZE allows to append additional opcodes to the dwarf expression.  */
+
+static struct dwarf2_locexpr_baton
+block_to_locexpr_baton (const struct dwarf_block *blk, struct dwarf2_cu *cu,
+			const gdb_byte *additional_data, int extra_size)
+{
+  struct dwarf2_locexpr_baton baton;
+
+  gdb_assert (blk != NULL);
+
+  baton.per_cu = cu->per_cu;
+  baton.size = blk->size + extra_size;
+
+  if (additional_data != NULL && extra_size > 0)
+    {
+      gdb_byte *data;
+
+      data = obstack_alloc (&cu->objfile->objfile_obstack, baton.size);
+      baton.data = data;
+
+      memcpy (data, blk->data, blk->size);
+      memcpy (data + blk->size, additional_data, extra_size);
+    }
+  else
+    /* Copy the data pointer as the block's lifetime is bound to its
+       object file. */
+    baton.data = blk->data;
+
+  gdb_assert (baton.data != NULL);
+
+  return baton;
+}
+
+/* Parse dwarf attribute if it's a block, reference or constant and put the
+   resulting value of the attribute into struct bound_prop.
+   Returns 1 if ATTR could be resolved into PROP, 0 otherwise.  */
+
+static int
+attr_to_dynamic_prop (const struct attribute *attr, struct die_info *die,
+		      struct dwarf2_cu *cu, struct dynamic_prop *prop)
+{
+  struct dwarf2_property_baton *baton;
+  struct obstack *obstack = &cu->objfile->objfile_obstack;
+
+  if (attr == NULL || prop == NULL)
+    return 0;
+
+  if (attr_form_is_block (attr))
+    {
+      baton = obstack_alloc (obstack, sizeof (*baton));
+      baton->locexpr = block_to_locexpr_baton (DW_BLOCK (attr), cu, NULL, 0);
+      prop->data.baton = baton;
+      prop->kind = PROP_LOCEXPR;
+      gdb_assert (prop->data.baton != NULL);
+    }
+  else if (attr_form_is_ref (attr))
+    {
+      struct dwarf2_cu *target_cu = cu;
+      struct die_info *target_die;
+      struct attribute *target_attr;
+
+      target_die = follow_die_ref (die, attr, &target_cu);
+      target_attr = dwarf2_attr (target_die, DW_AT_location, target_cu);
+      if (target_attr == NULL)
+	return 0;
+
+      if (attr_form_is_section_offset (target_attr))
+	{
+	  baton = obstack_alloc (obstack, sizeof (*baton));
+	  baton->loc.type = die_type (target_die, target_cu);;
+	  fill_in_loclist_baton (cu, &baton->loc.list, target_attr);
+	  prop->data.baton = baton;
+	  prop->kind = PROP_LOCLIST;
+	  gdb_assert (prop->data.baton != NULL);
+	}
+      else if (attr_form_is_block (target_attr))
+	{
+	  const gdb_byte ops[] = {DW_OP_deref};
+
+	  baton = obstack_alloc (obstack, sizeof (*baton));
+	  baton->locexpr = block_to_locexpr_baton (DW_BLOCK (target_attr),
+						   cu, ops, sizeof (ops));
+	  prop->data.baton = baton;
+	  prop->kind = PROP_LOCEXPR;
+	  gdb_assert (prop->data.baton != NULL);
+	}
+    }
+  else if (attr_form_is_constant (attr))
+    {
+      prop->data.const_val = dwarf2_get_attr_constant_value (attr, 0);
+      prop->kind = PROP_CONST;
+    }
+  else
+    {
+      dwarf2_invalid_attrib_class_complaint (dwarf_form_name (attr->form),
+					     dwarf2_name (die, cu));
+      return 0;
+    }
+
+  return 1;
+}
+
 /* Read the given DW_AT_subrange DIE.  */
 
 static struct type *
@@ -14325,27 +14429,7 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
 	       die->offset.sect_off, objfile_name (cu->objfile));
 
