1007 lines
23 KiB
Plaintext
1007 lines
23 KiB
Plaintext
/* Parse C expressions for CCCP.
|
||
Copyright (C) 1987, 1992 Free Software Foundation.
|
||
|
||
This program is free software; you can redistribute it and/or modify it
|
||
under the terms of the GNU General Public License as published by the
|
||
Free Software Foundation; either version 2, or (at your option) any
|
||
later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with this program; if not, write to the Free Software
|
||
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
|
||
|
||
In other words, you are welcome to use, share and improve this program.
|
||
You are forbidden to forbid anyone else to use, share and improve
|
||
what you give them. Help stamp out software-hoarding!
|
||
|
||
Adapted from expread.y of GDB by Paul Rubin, July 1986. */
|
||
|
||
/* Parse a C expression from text in a string */
|
||
|
||
%{
|
||
#include "config.h"
|
||
#include <setjmp.h>
|
||
/* #define YYDEBUG 1 */
|
||
|
||
#ifdef MULTIBYTE_CHARS
|
||
#include <stdlib.h>
|
||
#include <locale.h>
|
||
#endif
|
||
|
||
#include <stdio.h>
|
||
|
||
typedef unsigned char U_CHAR;
|
||
|
||
/* This is used for communicating lists of keywords with cccp.c. */
|
||
struct arglist {
|
||
struct arglist *next;
|
||
U_CHAR *name;
|
||
int length;
|
||
int argno;
|
||
};
|
||
|
||
/* Define a generic NULL if one hasn't already been defined. */
|
||
|
||
#ifndef NULL
|
||
#define NULL 0
|
||
#endif
|
||
|
||
#ifndef GENERIC_PTR
|
||
#if defined (USE_PROTOTYPES) ? USE_PROTOTYPES : defined (__STDC__)
|
||
#define GENERIC_PTR void *
|
||
#else
|
||
#define GENERIC_PTR char *
|
||
#endif
|
||
#endif
|
||
|
||
#ifndef NULL_PTR
|
||
#define NULL_PTR ((GENERIC_PTR)0)
|
||
#endif
|
||
|
||
int yylex ();
|
||
void yyerror ();
|
||
int expression_value;
|
||
|
||
static jmp_buf parse_return_error;
|
||
|
||
/* Nonzero means count most punctuation as part of a name. */
|
||
static int keyword_parsing = 0;
|
||
|
||
/* some external tables of character types */
|
||
extern unsigned char is_idstart[], is_idchar[], is_hor_space[];
|
||
|
||
extern char *xmalloc ();
|
||
|
||
/* Flag for -pedantic. */
|
||
extern int pedantic;
|
||
|
||
/* Flag for -traditional. */
|
||
extern int traditional;
|
||
|
||
#ifndef CHAR_TYPE_SIZE
|
||
#define CHAR_TYPE_SIZE BITS_PER_UNIT
|
||
#endif
|
||
|
||
#ifndef INT_TYPE_SIZE
|
||
#define INT_TYPE_SIZE BITS_PER_WORD
|
||
#endif
|
||
|
||
#ifndef LONG_TYPE_SIZE
|
||
#define LONG_TYPE_SIZE BITS_PER_WORD
|
||
#endif
|
||
|
||
#ifndef WCHAR_TYPE_SIZE
|
||
#define WCHAR_TYPE_SIZE INT_TYPE_SIZE
|
||
#endif
|
||
|
||
/* Yield nonzero if adding two numbers with A's and B's signs can yield a
|
||
number with SUM's sign, where A, B, and SUM are all C integers. */
|
||
#define possible_sum_sign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0)
|
||
|
||
static void integer_overflow ();
|
||
static long left_shift ();
|
||
static long right_shift ();
|
||
%}
|
||
|
||
%union {
|
||
struct constant {long value; int unsignedp;} integer;
|
||
struct name {U_CHAR *address; int length;} name;
