This PR is about an assertion failure in GDB that can be triggered by
setting "backtrace limit" to a value that causes GDB to stop unwinding
after an inline frame. In this case, an assertion in
inline_frame_this_id will trigger:
/* We need a valid frame ID, so we need to be based on a valid
frame. (...). */
gdb_assert (frame_id_p (*this_id));
Looking at the function:
static void
inline_frame_this_id (struct frame_info *this_frame,
void **this_cache,
struct frame_id *this_id)
{
struct symbol *func;
/* In order to have a stable frame ID for a given inline function,
we must get the stack / special addresses from the underlying
real frame's this_id method. So we must call get_prev_frame.
Because we are inlined into some function, there must be previous
frames, so this is safe - as long as we're careful not to
create any cycles. */
*this_id = get_frame_id (get_prev_frame (this_frame));
we see we're computing the frame id for the inline frame. If this is
an inline frame, which is a virtual frame constructed based on debug
info, on top of a real stack frame, we should _always_ be able to find
where the frame was inlined into, as that ultimately just means
peeling off the virtual frames on top of the real stack frame. If
there ultimately was no prev (real) stack frame, then we wouldn't have
been able to construct the inline frame either, by design. That's
what the assertion catches.
So we have an inline frame, we should _always_ be able to compute its
ID, even if that means bypassing the user backtrace limits to get at
the real stack frame's info. The problem is that inline_frame_id
calls get_prev_frame, and that takes user backtrace limits into
account. Code that wants to bypass the limits calls get_prev_frame_1
instead.
Note how get_prev_frame_1 already skips all checks for inline frames:
/* If we are unwinding from an inline frame, all of the below tests
were already performed when we unwound from the next non-inline
frame. We must skip them, since we can not get THIS_FRAME's ID
until we have unwound all the way down to the previous non-inline
frame. */
if (get_frame_type (this_frame) == INLINE_FRAME)
return get_prev_frame_if_no_cycle (this_frame);
And note how the related frame_unwind_caller_id function also uses
get_prev_frame_1:
struct frame_id
frame_unwind_caller_id (struct frame_info *next_frame)
{
struct frame_info *this_frame;
/* Use get_prev_frame_1, and not get_prev_frame. The latter will truncate
the frame chain, leading to this function unintentionally
returning a null_frame_id (e.g., when a caller requests the frame
ID of "main()"s caller. */
next_frame = skip_artificial_frames (next_frame);
this_frame = get_prev_frame_1 (next_frame);
if (this_frame)
return get_frame_id (skip_artificial_frames (this_frame));
else
return null_frame_id;
}
get_prev_frame_1 is currently static in frame.c. As a _1 suffix is
not a good name for an extern function, I've renamed it.
Tested on x86-64 Fedora 17.
gdb/
2014-04-18 Pedro alves <palves@redhat.com>
Tom Tromey <tromey@redhat.com>
PR backtrace/15558
* frame.c (get_prev_frame_1): Rename to ...
(get_prev_frame_always): ... this, and make extern. Adjust.
(skip_artificial_frames): Use get_prev_frame_always.
(frame_unwind_caller_id, frame_pop, get_prev_frame)
(get_frame_unwind_stop_reason): Adjust to rename.
* frame.h (get_prev_frame_always): Declare.
* inline-frame.c: Include frame.h.
(inline_frame_this_id): Use get_prev_frame_always.
gdb/testsuite/
2014-04-18 Tom Tromey <palves@redhat.com>
Pedro alves <tromey@redhat.com>
PR backtrace/15558
* gdb.opt/inline-bt.exp: Test backtracing from an inline function
with a backtrace limit.
* gdb.python/py-frame-inline.exp: Test running to an inline
function with a backtrace limit, and printing the newest frame.
* gdb.python/py-frame-inline.c (main): Call f.
Use bfd_mach_o_get_base_address to extract load address.
gdb/
* solib-darwin.c (darwin_solib_create_inferior_hook): Simplify
code by using bfd_mach_o_get_base_address.
