freebsd-dev/usr.bin/unifdef/unifdef.c
Pedro F. Giffuni 1de7b4b805 various: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:37:16 +00:00

1665 lines
46 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2002 - 2015 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 "unifdef.h"
static const char copyright[] =
"@(#) $Version: unifdef-2.11 $\n"
"@(#) $FreeBSD$\n"
"@(#) $Author: Tony Finch (dot@dotat.at) $\n"
"@(#) $URL: https://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"
};
#define linetype_if2elif(lt) ((Linetype)(lt - LT_IF + LT_ELIF))
#define linetype_2dodgy(lt) ((Linetype)(lt + LT_DODGY))
/* 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 16384 /* 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 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 inplace; /* -m: modify in place */
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 const char *linefile; /* file name for #line */
static FILE *output; /* output file pointer */
static const char *ofilename; /* output file name */
static const char *backext; /* backup extension */
static char *tempname; /* avoid splatting input */
static char tline[MAXLINE+EDITSLOP];/* input buffer plus space */
static char *keyword; /* used for editing #elif's */
/*
* When processing a file, the output's newline style will match the
* input's, and unifdef correctly handles CRLF or LF endings whatever
* the platform's native style. The stdio streams are opened in binary
* mode to accommodate platforms whose native newline style is CRLF.
* When the output isn't a processed input file (when it is error /
* debug / diagnostic messages) then unifdef uses native line endings.
*/
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; /* to format symdepth output */
static bool firstsym; /* ditto */
static int exitmode; /* exit status mode */
static int exitstat; /* program exit status */
static bool altered; /* was this file modified? */
static void addsym1(bool, bool, char *);
static void addsym2(bool, const char *, const char *);
static char *astrcat(const char *, const char *);
static void cleantemp(void);
static void closeio(void);
static void debug(const char *, ...);
static void debugsym(const char *, int);
static bool defundef(void);
static void defundefile(const char *);
static void done(void);
static void error(const char *);
static int findsym(const char **);
static void flushline(bool);
static void hashline(void);
static void help(void);
static Linetype ifeval(const char **);
static void ignoreoff(void);
static void ignoreon(void);
static void indirectsym(void);
static void keywordedit(const char *);
static const char *matchsym(const char *, const char *);
static void nest(void);
static Linetype parseline(void);
static void process(void);
static void processinout(const char *, const char *);
static const char *skipargs(const char *);
static const char *skipcomment(const char *);
static const char *skiphash(void);
static const char *skipline(const char *);
static const char *skipsym(const char *);
static void state(Ifstate);
static void unnest(void);
static void usage(void);
static void version(void);
static const char *xstrdup(const char *, const char *);
#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:f:I:M:o:x:bBcdehKklmnsStV")) != -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')
addsym1(true, true, optarg);
else if (opt == 'U')
addsym1(true, false, optarg);
else
usage();
break;
case 'D': /* define a symbol */
addsym1(false, true, optarg);
break;
case 'U': /* undef a symbol */
addsym1(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 'f': /* definitions file */
defundefile(optarg);
break;
case 'h':
help();
break;
case 'K': /* keep ambiguous #ifs */
strictlogic = true;
break;
case 'k': /* process constant #ifs */
killconsts = true;
break;
case 'm': /* modify in place */
inplace = true;
break;
case 'M': /* modify in place and keep backup */
inplace = true;
if (strlen(optarg) > 0)
backext = optarg;
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':
version();
break;
case 'x':
exitmode = atoi(optarg);
if(exitmode < 0 || exitmode > 2)
usage();
break;
default:
usage();
}
argc -= optind;
argv += optind;
if (compblank && lnblank)
errx(2, "-B and -b are mutually exclusive");
if (symlist && (ofilename != NULL || inplace || argc > 1))
errx(2, "-s only works with one input file");
if (argc > 1 && ofilename != NULL)
errx(2, "-o cannot be used with multiple input files");
if (argc > 1 && !inplace)
errx(2, "multiple input files require -m or -M");
if (argc == 0 && inplace)
errx(2, "-m requires an input file");
if (argc == 0)
argc = 1;
if (argc == 1 && !inplace && ofilename == NULL)
ofilename = "-";
indirectsym();
atexit(cleantemp);
if (ofilename != NULL)
processinout(*argv, ofilename);
else while (argc-- > 0) {
processinout(*argv, *argv);
argv++;
}
switch(exitmode) {
case(0): exit(exitstat);
case(1): exit(!exitstat);
case(2): exit(0);
default: abort(); /* bug */
}
}
/*
* File logistics.