|
||
struct arglist *keywords;
|
||
int voidval;
|
||
char *sval;
|
||
}
|
||
|
||
%type <integer> exp exp1 start
|
||
%type <keywords> keywords
|
||
%token <integer> INT CHAR
|
||
%token <name> NAME
|
||
%token <integer> ERROR
|
||
|
||
%right '?' ':'
|
||
%left ','
|
||
%left OR
|
||
%left AND
|
||
%left '|'
|
||
%left '^'
|
||
%left '&'
|
||
%left EQUAL NOTEQUAL
|
||
%left '<' '>' LEQ GEQ
|
||
%left LSH RSH
|
||
%left '+' '-'
|
||
%left '*' '/' '%'
|
||
%right UNARY
|
||
|
||
/* %expect 40 */
|
||
|
||
%%
|
||
|
||
start : exp1
|
||
{ expression_value = $1.value; }
|
||
;
|
||
|
||
/* Expressions, including the comma operator. */
|
||
exp1 : exp
|
||
| exp1 ',' exp
|
||
{ if (pedantic)
|
||
pedwarn ("comma operator in operand of `#if'");
|
||
$$ = $3; }
|
||
;
|
||
|
||
/* Expressions, not including the comma operator. */
|
||
exp : '-' exp %prec UNARY
|
||
{ $$.value = - $2.value;
|
||
if (($$.value & $2.value) < 0 && ! $2.unsignedp)
|
||
integer_overflow ();
|
||
$$.unsignedp = $2.unsignedp; }
|
||
| '!' exp %prec UNARY
|
||
{ $$.value = ! $2.value;
|
||
$$.unsignedp = 0; }
|
||
| '+' exp %prec UNARY
|
||
{ $$ = $2; }
|
||
| '~' exp %prec UNARY
|
||
{ $$.value = ~ $2.value;
|
||
$$.unsignedp = $2.unsignedp; }
|
||
| '#' NAME
|
||
{ $$.value = check_assertion ($2.address, $2.length,
|
||
0, NULL_PTR);
|
||
$$.unsignedp = 0; }
|
||
| '#' NAME
|
||
{ keyword_parsing = 1; }
|
||
'(' keywords ')'
|
||
{ $$.value = check_assertion ($2.address, $2.length,
|
||
1, $5);
|
||
keyword_parsing = 0;
|
||
$$.unsignedp = 0; }
|
||
| '(' exp1 ')'
|
||
{ $$ = $2; }
|
||
;
|
||
|
||
/* Binary operators in order of decreasing precedence. */
|
||
exp : exp '*' exp
|
||
{ $$.unsignedp = $1.unsignedp || $3.unsignedp;
|
||
if ($$.unsignedp)
|
||
$$.value = (unsigned long) $1.value * $3.value;
|
||
else
|
||
{
|
||
$$.value = $1.value * $3.value;
|
||
if ($1.value
|
||
&& ($$.value / $1.value != $3.value
|
||
|| ($$.value & $1.value & $3.value) < 0))
|
||
integer_overflow ();
|
||
} }
|
||
| exp '/' exp
|
||
{ if ($3.value == 0)
|
||
{
|
||
error ("division by zero in #if");
|
||
$3.value = 1;
|
||
}
|
||
$$.unsignedp = $1.unsignedp || $3.unsignedp;
|
||
if ($$.unsignedp)
|
||
$$.value = (unsigned long) $1.value / $3.value;
|
||
else
|
||
{
|
||
$$.value = $1.value / $3.value;
|
||
if (($$.value & $1.value & $3.value) < 0)
|
||
integer_overflow ();
|
||
} }
|
||
| exp '%' exp
|
||
{ if ($3.value == 0)
|
||
{
|
||
error ("division by zero in #if");
|
||
$3.value = 1;
|
||
}
|
||
$$.unsignedp = $1.unsignedp || $3.unsignedp;
|
||
if ($$.unsignedp)
|
||
$$.value = (unsigned long) $1.value % $3.value;
|
||
else
|
||
$$.value = $1.value % $3.value; }
|
||
| exp '+' exp
|
||
{ $$.value = $1.value + $3.value;
|
||
$$.unsignedp = $1.unsignedp || $3.unsignedp;
|
||
if (! $$.unsignedp
|
||
&& ! possible_sum_sign ($1.value, $3.value,
|
||
$$.value))
|
||
integer_overflow (); }
|
||
| exp '-' exp
|
||
{ $$.value = $1.value - $3.value;
|
||
$$.unsignedp = $1.unsignedp || $3.unsignedp;
|
||
if (! $$.unsignedp
|
||
&& ! possible_sum_sign ($$.value, $3.value,
|