This patch enables use of DWARF unwinders for the SPU target.
In addition to appending the DWARF unwinders, we also need to install
a spu_dwarf_reg_to_regnum that maps the raw stack pointer register to
the cooked version (to avoid mismatches with gdbarch_sp_regnum).
This also causes confusion with the AX collect handling, so we also
install ax_pseudo_register routines to handle the cooked SP.
gdb/
2014-04-17 Ulrich Weigand <uweigand@de.ibm.com>
* spu-tdep.c: Include "dwarf2-frame.h" and "ax.h".
(spu_ax_pseudo_register_collect): New function.
(spu_ax_pseudo_register_push_stack): Likewise.
(spu_dwarf_reg_to_regnum): Likewise.
(spu_gdbarch_init): Install them. Append DWARF unwinders.
This patch fixes a problem that prevented use of the Dwarf unwinders on SPU,
because dwarf2-frame.c common code did not support the situation where the
stack and/or frame pointer is maintained in a *vector* register. This is
because read_addr_from_reg is hard-coded to assume that such pointers can
be read from registers via a simple get_frame_register / unpack_pointer
operation.
Now, there *is* a routine address_from_register that calls into the
appropriate tdep routines to handle pointer values in "weird" registers
like on SPU, but it turns out I cannot simply change dwarf2-frame.c to
use address_from_register. This is because address_from_register uses
value_from_register to create a (temporary) value, and that routine
at some point calls get_frame_id in order to set up that value's
VALUE_FRAME_ID entry.
However, the dwarf2-frame.c read_addr_from_reg routine will be called
during early unwinding (to unwind the frame's CFA), at which point the
frame's ID is not actually known yet! This would cause an assert.
On the other hand, we may notice that VALUE_FRAME_ID is only needed in the
value returned by value_from_register if that value is later used as an
lvalue. But this is obviously never done to the temporary value used in
address_from_register. So, if we could change address_from_register to
not call value_from_register but instead accept constructing a value
that doesn't have VALUE_FRAME_ID set, things should be fine.
To do that, we can change the value_from_register callback to accept
a FRAME_ID instead of a FRAME; the only existing uses of the FRAME
argument were either to extract its frame ID, or its gdbarch. (To
keep a way of getting at the latter, we also change the callback's
type from "f" to "m".) Together with the required follow-on changes
in the existing value_from_register implementations (including the
default one), this seems to fix the problem.
As another minor interface cleanup, I've removed the explicit TYPE
argument from address_from_register. This routine really always
uses a default pointer type, and in the new implementation it -to
some extent- relies on that fact, in that it will now no longer
handle types that require gdbarch_convert_register_p handling.
gdb:
2014-04-17 Ulrich Weigand <uweigand@de.ibm.com>
* gdbarch.sh (value_from_register): Make class "m" instead of "f".
Replace FRAME argument with FRAME_ID.
* gdbarch.c, gdbarch.h: Regenerate.
* findvar.c (default_value_from_register): Add GDBARCH argument;
replace FRAME by FRAME_ID. No longer call get_frame_id.
(value_from_register): Update call to gdbarch_value_from_register.
* value.h (default_value_from_register): Update prototype.
* s390-linux-tdep.c (s390_value_from_register): Update interface
and call to default_value_from_register.
* spu-tdep.c (spu_value_from_register): Likewise.
* findvar.c (address_from_register): Remove TYPE argument.
Do not call value_from_register; use gdbarch_value_from_register
with null_frame_id instead.
* value.h (address_from_register): Update prototype.
* dwarf2-frame.c (read_addr_from_reg): Use address_from_register.
* dwarf2loc.c (dwarf_expr_read_addr_from_reg): Update for
address_from_register interface change.
Nowadays, we have one page on "GDB Types" generated by doxygen, but types
and macros referenced in doc are not linked to their definitions. This
patch tweaks the comments a little to use doxygen syntax so that these
types and macros are linked their definitions.