   attr = dwarf2_attr (die, DW_AT_upper_bound, cu);
-  if (attr)
-    {
-      if (attr_form_is_block (attr) || attr_form_is_ref (attr))
-        {
-          /* GCC encodes arrays with unspecified or dynamic length
-             with a DW_FORM_block1 attribute or a reference attribute.
-             FIXME: GDB does not yet know how to handle dynamic
-             arrays properly, treat them as arrays with unspecified
-             length for now.
-
-             FIXME: jimb/2003-09-22: GDB does not really know
-             how to handle arrays of unspecified length
-             either; we just represent them as zero-length
-             arrays.  Choose an appropriate upper bound given
-             the lower bound we've computed above.  */
-          high.data.const_val = low.data.const_val - 1;
-        }
-      else
-        high.data.const_val = dwarf2_get_attr_constant_value (attr, 1);
-    }
-  else
+  if (!attr_to_dynamic_prop (attr, die, cu, &high))
     {
       attr = dwarf2_attr (die, DW_AT_count, cu);
       if (attr)
@@ -14409,12 +14493,6 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
 
   range_type = create_range_type_1 (NULL, orig_base_type, &low, &high);
 
-  /* Mark arrays with dynamic length at least as an array of unspecified
-     length.  GDB could check the boundary but before it gets implemented at
-     least allow accessing the array elements.  */
-  if (attr && attr_form_is_block (attr))
-    TYPE_HIGH_BOUND_KIND (range_type) = PROP_UNDEFINED;
-
   /* 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 276ebe3..59aaf3d 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -1,5 +1,6 @@
 /* Support routines for manipulating internal types for GDB.
 
+
    Copyright (C) 1992-2013 Free Software Foundation, Inc.
 
    Contributed by Cygnus Support, using pieces from other GDB modules.
@@ -38,6 +39,7 @@
 #include "hashtab.h"
 #include "exceptions.h"
 #include "cp-support.h"
+#include "dwarf2loc.h"
 
 /* Initialize BADNESS constants.  */
 
@@ -852,6 +854,17 @@ create_range_type (struct type *result_type, struct type *index_type,
   return result_type;
 }
 
+/* Predicate tests whether BOUNDS are static.  Returns 1 if all bounds values
+   are static, otherwise returns 0.  */
+
+static int
+has_static_range (const struct range_bounds *bounds)
+{
+  return (bounds->low.kind == PROP_CONST
+	  && bounds->high.kind == PROP_CONST);
+}
+
+
 /* Set *LOWP and *HIGHP to the lower and upper bounds of discrete type
    TYPE.  Return 1 if type is a range type, 0 if it is discrete (and
    bounds will fit in LONGEST), or -1 otherwise.  */
@@ -981,24 +994,28 @@ create_array_type (struct type *result_type,
 		   struct type *element_type,
 		   struct type *range_type)
 {
-  LONGEST low_bound, high_bound;
-
   if (result_type == NULL)
     result_type = alloc_type_copy (range_type);
 
   TYPE_CODE (result_type) = TYPE_CODE_ARRAY;
   TYPE_TARGET_TYPE (result_type) = element_type;
-  if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
-    low_bound = high_bound = 0;
-  CHECK_TYPEDEF (element_type);
-  /* Be careful when setting the array length.  Ada arrays can be
-     empty arrays with the high_bound being smaller than the low_bound.
-     In such cases, the array length should be zero.  */
-  if (high_bound < low_bound)
-    TYPE_LENGTH (result_type) = 0;
-  else
-    TYPE_LENGTH (result_type) =
-      TYPE_LENGTH (element_type) * (high_bound - low_bound + 1);
+
+  if (has_static_range (TYPE_RANGE_DATA (range_type)))
+    {
+      LONGEST low_bound, high_bound;
+
+      if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
+	low_bound = high_bound = 0;
+      CHECK_TYPEDEF (element_type);
+      /* Be careful when setting the array length.  Ada arrays can be
+	 empty arrays with the high_bound being smaller than the low_bound.
+	 In such cases, the array length should be zero.  */
+      if (high_bound < low_bound)
+	TYPE_LENGTH (result_type) = 0;
+      else
+	TYPE_LENGTH (result_type) =
+	  TYPE_LENGTH (element_type) * (high_bound - low_bound + 1);
+    }
   TYPE_NFIELDS (result_type) = 1;
   TYPE_FIELDS (result_type) =
     (struct field *) TYPE_ZALLOC (result_type, sizeof (struct field));
@@ -1529,7 +1546,163 @@ stub_noname_complaint (void)
   complaint (&symfile_complaints, _("stub type has NULL name"));
 }
 
