63 lines
1.4 KiB
C
63 lines
1.4 KiB
C
/* S C O P E M E C H A N I S M */
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static char *RcsId = "$Header$";
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#include <assert.h>
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#include <alloc.h>
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#include "scope.h"
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static int maxscope; /* maximum assigned scope number */
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struct scope *CurrentScope;
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/* STATICALLOCDEF "scope" */
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/* Open a scope that is either open (automatic imports) or closed.
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A closed scope is handled by adding an extra entry to the list
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with scope number 0. This has two purposes: it makes scope 0
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visible, and it marks the end of a visibility list.
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Scope 0 is the pervasive scope, the one that is always visible.
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A disadvantage of this method is that we cannot open scope 0
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explicitly.
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*/
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open_scope(scopetype, scopenr)
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{
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register struct scope *sc = new_scope();
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register struct scope *sc1;
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sc->sc_scope = scopenr == 0 ? ++maxscope : scopenr;
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assert(scopetype == OPENSCOPE || scopetype == CLOSEDSCOPE);
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sc1 = CurrentScope;
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if (scopetype == CLOSEDSCOPE) {
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sc1 = new_scope();
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sc1->sc_scope = 0; /* Pervasive scope nr */
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sc1->next = CurrentScope;
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}
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sc->next = sc1;
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CurrentScope = sc;
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}
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close_scope()
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{
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register struct scope *sc = CurrentScope;
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assert(sc != 0);
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if (sc->next && (sc->next->sc_scope == 0)) {
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struct scope *sc1 = sc;
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sc = sc->next;
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free_scope(sc1);
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}
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CurrentScope = sc->next;
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free_scope(sc);
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}
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init_scope()
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{
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register struct scope *sc = new_scope();
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sc->sc_scope = 0;
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sc->next = 0;
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CurrentScope = sc;
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}
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