And not compare by string_t, as now it may not be on the global strings table,
so we have to give a chance to the underlying debug format to translate that to
a string for us.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In the paste we ass-umed that if cu->dfops != NULL, all the methods would be
there, this ain't so anymore, so check it.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
That is done by adding some new struct debug_fmt_ops methods:
->function__name()
This one, if specified, will be called by function__name(), giving a chance to
formats such as CTF to get this from some other place than the global strings
table. CTF does this by storing GElf_Sym->st_name in function->name, and by
providing a dfops->function__name() that uses function->name as an index into
the .strtab ELF section.
->cu__delete()
This is needed because we can't anymore call ctf__delete at the end of
ctf__load_file, as we will need at least the .strstab ELF section to be
available till we're done with the cu, i.e. till we call cu__delete(), that now
calls dfops->cu__delete() if it is available.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There are more things that should be handled differently, such as function
names coming from the .strtab ELF section instead of from the global strings_t
table.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Temporary hack till I figure out how to do more filtering on the functions on
the symtab that aren't in the DWARF info.
Problem is that if we don't put something on the table at encode time, we won't
find it at decode time, when we don't have DWARF to notice that its not there
because its not in DWARF.
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>
To cover the case where there aren't structs or even any type at all.
It looks now just like cu__for_each_function, so its more consistent as a bonus
:-)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As we won't find them in CTF land... I also have to add a new pfunct cmdline
option to ask for inline functions not to be printed, as they aren't on the
symtab.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Till all the tags were processed, as in DWARF we can have class_member types
being defined _after_ them, so we don't find it when trying to recode
class_member at constructor time (class_member__new). Do it later after all the
types are hashed, in namespace__recode_dwarf_types.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We should do just as with typedefs, i.e. find the type these tags point to, and
create a new volatile/const tag pointing to the underlying bitfield tag.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Encoding all the non UNDEF OBJECT entries in the symtab. Some must be filtered
in upcoming patches, but for at least kernel/sched.o it works just fine.
To test it I used DaveM's ctfdump and also pdwtags on a --strip-debug, pahole
-Z CTF encoded object.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Will be used when encoding the OBJECT symtab entries in the
objects CTF section (varibles/data).
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For loaders to fill with the address of global variables.
More work is needed to cover relocation, registers, etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We need it to be able to call cu__for_each_cached_symtab_entry more
than once in the same function.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Finally we can use the Elf file already opened in dwarf_load, call
cu__for_each_cached_symtab_entry to iterate over the symtab entries,
this iterator will first call dwfl_module_getsymtab, that will do the
relocation that will allow us to go from the symtab address to the one
in the DWARF DW_TAG_subprogram tag DW_AT_low_pc attribute.
And voila, for a relatively complex single unit Linux kernel object
file, kernel/sched.o, we go from:
Just DWARF (gcc -g):
$ ls -la kernel/sched.o
1979011 kernel/sched.o
Then we run this to encode the CTF section:
$ pahole -Z kernel/sched.o
And get a file with both DWARF and CTF ELF sections:
$ ls -la kernel/sched.o
2019848 kernel/sched.o
We still need to encode the "OBJECTS", i.e. variables, but this
gets us from 1979011 (just DWARF) to:
$ strip--strip-debug kernel/sched.o
$ ls -la kernel/sched.o
-rw-rw-r-- 1 acme acme 507008 2009-03-30 23:01 kernel/sched.o
25% of the original size.
Of course we don't have inline expansion information, parameter names,
goto labels, etc, but should be good enough for most use cases.
See, without DWARF data, if we ask for it to use DWARF, nothing will be
printed, if we don't speficy the format, it will try first DWARF, it
will not find anything, it will try CTF:
$ pahole -F dwarf kernel/sched.o
$ pahole -C seq_operations kernel/sched.o
struct seq_operations {
void * (*start)(struct seq_file *, loff_t *); /* 0 8 */
void (*stop)(struct seq_file *, void *); /* 8 8 */
void * (*next)(struct seq_file *, void *, loff_t *); /* 16 8 */
int (*show)(struct seq_file *, void *); /* 24 8 */
/* size: 32, cachelines: 1, members: 4 */
/* last cacheline: 32 bytes */
};
$ $ pfunct -Vi -f schedule kernel/sched.o
void schedule(void);
{ /* low_pc=0xe01 */
}/* size: 83 */
$
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It should free ->filename and only close the file and call
elf_end if it was opened at ctf__new.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
And ditch the iterate calling a function interface. I'm trying to get rid of
that in the core (cu__for_each+callback+filter, etc) because doit it
explicitely, like in the kernel, where you have a foo__for_each_bar and do the
filtering directly and process the data, if the processing is simple, right in
the body of the loop, instead of having to go back and forth thru functions.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
And also export the namespace destructor.
The tag__delete destructor now also uses these new destructors.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Arnaldo Carvalho de Melo