Is it OK?
gdb:
2014-04-17 Yao Qi <yao@codesourcery.com>
* gdbtypes.h: Update comments to link to types and macros'
definitions.
Install some sanity checks that sibling DIE offsets are not beyond the
defined limits of the DWARF input buffer in read_partial_die and skip_one_die.
2014-03-20 Keith Seitz <keiths@redhat.com>
PR gdb/15827
* dwarf2read.c (skip_one_die): Check that all relative-offset
sibling DIEs fall within range of the current reader's buffer.
(read_partial_die): Likewise.
2014-03-20 Keith Seitz <keiths@redhat.com>
PR gdb/15827
* gdb.dwarf2/corrupt.c: New file.
* gdb.dwarf2/corrupt.exp: New file.
[forgot to commit/push these with previous push]
If lookup_symbol_file tries to locate a member variable with NULL name:
/* A simple lookup failed. Check if the symbol was defined in
a base class. */
cleanup = make_cleanup (null_cleanup, NULL);
/* Find the name of the class and the name of the method,
variable, etc. */
prefix_len = cp_entire_prefix_len (name);
/* If no prefix was found, search "this". */
if (prefix_len == 0)
{
struct type *type;
struct symbol *this;
this = lookup_language_this (language_def (language_cplus), block);
if (this == NULL)
{
do_cleanups (cleanup);
return NULL;
}
type = check_typedef (TYPE_TARGET_TYPE (SYMBOL_TYPE (this)));
klass = xstrdup (TYPE_NAME (type));
nested = xstrdup (name);
}
TYPE_NAME (type) is NULL, so xstrdup (NULL) and boom!
This can happen, e.g., with clang++. See testsuite/gdb.cp/namelessclass.exp
or the bugzilla report.
This patch simply adds a fencepost against this case, allowing the caller
of lookup_symbol_file to search other blocks for the right symbol.
PR c++/16253.
symbol_matches_domain was permitting searches for a VAR_DOMAIN
symbol to also match STRUCT_DOMAIN symbols for languages like C++
where STRUCT_DOMAIN symbols also define a typedef of the same name,
e.g., "struct foo {}" introduces a typedef of the name "foo".
Problems occur if there exists both a VAR_DOMAIN and STRUCT_DOMAIN
symbol of the same name. Then it is essentially a race between which
symbol is found first. The other symbol is obscurred.
[This is a relatively common idiom: enum e { ... } e;]
This patchset moves this "language defines a typedef" logic to
lookup_symbol[_in_language], looking first for a symbol in the given
domain and falling back to searching STRUCT_DOMAIN when/if appropriate.
2014-04-14 Keith Seitz <keiths@redhat.com>
PR c++/16253
* ada-lang.c (ada_symbol_matches_domain): Moved here and renamed
from symbol_matches_domain in symtab.c. All local callers
of symbol_matches_domain updated.
(standard_lookup): If DOMAIN is VAR_DOMAIN and no symbol is found,
search STRUCT_DOMAIN.
(ada_find_any_type_symbol): Do not search STRUCT_DOMAIN
independently. standard_lookup will do that automatically.
* cp-namespace.c (cp_lookup_symbol_nonlocal): Explain when/why
VAR_DOMAIN searches may return a STRUCT_DOMAIN match.
(cp_lookup_symbol_in_namespace): Likewise.
If no VAR_DOMAIN symbol is found, search STRUCT_DOMAIN.
(cp_lookup_symbol_exports): Explain when/why VAR_DOMAIN searches
may return a STRUCT_DOMAIN match.
(lookup_symbol_file): Search for the class name in STRUCT_DOMAIN.
* cp-support.c: Include language.h.
(inspect_type): Explicitly search STRUCT_DOMAIN before searching
VAR_DOMAIN.
* psymtab.c (match_partial_symbol): Compare the requested
domain with the symbol's domain directly.
(lookup_partial_symbol): Likewise.
