To make it clear that some functions should not modify the variable
object, this patch adds the const qualifier where it makes sense to some
struct varobj * parameters. Most getters should take a const pointer to
guarantee they don't modify the object.
Unfortunately, I couldn't add it to some callbacks (such as name_of_child).
In the C implementation, they call c_describe_child, which calls
varobj_get_path_expr. varobj_get_path_expr needs to modify the object in
order to cache the computed value. It therefore can't take a const
pointer, and it affects the whole call chain. I suppose that's where you
would use a "mutable" in C++.
I did that to make sure there was no other cases like the one fixed in
the previous patch. I don't think it can hurt.
gdb/ChangeLog:
* ada-varobj.c (ada_number_of_children): Constify struct varobj *
parameter.
(ada_name_of_variable): Same.
(ada_path_expr_of_child): Same.
(ada_value_of_variable): Same.
(ada_value_is_changeable_p): Same.
(ada_value_has_mutated): Same.
* c-varobj.c (varobj_is_anonymous_child): Same.
(c_is_path_expr_parent): Same.
(c_number_of_children): Same.
(c_name_of_variable): Same.
(c_path_expr_of_child): Same.
(get_type): Same.
(c_value_of_variable): Same.
(cplus_number_of_children): Same.
(cplus_name_of_variable): Same.
(cplus_path_expr_of_child): Same.
(cplus_value_of_variable): Same.
* jv-varobj.c (java_number_of_children): Same.
(java_name_of_variable): Same.
(java_path_expr_of_child): Same.
(java_value_of_variable): Same.
* varobj.c (number_of_children): Same.
(name_of_variable): Same.
(is_root_p): Same.
(varobj_ensure_python_env): Same.
(varobj_get_objname): Same.
(varobj_get_expression): Same.
(varobj_get_display_format): Same.
(varobj_get_display_hint): Same.
(varobj_has_more): Same.
(varobj_get_thread_id): Same.
(varobj_get_frozen): Same.
(dynamic_varobj_has_child_method): Same.
(varobj_get_gdb_type): Same.
(is_path_expr_parent): Same.
(varobj_default_is_path_expr_parent): Same.
(varobj_get_language): Same.
(varobj_get_attributes): Same.
(varobj_is_dynamic_p): Same.
(varobj_get_child_range): Same.
(varobj_value_has_mutated): Same.
(varobj_get_value_type): Same.
(number_of_children): Same.
(name_of_variable): Same.
(check_scope): Same.
(varobj_editable_p): Same.
(varobj_value_is_changeable_p): Same.
(varobj_floating_p): Same.
(varobj_default_value_is_changeable_p): Same.
* varobj.h (struct lang_varobj_ops): Consitfy some struct varobj *
parameters.
(varobj_get_objname): Constify struct varobj * parameter.
(varobj_get_expression): Same.
(varobj_get_thread_id): Same.
(varobj_get_frozen): Same.
(varobj_get_child_range): Same.
(varobj_get_display_hint): Same.
(varobj_get_gdb_type): Same.
(varobj_get_language): Same.
(varobj_get_attributes): Same.
(varobj_editable_p): Same.
(varobj_floating_p): Same.
(varobj_has_more): Same.
(varobj_is_dynamic_p): Same.
(varobj_ensure_python_env): Same.
(varobj_default_value_is_changeable_p): Same.
(varobj_value_is_changeable_p): Same.
(varobj_get_value_type): Same.
(varobj_is_anonymous_child): Same.
(varobj_value_get_print_value): Same.
(varobj_default_is_path_expr_parent): Same.
It seems like different languages are doing this differently (e.g.
C and Ada). For C, var->path_expr is set inside c_path_expr_of_child.
The next time the value is requested, is it therefore not recomputed.
Ada does not set this field, but just returns the value. Since the field
is never set, the value is recomputed every time it is requested.
This patch makes it so that path_expr_of_child's only job is to compute
the path expression, not save/cache the value. The field is set by the
varobj common code.
gdb/ChangeLog:
* varobj.c (varobj_get_path_expr): Set var->path_expr.
* c-varobj.c (c_path_expr_of_child): Set local var instead of
child->path_expr.
(cplus_path_expr_of_child): Same.
varobj_get_expression returns an allocated string, which must be freed
by the caller.
gdb/ChangeLog:
* mi-cmd-var.c (print_varobj): Free varobj_get_expression
result.
(mi_cmd_var_info_expression): Same.
* varobj.c (varobj_get_expression): Mention in the comment that
the result must by freed by the caller.
varobj_get_type and type_to_string return an allocated string, which is
not freed at a couple of places.
New in v2:
* Rename char * type to type_name.
* Free in all cases in update_type_if_necessary.
gdb/ChangeLog:
* mi/mi-cmd-var.c (mi_cmd_var_info_type): Free result of
varobj_get_type.
(varobj_update_one): Same.
* varobj.c (update_type_if_necessary): Free curr_type_str and
new_type_str.
(varobj_get_type): Specify in comment that the result needs to be
freed by the caller.
Both dwarf2read.c (checkproducer) and utils.c (producer_is_gcc_ge_4)
implemented a GCC producer parser that tried to extract the major and minor
version of GCC. Merge them into one GCC producer parser used by both. Also
allow digits in the identifier after "GNU " such as used by GCC5 like:
"GNU C11 5.0.0 20150123 (experimental) -mtune=generic -march=x86-64 -gdwarf-5"
gdb/ChangeLog:
* dwarf2read.c (checkproducer): Call producer_is_gcc.
