mirror of git://git.psyced.org/git/psyclpc
360 lines
11 KiB
C
360 lines
11 KiB
C
/*
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* Copyright (c) 1985 Sun Microsystems, Inc.
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* Copyright (c) 1980 The Regents of the University of California.
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* Copyright (c) 1976 Board of Trustees of the University of Illinois.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the University of California, Berkeley, the University of Illinois,
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* Urbana, and Sun Microsystems, Inc. The name of either University
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* or Sun Microsystems may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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#ifndef lint
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static char sccsid[] = "@(#)parse.c 5.8 (Berkeley) 9/15/88";
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#endif /* not lint */
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#include "indent_globs.h"
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struct parser_state *parser_state_tos;
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/* like ++parser_state_tos->tos but checks for stack overflow and extends
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stack if necessary. */
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static int
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inc_pstack ()
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{
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if (++parser_state_tos->tos >= parser_state_tos->p_stack_size)
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{
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parser_state_tos->p_stack_size *= 2;
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parser_state_tos->p_stack = (enum codes *)
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xrealloc (parser_state_tos->p_stack,
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parser_state_tos->p_stack_size * sizeof (enum codes));
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parser_state_tos->il = (int *)
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xrealloc (parser_state_tos->il,
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parser_state_tos->p_stack_size * sizeof (int));
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parser_state_tos->cstk = (int *)
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xrealloc (parser_state_tos->cstk,
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parser_state_tos->p_stack_size * sizeof (int));
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}
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return parser_state_tos->tos;
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}
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void
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parse(tk)
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enum codes tk; /* the code for the construct scanned */
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{
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int i;
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#ifdef debug
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printf("%2d - %s\n", tk, token);
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#endif
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while (parser_state_tos->p_stack[parser_state_tos->tos] == ifhead && tk != elselit) {
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/* true if we have an if without an else */
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parser_state_tos->p_stack[parser_state_tos->tos] = stmt; /* apply the if(..) stmt ::= stmt
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* reduction */
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reduce(); /* see if this allows any reduction */
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}
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switch (tk) { /* go on and figure out what to do with the
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* input */
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case decl: /* scanned a declaration word */
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parser_state_tos->search_brace = btype_2;
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/* indicate that following brace should be on same line */
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if (parser_state_tos->p_stack[parser_state_tos->tos] != decl) { /* only put one declaration
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* onto stack */
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break_comma = true; /* while in declaration, newline should be
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* forced after comma */
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parser_state_tos->p_stack[inc_pstack()] = decl;
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parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->i_l_follow;
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if (ljust_decl) {/* only do if we want left justified
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* declarations */
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parser_state_tos->ind_level = 0;
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for (i = parser_state_tos->tos - 1; i > 0; --i)
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if (parser_state_tos->p_stack[i] == decl)
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/* indentation is number of declaration levels deep
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we are times spaces per level */
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parser_state_tos->ind_level += ind_size;
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parser_state_tos->i_l_follow = parser_state_tos->ind_level;
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}
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}
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break;
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case ifstmt: /* scanned if (...) */
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if (parser_state_tos->p_stack[parser_state_tos->tos] == elsehead
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&& else_if) /* "else if ..." */
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parser_state_tos->i_l_follow = parser_state_tos->il[parser_state_tos->tos];
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case dolit: /* 'do' */
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case forstmt: /* for (...) */
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inc_pstack();
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parser_state_tos->p_stack[parser_state_tos->tos] = tk;
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parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->ind_level = parser_state_tos->i_l_follow;
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parser_state_tos->i_l_follow += ind_size; /* subsequent statements should be indented 1 */
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parser_state_tos->search_brace = btype_2;
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break;
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case lbrace: /* scanned { */
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break_comma = false; /* don't break comma in an initial list */
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if (parser_state_tos->p_stack[parser_state_tos->tos] == stmt || parser_state_tos->p_stack[parser_state_tos->tos] == decl
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|| parser_state_tos->p_stack[parser_state_tos->tos] == stmtl)
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/* it is a random, isolated stmt group or a declaration */
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parser_state_tos->i_l_follow += ind_size;
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else {
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if (s_code == e_code) {
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/*
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* only do this if there is nothing on the line
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*/
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parser_state_tos->ind_level -= ind_size;
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/*
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* it is a group as part of a while, for, etc.
