home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
minnie.tuhs.org
/
unixen.tar
/
unixen
/
PDP-11
/
Distributions
/
ucb
/
spencer_2bsd.tar.gz
/
2bsd.tar
/
src
/
pxp
/
yy.h
< prev
next >
Wrap
C/C++ Source or Header
|
1980-02-17
|
7KB
|
298 lines
/* Copyright (c) 1979 Regents of the University of California */
#
/*
* pi - Pascal interpreter code translator
*
* Charles Haley, Bill Joy UCB
* Version 1.1 February 1978
*
*
* pxp - Pascal execution profiler
*
* Bill Joy UCB
* Version 1.1 February 1978
*/
#include "y.tab.h"
/*
* INPUT/OUTPUT
*/
/*
* The buffer for the input file is normally "ibuf".
* When files are included, however, this may be
* pushed down in the stack of currently active
* files. For this reason, the pointer ibp always
* references the i/o buffer of the current input file.
*/
int ibuf[259], *ibp;
/*
* Line and token buffers. Charbuf is the character buffer for
* input lines, token the buffer for tokens returned
* by the scanner. CBSIZE defines the maximum line
* length allowed on input and is doubtless too small.
* The token buffer should be a local array in yylex.
*/
#define CBSIZE 161
char charbuf[CBSIZE], *bufp, token[CBSIZE];
#define digit(c) (c >= '0' && c <= '9')
#define alph(c) ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
/*
* Flag to prevent reprinting current line after
* an error.
*/
char yyprtd;
/*
* The following variables are maintained by
* the scanner in the file lex and used in scanning
* and in parsing.
*
* The variable yychar is the current scanner character.
* Currently, the scanner must be called as
* yychar = yylex()
* even though it should set yychar itself.
* Yychar has value YEOF at end of file, and negative value if
* there is no yychar, e.g. after a shift in the parser.
*
* The variable yycol is the current column in the line whose number
* is given by yyline. Yyecol and yyeline give the position for an
* error message to flag, usually the start of an input token.
* Yylval is the semantic return from the scanner.
*
* In fact all of these variables are "per token".
* In the usual case, only the copies in the scanner token structure
* 'Y' are used, and the #defines below serve to make them look
* like variables.
*
* For the purposes of the error recovery, however, they are copied
* and restored quite freely. For the error recovery also, the
* file name which the input line this token is on and the seek
* pointer of this line in its source file are saved as yyefile
* and yyseekp. The global variable yylinpt is the seek pointer
* of the current input line.
*/
int yycol;
int yyline;
int yyseqid;
int yysavc;
int yylinpt;
/* *** NOTE ***
* It would be much better to not have the Yyeline and Yyefile
* in the scanner structure and to have a mechanism for mapping
* seqid's to these globally.
*/
struct yytok {
int Yychar;
int Yylval;
int Yyecol;
int Yyeline;
int Yyseekp;
char *Yyefile;
int Yyeseqid;
} Y, OY;
#define yychar Y.Yychar
#define yylval Y.Yylval
#define yyecol Y.Yyecol
#define yyeline Y.Yyeline
#define yyseekp Y.Yyseekp
#define yyefile Y.Yyefile
#define yyeseqid Y.Yyeseqid
/*
* Yyval is the semantic value returned by a reduction.
* It is what "$$" is expanded to by yacc.
*/
int *Ps, *yyval;
/*
* N is the length of a reduction.
* Used externally by "lineof" to get the left and
* right margins for a reduction.
*/
int N;
/*
* Definitions for looking up keywords.
* The keyword array is called yykey, and
* lastkey points at the end of it.
*/
char *lastkey;
struct kwtab {
char *kw_str;
int kw_val;
} yykey[];
/*
* ERROR RECOVERY EXTERNALS
*/
#define CLIMIT 40 /* see yyrecover.c */
long tokname();
long charname();
char *classes[];
/*
* Tokens which yacc doesn't define
*/
#define YEOF 0
#define ERROR 256
/*
* Limit on the number of syntax errors
*/
#define MAXSYNERR 100
/*
* Big costs
*/
#define HUGE 50
#define INFINITY 100
/*
* Kinds of panics
*/
#define PDECL 0
#define PSTAT 1
#define PEXPR 2
#define PPROG 3
#define yyresume() yyResume = 1;
char yyResume;
char dquote;
char errout;
/*
* Yyidwant and yyidhave are the namelist classes
* of identifiers associated with a identifier reduce
* error, set before the recovery is called.
* Since they may be set again during the forward move
* they must be saved by yyrecover, which uses them in printing
* error messages.
*/
int yyidhave, yyidwant;
/*
* The variables yy*shifts are used to prevent looping and the printing
* of spurious messages in the parser. Yyshifts gives the number of
* true input shifts since the last corrective action. YyOshifts
* is the value of yyshifts before it was last cleared, and is used
* by yyPerror in yypanic.c to suppress messages.
*
* Yytshifts counts true input shifts. It is used to prevent looping
* inserting unique symbols. If yytshifts == yyTshifts (local to
* yyrecover.c) then there has been no shift over true input since
* the last unique symbol insertion. We refuse, in this case,
* to insert more unique symbols so as to prevent looping.
*
* The recovery cannot loop because it guarantees the progress of the
* parse, i.e.:
*
* 1) Any insertion guarantees to shift over 2 symbols, a replacement
* over one symbol.
*
* 2) Unique symbol insertions are limited to one for each true
* symbol of input, or "safe" insertion of the keywords "end"
* and "until" at zero cost (safe since these are know to match
* stack that cannot have been generated - e.g. "begin" or "repeat")
*
* 3) We never panic more than once from a given state without
* shifting over input, i.e. we force the parse stack to shrink
* after each unsuccessful panic.
*/
int yyshifts, yyOshifts;
unsigned yytshifts;
#ifdef PXP
/*
* Identifier class definitions
*/
#define UNDEF 0
#define CONST 1
#define TYPE 2
#define VAR 3
#define ARRAY 4
#define PTRFILE 5
#define RECORD 6
#define FIELD 7
#define PROC 8
#define FUNC 9
#define FVAR 10
#define REF 11
#define PTR 12
#define FILE 13
#define SET 14
#define RANGE 15
#define LABEL 16
#define WITHPTR 17
#define SCAL 18
#define STR 19
#define PROG 20
#define IMPROPER 21
/*
* COMMENT FORMATTING DEFINITIONS
*/
/*
* Count of tokens on this input line
* Note that this can be off if input is not syntactically correct.
*/
int yytokcnt;
int yywhcnt;
/*
* Types of comments
*/
#define CLMARG 0
#define CALIGN 1
#define CTRAIL 2
#define CRMARG 3
#define CSRMARG 4
#define CNL 5
#define CNLBL 6
#define CFORM 7
#define CINCLUD 8
/*
* Comment structure
* Cmhp is the head of the current list of comments
*/
struct comment {
struct comment *cmnext;
int cmdelim;
struct commline *cml;
int cmjust;
int cmseqid;
} *cmhp;
/*
* Structure for holding a comment line
*/
struct commline {
char *cmtext;
int cmcol; /* Only used for first line of comment currently */
struct commline *cml;
};
struct W {
int Wseqid;
int Wcol;
} yyw[MAXDEPTH + 1], *yypw;
#define commform() quickcomm(CFORM)
#define commnl() quickcomm(CNL)
#define commnlbl() quickcomm(CNLBL)
#endif