* utils.c (producer_is_gcc_ge_4): Likewise.
(producer_is_gcc): New function.
* utils.h (producer_is_gcc): New declaration.
Consider the following declarations:
type Array_Type is array (Integer range <>) of Integer;
type Record_Type (N : Integer) is record
A : Array_Type (1 .. N);
end record;
R : Record_Type := Get (10);
It defines what Ada programers call a "discriminated record", where
"N" is a component of that record called a "discriminant", and where
"A" is a component defined as an array type whose upper bound is
equal to the value of the discriminant.
So far, we rely on a number of fairly complex GNAT-specific encodings
to handle this situation. This patch is to enhance GDB to be able to
print this record in the case where the compiler has been modified
to replace those encodings by pure DWARF constructs.
In particular, the debugging information generated for the record above
looks like the following. "R" is a record..
.uleb128 0x10 # (DIE (0x13e) DW_TAG_structure_type)
.long .LASF17 # DW_AT_name: "foo__record_type"
... whose is is of course dynamic (not our concern here)...
.uleb128 0xd # DW_AT_byte_size
.byte 0x97 # DW_OP_push_object_address
.byte 0x94 # DW_OP_deref_size
.byte 0x4
.byte 0x99 # DW_OP_call4
.long 0x19b
.byte 0x23 # DW_OP_plus_uconst
.uleb128 0x7
.byte 0x9 # DW_OP_const1s
.byte 0xfc
.byte 0x1a # DW_OP_and
.byte 0x1 # DW_AT_decl_file (foo.adb)
.byte 0x6 # DW_AT_decl_line
... and then has 2 members, fist "n" (our discriminant);
.uleb128 0x11 # (DIE (0x153) DW_TAG_member)
.ascii "n\0" # DW_AT_name
.byte 0x1 # DW_AT_decl_file (foo.adb)
.byte 0x6 # DW_AT_decl_line
.long 0x194 # DW_AT_type
.byte 0 # DW_AT_data_member_location
... and "A"...
.uleb128 0x11 # (DIE (0x181) DW_TAG_member)
.ascii "a\0" # DW_AT_name
.long 0x15d # DW_AT_type
.byte 0x4 # DW_AT_data_member_location
... which is an array ...
.uleb128 0x12 # (DIE (0x15d) DW_TAG_array_type)
.long .LASF18 # DW_AT_name: "foo__record_type__T4b"
.long 0x194 # DW_AT_type
... whose lower bound is implicitly 1, and the upper bound
a reference to DIE 0x153 = "N":
.uleb128 0x13 # (DIE (0x16a) DW_TAG_subrange_type)
.long 0x174 # DW_AT_type
.long 0x153 # DW_AT_upper_bound
This patch enhanced GDB to understand references to other DIEs
where the DIE's address is at an offset of its enclosing type.
The difficulty was that the address used to resolve the array's
type (R's address + 4 bytes) is different from the address used
as the base to compute N's address (an offset to R's address).
We're solving this issue by using a stack of addresses rather
than a single address when trying to resolve a type. Each address
in the stack corresponds to each containing level. For instance,
if resolving the field of a struct, the stack should contain
the address of the field at the top, and then the address of
the struct. That way, if the field makes a reference to an object
of the struct, we can retrieve the address of that struct, and
properly resolve the dynamic property references that struct.
gdb/ChangeLog:
* gdbtypes.h (struct dynamic_prop): New PROP_ADDR_OFFSET enum
kind.
* gdbtypes.c (resolve_dynamic_type_internal): Replace "addr"
parameter by "addr_stack" parameter.
(resolve_dynamic_range): Replace "addr" parameter by
"stack_addr" parameter. Update function documentation.
Update code accordingly.
(resolve_dynamic_array, resolve_dynamic_union)
(resolve_dynamic_struct, resolve_dynamic_type_internal): Likewise.
(resolve_dynamic_type): Update code, following the changes made
to resolve_dynamic_type_internal's interface.
* dwarf2loc.h (struct property_addr_info): New.
(dwarf2_evaluate_property): Replace "address" parameter
by "addr_stack" parameter. Adjust function documentation.
(struct dwarf2_offset_baton): New.
(struct dwarf2_property_baton): Update documentation of
field "referenced_type" to be more general. New field
"offset_info" in union data field.
* dwarf2loc.c (dwarf2_evaluate_property): Replace "address"
parameter by "addr_stack" parameter. Adjust code accordingly.
Add support for PROP_ADDR_OFFSET properties.
* dwarf2read.c (attr_to_dynamic_prop): Add support for
DW_AT_data_member_location attributes as well. Use case
statements instead of if/else condition.
gdb/testsuite/ChangeLog:
* gdb.ada/disc_arr_bound: New testcase.
Tested on x86_64-linux, no regression.
This is preparation work to avoid a regression in the Ada/varobj.
An upcoming patch is going to add support for types in DWARF
which have dynamic properties whose value is a reference to another
DIE.
Consider for instance the following declaration:
type Variant_Type (N : Int := 0) is record
F : String(1 .. N) := (others => 'x');
end record;
type Variant_Type_Access is access all Variant_Type;
VTA : Variant_Type_Access := null;
This declares a variable "VTA" which is an access (=pointer)
to a variant record Variant_Type. This record contains two
components, the first being "N" (the discriminant), and the
second being "F", an array whose lower bound is 1, and whose
upper bound depends on the value of "N" (the discriminant).
