/* $NetBSD: cond.c,v 1.60 2009/11/06 19:44:06 dsl Exp $ */ /* * Copyright (c) 1988, 1989, 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Adam de Boor. * * 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. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. */ /* * Copyright (c) 1988, 1989 by Adam de Boor * Copyright (c) 1989 by Berkeley Softworks * All rights reserved. * * This code is derived from software contributed to Berkeley by * Adam de Boor. * * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. */ #ifndef MAKE_NATIVE static char rcsid[] = "$NetBSD: cond.c,v 1.60 2009/11/06 19:44:06 dsl Exp $"; #else #include #ifndef lint #if 0 static char sccsid[] = "@(#)cond.c 8.2 (Berkeley) 1/2/94"; #else __RCSID("$NetBSD: cond.c,v 1.60 2009/11/06 19:44:06 dsl Exp $"); #endif #endif /* not lint */ #endif /*- * cond.c -- * Functions to handle conditionals in a makefile. * * Interface: * Cond_Eval Evaluate the conditional in the passed line. * */ #include #include /* For strtoul() error checking */ #include "make.h" #include "hash.h" #include "dir.h" #include "buf.h" /* * The parsing of conditional expressions is based on this grammar: * E -> F || E * E -> F * F -> T && F * F -> T * T -> defined(variable) * T -> make(target) * T -> exists(file) * T -> empty(varspec) * T -> target(name) * T -> commands(name) * T -> symbol * T -> $(varspec) op value * T -> $(varspec) == "string" * T -> $(varspec) != "string" * T -> "string" * T -> ( E ) * T -> ! T * op -> == | != | > | < | >= | <= * * 'symbol' is some other symbol to which the default function (condDefProc) * is applied. * * Tokens are scanned from the 'condExpr' string. The scanner (CondToken) * will return TOK_AND for '&' and '&&', TOK_OR for '|' and '||', * TOK_NOT for '!', TOK_LPAREN for '(', TOK_RPAREN for ')' and will evaluate * the other terminal symbols, using either the default function or the * function given in the terminal, and return the result as either TOK_TRUE * or TOK_FALSE. * * TOK_FALSE is 0 and TOK_TRUE 1 so we can directly assign C comparisons. * * All Non-Terminal functions (CondE, CondF and CondT) return TOK_ERROR on * error. */ typedef enum { TOK_FALSE = 0, TOK_TRUE = 1, TOK_AND, TOK_OR, TOK_NOT, TOK_LPAREN, TOK_RPAREN, TOK_EOF, TOK_NONE, TOK_ERROR } Token; /*- * Structures to handle elegantly the different forms of #if's. The * last two fields are stored in condInvert and condDefProc, respectively. */ static void CondPushBack(Token); static int CondGetArg(char **, char **, const char *); static Boolean CondDoDefined(int, const char *); static int CondStrMatch(const void *, const void *); static Boolean CondDoMake(int, const char *); static Boolean CondDoExists(int, const char *); static Boolean CondDoTarget(int, const char *); static Boolean CondDoCommands(int, const char *); static Boolean CondCvtArg(char *, double *); static Token CondToken(Boolean); static Token CondT(Boolean); static Token CondF(Boolean); static Token CondE(Boolean); static int do_Cond_EvalExpression(Boolean *); static const struct If { const char *form; /* Form of if */ int formlen; /* Length of form */ Boolean doNot; /* TRUE if default function should be negated */ Boolean (*defProc)(int, const char *); /* Default function to apply */ } ifs[] = { { "def", 3, FALSE, CondDoDefined }, { "ndef", 4, TRUE, CondDoDefined }, { "make", 4, FALSE, CondDoMake }, { "nmake", 5, TRUE, CondDoMake }, { "", 0, FALSE, CondDoDefined }, { NULL, 0, FALSE, NULL } }; static const struct If *if_info; /* Info for current statement */ static char *condExpr; /* The expression to parse */ static Token condPushBack=TOK_NONE; /* Single