-/* Find the real type of TYPE.  This function returns the real type,
+/* Calculates the size of a type.  If TYPE has static bound values takes upper
+   and lower bound into account, otherwise only the TYPE length is returned.
+   TYPE is expected not to be a typedef.  */
+
+static ULONGEST
+get_type_length (const struct type *type)
+{
+  const struct type *range_type, *target_type;
+  ULONGEST len = TYPE_LENGTH (type);
+  LONGEST low_bound, high_bound;
+
+  gdb_assert (TYPE_CODE (type) != TYPE_CODE_TYPEDEF);
+
+  if (TYPE_CODE (type) != TYPE_CODE_ARRAY
+      && TYPE_CODE (type) != TYPE_CODE_STRING)
+    return len;
+
+  range_type = check_typedef (TYPE_INDEX_TYPE (type));
+
+  if (!has_static_range (TYPE_RANGE_DATA (range_type)))
+    return len;
+
+  target_type = check_typedef (TYPE_TARGET_TYPE (type));
+
+  /* Now recompute the length of the array type, based on its
+     number of elements and the target type's length.
+     Watch out for Ada null Ada arrays where the high bound
+     is smaller than the low bound.  */
+  low_bound = TYPE_LOW_BOUND (range_type);
+  high_bound = TYPE_HIGH_BOUND (range_type);
+
+  if (high_bound < low_bound)
+    len = 0;
+  else
+    {
+      /* For now, we conservatively take the array length to be 0
+         if its length exceeds UINT_MAX.  The code below assumes
+         that for x < 0, (ULONGEST) x == -x + ULONGEST_MAX + 1,
+         which is technically not guaranteed by C, but is usually true
+         (because it would be true if x were unsigned with its
+         high-order bit on).  It uses the fact that
+         high_bound-low_bound is always representable in
+         ULONGEST and that if high_bound-low_bound+1 overflows,
+         it overflows to 0.  We must change these tests if we
+         decide to increase the representation of TYPE_LENGTH
+         from unsigned int to ULONGEST.  */
+      ULONGEST ulow = low_bound, uhigh = high_bound;
+      ULONGEST tlen = get_type_length (target_type);
+
+      len = tlen * (uhigh - ulow + 1);
+      if (tlen == 0 || (len / tlen - 1 + ulow) != uhigh || len > UINT_MAX)
+        len = 0;
+    }
+
+  return len;
+}
+
+/* See gdbtypes.h.  */
+
+int
+is_dynamic_type (const struct type *type)
+{
+  if (TYPE_CODE (type) == TYPE_CODE_ARRAY
+      && TYPE_NFIELDS (type) == 1)
+    {
+      const struct type *range_type = TYPE_INDEX_TYPE (type);
+
+      if (!has_static_range (TYPE_RANGE_DATA (range_type)))
+	return 1;
+    }
+
+  if (TYPE_CODE (type) == TYPE_CODE_PTR
+      || TYPE_CODE (type) == TYPE_CODE_REF
+      || TYPE_CODE (type) == TYPE_CODE_TYPEDEF)
+    return is_dynamic_type (TYPE_TARGET_TYPE (type));
+
+  return 0;
+}
+
+/* Resolves dynamic bound values of an array type to static ones.
+   TYPE is modified in place and is expected not to be a typedef.
+   ADDRESS might be needed to resolve the subrange bounds, it is the location
+   of the associated array.  */
+
+static void
+resolve_dynamic_bounds (struct type *type, CORE_ADDR address)
+{
+  struct type *real_type;
+  const struct dynamic_prop *prop;
+  CORE_ADDR value;
+
+  gdb_assert (TYPE_CODE (type) != TYPE_CODE_TYPEDEF);
+
+  if (TYPE_CODE (type) == TYPE_CODE_PTR
+      || TYPE_CODE (type) == TYPE_CODE_REF)
+    resolve_dynamic_bounds (check_typedef (TYPE_TARGET_TYPE (type)), address);
+  else
+    {
+      if (TYPE_CODE (type) == TYPE_CODE_ARRAY)
+	{
+	  struct type *ary_dim = type;
+
+	  do {
+	    struct type *range_type = check_typedef (TYPE_INDEX_TYPE (ary_dim));
+
+	    prop = &TYPE_RANGE_DATA (range_type)->low;
+	    if (dwarf2_evaluate_property (prop, address, &value))
+	      {
+		TYPE_LOW_BOUND (range_type) = value;
+		TYPE_LOW_BOUND_KIND (range_type) = PROP_CONST;
