/* * Copyright (c) 1988, 1989, 1990 The Regents of the University of California. * 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 lint #if 0 static char sccsid[] = "@(#)cond.c 8.2 (Berkeley) 1/2/94"; #else static const char rcsid[] = "$FreeBSD: src/usr.bin/make/cond.c,v 1.12 1999/09/11 13:08:01 hoek Exp $"; #endif #endif /* not lint */ /*- * cond.c -- * Functions to handle conditionals in a makefile. * * Interface: * Cond_Eval Evaluate the conditional in the passed line. * */ #include #include #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 -> symbol * T -> $(varspec) op value * T -> $(varspec) == "string" * T -> $(varspec) != "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 And for '&' and '&&', Or for '|' and '||', Not for '!', * LParen for '(', 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 True or False. * * All Non-Terminal functions (CondE, CondF and CondT) return Err on error. */ typedef enum { And, Or, Not, True, False, LParen, RParen, EndOfFile, None, Err } 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 __P((Token)); static int CondGetArg __P((char **, char **, char *, Boolean)); static Boolean CondDoDefined __P((int, char *)); static int CondStrMatch __P((ClientData, ClientData)); static Boolean CondDoMake __P((int, char *)); static Boolean CondDoExists __P((int, char *)); static Boolean CondDoTarget __P((int, char *)); static char * CondCvtArg __P((char *, double *)); static Token CondToken __P((Boolean)); static Token CondT __P((Boolean)); static Token CondF __P((Boolean)); static Token CondE __P((Boolean)); static struct If { char *form; /* Form of if */ int formlen; /* Length of form */ Boolean doNot; /* TRUE if default function should be negated */ Boolean (*defProc) __P((int, char *)); /* Default function to apply */ } ifs[] = { { "ifdef", 5, FALSE, CondDoDefined }, { "ifndef", 6, TRUE, CondDoDefined }, { "ifmake", 6, FALSE, CondDoMake }, { "ifnmake", 7, TRUE, CondDoMake }, { "if", 2, FALSE, CondDoDefined }, { NULL, 0, FALSE, NULL } }; static Boolean condInvert; /* Invert the default function */ static Boolean (*condDefProc) /* Default function to apply */ __P((int, char *)); static char *condExpr; /* The expression to parse */ static Token condPushBack=None; /* Single push-back token used in * parsing */ #define MAXIF 30 /* greatest depth of #if'ing */ static Boolean condStack[MAXIF]; /* Stack of conditionals's values */ static int condTop = MAXIF; /* Top-most conditional */ static int skipIfLevel=0; /* Depth of skipped conditionals */ static Boolean skipLine = FALSE; /* Whether the parse module is skipping * lines */ /*- *----------------------------------------------------------------------- * CondPushBack -- * Push back the most recent token read. We only need one level of * this, so the thing is just stored in 'condPushback'. * * Results: * None. * * Side Effects: * condPushback is overwritten. * *----------------------------------------------------------------------- */ static void CondPushBack (t) Token t; /* Token to push back into the "stream" */ { condPushBack = t; } /*- *----------------------------------------------------------------------- * CondGetArg -- * Find the argument of a built-in function. * * 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 (linePtr, argPtr, func, parens) char **linePtr; char **argPtr; char *func; Boolean parens; /* TRUE if arg should be bounded by parens */ { register char *cp; int argLen; register Buffer buf; cp = *linePtr; if (parens) { while (*cp != '(' && *cp != '\0') { cp++; } if (*cp == '(') { 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 = cp; 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 = Buf_Init(16); while ((strchr(" \t)&|", *cp) == (char *)NULL) && (*cp != '\0')) { 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; Boolean doFree; cp2 = Var_Parse(cp, VAR_CMD, TRUE, &len, &doFree); Buf_AddBytes(buf, strlen(cp2), (Byte *)cp2); if (doFree) { free(cp2); } cp += len; } else { Buf_AddByte(buf, (Byte)*cp); cp++; } } Buf_AddByte(buf, (Byte)'\0'); *argPtr = (char *)Buf_GetAll(buf, &argLen); Buf_Destroy(buf, FALSE); while (*cp == ' ' || *cp == '\t') { cp++; } if (parens && *cp != ')') { Parse_Error (PARSE_WARNING, "Missing closing parenthesis for %s()", func); return (0); } else if (parens) { /* * Advance pointer past close parenthesis. */ cp++; } *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 (argLen, arg) int argLen; char *arg; { char savec = arg[argLen]; char *p1; Boolean result; arg[argLen] = '\0'; if (Var_Value (arg, VAR_CMD, &p1) != (char *)NULL) { result = TRUE; } else { result = FALSE; } efree(p1); arg[argLen] = savec; 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(string, pattern) ClientData string; ClientData pattern; { return(!Str_Match((char *) string,(char *) pattern)); } /*- *----------------------------------------------------------------------- * CondDoMake -- * Handle the 'make' function for conditionals. * * Results: * TRUE if the given target is being made. * * Side Effects: * None. * *----------------------------------------------------------------------- */ static Boolean CondDoMake (argLen, arg) int argLen; char *arg; { char savec = arg[argLen]; Boolean result; arg[argLen] = '\0'; if (Lst_Find (create, (ClientData)arg, CondStrMatch) == NILLNODE) { result = FALSE; } else { result = TRUE; } arg[argLen] = savec; return (result); } /*- *----------------------------------------------------------------------- * 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 (argLen, arg) int argLen; char *arg; { char savec = arg[argLen]; Boolean result; char *path; arg[argLen] = '\0'; path = Dir_FindFile(arg, dirSearchPath); if (path != (char *)NULL) { result = TRUE; free(path); } else { result = FALSE; } arg[argLen] = savec; 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 (argLen, arg) int argLen; char *arg; { char savec = arg[argLen]; Boolean result; GNode *gn; arg[argLen] = '\0'; gn = Targ_FindNode(arg, TARG_NOCREATE); if ((gn != NILGNODE) && !OP_NOP(gn->type)) { result = TRUE; } else { result = FALSE; } arg[argLen] = savec; return (result); } /*- *----------------------------------------------------------------------- * CondCvtArg -- * Convert the given number into a double. If the number begins * with 0x, it is interpreted as a hexadecimal integer * and converted to a double from there. All other strings just have * strtod called on them. * * Results: * Sets 'value' to double value of string. * Returns address of the first character after the last valid * character of the converted number. * * Side Effects: * Can change 'value' even if string is not a valid number. * * *----------------------------------------------------------------------- */ static char * CondCvtArg(str, value) register char *str; double *value; { if ((*str == '0') && (str[1] == 'x')) { register long i; for (str += 2, i = 0; ; str++) { int x; if (isdigit((unsigned char) *str)) x = *str - '0'; else if (isxdigit((unsigned char) *str)) x = 10 + *str - isupper((unsigned char) *str) ? 'A' : 'a'; else { *value = (double) i; return str; } i = (i << 4) + x; } } else { char *eptr; *value = strtod(str, &eptr); return eptr; } } /*- *----------------------------------------------------------------------- * 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 None if it is used. * *----------------------------------------------------------------------- */ static Token CondToken(doEval) Boolean doEval; { Token t; if (condPushBack == None) { while (*condExpr == ' ' || *condExpr == '\t') { condExpr++; } switch (*condExpr) { case '(': t = LParen; condExpr++; break; case ')': t = RParen; condExpr++; break; case '|': if (condExpr[1] == '|') { condExpr++; } condExpr++; t = Or; break; case '&': if (condExpr[1] == '&') { condExpr++; } condExpr++; t = And; break; case '!': t = Not; condExpr++; break; case '\n': case '\0': t = EndOfFile; break; case '$': { char *lhs; char *rhs; char *op; int varSpecLen; Boolean doFree; /* * Parse the variable spec and skip over it, saving its * value in lhs. */ t = Err; lhs = Var_Parse(condExpr, VAR_CMD, doEval,&varSpecLen,&doFree); if (lhs == var_Error) { /* * Even if !doEval, we still report syntax errors, which * is what getting var_Error back with !doEval means. */ return(Err); } condExpr += varSpecLen; if (!isspace((unsigned char) *condExpr) && strchr("!=><", *condExpr) == NULL) { Buffer buf; char *cp; buf = Buf_Init(0); for (cp = lhs; *cp; cp++) Buf_AddByte(buf, (Byte)*cp); if (doFree) free(lhs); for (;*condExpr && !isspace((unsigned char) *condExpr); condExpr++) Buf_AddByte(buf, (Byte)*condExpr); Buf_AddByte(buf, (Byte)'\0'); lhs = (char *)Buf_GetAll(buf, &varSpecLen); Buf_Destroy(buf, FALSE); doFree = TRUE; } /* * 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: op = "!