push-back token used in * parsing */ static unsigned int cond_depth = 0; /* current .if nesting level */ static unsigned int cond_min_depth = 0; /* depth at makefile open */ static int istoken(const char *str, const char *tok, size_t len) { return strncmp(str, tok, len) == 0 && !isalpha((unsigned char)str[len]); } /*- *----------------------------------------------------------------------- * CondPushBack -- * Push back the most recent token read. We only need one level of * this, so the thing is just stored in 'condPushback'. * * Input: * t Token to push back into the "stream" * * Results: * None. * * Side Effects: * condPushback is overwritten. * *----------------------------------------------------------------------- */ static void CondPushBack(Token t) { condPushBack = t; } /*- *----------------------------------------------------------------------- * CondGetArg -- * Find the argument of a built-in function. * * Input: * parens TRUE if arg should be bounded by parens * * Results: * The length of the argument and the address of the argument. * * Side Effects: * The pointer is set to point to the closing parenthesis of the * function call. * *----------------------------------------------------------------------- */ static int CondGetArg(char **linePtr, char **argPtr, const char *func) { char *cp; int argLen; Buffer buf; int paren_depth; char ch; cp = *linePtr; if (func != NULL) /* Skip opening '(' - verfied by caller */ cp++; if (*cp == '\0') { /* * No arguments whatsoever. Because 'make' and 'defined' aren't really * "reserved words", we don't print a message. I think this is better * than hitting the user with a warning message every time s/he uses * the word 'make' or 'defined' at the beginning of a symbol... */ *argPtr = NULL; return (0); } while (*cp == ' ' || *cp == '\t') { cp++; } /* * Create a buffer for the argument and start it out at 16 characters * long. Why 16? Why not? */ Buf_Init(&buf, 16); paren_depth = 0; for (;;) { ch = *cp; if (ch == 0 || ch == ' ' || ch == '\t') break; if ((ch == '&' || ch == '|') && paren_depth == 0) break; if (*cp == '$') { /* * Parse the variable spec and install it as part of the argument * if it's valid. We tell Var_Parse to complain on an undefined * variable, so we don't do it too. Nor do we return an error, * though perhaps we should... */ char *cp2; int len; void *freeIt; cp2 = Var_Parse(cp, VAR_CMD, TRUE, &len, &freeIt); Buf_AddBytes(&buf, strlen(cp2), cp2); if (freeIt) free(freeIt); cp += len; continue; } if (ch == '(') paren_depth++; else if (ch == ')' && --paren_depth < 0) break; Buf_AddByte(&buf, *cp); cp++; } *argPtr = Buf_GetAll(&buf, &argLen); Buf_Destroy(&buf, FALSE); while (*cp == ' ' || *cp == '\t') { cp++; } if (func != NULL && *cp++ != ')') { Parse_Error(PARSE_WARNING, "Missing closing parenthesis for %s()", func); return (0); } *linePtr = cp; return (argLen); } /*- *----------------------------------------------------------------------- * CondDoDefined -- * Handle the 'defined' function for conditionals. * * Results: * TRUE if the given variable is defined. * * Side Effects: * None. * *----------------------------------------------------------------------- */ static Boolean CondDoDefined(int argLen, const char *arg) { char *p1; Boolean result; if (Var_Value(arg, VAR_CMD, &p1) != NULL) { result = TRUE; } else { result = FALSE; } if (p1) free(p1); return (result); } /*- *----------------------------------------------------------------------- * CondStrMatch -- * Front-end for Str_Match so it returns 0 on match and non-zero * on mismatch. Callback function for CondDoMake via Lst_Find * * Results: * 0 