*/
static void
processinout(const char *ifn, const char *ofn)
{
struct stat st;
if (ifn == NULL || strcmp(ifn, "-") == 0) {
filename = "[stdin]";
linefile = NULL;
input = fbinmode(stdin);
} else {
filename = ifn;
linefile = ifn;
input = fopen(ifn, "rb");
if (input == NULL)
err(2, "can't open %s", ifn);
}
if (strcmp(ofn, "-") == 0) {
output = fbinmode(stdout);
process();
return;
}
if (stat(ofn, &st) < 0) {
output = fopen(ofn, "wb");
if (output == NULL)
err(2, "can't create %s", ofn);
process();
return;
}
tempname = astrcat(ofn, ".XXXXXX");
output = mktempmode(tempname, st.st_mode);
if (output == NULL)
err(2, "can't create %s", tempname);
process();
if (backext != NULL) {
char *backname = astrcat(ofn, backext);
if (rename(ofn, backname) < 0)
err(2, "can't rename \"%s\" to \"%s\"", ofn, backname);
free(backname);
}
/* leave file unmodified if unifdef made no changes */
if (!altered && backext == NULL) {
if (remove(tempname) < 0)
warn("can't remove \"%s\"", tempname);
} else if (replace(tempname, ofn) < 0)
err(2, "can't rename \"%s\" to \"%s\"", tempname, ofn);
free(tempname);
tempname = NULL;
}
/*
* For cleaning up if there is an error.
*/
static void
cleantemp(void)
{
if (tempname != NULL)
remove(tempname);
}
/*
* Self-identification functions.
*/
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
synopsis(FILE *fp)
{
fprintf(fp,
"usage: unifdef [-bBcdehKkmnsStV] [-x{012}] [-Mext] [-opath] \\\n"
" [-[i]Dsym[=val]] [-[i]Usym] [-fpath] ... [file] ...\n");
}
static void
usage(void)
{
synopsis(stderr);
exit(2);
}
static void
help(void)
{
synopsis(stdout);
printf(
" -Dsym=val define preprocessor symbol with given value\n"
" -Dsym define preprocessor symbol with value 1\n"
" -Usym preprocessor symbol is undefined\n"
" -iDsym=val \\ ignore C strings and comments\n"
" -iDsym ) in sections controlled by these\n"
" -iUsym / preprocessor symbols\n"
" -fpath file containing #define and #undef directives\n"
" -b blank lines instead of deleting them\n"
" -B compress blank lines around deleted section\n"
" -c complement (invert) keep vs. delete\n"
" -d debugging mode\n"
" -e ignore multiline preprocessor directives\n"
" -h print help\n"
" -Ipath extra include file path (ignored)\n"
" -K disable && and || short-circuiting\n"
" -k process constant #if expressions\n"
" -Mext modify in place and keep backups\n"
" -m modify input files in place\n"
" -n add #line directives to output\n"
" -opath output file name\n"
" -S list #if control symbols with nesting\n"
" -s list #if control symbols\n"
" -t ignore C strings and comments\n"
" -V print version\n"
" -x{012} exit status mode\n"
);
exit(0);
}
/*
* 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);
altered = true;
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;
}
/*
* The last state transition function. When this is called,
* lineval == LT_EOF, so the process() loop will terminate.
