#: 15753 S12/OS9/68000 (OSK)
    02-Jul-92  23:58:24
Sb: #15752-C_Question
Fm: Kevin Darling 76703,4227
To: Kevin Darling 76703,4227 (X)

So now we look at Pete's example (very slightly modified):

main() {    int x;
     char a[5][200];
     for (x = 0; x <= 5; ++x)
          gets(a[x]); }

 psect test_c,0,0,0,0,0 * main() * {
 ttl main main:
 pshs u
 ldd #_1
 lbsr _stkcheck

* int x; * char a[5][200]; * * for (x = 0; x <= 5; ++x)
 leas -1002,s  # make room for int_x and 5*200 one-byte chars
 clra
 clrb
 std 1000,s    # x=0
 lbra _4       # enter "for" loop

* gets(a[x]); _2
 ldd 1000,s    # x
 pshs d
 ldd #200      # size of each array element
 lbsr  ccmult  # multiply stack param (x) * array_element_size
 leax 0,s      # point to beginning of array
 leax d,x      # point to a[x][0]
 pshs x        # push parameter for gets
 lbsr gets     # call gets function
 leas 2,s * } _5
 ldd 1000,s    # x=x+1
 addd #1
 std 1000,s _4
 ldd 1000,s    # etc
 cmpd #5
 lble _2 _3
 leas 1002,s
 puls u,pc _1 equ -1072
 endsect

Now, even tho we had to guess at the function of ccmult, it was still clear
that we were passing the address of an _allocated_ char subarray to the gets
function... and not just a pointer to hyperspace.  Does this make sense?

The other thing that looking at -ca output does is to impress the fact that C
is basically an assembly macro language... and that *pointers are just
variables being used as extra "index registers".  best - kevin