if string matches pattern * * Side Effects: * None * *----------------------------------------------------------------------- */ static int CondStrMatch(const void *string, const void *pattern) { return(!Str_Match(string, pattern)); } /*- *----------------------------------------------------------------------- * CondDoMake -- * Handle the 'make' function for conditionals. * * Results: * TRUE if the given target is being made. * * Side Effects: * None. * *----------------------------------------------------------------------- */ static Boolean CondDoMake(int argLen, const char *arg) { return Lst_Find(create, arg, CondStrMatch) != NULL; } /*- *----------------------------------------------------------------------- * CondDoExists -- * See if the given file exists. * * Results: * TRUE if the file exists and FALSE if it does not. * * Side Effects: * None. * *----------------------------------------------------------------------- */ static Boolean CondDoExists(int argLen, const char *arg) { Boolean result; char *path; path = Dir_FindFile(arg, dirSearchPath); if (path != NULL) { result = TRUE; free(path); } else { result = FALSE; } if (DEBUG(COND)) { fprintf(debug_file, "exists(%s) result is \"%s\"\n", arg, path ? path : ""); } return (result); } /*- *----------------------------------------------------------------------- * CondDoTarget -- * See if the given node exists and is an actual target. * * Results: * TRUE if the node exists as a target and FALSE if it does not. * * Side Effects: * None. * *----------------------------------------------------------------------- */ static Boolean CondDoTarget(int argLen, const char *arg) { GNode *gn; gn = Targ_FindNode(arg, TARG_NOCREATE); return (gn != NULL) && !OP_NOP(gn->type); } /*- *----------------------------------------------------------------------- * CondDoCommands -- * See if the given node exists and is an actual target with commands * associated with it. * * Results: * TRUE if the node exists as a target and has commands associated with * it and FALSE if it does not. * * Side Effects: * None. * *----------------------------------------------------------------------- */ static Boolean CondDoCommands(int argLen, const char *arg) { GNode *gn; gn = Targ_FindNode(arg, TARG_NOCREATE); return (gn != NULL) && !OP_NOP(gn->type) && !Lst_IsEmpty(gn->commands); } /*- *----------------------------------------------------------------------- * CondCvtArg -- * Convert the given number into a double. * We try a base 10 or 16 integer conversion first, if that fails * then we try a floating point conversion instead. * * Results: * Sets 'value' to double value of string. * Returns 'true' if the convertion suceeded * *----------------------------------------------------------------------- */ static Boolean CondCvtArg(char *str, double *value) { char *eptr, ech; unsigned long l_val; double d_val; errno = 0; l_val = strtoul(str, &eptr, str[1] == 'x' ? 16 : 10); ech = *eptr; if (ech == 0 && errno != ERANGE) { d_val = str[0] == '-' ? -(double)-l_val : (double)l_val; } else { if (ech != 0 && ech != '.' && ech != 'e' && ech != 'E') return FALSE; d_val = strtod(str, &eptr); if (*eptr) return FALSE; } *value = d_val; return TRUE; } /*- *----------------------------------------------------------------------- * CondGetString -- * Get a string from a variable reference or an optionally quoted * string. This is called for the lhs and rhs of string compares. * * Results: * Sets freeIt if needed, * Sets quoted if string was quoted, * Returns NULL on error, * else returns string - absent any quotes. * * Side Effects: * Moves condExpr to end of this token. * * *----------------------------------------------------------------------- */ /* coverity:[+alloc : arg-*2] */ static char * CondGetString(Boolean doEval, Boolean *quoted, void **freeIt) { Buffer buf; char *cp; char *str; int len; int qt; char *start; Buf_Init(&buf, 0); str = NULL; *freeIt = NULL; *quoted = qt = *condExpr == '"' ? 