*/
static void
done(void)
{
if (incomment)
error("EOF in comment");
closeio();
}
/*
* Write a line to the output or not, according to command line options.
* If writing fails, closeio() will print the error and exit.
*/
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)
hashline();
if (fputs(tline, output) == EOF)
closeio();
delcount = 0;
blankmax = blankcount = blankline ? blankcount + 1 : 0;
}
} else {
if (lnblank && fputs(newline, output) == EOF)
closeio();
altered = true;
delcount += 1;
blankcount = 0;
}
if (debugging && fflush(output) == EOF)
closeio();
}
/*
* Format of #line directives depends on whether we know the input filename.
*/
static void
hashline(void)
{
int e;
if (linefile == NULL)
e = fprintf(output, "#line %d%s", linenum, newline);
else
e = fprintf(output, "#line %d \"%s\"%s",
linenum, linefile, newline);
if (e < 0)
closeio();
}
/*
* Flush the output and handle errors.
*/
static void
closeio(void)
{
/* Tidy up after findsym(). */
if (symdepth && !zerosyms)
printf("\n");
if (output != NULL && (ferror(output) || fclose(output) == EOF))
err(2, "%s: can't write to output", filename);
fclose(input);
}
/*
* The driver for the state machine.
*/
static void
process(void)
{
Linetype lineval = LT_PLAIN;
/* When compressing blank lines, act as if the file
is preceded by a large number of blank lines. */
blankmax = blankcount = 1000;
zerosyms = true;
newline = NULL;
linenum = 0;
altered = false;
while (lineval != LT_EOF) {
lineval = parseline();
trans_table[ifstate[depth]][lineval]();
debug("process line %d %s -> %s depth %d",
linenum, linetype_name[lineval],
ifstate_name[ifstate[depth]], depth);
}
exitstat |= altered;
}
/*
* 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;
Linetype retval;
Comment_state wascomment;
wascomment = incomment;
cp = skiphash();
if (cp == NULL)
return (LT_EOF);
if (newline == NULL) {
if (strrchr(tline, '\n') == strrchr(tline, '\r') + 1)
newline = newline_crlf;
else
newline = newline_unix;
}
if (*cp == '\0') {
retval = LT_PLAIN;
goto done;
}
keyword = tline + (cp - tline);
if ((cp = matchsym("ifdef", keyword)) != NULL ||
(cp = matchsym("ifndef", keyword)) != NULL) {
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;
}
} else if ((cp = matchsym("if", keyword)) != NULL)
retval = ifeval(&cp);
else if ((cp = matchsym("elif", keyword)) != NULL)
retval = linetype_if2elif(ifeval(&cp));
else if ((cp = matchsym("else", keyword)) != NULL)
retval = LT_ELSE;
else if ((cp = matchsym("endif", keyword)) != NULL)
retval = LT_ENDIF;
else {
cp = skipsym(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();
cp = skipline(cp);
retval = LT_PLAIN;
goto done;
}
cp = skipcomment(cp);
if (*cp != '\0') {
cp = skipline(cp);
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;
}
/* the following can happen if the last line of the file lacks a
newline or if there is too much whitespace in a directive */
if (linestate == LS_HASH) {
long len = cp - tline;
if (fgets(tline + len, MAXLINE - len, input) == NULL) {
if (ferror(input))
err(2, "can't read %s", filename);
/* append the missing newline at eof */
strcpy(tline + len, newline);
cp += strlen(newline);
linestate = LS_START;
} else {
linestate = LS_DIRTY;
}
}
if (retval != LT_PLAIN && (wascomment || linestate != LS_START)) {
retval = linetype_2dodgy(retval);
linestate = LS_DIRTY;
}
done:
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(long *p, long 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(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a < b, at, bt);
}
static Linetype op_gt(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a > b, at, bt);
}
static Linetype op_le(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a <= b, at, bt);
}
static Linetype op_ge(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a >= b, at, bt);
}
static Linetype op_eq(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a == b, at, bt);
}
static Linetype op_ne(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a != b, at, bt);
}