Of interest to us, here, is that second component ("F"), and
in particular its bounds. The debugging info, and in particular
the info for the array looks like the following...
.uleb128 0x9 # (DIE (0x91) DW_TAG_array_type)
.long .LASF16 # DW_AT_name: "bar__variant_type__T2b"
.long 0xac # DW_AT_GNAT_descriptive_type
.long 0x2cb # DW_AT_type
.long 0xac # DW_AT_sibling
.uleb128 0xa # (DIE (0xa2) DW_TAG_subrange_type)
.long 0xc4 # DW_AT_type
.long 0x87 # DW_AT_upper_bound
.byte 0 # end of children of DIE 0x91
... where the upper bound of the array's subrange type is a reference
to "n"'s DIE (0x87):
.uleb128 0x8 # (DIE (0x87) DW_TAG_member)
.ascii "n\0" # DW_AT_name
[...]
Once the patch to handle this dynamic property gets applied,
this is what happens when creating a varobj for variable "VTA"
(whose value is null), and then trying to list its children:
(gdb)
-var-create vta * vta
^done,name="vta",numchild="2",value="0x0",
type="bar.variant_type_access",has_more="0"
(gdb)
-var-list-children 1 vta
^done,numchild="2",
children=[child={name="vta.n",[...]},
child={name="vta.f",exp="f",
numchild="43877616", <<<<-----
value="[43877616]", <<<<-----
type="array (1 .. n) of character"}],
has_more="0"
It has an odd number of children.
In this case, we cannot really determine the number of children,
since that number depends on the value of a field in a record
for which we do not have a value. Up to now, the value we've been
displaying is zero - meaning we have an empty array.
What happens in this case, is that, because the VTA is a null pointer,
we're not able to resolve the pointer's target type, and therefore
end up asking ada_varobj_get_array_number_of_children to return
the number of elements in that array; for that, it relies blindly
on get_array_bounds, which assumes the type is no longer dynamic,
and therefore the reads the bound without seeing that it's value
is actually a reference rather than a resolved constant.
This patch prevents the issue by explicitly handling the case of
dynamic arrays, and returning zero child in that case.
gdb/ChangeLog:
* ada-varobj.c (ada_varobj_get_array_number_of_children):
Return zero if PARENT_VALUE is NULL and parent_type's
range type is dynamic.
gdb/testsuite/ChangeLog:
* gdb.ada/mi_var_array: New testcase.
Tested on x86_64-linux.
Consider the following code:
type Record_Type (N : Integer) is record
A : Array_Type (1 .. N);
end record;
[...]
R : Record_Type := Get (10);
Trying to print the bounds of the array R.A yielded:
(gdb) p r.a'last
$4 = cannot find reference address for offset property
A slightly different example, but from the same cause:
(gdb) ptype r
type = <ref> record
n: integer;
a: array (cannot find reference address for offset property
Looking at the debugging info, "A" is described as...
.uleb128 0x11 # (DIE (0x181) DW_TAG_member)
.ascii "a\0" # DW_AT_name
.long 0x15d # DW_AT_type
[...]
... which is an array...
.uleb128 0x12 # (DIE (0x15d) DW_TAG_array_type)
.long .LASF18 # DW_AT_name: "foo__record_type__T4b"
.long 0x194 # DW_AT_type
.long 0x174 # DW_AT_sibling
... whose bounds are described as:
.uleb128 0x13 # (DIE (0x16a) DW_TAG_subrange_type)
.long 0x174 # DW_AT_type
.long 0x153 # DW_AT_upper_bound
.byte 0 # end of children of DIE 0x15d
We can see above that the range has an implict lower value of
1, and an upper value which is a reference 0x153="n". All Good.
But looking at the array's subrange subtype, we see...
.uleb128 0x14 # (DIE (0x174) DW_TAG_subrange_type)
.long 0x153 # DW_AT_upper_bound
.long .LASF19 # DW_AT_name: "foo__record_type__T3b"
.long 0x18d # DW_AT_type
... another subrange type whose bounds are exactly described
the same way. So we have a subrange of a subrange, both with
one bound that's dynamic.
What happens in the case above is that GDB's resolution of "R.A"
yields a array whose index type has static bounds. However, the
subtype of the array's index type was left untouched, so, when
taking the subtype of the array's subrange type, we were left
with the unresolved subrange type, triggering the error above.
gdb/ChangeLog:
* gdbtypes.c (is_dynamic_type_internal) <TYPE_CODE_RANGE>: Return
nonzero if the type's subtype is dynamic.
(resolve_dynamic_range): Also resolve the range's subtype.
Tested on x86_64-linux, no regression.
Compilation of (GDB) 7.9.50.20150127-cvs with (GCC) 5.0.0 20150127
fails with
In file included from symfile.c:32:0:
symfile.c: In function 'unmap_overlay_command':
objfiles.h:628:3: error: 'sec' may be used uninitialized in this
function [-Werror=maybe-uninitialized]
for (osect = objfile->sections; osect < objfile->sections_end; osect++) \
^
symfile.c:3442:23: note: 'sec' was declared here
struct obj_section *sec;
^
cc1: all warnings being treated as errors
make[2]: *** [symfile.o] Error 1
make[2]: Leaving directory `gdb/gdb'
While the bug was reported to GCC as
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64823>,
the attached patch simply initializes sec with NULL.
gdb/ChangeLog:
* symfile.c (unmap_overlay_command): Initialize sec to NULL.
