/* stgout
*
* Writes the staging buffer to the output file via stgstring() (for
* reversing expressions in the buffer) and stgopt() (for optimizing). It
* resets "stgidx".
*
* Global references: stgidx (altered)
* stgbuf (referred to only)
* staging (referred to only)
*/
SC_FUNC void stgout(int index)
{
if (!staging)
return;
stgstring(&stgbuf[index],&stgbuf[stgidx]);
stgidx=index;
}
/* stgout
*
* Writes the staging buffer to the output file via stgstring() (for
* reversing expressions in the buffer) and stgopt() (for optimizing). It
* resets "stgidx".
*
* Global references: stgidx (altered)
* stgbuf (referred to only)
* staging (referred to only)
*/
SC_FUNC void stgout(int index)
{
int reordered=0;
int idx;
if (!staging)
return;
assert(pipeidx==0);
/* first pass: sub-expressions */
if (sc_status==statWRITE)
reordered=stgstring(&stgbuf[index],&stgbuf[stgidx]);
stgidx=index;
/* second pass: optimize the buffer created in the first pass */
if (sc_status==statWRITE) {
if (reordered) {
stgopt(stgpipe,stgpipe+pipeidx,filewrite);
} else {
/* there is no sense in re-optimizing if the order of the sub-expressions
* did not change; so output directly
*/
for (idx=0; idx<pipeidx; idx+=strlen(stgpipe+idx)+1)
filewrite(stgpipe+idx);
} /* if */
} /* if */
pipeidx=0; /* reset second pipe */
}
/* stgstring
*
* Analyses whether code strings should be output to the file as they appear
* in the staging buffer or whether portions of it should be re-ordered.
* Re-ordering takes place in function argument lists; Pawn passes arguments
* to functions from right to left. When arguments are "named" rather than
* positional, the order in the source stream is indeterminate.
* This function calls itself recursively in case it needs to re-order code
* strings, and it uses a private stack (or list) to mark the start and the
* end of expressions in their correct (reversed) order.
* In any case, stgstring() sends a block as large as possible to the
* optimizer stgopt().
*
* In "reorder" mode, each set of code strings must start with the token
* sEXPRSTART, even the first. If the token sSTARTREORDER is represented
* by '[', sENDREORDER by ']' and sEXPRSTART by '|' the following applies:
* '[]...' valid, but useless; no output
* '[|...] valid, but useless; only one string
* '[|...|...] valid and usefull
* '[...|...] invalid, first string doesn't start with '|'
* '[|...|] invalid
*/
static void stgstring(char *start,char *end)
{
char *ptr;
int nest,argc,arg;
argstack *stack;
while (start<end) {
if (*start==sSTARTREORDER) {
start+=1; /* skip token */
/* allocate a argstack with sMAXARGS items */
stack=(argstack *)malloc(sMAXARGS*sizeof(argstack));
if (stack==NULL)
error(103); /* insufficient memory */
nest=1; /* nesting counter */
argc=0; /* argument counter */
arg=-1; /* argument index; no valid argument yet */
do {
switch (*start) {
case sSTARTREORDER:
nest++;
start++;
break;
case sENDREORDER:
nest--;
start++;
break;
default:
if ((*start & sEXPRSTART)==sEXPRSTART) {
if (nest==1) {
if (arg>=0)
stack[arg].end=start-1; /* finish previous argument */
arg=(unsigned char)*start - sEXPRSTART;
stack[arg].start=start+1;
if (arg>=argc)
argc=arg+1;
} /* if */
start++;
} else {
start+=strlen(start)+1;
} /* if */
} /* switch */
} while (nest); /* enddo */
if (arg>=0)
stack[arg].end=start-1; /* finish previous argument */
while (argc>0) {
argc--;
stgstring(stack[argc].start,stack[argc].end);
} /* while */
free(stack);
} else {
ptr=start;
while (ptr<end && *ptr!=sSTARTREORDER)
ptr+=strlen(ptr)+1;
stgopt(start,ptr);
start=ptr;
} /* if */
} /* while */
}