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unifdef.c
/* * Copyright (c) 2002 - 2011 Tony Finch <dot@dotat.at> * * 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. */ /* * unifdef - remove ifdef'ed lines * * This code was 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 4-clause BSD copyright licence. None of its code * remains in this version (though some of the names remain) so it now * carries a more liberal licence. * * 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 * * These require better buffer handling, which would also make * it possible to handle all "dodgy" directives correctly. */ #include <sys/types.h> #include <sys/stat.h> #include <ctype.h> #include <err.h> #include <errno.h> #include <stdarg.h> #include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> const char copyright[] = "@(#) $Version: unifdef-2.5 $\n" "@(#) $Author: Tony Finch (dot@dotat.at) $\n" "@(#) $URL: http://dotat.at/prog/unifdef $\n" ; /* 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_ERROR, /* unevaluable #if */ 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", "ERROR" }; /* 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 /* * For temporary filenames */ #define TEMPLATE "unifdef.XXXXXX" /* * Globals. */ static bool compblank; /* -B: compress blank lines */ static bool lnblank; /* -b: blank deleted lines */ static bool complement; /* -c: do the complement */ static bool debugging; /* -d: debugging reports */ static bool iocccok; /* -e: fewer IOCCC errors */ static bool strictlogic; /* -K: keep ambiguous #ifs */ static bool killconsts; /* -k: eval constant #ifs */ static bool lnnum; /* -n: add #line directives */ static bool symlist; /* -s: output symbol list */ static bool symdepth; /* -S: output symbol depth */ 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 FILE *output; /* output file pointer */ static const char *ofilename; /* output file name */ static bool overwriting; /* output overwrites input */ static char tempname[FILENAME_MAX]; /* used when overwriting */ static char tline[MAXLINE+EDITSLOP];/* input buffer plus space */ static char *keyword; /* used for editing #elif's */ static const char *newline; /* input file format */ static const char newline_unix[] = "\n"; static const char newline_crlf[] = "\r\n"; 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 unsigned blankcount; /* count of blank lines */ static unsigned blankmax; /* maximum recent blankcount */ static bool constexpr; /* constant #if expression */ static bool zerosyms = true; /* to format symdepth output */ static bool firstsym; /* ditto */ static int exitstat; /* program exit status */ static void addsym(bool, bool, char *); static void closeout(void); 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 parseline(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 *skipargs(const char *); 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); static void version(void); #define endsym(c) (!isalnum((unsigned char)c) && c != '_') /* * The main program. */ int main(int argc, char *argv[]) { int opt; while ((opt = getopt(argc, argv, "i:D:U:I:o:bBcdeKklnsStV")) != -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 'b': /* blank deleted lines instead of omitting them */ case 'l': /* backwards compatibility */ lnblank = true; break; case 'B': /* compress blank lines around removed section */ compblank = true; 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': /* keep ambiguous #ifs */ strictlogic = true; break; case 'k': /* process constant #ifs */ killconsts = true; break; case 'n': /* add #line directive after deleted lines */ lnnum = true; break; case 'o': /* output to a file */ ofilename = optarg; break; case 's': /* only output list of symbols that control #ifs */ symlist = true; break; case 'S': /* list symbols with their nesting depth */ symlist = symdepth = true; break; case 't': /* don't parse C comments */ text = true; break; case 'V': /* print version */ version(); default: usage(); } argc -= optind; argv += optind; if (compblank && lnblank) errx(2, "-B and -b are mutually exclusive"); if (argc > 1) { errx(2, "can only do one file"); } else if (argc == 1 && strcmp(*argv, "-") != 0) { filename = *argv; input = fopen(filename, "rb"); if (input == NULL) err(2, "can't open %s", filename); } else { filename = "[stdin]"; input = stdin; } if (ofilename == NULL) { ofilename = "[stdout]"; output = stdout; } else { struct stat ist, ost; if (stat(ofilename, &ost) == 0 && fstat(fileno(input), &ist) == 0) overwriting = (ist.st_dev == ost.st_dev && ist.st_ino == ost.st_ino); if (overwriting) { const char *dirsep; int ofd; dirsep = strrchr(ofilename, '/'); if (dirsep != NULL) snprintf(tempname, sizeof(tempname), "%.*s/" TEMPLATE, (int)(dirsep - ofilename), ofilename); else snprintf(tempname, sizeof(tempname), TEMPLATE); ofd = mkstemp(tempname); if (ofd != -1) output = fdopen(ofd, "wb+"); if (output == NULL) err(2, "can't create temporary file"); fchmod(ofd, ist.