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* $XConsortium: ifparser.c,v 1.7 94/01/18 21:30:50 rws Exp $
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* Copyright 1992 Network Computing Devices, Inc.
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* Permission to use, copy, modify, and distribute this software and its
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* documentation for any purpose and without fee is hereby granted, provided
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* that the above copyright notice appear in all copies and that both that
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* copyright notice and this permission notice appear in supporting
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* documentation, and that the name of Network Computing Devices may not be
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* used in advertising or publicity pertaining to distribution of the software
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* without specific, written prior permission. Network Computing Devices makes
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* no representations about the suitability of this software for any purpose.
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* It is provided ``as is'' without express or implied warranty.
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* NETWORK COMPUTING DEVICES DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
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* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
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* IN NO EVENT SHALL NETWORK COMPUTING DEVICES BE LIABLE FOR ANY SPECIAL,
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* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
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* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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* PERFORMANCE OF THIS SOFTWARE.
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* Network Computing Devices, Inc.
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* Simple if statement processor
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* This module can be used to evaluate string representations of C language
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* if constructs. It accepts the following grammar:
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* | VALUE BINOP EXPRESSION
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* VALUE := '(' EXPRESSION ')'
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* | 'defined' '(' variable ')'
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* | 'defined' variable
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* | # variable '(' variable-list ')'
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* BINOP := '*' | '/' | '%'
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* | '<' | '>' | '<=' | '>='
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* The normal C order of precidence is supported.
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* External Entry Points:
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* ParseIfExpression parse a string for #if
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/****************************************************************************
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Internal Macros and Utilities for Parser
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****************************************************************************/
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#define DO(val) if (!(val)) return NULL
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#define CALLFUNC(ggg,fff) (*((ggg)->funcs.fff))
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#define SKIPSPACE(ccc) while (isspace(*ccc)) ccc++
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#define isvarfirstletter(ccc) (isalpha(ccc) || (ccc) == '_')
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parse_variable (g, cp, varp)
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if (!isvarfirstletter (*cp))
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return CALLFUNC(g, handle_error) (g, cp, "variable name");
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for (cp++; isalnum(*cp) || *cp == '_'; cp++) ;
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parse_number (g, cp, valp)
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return CALLFUNC(g, handle_error) (g, cp, "number");
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*valp = strtol(cp, &cp, 0);
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for (cp++; isdigit(*cp); cp++) ;
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parse_value (g, cp, valp)
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DO (cp = ParseIfExpression (g, cp + 1, valp));
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return CALLFUNC(g, handle_error) (g, cp, ")");
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return cp + 1; /* skip the right paren */
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DO (cp = parse_value (g, cp + 1, valp));
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DO (cp = parse_value (g, cp + 1, valp));
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DO (cp = parse_variable (g, cp + 1, &var));
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return CALLFUNC(g, handle_error) (g, cp, "(");
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DO (cp = parse_variable (g, cp + 1, &var));
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} while (*cp && *cp != ')');
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return CALLFUNC(g, handle_error) (g, cp, ")");
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if (strncmp (cp, "defined", 7) == 0 && !isalnum(cp[7])) {
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DO (cp = parse_variable (g, cp, &var));
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if (paren && *cp != ')')
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return CALLFUNC(g, handle_error) (g, cp, ")");
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*valp = (*(g->funcs.eval_defined)) (g, var, cp - var);
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return cp + paren; /* skip the right paren */
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DO (cp = parse_number (g, cp, valp));
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} else if (!isvarfirstletter(*cp))
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return CALLFUNC(g, handle_error) (g, cp, "variable or number");
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DO (cp = parse_variable (g, cp, &var));
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*valp = (*(g->funcs.eval_variable)) (g, var, cp - var);
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parse_product (g, cp, valp)
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DO (cp = parse_value (g, cp, valp));
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DO (cp = parse_product (g, cp + 1, &rightval));
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*valp = (*valp * rightval);
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DO (cp = parse_product (g, cp + 1, &rightval));
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*valp = (*valp / rightval);
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DO (cp = parse_product (g, cp + 1, &rightval));
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*valp = (*valp % rightval);
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parse_sum (g, cp, valp)
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DO (cp = parse_product (g, cp, valp));
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DO (cp = parse_sum (g, cp + 1, &rightval));
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*valp = (*valp + rightval);
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DO (cp = parse_sum (g, cp + 1, &rightval));
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*valp = (*valp - rightval);
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parse_shift (g, cp, valp)
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DO (cp = parse_sum (g, cp, valp));
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DO (cp = parse_shift (g, cp + 2, &rightval));
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*valp = (*valp << rightval);
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DO (cp = parse_shift (g, cp + 2, &rightval));
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*valp = (*valp >> rightval);
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parse_inequality (g, cp, valp)
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DO (cp = parse_shift (g, cp, valp));
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DO (cp = parse_inequality (g, cp + 2, &rightval));
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*valp = (*valp <= rightval);
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DO (cp = parse_inequality (g, cp + 1, &rightval));
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*valp = (*valp < rightval);
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DO (cp = parse_inequality (g, cp + 2, &rightval));
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*valp = (*valp >= rightval);
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DO (cp = parse_inequality (g, cp + 1, &rightval));
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*valp = (*valp > rightval);
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parse_equality (g, cp, valp)
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DO (cp = parse_inequality (g, cp, valp));
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DO (cp = parse_equality (g, cp + 1, &rightval));
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*valp = (*valp == rightval);
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DO (cp = parse_equality (g, cp + 2, &rightval));
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*valp = (*valp != rightval);
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parse_band (g, cp, valp)
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DO (cp = parse_equality (g, cp, valp));
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DO (cp = parse_band (g, cp + 1, &rightval));
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*valp = (*valp & rightval);
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parse_bor (g, cp, valp)
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DO (cp = parse_band (g, cp, valp));
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DO (cp = parse_bor (g, cp + 1, &rightval));
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*valp = (*valp | rightval);
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parse_land (g, cp, valp)
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DO (cp = parse_bor (g, cp, valp));
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return CALLFUNC(g, handle_error) (g, cp, "&&");
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DO (cp = parse_land (g, cp + 2, &rightval));
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*valp = (*valp && rightval);
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parse_lor (g, cp, valp)
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DO (cp = parse_land (g, cp, valp));
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return CALLFUNC(g, handle_error) (g, cp, "||");
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DO (cp = parse_lor (g, cp + 2, &rightval));
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*valp = (*valp || rightval);
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/****************************************************************************
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External Entry Points
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****************************************************************************/
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ParseIfExpression (g, cp, valp)
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return parse_lor (g, cp, valp);
added
removed
src/util/makedepend/ifparser.c
