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Diffstat (limited to 'scripts/unifdef.c')
| -rw-r--r-- | scripts/unifdef.c | 1005 |
1 files changed, 1005 insertions, 0 deletions
diff --git a/scripts/unifdef.c b/scripts/unifdef.c new file mode 100644 index 00000000000..552025e72ac --- /dev/null +++ b/scripts/unifdef.c @@ -0,0 +1,1005 @@ +/* + * Copyright (c) 2002 - 2005 Tony Finch <dot@dotat.at>. All rights reserved. + * + * This code is derived from software contributed to Berkeley by Dave Yost. + * It was rewritten to support ANSI C by Tony Finch. The original version of + * unifdef carried the following copyright notice. None of its code remains + * in this version (though some of the names remain). + * + * Copyright (c) 1985, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> + +#ifndef lint +#if 0 +static const char copyright[] = +"@(#) Copyright (c) 1985, 1993\n\ + The Regents of the University of California. All rights reserved.\n"; +#endif +#ifdef __IDSTRING +__IDSTRING(Berkeley, "@(#)unifdef.c 8.1 (Berkeley) 6/6/93"); +__IDSTRING(NetBSD, "$NetBSD: unifdef.c,v 1.8 2000/07/03 02:51:36 matt Exp $"); +__IDSTRING(dotat, "$dotat: things/unifdef.c,v 1.171 2005/03/08 12:38:48 fanf2 Exp $"); +#endif +#endif /* not lint */ +#ifdef __FBSDID +__FBSDID("$FreeBSD: /repoman/r/ncvs/src/usr.bin/unifdef/unifdef.c,v 1.20 2005/05/21 09:55:09 ru Exp $"); +#endif + +/* + * unifdef - remove ifdef'ed lines + * + * Wishlist: + * provide an option which will append the name of the + * appropriate symbol after #else's and #endif's + * provide an option which will check symbols after + * #else's and #endif's to see that they match their + * corresponding #ifdef or #ifndef + * + * The first two items above require better buffer handling, which would + * also make it possible to handle all "dodgy" directives correctly. + */ + +#include <ctype.h> +#include <err.h> +#include <stdarg.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +size_t strlcpy(char *dst, const char *src, size_t siz); + +/* types of input lines: */ +typedef enum { + LT_TRUEI, /* a true #if with ignore flag */ + LT_FALSEI, /* a false #if with ignore flag */ + LT_IF, /* an unknown #if */ + LT_TRUE, /* a true #if */ + LT_FALSE, /* a false #if */ + LT_ELIF, /* an unknown #elif */ + LT_ELTRUE, /* a true #elif */ + LT_ELFALSE, /* a false #elif */ + LT_ELSE, /* #else */ + LT_ENDIF, /* #endif */ + LT_DODGY, /* flag: directive is not on one line */ + LT_DODGY_LAST = LT_DODGY + LT_ENDIF, + LT_PLAIN, /* ordinary line */ + LT_EOF, /* end of file */ + LT_COUNT +} Linetype; + +static char const * const linetype_name[] = { + "TRUEI", "FALSEI", "IF", "TRUE", "FALSE", + "ELIF", "ELTRUE", "ELFALSE", "ELSE", "ENDIF", + "DODGY TRUEI", "DODGY FALSEI", + "DODGY IF", "DODGY TRUE", "DODGY FALSE", + "DODGY ELIF", "DODGY ELTRUE", "DODGY ELFALSE", + "DODGY ELSE", "DODGY ENDIF", + "PLAIN", "EOF" +}; + +/* state of #if processing */ +typedef enum { + IS_OUTSIDE, + IS_FALSE_PREFIX, /* false #if followed by false #elifs */ + IS_TRUE_PREFIX, /* first non-false #(el)if is true */ + IS_PASS_MIDDLE, /* first non-false #(el)if is unknown */ + IS_FALSE_MIDDLE, /* a false #elif after a pass state */ + IS_TRUE_MIDDLE, /* a true #elif after a pass state */ + IS_PASS_ELSE, /* an else after a pass state */ + IS_FALSE_ELSE, /* an else after a true state */ + IS_TRUE_ELSE, /* an else after only false states */ + IS_FALSE_TRAILER, /* #elifs after a true are false */ + IS_COUNT +} Ifstate; + +static char const * const