File: [cvs.NetBSD.org] / src / usr.bin / make / cond.c (download)
Revision 1.101, Thu Aug 27 19:15:35 2020 UTC (3 years, 7 months ago) by rillig
Branch: MAIN
Changes since 1.100: +4 -4
lines
make(1): migrate Lst_IsEmpty to Lst_IsEmptyS
|
/* $NetBSD: cond.c,v 1.101 2020/08/27 19:15:35 rillig 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 1.101 2020/08/27 19:15:35 rillig Exp $";
#else
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)cond.c 8.2 (Berkeley) 1/2/94";
#else
__RCSID("$NetBSD: cond.c,v 1.101 2020/08/27 19:15:35 rillig 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 <errno.h>
#include "make.h"
#include "dir.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 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;
static Token CondE(Boolean);
static CondEvalResult do_Cond_EvalExpression(Boolean *);
static const struct If *if_info; /* Info for current statement */
static const 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 */
/*
* Indicate when we should be strict about lhs of comparisons.
* TRUE when Cond_EvalExpression is called from Cond_Eval (.if etc)
* FALSE when Cond_EvalExpression is called from var.c:ApplyModifiers
* since lhs is already expanded and we cannot tell if
* it was a variable reference or not.
*/
static Boolean lhsStrict;
static int
istoken(const char *str, const char *tok, size_t len)
{
return strncmp(str, tok, len) == 0 && !isalpha((unsigned char)str[len]);
}
/* Push back the most recent token read. We only need one level of
* this, so the thing is just stored in 'condPushback'. */
static void
CondPushBack(Token t)
{
condPushBack = t;
}
/*-
* Parse the argument of a built-in function.
*
* Results:
* The length of the argument.
* *argPtr receives the argument as string.
* *linePtr is updated to point behind the ')' of the function call.
*/
static int
CondGetArg(Boolean doEval, const char **linePtr, char **argPtr,
const char *func)
{
const char *cp;
Buffer buf;
int paren_depth;
char ch;
size_t argLen;
cp = *linePtr;
if (func != NULL)
/* Skip opening '(' - verified 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...
*/
int len;
void *freeIt;
VarEvalFlags eflags = VARE_UNDEFERR | (doEval ? VARE_WANTRES : 0);
const char *cp2 = Var_Parse(cp, VAR_CMD, eflags, &len, &freeIt);
Buf_AddStr(&buf, cp2);
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;
}
/* Test whether the given variable is defined. */
static Boolean
CondDoDefined(int argLen MAKE_ATTR_UNUSED, const char *arg)
{
char *freeIt;
Boolean result = Var_Value(arg, VAR_CMD, &freeIt) != NULL;
bmake_free(freeIt);
return result;
}
/* Wrapper around Str_Match that returns 0 on match and non-zero
* on mismatch. Callback function for CondDoMake via Lst_Find. */
static int
CondFindStrMatch(const void *string, const void *pattern)
{
return !Str_Match(string, pattern);
}
/* See if the given target is being made. */
static Boolean
CondDoMake(int argLen MAKE_ATTR_UNUSED, const char *arg)
{
return Lst_Find(create, CondFindStrMatch, arg) != NULL;
}
/* See if the given file exists. */
static Boolean
CondDoExists(int argLen MAKE_ATTR_UNUSED, const char *arg)
{
Boolean result;
char *path;
path = Dir_FindFile(arg, dirSearchPath);
if (DEBUG(COND)) {
fprintf(debug_file, "exists(%s) result is \"%s\"\n",
arg, path ? path : "");
}
if (path != NULL) {
result = TRUE;
free(path);
} else {
result = FALSE;
}
return result;
}
/* See if the given node exists and is an actual target. */
static Boolean
CondDoTarget(int argLen MAKE_ATTR_UNUSED, const char *arg)
{
GNode *gn;
gn = Targ_FindNode(arg, TARG_NOCREATE);
return gn != NULL && !OP_NOP(gn->type);
}
/* See if the given node exists and is an actual target with commands
* associated with it. */
static Boolean
CondDoCommands(int argLen MAKE_ATTR_UNUSED, const char *arg)
{
GNode *gn;
gn = Targ_FindNode(arg, TARG_NOCREATE);
return gn != NULL && !OP_NOP(gn->type) && !Lst_IsEmptyS(gn->commands);
}
/*-
* 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 conversion succeeded.
*/
static Boolean
CondCvtArg(const char *str, double *value)
{
char *eptr, ech;
unsigned long l_val;
double d_val;
errno = 0;
if (!*str) {
*value = (double)0;
return TRUE;
}
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;
}
/*-
* Get a string from a variable reference or an optionally quoted
* string. This is called for the lhs and rhs of string compares.
*
* Results:
* Returns the string, absent any quotes, or NULL on error.
* Sets quoted if the string was quoted.
* Sets freeIt if needed.
*
* Side Effects:
* Moves condExpr past the end of this token.
