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scan.c
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scan.c
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/********************************************
scan.c
copyright 2008-2013,2014, Thomas E. Dickey
copyright 2010, Jonathan Nieder
copyright 1991-1996,2014, Michael D. Brennan
This is a source file for mawk, an implementation of
the AWK programming language.
Mawk is distributed without warranty under the terms of
the GNU General Public License, version 2, 1991.
********************************************/
/*
* $MawkId: scan.c,v 1.41 2014/08/21 20:05:54 tom Exp $
* @Log: scan.c,v @
* Revision 1.8 1996/07/28 21:47:05 mike
* gnuish patch
*
* Revision 1.7 1995/06/18 19:42:24 mike
* Remove some redundant declarations and add some prototypes
*
* Revision 1.6 1995/06/10 16:57:52 mike
* silently exit(0) if no program
* always add a '\n' on eof in scan_fillbuff()
*
* Revision 1.5 1995/06/06 00:18:33 mike
* change mawk_exit(1) to mawk_exit(2)
*
* Revision 1.4 1994/09/23 00:20:04 mike
* minor bug fix: handle \ in eat_nl()
*
* Revision 1.3 1993/07/17 00:45:21 mike
* indent
*
* Revision 1.2 1993/07/04 12:52:09 mike
* start on autoconfig changes
*
* Revision 1.1.1.1 1993/07/03 18:58:20 mike
* move source to cvs
*
* Revision 5.6 1993/02/13 21:57:33 mike
* merge patch3
*
* Revision 5.5 1993/01/01 21:30:48 mike
* split new_STRING() into new_STRING and new_STRING0
*
* Revision 5.4.1.1 1993/01/15 03:33:50 mike
* patch3: safer double to int conversion
*
* Revision 5.4 1992/11/29 18:57:50 mike
* field expressions convert to long so 16 bit and 32 bit
* systems behave the same
*
* Revision 5.3 1992/07/08 15:43:41 brennan
* patch2: length returns. I am a wimp
*
* Revision 5.2 1992/02/21 14:16:53 brennan
* fix: getline <=
*
* Revision 5.1 91/12/05 07:56:27 brennan
* 1.1 pre-release
*
*/
#include "mawk.h"
#include "scan.h"
#include "memory.h"
#include "field.h"
#include "init.h"
#include "fin.h"
#include "repl.h"
#include "code.h"
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include "files.h"
double double_zero = 0.0;
double double_one = 1.0;
/* static functions */
static void scan_fillbuff(void);
static void scan_open(void);
static int slow_next(void);
static void eat_comment(void);
static double collect_decimal(int, int *);
static int collect_string(void);
static int collect_RE(void);
/*-----------------------------
program file management
*----------------------------*/
char *pfile_name;
PFILE *pfile_list;
static STRING *program_string;
static UChar *buffer;
static UChar *buffp;
/* unsigned so it works with 8 bit chars */
static int program_fd;
static int eof_flag;
/* use unsigned chars for index into scan_code[] */
#define NextUChar(c) (UChar)(c = (char) next())
/* overused tmp buffer */
char string_buff[SPRINTF_LIMIT];
static void
string_too_long(void)
{
compile_error("string too long \"%.10s ...", string_buff);
mawk_exit(2);
}
#define CheckStringSize(ptr) \
if ((size_t)((ptr) - string_buff) >= sizeof(string_buff)) \
string_too_long()
void
scan_init(char *cmdline_program)
{
if (cmdline_program) {
program_fd = -1; /* command line program */
program_string = new_STRING0(strlen(cmdline_program) + 1);
strcpy(program_string->str, cmdline_program);
/* simulate file termination */