ifstate_name[] = { + "OUTSIDE", "FALSE_PREFIX", "TRUE_PREFIX", + "PASS_MIDDLE", "FALSE_MIDDLE", "TRUE_MIDDLE", + "PASS_ELSE", "FALSE_ELSE", "TRUE_ELSE", + "FALSE_TRAILER" +}; + +/* state of comment parser */ +typedef enum { + NO_COMMENT = false, /* outside a comment */ + C_COMMENT, /* in a comment like this one */ + CXX_COMMENT, /* between // and end of line */ + STARTING_COMMENT, /* just after slash-backslash-newline */ + FINISHING_COMMENT, /* star-backslash-newline in a C comment */ + CHAR_LITERAL, /* inside '' */ + STRING_LITERAL /* inside "" */ +} Comment_state; + +static char const * const comment_name[] = { + "NO", "C", "CXX", "STARTING", "FINISHING", "CHAR", "STRING" +}; + +/* state of preprocessor line parser */ +typedef enum { + LS_START, /* only space and comments on this line */ + LS_HASH, /* only space, comments, and a hash */ + LS_DIRTY /* this line can't be a preprocessor line */ +} Line_state; + +static char const * const linestate_name[] = { + "START", "HASH", "DIRTY" +}; + +/* + * Minimum translation limits from ISO/IEC 9899:1999 5.2.4.1 + */ +#define MAXDEPTH 64 /* maximum #if nesting */ +#define MAXLINE 4096 /* maximum length of line */ +#define MAXSYMS 4096 /* maximum number of symbols */ + +/* + * Sometimes when editing a keyword the replacement text is longer, so + * we leave some space at the end of the tline buffer to accommodate this. + */ +#define EDITSLOP 10 + +/* + * Globals. + */ + +static bool complement; /* -c: do the complement */ +static bool debugging; /* -d: debugging reports */ +static bool iocccok; /* -e: fewer IOCCC errors */ +static bool killconsts; /* -k: eval constant #ifs */ +static bool lnblank; /* -l: blank deleted lines */ +static bool lnnum; /* -n: add #line directives */ +static bool symlist; /* -s: output symbol list */ +static bool text; /* -t: this is a text file */ + +static const char *symname[MAXSYMS]; /* symbol name */ +static const char *value[MAXSYMS]; /* -Dsym=value */ +static bool ignore[MAXSYMS]; /* -iDsym or -iUsym */ +static int nsyms; /* number of symbols */ + +static FILE *input; /* input file pointer */ +static const char *filename; /* input file name */ +static int linenum; /* current line number */ + +static char tline[MAXLINE+EDITSLOP];/* input buffer plus space */ +static char *keyword; /* used for editing #elif's */ + +static Comment_state incomment; /* comment parser state */ +static Line_state linestate; /* #if line parser state */ +static Ifstate ifstate[MAXDEPTH]; /* #if processor state */ +static bool ignoring[MAXDEPTH]; /* ignore comments state */ +static int stifline[MAXDEPTH]; /* start of current #if */ +static int depth; /* current #if nesting */ +static int delcount; /* count of deleted lines */ +static bool keepthis; /* don't delete constant #if */ + +static int exitstat; /* program exit status */ + +static void addsym(bool, bool, char *); +static void debug(const char *, ...); +static void done(void); +static void error(const char *); +static int findsym(const char *); +static void flushline(bool); +static Linetype getline(void); +static Linetype ifeval(const char **); +static void ignoreoff(void); +static void ignoreon(void); +static void keywordedit(const char *); +static void nest(void); +static void process(void); +static const char *skipcomment(const char *); +static const char *skipsym(const char *); +static void state(Ifstate); +static int strlcmp(const char *, const char *, size_t); +static void unnest(void); +static void usage(void); + +#define endsym(c) (!isalpha((unsigned char)c) && !isdigit((unsigned char)c) && c != '_') + +/* + * The main program. + */ +int +main(int argc, char *argv[]) +{ + int opt; + + while ((opt = getopt(argc, argv, "i:D:U:I:cdeklnst")) != -1) + switch (opt) { + case 'i': /* treat stuff controlled by these symbols as text */ + /* + * For strict backwards-compatibility the U or D + * should be immediately after the -i but it doesn't + * matter much if we relax that requirement. + */ + opt = *optarg++; + if (opt == 'D') + addsym(true, true, optarg); + else if (opt == 'U') + addsym(true, false, optarg); + else + usage(); + break; + case 'D': /* define a symbol */ + addsym(false, true, optarg); + break; + case 'U': /* undef a symbol */ + addsym(false, false, optarg); + break; + case 'I': + /* no-op for compatibility with cpp */ + break; + case 'c': /* treat -D as -U and vice versa */ + complement = true; + break; + case 'd': + debugging = true; + break; + case 'e': /* fewer errors from dodgy lines */ + iocccok = true; + break; + case 'k': /* process constant #ifs */ + killconsts = true; + break; + case 'l': /* blank deleted lines instead of omitting them */ + lnblank = true; + break; + case 'n': /* add #line directive after deleted lines */ + lnnum = true; + break; + case 's': /* only output list of symbols that control #ifs */ + symlist = true; + break; + case 't': /* don't parse C comments */ + text = true; + break; + default: + usage(); + } + argc -= optind; + argv += optind; + if (argc > 1) { + errx(2, "can only do one file"); + } else if (argc == 1 && strcmp(*argv, "-") != 0) { + filename = *argv; + input = fopen(filename, "r"); + if (input == NULL) + err(2, "can't open %s", filename); + } else { + filename = "[stdin]"; + input = stdin; + } + process(); + abort(); /* bug */ +} + +static void +usage(void) +{ + fprintf(stderr, "usage: unifdef [-cdeklnst] [-Ipath]" + " [-Dsym[=val]] [-Usym] [-iDsym[=val]] [-iUsym] ... [file]\n"); + exit(2); +} + +/* + * A state transition function alters the global #if processing state + * in a particular way. The table below is indexed by the current + * processing state and the type of the current line. + * + * Nesting is handled by keeping a stack of states; some transition + * functions increase or decrease the depth. They also maintain the + * ignore state on a stack. In some complicated cases they have to + * alter the preprocessor directive, as follows. + * + * When we have processed a group that starts off with a known-false + * #if/#elif sequence (which has therefore been deleted) followed by a + * #elif that we don't understand and therefore must keep, we edit the + * latter into a #if to keep the nesting correct. + * + * When we find a true #elif in a group, the following block will + * always be kept and the rest of the sequence after the next #elif or + * #else will be discarded. We edit the #elif into a #else and the + * following directive to #endif since this has the desired behaviour. + * + * "Dodgy" directives are split across multiple lines, the most common + * example being a multi-line comment hanging off the right of the + * directive. We can handle them correctly only if there is no change + * from printing to dropping (or vice versa) caused by that directive. + * If the directive is the first of a group we have a choice between + * failing with an error, or passing it through unchanged instead of + * evaluating it. The latter is not the default to avoid questions from + * users about unifdef unexpectedly leaving behind preprocessor directives. + */ +typedef void state_fn(void); + +/* report an error */ +static void Eelif (void) { error("Inappropriate #elif"); } +static void Eelse (void) { error("Inappropriate #else"); } +static void Eendif(void) { error("Inappropriate #endif"); } +static void Eeof (void) { error("Premature EOF"); } +static void Eioccc(void) { error("Obfuscated preprocessor control line"); } +/* plain line handling */ +static void print (void) { flushline(true); } +static void drop (void) { flushline(false); } +/* output lacks group's start line */ +static void Strue (void) { drop(); ignoreoff(); state(IS_TRUE_PREFIX); } +static void Sfalse(void) { drop(); ignoreoff(); state(IS_FALSE_PREFIX); } +static void Selse (void) { drop(); state(IS_TRUE_ELSE); } +/* print/pass this block */ +static void Pelif (void) { print(); ignoreoff(); state(IS_PASS_MIDDLE); } +static void Pelse (void) { print(); state(IS_PASS_ELSE); } +static void Pendif(void) { print(); unnest(); } +/* discard this block */ +static void Dfalse(void) { drop(); ignoreoff(); state(IS_FALSE_TRAILER); } +static void Delif (void) { drop(); ignoreoff(); state(IS_FALSE_MIDDLE); } +static void Delse (void) { drop(); state(IS_FALSE_ELSE); } +static void Dendif(void) { drop(); unnest(); } +/* first line of group */ +static void Fdrop (void) { nest(); Dfalse(); } +static void Fpass (void) { nest(); Pelif(); } +static void Ftrue (void) { nest(); Strue(); } +static void Ffalse(void) { nest(); Sfalse(); } +/* variable pedantry for obfuscated lines */ +static void Oiffy (void) { if (!iocccok) Eioccc(); Fpass(); ignoreon(); } +static void Oif (void) { if (!iocccok) Eioccc(); Fpass(); } +static void Oelif (void) { if (!iocccok) Eioccc(); Pelif(); } +/* ignore comments in this block */ +static void Idrop (void) { Fdrop(); ignoreon(); } +static void Itrue (void) { Ftrue(); ignoreon(); } +static void Ifalse(void) { Ffalse(); ignoreon(); } +/* edit this line */ +static void Mpass (void) { strncpy(keyword, "if ", 4); Pelif(); } +static void Mtrue (void) { keywordedit("else\n"); state(IS_TRUE_MIDDLE); } +static void Melif (void) { keywordedit("endif\n"); state(IS_FALSE_TRAILER); } +static void Melse (void) { keywordedit("endif\n"); state(IS_FALSE_ELSE); } + +static state_fn * const trans_table[IS_COUNT][LT_COUNT] = { +/* IS_OUTSIDE */ +{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Eendif, + Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Eendif, + print, done }, +/* IS_FALSE_PREFIX */ +{ Idrop, Idrop, Fdrop, Fdrop, Fdrop, Mpass, Strue, Sfalse,Selse, Dendif, + Idrop, Idrop, Fdrop, Fdrop, Fdrop, Mpass, Eioccc,Eioccc,Eioccc,Eioccc, + drop, Eeof }, +/* IS_TRUE_PREFIX */ +{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Dfalse,Dfalse,Dfalse,Delse, Dendif, + Oiffy, Oiffy, Fpass, Oif, Oif, Eioccc,Eioccc,Eioccc,Eioccc,Eioccc, + print, Eeof }, +/* IS_PASS_MIDDLE */ +{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Pelif, Mtrue, Delif, Pelse, Pendif, + Oiffy, Oiffy, Fpass, Oif, Oif, Pelif, Oelif, Oelif, Pelse, Pendif, + print, Eeof }, +/* IS_FALSE_MIDDLE */ +{ Idrop, Idrop, Fdrop, Fdrop, Fdrop, Pelif, Mtrue, Delif, Pelse, Pendif, + Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eioccc,Eioccc,Eioccc,Eioccc,Eioccc, + drop, Eeof }, +/* IS_TRUE_MIDDLE */ +{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Melif, Melif, Melif, Melse, Pendif, + Oiffy, Oiffy, Fpass, Oif, Oif, Eioccc,Eioccc,Eioccc,Eioccc,Pendif, + print, Eeof }, +/* IS_PASS_ELSE */ +{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Pendif, + Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Pendif, + print, Eeof }, +/* IS_FALSE_ELSE */ +{ Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eelif, Eelif, Eelif, Eelse, Dendif, + Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eelif, Eelif, Eelif, Eelse, Eioccc, + drop, Eeof }, +/* IS_TRUE_ELSE */ +{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Dendif, + Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Eioccc, + print, Eeof }, +/* IS_FALSE_TRAILER */ +{ Idrop, Idrop, Fdrop, Fdrop, Fdrop, Dfalse,Dfalse,Dfalse,Delse, Dendif, + Idrop, Idrop, Fdrop, Fdrop, Fdrop, Dfalse,Dfalse,Dfalse,Delse, Eioccc, + drop, Eeof } +/*TRUEI FALSEI IF TRUE FALSE ELIF ELTRUE ELFALSE ELSE ENDIF + TRUEI FALSEI IF TRUE FALSE ELIF ELTRUE ELFALSE ELSE ENDIF (DODGY) + PLAIN EOF */ +}; + +/* + * State machine utility functions + */ +static void +done(void) +{ + if (incomment) + error("EOF in comment"); + exit(exitstat); +} +static void +ignoreoff(void) +{ + if (depth == 0) + abort(); /* bug */ + ignoring[depth] = ignoring[depth-1]; +} +static void +ignoreon(void) +{ + ignoring[depth] = true; +} +static void +keywordedit(const char *replacement) +{ + size_t size = tline + sizeof(tline) - keyword; + char *dst = keyword; + const char *src = replacement; + if (size != 0) { + while ((--size != 0) && (*src != '\0')) + *dst++ = *src++; + *dst = '\0'; + } + print(); +} +static void +nest(void) +{ + depth += 1; + if (depth >= MAXDEPTH) + error("Too many levels of nesting"); + stifline[depth] = linenum; +} +static void +unnest(void) +{ + if (depth == 0) + abort(); /* bug */ + depth -= 1; +} +static void +state(Ifstate is) +{ + ifstate[depth] = is; +} + +/* + * Write a line to the output or not, according to command line options. + */ +static void +flushline(bool keep) +{ + if (symlist) + return; + if (keep ^ complement) { + if (lnnum && delcount > 0) + printf("#line %d\n", linenum); + fputs(tline, stdout); + delcount = 0; + } else { + if (lnblank) + putc('\n', stdout); + exitstat = 1; + delcount += 1; + } +} + +/* + * The driver for the state machine. + */ +static void +process(void) +{ + Linetype lineval; + + for (;;) { + linenum++; + lineval = getline(); + trans_table[ifstate[depth]][lineval](); + debug("process %s -> %s depth %d", + linetype_name[lineval], + ifstate_name[ifstate[depth]], depth); + } +} + +/* + * Parse a line and determine its type. We keep the preprocessor line + * parser state between calls in the global variable linestate, with + * help from skipcomment(). + */ +static Linetype +getline(void) +{ + const char *cp; + int cursym; + int kwlen; + Linetype retval; + Comment_state wascomment; + + if (fgets(tline, MAXLINE, input) == NULL) + return (LT_EOF); + retval = LT_PLAIN; + wascomment = incomment; + cp = skipcomment(tline); + if (linestate == LS_START) { + if (*cp == '#') { + linestate = LS_HASH; + cp = skipcomment(cp + 1); + } else if (*cp != '\0') + linestate = LS_DIRTY; + } + if (!incomment && linestate == LS_HASH) { + keyword = tline + (cp - tline); + cp = skipsym(cp); + kwlen = cp - keyword; + /* no way can we deal with a continuation inside a keyword */ + if (strncmp(cp, "\\\n", 2) == 0) + Eioccc(); + if (strlcmp("ifdef", keyword, kwlen) == 0 || + strlcmp("ifndef", keyword, kwlen) == 0) { + cp = skipcomment(cp); + if ((cursym = findsym(cp)) < 0) + retval = LT_IF; + else { + retval = (keyword[2] == 'n') + ? LT_FALSE : LT_TRUE; + if (value[cursym] == NULL) + retval = (retval == LT_TRUE) + ? LT_FALSE : LT_TRUE; + if (ignore[cursym]) + retval = (retval == LT_TRUE) + ? LT_TRUEI : LT_FALSEI; + } + cp = skipsym(cp); + } else if (strlcmp("if", keyword, kwlen) == 