||
$1.value))
|
||
integer_overflow (); }
|
||
| exp LSH exp
|
||
{ $$.unsignedp = $1.unsignedp;
|
||
if ($3.value < 0 && ! $3.unsignedp)
|
||
$$.value = right_shift (&$1, -$3.value);
|
||
else
|
||
$$.value = left_shift (&$1, $3.value); }
|
||
| exp RSH exp
|
||
{ $$.unsignedp = $1.unsignedp;
|
||
if ($3.value < 0 && ! $3.unsignedp)
|
||
$$.value = left_shift (&$1, -$3.value);
|
||
else
|
||
$$.value = right_shift (&$1, $3.value); }
|
||
| exp EQUAL exp
|
||
{ $$.value = ($1.value == $3.value);
|
||
$$.unsignedp = 0; }
|
||
| exp NOTEQUAL exp
|
||
{ $$.value = ($1.value != $3.value);
|
||
$$.unsignedp = 0; }
|
||
| exp LEQ exp
|
||
{ $$.unsignedp = 0;
|
||
if ($1.unsignedp || $3.unsignedp)
|
||
$$.value = (unsigned long) $1.value <= $3.value;
|
||
else
|
||
$$.value = $1.value <= $3.value; }
|
||
| exp GEQ exp
|
||
{ $$.unsignedp = 0;
|
||
if ($1.unsignedp || $3.unsignedp)
|
||
$$.value = (unsigned long) $1.value >= $3.value;
|
||
else
|
||
$$.value = $1.value >= $3.value; }
|
||
| exp '<' exp
|
||
{ $$.unsignedp = 0;
|
||
if ($1.unsignedp || $3.unsignedp)
|
||
$$.value = (unsigned long) $1.value < $3.value;
|
||
else
|
||
$$.value = $1.value < $3.value; }
|
||
| exp '>' exp
|
||
{ $$.unsignedp = 0;
|
||
if ($1.unsignedp || $3.unsignedp)
|
||
$$.value = (unsigned long) $1.value > $3.value;
|
||
else
|
||
$$.value = $1.value > $3.value; }
|
||
| exp '&' exp
|
||
{ $$.value = $1.value & $3.value;
|
||
$$.unsignedp = $1.unsignedp || $3.unsignedp; }
|
||
| exp '^' exp
|
||
{ $$.value = $1.value ^ $3.value;
|
||
$$.unsignedp = $1.unsignedp || $3.unsignedp; }
|
||
| exp '|' exp
|
||
{ $$.value = $1.value | $3.value;
|
||
$$.unsignedp = $1.unsignedp || $3.unsignedp; }
|
||
| exp AND exp
|
||
{ $$.value = ($1.value && $3.value);
|
||
$$.unsignedp = 0; }
|
||
| exp OR exp
|
||
{ $$.value = ($1.value || $3.value);
|
||
$$.unsignedp = 0; }
|
||
| exp '?' exp ':' exp
|
||
{ $$.value = $1.value ? $3.value : $5.value;
|
||
$$.unsignedp = $3.unsignedp || $5.unsignedp; }
|
||
| INT
|
||
{ $$ = yylval.integer; }
|
||
| CHAR
|
||
{ $$ = yylval.integer; }
|
||
| NAME
|
||
{ $$.value = 0;
|
||
$$.unsignedp = 0; }
|
||
;
|
||
|
||
keywords :
|
||
{ $$ = 0; }
|
||
| '(' keywords ')' keywords
|
||
{ struct arglist *temp;
|
||
$$ = (struct arglist *) xmalloc (sizeof (struct arglist));
|
||
$$->next = $2;
|
||
$$->name = (U_CHAR *) "(";
|
||
$$->length = 1;
|
||
temp = $$;
|
||
while (temp != 0 && temp->next != 0)
|
||
temp = temp->next;
|
||
temp->next = (struct arglist *) xmalloc (sizeof (struct arglist));
|
||
temp->next->next = $4;
|
||
temp->next->name = (U_CHAR *) ")";
|
||
temp->next->length = 1; }
|
||
| NAME keywords
|
||
{ $$ = (struct arglist *) xmalloc (sizeof (struct arglist));
|
||
$$->name = $1.address;
|
||
$$->length = $1.length;
|
||
$$->next = $2; }
|
||
;
|
||
%%
|
||
|
||
/* During parsing of a C expression, the pointer to the next character
|
||
is in this variable. */
|
||
|
||
static char *lexptr;
|
||
|
||
/* Take care of parsing a number (anything that starts with a digit).
|
||
Set yylval and return the token type; update lexptr.