static Linetype op_or(long *p, Linetype at, long a, Linetype bt, long 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(long *p, Linetype at, long a, Linetype bt, long b) {
if (!strictlogic && (at == LT_FALSE || bt == LT_FALSE))
return (*p = 0, LT_FALSE);
return op_strict(p, a && b, at, bt);
}
static Linetype op_blsh(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a << b, at, bt);
}
static Linetype op_brsh(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a >> b, at, bt);
}
static Linetype op_add(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a + b, at, bt);
}
static Linetype op_sub(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a - b, at, bt);
}
static Linetype op_mul(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a * b, at, bt);
}
static Linetype op_div(long *p, Linetype at, long a, Linetype bt, long b) {
if (bt != LT_TRUE) {
debug("eval division by zero");
return (LT_ERROR);
}
return op_strict(p, a / b, at, bt);
}
static Linetype op_mod(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a % b, at, bt);
}
static Linetype op_bor(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a | b, at, bt);
}
static Linetype op_bxor(long *p, Linetype at, long a, Linetype bt, long b) {
return op_strict(p, a ^ b, at, bt);
}
static Linetype op_band(long *p, Linetype at, long a, Linetype bt, long b) {
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 *, long *, 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.
*
* The stop characters help with lexical analysis: an operator is not
* recognized if it is followed by one of the stop characters because
* that would make it a different operator.
*/
struct op {
const char *str;
Linetype (*fn)(long *, Linetype, long, Linetype, long);
const char *stop;
};
struct ops {
eval_fn *inner;
struct op op[5];
};
static const struct ops eval_ops[] = {
{ eval_table, { { "||", op_or, NULL } } },
{ eval_table, { { "&&", op_and, NULL } } },
{ eval_table, { { "|", op_bor, "|" } } },
{ eval_table, { { "^", op_bxor, NULL } } },
{ eval_table, { { "&", op_band, "&" } } },
{ eval_table, { { "==", op_eq, NULL },
{ "!=", op_ne, NULL } } },
{ eval_table, { { "<=", op_le, NULL },
{ ">=", op_ge, NULL },
{ "<", op_lt, "<=" },
{ ">", op_gt, ">=" } } },
{ eval_table, { { "<<", op_blsh, NULL },
{ ">>", op_brsh, NULL } } },
{ eval_table, { { "+", op_add, NULL },
{ "-", op_sub, NULL } } },
{ eval_unary, { { "*", op_mul, NULL },
{ "/", op_div, NULL },
{ "%", op_mod, NULL } } },
};
/* Current operator precedence level */
static long prec(const struct ops *ops)
{
return (ops - eval_ops);
}
/*
* 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, long *valp, const char **cpp)
{
const char *cp;
char *ep;
int sym;
bool defparen;
Linetype lt;
cp = skipcomment(*cpp);
if (*cp == '!') {
debug("eval%d !", prec(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 == '~') {
debug("eval%d ~", prec(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 == '-') {
debug("eval%d -", prec(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 (", prec(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", prec(ops));
*valp = strtol(cp, &ep, 0);
if (ep == cp)
return (LT_ERROR);
lt = *valp ? LT_TRUE : LT_FALSE;
cp = ep;
} else if (matchsym("defined", cp) != NULL) {
cp = skipcomment(cp+7);
if (*cp == '(') {
cp = skipcomment(cp+1);
defparen = true;
} else {
defparen = false;
}
sym = findsym(&cp);
cp = skipcomment(cp);
if (defparen && *cp++ != ')') {
debug("eval%d defined missing ')'", prec(ops));
return (LT_ERROR);
}
if (sym < 0) {
debug("eval%d defined unknown", prec(ops));
lt = LT_IF;
} else {
debug("eval%d defined %s", prec(ops), symname[sym]);
*valp = (value[sym] != NULL);
lt = *valp ? LT_TRUE : LT_FALSE;
}
constexpr = false;
} else if (!endsym(*cp)) {
debug("eval%d symbol", prec(ops));
sym = findsym(&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", prec(ops));
return (LT_ERROR);
}
*cpp = cp;
debug("eval%d = %d", prec(ops), *valp);
return (lt);
}
/*
* Table-driven evaluation of binary operators.