Tested on x86_64-linux.
gdb/ChangeLog:
* NEWS: Mention gdb.Objfile.username.
* python/py-objfile.c (objfpy_get_username): New function.
(objfile_getset): Add "username".
gdb/doc/ChangeLog:
* python.texi (Objfiles In Python): Document Objfile.username.
gdb/testsuite/ChangeLog:
* gdb.python/py-objfile.exp: Add tests for objfile.username.
Add test for objfile.filename, objfile.username after objfile
has been unloaded.
This further improves this testcase to check the output of
our calls to gdb.lookup_type.
gdb/ChangeLog:
* gdb.python/py-lookup-type.exp (test_lookup_type): Change
the second test to print the name attribute of value
returned by the call to gdb.lookup_type, and adjust
the expected output accordingly.
GCC5 defaults to the GNU11 standard for C and warns by default for
implicit function declarations and implicit return types.
https://gcc.gnu.org/gcc-5/porting_to.html
Fixing these issues in the testsuite turns 9 untested and 17 unsupported
testcases into 417 new passes when compiling with GCC5.
gdb/testsuite/ChangeLog:
* gdb.arch/i386-bp_permanent.c (standard): New declaration.
* gdb.base/disp-step-fork.c: Include unistd.h.
* gdb.base/siginfo-obj.c: Include stdio.h.
* gdb.base/siginfo-thread.c: Likewise.
* gdb.mi/non-stop.c: Include unistd.h.
* gdb.mi/nsthrexec.c: Include stdio.h.
* gdb.mi/pthreads.c: Include unistd.h.
* gdb.modula2/unbounded1.c (main): Declare returns int.
* gdb.reverse/consecutive-reverse.c: Likewise.
* gdb.threads/create-fail.c: Include unistd.h.
* gdb.threads/killed.c: Likewise.
* gdb.threads/linux-dp.c: Likewise.
* gdb.threads/non-ldr-exc-1.c: Include stdio.h and string.h.
* gdb.threads/non-ldr-exc-2.c: Likewise.
* gdb.threads/non-ldr-exc-3.c: Likewise.
* gdb.threads/non-ldr-exc-4.c: Likewise.
* gdb.threads/pthreads.c: Include unistd.h.
(main): Declare returns int.
* gdb.threads/tls-main.c (foo): New declaration.
* gdb.threads/watchpoint-fork-mt.c: Define _GNU_SOURCE.
Since Fedora started to use DWZ DWARF compressor:
http://fedoraproject.org/wiki/Features/DwarfCompressor
GDB has slowed down a lot. To make it clear - DWZ is DWARF structure
rearrangement, "compressor" does not mean any zlib style data compression.
This patch reduces LibreOffice backtrace from 5 minutes to 3 seconds (100x)
and it also reduces memory consumption 20x.
[ benchmark is at the bottom of this mail ]
Example of DWZ output:
------------------------------------------------------------------------------
Compilation Unit @ offset 0xc4:
<0><cf>: Abbrev Number: 17 (DW_TAG_partial_unit)
<d0> DW_AT_stmt_list : 0x0
<d4> DW_AT_comp_dir : (indirect string, offset: 0x6f): /usr/src/debug/gdb-7.7.1/build-x86_64-redhat-linux-gnu/gdb
<1><d8>: Abbrev Number: 9 (DW_TAG_typedef)
<d9> DW_AT_name : (indirect string, offset: 0x827dc): size_t
<dd> DW_AT_decl_file : 4
<de> DW_AT_decl_line : 212
<df> DW_AT_type : <0xae>
Compilation Unit @ offset 0xe4:
<0><ef>: Abbrev Number: 13 (DW_TAG_partial_unit)
<f0> DW_AT_stmt_list : 0x0
<f4> DW_AT_comp_dir : (indirect string, offset: 0x6f): /usr/src/debug/gdb-7.7.1/build-x86_64-redhat-linux-gnu/gdb
<1><f8>: Abbrev Number: 45 (DW_TAG_typedef)
<f9> DW_AT_name : (indirect string, offset: 0x251): __off_t
<fd> DW_AT_decl_file : 3
<fe> DW_AT_decl_line : 131
<ff> DW_AT_type : <0x68>
Compilation Unit @ offset 0x62d9f9:
<0><62da04>: Abbrev Number: 20 (DW_TAG_compile_unit)
[...]
<62da12> DW_AT_low_pc : 0x807e10
<62da1a> DW_AT_high_pc : 134
<62da1c> DW_AT_stmt_list : 0xf557e
<1><62da20>: Abbrev Number: 7 (DW_TAG_imported_unit)
<62da21> DW_AT_import : <0xcf> [Abbrev Number: 17]
------------------------------------------------------------------------------
One can see all DW_TAG_partial_unit have DW_AT_stmt_list 0x0 which causes
repeated decoding of that .debug_line unit on each DW_TAG_imported_unit.
This was OK before as each DW_TAG_compile_unit has its own .debug_line unit.
But since the introduction of DW_TAG_partial_unit by DWZ one should cache
read-in DW_AT_stmt_list .debug_line units.
Fortunately one does not need to cache whole
struct linetable *symtab->linetable
and other data from .debug_line mapping PC<->lines
------------------------------------------------------------------------------
Line Number Statements:
Extended opcode 2: set Address to 0x45c880
Advance Line by 25 to 26
Copy
------------------------------------------------------------------------------
as the only part of .debug_line which GDB needs for DW_TAG_partial_unit is:
------------------------------------------------------------------------------
The Directory Table:
../../gdb
/usr/include/bits
[...]