+	      }
+
+	    prop = &TYPE_RANGE_DATA (range_type)->high;
+	    if (dwarf2_evaluate_property (prop, address, &value))
+	      {
+		TYPE_HIGH_BOUND (range_type) = value;
+		TYPE_HIGH_BOUND_KIND (range_type) = PROP_CONST;
+	      }
+
+	    ary_dim = check_typedef (TYPE_TARGET_TYPE (ary_dim));
+	  } while (ary_dim != NULL && TYPE_CODE (ary_dim) == TYPE_CODE_ARRAY);
+	}
+    }
+}
+
+/* See gdbtypes.h  */
+
+struct type *
+resolve_dynamic_type (struct type *type, CORE_ADDR addr)
+{
+  struct type *real_type = check_typedef (type);
+  struct type *resolved_type;
+  struct cleanup *cleanup;
+  htab_t copied_types;
+
+  if (!TYPE_OBJFILE_OWNED (real_type))
+    return type;
+
+  if (!is_dynamic_type (real_type))
+    return type;
+
+  /* Make a deep copy of the type.  */
+  copied_types = create_copied_types_hash (TYPE_OBJFILE (type));
+  cleanup = make_cleanup_htab_delete (copied_types);
+  resolved_type = copy_type_recursive
+    (TYPE_OBJFILE (type), type, copied_types);
+  do_cleanups (cleanup);
+
+  real_type = check_typedef (resolved_type);
+  resolve_dynamic_bounds (real_type, addr);
+
+  resolved_type->length = get_type_length (real_type);
+
+  return resolved_type;
+}
+
+/* find the real type of TYPE.  This function returns the real type,
    after removing all layers of typedefs, and completing opaque or stub
    types.  Completion changes the TYPE argument, but stripping of
    typedefs does not.
@@ -1705,44 +1878,15 @@ check_typedef (struct type *type)
 	  /* Nothing we can do.  */
 	}
       else if (TYPE_CODE (type) == TYPE_CODE_ARRAY
-	       && TYPE_NFIELDS (type) == 1
-	       && (TYPE_CODE (range_type = TYPE_INDEX_TYPE (type))
-		   == TYPE_CODE_RANGE))
-	{
-	  /* Now recompute the length of the array type, based on its
-	     number of elements and the target type's length.
-	     Watch out for Ada null Ada arrays where the high bound
-	     is smaller than the low bound.  */
-	  const LONGEST low_bound = TYPE_LOW_BOUND (range_type);
-	  const LONGEST high_bound = TYPE_HIGH_BOUND (range_type);
-	  ULONGEST len;
-
-	  if (high_bound < low_bound)
-	    len = 0;
-	  else
-	    {
-	      /* For now, we conservatively take the array length to be 0
-		 if its length exceeds UINT_MAX.  The code below assumes
-		 that for x < 0, (ULONGEST) x == -x + ULONGEST_MAX + 1,
-		 which is technically not guaranteed by C, but is usually true
-		 (because it would be true if x were unsigned with its
-		 high-order bit on).  It uses the fact that
-		 high_bound-low_bound is always representable in
-		 ULONGEST and that if high_bound-low_bound+1 overflows,
-		 it overflows to 0.  We must change these tests if we 
-		 decide to increase the representation of TYPE_LENGTH
-		 from unsigned int to ULONGEST.  */
-	      ULONGEST ulow = low_bound, uhigh = high_bound;
-	      ULONGEST tlen = TYPE_LENGTH (target_type);
-
-	      len = tlen * (uhigh - ulow + 1);
-	      if (tlen == 0 || (len / tlen - 1 + ulow) != uhigh 
-		  || len > UINT_MAX)
-		len = 0;
-	    }
-	  TYPE_LENGTH (type) = len;
-	  TYPE_TARGET_STUB (type) = 0;
-	}
+	       || TYPE_CODE (type) == TYPE_CODE_STRING)
+        {
+          range_type = TYPE_INDEX_TYPE (type);
+          if (has_static_range (TYPE_RANGE_DATA (range_type)))
+            {
+              TYPE_LENGTH (type) = get_type_length (type);
+              TYPE_TARGET_STUB (type) = 0;
+            }
+        }
       else if (TYPE_CODE (type) == TYPE_CODE_RANGE)
 	{
 	  TYPE_LENGTH (type) = TYPE_LENGTH (target_type);
diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
index 4fa9ef5..3309ff7 100644
--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -1,3 +1,4 @@
+
 /* Internal type definitions for GDB.
 