0) + retval = ifeval(&cp); + else if (strlcmp("elif", keyword, kwlen) == 0) + retval = ifeval(&cp) - LT_IF + LT_ELIF; + else if (strlcmp("else", keyword, kwlen) == 0) + retval = LT_ELSE; + else if (strlcmp("endif", keyword, kwlen) == 0) + retval = LT_ENDIF; + else { + linestate = LS_DIRTY; + retval = LT_PLAIN; + } + cp = skipcomment(cp); + if (*cp != '\0') { + linestate = LS_DIRTY; + if (retval == LT_TRUE || retval == LT_FALSE || + retval == LT_TRUEI || retval == LT_FALSEI) + retval = LT_IF; + if (retval == LT_ELTRUE || retval == LT_ELFALSE) + retval = LT_ELIF; + } + if (retval != LT_PLAIN && (wascomment || incomment)) { + retval += LT_DODGY; + if (incomment) + linestate = LS_DIRTY; + } + /* skipcomment should have changed the state */ + if (linestate == LS_HASH) + abort(); /* bug */ + } + if (linestate == LS_DIRTY) { + while (*cp != '\0') + cp = skipcomment(cp + 1); + } + debug("parser %s comment %s line", + comment_name[incomment], linestate_name[linestate]); + return (retval); +} + +/* + * These are the binary operators that are supported by the expression + * evaluator. Note that if support for division is added then we also + * need short-circuiting booleans because of divide-by-zero. + */ +static int op_lt(int a, int b) { return (a < b); } +static int op_gt(int a, int b) { return (a > b); } +static int op_le(int a, int b) { return (a <= b); } +static int op_ge(int a, int b) { return (a >= b); } +static int op_eq(int a, int b) { return (a == b); } +static int op_ne(int a, int b) { return (a != b); } +static int op_or(int a, int b) { return (a || b); } +static int op_and(int a, int b) { return (a && b); } + +/* + * An evaluation function takes three arguments, as follows: (1) a pointer to + * an element of the precedence table which lists the operators at the current + * level of precedence; (2) a pointer to an integer which will receive the + * value of the expression; and (3) a pointer to a char* that points to the + * expression to be evaluated and that is updated to the end of the expression + * when evaluation is complete. The function returns LT_FALSE if the value of + * the expression is zero, LT_TRUE if it is non-zero, or LT_IF if the + * expression could not be evaluated. + */ +struct ops; + +typedef Linetype eval_fn(const struct ops *, int *, const char **); + +static eval_fn eval_table, eval_unary; + +/* + * The precedence table. Expressions involving binary operators are evaluated + * in a table-driven way by eval_table. When it evaluates a subexpression it + * calls the inner function with its first argument pointing to the next + * element of the table. Innermost expressions have special non-table-driven + * handling. + */ +static const struct ops { + eval_fn *inner; + struct op { + const char *str; + int (*fn)(int, int); + } op[5]; +} eval_ops[] = { + { eval_table, { { "||", op_or } } }, + { eval_table, { { "&&", op_and } } }, + { eval_table, { { "==", op_eq }, + { "!=", op_ne } } }, + { eval_unary, { { "<=", op_le }, + { ">=", op_ge }, + { "<", op_lt }, + { ">", op_gt } } } +}; + +/* + * Function for evaluating the innermost parts of expressions, + * viz. !expr (expr) defined(symbol) symbol number + * We reset the keepthis flag when we find a non-constant subexpression. + */ +static Linetype +eval_unary(const struct ops *ops, int *valp, const char **cpp) +{ + const char *cp; + char *ep; + int sym; + + cp = skipcomment(*cpp); + if (*cp == '!') { + debug("eval%d !", ops - eval_ops); + cp++; + if (eval_unary(ops, valp, &cp) == LT_IF) + return (LT_IF); + *valp = !