program_string->str[program_string->len - 1] = '\n';
buffp = (UChar *) program_string->str;
eof_flag = 1;
} else { /* program from file[s] */
scan_open();
buffp = buffer = (UChar *) zmalloc((size_t) (BUFFSZ + 1));
scan_fillbuff();
}
#ifdef OS2 /* OS/2 "extproc" is similar to #! */
if (strnicmp(buffp, "extproc ", 8) == 0)
eat_comment();
#endif
eat_nl(); /* scan to first token */
if (next() == 0) {
/* no program */
mawk_exit(0);
}
un_next();
}
static void
scan_open(void) /* open pfile_name */
{
if (pfile_name[0] == '-' && pfile_name[1] == 0) {
program_fd = 0;
} else if ((program_fd = open(pfile_name, O_RDONLY, 0)) == -1) {
errmsg(errno, "cannot open %s", pfile_name);
mawk_exit(2);
}
}
void
scan_cleanup(void)
{
if (program_fd >= 0)
zfree(buffer, (size_t) (BUFFSZ + 1));
if (program_string)
free_STRING(program_string);
if (program_fd > 0)
close(program_fd);
/* redefine SPACE as [ \t\n] */
scan_code['\n'] = (char) ((posix_space_flag && rs_shadow.type != SEP_MLR)
? SC_UNEXPECTED
: SC_SPACE);
scan_code['\f'] = SC_UNEXPECTED; /*value doesn't matter */
scan_code['\013'] = SC_UNEXPECTED; /* \v not space */
scan_code['\r'] = SC_UNEXPECTED;
}
/*--------------------------------
global variables shared by yyparse() and yylex()
and used for error messages too
*-------------------------------*/
int current_token = -1;
unsigned token_lineno;
unsigned compile_error_count;
int NR_flag; /* are we tracking NR */
int paren_cnt;
int brace_cnt;
int print_flag; /* changes meaning of '>' */
int getline_flag; /* changes meaning of '<' */
/*----------------------------------------
file reading functions
next() and un_next(c) are macros in scan.h
*---------------------*/
static unsigned lineno = 1;
static void
scan_fillbuff(void)
{
size_t r;
r = fillbuff(program_fd, (char *) buffer, (size_t) BUFFSZ);
if (r < BUFFSZ) {
eof_flag = 1;
/* make sure eof is terminated */
buffer[r] = '\n';
buffer[r + 1] = 0;
}
}
/* read one character -- slowly */
static int
slow_next(void)
{
while (*buffp == 0) {
if (!eof_flag) {
buffp = buffer;
scan_fillbuff();
} else if (pfile_list /* open another program file */ ) {
PFILE *q;
if (program_fd > 0)
close(program_fd);
eof_flag = 0;
pfile_name = pfile_list->fname;
q = pfile_list;
pfile_list = pfile_list->link;
ZFREE(q);
scan_open();
token_lineno = lineno = 1;
} else {
break; /* real eof */
}
}
return *buffp++; /* note can un_next() , eof which is zero */
}
static void
eat_comment(void)
{
register int c;
while (scan_code[NextUChar(c)] && (c != '\n')) {
; /* empty */
}
un_next();
}
/* this is how we handle extra semi-colons that are
now allowed to separate pattern-action blocks
A proof that they are useless clutter to the language:
we throw them away
*/
static void
eat_semi_colon(void)
/* eat one semi-colon on the current line */
{
register int c;
while (scan_code[NextUChar(c)] == SC_SPACE) {
; /* empty */
}
if (c != ';')
un_next();
}
void
eat_nl(void) /* eat all space including newlines */
{
while (1) {
switch (scan_code[(UChar) next()]) {
case SC_COMMENT:
eat_comment();
break;
case SC_NL:
lineno++;
/* fall thru */
case SC_SPACE:
break;
case SC_ESCAPE:
/* bug fix - surprised anyone did this,
a csh user with backslash dyslexia.(Not a joke)
*/
{
int c;
while (scan_code[NextUChar(c)] == SC_SPACE) {
; /* empty */
}
if (c == '\n')
token_lineno = ++lineno;
else if (c == 0) {
un_next();
