| [9] | 1 | #
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| 2 | mes 2,_EM_WSIZE,_EM_PSIZE
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| 3 | ;
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| 4 | ; layout of a setjmp buffer:
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| 5 | ;
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| 6 | ; -----------------
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| 7 | ; | flag | (!0 when blocked signals saved (POSIX))
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| 8 | ; -----------------
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| 9 | ; | signal mask/set | (for Berkeley 4.[2-] / POSIX)
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| 10 | ; -----------------
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| 11 | ; | |
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| 12 | ; | GTO descriptor |
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| 13 | ; | (SP, LB, PC) |
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| 14 | ; | |
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| 15 | ; -----------------
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| 16 | ;
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| 17 | ; setjmp saves the signalmask, PC, SP, and LB of caller, and creates a
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| 18 | ; GTO descriptor from this.
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| 19 | ; The big problem here is how to get the return address, i.e. the PC of
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| 20 | ; the caller; This problem is solved by the front-end, which must pass
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| 21 | ; it as an extra parameter to setjmp.
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| 22 |
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| 23 | ; a GTO descriptor must be in the global data area
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| 24 | gtobuf
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| 25 | bss 3*_EM_PSIZE,0,0
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| 26 |
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| 27 | inp $fill_ret_area
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| 28 | exp $__setjmp
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| 29 | pro $__setjmp,0
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| 30 | #if defined(_POSIX_SOURCE)
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| 31 | ; save mask of currently blocked signals.
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| 32 | ; longjmp must restore this mask
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| 33 | lol _EM_PSIZE ; the flag integer at offset _EM_PSIZE
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| 34 | lal 0
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| 35 | loi _EM_PSIZE
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| 36 | stf 3*_EM_PSIZE+_EM_LSIZE
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| 37 | lol _EM_PSIZE ; the flag integer at offset _EM_PSIZE
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| 38 | zeq *1
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| 39 | lal 0
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| 40 | loi _EM_PSIZE
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| 41 | adp 3*_EM_PSIZE
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| 42 | cal $__newsigset
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| 43 | asp _EM_PSIZE
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| 44 | 1
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| 45 | #elif defined(__BSD4_2)
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| 46 | loc 0
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| 47 | cal $sigblock
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| 48 | asp _EM_WSIZE
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| 49 | lfr _EM_WSIZE
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| 50 | lal 0
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| 51 | loi _EM_PSIZE
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| 52 | stf 3*_EM_PSIZE
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| 53 | #endif
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| 54 | ; create GTO descriptor for longjmp
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| 55 | lxl 0
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| 56 | dch ; Local Base of caller
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| 57 | lxa 0 ; Stackpointer of caller
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| 58 | lal _EM_PSIZE+_EM_WSIZE
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| 59 | loi _EM_PSIZE ; Return address of caller
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| 60 | lal 0
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| 61 | loi _EM_PSIZE ; address of jmpbuf
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| 62 | sti 3*_EM_PSIZE ; LB, SP, and PC stored in jmpbuf
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| 63 | loc 0
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| 64 | ret _EM_WSIZE ; setjmp must return 0
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| 65 | end 0
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| 66 |
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| 67 | pro $fill_ret_area,0
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| 68 | ; put argument in function result area
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| 69 | lol 0
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| 70 | ret _EM_WSIZE
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| 71 | end 0
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| 72 |
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| 73 | exp $longjmp
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| 74 | pro $longjmp,?
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| 75 | #if defined(_POSIX_SOURCE)
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| 76 | ; restore blocked mask
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| 77 | lal 0
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| 78 | loi _EM_PSIZE
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| 79 | lof 3*_EM_PSIZE+_EM_LSIZE
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| 80 | zeq *2
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| 81 | lal 0
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| 82 | loi _EM_PSIZE
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| 83 | adp 3*_EM_PSIZE
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| 84 | cal $__oldsigset
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| 85 | asp _EM_PSIZE
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| 86 | 2
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| 87 | #elif defined(__BSD4_2)
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| 88 | ; restore signal mask
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| 89 | lal 0
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| 90 | loi _EM_PSIZE
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| 91 | lof 3*_EM_PSIZE
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| 92 | cal $_sigsetmask
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| 93 | asp _EM_WSIZE
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| 94 | lfr _EM_WSIZE
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| 95 | asp _EM_WSIZE
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| 96 | #endif
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| 97 | lal 0
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| 98 | loi _EM_PSIZE ; address of jmpbuf
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| 99 | lae gtobuf
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| 100 | blm 3*_EM_PSIZE ; fill GTO descriptor from jmpbuf
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| 101 | lol _EM_PSIZE ; second parameter of longjmp: the return value
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| 102 | dup _EM_WSIZE
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| 103 | zne *3
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| 104 | ; of course, longjmp may not return 0!
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| 105 | inc
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| 106 | 3
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| 107 | ; put return value in function result area
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| 108 | cal $fill_ret_area
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| 109 | asp _EM_WSIZE
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| 110 | gto gtobuf ; there we go ...
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| 111 | ; ASP and GTO do not damage function result area
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| 112 | end 0
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