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freebsd-nq/usr.bin/make/cond.c

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BSD 4.4 Lite Usr.bin Sources
1994-05-27 12:33:43 +00:00
/*
* Copyright (c) 1988, 1989, 1990, 1993
* The Regents of the University of California. All rights reserved.
* 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
static char sccsid[] = "@(#)cond.c 8.2 (Berkeley) 1/2/94";
#endif /* not lint */
/*-
* cond.c --
* Functions to handle conditionals in a makefile.
*
* Interface:
* Cond_Eval Evaluate the conditional in the passed line.
*
*/
#include <ctype.h>
#include <math.h>
#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 int CondGetArg __P((char **, char **, char *, Boolean));
static Boolean CondDoDefined __P((int, char *));
static int CondStrMatch __P((char *, char *));
static Boolean CondDoMake __P((int, char *));
static Boolean CondDoExists __P((int, char *));
static Boolean CondDoTarget __P((int, char *));
static Boolean 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)(); /* 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 },
{ (char *)0, 0, FALSE, (Boolean (*)())0 }
};
static Boolean condInvert; /* Invert the default function */
static Boolean (*condDefProc)(); /* Default function to apply */
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];
Boolean result;
arg[argLen] = '\0';
if (Var_Value (arg, VAR_CMD) != (char *)NULL) {
result = TRUE;
} else {
result = FALSE;
}
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)
char *string;
char *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 (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 true if the string was a valid number, false o.w.
*
* Side Effects:
* Can change 'value' even if string is not a valid number.
*
*
*-----------------------------------------------------------------------
*/
static Boolean
CondCvtArg(str, value)
register char *str;
double *value;
{
if ((*str == '0') && (str[1] == 'x')) {
register long i;
for (str += 2, i = 0; *str; 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
return FALSE;
i = (i << 4) + x;
}
*value = (double) i;
return TRUE;
}
else {
char *eptr;
*value = strtod(str, &eptr);
return *eptr == '\0';
}
}
/*-
*-----------------------------------------------------------------------
* 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(*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(*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(*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(*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))
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)) {
if (freeIt)
free(string);
goto do_string_compare;
}
if (freeIt)
free(string);
if (rhs == condExpr)
condExpr += len;
}
} else {
if (!CondCvtArg(rhs, &right))
goto do_string_compare;
if (rhs == condExpr) {
/*
* Skip over the right-hand side
*/
while(!isspace(*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)();
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)
{
/* void */ ;
}
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(*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:
* #<cond-type> <expr>
* where <cond-type> is any of if, ifmake, ifnmake, ifdef,
* ifndef, elif, elifmake, elifnmake, elifdef, elifndef
* and <expr> 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;
}
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