1 : 0; if (qt) condExpr++; for (start = condExpr; *condExpr && str == NULL; condExpr++) { switch (*condExpr) { case '\\': if (condExpr[1] != '\0') { condExpr++; Buf_AddByte(&buf, *condExpr); } break; case '"': if (qt) { condExpr++; /* we don't want the quotes */ goto got_str; } else Buf_AddByte(&buf, *condExpr); /* likely? */ break; case ')': case '!': case '=': case '>': case '<': case ' ': case '\t': if (!qt) goto got_str; else Buf_AddByte(&buf, *condExpr); break; case '$': /* if we are in quotes, then an undefined variable is ok */ str = Var_Parse(condExpr, VAR_CMD, (qt ? 0 : doEval), &len, freeIt); if (str == var_Error) { if (*freeIt) { free(*freeIt); *freeIt = NULL; } /* * Even if !doEval, we still report syntax errors, which * is what getting var_Error back with !doEval means. */ str = NULL; goto cleanup; } condExpr += len; /* * If the '$' was first char (no quotes), and we are * followed by space, the operator or end of expression, * we are done. */ if ((condExpr == start + len) && (*condExpr == '\0' || isspace((unsigned char) *condExpr) || strchr("!=><)", *condExpr))) { goto cleanup; } /* * Nope, we better copy str to buf */ for (cp = str; *cp; cp++) { Buf_AddByte(&buf, *cp); } if (*freeIt) { free(*freeIt); *freeIt = NULL; } str = NULL; /* not finished yet */ condExpr--; /* don't skip over next char */ break; default: Buf_AddByte(&buf, *condExpr); break; } } got_str: str = Buf_GetAll(&buf, NULL); *freeIt = str; cleanup: Buf_Destroy(&buf, FALSE); return str; } /*- *----------------------------------------------------------------------- * CondToken -- * Return the next token from the input. * * Results: * A Token for the next lexical token in the stream. * * Side Effects: * condPushback will be set back to TOK_NONE if it is used. * *----------------------------------------------------------------------- */ static Token compare_expression(Boolean doEval) { Token t; char *lhs; char *rhs; char *op; void *lhsFree; void *rhsFree; Boolean lhsQuoted; Boolean rhsQuoted; double left, right; t = TOK_ERROR; rhs = NULL; lhsFree = rhsFree = FALSE; lhsQuoted = rhsQuoted = FALSE; /* * Parse the variable spec and skip over it, saving its * value in lhs. */ lhs = CondGetString(doEval, &lhsQuoted, &lhsFree); if (!lhs) goto done; /* * Skip whitespace to get to the operator */ while (isspace((unsigned char) *condExpr)) condExpr++; /* * Make sure the operator is a valid one. If it isn't a * known relational operator, pretend we got a * != 0 comparison. */ op = condExpr; switch (*condExpr) { case '!': case '=': case '<': case '>': if (condExpr[1] == '=') { condExpr += 2; } else { condExpr += 1; } break; default: if (!doEval) { t = TOK_FALSE; goto done; } /* For .ifxxx "..." check for non-empty string. */ if (lhsQuoted) { t = lhs[0] != 0; goto done; } /* For .ifxxx compare against zero */ if (CondCvtArg(lhs, &left)) { t = left != 0.0; goto done; } /* For .if ${...} check for non-empty string (defProc is ifdef). */ if (if_info->form[0] == 0) { t = lhs[0] != 0; goto done; } /* Otherwise action default test ... */ t = if_info->defProc(strlen(lhs), lhs) != if_info->doNot; goto done; } while (isspace((unsigned char)*condExpr)) condExpr++; if (*condExpr == '\0') { Parse_Error(PARSE_WARNING, "Missing right-hand-side of operator"); goto done; } rhs = CondGetString(doEval, &rhsQuoted, &rhsFree); if (!rhs) goto done; if (rhsQuoted || lhsQuoted) { do_string_compare: if (((*op != '!') && (*op != '=')) || (op[1] != '=')) { Parse_Error(PARSE_WARNING, "String comparison operator should be either == or !