For correctly created and completely parsed debugging information the type will
always be found, but as we still need to parse more tags and expecting
debugging information to be always correctly built is not sane... sprinkle some
asserts.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If passed as the old file, all functions in the new file will appear as being
new, etc.
Suggested by Ilpo Järvinen.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Speeding up the process, no need to check for changes in the same object file,
be it standalone or part of a multi-cu file.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Forgotten change similar to the previous patch.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When we are looking for members of some type in all CUs it may be that in
some CU we don't have the full type, but just a declaration.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
C++ uses this, and to cache the result of the lookup at type__name time we need
to pass the cu to class__name and type__name. Big fallout because of that :-\
But now the output is mucho embelished by the humongous strings representing
C++ templates.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Will be useful to show that the intent is to traverse just the DW_TAG_member
entries in the type list. Right now there are both DW_TAG_inheritance and
DW_TAG_member entries in the ->members type list. But there will be many more
tags, like enumerations, classes, etc, that are defined inside classes, a C++
feature. This will also help with DW_TAG_namespace support.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
This argv munging seems gross, but nah, there are persons wanting to use codiff
on RELA architectures such as x86_64 so lets go with this for now.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
[acme@mica pahole]$ pahole lala
pahole: Permission denied
[acme@mica pahole]$ pahole foo
pahole: No such file or directory
[acme@mica pahole]$ pahole ctracer.c
pahole: couldn't load DWARF info from ctracer.c
[acme@mica pahole]$
Thanks to Matthew Wilcox for noticing how lame it was :-)
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Using export CFLAGS="-Wall -Wfatal-errors -Wformat=2 -Wsequence-point -Wextra
-Wno-parentheses -g", suggested by Davi Arnault, amazing how cruft piles up
when one is not looking ;)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We were comparing DW_TAG_subprogram tags without low_pc/high_pc with
aliases to it, that have low_pc/high_pc, not good.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
We have to check for a possible alias (abstract origin attribute) and handle
that when we want the function name, if it is an alias, do the lookup and cache
the result in ->name, that after all doesn't have a value in the first place.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
As they already look just for DW_TAG_structure_type. Also make it return a
struct tag to avoid having to cast it back and forth too much.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Out of struct typedef_tag, that now becomes the superclass of struct class, and
that also will be for struct enumeration, struct union_type and then finally
for struct struct_type, when struct class finally dies.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
By having its own class, struct typedef_tag.
As it, as structs, unions and enums have a common part, the node and visited
fields, required when emitting its definitions there is an opportunity for
consolidation, that will be explored when adding the specific classes for
DW_TAG_enumeration & DW_TAG_union.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Almost mirroring the DWARF on-disk linkage on memory, more to come before
getting over these simplification refactorings.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Will be reused when handling DW_TAG_subprogram_type more comprehensively, in
the upcoming csets.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
So far struct class was being used as the main data structure, switch to struct
tag, that already was the top of the tag hierarchy, being a struct class
ancestor, so reflect that and stop using struct class as the catch all class,
as a started DW_TAG_array_type tags are now represented by a new class, struct
array_type, reducing the size of struct class and reducing DW__TAG_array_type
instance memory usage.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
So that we can extract bits from one and combine it bits from other instances,
like we'll do in ctracer, where we want to have a cus instance just to get the
kprobes definitions and forward declarations but not handle the methods in it.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
So that we can load many object files, that is what the next csets will
do, to recursively look for files with debug info in a build tree, such
as the kernel one.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
To simplify the callsites and make implementing the same thing on the other
dwarves (prefcnt, pfunct, etc) easy.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
And helper routines, so as to separate DW_TAG_subprogram from
the type tags (DW_TAG_structure_type, basic_type, etc).
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
This should have been done from the start: all DW_TAG_s will be represented by
structs that has as its first member a struct tag, so that we can fully
represent the DWARF information, following csets will take continue the
restructuring.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
This fixes a problem with codiff usage of the ->class_to_diff member, as we
were looking at a different CU than the one intended, so we'd have to have a
pointer to the CU associated with ->class_to_diff, heck, its time to have this
backpointer :-)
Now to audit the rest of the code to look for simplifications since we now have
this backpointer and thus don't need to pass CU pointers around.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Well, needs to be a bit more terse, as prints the types per CU, i.e. for
types defined in multiple CUs we get them repeated, but using grep +
sort -u does the trick.
