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authorJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
committerJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
commit40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch)
tree4464880c571602d54f6ae114729bf62a89518057 /unix/boot/xyacc/yaccpar.x
downloadiraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz
Repatch (from linux) of OSX IRAF
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+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+# Parser for yacc output, translated to the IRAF SPP language. The contents
+# of this file form the bulk of the source of the parser produced by Yacc.
+# Yacc recognizes several macros in the yaccpar input source and replaces
+# them as follows:
+# A user suppled "global" definitions and declarations
+# B parser tables
+# C user supplied actions (reductions)
+# The remainder of the yaccpar code is not changed.
+
+define yystack_ 10 # statement labels for gotos
+define yynewstate_ 20
+define yydefault_ 30
+define yyerrlab_ 40
+define yyabort_ 50
+
+define YYFLAG (-1000) # defs used in user actions
+define YYERROR goto yyerrlab_
+define YYACCEPT return (OK)
+define YYABORT return (ERR)
+
+
+# YYPARSE -- Parse the input stream, returning OK if the source is
+# syntactically acceptable (i.e., if compilation is successful),
+# otherwise ERR. The parameters YYMAXDEPTH and YYOPLEN must be
+# supplied by the caller in the %{ ... %} section of the Yacc source.
+# The token value stack is a dynamically allocated array of operand
+# structures, with the length and makeup of the operand structure being
+# application dependent.
+
+int procedure yyparse (fd, yydebug, yylex)
+
+int fd # stream to be parsed
+bool yydebug # print debugging information?
+int yylex() # user-supplied lexical input function
+extern yylex()
+
+short yys[YYMAXDEPTH] # parser stack -- stacks tokens
+pointer yyv # pointer to token value stack
+pointer yyval # value returned by action
+pointer yylval # value of token
+int yyps # token stack pointer
+pointer yypv # value stack pointer
+int yychar # current input token number
+int yyerrflag # error recovery flag
+int yynerrs # number of errors
+
+short yyj, yym # internal variables
+pointer yysp, yypvt
+short yystate, yyn
+int yyxi, i
+errchk salloc, yylex
+
+$A # User declarations go here.
+$B # YACC parser tables defining the finite automaton go here.
+
+begin
+ call smark (yysp)
+ call salloc (yyv, (YYMAXDEPTH+2) * YYOPLEN, TY_STRUCT)
+
+ # Initialization. The first element of the dynamically allocated
+ # token value stack (yyv) is used for yyval, the second for yylval,
+ # and the actual stack starts with the third element.
+
+ yystate = 0
+ yychar = -1
+ yynerrs = 0
+ yyerrflag = 0
+ yyps = 0
+ yyval = yyv
+ yylval = yyv + YYOPLEN
+ yypv = yylval
+
+yystack_
+ # SHIFT -- Put a state and value onto the stack. The token and
+ # value stacks are logically the same stack, implemented as two
+ # separate arrays.
+
+ if (yydebug) {
+ call printf ("state %d, char 0%o\n")
+ call pargs (yystate)
+ call pargi (yychar)
+ }
+ yyps = yyps + 1
+ yypv = yypv + YYOPLEN
+ if (yyps > YYMAXDEPTH) {
+ call sfree (yysp)
+ call eprintf ("yacc stack overflow\n")
+ return (ERR)
+ }
+ yys[yyps] = yystate
+ YYMOVE (yyval, yypv)
+
+yynewstate_
+ # Process the new state.
+ yyn = yypact[yystate+1]
+
+ if (yyn <= YYFLAG)
+ goto yydefault_ # simple state
+
+ # The variable "yychar" is the lookahead token.
+ if (yychar < 0) {
+ yychar = yylex (fd, yylval)
+ if (yychar < 0)
+ yychar = 0
+ }
+ yyn = yyn + yychar
+ if (yyn < 0 || yyn >= YYLAST)
+ goto yydefault_
+
+ yyn = yyact[yyn+1]
+ if (yychk[yyn+1] == yychar) { # valid shift
+ yychar = -1
+ YYMOVE (yylval, yyval)
+ yystate = yyn
+ if (yyerrflag > 0)
+ yyerrflag = yyerrflag - 1
+ goto yystack_
+ }
+
+yydefault_
+ # Default state action.