* symtab.c (lookup_symbol_in_language): Explain when/why
VAR_DOMAIN searches may return a STRUCT_DOMAIN match.
If no VAR_DOMAIN symbol is found, search STRUCT_DOMAIN for
appropriate languages.
(symbol_matches_domain): Renamed `ada_symbol_matches_domain'
and moved to ada-lang.c
(lookup_block_symbol): Explain that this function only returns
symbol matching the requested DOMAIN.
Compare the requested domain with the symbol's domain directly.
(iterate_over_symbols): Compare the requested domain with the
symbol's domain directly.
* symtab.h (symbol_matches_domain): Remove.
2014-04-14 Keith Seitz <keiths@redhat.com>
PR c++/16253
* gdb.cp/var-tag.cc: New file.
* gdb.cp/var-tag.exp: New file.
* gdb.dwarf2/dw2-ada-ffffffff.exp: Set the language to C++.
* gdb.dwarf2/dw2-anon-mptr.exp: Likewise.
* gdb.dwarf2/dw2-double-set-die-type.exp: Likewise.
* gdb.dwarf2/dw2-inheritance.exp: Likewise.
This adds support for the C++11 "enum class" feature. This is
PR c++/15246.
I chose to use the existing TYPE_DECLARED_CLASS rather than introduce
a new type code. This seemed both simple and clear to me.
I made overloading support for the new enum types strict. This is how
it works in C++; and it didn't seem like an undue burden to keep this,
particularly because enum constants are printed symbolically by gdb.
Built and regtested on x86-64 Fedora 20.
2014-04-14 Tom Tromey <tromey@redhat.com>
PR c++/15246:
* c-exp.y (type_aggregate_p): New function.
(qualified_name, classify_inner_name): Use it.
* c-typeprint.c (c_type_print_base): Handle TYPE_DECLARED_CLASS
and TYPE_TARGET_TYPE of an enum type.
* dwarf2read.c (read_enumeration_type): Set TYPE_DECLARED_CLASS on
an enum type.
(determine_prefix) <case DW_TAG_enumeration_type>: New case;
handle TYPE_DECLARED_CLASS.
* gdbtypes.c (rank_one_type): Handle TYPE_DECLARED_CLASS on enum
types.
* gdbtypes.h (TYPE_DECLARED_CLASS): Update comment.
* valops.c (enum_constant_from_type): New function.
(value_aggregate_elt): Use it.
* cp-namespace.c (cp_lookup_nested_symbol): Handle
TYPE_CODE_ENUM.
2014-04-14 Tom Tromey <tromey@redhat.com>
* gdb.cp/classes.exp (test_enums): Handle underlying type.
* gdb.dwarf2/enum-type.exp: Add test for enum with underlying
type.
* gdb.cp/enum-class.exp: New file.
* gdb.cp/enum-class.cc: New file.
While working on another patch I realized that value_aggregate_elt's
"name" parameter ought to be const. This patch implements this.
2014-04-14 Tom Tromey <tromey@redhat.com>
* valops.c (value_aggregate_elt, value_struct_elt_for_reference)
(value_namespace_elt, value_maybe_namespace_elt): Make "name"
const.
* value.h (value_aggregate_elt): Update.
DWARF allows an enumeration type to have a DW_AT_type. GDB doesn't
recognize this, but there is a patch to change GCC to emit it, and a
DWARF proposal to further allow an enum type with a DW_AT_type to omit
the DW_AT_byte_size. This patch changes gdb to implement this.
Built and regtested on x86-64 Fedora 20.
2014-04-14 Tom Tromey <tromey@redhat.com>
* dwarf2read.c (read_enumeration_type): Handle DW_AT_type.
2014-04-14 Tom Tromey <tromey@redhat.com>
* gdb.dwarf2/enum-type.exp: New file.
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/whatis still do not allow any sideeffects.
This patch was motivated by:
https://sourceware.org/ml/gdb-patches/2014-01/msg00732.html
gdb/ChangeLog:
* 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/ChangeLog:
* gdb.base/vla-sideeffect.c: New file.