*/
static Linetype
eval_table(const struct ops *ops, long *valp, const char **cpp)
{
const struct op *op;
const char *cp;
long val = 0;
Linetype lt, rt;
debug("eval%d", prec(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) {
/* assume only one-char operators have stop chars */
if (op->stop != NULL && cp[1] != '\0' &&
strchr(op->stop, cp[1]) != NULL)
continue;
else
break;
}
}
if (op->str == NULL)
break;
cp += strlen(op->str);
debug("eval%d %s", prec(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", prec(ops), *valp);
debug("eval%d lt = %s", prec(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)
{
Linetype ret;
long 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);
}
/*
* Read a line and examine its initial part to determine if it is a
* preprocessor directive. Returns NULL on EOF, or a pointer to a
* preprocessor directive name, or a pointer to the zero byte at the
* end of the line.
*/
static const char *
skiphash(void)
{
const char *cp;
linenum++;
if (fgets(tline, MAXLINE, input) == NULL) {
if (ferror(input))
err(2, "can't read %s", filename);
else
return (NULL);
}
cp = skipcomment(tline);
if (linestate == LS_START && *cp == '#') {
linestate = LS_HASH;
return (skipcomment(cp + 1));
} else if (*cp == '\0') {
return (cp);
} else {
return (skipline(cp));
}
}
/*
* Mark a line dirty and consume the rest of it, keeping track of the
* lexical state.
*/
static const char *
skipline(const char *cp)
{
const char *pcp;
if (*cp != '\0')
linestate = LS_DIRTY;
while (*cp != '\0') {
cp = skipcomment(pcp = cp);
if (pcp == cp)
cp++;
}
return (cp);
}
/*
* 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);
}
/*
* Skip whitespace and take a copy of any following identifier.
*/
static const char *
getsym(const char **cpp)
{
const char *cp = *cpp, *sym;
cp = skipcomment(cp);
cp = skipsym(sym = cp);
if (cp == sym)
return NULL;
*cpp = cp;
return (xstrdup(sym, cp));
}
/*
* Check that s (a symbol) matches the start of t, and that the
* following character in t is not a symbol character. Returns a
* pointer to the following character in t if there is a match,
* otherwise NULL.
*/
static const char *
matchsym(const char *s, const char *t)
{
while (*s != '\0' && *t != '\0')
if (*s != *t)
return (NULL);
else
++s, ++t;
if (*s == '\0' && endsym(*t))
return(t);
else
return(NULL);
}
/*
* 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 **strp)
{
const char *str;
int symind;
str = *strp;
*strp = skipsym(str);
if (symlist) {
if (*strp == str)
return (-1);
if (symdepth && firstsym)
printf("%s%3d", zerosyms ? "" : "\n", depth);
firstsym = zerosyms = false;
printf("%s%.*s%s",
symdepth ? " " : "",
(int)(*strp-str), str,
symdepth ? "" : "\n");
/* we don't care about the value of the symbol */
return (0);
}
for (symind = 0; symind < nsyms; ++symind) {
if (matchsym(symname[symind], str) != NULL) {
debugsym("findsym", symind);
return (symind);
}
}
return (-1);
}
/*
* Resolve indirect symbol values to their final definitions.
