dbgflags.py now uses +flags to indicate flag namespaces, but our gdb
script only forwarded -f/--flags, which made dbgflags a bit of a pain
to use in the debugger!
Fortunately an easy fix.
Now this works:
(gdb) dbgflags +t trv.gc.t.h.flags
LFS3_T_RDWR 0x00000000 Open traversal as read and write
LFS3_T_MKCONSISTENT 0x00000100 Make the filesystem consistent
LFS3_T_LOOKAHEAD 0x00000200 Repopulate lookahead buffer
LFS3_t_TRAVERSAL 0x60000000 Type = traversal
LFS3_t_MDIR 0x00010000 Btype = mdir
I'm trying to avoid the inevitable conflict with -w/--word, which will
probably become important when exploring non-32-bit filesystem
configurations.
Renaming this to -t/--wait still conflicts with -t/--tree and -t/--tiny,
but as a debug-only flag, I think these are less important.
Oh, and -t/--trace, but test.py/bench.py are already quite different in
their flag naming (see -d/--disk vs -d/--diff).
---
Renamed a few other flags while tweaking things:
- -t/--tiny -> --tiny (dropped shortform)
- -w/--word-bits -> -w/--word/--word-bits
- -t/--tree -> -R/--tree/--rbyd/--tree-rbyd
- -R/--tree-rbyd -> -Y/--rbyd-all/--tree-rbyd-all
- -B/--tree-btree -> -B/--btree/--tree-btree
After tinkering with it a bit, I think the -R/-Y/-B set of flags are a
decent way to organize the tree renderers. At least --tree-rbyd-all does
a better job of describing the difference between --tree-rbyd and
--tree-rbyd-all.
This goes ahead and makes all dbg scripts available in dbg.gdb.py, via
the magic of globbing __file__ relative, and dynamic python class
generation.
Probably one of the more evil scripts I've written, but this means we
don't need to worry about dbg.gdb.py falling out-of-date when adding new
dbg scripts.
Not all of the dbg scripts are useful inside gdb, but most of them are.
After all, what's cooler than this!
(gdb) dbgrbyd -b4096 "disk" -t \
file->b.shrub.blocks[0] \
--trunk lfs3_rbyd_trunk(&file->b.shrub)
rbyd 0x46.23a w2048, rev 00000000, size 629, cksum 8f5169e1
00000004: .-> 0-334 data w335 0
00000009: .-+-> 335 data w1 1 71
0000000e: | .-> 336 data w1 1 67
00000013: .-+-+-> 337 data w1 1 66
...
00000144: | | | | .-> 350 data w1 1 74
0000019a: | | | | .-+-> 351 data w1 1 78
000001f5: | | | | | .-> 352-739 data w388 1 76
00000258: +-+-+-+-+-+-> 740-2047 data w1308 1 6c
Note some tricks to help interact with bash and gdb:
- Flags are passed as is (-b4096, -t, --trunk)
- All non-flags are parsed as expressions (file->b.shrub.blocks[0])
- String expressions may be useful for paths and stuff ("./disk")
So instead of:
$ ./scripts/dbgflags.py o 0x10000003
The filter is now specified as a normal(ish) argparse flag:
$ ./scripts/dbgflags.py --o 0x10000003
This is a bit easier to interop with in dbg.gdb.py, and I think a bit
more readable.
Though -a and --a now do _very_ different things. I'm sure that won't
confuse anyone...
These just invoke the existing dbg*.py python scripts, but allow quick
references to variables in the debugginged process:
(gdb) dbgflags o file->b.o.flags
LFS3_O_RDWR 0x00000002 Open a file as read and write
LFS3_o_REG 0x10000000 Type = regular-file
LFS3_o_UNSYNC 0x01000000 File's metadata does not match disk
Quite neat and useful!
This works by injecting dbg.gdb.py via gdb -x, which includes the
necessary python hooks to add these commands to gdb. This can be
overridden/extended with test.py/bench.py's --gdb-script flag.
Currently limited to scripts that seem the most useful for process
internals:
- dbgerr - Decode littlefs error codes
- dbgflags - Decode littlefs flags
- dbgtag - Decode littlefs tags
Christopher Haster