The File Name Table:
Entry Dir Time Size Name
1 1 0 0 gdb.c
2 2 0 0 string3.h
[...]
------------------------------------------------------------------------------
specifically referenced in GDB for DW_AT_decl_file at a single place:
------------------------------------------------------------------------------
fe = &cu->line_header->file_names[file_index - 1];
SYMBOL_SYMTAB (sym) = fe->symtab;
------------------------------------------------------------------------------
This is because for some reason DW_TAG_partial_unit never contains PC-related
DWARF information. I do not know exactly why, the compression ratio is a bit
lower due to it but thanksfully currently it is that way:
dwz.c:
------------------------------------------------------------------------------
/* These attributes reference code, prevent moving
DIEs with them. */
case DW_AT_low_pc:
case DW_AT_high_pc:
case DW_AT_entry_pc:
case DW_AT_ranges:
die->die_ck_state = CK_BAD;
+
/* State of checksum computation. Not computed yet, computed and
suitable for moving into partial units, currently being computed
and finally determined unsuitable for moving into partial units. */
enum { CK_UNKNOWN, CK_KNOWN, CK_BEING_COMPUTED, CK_BAD } die_ck_state : 2;
------------------------------------------------------------------------------
I have also verified also real-world Fedora debuginfo files really comply with
that assumption with dwgrep
https://github.com/pmachata/dwgrep
using:
------------------------------------------------------------------------------
dwgrep -e 'entry ?DW_TAG_partial_unit child* ( ?DW_AT_low_pc , ?DW_AT_high_pc , ?DW_AT_ranges )' /usr/lib/debug/**
------------------------------------------------------------------------------
BTW I think GDB already does not support the whole DW_TAG_imported_unit and
DW_TAG_partial_unit usage possibilities as specified by the DWARF standard.
I think GDB would not work if DW_TAG_imported_unit was used in some inner
level and not at the CU level (readelf -wi level <1>) - this is how DWZ is
using DW_TAG_imported_unit. Therefore I do not think further assumptions
about DW_TAG_imported_unit and DW_TAG_partial_unit usage by DWZ are a problem
for GDB.
One could save the whole .debug_line decoded PC<->lines mapping (and not just
the DW_AT_decl_file table) but:
* there are some problematic corner cases so one could do it incorrectly
* there are no real world data to really test such patch extension
* such extension could be done perfectly incrementally on top of this patch
------------------------------------------------------------------------------
benchmark - on Fedora 20 x86_64 and FSF GDB HEAD:
echo -e 'thread apply all bt\nset confirm no\nq'|./gdb -p `pidof soffice.bin` -ex 'set pagination off' -ex 'maintenance set per-command
space' -ex 'maintenance set per-command symtab' -ex 'maintenance set per-command time'
FSF GDB HEAD ("thread apply all bt"):
Command execution time: 333.693000 (cpu), 335.587539 (wall)
---sec
Space used: 1736404992 (+1477189632 for this command)
----MB
vs.
THIS PATCH ("thread apply all bt"):
Command execution time: 2.595000 (cpu), 2.607573 (wall)
-sec
Space used: 340058112 (+85917696 for this command)
--MB
FSF GDB HEAD ("thread apply all bt full"):
Command execution time: 466.751000 (cpu), 468.345837 (wall)
---sec
Space used: 2330132480 (+2070974464 for this command)
----MB
vs.
THIS PATCH ("thread apply all bt full"):
Command execution time: 18.907000 (cpu), 18.964125 (wall)
--sec
Space used: 364462080 (+110325760 for this command)
---MB
------------------------------------------------------------------------------
gdb/ChangeLog
2015-01-24 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix 100x slowdown regression on DWZ files.
* dwarf2read.c (struct dwarf2_per_objfile): Add line_header_hash.
(struct line_header): Add offset and offset_in_dwz.
(dwarf_decode_lines): Add parameter decode_mapping to the declaration.
(free_line_header_voidp): New declaration.
(line_header_hash, line_header_hash_voidp, line_header_eq_voidp): New
functions.
(dwarf2_build_include_psymtabs): Update dwarf_decode_lines caller.
(handle_DW_AT_stmt_list): Use line_header_hash.
(free_line_header_voidp): New function.
(dwarf_decode_line_header): Initialize offset and offset_in_dwz.
(dwarf_decode_lines): New parameter decode_mapping, use it.
(dwarf2_free_objfile): Free line_header_hash.
In the situation described in bug 17416 [1]:
* "set print object" is on;
* The variable object is a pointer to a struct, and it contains an
invalid value (e.g. NULL, or random uninitialized value);
* The variable object (struct) has a child which is also a pointer to a
struct;
* We try to use "-var-list-children".
... an exception thrown in value_ind can propagate too far and leave an
half-built variable object, leading to a wrong state. This patch adds a
TRY_CATCH to catch it and makes value_rtti_indirect_type return NULL in
that case, meaning that the type of the pointed object could not be
found.
A test for the fix is also added.
New in v2:
* Added test.
* Restructured "catch" code.
* Added details about the bug in commit log.
gdb/Changelog:
* valops.c (value_rtti_indirect_type): Catch exception thrown by
value_ind.
gdb/testsuite/ChangeLog
* gdb.mi/mi-var-list-children-invalid-grandchild.c: New file.
