Remove the global variable and turn it into a member in struct
conf_fprintf, so that it can be used by other parts of the code.
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
Cc: dwarves@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since we don't need the cu to get the strings table, all tags have a
char pointer for strings.
Found while building with clang to prep 1.22.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since we don't need the cu to get the strings table, all tags have a
char pointer for strings.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For the threaded code we want to access strings in tags at the same time
that the string table may grow in another thread making the previous
pointer invalid, so, to avoid excessive locking, use plain strings.
The way the tools work will either consume the just produced CU straight
away or keep just one copy of each data structure when we keep all CUs
in memory, so lets try stopping using strings_t for strings.
For the class_member->name case we get the bonus of removing another
user of dwarves__active_loader.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Andrii reported that __unused is a field in /usr/include/bits/stat.h and
vmlinux.h (generated by bpftool), so use the Linux kernel jargon for
this and rename it to '__maybe_unused'.
Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
I changed the logic at some point stopping the use of that variable, but
then forgot to remove it, do it now.
Addresses this coverity report entry:
Error: COMPILER_WARNING: [#def3]
dwarves-1.13/codiff.c: scope_hint: In function 'main'
dwarves-1.13/codiff.c:776:8: warning: variable 'filenames' set but not used [-Wunused-but-set-variable]
# 776 | char *filenames[2];
# | ^~~~~~~~~
# 774| int remaining, err, rc = EXIT_FAILURE;
# 775| char *old_filename, *new_filename;
# 776|-> char *filenames[2];
# 777| struct stat st;
# 778|
Need to find how to make cmake show these warnings...
Reported-by: William Cohen <wcohen@redhat.com>
Fixes: 991c6a3ebb ("dwarves: Rename cus__loadfl with cus__load_files")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When the first arg, the old object file has multiple compile units, i.e.
multiple objects that were then linked into one, and the second just one
.o, or equivalent, i.e. a .BTF file, then codiff shouldn't try to
find the types in the single CU in each of the old CUs.
Think about a .BTF file generated from a multi-CU DWARF binary, it will
contain all the types in all of the DWARF CUs, so if we go on trying to
find all the BTF files in each of the CUs, we'll fail.
It only makes sense to go on the DWARF CUs looking for the type on the
.BTF section and then compare them.
Fixes: 6b1e43f2c1 ("codiff: When comparing against a file with just one CU don't bother finding by name")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
I.e. 'union {};', 'struct {};' members were always appearing as having
been removed, as we normally do lookup by member name, to find out if
its offset, size, type, etc changed.
For unnamed members, try a different heuristic, i.e. look for the nth
anonymous member, this way we're just trying to compare the first
unnamed member of, say, struct OLD with the first unnamed member of
struct NEW, etc.
For OLD == NEW, this works well, for OLD != NEW because some non
anonymous field got added, removed or moved around, ditto, and when the
number of unnamed fields gets decreased, then we can mix things up, and
compare the previously first in A with the previously first in B.
For the current intended use case of:
1) compile a .c file into a .o file with debugging info, say FILE.o
2) use 'pfunct --compile FILE.o > regenerated-FILE.c'
3) compile regenerated-FILE.c into regenerated-FILE.o with debugging info
4) codiff --struct FILE.o regenerated-FILE.o and find out if they match
This gets us moving forward as we'll spot differences with this algo.
For the future we can use a few more heuristics or stop using search by
name members, instead traversing both structs in tandem, spotting the
differences by comparing the fields that way.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
I.e. when we have two object files with debugging info, and one of them
jas just one CU, then compare all the CUs in the other file to this
unique CU.
Case in hand: encode BTF in a file, then the BTF info has everything in
just one "compile unit", so when looking at the types in the DWARF
originals, we should just compare its types to what is in the single BTF
"compile unit".
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As Thomas Gleixner wisely pointed out, using 'self' is stupid, it
doesn't convey useful information, so use sensible names.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
That asks dwarf_fprintf to always use "struct" in places where it would
use "class", because CTF doesn't have the "class" concept, so for
'regtest diffctf' sake, we use this.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
I wasn't especifying the optimization level and the default, despite
using -Wall, was for this so simple case not to be warned about, so
now I'm using -O2.
Alexandre provided a patch initializing the variables to NULL, so that
when we called cus__delete it would bail out and not possibly act on
a random value, I preferred to add extra goto labels and do the exit
path only on the resources that were successfully allocated/initialized,
avoiding, for instance, to call dwarves_exit() if dwarves_init() wasn't
called, which wasn't a problem so far, but could be in the future.
Reported-by: Alexandre Vassalotti <alexandre@peadrop.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There is still the problem of handing the strings table to the CTF encoder, but
that will be fixed another day.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Instead pass thru cu__strings(cu, i) so that we can figure out if the
underlying debugging format handler can do that more efficiently, such as by
looking up directly the ELF section ".strtab".
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Just use cu__for_each_struct and cu__for_each_function, newer functions that
are more appropriate and make the code more easy to follow.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Because we already use ctf__load in libctf.c, rename the others to
disambiguate, and also as there are the __load_dir and __load_files
it looks more consistent.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To shorten the name and to reflect the fact that we're no longer
"finding" a type, but merely accessing an array with a bounds check in
this function.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This will help us in the next csets when we need to know both the full
size of the base_type used in an bitfield _and_ the size in bits of the
bitfield member.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Because we will need the "bit_offset" and "bit_size" names when converting the
representation of offset and size everywhere to be in bits, not bytes.
At the same time we will keep bitfield_size and bitfield_offset when we convert
from DWARF to CTF and will calculate them when loading CTF, so that the
conversion of the algorithms in dwarves_reorganize, that have all sorts of
subtle issues, can be left for later.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Amazing how many crept up over time, should have set the
execute bit of .git/hooks/pre-commit already, duh.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Also introducing cus__load, that load just one file.
The new cus__load_files routine now iterates thru the provided array
calling cus__load for each, and that in turn will try first dwarf__load,
and if that fail, i.e. if no DWARF info is found, call ctf__load.
This now allows loading DWARF _and_ CTF files at the same time. This
will be useful in the future when we, from DWARF generate CTF and at the
same time do a codiff, comparing the freshly generated CTF file with the
DWARF it came from.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that, when not needing the DWARF info, the apps can tell that at load
time, and then the dwarf loader can just free all the dwarf_tags
allocated, reducing memory usage.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To take advantage of cache effects and to avoid calling cu__find_holes
more than once on the same struct.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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>
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>
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>
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>
Douglas Raillard
Arnaldo Carvalho de Melo
Domenico Andreoli