/*
* 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[] =
#include "version.h"
"@(#) $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"
};
#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 } } },
{ eval_table, { { "&&", op_and } } },
{ eval_table, { { "|", op_bor, "|" } } },
{ eval_table, { { "^", op_bxor } } },
{ eval_table, { { "&", op_band, "&" } } },
{ eval_table, { { "==", op_eq },
{ "!=", op_ne } } },
{ eval_table, { { "<=", op_le },
{ ">=", op_ge },
{ "<", op_lt, "<=" },
{ ">", op_gt, ">=" } } },
{ eval_table, { { "<<", op_blsh },
{ ">>", op_brsh } } },
{ eval_table, { { "+", op_add },
{ "-", op_sub } } },
{ eval_unary, { { "*", op_mul },
{ "/", op_div },
{ "%", op_mod } } },
};
/* 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");
}