*/
/* coverity:[+alloc : arg-*2] */
static const char *
CondGetString(Boolean doEval, Boolean *quoted, void **freeIt, Boolean strictLHS)
{
Buffer buf;
const char *cp;
const char *str;
int len;
Boolean qt;
const char *start;
VarEvalFlags eflags;
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 '$':
/* if we are in quotes, then an undefined variable is ok */
eflags = ((!qt && doEval) ? VARE_UNDEFERR : 0) |
(doEval ? VARE_WANTRES : 0);
str = Var_Parse(condExpr, VAR_CMD, eflags, &len, freeIt);
if (str == var_Error) {
if (*freeIt) {
free(*freeIt);
*freeIt = NULL;
}
/*
* Even if !doEval, we still report syntax errors, which
* is what getting var_Error back with !doEval means.
*/
str = NULL;
goto cleanup;
}
condExpr += len;
/*
* If the '$' 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:
if (strictLHS && !qt && *start != '$' &&
!isdigit((unsigned char)*start)) {
/* lhs must be quoted, a variable reference or number */
if (*freeIt) {
free(*freeIt);
*freeIt = NULL;
}
str = NULL;
goto cleanup;
}
Buf_AddByte(&buf, *condExpr);
break;
}
}
got_str:
*freeIt = Buf_GetAll(&buf, NULL);
str = *freeIt;
cleanup:
Buf_Destroy(&buf, FALSE);
return str;
}
/* The different forms of #if's. */
static const struct If {
const char *form; /* Form of if */
size_t 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 }
};
/*-
* Return the next token from the input.
*
* Side Effects:
* condPushback will be set back to TOK_NONE if it is used.
*/
static Token
compare_expression(Boolean doEval)
{
Token t;
const char *lhs;
const char *rhs;
const char *op;
void *lhsFree;
void *rhsFree;
Boolean lhsQuoted;
Boolean rhsQuoted;
double left, right;
t = TOK_ERROR;
rhs = NULL;
lhsFree = rhsFree = NULL;
lhsQuoted = rhsQuoted = FALSE;
/*
* Parse the variable spec and skip over it, saving its
* value in lhs.
*/
lhs = CondGetString(doEval, &lhsQuoted, &lhsFree, lhsStrict);
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 <number> 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, FALSE);
if (!rhs)
goto done;
if (!doEval) {
t = TOK_FALSE;
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:
free(lhsFree);
free(rhsFree);
return t;
}
static int
get_mpt_arg(Boolean doEval, const char **linePtr, char **argPtr,
const char *func MAKE_ATTR_UNUSED)
{
/*
* Use Var_Parse to parse the spec in parens and return
* TOK_TRUE if the resulting string is empty.
*/
int length;
void *freeIt;
const char *val;
const 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, doEval ? VARE_WANTRES : 0, &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[0]))
val++;
/*
* For consistency with the other functions we can't generate the
* true/false here.
*/
length = *val ? 2 : 1;
free(freeIt);
return length;
}
static Boolean
CondDoEmpty(int arglen, const char *arg MAKE_ATTR_UNUSED)
{
return arglen == 1;
}
static Token
compare_function(Boolean doEval)
{
static const struct fn_def {
const char *fn_name;
size_t fn_name_len;
int (*fn_getarg)(Boolean, const 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;
const char *cp = condExpr;
const 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(doEval, &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);
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(doEval, &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;
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;
}
static CondEvalResult
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_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:
* Any effects from evaluating the variables.
*-----------------------------------------------------------------------
*/
CondEvalResult
Cond_EvalExpression(const struct If *info, char *line, Boolean *value,
int eprint, Boolean strictLHS)
{
static const struct If *dflt_info;
const struct If *sv_if_info = if_info;
const char *sv_condExpr = condExpr;
Token sv_condPushBack = condPushBack;
int rval;
lhsStrict = strictLHS;
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;
}
assert(info != NULL);
if_info = info;
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;
}
/*-
*-----------------------------------------------------------------------
* 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.
*
* 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.
*
* Note that the states IF_ACTIVE and ELSE_ACTIVE are only different in order
* to detect spurious .else lines (as are SKIP_TO_ELSE and SKIP_TO_ENDIF),
* otherwise .else could be treated as '.elif 1'.
*-----------------------------------------------------------------------
*/
CondEvalResult
Cond_Eval(char *line)
{
enum { MAXIF = 128 }; /* maximum depth of .if'ing */
enum { MAXIF_BUMP = 32 }; /* how much to grow by */
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 = NULL;
static unsigned int max_if_depth = MAXIF;
const struct If *ifp;
Boolean isElif;
Boolean value;
int level; /* Level at which to report errors. */
enum if_states state;
level = PARSE_FATAL;
if (!cond_state) {
cond_state = bmake_malloc(max_if_depth * sizeof(*cond_state));
cond_state[0] = IF_ACTIVE;
}
/* 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--;
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;
}
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;
}
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 + 1 >= max_if_depth) {
/*
* This is rare, but not impossible.
* In meta mode, dirdeps.mk (only runs at level 0)
* can need more than the default.
*/
max_if_depth += MAXIF_BUMP;
cond_state = bmake_realloc(cond_state,
max_if_depth * sizeof(*cond_state));
}
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, TRUE) == 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;
}
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;
}
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