+
+ yyn = yydef[yystate+1]
+ if (yyn == -2) {
+ if (yychar < 0) {
+ yychar = yylex (fd, yylval)
+ if (yychar < 0)
+ yychar = 0
+ }
+
+ # Look through exception table.
+ yyxi = 1
+ while ((yyexca[yyxi] != (-1)) || (yyexca[yyxi+1] != yystate))
+ yyxi = yyxi + 2
+ for (yyxi=yyxi+2; yyexca[yyxi] >= 0; yyxi=yyxi+2) {
+ if (yyexca[yyxi] == yychar)
+ break
+ }
+
+ yyn = yyexca[yyxi+1]
+ if (yyn < 0) {
+ call sfree (yysp)
+ return (OK) # ACCEPT -- all done
+ }
+ }
+
+
+ # SYNTAX ERROR -- resume parsing if possible.
+
+ if (yyn == 0) {
+ switch (yyerrflag) {
+ case 0, 1, 2:
+ if (yyerrflag == 0) { # brand new error
+ call eprintf ("syntax error\n")
+yyerrlab_
+ yynerrs = yynerrs + 1
+ # fall through...
+ }
+
+ # case 1:
+ # case 2: incompletely recovered error ... try again
+ yyerrflag = 3
+
+ # Find a state where "error" is a legal shift action.
+ while (yyps >= 1) {
+ yyn = yypact[yys[yyps]+1] + YYERRCODE
+ if ((yyn >= 0) && (yyn < YYLAST) &&
+ (yychk[yyact[yyn+1]+1] == YYERRCODE)) {
+ # Simulate a shift of "error".
+ yystate = yyact[yyn+1]
+ goto yystack_
+ }
+ yyn = yypact[yys[yyps]+1]
+
+ # The current yyps has no shift on "error", pop stack.
+ if (yydebug) {
+ call printf ("error recovery pops state %d, ")
+ call pargs (yys[yyps])
+ call printf ("uncovers %d\n")
+ call pargs (yys[yyps-1])
+ }
+ yyps = yyps - 1
+ yypv = yypv - YYOPLEN
+ }
+
+ # ABORT -- There is no state on the stack with an error shift.
+yyabort_
+ call sfree (yysp)
+ return (ERR)
+
+
+ case 3: # No shift yet; clobber input char.
+
+ if (yydebug) {
+ call printf ("error recovery discards char %d\n")
+ call pargi (yychar)
+ }
+
+ if (yychar == 0)
+ goto yyabort_ # don't discard EOF, quit
+ yychar = -1
+ goto yynewstate_ # try again in the same state
+ }
+ }
+
+
+ # REDUCE -- Reduction by production yyn.
+
+ if (yydebug) {
+ call printf ("reduce %d\n")
+ call pargs (yyn)
+ }
+ yyps = yyps - yyr2[yyn+1]
+ yypvt = yypv
+ yypv = yypv - yyr2[yyn+1] * YYOPLEN
+ YYMOVE (yypv + YYOPLEN, yyval)
+ yym = yyn
+
+ # Consult goto table to find next state.
+ yyn = yyr1[yyn+1]
+ yyj = yypgo[yyn+1] + yys[yyps] + 1
+ if (yyj >= YYLAST)
+ yystate = yyact[yypgo[yyn+1]+1]
+ else {
+ yystate = yyact[yyj+1]
+ if (yychk[yystate+1] != -yyn)
+ yystate = yyact[yypgo[yyn+1]+1]
+ }
+
+ # Perform action associated with the grammar rule, if any.
+ switch (yym) {
+ $C # YACC replaces this line by the user supplied actions.
+ }
+
+ goto yystack_ # stack new state and value
+end