    Copyright (C) 1992-2013 Free Software Foundation, Inc.
@@ -1570,6 +1571,15 @@ extern struct type *lookup_unsigned_typename (const struct language_defn *,
 extern struct type *lookup_signed_typename (const struct language_defn *,
 					    struct gdbarch *, const char *);
 
+/* Resolves all dynamic values of a type e.g. array bounds to static values.
+   ADDR specifies the location of the variable the type is bound to.
+   If TYPE has no dynamic values returns TYPE otherwise a new type with static
+   values is returned.  */
+extern struct type *resolve_dynamic_type (struct type *type, CORE_ADDR addr);
+
+/* Predicates if the type has dynamic values, which are not resolved yet.  */
+extern int is_dynamic_type (const struct type *type);
+
 extern struct type *check_typedef (struct type *);
 
 #define CHECK_TYPEDEF(TYPE)			\
diff --git a/gdb/value.c b/gdb/value.c
index 8c263ea..57b7696 100644
--- a/gdb/value.c
+++ b/gdb/value.c
@@ -3182,9 +3182,11 @@ value_from_ulongest (struct type *type, ULONGEST num)
 struct value *
 value_from_pointer (struct type *type, CORE_ADDR addr)
 {
-  struct value *val = allocate_value (type);
+  struct type *resolved_type = resolve_dynamic_type (type, addr);
+  struct value *val = allocate_value (resolved_type);
 
-  store_typed_address (value_contents_raw (val), check_typedef (type), addr);
+  store_typed_address (value_contents_raw (val),
+		       check_typedef (resolved_type), addr);
   return val;
 }
 
@@ -3198,12 +3200,13 @@ value_from_contents_and_address (struct type *type,
 				 const gdb_byte *valaddr,
 				 CORE_ADDR address)
 {
+  struct type *resolved_type = resolve_dynamic_type (type, address);
   struct value *v;
 
   if (valaddr == NULL)
-    v = allocate_value_lazy (type);
+    v = allocate_value_lazy (resolved_type);
   else
-    v = value_from_contents (type, valaddr);
+    v = value_from_contents (resolved_type, valaddr);
   set_value_address (v, address);
   VALUE_LVAL (v) = lval_memory;
   return v;
-- 
1.8.3.1