vla: introduce new bound type abstraction adapt uses

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 BOUND_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 bound_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 bound_prop and pass
	them to create_range_type_1.
	* gdbtypes.h (struct bound_prop): New struct.
	(create_range_type_1): New function prototype.
	(struct range_bounds): Use struct bound_prop instead of LONGEST for
	high/low bounds. Remove low_undefined/high_undefined and adapt all uses.
	(TYPE_LOW_BOUND,TYPE_HIGH_BOUND): Adapt macros to refer to the static
	part of the bound.
	* parse.c (follow_types): Set high bound kind to BOUND_UNDEFINED.

Change-Id: I06fbeb877255a541a770c897e4b53d65f21dbbef
type: add c99 variable length array support

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.
	* value.c (value_from_contents_and_address): Call resolve_dynamic_type
	to resolve dynamic properties of the type. Update comment.
	* valops.c (get_value_at, value_at, value_at_lazy): Update comment.

Change-Id: I59036232c0b93e79427bf34041b3bbf8992e731a
vla: enable sizeof operator to work with variable length arrays

In C99 the sizeof operator computes the size of a variable length array
at runtime (6.5.3.4 The sizeof operator). This patch reflects the semantic
change in the debugger.

We now are able to get the size of a vla:

1| void foo (size_t n) {
2|   int vla[n];
3| }

(gdb) p sizeof(vla)

yields N * sizeof(int).

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

	* eval.c (evaluate_subexp_for_sizeof): If the type passed to sizeof is
	dynamic  evaluate the argument to compute the length.

Change-Id: I79656d4ec5bd5d728748a1059ac414a5440eb659
vla: enable sizeof operator for indirection

This patch enables the sizeof operator for indirections:

1| void foo (size_t n) {
2|   int vla[n];
3|   int *vla_ptr = &vla;
4| }

(gdb) p sizeof(*vla_ptr)

yields sizeof (size_t) * n.

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

	* eval.c (evaluate_subexp_for_sizeof): Create a indirect value and
	retrieve the dynamic type size.

Change-Id: I3dbe85ebbc87ca93115a1952316b6436f750a16d
vla: update type from newly created value

Constructing a value based on a type and address might change the type
of the newly constructed value. Thus re-fetch type via value_type to ensure
we have the correct type at hand.

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

	* ada-lang.c (ada_value_primitive_packed_val): Re-fetch type from value.
	(ada_template_to_fixed_record_type_1): Likewise.
	(ada_to_fixed_type_1): Likewise.
	* cp-valprint.c (cp_print_value_fields_rtti): Likewise.
	(cp_print_value): Likewise.
	* d-valprint.c (dynamic_array_type): Likewise.
	* jv-valprint.c (java_value_print): Likewise.
	* valops.c (value_ind): Likewise.
	* value.c (coerce_ref): Likewise.

Change-Id: I8a0ebcbd84d8ff8db2eb24960f099d131816cb18
vla: print "variable length" for unresolved dynamic bounds

1| void foo (size_t n) {
2|   int vla[n];
3| }

Given the following expression

  (gdb) ptype &vla

Gdb evaluates the expression with EVAL_AVOID_SIDE_EFFECTS and thus
does not resolve the bounds information and misinterprets the high
bound as a constant. The current output is:

  type = int (*)[1289346]

this patch deals with this case and prints:

  type = int (*)[variable length]

instead.

2013-08-30  Keven Boell  <keven.boell@intel.com>
            Sanimir Agovic  <sanimir.agovic@intel.com>

	* c-typeprint.c (c_type_print_varspec_suffix): Added
	check for not yet resolved high bound. If unresolved, print
	"variable length" string to the console instead of random
	length.

Change-Id: Ic6a5fc08c8651ef18760bdacacc492ed44fe4af4
vla: support for DW_AT_count

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): If DW_AT_count is dynamic
	create the following upper bound dwarf expression 'low + count + 1'
	by hand.

Change-Id: I0f70edd22f2f6d8d7aa32f245e45617a7dc1b24a
vla: resolve dynamic bounds if value contents is a constant byte-sequence

A variable location might be a constant value and therefore no inferior memory
access is needed to read the content. In this case try to resolve the type
bounds.

2013-11-26  Sanimir Agovic  <sanimir.agovic@intel.com>
            Keven Boell  <keven.boell@intel.com>

	* findvar.c (default_read_var_value): Resolve dynamic bounds if location
	points to a constant blob.

