+++ /dev/null
-/* Parse C expressions for CCCP.
- Copyright (C) 1987, 2000, 2001 Free Software Foundation.
- Adapted from expread.y of GDB by Paul Rubin, July 1986.
- Adapted to ANSI C, Richard Stallman, Jan 1987
- Dusted off, polished, and adapted for use as traditional
- preprocessor only, Zack Weinberg, Jul 2000
-
-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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
-
-/* Parse a C expression from text in a string */
-
-%{
-#include "config.h"
-#include "system.h"
-#include "intl.h"
-#include "tradcpp.h"
-#include <setjmp.h>
-
- static int yylex PARAMS ((void));
- static void yyerror PARAMS ((const char *msgid)) ATTRIBUTE_NORETURN;
-
- static int parse_number PARAMS ((int));
- static int parse_escape PARAMS ((const char **));
-
- static int expression_value;
- static jmp_buf parse_return_error;
-
- /* During parsing of a C expression, the pointer to the next
- character is in this variable. */
-
- static const char *lexptr;
-%}
-
-%union {
- struct constant {long value; int unsignedp;} integer;
- int voidval;
- char *sval;
-}
-
-%type <integer> exp exp1 start
-%token <integer> INT CHAR
-%token <sval> 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 */
-\f
-%%
-
-start : exp1
- { expression_value = $1.value; }
- ;
-
-/* Expressions, including the comma operator. */
-exp1 : exp
- | exp1 ',' exp
- { $$ = $3; }
- ;
-
-/* Expressions, not including the comma operator. */
-exp : '-' exp %prec UNARY
- { $$.value = - $2.value;
- $$.unsignedp = $2.unsignedp; }
- | '!' exp %prec UNARY
- { $$.value = ! $2.value;
- $$.unsignedp = 0; }
- | '+' exp %prec UNARY
- { $$ = $2; }
- | '~' exp %prec UNARY
- { $$.value = ~ $2.value;
- $$.unsignedp = $2.unsignedp; }
- | '(' exp1 ')'
- { $$ = $2; }
- ;
-
-/* Binary operators in order of decreasing precedence. */
-exp : exp '*' exp
- { $$.unsignedp = $1.unsignedp || $3.unsignedp;
- if ($$.unsignedp)
- $$.value = (unsigned) $1.value * $3.value;
- else
- $$.value = $1.value * $3.value; }
- | exp '/' exp
- { if ($3.value == 0)
- {
- error ("division by zero in #if");
- $3.value = 1;
- }
- $$.unsignedp = $1.unsignedp || $3.unsignedp;
- if ($$.unsignedp)
- $$.value = (unsigned) $1.value / $3.value;
- else
- $$.value = $1.value / $3.value; }
- | exp '%' exp
- { if ($3.value == 0)
- {
- error ("division by zero in #if");
- $3.value = 1;
- }
- $$.unsignedp = $1.unsignedp || $3.unsignedp;
- if ($$.unsignedp)
- $$.value = (unsigned) $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;
- $$.unsignedp = $1.unsignedp || $3.unsignedp; }
- | exp LSH exp
- { $$.unsignedp = $1.unsignedp;
- if ($$.unsignedp)
- $$.value = (unsigned) $1.value << $3.value;
- else
- $$.value = $1.value << $3.value; }
- | exp RSH exp
- { $$.unsignedp = $1.unsignedp;
- if ($$.unsignedp)
- $$.value = (unsigned) $1.value >> $3.value;
- else
- $$.value = $1.value >> $3.value; }
- | exp EQUAL exp
- { $$.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)
- $$.value =
- (unsigned) $1.value <= (unsigned) $3.value;
- else
- $$.value = $1.value <= $3.value; }
- | exp GEQ exp
- { $$.unsignedp = 0;
- if ($1.unsignedp || $3.unsignedp)
- $$.value =
- (unsigned) $1.value >= (unsigned) $3.value;
- else
- $$.value = $1.value >= $3.value; }
- | exp '<' exp
- { $$.unsignedp = 0;
- if ($1.unsignedp || $3.unsignedp)
- $$.value =
- (unsigned) $1.value < (unsigned) $3.value;
- else
- $$.value = $1.value < $3.value; }
- | exp '>' exp
- { $$.unsignedp = 0;
- if ($1.unsignedp || $3.unsignedp)
- $$.value =
- (unsigned) $1.value > (unsigned) $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;
- $$.unsignedp = 0; }
- | '#' { $$.value =
- test_assertion ((unsigned char **) &lexptr); }
- ;
-%%
-\f
-/* 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 */
-
-static int
-parse_number (olen)
- int olen;
-{
- const char *p = lexptr;
- long n = 0;
- int c;
- int base = 10;
- int len = olen;
-
- 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;
- }
-
- /* Traditionally, all numbers are signed. However, we make it
