1 /* $NetBSD: parser.h,v 1.28 2019/02/13 21:40:50 kre Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)parser.h 8.3 (Berkeley) 5/4/95 35 */ 36 37 /* control characters in argument strings */ 38 #define CTL_FIRST '\201' /* first 'special' character */ 39 #define CTLESC '\201' /* escape next character */ 40 #define CTLVAR '\202' /* variable defn */ 41 #define CTLENDVAR '\203' 42 #define CTLBACKQ '\204' 43 #define CTLQUOTE 01 /* ored with CTLBACKQ code if in quotes */ 44 /* CTLBACKQ | CTLQUOTE == '\205' */ 45 #define CTLARI '\206' /* arithmetic expression */ 46 #define CTLENDARI '\207' 47 #define CTLQUOTEMARK '\210' 48 #define CTLQUOTEEND '\211' /* only inside ${...} */ 49 #define CTLNONL '\212' /* The \n in a deleted \ \n sequence */ 50 /* pure concidence that (CTLNONL & 0x7f) == '\n' */ 51 #define CTLCNL '\213' /* A $'\n' - newline not counted */ 52 #define CTL_LAST '\213' /* last 'special' character */ 53 54 /* variable substitution byte (follows CTLVAR) */ 55 #define VSTYPE 0x0f /* type of variable substitution */ 56 #define VSNUL 0x10 /* colon--treat the empty string as unset */ 57 #define VSLINENO 0x20 /* expansion of $LINENO, the line number 58 follows immediately */ 59 #define VSPATQ 0x40 /* ensure correct pattern quoting in ${x#pat} */ 60 #define VSQUOTE 0x80 /* inside double quotes--suppress splitting */ 61 62 /* values of VSTYPE field */ 63 #define VSNORMAL 0x1 /* normal variable: $var or ${var} */ 64 #define VSMINUS 0x2 /* ${var-text} */ 65 #define VSPLUS 0x3 /* ${var+text} */ 66 #define VSQUESTION 0x4 /* ${var?message} */ 67 #define VSASSIGN 0x5 /* ${var=text} */ 68 #define VSTRIMLEFT 0x6 /* ${var#pattern} */ 69 #define VSTRIMLEFTMAX 0x7 /* ${var##pattern} */ 70 #define VSTRIMRIGHT 0x8 /* ${var%pattern} */ 71 #define VSTRIMRIGHTMAX 0x9 /* ${var%%pattern} */ 72 #define VSLENGTH 0xa /* ${#var} */ 73 74 union node *parsecmd(int); 75 void fixredir(union node *, const char *, int); 76 int goodname(const char *); 77 int isassignment(const char *); 78 const char *getprompt(void *); 79 const char *expandstr(char *, int); 80 const char *expandenv(char *); 81 82 struct HereDoc; 83 union node; 84 struct nodelist; 85 86 struct parse_state { 87 struct HereDoc *ps_heredoclist; /* list of here documents to read */ 88 int ps_parsebackquote; /* nonzero inside backquotes */ 89 int ps_doprompt; /* if set, prompt the user */ 90 int ps_needprompt; /* true if interactive at line start */ 91 int ps_lasttoken; /* last token read */ 92 int ps_tokpushback; /* last token pushed back */ 93 char *ps_wordtext; /* text of last word returned by readtoken */ 94 int ps_checkkwd; /* word expansion flags, see below */ 95 struct nodelist *ps_backquotelist; /* list of cmdsubs to process */ 96 union node *ps_redirnode; /* node for current redirect */ 97 struct HereDoc *ps_heredoc; /* current heredoc << being parsed */ 98 int ps_quoteflag; /* set if (part) of token was quoted */ 99 int ps_startlinno; /* line # where last token started */ 100 int ps_funclinno; /* line # of the current function */ 101 int ps_elided_nl; /* count of \ \n pairs we have seen */ 102 }; 103 104 /* 105 * The parser references the elements of struct parse_state quite 106 * frequently - they used to be simple globals, so one memory ref 107 * per access, adding an indirect through a global ptr would not be 108 * nice. The following gross hack allows most of that cost to be 109 * avoided, by allowing the compiler to understand that the global 110 * pointer is in fact constant in any function, and so its value can 111 * be cached, rather than needing to be fetched every time in case 112 * some other called function has changed it. 113 * 114 * The rule to make this work is that any function that wants 115 * to alter the global must restore it before it returns (and thus 116 * must have an error trap handler). That means that the struct 117 * used for the new parser state can be a local in that function's 118 * stack frame, it never needs to be malloc'd. 119 */ 120 121 union parse_state_p { 122 struct parse_state *const c_current_parser; 123 struct parse_state * v_current_parser; 124 }; 125 126 extern union parse_state_p psp; 127 128 #define current_parser (psp.c_current_parser) 129 130 /* 131 * Perhaps one day emulate "static" by moving most of these definitions into 132 * parser.c ... (only checkkwd & tokpushback are used outside parser.c, 133 * and only in init.c as a RESET activity) 134 */ 135 #define tokpushback (current_parser->ps_tokpushback) 136 #define checkkwd (current_parser->ps_checkkwd) 137 138 #define heredoclist (current_parser->ps_heredoclist) 139 #define parsebackquote (current_parser->ps_parsebackquote) 140 #define doprompt (current_parser->ps_doprompt) 141 #define needprompt (current_parser->ps_needprompt) 142 #define lasttoken (current_parser->ps_lasttoken) 143 #define wordtext (current_parser->ps_wordtext) 144 #define backquotelist (current_parser->ps_backquotelist) 145 #define redirnode (current_parser->ps_redirnode) 146 #define heredoc (current_parser->ps_heredoc) 147 #define quoteflag (current_parser->ps_quoteflag) 148 #define startlinno (current_parser->ps_startlinno) 149 #define funclinno (current_parser->ps_funclinno) 150 #define elided_nl (current_parser->ps_elided_nl) 151 152 /* 153 * Values that can be set in checkkwd 154 */ 155 #define CHKKWD 0x01 /* turn word into keyword (if it is) */ 156 #define CHKNL 0x02 /* ignore leading \n's */ 157 #define CHKALIAS 0x04 /* lookup words as aliases and ... */ 158 159 /* 160 * NEOF is returned by parsecmd when it encounters an end of file. It 161 * must be distinct from NULL, so we use the address of a variable that 162 * happens to be handy. 163 */ 164 #define NEOF ((union node *)&psp) 165 166 #ifdef DEBUG 167 extern int parsing; 168 #endif 169