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*/
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/* For -bl formatting, indent by brace_indent
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additional spaces
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e.g.
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if (foo == bar)
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{
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<--> brace_indent spaces (in this example, 4)
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*/
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if (!btype_2)
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{
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parser_state_tos->ind_level += brace_indent;
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parser_state_tos->i_l_follow += brace_indent;
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if (parser_state_tos->p_stack[parser_state_tos->tos] == swstmt)
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case_ind += brace_indent;
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}
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if (parser_state_tos->p_stack[parser_state_tos->tos] == swstmt
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&& case_indent
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>= ind_size)
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parser_state_tos->ind_level -= ind_size;
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/*
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* for a switch, brace should be two levels out from the code
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*/
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}
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}
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inc_pstack();
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parser_state_tos->p_stack[parser_state_tos->tos] = lbrace;
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parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->ind_level;
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inc_pstack();
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parser_state_tos->p_stack[parser_state_tos->tos] = stmt;
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/* allow null stmt between braces */
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parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->i_l_follow;
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break;
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case whilestmt: /* scanned while (...) */
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if (parser_state_tos->p_stack[parser_state_tos->tos] == dohead) {
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/* it is matched with do stmt */
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parser_state_tos->ind_level = parser_state_tos->i_l_follow = parser_state_tos->il[parser_state_tos->tos];
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inc_pstack();
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parser_state_tos->p_stack[parser_state_tos->tos] = whilestmt;
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parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->ind_level = parser_state_tos->i_l_follow;
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}
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else { /* it is a while loop */
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inc_pstack();
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parser_state_tos->p_stack[parser_state_tos->tos] = whilestmt;
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parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->i_l_follow;
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parser_state_tos->i_l_follow += ind_size;
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parser_state_tos->search_brace = btype_2;
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}
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break;
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case elselit: /* scanned an else */
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if (parser_state_tos->p_stack[parser_state_tos->tos] != ifhead)
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diag(1, "Unmatched 'else'");
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else {
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parser_state_tos->ind_level = parser_state_tos->il[parser_state_tos->tos]; /* indentation for else should
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* be same as for if */
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/* everything following should be in 1 level */
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parser_state_tos->i_l_follow = parser_state_tos->ind_level + ind_size;
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parser_state_tos->p_stack[parser_state_tos->tos] = elsehead;
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/* remember if with else */
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parser_state_tos->search_brace = btype_2 | else_if;
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}
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break;
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case rbrace: /* scanned a } */
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/* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */
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if (parser_state_tos->p_stack[parser_state_tos->tos - 1] == lbrace) {
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parser_state_tos->ind_level = parser_state_tos->i_l_follow = parser_state_tos->il[--parser_state_tos->tos];
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parser_state_tos->p_stack[parser_state_tos->tos] = stmt;
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}
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else
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diag(1, "Stmt nesting error.");
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break;
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case swstmt: /* had switch (...) */
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inc_pstack();
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parser_state_tos->p_stack[parser_state_tos->tos] = swstmt;
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parser_state_tos->cstk[parser_state_tos->tos] = case_ind;
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/* save current case indent level */
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parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->i_l_follow;
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case_ind = parser_state_tos->i_l_follow + case_indent; /* cases should be one
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* level down from
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* switch */
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/* statements should be two levels in */
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parser_state_tos->i_l_follow += case_indent + ind_size;
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parser_state_tos->search_brace = btype_2;
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break;
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case semicolon: /* this indicates a simple stmt */
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break_comma = false; /* turn off flag to break after commas in a
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* declaration */
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inc_pstack();
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parser_state_tos->p_stack[parser_state_tos->tos] = stmt;
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parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->ind_level;
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break;
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default: /* this is an error */
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diag(1, "Unknown code to parser");
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return;
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} /* end of switch */
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reduce(); /* see if any reduction can be done */
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#ifdef debug
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for (i = 1; i <= parser_state_tos->tos; ++i)
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printf("(%d %d)", parser_state_tos->p_stack[i], parser_state_tos->il[i]);
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printf("\n");
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#endif
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return;
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}
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/*
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* Copyright (C) 1976 by the Board of Trustees of the University of Illinois
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*
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* All rights reserved
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*
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*
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* NAME: reduce
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*
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* FUNCTION: Implements the reduce part of the parsing algorithm
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*
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* ALGORITHM: The following reductions are done. Reductions are repeated until
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* no more are possible.