* gdb.base/vla-sideeffect.exp: New file.
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.
gdb/ChangeLog:
* findvar.c (default_read_var_value): Resolve dynamic bounds if location
points to a constant blob.
This patch adds support for DW_AT_count as requested in the code review:
https://sourceware.org/ml/gdb-patches/2013-11/msg00200.html
gdb/ChangeLog:
* 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.
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.
gdb/ChangeLog:
* 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.
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.
gdb/ChangeLog
* 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.
* findvar.c (address_of_variable): Likewise.
* jv-valprint.c (java_value_print): Likewise.
* valops.c (value_ind): Likewise.
* value.c (coerce_ref): Likewise.
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.
gdb/ChangeLog:
* eval.c (evaluate_subexp_for_sizeof) <UNOP_IND>: Create an indirect
value and retrieve the dynamic type size.
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).
gdb/ChangeLog:
* eval.c (evaluate_subexp_for_sizeof) <OP_VAR_VALUE>: If the type
passed to sizeof is dynamic evaluate the argument to compute the length.
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>}
gdb/ChangeLog:
* 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.
* guile/scm-value.c (gdbscm_value_dynamic_type): Use coerce_ref to
dereference TYPE_CODE_REF values.
testsuite/
* gdb.guile/scm-value.c: Improve test case.
* gdb.guile/scm-value.exp: Add new test.
This reverts the following patch series, as they cause some regresssions.
commit 37c1ab67a3
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 26cb189f8b
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 04b19544ef
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 bcd629a44f
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 b86138fb04
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 e1969afbd4
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 92b09522dc
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 3bce82377f
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 504f34326e
test: cover subranges with present DW_AT_count attribute
gdb/testsuite/
* gdb.dwarf2/count.exp: New file.
commit 1a237e0ee5
test: multi-dimensional c99 vla.
gdb/testsuite/
* gdb.base/vla-multi.c: New file.
* gdb.base/vla-multi.exp: New file.
commit 024e13b46f
test: evaluate pointers to C99 vla correctly.
gdb/testsuite/
* gdb.base/vla-ptr.c: New file.
* gdb.base/vla-ptr.exp: New file.
commit c8655f75e2
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 58a84dcf29
test: add mi vla test
gdb/testsuite/
* gdb.mi/mi-vla-c99.exp: New file.
* gdb.mi/vla.c: New file.
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.
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.
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.
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.
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.
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.
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.
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.
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.
* 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.
Breakpoints are supposed to be transparent to memory accesses. For
all kinds of breakpoints breakpoint_xfer_memory hides the breakpoint
instructions. However, sss breakpoints aren't tracked like all other
breakpoints, and nothing is taking care of hiding them from memory
reads.
Say, as is, a background step + disassemble will see breakpoints
instructions on software step targets. E.g., stepping over this line:
while (1);
with s&
and then "disassemble" would show sss breakpoints.
Actually, that's still not be possible to see today, because:
- in native Linux, you can't read memory while the program
is running.
- with Linux gdbserver, you can, but in the all-stop RSP you
can't talk to the server while the program is running...
- and with non-stop, on software step targets, we presently
force the use of displaced-stepping for all single-steps,
so no single-step breakpoints are used...
I've been working towards making non-stop not force displaced stepping
on sss targets, and I noticed the issue then. With that, I indeed see
this:
(gdb) set remote Z-packet off
(gdb) s&
(gdb) disassemble main
Dump of assembler code for function main:
0x000000000040049c <+0>: push %rbp
0x000000000040049d <+1>: mov %rsp,%rbp
0x00000000004004a0 <+4>: int3
0x00000000004004a1 <+5>: (bad)
End of assembler dump.