return;
} else { /* error */
un_next();
/* can't un_next() twice so deal with it */
yylval.ival = '\\';
unexpected_char();
if (++compile_error_count == MAX_COMPILE_ERRORS)
mawk_exit(2);
return;
}
}
break;
default:
un_next();
return;
}
}
}
int
yylex(void)
{
register int c;
token_lineno = lineno;
#ifdef NO_LEAKS
memset(&yylval, 0, sizeof(yylval));
#endif
reswitch:
switch (scan_code[NextUChar(c)]) {
case 0:
ct_ret(EOF);
case SC_SPACE:
goto reswitch;
case SC_COMMENT:
eat_comment();
goto reswitch;
case SC_NL:
lineno++;
eat_nl();
ct_ret(NL);
case SC_ESCAPE:
while (scan_code[NextUChar(c)] == SC_SPACE) {
; /* empty */
};
if (c == '\n') {
token_lineno = ++lineno;
goto reswitch;
}
if (c == 0)
ct_ret(EOF);
un_next();
yylval.ival = '\\';
ct_ret(UNEXPECTED);
case SC_SEMI_COLON:
eat_nl();
ct_ret(SEMI_COLON);
case SC_LBRACE:
eat_nl();
brace_cnt++;
ct_ret(LBRACE);
case SC_PLUS:
switch (next()) {
case '+':
yylval.ival = '+';
string_buff[0] =
string_buff[1] = '+';
string_buff[2] = 0;
ct_ret(INC_or_DEC);
case '=':
ct_ret(ADD_ASG);
default:
un_next();
ct_ret(PLUS);
}
case SC_MINUS:
switch (next()) {
case '-':
yylval.ival = '-';
string_buff[0] =
string_buff[1] = '-';
string_buff[2] = 0;
ct_ret(INC_or_DEC);
case '=':
ct_ret(SUB_ASG);
default:
un_next();
ct_ret(MINUS);
}
case SC_COMMA:
eat_nl();
ct_ret(COMMA);
case SC_MUL:
test1_ret('=', MUL_ASG, MUL);
case SC_DIV:
{
static int can_precede_div[] =
{DOUBLE, STRING_, RPAREN, ID, D_ID, RE, RBOX, FIELD,
GETLINE, INC_or_DEC, -1};
int *p = can_precede_div;
do {
if (*p == current_token) {
if (*p != INC_or_DEC) {
test1_ret('=', DIV_ASG, DIV);
}
if (next() == '=') {
un_next();
ct_ret(collect_RE());
}
}
}
while (*++p != -1);
ct_ret(collect_RE());
}
case SC_MOD:
test1_ret('=', MOD_ASG, MOD);
case SC_POW:
test1_ret('=', POW_ASG, POW);
case SC_LPAREN:
paren_cnt++;
ct_ret(LPAREN);
case SC_RPAREN:
if (--paren_cnt < 0) {
compile_error("extra ')'");
paren_cnt = 0;
goto reswitch;
}
ct_ret(RPAREN);
case SC_LBOX:
ct_ret(LBOX);
case SC_RBOX:
ct_ret(RBOX);
case SC_MATCH:
string_buff[1] = '~';
string_buff[0] = 0;
yylval.ival = 1;
ct_ret(MATCH);
case SC_EQUAL:
test1_ret('=', EQ, ASSIGN);
case SC_NOT: /* ! */
if ((c = next()) == '~') {
string_buff[0] = '!';
string_buff[1] = '~';
string_buff[2] = 0;
yylval.ival = 0;
ct_ret(MATCH);
} else if (c == '=')
ct_ret(NEQ);
un_next();
ct_ret(NOT);
case SC_LT: /* '<' */
if (next() == '=')
ct_ret(LTE);
else
un_next();
if (getline_flag) {
getline_flag = 0;
ct_ret(IO_IN);
} else
ct_ret(LT);
case SC_GT: /* '>' */
if (print_flag && paren_cnt == 0) {
print_flag = 0;
/* there are 3 types of IO_OUT
-- build the error string in string_buff */
string_buff[0] = '>';
if (next() == '>') {
yylval.ival = F_APPEND;
string_buff[1] = '>';
string_buff[2] = 0;
} else {
un_next();
yylval.ival = F_TRUNC;
string_buff[1] = 0;
}
return current_token = IO_OUT;
}
test1_ret('=', GTE, GT);
case SC_OR:
if (next() == '|') {
eat_nl();
ct_ret(OR);
} else {
un_next();
if (print_flag && paren_cnt == 0) {
print_flag = 0;
yylval.ival = PIPE_OUT;
string_buff[0] = '|';
string_buff[1] = 0;
ct_ret(IO_OUT);
} else
ct_ret(PIPE);
}
case SC_AND:
if (next() == '&') {
eat_nl();
ct_ret(AND);
} else {
un_next();
yylval.ival = '&';
ct_ret(UNEXPECTED);
}
case SC_QMARK:
ct_ret(QMARK);
case SC_COLON:
ct_ret(COLON);
case SC_RBRACE:
if (--brace_cnt < 0) {