|
||
LEN is the number of characters in it. */
|
||
|
||
/* maybe needs to actually deal with floating point numbers */
|
||
|
||
int
|
||
parse_number (olen)
|
||
int olen;
|
||
{
|
||
register char *p = lexptr;
|
||
register int c;
|
||
register unsigned long n = 0, nd, ULONG_MAX_over_base;
|
||
register int base = 10;
|
||
register int len = olen;
|
||
register int overflow = 0;
|
||
register int digit, largest_digit = 0;
|
||
int spec_long = 0;
|
||
|
||
for (c = 0; c < len; c++)
|
||
if (p[c] == '.') {
|
||
/* It's a float since it contains a point. */
|
||
yyerror ("floating point numbers not allowed in #if expressions");
|
||
return ERROR;
|
||
}
|
||
|
||
yylval.integer.unsignedp = 0;
|
||
|
||
if (len >= 3 && (!strncmp (p, "0x", 2) || !strncmp (p, "0X", 2))) {
|
||
p += 2;
|
||
base = 16;
|
||
len -= 2;
|
||
}
|
||
else if (*p == '0')
|
||
base = 8;
|
||
|
||
ULONG_MAX_over_base = (unsigned long) -1 / base;
|
||
|
||
for (; len > 0; len--) {
|
||
c = *p++;
|
||
|
||
if (c >= '0' && c <= '9')
|
||
digit = c - '0';
|
||
else if (base == 16 && c >= 'a' && c <= 'f')
|
||
digit = c - 'a' + 10;
|
||
else if (base == 16 && c >= 'A' && c <= 'F')
|
||
digit = c - 'A' + 10;
|
||
else {
|
||
/* `l' means long, and `u' means unsigned. */
|
||
while (1) {
|
||
if (c == 'l' || c == 'L')
|
||
{
|
||
if (spec_long)
|
||
yyerror ("two `l's in integer constant");
|
||
spec_long = 1;
|
||
}
|
||
else if (c == 'u' || c == 'U')
|
||
{
|
||
if (yylval.integer.unsignedp)
|
||
yyerror ("two `u's in integer constant");
|
||
yylval.integer.unsignedp = 1;
|
||
}
|
||
else
|
||
break;
|
||
|
||
if (--len == 0)
|
||
break;
|
||
c = *p++;
|
||
}
|
||
/* Don't look for any more digits after the suffixes. */
|
||
break;
|
||
}
|
||
if (largest_digit < digit)
|
||
largest_digit = digit;
|
||
nd = n * base + digit;
|
||
overflow |= ULONG_MAX_over_base < n | nd < n;
|
||
n = nd;
|
||
}
|
||
|
||
if (len != 0) {
|
||
yyerror ("Invalid number in #if expression");
|
||
return ERROR;
|
||
}
|
||
|
||
if (base <= largest_digit)
|
||
warning ("integer constant contains digits beyond the radix");
|
||
|
||
if (overflow)
|
||
warning ("integer constant out of range");
|
||
|
||
/* If too big to be signed, consider it unsigned. */
|
||
if ((long) n < 0 && ! yylval.integer.unsignedp)
|
||
{
|
||
if (base == 10)
|
||
warning ("integer constant is so large that it is unsigned");
|
||
yylval.integer.unsignedp = 1;
|
||
}
|
||
|
||
lexptr = p;
|
||
yylval.integer.value = n;
|
||
return INT;
|
||
}
|
||
|
||
struct token {
|
||
char *operator;
|
||
int token;
|
||
};
|
||
|
||
static struct token tokentab2[] = {
|
||
{"&&", AND},
|
||
{"||", OR},
|
||
{"<<", LSH},
|
||
{">>", RSH},
|
||
{"==", EQUAL},
|
||
{"!=", NOTEQUAL},
|
||
{"<=", LEQ},
|
||
{">=", GEQ},
|
||
{"++", ERROR},
|
||
{"--", ERROR},
|
||
{NULL, ERROR}
|
||
};
|
||
|
||
/* Read one token, getting characters through lexptr. */
|
||
|
||
int
|
||
yylex ()
|
||
{
|
||
register int c;
|
||
register int namelen;
|
||
register unsigned char *tokstart;
|
||
register struct token *toktab;
|
||
int wide_flag;
|
||
|
||
retry:
|
||
|
||
tokstart = (unsigned char *) lexptr;
|
||