[acme@newtoy pahole]$ codiff -t /tmp/ipv6.ko.before /tmp/ipv6.ko.after | grep ^struct | sort -u
struct inet_connection_sock: size, offset
struct inet_sock: size, nr_members, offset
struct proto: nr_members, type
struct raw6_sock: size, offset
struct tcp6_sock: size
struct tcp_sock: size, offset
struct udp_sock: size, offset
[acme@newtoy pahole]$
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
[acme@newtoy examples]$ cat struct.c
static struct foo {
char a:2;
unsigned int b;
unsigned long c;
unsigned long d;
unsigned long e;
} bar;
int main(int argc, char *argv[])
{
printf("%d", bar.a);
}
[acme@newtoy examples]$
Then change "a:2" to "a:4":
[acme@newtoy examples]$ codiff -V old_struct new_struct
struct.c:
struct foo | +0
a:2;
from: char /* 0(6) 1(2) */
to: char /* 0(4) 1(4) */
1 struct changed
Now, on top of that move a after b:
[acme@newtoy examples]$ codiff -V old_struct new_struct
struct.c:
struct foo | +0
a:2;
from: char /* 0(6) 1(2) */
to: char /* 4(4) 1(4) */
b;
from: unsigned int /* 4(0) 4(0) */
to: unsigned int /* 0(0) 4(0) */
1 struct changed
[acme@newtoy examples]$
Move it back a to before b and change the type of e without changing its size,
i.e. from unsigned long to long:
[acme@newtoy examples]$ codiff -V old_struct new_struct
struct.c:
struct foo | +0
a:2;
from: char /* 0(6) 1(2) */
to: char /* 0(4) 1(4) */
e;
from: long unsigned int /* 16(0) 4(0) */
to: long int /* 16(0) 4(0) */
1 struct changed
[acme@newtoy examples]$
Now on top of this lets delete the c member:
[acme@newtoy examples]$ codiff -V old_struct new_struct
struct.c:
struct foo | -4
nr_members: -1
-long unsigned int c; /* 8 4 */
a:2;
from: char /* 0(6) 1(2) */
to: char /* 0(4) 1(4) */
d;
from: long unsigned int /* 12(0) 4(0) */
to: long unsigned int /* 8(0) 4(0) */
e;
from: long unsigned int /* 16(0) 4(0) */
to: long int /* 12(0) 4(0) */
1 struct changed
[acme@newtoy examples]$
WOW, many changes, what an ABI breakage, no? :-)
It started as:
[acme@newtoy examples]$ pahole old_struct foo
/* /home/acme/pahole/examples/struct.c:3 */
struct foo {
char a:2; /* 0 1 */
/* XXX 3 bytes hole, try to pack */
unsigned int b; /* 4 4 */
long unsigned int c; /* 8 4 */
long unsigned int d; /* 12 4 */
long unsigned int e; /* 16 4 */
}; /* size: 20, sum members: 17, holes: 1, sum holes: 3 */
And ended up as:
[acme@newtoy examples]$ pahole new_struct foo
/* /home/acme/pahole/examples/struct.c:3 */
struct foo {
char a:4; /* 0 1 */
/* XXX 3 bytes hole, try to pack */
unsigned int b; /* 4 4 */
long unsigned int d; /* 8 4 */
long int e; /* 12 4 */
}; /* size: 16, sum members: 13, holes: 1, sum holes: 3 */
[acme@newtoy examples]$
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
First step:
Show if struct members were removed or added:
[acme@newtoy net-2.6.20]$ codiff -sV /tmp/ipv6.ko.before /tmp/ipv6.ko.after
<SNIP>
/pub/scm/linux/kernel/git/acme/net-2.6.20/net/ipv6/tcp_ipv6.c:
struct inet_sock | -4
nr_members: -1
struct inet_connection_sock | -4
struct tcp_sock | -4
struct tcp6_sock | -4
4 structs changed
<SNIP>
Oh, so struct inet_sock must be one of the members of the other structs that
haven't had changes in its number of members? Yes, this is the case :-)
Now lets see _which_ members were removed, added or had its type changed
causing a reduction in the struct size.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Arnaldo Carvalho de Melo
Ilpo Järvinen
Arnaldo Carvalho de Melo
Arnaldo Carvalho de Melo