Instead of the correct:
(gdb) disassemble main
Dump of assembler code for function main:
0x000000000040049c <+0>: push %rbp
0x000000000040049d <+1>: mov %rsp,%rbp
0x00000000004004a0 <+4>: jmp 0x4004a0 <main+4>
This is actually one thing that my v1 of the recent "fix a bunch of
run control bugs" series was fixing, because it made sss breakpoints
be regular breakpoints in the breakpoint chain. But dropped it in the
version that landed in the tree, due to some problems.
So instead of making sss breakpoints regular breakpoints, go with a
simpler fix (at least for now) -- make breakpoint_xfer_memory take
software single-step breakpoints into account. After the patch, I get
the correct disassemble output.
Tested on x86_64 Fedora 17, and also on top of my "use software
single-step on x86" series.
Also fixes the issue pointed out by Yao at
https://sourceware.org/ml/gdb-patches/2014-04/msg00045.html, where the
prologue analysis/frame sniffing manages to see software step
breakpoint instructions.
gdb/
2014-04-10 Pedro Alves <palves@redhat.com>
* breakpoint.c (single_step_breakpoints)
(single_step_gdbarch): Move up in the file.
(one_breakpoint_xfer_memory): New function, factored out from ...
(breakpoint_xfer_memory): ... here. Also process single-step
breakpoints.
Due to a thinko, a message could be not understood and ignored. The result
was a dead-lock (gdb is waiting for an event that never happen). The port
of the thread was deallocated before new threads are discovered. As a
consequence, the origin of the message was unknown (instead of being
linked to the newly created thread).
gdb/
* darwin-nat.c (darwin_check_new_threads): Fix port leak, add
comments.
(darwin_decode_exception_message): Free port only after use.
* avr-tdep.c (struct gdbarch_tdep): Mention avrxmega in the comment.
(avr_gdbarch_init): Add xmega architectures given by bfd_architecture
when setting the size of call_length.
gdb.Value.dynamic_type is supposed to work for reference and pointer
values. However, the value object in the function 'valpy_get_dynamic_type'
was being dereferenced using 'value_ind' irrespective of the value type
being TYPE_CODE_PTR or TYPE_CODE_REF. This patch fixes that to use
'coerce_ref' for TYPE_CODE_REF values.
ChangeLog:
* python/py-value.c (valpy_get_dynamic_type): Use coerce_ref to
dereference TYPE_CODE_REF values.
testsuite/
* gdb.python/py-value.c: Improve test case.
* gdb.python/py-value.exp: Add new test.
When a VDSO gets large enough that it doesn't entirely fit in one page,
but not so large that the part described by the program header exceeds
one page, then gdb/BFD doesn't read the section headers and symbol
table information. This patch cures that by passing the size of the
vdso to BFD, and fixes a number of other issues in the BFD code.
bfd/
* elfcode.h (bfd_from_remote_memory): Add "size" parameter.
Consolidate code handling possible section headers past end of
segment. Don't use p_align for page size guess, instead use
minpagesize. Take note of ld.so clearing section headers when
p_memsz > p_filesz. Handle file header specifying no section
headers. Handle zero p_align throughout. Default loadbase to
zero. Add comments. Rename contents_size to high_offset, and
make it a bfd_vma. Delete unnecessary bfd_set_error calls.
* bfd-in.h (bfd_elf_bfd_from_remote_memory): Update prototpe.
* elf-bfd.h (struct elf_backend_data <elf_backend_from_remote_memory>):
Likewise.
(_bfd_elf32_bfd_from_remote_memory): Likewise.
(_bfd_elf64_bfd_from_remote_memory): Likewise.
* elf.c (bfd_elf_bfd_from_remote_memory): Adjust.
* bfd-in2.h: Regnerate.
gdb/
* symfile-mem.c (symbol_file_add_from_memory): Add size parameter.
Pass to bfd_elf_bfd_from_remote_memory. Adjust all callers.
(struct symbol_file_add_from_memory_args): Add size field.
(find_vdso_size): New function.
(add_vsyscall_page): Attempt to find vdso size.
it is possible that gdb gets mach exceptions from an unknown inferior. This
happens when an inferior creates a child and that child gets a signal.