="; rhs = "0"; goto do_compare; } while (isspace((unsigned char) *condExpr)) { condExpr++; } if (*condExpr == '\0') { Parse_Error(PARSE_WARNING, "Missing right-hand-side of operator"); goto error; } rhs = condExpr; do_compare: if (*rhs == '"') { /* * Doing a string comparison. Only allow == and != for * operators. */ char *string; char *cp, *cp2; int qt; Buffer buf; do_string_compare: if (((*op != '!') && (*op != '=')) || (op[1] != '=')) { Parse_Error(PARSE_WARNING, "String comparison operator should be either == or !="); goto error; } buf = Buf_Init(0); qt = *rhs == '"' ? 1 : 0; for (cp = &rhs[qt]; ((qt && (*cp != '"')) || (!qt && strchr(" \t)", *cp) == NULL)) && (*cp != '\0'); cp++) { if ((*cp == '\\') && (cp[1] != '\0')) { /* * Backslash escapes things -- skip over next * character, if it exists. */ cp++; Buf_AddByte(buf, (Byte)*cp); } else if (*cp == '$') { int len; Boolean freeIt; cp2 = Var_Parse(cp, VAR_CMD, doEval,&len, &freeIt); if (cp2 != var_Error) { Buf_AddBytes(buf, strlen(cp2), (Byte *)cp2); if (freeIt) { free(cp2); } cp += len - 1; } else { Buf_AddByte(buf, (Byte)*cp); } } else { Buf_AddByte(buf, (Byte)*cp); } } Buf_AddByte(buf, (Byte)0); string = (char *)Buf_GetAll(buf, (int *)0); Buf_Destroy(buf, FALSE); if (DEBUG(COND)) { printf("lhs = \"%s\", rhs = \"%s\", op = %.2s\n", lhs, string, op); } /* * Null-terminate rhs and perform the comparison. * t is set to the result. */ if (*op == '=') { t = strcmp(lhs, string) ? False : True; } else { t = strcmp(lhs, string) ? True : False; } free(string); if (rhs == condExpr) { if (!qt && *cp == ')') condExpr = cp; else condExpr = cp + 1; } } else { /* * rhs is either a float or an integer. Convert both the * lhs and the rhs to a double and compare the two. */ double left, right; char *string; if (*CondCvtArg(lhs, &left) != '\0') goto do_string_compare; if (*rhs == '$') { int len; Boolean freeIt; string = Var_Parse(rhs, VAR_CMD, doEval,&len,&freeIt); if (string == var_Error) { right = 0.0; } else { if (*CondCvtArg(string, &right) != '\0') { if (freeIt) free(string); goto do_string_compare; } if (freeIt) free(string); if (rhs == condExpr) condExpr += len; } } else { char *c = CondCvtArg(rhs, &right); if (*c != '\0' && !isspace(*c)) goto do_string_compare; if (rhs == condExpr) { /* * Skip over the right-hand side */ while(!isspace((unsigned char) *condExpr) && (*condExpr != '\0')) { condExpr++; } } } if (DEBUG(COND)) { printf("left = %f, right = %f, op = %.2s\n", left, right, op); } switch(op[0]) { case '!': if (op[1] != '=') { Parse_Error(PARSE_WARNING, "Unknown operator"); goto error; } t = (left != right ? True : False); break; case '=': if (op[1] != '=') { Parse_Error(PARSE_WARNING, "Unknown operator"); goto error; } t = (left == right ? True : False); break; case '<': if (op[1] == '=') { t = (left <= right ? True : False); } else { t = (left < right ? True : False); } break; case '>': if (op[1] == '=') { t = (left >= right ? True : False); } else { t = (left > right ? True : False); } break; } } error: if (doFree) free(lhs); break; } default: { Boolean (*evalProc) __P((int, char *)); Boolean invert = FALSE; char *arg; int arglen; if (strncmp (condExpr, "defined", 7) == 0) { /* * Use CondDoDefined to evaluate the argument and * CondGetArg to extract the argument from the 'function * call'. */ evalProc = CondDoDefined; condExpr += 7; arglen = CondGetArg (&condExpr, &arg, "defined", TRUE); if (arglen == 0) { condExpr -= 7; goto use_default; } } else if (strncmp (condExpr, "make", 4) == 0) { /* * Use CondDoMake to evaluate the argument and * CondGetArg to extract the argument from the 'function * call'. */ evalProc = CondDoMake; condExpr += 4; arglen = CondGetArg (&condExpr, &arg, "make", TRUE); if (arglen == 0) { condExpr -= 4; goto use_default; } } else if (strncmp (condExpr, "exists", 6) == 0) { /* * Use CondDoExists to evaluate the argument and * CondGetArg to extract the argument from the * 'function call'. */ evalProc = CondDoExists; condExpr += 6; arglen = CondGetArg(&condExpr, &arg, "exists", TRUE); if (arglen == 0) { condExpr -= 6; goto use_default; } } else if (strncmp(condExpr, "empty", 5) == 0) { /* * Use Var_Parse to parse the spec in parens and return * True if the resulting string is empty. */ int length; Boolean doFree; char *val; condExpr += 5; for (arglen = 0; condExpr[arglen] != '(' && condExpr[arglen] != '\0'; arglen += 1) continue; if (condExpr[arglen] != '\0') { val = Var_Parse(&condExpr[arglen - 1], VAR_CMD, doEval, &length, &doFree); if (val == var_Error) { t = Err; } else { /* * A variable is empty when it just contains * spaces... 