*valp; + } else if (*cp == '(') { + cp++; + debug("eval%d (", ops - eval_ops); + if (eval_table(eval_ops, valp, &cp) == LT_IF) + return (LT_IF); + cp = skipcomment(cp); + if (*cp++ != ')') + return (LT_IF); + } else if (isdigit((unsigned char)*cp)) { + debug("eval%d number", ops - eval_ops); + *valp = strtol(cp, &ep, 0); + cp = skipsym(cp); + } else if (strncmp(cp, "defined", 7) == 0 && endsym(cp[7])) { + cp = skipcomment(cp+7); + debug("eval%d defined", ops - eval_ops); + if (*cp++ != '(') + return (LT_IF); + cp = skipcomment(cp); + sym = findsym(cp); + if (sym < 0) + return (LT_IF); + *valp = (value[sym] != NULL); + cp = skipsym(cp); + cp = skipcomment(cp); + if (*cp++ != ')') + return (LT_IF); + keepthis = false; + } else if (!endsym(*cp)) { + debug("eval%d symbol", ops - eval_ops); + sym = findsym(cp); + if (sym < 0) + return (LT_IF); + if (value[sym] == NULL) + *valp = 0; + else { + *valp = strtol(value[sym], &ep, 0); + if (*ep != '\0' || ep == value[sym]) + return (LT_IF); + } + cp = skipsym(cp); + keepthis = false; + } else { + debug("eval%d bad expr", ops - eval_ops); + return (LT_IF); + } + + *cpp = cp; + debug("eval%d = %d", ops - eval_ops, *valp); + return (*valp ? LT_TRUE : LT_FALSE); +} + +/* + * Table-driven evaluation of binary operators. + */ +static Linetype +eval_table(const struct ops *ops, int *valp, const char **cpp) +{ + const struct op *op; + const char *cp; + int val; + + debug("eval%d", ops - eval_ops); + cp = *cpp; + if (ops->inner(ops+1, valp, &cp) == LT_IF) + return (LT_IF); + for (;;) { + cp = skipcomment(cp); + for (op = ops->op; op->str != NULL; op++) + if (strncmp(cp, op->str, strlen(op->str)) == 0) + break; + if (op->str == NULL) + break; + cp += strlen(op->str); + debug("eval%d %s", ops - eval_ops, op->str); + if (ops->inner(ops+1, &val, &cp) == LT_IF) + return (LT_IF); + *valp = op->fn(*valp, val); + } + + *cpp = cp; + debug("eval%d = %d", ops - eval_ops, *valp); + return (*valp ? LT_TRUE : LT_FALSE); +} + +/* + * Evaluate the expression on a #if or #elif line. If we can work out + * the result we return LT_TRUE or LT_FALSE accordingly, otherwise we + * return just a generic LT_IF. + */ +static Linetype +ifeval(const char **cpp) +{ + int ret; + int val; + + debug("eval %s", *cpp); + keepthis = killconsts ? false : true; + ret = eval_table(eval_ops, &val, cpp); + debug("eval = %d", val); + return (keepthis ? LT_IF : ret); +} + +/* + * Skip over comments, strings, and character literals and stop at the + * next character position that is not whitespace. Between calls we keep + * the comment state in the global variable incomment, and we also adjust + * the global variable linestate when we see a newline. + * XXX: doesn't cope with the buffer splitting inside a state transition. + */ +static const char * +skipcomment(const char *cp) +{ + if (text || ignoring[depth]) { + for (; isspace((unsigned char)*cp); cp++) + if (*cp == '\n') + linestate = LS_START; + return (cp); + } + while (*cp != '\0') + /* don't reset to LS_START after a line continuation */ + if (strncmp(cp, "\\\n", 2) == 0) + cp += 2; + else switch (incomment) { + case NO_COMMENT: + if (strncmp(cp, "/\\\n", 3) == 0) { + incomment = STARTING_COMMENT; + cp += 3; + } else if (strncmp(cp, "/*", 2) == 0) { + incomment = C_COMMENT; + cp += 2; + } else if (strncmp(cp, "//", 2) == 0) { + incomment = CXX_COMMENT; + cp += 2; + } else if (strncmp(cp, "\'", 1) == 0) { + incomment = CHAR_LITERAL; + linestate = LS_DIRTY; + cp += 1; + } else if (strncmp(cp, "\"", 