c = *tokstart;
|
||
/* See if it is a special token of length 2. */
|
||
if (! keyword_parsing)
|
||
for (toktab = tokentab2; toktab->operator != NULL; toktab++)
|
||
if (c == *toktab->operator && tokstart[1] == toktab->operator[1]) {
|
||
lexptr += 2;
|
||
if (toktab->token == ERROR)
|
||
{
|
||
char *buf = (char *) alloca (40);
|
||
sprintf (buf, "`%s' not allowed in operand of `#if'", toktab->operator);
|
||
yyerror (buf);
|
||
}
|
||
return toktab->token;
|
||
}
|
||
|
||
switch (c) {
|
||
case 0:
|
||
return 0;
|
||
|
||
case ' ':
|
||
case '\t':
|
||
case '\r':
|
||
case '\n':
|
||
lexptr++;
|
||
goto retry;
|
||
|
||
case 'L':
|
||
/* Capital L may start a wide-string or wide-character constant. */
|
||
if (lexptr[1] == '\'')
|
||
{
|
||
lexptr++;
|
||
wide_flag = 1;
|
||
goto char_constant;
|
||
}
|
||
if (lexptr[1] == '"')
|
||
{
|
||
lexptr++;
|
||
wide_flag = 1;
|
||
goto string_constant;
|
||
}
|
||
break;
|
||
|
||
case '\'':
|
||
wide_flag = 0;
|
||
char_constant:
|
||
lexptr++;
|
||
if (keyword_parsing) {
|
||
char *start_ptr = lexptr - 1;
|
||
while (1) {
|
||
c = *lexptr++;
|
||
if (c == '\\')
|
||
c = parse_escape (&lexptr);
|
||
else if (c == '\'')
|
||
break;
|
||
}
|
||
yylval.name.address = tokstart;
|
||
yylval.name.length = lexptr - start_ptr;
|
||
return NAME;
|
||
}
|
||
|
||
/* This code for reading a character constant
|
||
handles multicharacter constants and wide characters.
|
||
It is mostly copied from c-lex.c. */
|
||
{
|
||
register int result = 0;
|
||
register num_chars = 0;
|
||
unsigned width = CHAR_TYPE_SIZE;
|
||
int max_chars;
|
||
char *token_buffer;
|
||
|
||
if (wide_flag)
|
||
{
|
||
width = WCHAR_TYPE_SIZE;
|
||
#ifdef MULTIBYTE_CHARS
|
||
max_chars = MB_CUR_MAX;
|
||
#else
|
||
max_chars = 1;
|
||
#endif
|
||
}
|
||
else
|
||
max_chars = LONG_TYPE_SIZE / width;
|
||
|
||
token_buffer = (char *) alloca (max_chars + 1);
|
||
|
||
while (1)
|
||
{
|
||
c = *lexptr++;
|
||
|
||
if (c == '\'' || c == EOF)
|
||
break;
|
||
|
||
if (c == '\\')
|
||
{
|
||
c = parse_escape (&lexptr);
|
||
if (width < HOST_BITS_PER_INT
|
||
&& (unsigned) c >= (1 << width))
|
||
pedwarn ("escape sequence out of range for character");
|
||
}
|
||
|
||
num_chars++;
|
||
|
||
/* Merge character into result; ignore excess chars. */
|
||
if (num_chars < max_chars + 1)
|
||
{
|
||
if (width < HOST_BITS_PER_INT)
|
||
result = (result << width) | (c & ((1 << width) - 1));
|
||
else
|
||
result = c;
|
||
token_buffer[num_chars - 1] = c;
|
||
}
|
||
}
|
||
|
||
token_buffer[num_chars] = 0;
|
||
|
||
if (c != '\'')
|
||
error ("malformatted character constant");
|
||
else if (num_chars == 0)
|
||
error ("empty character constant");
|
||
else if (num_chars > max_chars)
|
||
{
|
||
num_chars = max_chars;
|
||
error ("character constant too long");
|
||
}
|
||
else if (num_chars != 1 && ! traditional)
|
||
warning ("multi-character character constant");
|
||
|
||
/* If char type is signed, sign-extend the constant. */
|
||
if (! wide_flag)
|
||
{
|
||
int num_bits = num_chars * width;
|
||
|
||
if (lookup ("__CHAR_UNSIGNED__", sizeof ("__CHAR_UNSIGNED__")-1, -1)
|
||
|| ((result >> (num_bits - 1)) & 1) == 0)
