Had to be a big sweeping change, but the regression tests shows just
improvements :-)
Now we stop using an id in struct tag, only storing the type, that now
uses 16 bits only, as CTF does.
Each format loader has to go on adding the types to the core, that
figures out if it is a tag that can be on the tag->type field
(tag__is_tag_type).
Formats that already have the types separated and in sequence, such as
CTF, just ask the core to insert in the types_table directly with its
original ID.
For DWARF, we ask the core to put it on the table, in sequence, and return the
index, that is then stashed with the DWARF specific info (original id, type,
decl_line, etc) and hashed by the original id. Later we recode everything,
looking up via the original type, getting the small_id to put on the tag->type.
The underlying debugging info not needed by the core is stashed in tag->priv,
and the DWARF loader now just allocates sizeof(struct dwarf_tag) at the end of
the core tag and points it there, and makes that info available thru
cu->orig_info. In the future we can ask, when loading a cu, that this info be
trown away, so that we reduce the memory footprint for big multi-cu files such
as the Linux kernel.
There is also a routine to ask for inserting a NULL, as we still have
bugs in the CTF decoding and thus some entries are being lost, to avoid
using an undefined pointer when traversing the types_table the ctf
loader puts a NULL there via cu__table_nullify_type_entry() and then
cu__for_each_type skips those.
There is some more cleanups for leftovers that I avoided cleaning to
reduce this changeset.
And also while doing this I saw that enums can appear without any
enumerators and that an array with DW_TAG_GNU_vector is actually a
different tag, encoded this way till we get to DWARF4 ;-)
So now we don't have to lookup on a hash table looking for DWARF
offsets, we can do the more sensible thing of just indexing the
types_tags array.
Now to do some cleanups and try to get the per cu encoder done. Then
order all the cus per number of type entries, pick the one with more,
then go on merging/recoding the types of the others and putting the
parent linkage in place.
Just to show the extent of the changes:
$ codiff /tmp/libdwarves.so.1.0.0 build/libdwarves.so.1.0.0
/home/acme/git/pahole/dwarves.c:
struct cu | -4048
struct tag | -32
struct ptr_to_member_type | -32
struct namespace | -32
struct type | -32
struct class | -32
struct base_type | -32
struct array_type | -32
struct class_member | -32
struct lexblock | -32
struct ftype | -32
struct function | -64
struct parameter | -32
struct variable | -32
struct inline_expansion | -32
struct label | -32
struct enumerator | -32
17 structs changed
tag__follow_typedef | +3
tag__fprintf_decl_info | +25
array_type__fprintf | +6
type__name | -126
type__find_first_biggest_size_base_type_member | -3
typedef__fprintf | +16
imported_declaration__fprintf | +6
imported_module__fprintf | +3
cu__new | +26
cu__delete | +26
hashtags__hash | -65
hash_64 | -124
hlist_add_head | -78
hashtags__find | -157
cu__hash | -80
cu__add_tag | +20
tag__prefix | -3
cu__find_tag_by_id | -2
cu__find_type_by_id | -3
cu__find_first_typedef_of_type | +38
cu__find_base_type_by_name | +68
cu__find_base_type_by_name_and_size | +72
cu__find_struct_by_name | +59
cus__find_struct_by_name | +8
cus__find_tag_by_id | +5
cus__find_cu_by_name | -6
lexblock__find_tag_by_id | -173
cu__find_variable_by_id | -197
list__find_tag_by_id | -308
cu__find_parameter_by_id | -60
tag__ptr_name | +6
tag__name | +15
variable__type | +13
variable__name | +7
class_member__size | +6
parameter__name | -119
tag__parameter | -14
parameter__type | -143
type__fprintf | -29
union__fprintf | +6
class__add_vtable_entry | -9
type__add_member | -6
type__clone_members | -3
enumeration__add | -6
function__name | -156
ftype__has_parm_of_type | -39
class__find_holes | -27
class__has_hole_ge | -3
type__nr_members_of_type | +3
lexblock__account_inline_expansions | +3
cu__account_inline_expansions | -18
ftype__fprintf_parms | +46
function__tag_fprintf | +24
lexblock__fprintf | -6
ftype__fprintf | +3
function__fprintf_stats | -18
function__size | -6
class__vtable_fprintf | -11
class__fprintf | -21
tag__fprintf | -35
60 functions changed, 513 bytes added, 2054 bytes removed, diff: -1541
/home/acme/git/pahole/ctf_loader.c:
struct ctf_short_type | +0
14 structs changed
type__init | -14
type__new | -9
class__new | -12
create_new_base_type | -7
create_new_base_type_float | -7
create_new_array | -8
create_new_subroutine_type | -9
create_full_members | -18
create_short_members | -18
create_new_class | +1
create_new_union | +1
create_new_enumeration | -19
create_new_forward_decl | -2
create_new_typedef | +3
create_new_tag | -5
load_types | +16
class__fixup_ctf_bitfields | -3
17 functions changed, 21 bytes added, 131 bytes removed, diff: -110
/home/acme/git/pahole/dwarf_loader.c:
17 structs changed
zalloc | -56
tag__init | +3
array_type__new | +20
type__init | -24
class_member__new | +46
inline_expansion__new | +12
class__new | +81
lexblock__init | +19
function__new | +43
die__create_new_array | +20
die__create_new_parameter | +4
die__create_new_label | +4
die__create_new_subroutine_type | +113
die__create_new_enumeration | -21
die__process_class | +79
die__process_namespace | +76
die__create_new_inline_expansion | +4
die__process_function | +147
__die__process_tag | +34
die__process_unit | +56
die__process | +90
21 functions changed, 851 bytes added, 101 bytes removed, diff: +750
/home/acme/git/pahole/dwarves.c:
struct ptr_table | +16
struct cu_orig_info | +32
2 structs changed
tag__decl_line | +68
tag__decl_file | +70
tag__orig_id | +71
ptr_table__init | +46
ptr_table__exit | +37
ptr_table__add | +183
ptr_table__add_with_id | +165
ptr_table__entry | +64
cu__table_add_tag | +171
cu__table_nullify_type_entry | +38
