4.3BSD - /usr/src/new/icon/lib/pfail.s

   1: #include "../h/config.h"
   2: /*
   3:  * pfail - returns from an Icon procedure with failure.
   4:  *  The current procedure frame is exited and efail causes
   5:  *  the failure of the enclosing expression.  A tracing
   6:  *  message is produced if &trace is non-zero.
   7:  */
   8: Global(_k_level)
   9: Global(_k_trace)
  10: Global(_efail)
  11: Global(_ftrace)
  12: Global(_pfail)
  13: Global(_line)
  14: Global(_file)
  15: 
  16: #ifdef VAX
  17: _pfail:
  18:         decl    _k_level        # A procedure is being exited, so
  19:                                 #  decrement &level.
  20:         tstl    _k_trace        # If &trace is zero,
  21:         beql    dofail          #  no tracing.
  22:                                 #
  23:                                 # Otherwise, a trace message is
  24:                                 #  produced by calling ftrace with
  25:                                 #  the address of the block of the
  26:                                 #  failing procedure.
  27:                                 # &arg0 = (nargs * 8) + 8 + ap
  28:         ashl    $3,4(ap),r0     # r0 = nargs * 8
  29:         addl2   $8,r0           #  + 8
  30:         addl3   r0,ap,r0        #  + ap
  31:                                 # r0 points to descriptor for procedure
  32:         pushl   4(r0)           #  and second word is address of block
  33:         calls   $1,_ftrace      # ftrace(&arg0)
  34: 
  35: dofail:
  36:         movl    -4(fp),_line    # Restore _line,
  37:         movl    -8(fp),_file    #  _file,
  38:         movl    -4(ap),efp      #  expression frame pointer,
  39:         movl    -8(ap),gfp      #  generator frame pointer,
  40:         movl    -12(ap),ipc     #  interpreter pc,
  41:         movl    8(fp),ap        #  ap,
  42:         movl    12(fp),fp       #  and fp from failing procedure frame
  43:         jmp     _efail          # Cause failure in expression by
  44:                                 #  branching to efail
  45: #endif VAX
  46: 
  47: #ifdef PORT
  48: DummyFcn(_pfail)
  49: #endif PORT
  50: #ifdef PDP11
  51: / pfail - return from an Icon procedure with failure.
  52: / Exit the current procedure frame, and branch to _efail.
  53: Global(_boundary)
  54: 
  55: _pfail:
  56:         dec     _k_level        / decrement &level
  57: 
  58: / Print trace message if &trace is set.
  59: 
  60:         tst     _k_trace
  61:         beq     1f
  62:         mov     4(r5),r0        / calculate address of arg0
  63:         asl     r0              /   r0 <- r5 + 4*nargs + 6
  64:         asl     r0
  65:         add     r5,r0
  66:         add     $6,r0
  67:         mov     2(r0),-(sp)     / push address of failing procedure block
  68:         mov     $1,_boundary    / prevent csv from setting boundary
  69:         jsr     pc,_ftrace
  70:         clr     _boundary
  71:         tst     (sp)+           / pop address of procedure block
  72: 
  73: / Exit the procedure frame, decrement &level, and jump to efail.
  74: 
  75: 1:
  76:         mov     r5,r0
  77:         mov     -(r0),r4
  78:         mov     -(r0),r3
  79:         mov     -(r0),r2
  80:         mov     -(r0),_line
  81:         mov     -(r0),_file
  82:         mov     r5,sp
  83:         mov     (sp)+,r5
  84:         jmp     _efail          / pass failure to expression frame
  85: #endif PDP11

Defined functions