1/*    parser.h
2 *
3 *    Copyright (c) 2006, 2007, 2009, 2010, 2011 Larry Wall and others
4 *
5 *    You may distribute under the terms of either the GNU General Public
6 *    License or the Artistic License, as specified in the README file.
7 *
8 * This file defines the layout of the parser object used by the parser
9 * and lexer (perly.c, toke.c).
10 */
11
12#define YYEMPTY		(-2)
13
14typedef struct {
15    YYSTYPE val;    /* semantic value */
16    short   state;
17    I32     savestack_ix;	/* size of savestack at this state */
18    CV	    *compcv; /* value of PL_compcv when this value was created */
19#ifdef DEBUGGING
20    const char  *name; /* token/rule name for -Dpv */
21#endif
22} yy_stack_frame;
23
24/* Fields that need to be shared with (i.e., visible to) inner lex-
25   ing scopes. */
26typedef struct yy_lexshared {
27    struct yy_lexshared	*ls_prev;
28    SV			*ls_linestr;	/* mirrors PL_parser->linestr */
29    char		*ls_bufptr;	/* mirrors PL_parser->bufptr */
30    char		*re_eval_start;	/* start of "(?{..." text */
31    SV			*re_eval_str;	/* "(?{...})" text */
32} LEXSHARED;
33
34typedef struct yy_parser {
35
36    /* parser state */
37
38    struct yy_parser *old_parser; /* previous value of PL_parser */
39    YYSTYPE	    yylval;	/* value of lookahead symbol, set by yylex() */
40    int		    yychar;	/* The lookahead symbol.  */
41
42    /* Number of tokens to shift before error messages enabled.  */
43    int		    yyerrstatus;
44
45    yy_stack_frame  *stack;	/* base of stack */
46    yy_stack_frame  *stack_max1;/* (top-1)th element of allocated stack */
47    yy_stack_frame  *ps;	/* current stack frame */
48    int		    yylen;	/* length of active reduction */
49
50    /* lexer state */
51
52    I32		lex_formbrack;	/* bracket count at outer format level */
53    I32		lex_brackets;	/* square and curly bracket count */
54    I32		lex_casemods;	/* casemod count */
55    char	*lex_brackstack;/* what kind of brackets to pop */
56    char	*lex_casestack;	/* what kind of case mods in effect */
57    U8		lex_defer;	/* state after determined token */
58    U8		lex_dojoin;	/* doing an array interpolation
59                                   1 = @{...}  2 = ->@ */
60    U8		expect;		/* how to interpret ambiguous tokens */
61    bool	preambled;
62    bool        sub_no_recover; /* can't recover from a sublex error */
63    U8		sub_error_count; /* the number of errors before sublexing */
64    OP		*lex_inpat;	/* in pattern $) and $| are special */
65    OP		*lex_op;	/* extra info to pass back on op */
66    SV		*lex_repl;	/* runtime replacement from s/// */
67    U16		lex_inwhat;	/* what kind of quoting are we in */
68    OPCODE	last_lop_op;	/* last named list or unary operator */
69    I32		lex_starts;	/* how many interps done on level */
70    SV		*lex_stuff;	/* runtime pattern from m// or s/// */
71    I32		multi_start;	/* 1st line of multi-line string */
72    I32		multi_end;	/* last line of multi-line string */
73    UV		multi_open;	/* delimiter code point of said string */
74    UV		multi_close;	/* delimiter code point of said string */
75    bool        lex_re_reparsing; /* we're doing G_RE_REPARSING */
76    U8		lex_super_state;/* lexer state to save */
77    U16		lex_sub_inwhat;	/* "lex_inwhat" to use in sublex_push */
78    I32		lex_allbrackets;/* (), [], {}, ?: bracket count */
79    OP		*lex_sub_op;	/* current op in y/// or pattern */
80    SV		*lex_sub_repl;	/* repl of s/// used in sublex_push */
81    LEXSHARED	*lex_shared;
82    SV		*linestr;	/* current chunk of src text */
83    char	*bufptr;	/* carries the cursor (current parsing
84                                   position) from one invocation of yylex
85                                   to the next */