compile_error("extra '}'");
eat_semi_colon();
brace_cnt = 0;
goto reswitch;
}
if ((c = current_token) == NL || c == SEMI_COLON
|| c == SC_FAKE_SEMI_COLON || c == RBRACE) {
/* if the brace_cnt is zero , we've completed
a pattern action block. If the user insists
on adding a semi-colon on the same line
we will eat it. Note what we do below:
physical law -- conservation of semi-colons */
if (brace_cnt == 0)
eat_semi_colon();
eat_nl();
ct_ret(RBRACE);
}
/* supply missing semi-colon to statement that
precedes a '}' */
brace_cnt++;
un_next();
current_token = SC_FAKE_SEMI_COLON;
return SEMI_COLON;
case SC_DIGIT:
case SC_DOT:
{
double d;
int flag;
if ((d = collect_decimal(c, &flag)) == 0.0) {
if (flag)
ct_ret(flag);
else
yylval.ptr = (PTR) & double_zero;
} else if (d == 1.0) {
yylval.ptr = (PTR) & double_one;
} else {
yylval.ptr = (PTR) ZMALLOC(double);
*(double *) yylval.ptr = d;
}
ct_ret(DOUBLE);
}
case SC_DOLLAR: /* '$' */
{
double d;
int flag;
while (scan_code[NextUChar(c)] == SC_SPACE) {
; /* empty */
};
if (scan_code[c] != SC_DIGIT &&
scan_code[c] != SC_DOT) {
un_next();
ct_ret(DOLLAR);
}
/* compute field address at compile time */
if ((d = collect_decimal(c, &flag)) <= 0.0) {
if (flag)
ct_ret(flag); /* an error */
else
yylval.cp = &field[0];
} else {
int ival = d_to_I(d);
double dval = (double) ival;
if (dval != d) {
compile_error("$%g is invalid field index", d);
}
yylval.cp = field_ptr(ival);
}
ct_ret(FIELD);
}
case SC_DQUOTE:
return current_token = collect_string();
case SC_IDCHAR: /* collect an identifier */
{
char *p = string_buff + 1;
SYMTAB *stp;
string_buff[0] = (char) c;
while (1) {
CheckStringSize(p);
c = scan_code[NextUChar(*p++)];
if (c != SC_IDCHAR && c != SC_DIGIT)
break;
}
un_next();
*--p = 0;
switch ((stp = find(string_buff))->type) {
case ST_NONE:
/* check for function call before defined */
if (next() == '(') {
stp->type = ST_FUNCT;
stp->stval.fbp = (FBLOCK *)
zmalloc(sizeof(FBLOCK));
stp->stval.fbp->name = stp->name;
stp->stval.fbp->code = (INST *) 0;
stp->stval.fbp->size = 0;
yylval.fbp = stp->stval.fbp;
current_token = FUNCT_ID;
} else {
yylval.stp = stp;
current_token =
current_token == DOLLAR ? D_ID : ID;
}
un_next();
break;
case ST_NR:
NR_flag = 1;
stp->type = ST_VAR;
/* fall thru */
case ST_VAR:
case ST_ARRAY:
case ST_LOCAL_NONE:
case ST_LOCAL_VAR:
case ST_LOCAL_ARRAY:
yylval.stp = stp;
current_token =
current_token == DOLLAR ? D_ID : ID;
break;
case ST_ENV:
stp->type = ST_ARRAY;
stp->stval.array = new_ARRAY();
load_environ(stp->stval.array);
yylval.stp = stp;
current_token =
current_token == DOLLAR ? D_ID : ID;
break;
case ST_FUNCT:
yylval.fbp = stp->stval.fbp;
current_token = FUNCT_ID;
break;
case ST_KEYWORD:
current_token = stp->stval.kw;
break;
case ST_BUILTIN:
yylval.bip = stp->stval.bip;
current_token = BUILTIN;
break;
case ST_LENGTH:
yylval.bip = stp->stval.bip;
/* check for length alone, this is an ugly
hack */
while (scan_code[NextUChar(c)] == SC_SPACE) {
; /* empty */
};
un_next();
current_token = c == '(' ? BUILTIN : LENGTH;
break;
case ST_FIELD:
yylval.cp = stp->stval.cp;
current_token = FIELD;
break;
default:
bozo("find returned bad st type");
}
return current_token;
}
case SC_UNEXPECTED:
yylval.ival = c & 0xff;
ct_ret(UNEXPECTED);
}
return 0; /* never get here make lint happy */
}
/* collect a decimal constant in temp_buff.
