ack/util/ack/scan.c
1987-03-10 01:26:51 +00:00

255 lines
6.3 KiB
C

/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*
*/
#include "ack.h"
#include "list.h"
#include "trans.h"
#include "data.h"
#ifndef NORCSID
static char rcs_id[] = "$Header$" ;
#endif
enum f_path getpath(first) register trf **first ; {
/* Try to find a transformation path */
start_scan();
/*
The end result is the chaining of
the consequtive phases with the t_next field.
The list is scanned for possible transformations
stopping at stopsuffix or the last transformation in the list.
The scan flags are set by this process.
When a transformation is found, it is compared with
the last transformation found.
*/
try(l_first(tr_list),p_suffix);
return scan_end(first);
}
/******************** data used only while scanning *******************/
static int last_pcount; /* The added priority of
the best path so far */
static int last_ncount; /* The # of non-optimizing transformations
in the best path sofar */
static int last_ocount; /* The # of optimizing transformations in the
best path sofar */
static int suf_found; /* Was the suffix at least recognized ? */
/******************** The hard work ********************/
start_scan() {
register list_elem *scan ;
scanlist(l_first(tr_list),scan) {
t_cont(*scan)->t_scan=NO ;
}
suf_found= 0 ;
#ifdef DEBUG
if ( debug>=3 ) vprint("Scan_start\n");
#endif
last_ncount= -1 ;
last_ocount= 0 ;
}
try(f_scan,suffix) list_elem *f_scan; char *suffix; {
register list_elem *scan ;
register trf *trafo ;
/* Try to find a transformation path starting at f_scan for a
file with the indicated suffix.
If the suffix is already reached or a combiner is found
call scan_found() to OK the scan.
If a transformation is found it calls itself recursively
with as starting point the next transformation in the list.
*/
if ( stopsuffix && *stopsuffix && strcmp(stopsuffix,suffix)==0 ) {
scan_found();
return ;
}
if (! f_scan) return;
scanlist(f_scan, scan) {
trafo= t_cont(*scan) ;
if ( satisfy(trafo,suffix) ) {
/* Found a transformation */
suf_found= 1;
#ifdef DEBUG
if ( debug>=4 ) {
vprint("Found %s for %s: result %s\n",
trafo->t_name,suffix,trafo->t_out);
}
#endif
trafo->t_scan=YES ;
if ( trafo->t_prep ) {
if ( !cpp_trafo ) {
find_cpp() ;
}
if ( stopsuffix &&
strcmp(stopsuffix,
cpp_trafo->t_out)==0 )
{
scan_found() ;
return ;
}
}
if ( trafo->t_next ) {
/* We know what happens from this phase on,
so take a shortcut.
*/
register trf *sneak ;
sneak= trafo ;
while( sneak=sneak->t_next ) {
sneak->t_scan=YES ;
}
scan_found() ;
sneak= trafo ;
while( sneak=sneak->t_next ) {
sneak->t_scan=NO ;
}
return ;
}
if ( trafo->t_linker && stopsuffix && !*stopsuffix ) {
trafo->t_scan=NO ;
scan_found() ;
return ;
}
if (! l_next(*scan) && !stopsuffix) {
scan_found() ;
} else {
try(l_next(*scan),trafo->t_out);
}
trafo->t_scan= NO ;
}
}
}
scan_found() {
register list_elem *scan;
int ncount, ocount, pcount ;
suf_found= 1;
#ifdef DEBUG
if ( debug>=3 ) vprint("Scan found\n") ;
#endif
/* Gather data used in comparison */
ncount=0; ocount=0; pcount=0;
scanlist(l_first(tr_list),scan) {
if (t_cont(*scan)->t_scan) {
#ifdef DEBUG
if ( debug>=4 ) vprint("%s-",t_cont(*scan)->t_name) ;
#endif
if( t_cont(*scan)->t_optim ) ocount++ ;else ncount++ ;
pcount += t_cont(*scan)->t_priority ;
}
}
#ifdef DEBUG
if ( debug>=4 ) vprint("\n");
#endif
/* Is this transformation better then any found yet ? */
#ifdef DEBUG
if ( debug>=3 ) {
vprint("old n:%d, o:%d, p:%d - new n:%d, o:%d, p:%d\n",
last_ncount,last_ocount,last_pcount,
ncount,ocount,pcount) ;
}
#endif
if ( last_ncount== -1 || /* None found yet */
last_pcount<pcount || /* Better priority */
( last_pcount==pcount && /* Same prio, and */
( last_ncount>ncount || /* Shorter nec. path */
(last_ncount==ncount && /* Same nec. path, optimize?*/
(Optflag? last_ocount<ocount : last_ocount>ocount ))))) {
/* Yes it is */
#ifdef DEBUG
if ( debug>=3 ) vprint("Better\n");
#endif
scanlist(l_first(tr_list),scan) {
t_cont(*scan)->t_bscan=t_cont(*scan)->t_scan;
}
last_ncount=ncount; last_ocount=ocount; last_pcount=pcount;
}
}
int satisfy(trafo,suffix) register trf *trafo; char *suffix ; {
register char *f_char, *l_char ;
/* Check whether this transformation is present for
the current machine and the parameter suffix is among
the input suffices. If so, return 1. 0 otherwise
*/
if ( trafo->t_isprep ) return 0 ;
l_char=trafo->t_in ;
while ( l_char ) {
f_char= l_char ;
if ( *f_char!=SUFCHAR || ! *(f_char+1) ) {
fuerror("Illegal input suffix entry for %s",
trafo->t_name) ;
}
l_char=strindex(f_char+1,SUFCHAR);
if ( l_char ) *l_char = 0;
if ( strcmp(f_char,suffix)==0 ) {
if ( l_char ) *l_char = SUFCHAR;
return 1;
}
if ( l_char ) *l_char = SUFCHAR;
}
return 0 ;
}
enum f_path scan_end(first) trf **first ; { /* Finalization */
/* Return value indicating whether a transformation was found */
/* Set the flags for the transformation up to, but not including,
the combiner
*/
register trf *prev, *curr ;
register list_elem *scan;
#ifdef DEBUG
if ( debug>=3 ) vprint("End_scan\n");
#endif
if ( last_ncount== -1 ) return suf_found ? F_NOPATH : F_NOMATCH ;
#ifdef DEBUG
if ( debug>=2 ) vprint("Transformation found\n");
#endif
prev= (trf *)0 ; *first= prev ;
scanlist(l_first(tr_list),scan) {
curr= t_cont(*scan) ;
if ( curr->t_bscan ) {
if ( prev ) {
prev->t_next= curr ;
if ( curr->t_linker ) prev->t_keep=YES ;
} else {
*first= curr ;
}
if ( curr->t_next ) {
return F_OK ;
}
prev=curr ;
}
}
if ( cpp_trafo && stopsuffix &&
strcmp(stopsuffix,cpp_trafo->t_out)==0 ) {
cpp_trafo->t_keep=YES ;
}
if ( prev ) {
prev->t_keep=YES ;
}
return F_OK ;
}
find_cpp() {
register list_elem *elem ;
scanlist( l_first(tr_list), elem ) {
if ( t_cont(*elem)->t_isprep ) {
if ( cpp_trafo ) fuerror("Multiple cpp's present") ;
cpp_trafo= t_cont(*elem) ;
}
}
if ( !cpp_trafo ) fuerror("No cpp present") ;
}