* gdb.mi/mi-var-list-children-invalid-grandchild.exp: New file.
[1] https://sourceware.org/bugzilla/show_bug.cgi?id=17416
Add a flag field is_noreturn to struct func_type. Make calling_convention
a small bit field to not increase the size of the struct. Set is_noreturn
if the new GCC5/DWARF5 DW_AT_noreturn is set on a DW_TAG_subprogram.
Use this information to warn the user before doing a finish or return from
a function that does not return normally to its caller.
(gdb) finish
warning: Function endless does not return normally.
Try to finish anyway? (y or n)
(gdb) return
warning: Function does not return normally to caller.
Make endless return now? (y or n)
gdb/ChangeLog
* dwarf2read.c (read_subroutine_type): Set TYPE_NO_RETURN from
DW_AT_noreturn.
* gdbtypes.h (struct func_type): Add is_noreturn field flag. Make
calling_convention an 8 bit bit field.
(TYPE_NO_RETURN): New macro.
* infcmd.c (finish_command): Query if function does not return
normally.
* stack.c (return_command): Likewise.
gdb/testsuite/ChangeLog
* gdb.base/noreturn-return.c: New file.
* gdb.base/noreturn-return.exp: New file.
* gdb.base/noreturn-finish.c: New file.
* gdb.base/noreturn-finish.exp: New file.
include/ChangeLog
* dwarf2.def (DW_AT_noreturn): New DWARF5 attribute.
The dwarf2.h addition and the code to emit the new attribute is already in
the gcc tree.
linux_nat_is_async_p currently always returns true, even when the
target is _not_ async. That confuses
gdb_readline_wrapper/gdb_readline_wrapper_cleanup, which
force-disables target-async while the secondary prompt is active. As
a result, when gdb_readline_wrapper returns, the target is left async,
even through it was sync to begin with.
That can result in weird bugs, like the one the test added by this
commit exposes.
Ref: https://sourceware.org/ml/gdb-patches/2015-01/msg00592.html
gdb/ChangeLog:
2015-01-23 Pedro Alves <palves@redhat.com>
* linux-nat.c (linux_is_async_p): New macro.
(linux_nat_is_async_p):
(linux_nat_terminal_inferior): Check whether the target can async
instead of whether it is already async.
(linux_nat_terminal_ours): Don't check whether the target is
async.
(linux_async_pipe): Use linux_is_async_p.
gdb/testsuite/ChangeLog:
2015-01-23 Pedro Alves <palves@redhat.com>
* gdb.threads/continue-pending-after-query.c: New file.
* gdb.threads/continue-pending-after-query.exp: New file.
gdb_interact is a small utility that we have found quite useful to debug
test cases.
Putting gdb_interact in a test suspends it and allows to interact with
gdb to inspect whatever you want. You can then type ">>>" to resume the
test execution. Of course, this is only for gdb devs. It wouldn't make
sense to leave a gdb_interact permanently in a test case.
When starting the interaction with the user, the script prints this
banner:
+------------------------------------------+
| Script interrupted, you can now interact |
| with by gdb. Type >>> to continue. |
+------------------------------------------+
Notes:
* When gdb is launched, the gdb_spawn_id variable (lib/gdb.exp) is
assigned -1. Given the name, I would expect it to contain the gdb
expect spawn id, which is needed for interact. I changed all places
that set gdb_spawn_id to -1 to set it to the actual gdb spawn id
instead.
* When entering the "interact" mode, the last (gdb) prompt is already
eaten by expect, so it doesn't show up on the terminal. Subsequent
prompts do appear though. We tried to print "(gdb)" just before the
interact to replace it. However, it could be misleading if you are
debugging an MI test case, it makes you think that you are typing in a
CLI prompt, when in reality it's MI. In the end I decided that since
the feature is for developers who know what they're doing and that one
is normally consciously using gdb_interact, the script doesn't need
to babysit the user.
* There are probably some quirks depending on where in the script
gdb_interact appears (e.g. it could interfere with following
commands and make them fail), but it works for most cases. Quirks can
always be fixed later.
The idea and original implementation was contributed by Anders
Granlund, a colleague of mine. Thanks to him.
gdb/testsuite/ChangeLog:
* gdb.base/statistics.exp: Assign spawn id to gdb_spawn_id.
* gdb.base/valgrind-db-attach.exp: Same.
* gdb.base/valgrind-infcall.exp: Same.
* lib/mi-support.exp (default_mi_gdb_start): Same.
* lib/prompt.exp (default_prompt_gdb_start): Same.
* lib/gdb.exp (default_gdb_spawn): Same.
(gdb_interact): New.
downstream Fedora request:
Please make it easier to find the backtrace of the crashing thread
https://bugzilla.redhat.com/show_bug.cgi?id=1024504
Currently after loading a core file GDB prints:
Core was generated by `./threadcrash1'.
Program terminated with signal SIGSEGV, Segmentation fault.
8 *(volatile int *)0=0;
(gdb) _
there is nowhere seen which of the threads had crashed. In reality GDB always
numbers that thread as #1 and it is the current thread that time. But after
dumping all the info into a file for later analysis it is no longer obvious.
'thread apply all bt' even puts the thread #1 to the _end_ of the output!!!
I find maybe as good enough and with no risk of UI change flamewar to just
sort the threads by their number. Currently they are printed as they happen
in the internal GDB list which has no advantage. Printing thread #1 as the
first one with assumed 'thread apply all bt' (after the core file is loaded)
should make the complaint resolved I guess.