Change-Id: I73c31b64976b7d2c603c68d4584909502c8c5928
test: cover subranges with present DW_AT_count attribute

The dwarf attribute DW_AT_count specifies the elements of a subrange.
This test covers subranges with present count but absent upper bound
attribute, both with static and dynamic attribute values.

2013-11-26  Sanimir Agovic  <sanimir.agovic@intel.com>
            Keven Boell  <keven.boell@intel.com>

testsuite:
	* gdb.dwarf2/count.exp: New test.

Change-Id: I0a537c23bc7d5e0bffe58d14d0125dc7cd753f48
test: multi-dimensional c99 vla.

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

gdb/testsuite:
	* gdb.base/vla-multi.c: New. Test source file
	for testing multi-dimensional VLA's in C.
	* gdb.base/vla-multi.exp: New. Tests ensure
	that multi-dimensional VLA's can be evaluated
	correctly in C.

Change-Id: If9cf7517301e0558aced1358723e1b62f6df0c97
test: evaluate pointers to C99 vla correctly.

2013-10-18  Keven Boell  <keven.boell@intel.com>

gdb/testsuite:
	* gdb.base/vla-ptr.c: New. Test source file
	for testing pointers to VLA's in C.
	* gdb.base/vla-ptr.exp: New. Tests ensure that
	the evaluation of pointers to VLA's work
	correctly in C.

Change-Id: Iea007544b3e95f9da4ca746d142e7be0350cf87b
test: basic c99 vla tests for C primitives

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

gdb/testsuite:
	* gdb.base/vla-datatypes.c: New. Test source file
	for VLA datatype checks.
	* gdb.base/vla-datatypes.exp: New. Tests ensure that
	a VLA in C can be evaluated correctly with standard
	C types.

Change-Id: I7e9ac796ac7e9afa983d60e6d4b506017e4afe54
test: add mi vla test

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

testsuite/gdb.mi/

	* mi-vla-c99.exp: New file.
	* vla.c: New file.

Change-Id: If86f3a770c9c1d6b415057a40f51ba2a6f20ba0e
dwarf: add dwarf3 DW_OP_push_object_address opcode

The opcode pushes the address of the object being evaluated. The semantic is
equivalent to the implicit push of the base address of a data member location.

2013-11-20  Sanimir Agovic  <sanimir.agovic@intel.com>
            Keven Boell  <keven.boell@intel.com>

	* dwarf2expr.c (execute_stack_op): Add case for
	DW_OP_push_object_address opcode which returns the object address.
	* dwarf2expr.h (struct dwarf_expr_context_funcs): New function pointer
	get_object_addr.
	* dwarf2loc.c (struct dwarf_expr_baton): Add obj_address.
	(dwarf_expr_get_obj_addr): New function.
	(struct dwarf_expr_context_funcs): Add
	dwarf_expr_get_obj_addr to dwarf_expr_ctx_funcs.
	(dwarf2_evaluate_loc_desc_full): Initialize baton.obj_address.
	(dwarf2_locexpr_baton_eval): Set baton.obj_address to addr.
	(needs_get_obj_addr): New function.
	(struct dwarf_expr_context_funcs): Add needs_get_obj_addr to
	needs_frame_ctx_funcs.

Change-Id: Ic376b22c8f94e630ddba21ac71849d79b8c06ebc
dwarf: add DW_AT_data_location support

The attribute DW_AT_data_location is used for indirection to actual data.

2013-11-20  Sanimir Agovic  <sanimir.agovic@intel.com>
            Keven Boell  <keven.boell@intel.com>

	* dwarf2read.c (set_die_type): Parse and save DW_AT_data_location
	attribute.
	* gdbtypes.c (is_dynamic_type): Consider a type being dynamic if
	the data location has not yet been resolved.
	(resolve_dynamic_bounds): Evaluate data location baton
	if present and save its value.
	* gdbtypes.h (struct main_type): Add data_location.
	(TYPE_DATA_LOCATION): New macro.
	(TYPE_DATA_LOCATION_ADDR): New macro.
	(TYPE_DATA_LOCATION_IS_ADDRESS): New macro.
	* value.c: Include dwarf2loc.h.
	(value_fetch_lazy): Use data location addres to read value from
	memory.
	(coerce_ref): Construct new value from data location.

Change-Id: I9f303a6891d1dc50ce4ea64072a99cf0ddc10b62