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)); } else { output = fopen(ofilename, "wb"); if (output == NULL) err(2, "can't open %s", ofilename); } } process(); abort(); /* bug */ } static void version(void) { const char *c = copyright; for (;;) { while (*++c != '$') if (*c == '\0') exit(0); while (*++c != '$') putc(*c, stderr); putc('\n', stderr); } } static void usage(void) { fprintf(stderr, "usage: unifdef [-bBcdeKknsStV] [-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. We use memcpy() to * overwrite the 4 byte token "elif" with "if " without a '\0' byte. * * 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(); } /* modify this line */ static void Mpass (void) { memcpy(keyword, "if ", 4); Pelif(); } static void Mtrue (void) { keywordedit("else"); state(IS_TRUE_MIDDLE); } static void Melif (void) { keywordedit("endif"); state(IS_FALSE_TRAILER); } static void Melse (void) { keywordedit("endif"); 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, abort }, /* 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, abort }, /* 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, abort }, /* 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, abort }, /* 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, abort }, /* 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, abort }, /* 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, abort }, /* 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, abort }, /* 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, abort }, /* 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, abort } /*TRUEI FALSEI IF TRUE FALSE ELIF ELTRUE ELFALSE ELSE ENDIF TRUEI FALSEI IF TRUE FALSE ELIF ELTRUE ELFALSE ELSE ENDIF (DODGY) PLAIN EOF ERROR */ }; /* * State machine utility functions */ 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) { snprintf(keyword, tline + sizeof(tline) - keyword, "%s%s", replacement, newline); print(); } static void nest(void) { if (depth > MAXDEPTH-1) abort(); /* bug */ if (depth == MAXDEPTH-1) error("Too many levels of nesting"); depth += 1; 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) { bool blankline = tline[strspn(tline, " \t\r\n")] == '\0'; if (blankline && compblank && blankcount != blankmax) { delcount += 1; blankcount += 1; } else { if (lnnum && delcount > 0) printf("#line %d%s", linenum, newline); fputs(tline, output); delcount = 0; blankmax = blankcount = blankline ? blankcount + 1 : 0; } } else { if (lnblank) fputs(newline, output); exitstat = 1; delcount += 1; blankcount = 0; } if (debugging) fflush(output); } /* * The driver for the state machine. */ static void process(void) { /* When compressing blank lines, act as if the file is preceded by a large number of blank lines. */ blankmax = blankcount = 1000; for (;;) { Linetype lineval = parseline(); trans_table[ifstate[depth]][lineval](); debug("process line %d %s -> %s depth %d", linenum, linetype_name[lineval], ifstate_name[ifstate[depth]], depth); } } /* * Flush the output and handle errors. */ static void closeout(void) { if (symdepth && !zerosyms) printf("\n"); if (fclose(output) == EOF) { warn("couldn't write to %s", ofilename); if (overwriting) { unlink(tempname); errx(2, "%s unchanged", filename); } else { exit(2); } } } /* * Clean up and exit. */ static void done(void) { if (incomment) error("EOF in comment"); closeout(); if (overwriting && rename(tempname, ofilename) == -1) { warn("couldn't rename temporary file"); unlink(tempname); errx(2, "%s unchanged", ofilename); } exit(exitstat); } /* * 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 parseline(void) { const char *cp; int cursym; int kwlen; Linetype retval; Comment_state wascomment; linenum++; if (fgets(tline, MAXLINE, input) == NULL) return (LT_EOF); if (newline == NULL) { if (strrchr(tline, '\n') == strrchr(tline, '\r') + 1) newline = newline_crlf; else newline = newline_unix; } retval = LT_PLAIN; wascomment = incomment; cp = skipcomment(tline); if (linestate == LS_START) { if (*cp == '#') { linestate = LS_HASH; firstsym = true; 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, "\\\r\n", 3) == 0 || 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 normally changes the state, except if the last line of the file lacks a newline, or if there is too much whitespace in a directive */ if (linestate == LS_HASH) { size_t len = cp - tline; if (fgets(tline + len, MAXLINE - len, input) == NULL) { /* append the missing newline */ strcpy(tline + len, newline); cp += strlen(newline); linestate = LS_START; } else { linestate = LS_DIRTY; } } } if (linestate == LS_DIRTY) { while (*cp != '\0') cp = skipcomment(cp + 1); } debug("parser line %d state %s comment %s line", linenum, comment_name[incomment], linestate_name[linestate]); return (retval); } /* * These are the binary operators that are supported by the expression * evaluator. */ static Linetype op_strict(int *p, int v, Linetype at, Linetype bt) { if(at == LT_IF || bt == LT_IF) return (LT_IF); return (*p = v, v ? LT_TRUE : LT_FALSE); } static Linetype op_lt(int *p, Linetype at, int a, Linetype bt, int b) { return op_strict(p, a < b, at, bt); } static Linetype op_gt(int *p, Linetype at, int a, Linetype bt, int b) { return op_strict(p, a > b, at, bt); } static Linetype op_le(int *p, Linetype