On Thu, 15 Jan 2015 20:29:07 +0100, Doug Evans wrote:
No objection to sorting the list, but if thread #1 is the important one,
then a concern could be it'll have scrolled off the screen (such a
concern has been voiced in another thread in another context),
and if not lost (say it's in an emacs buffer) one would still have
to scroll back to see it.
So one *could* still want #1 to be last.
Do we want an option to choose the sort direction?
gdb/ChangeLog
2015-01-22 Jan Kratochvil <jan.kratochvil@redhat.com>
* NEWS (Changes since GDB 7.9): Add 'thread apply all' option
'-ascending'.
* thread.c (tp_array_compar_ascending, tp_array_compar): New.
(thread_apply_all_command): Parse CMD for tp_array_compar_ascending.
Sort tp_array using tp_array_compar.
(_initialize_thread): Extend thread_apply_all_command help.
gdb/doc/ChangeLog
2015-01-22 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.texinfo (Threads): Describe -ascending for thread apply all.
downstream Fedora request:
Please make it easier to find the backtrace of the crashing thread
https://bugzilla.redhat.com/show_bug.cgi?id=1024504
Currently after loading a core file GDB prints:
Core was generated by `./threadcrash1'.
Program terminated with signal SIGSEGV, Segmentation fault.
8 *(volatile int *)0=0;
(gdb) _
there is nowhere seen which of the threads had crashed. In reality GDB always
numbers that thread as #1 and it is the current thread that time. But after
dumping all the info into a file for later analysis it is no longer obvious.
'thread apply all bt' even puts the thread #1 to the _end_ of the output!!!
Should GDB always print after loading a core file what "thread" command would
print?
[Current thread is 1 (Thread 0x7fcbe28fe700 (LWP 15453))]
BTW I think it will print the thread even when loading single/non-threaded
core file when other inferior(s) exist. But that currently crashes
[Bug threads/12074] multi-inferior internal error
https://sourceware.org/bugzilla/show_bug.cgi?id=12074
plus I think that would be a correct behavior anyway.
gdb/ChangeLog
2015-01-22 Jan Kratochvil <jan.kratochvil@redhat.com>
* corelow.c (core_open): Call also thread_command.
* gdbthread.h (thread_command): New prototype moved from ...
* thread.c (thread_command): ... here.
(thread_command): Make it global.
When GDB is configured with "--without-tui --with-curses" or "--with-tui",
$prefer_curses is set to yes. But, that still doesn't mean that curses
will be used. configure will still search for the curses library, and
continue building without it. That's done here:
curses_found=no
if test x"$prefer_curses" = xyes; then
...
AC_SEARCH_LIBS(waddstr, [ncurses cursesX curses])
if test "$ac_cv_search_waddstr" != no; then
curses_found=yes
fi
fi
So if waddstr is not found, meaning curses is not really
available, even though it'd be preferred, $prefer_curses is
'yes', but $curses_found is 'no'.
So the right fix to tell whether we're linking with curses is
$curses_found=yes.
gdb/ChangeLog:
2015-01-22 Pedro Alves <palves@redhat.com>
* configure.ac [*mingw32*]: Check $curses_found instead of
$prefer_curses.
* configure: Regenerate.
* windows-termcap.c: Remove HAVE_CURSES_H, HAVE_NCURSES_H and
HAVE_NCURSES_NCURSES_H checks.
gdb/
2015-01-22 Eli Zaretskii <eliz@gnu.org>
* gdb/tui/tui.c (tui_enable) [__MINGW32__]: If the call to 'newterm'
fails with the 1st arg NULL, try again with "unknown". Don't test
the "cup" capability: it isn't supported by the Windows port of
ncurses, but the Windows console driver is still capable of
supporting TUI.
TBH while I always comment reasons for each of the compilation options in
reality I tried them all and chose that combination that needs the most simple
compile/compile-object-load.c (ld.so emulation) implementation.
gdb/ChangeLog
2015-01-22 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile.c (_initialize_compile): Use -fPIE for compile_args.
gdb/testsuite/ChangeLog
2015-01-22 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile.exp (pointer to jit function): New test.
gdb/
2015-01-22 Eli Zaretskii <eliz@gnu.org>
* Makefile.in (HFILES_NO_SRCDIR): Remove ada-varobj.h.
(ALLDEPFILES): Remove irix5-nat.c. These two are part of the
reason that "make TAGS" is broken.
Original working flow has several issues:
- typo issue: "(inst >> 26) == 0x1f && ..." for checking 'stw(m)'.
- "(inst >> 6) == 0xa" needs to be "((inst >> 6) & 0xf) == 0xa".
And also need check additional store instructions:
- For absolute memory: 'stby', 'stdby'.
- For unaligned: 'stwa', 'stda'.
The original code also can be improved:
- Remove redundant double check "(inst >> 26) == 0x1b" for 'stwm'.
- Use 2 'switch' statements instead of all 'if' statements.
* hppa-tdep.c (inst_saves_gr): Fix logical working flow issues
and check additional store instructions.
gdb/
2015-01-17 Eli Zaretskii <eliz@gnu.org>
* configure.ac [*mingw32*]: Only add windows-termcap.o to
CONFIG_OBS if not building with a curses library.
* configure: Regenerate.
