[PATCH 01/10] vla: introduce new bound type abstraction adapt uses

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

The rational behind this patch is to get started to implement the feature
described in dwarf4 standard (2.19) Static and Dynamic Values of Attributes.
It adds new DWARF2_PROP to store either a constant, exprloc, or reference to
describe an upper-/lower bound of a subrange. Other than that no new features
are introduce.

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

	* dwarf2read.c (read_subrange_type): Use struct dwarf2_prop for
	declaring high/low bounds and change uses accordingly. Call
	create_range_type_1 instead of create_range_type,
	* gdbtypes.c (create_range_type_1): New function.
	(create_range_type): Convert bounds into struct dwarf2_prop and pass
	them to create_range_type_1.
	* gdbtypes.h (struct dwarf2_prop): New struct.
	(create_range_type_1): New function prototype.
	(struct range_bounds): Use struct dwarf2_prop instead of LONGEST for
	high/low bounds.
	(TYPE_LOW_BOUND,TYPE_HIGH_BOUND): Adapt macros to refer to the static
	part of the bound.

Change-Id: I04ccd6b9bbf7519b99e814e9ee7119dbcd1f7baa
---
 gdb/dwarf2read.c |   40 +++++++++++++++++++++++-----------------
 gdb/gdbtypes.c   |   43 +++++++++++++++++++++++++++++++------------
 gdb/gdbtypes.h   |   38 ++++++++++++++++++++++++++++++++++----
 3 files changed, 88 insertions(+), 33 deletions(-)

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 3974d0b..36ed9bd 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -14142,7 +14142,7 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
   struct type *base_type, *orig_base_type;
   struct type *range_type;
   struct attribute *attr;
-  LONGEST low, high;
+  struct dwarf2_prop low, high;
   int low_default_is_valid;
   const char *name;
   LONGEST negative_mask;
@@ -14159,33 +14159,37 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
   if (range_type)
     return range_type;
 
+  low.kind = DWARF_CONST;
+  high.kind = DWARF_CONST;
+  high.data.const_val = 0;
+
   /* Set LOW_DEFAULT_IS_VALID if current language and DWARF version allow
      omitting DW_AT_lower_bound.  */
   switch (cu->language)
     {
     case language_c:
     case language_cplus:
-      low = 0;
+      low.data.const_val = 0;
       low_default_is_valid = 1;
       break;
     case language_fortran:
-      low = 1;
+      low.data.const_val = 1;
       low_default_is_valid = 1;
       break;
     case language_d:
     case language_java:
     case language_objc:
-      low = 0;
+      low.data.const_val = 0;
       low_default_is_valid = (cu->header.version >= 4);
       break;
     case language_ada:
     case language_m2:
     case language_pascal:
-      low = 1;
+      low.data.const_val = 1;
       low_default_is_valid = (cu->header.version >= 4);
       break;
     default:
-      low = 0;
+      low.data.const_val = 0;
       low_default_is_valid = 0;
       break;
     }
@@ -14195,7 +14199,7 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
      but we don't know how to handle it.  */
   attr = dwarf2_attr (die, DW_AT_lower_bound, cu);
   if (attr)
-    low = dwarf2_get_attr_constant_value (attr, low);
+    low.data.const_val = dwarf2_get_attr_constant_value (attr, low.data.const_val);
   else if (!low_default_is_valid)
     complaint (&symfile_complaints, _("Missing DW_AT_lower_bound "
 				      "- DIE at 0x%x [in module %s]"),
@@ -14217,10 +14221,10 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
              either; we just represent them as zero-length
              arrays.  Choose an appropriate upper bound given
              the lower bound we've computed above.  */
-          high = low - 1;
+          high.data.const_val = low.data.const_val - 1;
         }
       else
-        high = dwarf2_get_attr_constant_value (attr, 1);
+        high.data.const_val = dwarf2_get_attr_constant_value (attr, 1);
     }
   else
     {
@@ -14228,12 +14232,12 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
       if (attr)
 	{
 	  int count = dwarf2_get_attr_constant_value (attr, 1);
-	  high = low + count - 1;
+	  high.data.const_val = low.data.const_val + count - 1;
 	}
       else
 	{
 	  /* Unspecified array length.  */
-	  high = low - 1;
+	  high.data.const_val = low.data.const_val - 1;
 	}
     }
 
@@ -14277,12 +14281,14 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
 
   negative_mask =
     (LONGEST) -1 << (TYPE_LENGTH (base_type) * TARGET_CHAR_BIT - 1);
-  if (!TYPE_UNSIGNED (base_type) && (low & negative_mask))
-    low |= negative_mask;
-  if (!TYPE_UNSIGNED (base_type) && (high & negative_mask))
-    high |= negative_mask;
-
-  range_type = create_range_type (NULL, orig_base_type, low, high);
+  if (low.kind == DWARF_CONST
+      && !TYPE_UNSIGNED (base_type) && (low.data.const_val & negative_mask))
+    low.data.const_val |= negative_mask;
+  if (high.kind == DWARF_CONST
+      && !TYPE_UNSIGNED (base_type) && (high.data.const_val & negative_mask))
+    high.data.const_val |= negative_mask;
+
+  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
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 9069a11..3cfcf62 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -796,6 +796,27 @@ allocate_stub_method (struct type *type)
   return mtype;
 }
 