at, int a, Linetype bt, int b) { return op_strict(p, a <= b, at, bt); } static Linetype op_ge(int *p, Linetype at, int a, Linetype bt, int b) { return op_strict(p, a >= b, at, bt); } static Linetype op_eq(int *p, Linetype at, int a, Linetype bt, int b) { return op_strict(p, a == b, at, bt); } static Linetype op_ne(int *p, Linetype at, int a, Linetype bt, int b) { return op_strict(p, a != b, at, bt); } static Linetype op_or(int *p, Linetype at, int a, Linetype bt, int b) { if (!strictlogic && (at == LT_TRUE || bt == LT_TRUE)) return (*p = 1, LT_TRUE); return op_strict(p, a || b, at, bt); } static Linetype op_and(int *p, Linetype at, int a, Linetype bt, int b) { if (!strictlogic && (at == LT_FALSE || bt == LT_FALSE)) return (*p = 0, LT_FALSE); return op_strict(p, a && b, at, bt); } /* * 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, LT_IF if the expression * depends on an unknown symbol, or LT_ERROR if there is a parse failure. */ 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; Linetype (*fn)(int *, Linetype, int, Linetype, 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) number defined(symbol) symbol * We reset the constexpr flag in the last two cases. */ static Linetype eval_unary(const struct ops *ops, int *valp, const char **cpp) { const char *cp; char *ep; int sym; bool defparen; Linetype lt; cp = skipcomment(*cpp); if (*cp == '!') { debug("eval%d !", ops - eval_ops); cp++; lt = eval_unary(ops, valp, &cp); if (lt == LT_ERROR) return (LT_ERROR); if (lt != LT_IF) { *valp = !*valp; lt = *valp ? LT_TRUE : LT_FALSE; } } else if (*cp == '(') { cp++; debug("eval%d (", ops - eval_ops); lt = eval_table(eval_ops, valp, &cp); if (lt == LT_ERROR) return (LT_ERROR); cp = skipcomment(cp); if (*cp++ != ')') return (LT_ERROR); } else if (isdigit((unsigned char)*cp)) { debug("eval%d number", ops - eval_ops); *valp = strtol(cp, &ep, 0); if (ep == cp) return (LT_ERROR); lt = *valp ? LT_TRUE : LT_FALSE; 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 == '(') { cp = skipcomment(cp+1); defparen = true; } else { defparen = false; } sym = findsym(cp); if (sym < 0) { lt = LT_IF; } else { *valp = (value[sym] != NULL); lt = *valp ? LT_TRUE : LT_FALSE; } cp = skipsym(cp); cp = skipcomment(cp); if (defparen && *cp++ != ')') return (LT_ERROR); constexpr = false; } else if (!endsym(*cp)) { debug("eval%d symbol", ops - eval_ops); sym = findsym(cp); cp = skipsym(cp); if (sym < 0) { lt = LT_IF; cp = skipargs(cp); } else if (value[sym] == NULL) { *valp = 0; lt = LT_FALSE; } else { *valp = strtol(value[sym], &ep, 0); if (*ep != '\0' || ep == value[sym]) return (LT_ERROR); lt = *valp ? LT_TRUE : LT_FALSE; cp = skipargs(cp); } constexpr = false; } else { debug("eval%d bad expr", ops - eval_ops); return (LT_ERROR); } *cpp = cp; debug("eval%d = %d", ops - eval_ops, *valp); return (lt); } /* * 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; Linetype lt, rt; debug("eval%d", ops - eval_ops); cp = *cpp; lt = ops->inner(ops+1, valp, &cp); if (lt == LT_ERROR) return (LT_ERROR); 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); rt = ops->inner(ops+1, &val, &cp); if (rt == LT_ERROR) return (LT_ERROR); lt = op->fn(valp, lt, *valp, rt, val); } *cpp = cp; debug("eval%d = %d", ops - eval_ops, *valp); debug("eval%d lt = %s", ops - eval_ops, linetype_name[lt]); return (lt); } /* * 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 = 0; debug("eval %s", *cpp); constexpr = killconsts ? false : true; ret = eval_table(eval_ops, &val, cpp); debug("eval = %d", val); return (constexpr ? LT_IF : ret == LT_ERROR ? 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, "\\\r\n", 3) == 0) cp += 3; else if (strncmp(cp, "\\\n", 2) == 0) cp += 2; else switch (incomment) { case NO_COMMENT: if (strncmp(cp, "/\\\r\n", 4) == 0) { incomment = STARTING_COMMENT; cp += 4; } else 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(" \r\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, "*\\\r\n", 4) == 0) { incomment = FINISHING_COMMENT; cp += 4; } else 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 macro arguments. */ static const char * skipargs(const char *cp) { const char *ocp = cp; int level = 0; cp = skipcomment(cp); if (*cp != '(') return (cp); do { if (*cp == '(') level++; if (*cp == ')') level--; cp = skipcomment(cp+1); } while (level != 0 && *cp != '\0'); if (level == 0) return (cp); else /* Rewind and re-detect the syntax error later. */ return (ocp); } /* * 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 it 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) { if (symdepth && firstsym) printf("%s%3d", zerosyms ? "" : "\n", depth); firstsym = zerosyms = false; printf("%s%.*s%s", symdepth ? " " : "", (int)(cp-str), str, symdepth ? "" : "\n"); /* 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] = "1"; else usage(); } else { if (*val != '\0') usage(); value[symind] = NULL; } debug("addsym %s=%s", symname[symind], value[symind] ? value[symind] : "undef"); } /* * 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); closeout(); errx(2, "output may be truncated"); }
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