|
||
yylval.integer.value
|
||
= result & ((unsigned long) ~0 >> (HOST_BITS_PER_LONG - num_bits));
|
||
else
|
||
yylval.integer.value
|
||
= result | ~((unsigned long) ~0 >> (HOST_BITS_PER_LONG - num_bits));
|
||
}
|
||
else
|
||
{
|
||
#ifdef MULTIBYTE_CHARS
|
||
/* Set the initial shift state and convert the next sequence. */
|
||
result = 0;
|
||
/* In all locales L'\0' is zero and mbtowc will return zero,
|
||
so don't use it. */
|
||
if (num_chars > 1
|
||
|| (num_chars == 1 && token_buffer[0] != '\0'))
|
||
{
|
||
wchar_t wc;
|
||
(void) mbtowc (NULL_PTR, NULL_PTR, 0);
|
||
if (mbtowc (& wc, token_buffer, num_chars) == num_chars)
|
||
result = wc;
|
||
else
|
||
warning ("Ignoring invalid multibyte character");
|
||
}
|
||
#endif
|
||
yylval.integer.value = result;
|
||
}
|
||
}
|
||
|
||
/* This is always a signed type. */
|
||
yylval.integer.unsignedp = 0;
|
||
|
||
return CHAR;
|
||
|
||
/* some of these chars are invalid in constant expressions;
|
||
maybe do something about them later */
|
||
case '/':
|
||
case '+':
|
||
case '-':
|
||
case '*':
|
||
case '%':
|
||
case '|':
|
||
case '&':
|
||
case '^':
|
||
case '~':
|
||
case '!':
|
||
case '@':
|
||
case '<':
|
||
case '>':
|
||
case '[':
|
||
case ']':
|
||
case '.':
|
||
case '?':
|
||
case ':':
|
||
case '=':
|
||
case '{':
|
||
case '}':
|
||
case ',':
|
||
case '#':
|
||
if (keyword_parsing)
|
||
break;
|
||
case '(':
|
||
case ')':
|
||
lexptr++;
|
||
return c;
|
||
|
||
case '"':
|
||
string_constant:
|
||
if (keyword_parsing) {
|
||
char *start_ptr = lexptr;
|
||
lexptr++;
|
||
while (1) {
|
||
c = *lexptr++;
|
||
if (c == '\\')
|
||
c = parse_escape (&lexptr);
|
||
else if (c == '"')
|
||
break;
|
||
}
|
||
yylval.name.address = tokstart;
|
||
yylval.name.length = lexptr - start_ptr;
|
||
return NAME;
|
||
}
|
||
yyerror ("string constants not allowed in #if expressions");
|
||
return ERROR;
|
||
}
|
||
|
||
if (c >= '0' && c <= '9' && !keyword_parsing) {
|
||
/* It's a number */
|
||
for (namelen = 0;
|
||
c = tokstart[namelen], is_idchar[c] || c == '.';
|
||
namelen++)
|
||
;
|
||
return parse_number (namelen);
|
||
}
|
||
|
||
/* It is a name. See how long it is. */
|
||
|
||
if (keyword_parsing) {
|
||
for (namelen = 0;; namelen++) {
|
||
if (is_hor_space[tokstart[namelen]])
|
||
break;
|
||
if (tokstart[namelen] == '(' || tokstart[namelen] == ')')
|
||
break;
|
||
if (tokstart[namelen] == '"' || tokstart[namelen] == '\'')
|
||
break;
|
||
}
|
||
} else {
|
||
if (!is_idstart[c]) {
|
||
yyerror ("Invalid token in expression");
|
||
return ERROR;
|
||
}
|
||
|
||
for (namelen = 0; is_idchar[tokstart[namelen]]; namelen++)
|
||
;
|
||
}
|
||
|
||
lexptr += namelen;
|
||
yylval.name.address = tokstart;
|
||
yylval.name.length = namelen;
|
||
return NAME;
|
||
}
|
||
|
||
|
||
/* Parse a C escape sequence. STRING_PTR points to a variable
|
||
containing a pointer to the string to parse. That pointer
|
||
is updated past the characters we use. The value of the
|
||
escape sequence is returned.
|
||
|
||
A negative value means the sequence \ newline was seen,
|
||
which is supposed to be equivalent to nothing at all.