* windows-termcap.c: Include defs.h. Make the whole body empty if
either one of HAVE_CURSES_H or HAVE_NCURSES_H or
HAVE_NCURSES_NCURSES_H is defined.
This commit fixes the regression on RHEL-5 systems introduced by
nat/linux-personality.c's check of HAVE_DECL_ADDR_NO_RANDOMIZE.
RHEL-5 systems define HAVE_DECL_ADDR_NO_RANDOMIZE as zero, so we
cannot use #ifndef; instead this patch uses the "#if !" construction.
The regression was reported by Ulrich Weigand here:
<https://sourceware.org/ml/gdb-patches/2015-01/msg00458.html>
gdb/ChangeLog
2015-01-16 Sergio Durigan Junior <sergiodj@redhat.com>
* nat/linux-personality.c: Replace "#ifndef
HAVE_DECL_ADDR_NO_RANDOMIZE" by "#if
!HAVE_DECL_ADDR_NO_RANDOMIZE", fixing a regression in RHEL-5
systems.
gdb/
2015-01-16 Eli Zaretskii <eliz@gnu.org>
* tui/tui-win.c (tui_rehighlight_all, tui_set_var_cmd): New
functions.
(_initialize_tui_win) <border-kind, border-mode>:
<active-border-mode>: Use tui_set_var_cmd as the "set" function.
* tui/tui-win.h: Add prototype for tui_rehighlight_all.
gdb/ChangeLog:
2015-01-16 Eli Zaretskii <eliz@gnu.org>
* tui/tui-win.c (tui_set_tab_width_command): Delete and
recreate the source and the disassembly windows, to show the
effect of the changed tab size immediately.
tui/tui-win.c (tui_scroll_left_command, tui_scroll_right_command):
Doc fix.
doc/gdb.texinfo (TUI Commands): Document the possible
values of NAME argument to 'winheight' command. Explain the
effect of 'tabset' setting better.
gdb/tui/tui-data.h (LINE_PREFIX): Make shorter
(MAX_PID_WIDTH): Enlarge from 14 to 19, to leave enough space for
"Thread NNNNN.XXXX" thread ID notation on Windows.
With gcc-5.0 pre-release one gets:
hppa-tdep.c: In function ‘inst_saves_gr’:
hppa-tdep.c:1406:30: error: comparison of constant ‘9’ with boolean expression is always false [-Werror=bool-compare]
I find the misplaced parentheses obvious.
gdb/ChangeLog
2015-01-16 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix gcc-5 compilation.
* hppa-tdep.c (inst_saves_gr): Fix parentheses typo.
This patch moves the shared code present on
gdb/linux-nat.c:linux_nat_create_inferior and
gdb/gdbserver/linux-low.c:linux_create_inferior to
nat/linux-personality.c. This code is responsible for disabling
address space randomization based on user setting, and using
<sys/personality.h> to do that. I decided to put the prototype of the
maybe_disable_address_space_randomization on nat/linux-osdata.h
because it seemed the best place to put it.
I regression-tested this patch on Fedora 20 x86_64, and found no
regressions.
gdb/ChangeLog
2015-01-15 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in (HFILES_NO_SRCDIR): Add nat/linux-personality.h.
(linux-personality.o): New rule.
* common/common-defs.h: Include <stdint.h>.
* config/aarch64/linux.mh (NATDEPFILES): Include
linux-personality.o.
* config/alpha/alpha-linux.mh (NATDEPFILES): Likewise.
* config/arm/linux.mh (NATDEPFILES): Likewise.
* config/i386/linux64.mh (NATDEPFILES): Likewise.
* config/i386/linux.mh (NATDEPFILES): Likewise.
* config/ia64/linux.mh (NATDEPFILES): Likewise.
* config/m32r/linux.mh (NATDEPFILES): Likewise.
* config/m68k/linux.mh (NATDEPFILES): Likewise.
* config/mips/linux.mh (NATDEPFILES): Likewise.
* config/pa/linux.mh (NATDEPFILES): Likewise.
* config/powerpc/linux.mh (NATDEPFILES): Likewise.
* config/powerpc/ppc64-linux.mh (NATDEPFILES): Likewise.
* config/powerpc/spu-linux.mh (NATDEPFILES): Likewise.
* config/s390/linux.mh (NATDEPFILES): Likewise.
* config/sparc/linux64.mh (NATDEPFILES): Likewise.
* config/sparc/linux.mh (NATDEPFILES): Likewise.
* config/tilegx/linux.mh (NATDEPFILES): Likewise.
* config/xtensa/linux.mh (NATDEPFILES): Likewise.
* defs.h: Remove #include <stdint.h> (moved to
common/common-defs.h).
* linux-nat.c: Include nat/linux-personality.h. Remove #include
<sys/personality.h>; do not define ADDR_NO_RANDOMIZE (moved to
nat/linux-personality.c).
(linux_nat_create_inferior): Remove code to disable address space
randomization (moved to nat/linux-personality.c). Create cleanup
to disable address space randomization.
* nat/linux-personality.c: New file.
* nat/linux-personality.h: Likewise.
gdb/gdbserver/ChangeLog
2015-01-15 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in (SFILES): Add linux-personality.c.
(linux-personality.o): New rule.
* configure.srv (srv_linux_obj): Add linux-personality.o to the
list of objects to be built.
* linux-low.c: Include nat/linux-personality.h.
(linux_create_inferior): Remove code to disable address space
randomization (moved to ../nat/linux-personality.c). Create
cleanup to disable address space randomization.