10 functions changed, 913 bytes added, diff: +913
/home/acme/git/pahole/ctf_loader.c:
2 structs changed
tag__alloc | +52
1 function changed, 52 bytes added, diff: +52
/home/acme/git/pahole/dwarf_loader.c:
struct dwarf_tag | +48
struct dwarf_cu | +4104
4 structs changed
dwarf_cu__init | +83
hashtags__hash | +61
hash_64 | +124
hlist_add_head | +78
hashtags__find | +161
cu__hash | +95
tag__is_tag_type | +171
tag__is_type | +85
tag__is_union | +28
tag__is_struct | +57
tag__is_typedef | +28
tag__is_enumeration | +28
dwarf_cu__find_tag_by_id | +56
dwarf_cu__find_type_by_id | +63
tag__alloc | +114
__tag__print_type_not_found | +108
namespace__recode_dwarf_types | +346
tag__namespace | +14
tag__has_namespace | +86
tag__is_namespace | +28
type__recode_dwarf_specification | +182
tag__type | +14
__tag__print_abstract_origin_not_found | +105
ftype__recode_dwarf_types | +322
tag__ftype | +14
tag__parameter | +14
lexblock__recode_dwarf_types | +736
tag__lexblock | +14
tag__label | +14
tag__recode_dwarf_type | +766
tag__ptr_to_member_type | +14
cu__recode_dwarf_types_table | +88
cu__recode_dwarf_types | +48
dwarf_tag__decl_file | +77
strings__ptr | +33
dwarf_tag__decl_line | +59
dwarf_tag__orig_id | +59
dwarf_tag__orig_type | +59
38 functions changed, 4432 bytes added, diff: +4432
build/libdwarves.so.1.0.0:
147 functions changed, 6782 bytes added, 2286 bytes removed, diff: +4496
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Do nothing for now, just to reduce the size of the upcoming
type recoding patch, aka dwarves undwarvification.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
By avoiding tsearch calls, checking if the decl_file for the current tag
is the same for the last one, which is likely.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Grrr, the previous commit has the other bits, and as I already pushed it
out publicly... <BROWN PAPER BAG ALERT!> here goes the rests. So much
for bissectability. Sigh.
But the regression test showed only one problem, in C++ code, that I'll
fix in the next commits.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that we can then decide in what hashtable we will add it, and this
also paves the way for a type array that will help us in reducing the
size of struct tag by removing the id field.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
And comment the difference to tag__is_type:
tag__is_type == is this tag derived from the 'type' class?
tag__is_tag_type == is this tag a possible type for a tag, i.e.
one we will find in struct tag->type?
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Consider this case:
$ codiff -V /tmp/pahole.old build/pahole
/home/acme/git/pahole/pahole.c:
struct tag | +0
refcnt
removed: uint16_t /* 56( 0) 2( 0) */
recursivity_level
from: uint16_t /* 58( 0) 2( 0) */
to: uint16_t /* 56( 0) 2(15) */
used
added: uint16_t /* 56(15) 2( 1) */
1 struct changed
The number of members is the same and so is the size of the struct, but
'refcnt' was removed (in fact renamed to used) and 'used' was added.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Unfortunately the most common DWARF and CTF encoders don't agree on how
the names of base types are formed, so look for an alternative name.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As most of the types comes with it already. Perhaps this was an
oversight and we will have to look if the name already has "char",
concat'ing only if it doesn't. We'll see...
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The dwarves were implemented first for DWARF, so all the algorithms work
with class_member ->bit_size, ->bit_offset and expect the ->offset field
to be the same for all members of a bitfield, so fixup these fields
after loading a CTF section.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Needed for CTF, where we can have many base types with name "unsigned",
but with different bit sizes, to implement bitfields.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now we just pass a NULL terminated array of filenames, since we got rid
of that ugly -e insertion hack.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now we use dwfl_report_offline directly, having more control about the
whole process, not using anymore dwfl_standard_argp.
This also, semi magicly, makes it work with the built-in.o files
in the Linux kernel, that aggregates multiple object files and that
previously were failing with relocation problems.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This is still ugly, as the processing of argp was done on the loader so
that we can use the libdwfl argp processing, doing the tool argp
processing as a child. But then when we find out that there is no DWARF
info we fall back to another debugging format, with CTF being the only
other one supported as of now.
I used this scheme as when developing the CTF decoder and using pahole
on a binary with both CTF and DWARF info I would like to get the CTF
processed first.
So we still need some good refactoring here to get this sorted out in a
way that the user can specify the order of decoding, and perhaps even
ask for decoding _both_ and comparing if the results are the same, i.e.
if the (potentially subset of) information decoded from the first (that
may have less information: CTF) is the same as decoded from the second
(DWARF, more verbose).
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that they appear on the output in the same order as they
come from the original debugging info.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
And make the dwarves use it, so that we can remove duplicate strings in
a multi-CU file (vmlinux anyone?) and have it ready for insertion in a
compressed DWARF format with just the types, or better, CTF or some new
compressed debugging info format.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Arnaldo Carvalho de Melo