|
||
|
||
If \ is followed by a null character, we return a negative
|
||
value and leave the string pointer pointing at the null character.
|
||
|
||
If \ is followed by 000, we return 0 and leave the string pointer
|
||
after the zeros. A value of 0 does not mean end of string. */
|
||
|
||
int
|
||
parse_escape (string_ptr)
|
||
char **string_ptr;
|
||
{
|
||
register int c = *(*string_ptr)++;
|
||
switch (c)
|
||
{
|
||
case 'a':
|
||
return TARGET_BELL;
|
||
case 'b':
|
||
return TARGET_BS;
|
||
case 'e':
|
||
case 'E':
|
||
if (pedantic)
|
||
pedwarn ("non-ANSI-standard escape sequence, `\\%c'", c);
|
||
return 033;
|
||
case 'f':
|
||
return TARGET_FF;
|
||
case 'n':
|
||
return TARGET_NEWLINE;
|
||
case 'r':
|
||
return TARGET_CR;
|
||
case 't':
|
||
return TARGET_TAB;
|
||
case 'v':
|
||
return TARGET_VT;
|
||
case '\n':
|
||
return -2;
|
||
case 0:
|
||
(*string_ptr)--;
|
||
return 0;
|
||
|
||
case '0':
|
||
case '1':
|
||
case '2':
|
||
case '3':
|
||
case '4':
|
||
case '5':
|
||
case '6':
|
||
case '7':
|
||
{
|
||
register int i = c - '0';
|
||
register int count = 0;
|
||
while (++count < 3)
|
||
{
|
||
c = *(*string_ptr)++;
|
||
if (c >= '0' && c <= '7')
|
||
i = (i << 3) + c - '0';
|
||
else
|
||
{
|
||
(*string_ptr)--;
|
||
break;
|
||
}
|
||
}
|
||
if ((i & ~((1 << CHAR_TYPE_SIZE) - 1)) != 0)
|
||
{
|
||
i &= (1 << CHAR_TYPE_SIZE) - 1;
|
||
warning ("octal character constant does not fit in a byte");
|
||
}
|
||
return i;
|
||
}
|
||
case 'x':
|
||
{
|
||
register unsigned i = 0, overflow = 0, digits_found = 0, digit;
|
||
for (;;)
|
||
{
|
||
c = *(*string_ptr)++;
|
||
if (c >= '0' && c <= '9')
|
||
digit = c - '0';
|
||
else if (c >= 'a' && c <= 'f')
|
||
digit = c - 'a' + 10;
|
||
else if (c >= 'A' && c <= 'F')
|
||
digit = c - 'A' + 10;
|
||
else
|
||
{
|
||
(*string_ptr)--;
|
||
break;
|
||
}
|
||
overflow |= i ^ (i << 4 >> 4);
|
||
i = (i << 4) + digit;
|
||
digits_found = 1;
|
||
}
|
||
if (!digits_found)
|
||
yyerror ("\\x used with no following hex digits");
|
||
if (overflow | (i & ~((1 << BITS_PER_UNIT) - 1)))
|
||
{
|
||
i &= (1 << BITS_PER_UNIT) - 1;
|
||
warning ("hex character constant does not fit in a byte");
|
||
}
|
||
return i;
|
||
}
|
||
default:
|
||
return c;
|
||
}
|
||
}
|
||
|
||
void
|
||
yyerror (s)
|
||
char *s;
|
||
{
|
||
error (s);
|
||
longjmp (parse_return_error, 1);
|
||
}
|
||
|
||
static void
|
||
integer_overflow ()
|
||
{
|
||
if (pedantic)
|
||
pedwarn ("integer overflow in preprocessor expression");
|
||
}
|
||
|
||
static long
|
||
left_shift (a, b)
|
||
struct constant *a;
|
||
unsigned long b;
|
||
{
|
||
if (b >= HOST_BITS_PER_LONG)
|
||
{
|
||
if (! a->unsignedp && a->value != 0)
|
||
integer_overflow ();
|
||
return 0;
|
||
}
|
||
else if (a->unsignedp)
|
||
return (unsigned long) a->value << b;
|
||
else
|
||
{
|
||
long l = a->value << b;
|
||
if (l >> b != a->value)
|
||
integer_overflow ();
|
||
return l;
|
||
}
|
||
}
|
||
|
||
static long
|
||
right_shift (a, b)
|
||
struct constant *a;
|
||
unsigned long b;
|
||
{
|
||
if (b >= HOST_BITS_PER_LONG)
|
||
return a->unsignedp ? 0 : a->value >> (HOST_BITS_PER_LONG - 1);
|
||
else if (a->unsignedp)
|
||
return (unsigned long) a->value >> b;
|
||
else
|
||
return a->value >> b;
|
||
}
|
||
|
||
/* This page contains the entry point to this file. */
|
||
|
||
/* Parse STRING as an expression, and complain if this fails
|
||
to use up all of the contents of STRING. */
|
||
/* We do not support C comments. They should be removed before
|
||
this function is called. */
|
||
|
||
int
|
||
parse_c_expression (string)
|
||
char *string;
|
||
{
|
||
lexptr = string;
|
||
|
||
if (lexptr == 0 || *lexptr == 0) {
|
||
error ("empty #if expression");
|
||
return 0; /* don't include the #if group */
|
||
}
|
||
|
||
/* if there is some sort of scanning error, just return 0 and assume
|
||
the parsing routine has printed an error message somewhere.
