Check file exists before completion tests

Doug told me that there are some regressions in gdb.base/completion.exp.
They are caused by my recent change, and can be reproduced via:

$ make check-parallel TESTS=gdb.base/completion.exp
FAIL: gdb.base/completion.exp: complete target core ./gdb.base/completion
FAIL: gdb.base/completion.exp: complete target tfile ./gdb.base/completion
FAIL: gdb.base/completion.exp: complete target exec ./gdb.base/completion

Current tests assume that gdb.base/completion exists but that is wrong
in a parallel run, because binary file and object files are placed
in outputs/gdb.base/completion/.

This patch is to check file exists on two candidate directories,
"gdb.base" and "outputs/gdb.base/completion/", and run tests with files
existed in either of them.

gdb/testsuite:

2014-04-11  Yao Qi  <yao@codesourcery.com>

	* gdb.base/completion.exp: Check file exists before running tests
	on file completion.
Regenerate header files after this commit:

  2014-04-10  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>

	* reloc.c: Add BFD_RELOC_AVR_DIFF8/16/32 relocations
refactoring: rename create_range_type to create_static_range_type

	* gdbtypes.c (create_static_range_type): Renamed from create_range_type.
	* gdbtypes.h (create_static_range_type): Renamed from create_range_type.
	* ada-lang.c: All uses of create_range_type updated.
	* coffread.c: All uses of create_range_type updated.
	* dwarf2read.c: All uses of create_range_type updated.
	* f-exp.y: All uses of create_range_type updated.
	* m2-valprint.c: All uses of create_range_type updated.
	* mdebugread.c: All uses of create_range_type updated.
	* stabsread.c: All uses of create_range_type updated.
	* valops.c: All uses of create_range_type updated.
	* valprint.c: All uses of create_range_type updated.
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 introduced.

	* dwarf2read.c (read_subrange_type): Use struct bound_prop for
	declaring high/low bounds and change uses accordingly. Call
	create_range_type instead of create_static_range_type.
	* gdbtypes.c (create_range_type): New function.
	(create_range_type): Convert bounds into struct bound_prop and pass
	them to create_range_type.
	* gdbtypes.h (struct bound_prop): New struct.
	(create_range_type): 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.
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>}

	* dwarf2loc.c (dwarf2_locexpr_baton_eval): New function.
	(dwarf2_evaluate_property): New function.
	* dwarf2loc.h (dwarf2_evaluate_property): New function prototype.
	* dwarf2read.c (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.
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).

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

	* eval.c (evaluate_subexp_for_sizeof) <UNOP_IND>: Create an indirect
	value and retrieve the dynamic type size.
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.

	* 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.
	* eval.c (evaluate_subexp_with_coercion): Likewise.
	* findvar.c (address_of_variable): Likewise.
	* jv-valprint.c (java_value_print): Likewise.
	* valops.c (value_ind): Likewise.
	* value.c (coerce_ref): Likewise.
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.

	* 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.
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

	* 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.
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.

	* findvar.c (default_read_var_value): Resolve dynamic bounds if location
	points to a constant blob.
vla: evaluate operand of sizeof if its type is a vla

The c99 standard in "6.5.3.4 The sizeof operator" states:

 If the type of the operand is a variable length array type, the operand
 is evaluated;[...]

This patch mirrors the following c99 semantic in gdb:

 1| int vla[n][m];
 2| int i = 1;
 3| sizeof(vla[i++][0]); // No sideffect
 4| assert (i == 1);
 5| sizeof(vla[i++]);    // With sideffect
 6| assert (i == 2);

Note: ptype/whatsis still do not allow any sideeffects.

This patch was motivated by:

  https://sourceware.org/ml/gdb-patches/2014-01/msg00732.html

	* eval.c (evaluate_subexp_for_sizeof): Add enum noside argument.
	(evaluate_subexp_standard): Pass noside argument.
	(evaluate_subexp_for_sizeof) <BINOP_SUBSCRIPT>: Handle subscript case
	if noside equals EVAL_NORMAL. If the subscript yields a vla type
	re-evaluate subscript operation with EVAL_NORMAL to enable sideffects.
	* gdbtypes.c (resolve_dynamic_bounds): Mark bound as evaluated.
	* gdbtypes.h (enum range_flags): Add RANGE_EVALUATED case.

testsuite/gdb.base/

	* vla-sideeffect.c: New file.
	* vla-sideeffect.exp: New file.
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.

testsuite:
	* gdb.dwarf2/count.exp: New file.
test: multi-dimensional c99 vla.

gdb/testsuite:
	* gdb.base/vla-multi.c: New file.
	* gdb.base/vla-multi.exp: New file.
test: evaluate pointers to C99 vla correctly.