86    char	*oldbufptr;	/* in yylex, beginning of current token */
87    char	*oldoldbufptr;	/* in yylex, beginning of previous token */
88    char	*bufend;
89    char	*linestart;	/* beginning of most recently read line */
90    char	*last_uni;	/* position of last named-unary op */
91    char	*last_lop;	/* position of last list operator */
92    /* copline is used to pass a specific line number to newSTATEOP.  It
93       is a one-time line number, as newSTATEOP invalidates it (sets it to
94       NOLINE) after using it.  The purpose of this is to report line num-
95       bers in multiline constructs using the number of the first line. */
96    line_t	copline;
97    U16		in_my;		/* we're compiling a "my"/"our" declaration */
98    U8		lex_state;	/* next token is determined */
99    U8		error_count;	/* how many compile errors so far, max 10 */
100    HV		*in_my_stash;	/* declared class of this "my" declaration */
101    PerlIO	*rsfp;		/* current source file pointer */
102    AV		*rsfp_filters;	/* holds chain of active source filters */
103
104    YYSTYPE	nextval[5];	/* value of next token, if any */
105    I32		nexttype[5];	/* type of next token */
106    U8		nexttoke;
107    U8		form_lex_state;	/* remember lex_state when parsing fmt */
108    U8		lex_fakeeof;	/* precedence at which to fake EOF */
109    U8		lex_flags;
110    COP		*saved_curcop;	/* the previous PL_curcop */
111    char	tokenbuf[256];
112    line_t	herelines;	/* number of lines in here-doc */
113    line_t	preambling;	/* line # when processing $ENV{PERL5DB} */
114
115    /* these are valid while parsing a subroutine signature */
116    UV          sig_elems;      /* number of signature elements seen so far */
117    UV          sig_optelems;   /* number of optional signature elems seen */
118    char        sig_slurpy;     /* the sigil of the slurpy var (or null) */
119    bool        sig_seen;       /* the currently parsing sub has a signature */
120
121    bool        recheck_utf8_validity;
122
123    PERL_BITFIELD16	in_pod:1;      /* lexer is within a =pod section */
124    PERL_BITFIELD16	filtered:1;    /* source filters in evalbytes */
125    PERL_BITFIELD16	saw_infix_sigil:1; /* saw & or * or % operator */
126    PERL_BITFIELD16	parsed_sub:1;  /* last thing parsed was a sub */
127} yy_parser;
128
129/* flags for lexer API */
130#define LEX_STUFF_UTF8		0x00000001
131#define LEX_KEEP_PREVIOUS	0x00000002
132
133#ifdef PERL_CORE
134# define LEX_START_SAME_FILTER	0x00000001
135# define LEX_IGNORE_UTF8_HINTS	0x00000002
136# define LEX_EVALBYTES		0x00000004
137# define LEX_START_COPIED	0x00000008
138# define LEX_DONT_CLOSE_RSFP	0x00000010
139# define LEX_START_FLAGS \
140        (LEX_START_SAME_FILTER|LEX_START_COPIED \
141        |LEX_IGNORE_UTF8_HINTS|LEX_EVALBYTES|LEX_DONT_CLOSE_RSFP)
142#endif
143
144/* flags for parser API */
145#define PARSE_OPTIONAL          0x00000001
146
147/* values for lex_fakeeof */
148enum {
149    LEX_FAKEEOF_NEVER,      /* don't fake EOF */
150    LEX_FAKEEOF_CLOSING,    /* fake EOF at unmatched closing punctuation */
151    LEX_FAKEEOF_NONEXPR,    /* ... and at token that can't be in expression */
152    LEX_FAKEEOF_LOWLOGIC,   /* ... and at low-precedence logic operator */
153    LEX_FAKEEOF_COMMA,      /* ... and at comma */
154    LEX_FAKEEOF_ASSIGN,     /* ... and at assignment operator */
155    LEX_FAKEEOF_IFELSE,     /* ... and at ?: operator */
156    LEX_FAKEEOF_RANGE,      /* ... and at range operator */
157    LEX_FAKEEOF_LOGIC,      /* ... and at logic operator */
158    LEX_FAKEEOF_BITWISE,    /* ... and at bitwise operator */
159    LEX_FAKEEOF_COMPARE,    /* ... and at comparison operator */
160    LEX_FAKEEOF_MAX
161};
162
163/*
164 * ex: set ts=8 sts=4 sw=4 et:
165 */
166