| @(#) $Id$ |
| |
| This is still somewhat skank, but sure beats doing it by hand. |
| |
| The idea is to use gcc (which must have been compiled |
| "--with-stabs" which is not the default when configured |
| native on SCO) to parse a header file and emit GNU/BSD .stabs |
| records to get the size/addresses of structures. |
| |
| I've modified a version of pstruct (from the Perl 4.036 |
| distribution, requires Perl) to deal with the recent |
| changes in GCC that allow multiline/quasi-recursive .stabs |
| definitions. (I've sent this to lwall@netlabs.com and |
| tchrist, but it's unknown if this will make it to the Perl 5 |
| distribution.) |
| |
| Make a tiny little compilable file that includes the headers |
| you want. BE CERTAIN TO GET YOUR MANIFEST CONSTANTS RIGHT. |
| If this file compiles with different #defines from your Driver.o, |
| interesting things may happen to your structure sizes. |
| |
| In my example, demo_mkd.c is this file: |
| |
| #include <sys/types.h> |
| |
| #define _INKERNEL |
| #include <sys/tty.h> |
| |
| main(){} |
| |
| Now, invoke "pstruct -w" on this file. mk_kme_defs (requires |
| Perl) parses this output. Here's a simple command line: |
| |
| ./pstruct -w demo_mkd.c | mk_kme_defs > kme_defs |
| |
| |
| BUGS |
| Unions confuse mk_kme_defs very badly. I |
| prefer to take the output of pstruct (which does |
| appear to do the right thing for unions), hand edit |
| out the union stuff, and feed this "fixed" file |
| to mk_kme_defs. |
| |
| Machine generated kme_defs files contain room for |
| aesthetic optimizations, but are very accurate |
| with regards to padding, alignment, and structure |
| size. |
| |
| Specifically, long member names tend to shuffle |
| the screens in bad ways. mk_kme_defs should also |
| be aware of "invariant constants" in member names. |
| Take this example from tty.h... |
| |
| !tty "c_cc" "c_cf" n |
| lln |
| "c_cl" "c_cc" "c_cf" "c_cl" "c_cc" n |
| llllln |
| "c_cf" "c_cl" "c_ptr" "c_count" "c_size" "c_ptr" n |
| lllxxln |
| "c_count" "c_size" "t_proc" "t_iflag" "t_oflag" "t_cflag" "t_lflag" "t_state" n |
| xxlxxxxxn |
| "t_pgrp" "t_line" "t_delct" "t_term" "t_tmflag" "t_col" "t_row" "t_vrow" "t_lrow" n |
| xbbbbbbbbn |
| "t_hqcnt" "t_dstat" "t_cc[13]" "t_mstate" "t_merr" n |
| bb13bbbn |
| "t_xstate" "ciflag" "ciowner" "t_xmp" "t_schar" "t_yyy[3]" n |
| bbblb3bn |
| |
| Mk_kme_defs should probably recognize the leading "?_" |
| regex and delete them. This would make "t_iflag" into |
| "iflag". |
| |
| It could also optimize lines like: |
| |
| xbbbbbbbbn |
| |
| to use the repeat prefix operator like |
| |
| x8bn |
| |
| I have not done this at this point, becuase of the very |
| real chance that you will have to manually move things from |
| one line to the next. |
| |
| TODO |
| |
| This certainly seems a scenic route to extract alignment, |
| structure size, and padding out of a program. It is rumoured |
| that extracting it from ELF binaries may be easier, but this |
| mess is known to work on most UNIX-like substances. Sigh. |
| |
| --- |
| Robert Lipe Sr. Software Engr. Arnet Corp. robertl@arnet.com |