="); goto done; } if (DEBUG(COND)) { fprintf(debug_file, "lhs = \"%s\", rhs = \"%s\", op = %.2s\n", lhs, rhs, op); } /* * Null-terminate rhs and perform the comparison. * t is set to the result. */ if (*op == '=') { t = strcmp(lhs, rhs) == 0; } else { t = strcmp(lhs, rhs) != 0; } } else { /* * rhs is either a float or an integer. Convert both the * lhs and the rhs to a double and compare the two. */ if (!CondCvtArg(lhs, &left) || !CondCvtArg(rhs, &right)) goto do_string_compare; if (DEBUG(COND)) { fprintf(debug_file, "left = %f, right = %f, op = %.2s\n", left, right, op); } switch(op[0]) { case '!': if (op[1] != '=') { Parse_Error(PARSE_WARNING, "Unknown operator"); goto done; } t = (left != right); break; case '=': if (op[1] != '=') { Parse_Error(PARSE_WARNING, "Unknown operator"); goto done; } t = (left == right); break; case '<': if (op[1] == '=') { t = (left <= right); } else { t = (left < right); } break; case '>': if (op[1] == '=') { t = (left >= right); } else { t = (left > right); } break; } } done: if (lhsFree) free(lhsFree); if (rhsFree) free(rhsFree); return t; } static int get_mpt_arg(char **linePtr, char **argPtr, const char *func) { /* * Use Var_Parse to parse the spec in parens and return * TOK_TRUE if the resulting string is empty. */ int length; void *freeIt; char *val; char *cp = *linePtr; /* We do all the work here and return the result as the length */ *argPtr = NULL; val = Var_Parse(cp - 1, VAR_CMD, FALSE, &length, &freeIt); /* * Advance *linePtr to beyond the closing ). Note that * we subtract one because 'length' is calculated from 'cp - 1'. */ *linePtr = cp - 1 + length; if (val == var_Error) { free(freeIt); return -1; } /* A variable is empty when it just contains spaces... 4/15/92, christos */ while (isspace(*(unsigned char *)val)) val++; /* * For consistency with the other functions we can't generate the * true/false here. */ length = *val ? 2 : 1; if (freeIt) free(freeIt); return length; } static Boolean CondDoEmpty(int arglen, const char *arg) { return arglen == 1; } static Token compare_function(Boolean doEval) { static const struct fn_def { const char *fn_name; int fn_name_len; int (*fn_getarg)(char **, char **, const char *); Boolean (*fn_proc)(int, const char *); } fn_defs[] = { { "defined", 7, CondGetArg, CondDoDefined }, { "make", 4, CondGetArg, CondDoMake }, { "exists", 6, CondGetArg, CondDoExists }, { "empty", 5, get_mpt_arg, CondDoEmpty }, { "target", 6, CondGetArg, CondDoTarget }, { "commands", 8, CondGetArg, CondDoCommands }, { NULL, 0, NULL, NULL }, }; const struct fn_def *fn_def; Token t; char *arg = NULL; int arglen; char *cp = condExpr; char *cp1; for (fn_def = fn_defs; fn_def->fn_name != NULL; fn_def++) { if (!istoken(cp, fn_def->fn_name, fn_def->fn_name_len)) continue; cp += fn_def->fn_name_len; /* There can only be whitespace before the '(' */ while (isspace(*(unsigned char *)cp)) cp++; if (*cp != '(') break; arglen = fn_def->fn_getarg(&cp, &arg, fn_def->fn_name); if (arglen <= 0) { condExpr = cp; return arglen < 0 ? TOK_ERROR : TOK_FALSE; } /* Evaluate the argument using the required function. */ t = !doEval || fn_def->fn_proc(arglen, arg); if (arg) free(arg); condExpr = cp; return t; } /* Push anything numeric through the compare expression */ cp = condExpr; if (isdigit((unsigned char)cp[0]) || strchr("+-", cp[0])) return compare_expression(doEval); /* * Most