*/
static void
indirectsym(void)
{
const char *cp;
int changed, sym, ind;
do {
changed = 0;
for (sym = 0; sym < nsyms; ++sym) {
if (value[sym] == NULL)
continue;
cp = value[sym];
ind = findsym(&cp);
if (ind == -1 || ind == sym ||
*cp != '\0' ||
value[ind] == NULL ||
value[ind] == value[sym])
continue;
debugsym("indir...", sym);
value[sym] = value[ind];
debugsym("...ectsym", sym);
changed++;
}
} while (changed);
}
/*
* Add a symbol to the symbol table, specified with the format sym=val
*/
static void
addsym1(bool ignorethis, bool definethis, char *symval)
{
const char *sym, *val;
sym = symval;
val = skipsym(sym);
if (definethis && *val == '=') {
symval[val - sym] = '\0';
val = val + 1;
} else if (*val == '\0') {
val = definethis ? "1" : NULL;
} else {
usage();
}
addsym2(ignorethis, sym, val);
}
/*
* Add a symbol to the symbol table.
*/
static void
addsym2(bool ignorethis, const char *sym, const char *val)
{
const char *cp = sym;
int symind;
symind = findsym(&cp);
if (symind < 0) {
if (nsyms >= MAXSYMS)
errx(2, "too many symbols");
symind = nsyms++;
}
ignore[symind] = ignorethis;
symname[symind] = sym;
value[symind] = val;
debugsym("addsym", symind);
}
static void
debugsym(const char *why, int symind)
{
debug("%s %s%c%s", why, symname[symind],
value[symind] ? '=' : ' ',
value[symind] ? value[symind] : "undef");
}
/*
* Add symbols to the symbol table from a file containing
* #define and #undef preprocessor directives.
*/
static void
defundefile(const char *fn)
{
filename = fn;
input = fopen(fn, "rb");
if (input == NULL)
err(2, "can't open %s", fn);
linenum = 0;
while (defundef())
;
if (ferror(input))
err(2, "can't read %s", filename);
else
fclose(input);
if (incomment)
error("EOF in comment");
}
/*
* Read and process one #define or #undef directive
*/
static bool
defundef(void)
{
const char *cp, *kw, *sym, *val, *end;
cp = skiphash();
if (cp == NULL)
return (false);
if (*cp == '\0')
goto done;
/* strip trailing whitespace, and do a fairly rough check to
avoid unsupported multi-line preprocessor directives */
end = cp + strlen(cp);
while (end > tline && strchr(" \t\n\r", end[-1]) != NULL)
--end;
if (end > tline && end[-1] == '\\')
Eioccc();
kw = cp;
if ((cp = matchsym("define", kw)) != NULL) {
sym = getsym(&cp);
if (sym == NULL)
error("Missing macro name in #define");
if (*cp == '(') {
val = "1";
} else {
cp = skipcomment(cp);
val = (cp < end) ? xstrdup(cp, end) : "";
}
debug("#define");
addsym2(false, sym, val);
} else if ((cp = matchsym("undef", kw)) != NULL) {
sym = getsym(&cp);
if (sym == NULL)
error("Missing macro name in #undef");
cp = skipcomment(cp);
debug("#undef");
addsym2(false, sym, NULL);
} else {
error("Unrecognized preprocessor directive");
}
skipline(cp);
done:
debug("parser line %d state %s comment %s line", linenum,
comment_name[incomment], linestate_name[linestate]);
return (true);
}
/*
* Concatenate two strings into new memory, checking for failure.
*/
static char *
astrcat(const char *s1, const char *s2)
{
char *s;
int len;
size_t size;
len = snprintf(NULL, 0, "%s%s", s1, s2);
if (len < 0)
err(2, "snprintf");
size = (size_t)len + 1;
s = (char *)malloc(size);
if (s == NULL)
err(2, "malloc");
snprintf(s, size, "%s%s", s1, s2);
return (s);
}
/*
* Duplicate a segment of a string, checking for failure.
*/
static const char *
xstrdup(const char *start, const char *end)
{
size_t n;
char *s;
if (end < start) abort(); /* bug */
n = (size_t)(end - start) + 1;
s = malloc(n);
if (s == NULL)
err(2, "malloc");
snprintf(s, n, "%s", start);
return (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);
closeio();
errx(2, "Output may be truncated");
}