1) == 0) { + incomment = STRING_LITERAL; + linestate = LS_DIRTY; + cp += 1; + } else if (strncmp(cp, "\n", 1) == 0) { + linestate = LS_START; + cp += 1; + } else if (strchr(" \t", *cp) != NULL) { + cp += 1; + } else + return (cp); + continue; + case CXX_COMMENT: + if (strncmp(cp, "\n", 1) == 0) { + incomment = NO_COMMENT; + linestate = LS_START; + } + cp += 1; + continue; + case CHAR_LITERAL: + case STRING_LITERAL: + if ((incomment == CHAR_LITERAL && cp[0] == '\'') || + (incomment == STRING_LITERAL && cp[0] == '\"')) { + incomment = NO_COMMENT; + cp += 1; + } else if (cp[0] == '\\') { + if (cp[1] == '\0') + cp += 1; + else + cp += 2; + } else if (strncmp(cp, "\n", 1) == 0) { + if (incomment == CHAR_LITERAL) + error("unterminated char literal"); + else + error("unterminated string literal"); + } else + cp += 1; + continue; + case C_COMMENT: + if (strncmp(cp, "*\\\n", 3) == 0) { + incomment = FINISHING_COMMENT; + cp += 3; + } else if (strncmp(cp, "*/", 2) == 0) { + incomment = NO_COMMENT; + cp += 2; + } else + cp += 1; + continue; + case STARTING_COMMENT: + if (*cp == '*') { + incomment = C_COMMENT; + cp += 1; + } else if (*cp == '/') { + incomment = CXX_COMMENT; + cp += 1; + } else { + incomment = NO_COMMENT; + linestate = LS_DIRTY; + } + continue; + case FINISHING_COMMENT: + if (*cp == '/') { + incomment = NO_COMMENT; + cp += 1; + } else + incomment = C_COMMENT; + continue; + default: + abort(); /* bug */ + } + return (cp); +} + +/* + * Skip over an identifier. + */ +static const char * +skipsym(const char *cp) +{ + while (!endsym(*cp)) + ++cp; + return (cp); +} + +/* + * Look for the symbol in the symbol table. If is is found, we return + * the symbol table index, else we return -1. + */ +static int +findsym(const char *str) +{ + const char *cp; + int symind; + + cp = skipsym(str); + if (cp == str) + return (-1); + if (symlist) { + printf("%.*s\n", (int)(cp-str), str); + /* we don't care about the value of the symbol */ + return (0); + } + for (symind = 0; symind < nsyms; ++symind) { + if (strlcmp(symname[symind], str, cp-str) == 0) { + debug("findsym %s %s", symname[symind], + value[symind] ? value[symind] : ""); + return (symind); + } + } + return (-1); +} + +/* + * Add a symbol to the symbol table. + */ +static void +addsym(bool ignorethis, bool definethis, char *sym) +{ + int symind; + char *val; + + symind = findsym(sym); + if (symind < 0) { + if (nsyms >= MAXSYMS) + errx(2, "too many symbols"); + symind = nsyms++; + } + symname[symind] = sym; + ignore[symind] = ignorethis; + val = sym + (skipsym(sym) - sym); + if (definethis) { + if (*val == '=') { + value[symind] = val+1; + *val = '\0'; + } else if (*val == '\0') + value[symind] = ""; + else + usage(); + } else { + if (*val != '\0') + usage(); + value[symind] = NULL; + } +} + +/* + * Compare s with n characters of t. + * The same as strncmp() except that it checks that s[n] == '\0'. + */ +static int +strlcmp(const char *s, const char *t, size_t n) +{ + while (n-- && *t != '\0') + if (*s != *t) + return ((unsigned char)*s - (unsigned char)*t); + else + ++s, ++t; + return ((unsigned char)*s); +} + +/* + * Diagnostics. + */ +static void +debug(const char *msg, ...) +{ + va_list ap; + + if (debugging) { + va_start(ap, msg); + vwarnx(msg, ap); + va_end(ap); + } +} + +static void +error(const char *msg) +{ + if (depth == 0) + warnx("%s: %d: %s", filename, linenum, msg); + else + warnx("%s: %d: %s (#if line %d depth %d)", + filename, linenum, msg, stifline[depth], depth); + errx(2, "output may be truncated"); +} |