likely we have a naked token to apply the default function to. * However ".if a == b" gets here when the "a" is unquoted and doesn't * start with a '$'. This surprises people. * If what follows the function argument is a '=' or '!' then the syntax * would be invalid if we did "defined(a)" - so instead treat as an * expression. */ arglen = CondGetArg(&cp, &arg, NULL); for (cp1 = cp; isspace(*(unsigned char *)cp1); cp1++) continue; if (*cp1 == '=' || *cp1 == '!') return compare_expression(doEval); condExpr = cp; /* * Evaluate the argument using the default function. * This path always treats .if as .ifdef. To get here the character * after .if must have been taken literally, so the argument cannot * be empty - even if it contained a variable expansion. */ t = !doEval || if_info->defProc(arglen, arg) != if_info->doNot; if (arg) free(arg); return t; } static Token CondToken(Boolean doEval) { Token t; t = condPushBack; if (t != TOK_NONE) { condPushBack = TOK_NONE; return t; } while (*condExpr == ' ' || *condExpr == '\t') { condExpr++; } switch (*condExpr) { case '(': condExpr++; return TOK_LPAREN; case ')': condExpr++; return TOK_RPAREN; case '|': if (condExpr[1] == '|') { condExpr++; } condExpr++; return TOK_OR; case '&': if (condExpr[1] == '&') { condExpr++; } condExpr++; return TOK_AND; case '!': condExpr++; return TOK_NOT; case '#': case '\n': case '\0': return TOK_EOF; case '"': case '$': return compare_expression(doEval); default: return compare_function(doEval); } } /*- *----------------------------------------------------------------------- * CondT -- * Parse a single term in the expression. This consists of a terminal * symbol or TOK_NOT and a terminal symbol (not including the binary * operators): * T -> defined(variable) | make(target) | exists(file) | symbol * T -> ! T | ( E ) * * Results: * TOK_TRUE, TOK_FALSE or TOK_ERROR. * * Side Effects: * Tokens are consumed. * *----------------------------------------------------------------------- */ static Token CondT(Boolean doEval) { Token t; t = CondToken(doEval); if (t == TOK_EOF) { /* * If we reached the end of the expression, the expression * is malformed... */ t = TOK_ERROR; } else if (t == TOK_LPAREN) { /* * T -> ( E ) */ t = CondE(doEval); if (t != TOK_ERROR) { if (CondToken(doEval) != TOK_RPAREN) { t = TOK_ERROR; } } } else if (t == TOK_NOT) { t = CondT(doEval); if (t == TOK_TRUE) { t = TOK_FALSE; } else if (t == TOK_FALSE) { t = TOK_TRUE; } } return (t); } /*- *----------------------------------------------------------------------- * CondF -- * Parse a conjunctive factor (nice name, wot?) * F -> T && F | T * * Results: * TOK_TRUE, TOK_FALSE or TOK_ERROR * * Side Effects: * Tokens are consumed. * *----------------------------------------------------------------------- */ static Token CondF(Boolean doEval) { Token l, o; l = CondT(doEval); if (l != TOK_ERROR) { o = CondToken(doEval); if (o == TOK_AND) { /* * F -> T && F * * If T is TOK_FALSE, the whole thing will be TOK_FALSE, but we have to * parse the r.h.s. anyway (to throw it away). * If T is TOK_TRUE, the result is the r.h.s., be it an TOK_ERROR or no. */ if (l == TOK_TRUE) { l = CondF(doEval); } else { (void)CondF(FALSE); } } else { /* * F -> T */ CondPushBack(o); } } return (l); } /*- *----------------------------------------------------------------------- * CondE -- * Main expression production. * E -> F || E | F * * Results: * TOK_TRUE, TOK_FALSE or TOK_ERROR. * * Side Effects: * Tokens are, of course, consumed. * *----------------------------------------------------------------------- */ static Token CondE(Boolean doEval) { Token l, o; l = CondF(doEval); if (l != TOK_ERROR) { o = CondToken(doEval); if (o == TOK_OR) { /* * E -> F || E * * A similar thing occurs for ||, except that here we make sure * the l.h.s. is TOK_FALSE before we bother to evaluate the r.h.s. * Once again, if l is TOK_FALSE, the result is the r.h.s. and once * again if l is TOK_TRUE, we parse the r.h.s. to throw it away. */ if (l == TOK_FALSE) { l = CondE(doEval); } else { (void)CondE(FALSE); } } else { /* * E -> F */ CondPushBack(o); } } return (l); } /*- *----------------------------------------------------------------------- * Cond_EvalExpression -- * Evaluate an expression in the passed line. The expression * consists of &&, ||, !, make(target), defined(variable) * and parenthetical groupings thereof. * * Results: * COND_PARSE if the condition was valid grammatically * COND_INVALID if not a valid conditional. * * (*value) is set to the boolean value of the condition * * Side Effects: * None. * *----------------------------------------------------------------------- */ int Cond_EvalExpression(const struct If *info, char *line, Boolean *value, int eprint) { static const struct If *dflt_info; const struct If *sv_if_info = if_info; char *sv_condExpr = condExpr; Token sv_condPushBack = condPushBack; int rval; while (*line == ' ' || *line == '\t') line++; if (info == NULL && (info = dflt_info) == NULL) { /* Scan for the entry for .if - it can't be first */ for (info = ifs; ; info++) if (info->form[0] == 0) break; dflt_info = info; } if_info = info != NULL ? info : ifs + 4; condExpr = line; condPushBack = TOK_NONE; rval = do_Cond_EvalExpression(value); if (rval == COND_INVALID && eprint) Parse_Error(PARSE_FATAL, "Malformed conditional (%s)", line); if_info = sv_if_info; condExpr = sv_condExpr; condPushBack = sv_condPushBack; return rval; } static int do_Cond_EvalExpression(Boolean *value) { switch (CondE(TRUE)) { case TOK_TRUE: if (CondToken(TRUE) == TOK_EOF) { *value = TRUE; return COND_PARSE; } break; case TOK_FALSE: if (CondToken(TRUE) == TOK_EOF) { *value = FALSE; return COND_PARSE; } break; default: case TOK_ERROR: break; } return COND_INVALID; } /*- *----------------------------------------------------------------------- * Cond_Eval -- * Evaluate the conditional in the passed line. The line * looks like this: * . * where is any of if, ifmake, ifnmake, ifdef, * ifndef, elif, elifmake, elifnmake, elifdef, elifndef * and consists of &&, ||, !, make(target), defined(variable) * and parenthetical groupings thereof. * * Input: * line Line to parse * * Results: * COND_PARSE if should parse lines after the conditional * COND_SKIP if should skip lines after the conditional * COND_INVALID if not a valid conditional. * * Side Effects: * None. * * Note that the states IF_ACTIVE and ELSE_ACTIVE are only different in order * to detect splurious .else lines (as are SKIP_TO_ELSE and SKIP_TO_ENDIF) * otherwise .else could be treated as '.elif 1'. * *----------------------------------------------------------------------- */ int Cond_Eval(char *line) { #define MAXIF 64 /* maximum depth of .if'ing */ enum if_states { IF_ACTIVE, /* .if or .elif part active */ ELSE_ACTIVE, /* .else part active */ SEARCH_FOR_ELIF, /* searching for .elif/else to execute */ SKIP_TO_ELSE, /* has been true, but not seen '.else' */ SKIP_TO_ENDIF /* nothing else to execute */ }; static enum if_states cond_state[MAXIF + 1] = { IF_ACTIVE }; const struct If *ifp; Boolean isElif; Boolean value; int level; /* Level at which to report errors. */ enum if_states state; level = PARSE_FATAL; /* skip leading character (the '.') and any whitespace */ for (line++; *line == ' ' || *line == '\t'; line++) continue; /* Find what type of if we're dealing with. */ if (line[0] == 'e') { if (line[1] != 'l') { if (!istoken(line + 1, "ndif", 4)) return COND_INVALID; /* End of conditional section */ if (cond_depth == cond_min_depth) { Parse_Error(level, "if-less endif"); return COND_PARSE; } /* Return state for previous conditional */ cond_depth--; if (cond_depth > MAXIF) return COND_SKIP; return cond_state[cond_depth] <= ELSE_ACTIVE ? COND_PARSE : COND_SKIP; } /* Quite likely this is 'else' or 'elif' */ line += 2; if (istoken(line, "se", 2)) { /* It is else... */ if (cond_depth == cond_min_depth) { Parse_Error(level, "if-less else"); return COND_PARSE; } if (cond_depth > MAXIF) return COND_SKIP; state = cond_state[cond_depth]; switch (state) { case SEARCH_FOR_ELIF: state = ELSE_ACTIVE; break; case ELSE_ACTIVE: case SKIP_TO_ENDIF: Parse_Error(PARSE_WARNING, "extra else"); /* FALLTHROUGH */ default: case IF_ACTIVE: case SKIP_TO_ELSE: state = SKIP_TO_ENDIF; break; } cond_state[cond_depth] = state; return state <= ELSE_ACTIVE ? COND_PARSE : COND_SKIP; } /* Assume for now it is an elif */ isElif = TRUE; } else isElif = FALSE; if (line[0] != 'i' || line[1] != 'f') /* Not an ifxxx or elifxxx line */ return COND_INVALID; /* * Figure out what sort of conditional it is -- what its default * function is, etc. -- by looking in the table of valid "ifs" */ line += 2; for (ifp = ifs; ; ifp++) { if (ifp->form == NULL) return COND_INVALID; if (istoken(ifp->form, line, ifp->formlen)) { line += ifp->formlen; break; } } /* Now we know what sort of 'if' it is... */ if (isElif) { if (cond_depth == cond_min_depth) { Parse_Error(level, "if-less elif"); return COND_PARSE; } if (cond_depth > MAXIF) /* Error reported when we saw the .if ... */ return COND_SKIP; state = cond_state[cond_depth]; if (state == SKIP_TO_ENDIF || state == ELSE_ACTIVE) { Parse_Error(PARSE_WARNING, "extra elif"); cond_state[cond_depth] = SKIP_TO_ENDIF; return COND_SKIP; } if (state != SEARCH_FOR_ELIF) { /* Either just finished the 'true' block, or already SKIP_TO_ELSE */ cond_state[cond_depth] = SKIP_TO_ELSE; return COND_SKIP; } } else { /* Normal .if */ if (cond_depth >= MAXIF) { cond_depth++; Parse_Error(PARSE_FATAL, "Too many nested if's. %d max.", MAXIF); return COND_SKIP; } state = cond_state[cond_depth]; cond_depth++; if (state > ELSE_ACTIVE) { /* If we aren't parsing the data, treat as always false */ cond_state[cond_depth] = SKIP_TO_ELSE; return COND_SKIP; } } /* And evaluate the conditional expresssion */ if (Cond_EvalExpression(ifp, line, &value, 1) == COND_INVALID) { /* Syntax error in conditional, error message already output. */ /* Skip everything to matching .endif */ cond_state[cond_depth] = SKIP_TO_ELSE; return COND_SKIP; } if (!value) { cond_state[cond_depth] = SEARCH_FOR_ELIF; return COND_SKIP; } cond_state[cond_depth] = IF_ACTIVE; return COND_PARSE; } /*- *----------------------------------------------------------------------- * Cond_End -- * Make sure everything's clean at the end of a makefile. * * Results: * None. * * Side Effects: * Parse_Error will be called if open conditionals are around. * *----------------------------------------------------------------------- */ void Cond_restore_depth(unsigned int saved_depth) { int open_conds = cond_depth - cond_min_depth; if (open_conds != 0 || saved_depth > cond_depth) { Parse_Error(PARSE_FATAL, "%d open conditional%s", open_conds, open_conds == 1 ? "" : "s"); cond_depth = cond_min_depth; } cond_min_depth = saved_depth; } unsigned int Cond_save_depth(void) { int depth = cond_min_depth; cond_min_depth = cond_depth; return depth; }