Return the value and error conditions by reference */
static double
collect_decimal(int c, int *flag)
{
register char *p = string_buff + 1;
char *endp;
char *temp;
char *last_decimal = 0;
double d;
*flag = 0;
string_buff[0] = (char) c;
if (c == '.') {
last_decimal = p - 1;
CheckStringSize(p);
if (scan_code[NextUChar(*p++)] != SC_DIGIT) {
*flag = UNEXPECTED;
yylval.ival = '.';
return 0.0;
}
} else {
while (1) {
CheckStringSize(p);
if (scan_code[NextUChar(*p++)] != SC_DIGIT) {
break;
}
};
if (p[-1] == '.') {
last_decimal = p - 1;
} else {
un_next();
p--;
}
}
/* get rest of digits after decimal point */
while (1) {
CheckStringSize(p);
if (scan_code[NextUChar(*p++)] != SC_DIGIT) {
break;
}
}
/* check for exponent */
if (p[-1] != 'e' && p[-1] != 'E') {
un_next();
*--p = 0;
} else { /* get the exponent */
if (scan_code[NextUChar(*p)] != SC_DIGIT &&
*p != '-' && *p != '+') {
/* if we can, undo and try again */
if (buffp - buffer >= 2) {
un_next(); /* undo the last character */
un_next(); /* undo the 'e' */
*--p = 0;
} else {
*++p = 0;
*flag = BAD_DECIMAL;
return 0.0;
}
} else { /* get the rest of the exponent */
p++;
while (1) {
CheckStringSize(p);
if (scan_code[NextUChar(*p++)] != SC_DIGIT) {
break;
}
}
un_next();
*--p = 0;
}
}
#ifdef LOCALE
if (last_decimal && decimal_dot) {
*last_decimal = decimal_dot;
}
#endif
errno = 0; /* check for overflow/underflow */
d = strtod(string_buff, &temp);
endp = temp;
#ifndef STRTOD_UNDERFLOW_ON_ZERO_BUG
if (errno)
compile_error("%s : decimal %sflow", string_buff,
d == 0.0 ? "under" : "over");
#else /* ! sun4 bug */
if (errno && d != 0.0)
compile_error("%s : decimal overflow", string_buff);
#endif
if (endp < p) {
/* if we can, undo and try again */
if ((p - endp) < (buffp - buffer)) {
while (endp < p) {
un_next();
++endp;
}
} else {
*flag = BAD_DECIMAL;
return 0.0;
}
}
return d;
}
/*---------- process escape characters ---------------*/
static char hex_val['f' - 'A' + 1] =
{
10, 11, 12, 13, 14, 15, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
10, 11, 12, 13, 14, 15};
#define isoctal(x) ((x)>='0'&&(x)<='7')
#define hex_value(x) hex_val[(x)-'A']
#define ishex(x) (scan_code[x] == SC_DIGIT ||\
('A' <= (x) && (x) <= 'f' && hex_value(x)))
/* process one , two or three octal digits
moving a pointer forward by reference */
static int
octal(char **start_p)
{
register char *p = *start_p;
register unsigned x;
x = (unsigned) (*p++ - '0');
if (isoctal(*p)) {
x = (x << 3) + (unsigned) (*p++ - '0');
if (isoctal(*p))
x = (x << 3) + (unsigned) (*p++ - '0');
}
*start_p = p;
return (int) (x & 0xff);
}
/* process one or two hex digits
moving a pointer forward by reference */
static int
hex(char **start_p)
{
register UChar *p = (UChar *) * start_p;
register unsigned x;
unsigned t;
if (scan_code[*p] == SC_DIGIT)
x = (unsigned) (*p++ - '0');
else
x = (unsigned) hex_value(*p++);
if (scan_code[*p] == SC_DIGIT)
x = (x << 4) + *p++ - '0';
else if ('A' <= *p && *p <= 'f' && (t = (unsigned) hex_value(*p))) {
x = (x << 4) + t;
p++;
}
*start_p = (char *) p;
return (int) x;
}
#define ET_END 9
static struct {
char in, out;
}
/* *INDENT-OFF* */
escape_test[ET_END + 1] =
{
{'n', '\n'},
{'t', '\t'},
{'f', '\f'},
{'b', '\b'},
{'r', '\r'},
{'a', '\07'},
{'v', '\013'},
{'\\', '\\'},
{'\"', '\"'},
{0, 0}
};
/* *INDENT-ON* */
/* process the escape characters in a string, in place . */ char *
rm_escape(char *s, size_t *lenp)
{
register char *p, *q;
char *t;
int i;
q = p = s;
while (*p) {
if (*p == '\\') {
escape_test[ET_END].in = *++p; /* sentinal */
i = 0;
while (escape_test[i].in != *p)
i++;
if (i != ET_END) /* in table */
{
p++;
*q++ = escape_test[i].out;
} else if (isoctal(*p)) {
t = p;
*q++ = (char) octal(&t);
p = t;
} else if (*p == 'x' && ishex(*(UChar *) (p + 1))) {
t = p + 1;
*q++ = (char) hex(&t);
p = t;
} else if (*p == 0) /* can only happen with command line assign */
*q++ = '\\';
else { /* not an escape sequence */
*q++ = '\\';
*q++ = *p++;
}
} else
*q++ = *p++;
}
*q = 0;
if (lenp != 0)
*lenp = (unsigned) (q - s);
return s;
}
static int
collect_string(void)
{
register char *p = string_buff;
int c;
int e_flag = 0; /* on if have an escape char */
size_t len_buff;
while (1) {
CheckStringSize(p);
switch (scan_code[NextUChar(*p++)]) {