+struct type *
+create_range_type_1 (struct type *result_type, struct type *index_type,
+		     const struct dwarf2_prop *low_bound,
+		     const struct dwarf2_prop *high_bound)
+{
+  if (result_type == NULL)
+    result_type = alloc_type_copy (index_type);
+  TYPE_CODE (result_type) = TYPE_CODE_RANGE;
+  TYPE_TARGET_TYPE (result_type) = index_type;
+  if (TYPE_STUB (index_type))
+    TYPE_TARGET_STUB (result_type) = 1;
+  else
+    TYPE_LENGTH (result_type) = TYPE_LENGTH (check_typedef (index_type));
+  TYPE_RANGE_DATA (result_type) = (struct range_bounds *)
+    TYPE_ZALLOC (result_type, sizeof (struct range_bounds));
+  TYPE_RANGE_DATA (result_type)->low = *low_bound;
+  TYPE_RANGE_DATA (result_type)->high = *high_bound;
+
+  return result_type;
+}
+
 /* Create a range type using either a blank type supplied in
    RESULT_TYPE, or creating a new type, inheriting the objfile from
    INDEX_TYPE.
@@ -810,18 +831,16 @@ struct type *
 create_range_type (struct type *result_type, struct type *index_type,
 		   LONGEST low_bound, LONGEST high_bound)
 {
-  if (result_type == NULL)
-    result_type = alloc_type_copy (index_type);
-  TYPE_CODE (result_type) = TYPE_CODE_RANGE;
-  TYPE_TARGET_TYPE (result_type) = index_type;
-  if (TYPE_STUB (index_type))
-    TYPE_TARGET_STUB (result_type) = 1;
-  else
-    TYPE_LENGTH (result_type) = TYPE_LENGTH (check_typedef (index_type));
-  TYPE_RANGE_DATA (result_type) = (struct range_bounds *)
-    TYPE_ZALLOC (result_type, sizeof (struct range_bounds));
-  TYPE_LOW_BOUND (result_type) = low_bound;
-  TYPE_HIGH_BOUND (result_type) = high_bound;
+  struct dwarf2_prop low, high;
+
+  low.kind = DWARF_CONST;
+  low.data.const_val = low_bound;
+
+  high.kind = DWARF_CONST;
+  high.data.const_val = high_bound;
+
+  result_type = create_range_type_1 (result_type, index_type,
+				     &low, &high);
 
   if (low_bound >= 0)
     TYPE_UNSIGNED (result_type) = 1;
diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
index d7fdedf..f563a1c 100644
--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -365,6 +365,29 @@ enum type_instance_flag_value
 #define TYPE_ADDRESS_CLASS_ALL(t) (TYPE_INSTANCE_FLAGS(t) \
 				   & TYPE_INSTANCE_FLAG_ADDRESS_CLASS_ALL)
 
+/* Used to store bound information for a type.  */
+
+struct dwarf2_prop
+{
+  /* Determine which field of the union dwarf2_prop.data is used.  */
+  enum
+  {
+    DWARF_CONST,
+    DWARF_LOCEXPR,
+    DWARF_LOCLIST
+  } kind;
+
+  /* Stores information as location expression, location list,
+     or constant value.  */
+  union data
+  {
+    LONGEST const_val;
+    struct dwarf2_locexpr_baton *locexpr;
+    struct dwarf2_loclist_baton *loclist;
+  } data;
+};
+
+
 /* Determine which field of the union main_type.fields[x].loc is used.  */
 
 enum field_loc_kind
@@ -589,11 +612,11 @@ struct main_type
     {
       /* Low bound of range.  */
 
-      LONGEST low;
+      struct dwarf2_prop low;
 
       /* High bound of range.  */
 
-      LONGEST high;
+      struct dwarf2_prop high;
 
       /* Flags indicating whether the values of low and high are
          valid.  When true, the respective range value is
@@ -1066,8 +1089,10 @@ extern void allocate_gnat_aux_type (struct type *);
 
 #define TYPE_INDEX_TYPE(type) TYPE_FIELD_TYPE (type, 0)
 #define TYPE_RANGE_DATA(thistype) TYPE_MAIN_TYPE(thistype)->flds_bnds.bounds
-#define TYPE_LOW_BOUND(range_type) TYPE_RANGE_DATA(range_type)->low
-#define TYPE_HIGH_BOUND(range_type) TYPE_RANGE_DATA(range_type)->high
+#define TYPE_LOW_BOUND(range_type) \
+  TYPE_RANGE_DATA(range_type)->low.data.const_val
+#define TYPE_HIGH_BOUND(range_type) \
+  TYPE_RANGE_DATA(range_type)->high.data.const_val
 #define TYPE_LOW_BOUND_UNDEFINED(range_type) \
    TYPE_RANGE_DATA(range_type)->low_undefined
 #define TYPE_HIGH_BOUND_UNDEFINED(range_type) \
@@ -1526,6 +1551,11 @@ extern struct type *lookup_function_type_with_arguments (struct type *,
 							 int,
 							 struct type **);
 
+extern struct type *create_range_type_1 (struct type *, struct type *,
+					 const struct dwarf2_prop *,
+					 const struct dwarf2_prop *);
+
+
 extern struct type *create_range_type (struct type *, struct type *, LONGEST,
 				       LONGEST);
 
-- 
1.7.0.7