Next: Auto-map, Previous: Loading Maps, Up: Maps and Map-files [Contents][Index]
It is perfectly possible (and useful!) to load more than one map in the same IO space. It is very natural for a single file, for example, to contain data that can be interpreted in several ways, or of different nature.
Let’s for example open again an ELF file, this time compiled with
-g
:
(poke) .file foo.o
We now load our self
map, to get a view of the file as a collection
of sections:
(poke) .map load self [self](poke)
And now we load the dwarf
map that comes with poke, to get a
view of the file as having debugging information encoded in DWARF:
[self(poke) .map load dwarf [dwarf,self](poke)
See how the prompt now reflects the fact that the current IO space contains DWARF info! Let’s take a look:
[dwarf,self](poke) .info maps IOS Name Source #0 dwarf /home/jemarch/gnu/hacks/poke/maps/dwarf.map #0 self ./self.map [dwarf,self](poke) .map show dwarf Offset Entry 0x5bUL#B $dwarf::info
Now we can access entries from any of the loaded maps, i.e. access the file in terms of different perspectives. As an ELF file:
[dwarf,self](poke) $self::shdr[1] Elf64_Shdr { sh_name=0xb5U#B, sh_type=0x11U, sh_flags=#<>, sh_addr=0x0UL#B, sh_offset=0x40UL#B, sh_size=0x8UL#B, sh_link=0x18U, sh_info=0xfU, sh_addralign=0x4UL, sh_entsize=0x4UL#b }
And as a file containing DWARF info:
[dwarf,self](poke) $dwarf::info Dwarf_CU_Header { unit_length=#<0x0000004eU#B>, version=0x4UH, debug_abbrev_offset=#<0x00000000U#B>, address_size=0x8UB#B }
If you are curious about how the DWARF entries are defined, look at
maps/dwarf.map
in the poke source distribution, or in your
installed poke (.info maps
will tell you the file the map got
loaded from.)
It is possible to unload or remove a map from a given IO space using
the .map remove
dot-command. Say we are done looking at the
DWARF in foo.o, and we are no longer interested in it as a file
containing debugging info. We can do:
[dwarf,self](poke) .map remove dwarf [self](poke)
Note how the prompt was updated accordingly: only self
remains
as a loaded map on this file.
Next: Auto-map, Previous: Loading Maps, Up: Maps and Map-files [Contents][Index]