/*@z30.c:Symbol uses:InsertUses()@********************************************/
/* */
/* THE LOUT DOCUMENT FORMATTING SYSTEM (VERSION 3.21) */
/* COPYRIGHT (C) 1991, 2000 Jeffrey H. Kingston */
/* */
/* Jeffrey H. Kingston (jeff@cs.usyd.edu.au) */
/* Basser Department of Computer Science */
/* The University of Sydney 2006 */
/* AUSTRALIA */
/* */
/* This program is free software; you can redistribute it and/or modify */
/* it under the terms of the GNU General Public License as published by */
/* the Free Software Foundation; either Version 2, or (at your option) */
/* any later version. */
/* */
/* This program is distributed in the hope that it will be useful, */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
/* GNU General Public License for more details. */
/* */
/* You should have received a copy of the GNU General Public License */
/* along with this program; if not, write to the Free Software */
/* Foundation, Inc., 59 Temple Place, Suite 330, Boston MA 02111-1307 USA */
/* */
/* FILE: z30.c */
/* MODULE: Symbol Uses */
/* EXTERNS: InsertUses(), FlattenUses(), SearchUses(), */
/* FirstExternTarget(), NextExternTarget() */
/* */
/*****************************************************************************/
#include "externs.h"
/*****************************************************************************/
/* */
/* InsertUses(x, y) */
/* */
/* Record the fact that symbol x uses symbol y, by linking them. */
/* Increment count of the number of times y is used, if y is a parameter. */
/* */
/*****************************************************************************/
void InsertUses(OBJECT x, OBJECT y)
{ OBJECT tmp;
debug2(DSU, D, "InsertUses( %s, %s )", SymName(x), SymName(y));
if( type(x) == LOCAL && type(y) == LOCAL && !predefined(y) )
{ GetMem(tmp, USES_SIZE, no_fpos); item(tmp) = y;
if( base_uses(x) == nilobj ) next(tmp) = tmp;
else next(tmp) = next(base_uses(x)), next(base_uses(x)) = tmp;
base_uses(x) = tmp;
}
if( is_par(type(y)) )
{
uses_count(y) += (enclosing(y) == x ? 1 : 2);
if( dirty(y) || uses_count(y) > 1 ) dirty(enclosing(y)) = TRUE;
}
else if( sym_body(y) == nilobj || dirty(y) ) dirty(x) = TRUE;
debug5(DSU, D, "InsertUses returning ( %s %s; %s %s, count = %d )",
SymName(x), (dirty(x) ? "dirty" : "clean"),
SymName(y), (dirty(y) ? "dirty" : "clean"), uses_count(y));
} /* end InsertUses */
/*@::GatherUses(), GatherAllUses(), FlattenUses()@****************************/
/* */
/* static GatherUses(x, sym) */
/* static GatherAllUses(x) */
/* */
/* GatherUses adds all the unmarked descendants of x to the uses relation */
/* of sym; GatherAllUses applies gather_uses to all descendants of x. */
/* */
/*****************************************************************************/
static void GatherUses(OBJECT x, OBJECT sym)
{ OBJECT link, y, tmp;
if( base_uses(x) != nilobj )
{ link = next(base_uses(x));
do
{ y = item(link);
if( marker(y) != sym )
{ if( y != sym )
{ marker(y) = sym;
GetMem(tmp, USES_SIZE, no_fpos); item(tmp) = y;
if( uses(sym) == nilobj ) next(tmp) = tmp;
else next(tmp) = next(uses(sym)), next(uses(sym)) = tmp;
uses(sym) = tmp;
if( indefinite(y) ) indefinite(sym) = TRUE;
if( uses_extern_target(y) ) uses_extern_target(sym) = TRUE;
GatherUses(y, sym);
}
else recursive(sym) = TRUE;
}
link = next(link);
} while( link != next(base_uses(x)) );
}
} /* end GatherUses */
static void GatherAllUses(OBJECT x)
{ OBJECT link, y;
for( link = Down(x); link != x; link = NextDown(link) )
{ Child(y, link);
if( type(y) == LOCAL ) GatherUses(y, y);
GatherAllUses(y);
}
} /* end GatherAllUses */
/*****************************************************************************/
/* */
/* FlattenUses() */
/* */
/* Traverse the directed graph assembled by InsertUses, finding its */
/* transitive closure and storing this explicitly in uses(x) for all x. */
/* */
/*****************************************************************************/
void FlattenUses(void)
{ GatherAllUses(StartSym);
} /* end FlattenUses */
/*@::SearchUses(), FirstExternTarget(), NextExternTarget()@*******************/
/* */
/* BOOLEAN SearchUses(x, y) */
/* */
/* Discover whether symbol x uses symbol y by searching the uses list of x. */
/* */
/*****************************************************************************/
BOOLEAN SearchUses(OBJECT x, OBJECT y)
{ OBJECT p;
debug3(DSU, DD, "SearchUses(%s, %s) uses: %d", SymName(x),SymName(y),uses(x));
if( x == y ) return TRUE;
if( uses(x) != nilobj )
{ p = next(uses(x));
do
{ debug1(DSU, DDD, " checking %s", SymName(item(p)));
if( item(p) == y ) return TRUE;
p = next(p);
} while( p != next(uses(x)) );
}
return FALSE;
} /* end SearchUses */
/*****************************************************************************/
/* */
/* OBJECT FirstExternTarget(sym, cont) */
/* OBJECT NextExternTarget(sym, cont) */
/* */
/* Together these two procedures return all symbols which are both used by */
/* sym and a target for at least one external galley. Return nilobj at end.*/
/* */
/*****************************************************************************/
OBJECT FirstExternTarget(OBJECT sym, OBJECT *cont)
{ OBJECT res;
debug1(DSU, D, "FirstExternTarget( %s )", SymName(sym));
res = nilobj; *cont = nilobj;
if( is_extern_target(sym) ) res = sym;
else if( uses(sym) != nilobj )
{ *cont = next(uses(sym));
do
{ if( is_extern_target(item(*cont)) )
{ res = item(*cont);
break;
}
*cont = next(*cont);
} while( *cont != next(uses(sym)) );
}
debug1(DSU, D, "FirstExternTarget returning %s", SymName(res));
return res;
} /* end FirstExternTarget */
OBJECT NextExternTarget(OBJECT sym, OBJECT *cont)
{ OBJECT res;
debug1(DSU, D, "NextExternTarget( %s )", SymName(sym));
res = nilobj;
if( *cont != nilobj )
{ *cont = next(*cont);
while( *cont != next(uses(sym)) )
{ if( is_extern_target(item(*cont)) )
{ res = item(*cont);
break;
}
*cont = next(*cont);
}
}
debug1(DSU, D, "NextExternTarget returning %s", SymName(res));
return res;
} /* end NextExternTarget */