gdb/testsuite:
	* gdb.base/vla-ptr.c: New file.
	* gdb.base/vla-ptr.exp: New file.
test: basic c99 vla tests for C primitives

gdb/testsuite:
	* gdb.base/vla-datatypes.c: New file.
	* gdb.base/vla-datatypes.exp: New file.
test: add mi vla test

testsuite/gdb.mi/

	* mi-vla-c99.exp: New file.
	* vla.c: New file.
PE32+ binaries that use addresses > 1^32 have a problem in that the linker
converts some address expressions into absolute values, but the PE format
only stores absolutes as 32-bits.  This is a partial solution which attempts
to convert such absolute values back to section relative ones instead.  It
fails for symbols like __image_base and ImageBase__, but it is unclear as to
whether these values are ever actually used by applications.

	PR ld/16821
	* peXXigen.c (abs_finder): New function.
	(_bfd_XXi_swap_sym_out): For absolute symbols with values larger
	than 1^32 try to convert them into section relative values
	instead.
Fix c++/16675 -- sizeof reference type should give the size of
the referent, not the size of the actual reference variable.
Revert the entire VLA series.

This reverts the following patch series, as they cause some regresssions.

commit 37c1ab67a35025d37d42c449deab5f254f9f59da
type: add c99 variable length array support

	gdb/
	* dwarf2loc.c (dwarf2_locexpr_baton_eval): New function.
	(dwarf2_evaluate_property): New function.
	* dwarf2loc.h (dwarf2_evaluate_property): New function prototype.
	* dwarf2read.c (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.

commit 26cb189f8b46dbe7b2d485525329a8919005ca8a
vla: enable sizeof operator to work with variable length arrays

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

commit 04b19544ef6a97b62b2cc4a3170b900e046ab185
vla: enable sizeof operator for indirection

	gdb/
	* eval.c (evaluate_subexp_for_sizeof) <UNOP_IND>: Create an indirect
	value and retrieve the dynamic type size.

commit bcd629a44fff61527430f353cf77e20fe3afc395
vla: update type from newly created value

	gdb/
	* 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.
	* eval.c (evaluate_subexp_with_coercion): Likewise.
	* findvar.c (address_of_variable): Likewise.
	* jv-valprint.c (java_value_print): Likewise.
	* valops.c (value_ind): Likewise.
	* value.c (coerce_ref): Likewise.

commit b86138fb0484f42db6cb83abed1e3d0ad2ec4eac
vla: print "variable length" for unresolved dynamic bounds

	gdb/
	* 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.

commit e1969afbd454c09c3aad1990305715f70bc47c3c
vla: support for DW_AT_count

	gdb/
	* 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.

commit 92b09522dc5a93ba4bda3c1c0b3c58264e357c8a
vla: resolve dynamic bounds if value contents is a constant byte-sequence

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

commit 3bce82377f683870cc89925ff43aefb7dcce4a77
vla: evaluate operand of sizeof if its type is a vla

	gdb/
	* eval.c (evaluate_subexp_for_sizeof): Add enum noside argument.
	(evaluate_subexp_standard): Pass noside argument.
	(evaluate_subexp_for_sizeof) <BINOP_SUBSCRIPT>: Handle subscript case
	if noside equals EVAL_NORMAL. If the subscript yields a vla type
	re-evaluate subscript operation with EVAL_NORMAL to enable sideffects.
	* gdbtypes.c (resolve_dynamic_bounds): Mark bound as evaluated.
	* gdbtypes.h (enum range_flags): Add RANGE_EVALUATED case.

	gdb/testsuite

	* gdb.base/vla-sideeffect.c: New file.
	* gdb.base/vla-sideeffect.exp: New file.

commit 504f34326e5ae7c78ebfcdd6ed03c7403b42048b
test: cover subranges with present DW_AT_count attribute

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

commit 1a237e0ee53bbdee97d72d794b5b42e774cc81c0
test: multi-dimensional c99 vla.

	gdb/testsuite/
	* gdb.base/vla-multi.c: New file.
	* gdb.base/vla-multi.exp: New file.

commit 024e13b46f9c33d151ae82fd9d64c53092fd9313
test: evaluate pointers to C99 vla correctly.

	gdb/testsuite/
	* gdb.base/vla-ptr.c: New file.
	* gdb.base/vla-ptr.exp: New file.

commit c8655f75e2f0fada311be193e3090087a77ec802
test: basic c99 vla tests for C primitives

	gdb/testsuite/
	* gdb.base/vla-datatypes.c: New file.
	* gdb.base/vla-datatypes.exp: New file.

commit 58a84dcf29b735ee776536b4c51ba90b51612b71
test: add mi vla test

	gdb/testsuite/
	* gdb.mi/mi-vla-c99.exp: New file.
	* gdb.mi/vla.c: New file.