So instead of reporting messages with unknown origins, simply reply to these
notifications. The kernel will then post the unix signal.
gdb/
* darwin-nat.c (darwin_encode_reply): Add prototype.
(darwin_decode_exception_message): Reply to unknown inferiors.
(darwin_decode_message): Handle message by id. Ignore message
to unknown inferior.
(darwin_wait): Discard unknown messages, add debug trace.
* NEWS: Mention it.
* solib.c (solib_read_symbols): Only print symbol loading messages
if requested.
(solib_add): If symbol loading is in "brief" mode, notify user
symbols are being loaded.
(reload_shared_libraries_1): Ditto.
* symfile.c (print_symbol_loading_off): New static global.
(print_symbol_loading_brief): New static global.
(print_symbol_loading_full): New static global.
(print_symbol_loading_enums): New static global.
(print_symbol_loading): New static global.
(print_symbol_loading_p): New function.
(symbol_file_add_with_addrs): Only print symbol loading messages
if requested.
(_initialize_symfile): Register "print symbol-loading" set/show
command.
* symfile.h (print_symbol_loading_p): Declare.
doc/
* gdb.texinfo (Symbols): Document set/show print symbol-loading.
testsuite/
* gdb.base/print-symbol-loading-lib.c: New file.
* gdb.base/print-symbol-loading-main.c: New file.
* gdb.base/print-symbol-loading.exp: New file.
Given the following variable...
BT : Bounded := New_Bounded (Low => 1, High => 3);
... where type Bounded is defined as a simple unconstrained array:
type Bounded is array (Integer range <>) of Integer;
Creating a varobj for that variable, and immediately asking for
varobj updates, GDB says that our varobj changed types!
(gdb)
-var-create bt * bt
^done,name="bt",numchild="3",value="[3]",type="<ref> array (1 .. 3) of integer",has_more="0"
(gdb)
-var-update 1 *
^done,changelist=[{name="bt",value="[3]",in_scope="true",type_changed="true",new_type="<ref> array (1 .. 3) of integer",new_num_children="3",has_more="0"}]
The expected output for the -var-update command is, in this case:
(gdb)
-var-update 1 *
^done,changelist=[]
The problem occurs because the ada-varobj module does not handle
references, and while the references gets stripped when the varobj
gets created, it doesn't when computing varobj updates.
More specifically, when creating the varobj, varobj_create creates
a new value which is a reference to a TYPE_CODE_ARRAY. It then calls
install_new_value which calls coerce_ref with the following comment:
/* We are not interested in the address of references, and given
that in C++ a reference is not rebindable, it cannot
meaningfully change. So, get hold of the real value. */
if (value)
value = coerce_ref (value);
This leaves the varobj's type component still a ref, while
the varobj's value is now our array, without the ref. This explains
why the "value" field in the varobj indicates an array with 3 elements
"[3]" while the "type" field shows a ref to an array. Generally
speaking, most users have said that showing the ref was a useful
piece of information, so this patch is not touching this part.
Next, when the user issues the -var-update request, varobj_update
calls value_of_root to compute the varobj's new value as well as
determine whether the value's type has changed or not. What happens
in a nutshell is that it calls value_of_root_1 (which re-evaluates
the expression and returns the corresponding new value), finds that
the new value is not NULL, and thus asks whether it has mutated:
else if (varobj_value_has_mutated (var, value, value_type (value)))
This then indirectly delegates the determination to the language-specific
callback, which fails, because it does not handle references.
This patch fixes the issue by adjusting varobj_value_has_mutated to
expect references, and strip them when seen. This allows the various
language-specific implementations to remain unaware of references.
gdb/ChangeLog:
* varobj.c (varobj_value_has_mutated): If NEW_VALUE is
a reference, strip the reference layer before calling
the lang_ops value_has_mutated callback.
gdb/testsuite/ChangeLog:
* gdb.ada/mi_dyn_arr: New testcase.
