Annotation of gforth/backtrace.fs, revision 1.1

1.1     ! anton       1: \ backtrace handling
        !             2: 
        !             3: \ Copyright (C) 1999 Free Software Foundation, Inc.
        !             4: 
        !             5: \ This file is part of Gforth.
        !             6: 
        !             7: \ Gforth is free software; you can redistribute it and/or
        !             8: \ modify it under the terms of the GNU General Public License
        !             9: \ as published by the Free Software Foundation; either version 2
        !            10: \ of the License, or (at your option) any later version.
        !            11: 
        !            12: \ This program is distributed in the hope that it will be useful,
        !            13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
        !            14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        !            15: \ GNU General Public License for more details.
        !            16: 
        !            17: \ You should have received a copy of the GNU General Public License
        !            18: \ along with this program; if not, write to the Free Software
        !            19: \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
        !            20: 
        !            21: 
        !            22: \ growing buffers that need not be full
        !            23: 
        !            24: struct
        !            25:     cell% 0 * field buffer-descriptor \ addr u
        !            26:     cell% field buffer-length
        !            27:     cell% field buffer-address
        !            28:     cell% field buffer-maxlength \ >=length
        !            29: end-struct buffer%
        !            30: 
        !            31: : init-buffer ( addr -- )
        !            32:     buffer% %size erase ;
        !            33: 
        !            34: : adjust-buffer ( u addr -- )
        !            35:     \G adjust buffer% at addr to length u
        !            36:     \ this may grow the allocated area, but never shrinks it
        !            37:     dup >r buffer-maxlength @ over <
        !            38:     if ( u )
        !            39:        r@ buffer-address @ over resize throw r@ buffer-address !
        !            40:        dup r@ buffer-maxlength !
        !            41:     then
        !            42:     r> buffer-length ! ;
        !            43: 
        !            44: \ backtrace stuff
        !            45: 
        !            46: create backtrace-rs-buffer buffer% %allot \ copy of the rturn stack at throw
        !            47: 
        !            48: : init-backtrace ( -- )
        !            49:     backtrace-rs-buffer init-buffer ;
        !            50:     
        !            51: init-backtrace
        !            52: 
        !            53: :noname ( -- )
        !            54:     DEFERS 'cold
        !            55:     init-backtrace ;
        !            56: IS 'cold
        !            57: 
        !            58: : backtrace-return-stack ( -- addr u )
        !            59:     \ addr is the address of top element of return stack (the stack
        !            60:     \ grows downwards), u is the number of aus that interest us on the
        !            61:     \ stack.
        !            62:     rp@ in-return-stack?
        !            63:     if
        !            64:        rp@ [ 2 cells ]L +
        !            65:     else \ throw by signal handler with insufficient information
        !            66:        handler @ cell - \ beyond that we know nothing
        !            67:     then
        !            68:     rp0 @ over - [ 10 cells ]L - 0 max ; \ the bottom 10 cells (and often
        !            69:                                         \ more) are uninteresting
        !            70: 
        !            71: :noname ( -- )
        !            72:     backtrace-empty @
        !            73:     if
        !            74:        backtrace-return-stack
        !            75:        dup backtrace-rs-buffer adjust-buffer
        !            76:        backtrace-rs-buffer buffer-address @ swap move
        !            77:        backtrace-empty off
        !            78:     then ;
        !            79: IS store-backtrace
        !            80: 
        !            81: : print-backtrace ( addr1 addr2 -- )
        !            82:     \G print a backtrace for the return stack addr1..addr2
        !            83:     swap u+do
        !            84:        cr
        !            85:        i @ dup hex. ( return-addr? )
        !            86:        cell - dup in-dictionary? if
        !            87:            @ look drop .name
        !            88:        else
        !            89:            drop
        !            90:        then
        !            91:        cell +loop ;
        !            92: 
        !            93: :noname ( -- )
        !            94:     backtrace-rs-buffer 2@ over + print-backtrace ;
        !            95: IS dobacktrace

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