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*
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* Old TOS New TOS <stmt> <stmt> <stmtl> <stmtl> <stmt> <stmtl> do
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* <stmt> "dostmt" if <stmt> "ifstmt" switch <stmt> <stmt> decl
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* <stmt> <stmt> "ifelse" <stmt> <stmt> for <stmt> <stmt> while
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* <stmt> <stmt> "dostmt" while <stmt>
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*
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* On each reduction, parser_state_tos->i_l_follow (the indentation for the following line) is
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* set to the indentation level associated with the old TOS.
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*
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* PARAMETERS: None
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*
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* RETURNS: Nothing
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*
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* GLOBALS: parser_state_tos->cstk parser_state_tos->i_l_follow = parser_state_tos->il parser_state_tos->p_stack = parser_state_tos->tos =
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*
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* CALLS: None
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*
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* CALLED BY: parse
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*
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* HISTORY: initial coding November 1976 D A Willcox of CAC
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*
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*/
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/*----------------------------------------------*\
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| REDUCTION PHASE |
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\*----------------------------------------------*/
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reduce()
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{
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register int i;
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for (;;) { /* keep looping until there is nothing left to
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* reduce */
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switch (parser_state_tos->p_stack[parser_state_tos->tos]) {
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case stmt:
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switch (parser_state_tos->p_stack[parser_state_tos->tos - 1]) {
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case stmt:
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case stmtl:
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/* stmtl stmt or stmt stmt */
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parser_state_tos->p_stack[--parser_state_tos->tos] = stmtl;
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break;
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case dolit: /* <do> <stmt> */
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parser_state_tos->p_stack[--parser_state_tos->tos] = dohead;
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parser_state_tos->i_l_follow = parser_state_tos->il[parser_state_tos->tos];
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break;
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case ifstmt:
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/* <if> <stmt> */
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parser_state_tos->p_stack[--parser_state_tos->tos] = ifhead;
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for (i = parser_state_tos->tos - 1;
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(
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parser_state_tos->p_stack[i] != stmt
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&&
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parser_state_tos->p_stack[i] != stmtl
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&&
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parser_state_tos->p_stack[i] != lbrace
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);
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--i);
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parser_state_tos->i_l_follow = parser_state_tos->il[i];
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/*
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* for the time being, we will assume that there is no else on
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* this if, and set the indentation level accordingly. If an
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* else is scanned, it will be fixed up later
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*/
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break;
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case swstmt:
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/* <switch> <stmt> */
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case_ind = parser_state_tos->cstk[parser_state_tos->tos - 1];
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case decl: /* finish of a declaration */
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case elsehead:
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/* <<if> <stmt> else> <stmt> */
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case forstmt:
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/* <for> <stmt> */
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case whilestmt:
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/* <while> <stmt> */
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parser_state_tos->p_stack[--parser_state_tos->tos] = stmt;
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parser_state_tos->i_l_follow = parser_state_tos->il[parser_state_tos->tos];
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break;
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default: /* <anything else> <stmt> */
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return;
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} /* end of section for <stmt> on top of stack */
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break;
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case whilestmt: /* while (...) on top */
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if (parser_state_tos->p_stack[parser_state_tos->tos - 1] == dohead) {
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/* it is termination of a do while */
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parser_state_tos->p_stack[--parser_state_tos->tos] = stmt;
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break;
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}
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else
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return;
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default: /* anything else on top */
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return;
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}
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}
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}
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