|
||
there is surely a better thing to do than this. */
|
||
if (setjmp (parse_return_error))
|
||
return 0;
|
||
|
||
if (yyparse ())
|
||
return 0; /* actually this is never reached
|
||
the way things stand. */
|
||
if (*lexptr)
|
||
error ("Junk after end of expression.");
|
||
|
||
return expression_value; /* set by yyparse () */
|
||
}
|
||
|
||
#ifdef TEST_EXP_READER
|
||
extern int yydebug;
|
||
|
||
/* Main program for testing purposes. */
|
||
int
|
||
main ()
|
||
{
|
||
int n, c;
|
||
char buf[1024];
|
||
|
||
/*
|
||
yydebug = 1;
|
||
*/
|
||
initialize_random_junk ();
|
||
|
||
for (;;) {
|
||
printf ("enter expression: ");
|
||
n = 0;
|
||
while ((buf[n] = getchar ()) != '\n' && buf[n] != EOF)
|
||
n++;
|
||
if (buf[n] == EOF)
|
||
break;
|
||
buf[n] = '\0';
|
||
printf ("parser returned %d\n", parse_c_expression (buf));
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* table to tell if char can be part of a C identifier. */
|
||
unsigned char is_idchar[256];
|
||
/* table to tell if char can be first char of a c identifier. */
|
||
unsigned char is_idstart[256];
|
||
/* table to tell if c is horizontal space. isspace () thinks that
|
||
newline is space; this is not a good idea for this program. */
|
||
char is_hor_space[256];
|
||
|
||
/*
|
||
* initialize random junk in the hash table and maybe other places
|
||
*/
|
||
initialize_random_junk ()
|
||
{
|
||
register int i;
|
||
|
||
/*
|
||
* Set up is_idchar and is_idstart tables. These should be
|
||
* faster than saying (is_alpha (c) || c == '_'), etc.
|
||
* Must do set up these things before calling any routines tthat
|
||
* refer to them.
|
||
*/
|
||
for (i = 'a'; i <= 'z'; i++) {
|
||
++is_idchar[i - 'a' + 'A'];
|
||
++is_idchar[i];
|
||
++is_idstart[i - 'a' + 'A'];
|
||
++is_idstart[i];
|
||
}
|
||
for (i = '0'; i <= '9'; i++)
|
||
++is_idchar[i];
|
||
++is_idchar['_'];
|
||
++is_idstart['_'];
|
||
#if DOLLARS_IN_IDENTIFIERS
|
||
++is_idchar['$'];
|
||
++is_idstart['$'];
|
||
#endif
|
||
|
||
/* horizontal space table */
|
||
++is_hor_space[' '];
|
||
++is_hor_space['\t'];
|
||
}
|
||
|
||
error (msg)
|
||
{
|
||
printf ("error: %s\n", msg);
|
||
}
|
||
|
||
warning (msg)
|
||
{
|
||
printf ("warning: %s\n", msg);
|
||
}
|
||
|
||
struct hashnode *
|
||
lookup (name, len, hash)
|
||
char *name;
|
||
int len;
|
||
int hash;
|
||
{
|
||
return (DEFAULT_SIGNED_CHAR) ? 0 : ((struct hashnode *) -1);
|
||
}
|
||
#endif
|