4/15/92, christos */ char *p; for (p = val; *p && isspace((unsigned char)*p); p++) continue; t = (*p == '\0') ? True : False; } if (doFree) { free(val); } /* * Advance condExpr to beyond the closing ). Note that * we subtract one from arglen + length b/c length * is calculated from condExpr[arglen - 1]. */ condExpr += arglen + length - 1; } else { condExpr -= 5; goto use_default; } break; } else if (strncmp (condExpr, "target", 6) == 0) { /* * Use CondDoTarget to evaluate the argument and * CondGetArg to extract the argument from the * 'function call'. */ evalProc = CondDoTarget; condExpr += 6; arglen = CondGetArg(&condExpr, &arg, "target", TRUE); if (arglen == 0) { condExpr -= 6; goto use_default; } } else { /* * The symbol is itself the argument to the default * function. We advance condExpr to the end of the symbol * by hand (the next whitespace, closing paren or * binary operator) and set to invert the evaluation * function if condInvert is TRUE. */ use_default: invert = condInvert; evalProc = condDefProc; arglen = CondGetArg(&condExpr, &arg, "", FALSE); } /* * Evaluate the argument using the set function. If invert * is TRUE, we invert the sense of the function. */ t = (!doEval || (* evalProc) (arglen, arg) ? (invert ? False : True) : (invert ? True : False)); free(arg); break; } } } else { t = condPushBack; condPushBack = None; } return (t); } /*- *----------------------------------------------------------------------- * CondT -- * Parse a single term in the expression. This consists of a terminal * symbol or Not and a terminal symbol (not including the binary * operators): * T -> defined(variable) | make(target) | exists(file) | symbol * T -> ! T | ( E ) * * Results: * True, False or Err. * * Side Effects: * Tokens are consumed. * *----------------------------------------------------------------------- */ static Token CondT(doEval) Boolean doEval; { Token t; t = CondToken(doEval); if (t == EndOfFile) { /* * If we reached the end of the expression, the expression * is malformed... */ t = Err; } else if (t == LParen) { /* * T -> ( E ) */ t = CondE(doEval); if (t != Err) { if (CondToken(doEval) != RParen) { t = Err; } } } else if (t == Not) { t = CondT(doEval); if (t == True) { t = False; } else if (t == False) { t = True; } } return (t); } /*- *----------------------------------------------------------------------- * CondF -- * Parse a conjunctive factor (nice name, wot?) * F -> T && F | T * * Results: * True, False or Err * * Side Effects: * Tokens are consumed. * *----------------------------------------------------------------------- */ static Token CondF(doEval) Boolean doEval; { Token l, o; l = CondT(doEval); if (l != Err) { o = CondToken(doEval); if (o == And) { /* * F -> T && F * * If T is False, the whole thing will be False, but we have to * parse the r.h.s. anyway (to throw it away). * If T is True, the result is the r.h.s., be it an Err or no. */ if (l == True) { l = CondF(doEval); } else { (void) CondF(FALSE); } } else { /* * F -> T */ CondPushBack (o); } } return (l); } /*- *----------------------------------------------------------------------- * CondE -- * Main expression production. * E -> F || E | F * * Results: * True, False or Err. * * Side Effects: * Tokens are, of course, consumed. * *----------------------------------------------------------------------- */ static Token CondE(doEval) Boolean doEval; { Token l, o; l = CondF(doEval); if (l != Err) { o = CondToken(doEval); if (o == Or) { /* * E -> F || E * * A similar thing occurs for ||, except that here we make sure * the l.h.s. is False before we bother to evaluate the r.h.s. * Once again, if l is False, the result is the r.h.s. and once * again if l is True, we parse the r.h.s. to throw it away. */ if (l == False) { l = CondE(doEval); } else { (void) CondE(FALSE); } } else { /* * E -> F */ CondPushBack (o); } } return (l); } /*- *----------------------------------------------------------------------- * 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. * * 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. * *----------------------------------------------------------------------- */ int Cond_Eval (line) char *line; /* Line to parse */ { struct If *ifp; Boolean isElse; Boolean value = FALSE; int level; /* Level at which to report errors. */ level = PARSE_FATAL; for (line++; *line == ' ' || *line == '\t'; line++) { continue; } /* * Find what type of if we're dealing with. The result is left * in ifp and isElse is set TRUE if it's an elif line. */ if (line[0] == 'e' && line[1] == 'l') { line += 2; isElse = TRUE; } else if (strncmp (line, "endif", 5) == 0) { /* * End of a conditional section. If skipIfLevel is non-zero, that * conditional was skipped, so lines following it should also be * skipped. Hence, we return COND_SKIP. Otherwise, the conditional * was read so succeeding lines should be parsed (think about it...) * so we return COND_PARSE, unless this endif isn't paired with * a decent if. */ if (skipIfLevel != 0) { skipIfLevel -= 1; return (COND_SKIP); } else { if (condTop == MAXIF) { Parse_Error (level, "if-less endif"); return (COND_INVALID); } else { skipLine = FALSE; condTop += 1; return (COND_PARSE); } } } else { isElse = FALSE; } /* * Figure out what sort of conditional it is -- what its default * function is, etc. -- by looking in the table of valid "ifs" */ for (ifp = ifs; ifp->form != (char *)0; ifp++) { if (strncmp (ifp->form, line, ifp->formlen) == 0) { break; } } if (ifp->form == (char *) 0) { /* * Nothing fit. If the first word on the line is actually * "else", it's a valid conditional whose value is the inverse * of the previous if we parsed. */ if (isElse && (line[0] == 's') && (line[1] == 'e')) { if (condTop == MAXIF) { Parse_Error (level, "if-less else"); return (COND_INVALID); } else if (skipIfLevel == 0) { value = !condStack[condTop]; } else { return (COND_SKIP); } } else { /* * Not a valid conditional type. No error... */ return (COND_INVALID); } } else { if (isElse) { if (condTop == MAXIF) { Parse_Error (level, "if-less elif"); return (COND_INVALID); } else if (skipIfLevel != 0) { /* * If skipping this conditional, just ignore the whole thing. * If we don't, the user might be employing a variable that's * undefined, for which there's an enclosing ifdef that * we're skipping... */ return(COND_SKIP); } } else if (skipLine) { /* * Don't even try to evaluate a conditional that's not an else if * we're skipping things... */ skipIfLevel += 1; return(COND_SKIP); } /* * Initialize file-global variables for parsing */ condDefProc = ifp->defProc; condInvert = ifp->doNot; line += ifp->formlen; while (*line == ' ' || *line == '\t') { line++; } condExpr = line; condPushBack = None; switch (CondE(TRUE)) { case True: if (CondToken(TRUE) == EndOfFile) { value = TRUE; break; } goto err; /*FALLTHRU*/ case False: if (CondToken(TRUE) == EndOfFile) { value = FALSE; break; } /*FALLTHRU*/ case Err: err: Parse_Error (level, "Malformed conditional (%s)", line); return (COND_INVALID); default: break; } } if (!isElse) { condTop -= 1; } else if ((skipIfLevel != 0) || condStack[condTop]) { /* * If this is an else-type conditional, it should only take effect * if its corresponding if was evaluated and FALSE. If its if was * TRUE or skipped, we return COND_SKIP (and start skipping in case * we weren't already), leaving the stack unmolested so later elif's * don't screw up... */ skipLine = TRUE; return (COND_SKIP); } if (condTop < 0) { /* * This is the one case where we can definitely proclaim a fatal * error. If we don't, we're hosed. */ Parse_Error (PARSE_FATAL, "Too many nested if's. %d max.", MAXIF); return (COND_INVALID); } else { condStack[condTop] = value; skipLine = !value; return (value ? COND_PARSE : COND_SKIP); } } /*- *----------------------------------------------------------------------- * 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_End() { if (condTop != MAXIF) { Parse_Error(PARSE_FATAL, "%d open conditional%s", MAXIF-condTop, MAXIF-condTop == 1 ? "" : "s"); } condTop = MAXIF; }