- unsigned if requested with a suffix. */
- 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;
-
- while (len > 0) {
- c = *p++;
- len--;
- if (ISUPPER (c))
- c = TOLOWER (c);
-
- if (ISDIGIT (c)
- || (base == 16 && ISXDIGIT (c))) {
- n = (n * base) + hex_value (c);
- } else {
- /* `l' means long, and `u' means unsigned. */
- while (1) {
- if (c == 'l' || c == 'L')
- ;
- else if (c == 'u' || c == 'U')
- yylval.integer.unsignedp = 1;
- else
- break;
-
- if (len == 0)
- break;
- c = *p++;
- len--;
- }
- /* Don't look for any more digits after the suffixes. */
- break;
- }
- }
-
- if (len != 0) {
- yyerror ("invalid number in #if expression");
- return ERROR;
- }
-
- lexptr = p;
- yylval.integer.value = n;
- return INT;
-}
-
-struct token {
- const char *const operator;
- const int token;
-};
-
-#ifndef NULL
-#define NULL 0
-#endif
-
-static const struct token tokentab2[] = {
- {"&&", AND},
- {"||", OR},
- {"<<", LSH},
- {">>", RSH},
- {"==", EQUAL},
- {"!=", NOTEQUAL},
- {"<=", LEQ},
- {">=", GEQ},
- {NULL, ERROR}
-};
-
-/* Read one token, getting characters through lexptr. */
-
-static int
-yylex ()
-{
- int c;
- int namelen;
- const char *tokstart;
- const struct token *toktab;
-
- retry:
-
- tokstart = lexptr;
- c = *tokstart;
- /* See if it is a special token of length 2. */
- for (toktab = tokentab2; toktab->operator != NULL; toktab++)
- if (c == *toktab->operator && tokstart[1] == toktab->operator[1]) {
- lexptr += 2;
- return toktab->token;
- }
-
- switch (c) {
- case 0:
- return 0;
-
- case ' ':
- case '\t':
- case '\r':
- case '\n':
- lexptr++;
- goto retry;
-
- case '\'':
- lexptr++;
- c = *lexptr++;
- if (c == '\\')
- c = parse_escape (&lexptr);
-
- /* Sign-extend the constant if chars are signed on target machine. */
- {
- if (flag_signed_char == 0
- || ((c >> (CHAR_TYPE_SIZE - 1)) & 1) == 0)
- yylval.integer.value = c & ((1 << CHAR_TYPE_SIZE) - 1);
- else
- yylval.integer.value = c | ~((1 << CHAR_TYPE_SIZE) - 1);
- }
-
- yylval.integer.unsignedp = 0;
- c = *lexptr++;
- if (c != '\'') {
- yyerror ("invalid character constant in #if");
- return ERROR;
- }
-
- 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 '}':
- case ',':
- case '#':
- lexptr++;
- return c;
-
- case '"':
- yyerror ("double quoted strings not allowed in #if expressions");
- return ERROR;
- }
- if (ISDIGIT (c)) {
- /* It's a number */
- for (namelen = 0;
- c = tokstart[namelen], is_idchar (c) || c == '.';
- namelen++)
- ;
- return parse_number (namelen);
- }
-
- if (!is_idstart (c)) {
- yyerror ("invalid token in expression");
- return ERROR;
- }
-
- /* It is a name. See how long it is. */
-
- for (namelen = 0;
- is_idchar (tokstart[namelen]);
- namelen++)
- ;
-
- lexptr += 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. */
-
-static int
-parse_escape (string_ptr)
- const char **string_ptr;
-{
- int c = *(*string_ptr)++;
- switch (c)
- {
- case 'a':
- return TARGET_BELL;
- case 'b':
- return TARGET_BS;
- case 'e':
- 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 '^':
- c = *(*string_ptr)++;
- if (c == '\\')
- c = parse_escape (string_ptr);
- if (c == '?')
- return 0177;
- return (c & 0200) | (c & 037);
-
- case '0':
- case '1':
- case '2':
- case '3':
- case '4':
- case '5':
- case '6':
- case '7':
- {
- int i = c - '0';
- 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':
- {
- int i = 0;
- for (;;)
- {
- c = *(*string_ptr)++;
- if (hex_p (c))
- i = (i << 4) + hex_value (c);
- else
- {
- (*string_ptr)--;
- break;
- }
- }
- if ((i & ~((1 << BITS_PER_UNIT) - 1)) != 0)
- {
- i &= (1 << BITS_PER_UNIT) - 1;
- warning ("hex character constant does not fit in a byte");
- }
- return i;
- }
- default:
- return c;
- }
-}
-
-static void
-yyerror (msgid)
- const char *msgid;
-{
- error ("%s", _(msgid));
- longjmp (parse_return_error, 1);
-}
-\f
-/* 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)
- const 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 () */
-}
projects / msp430-gcc.git / blobdiff