freebsd-src/for.c

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/* $NetBSD: for.c,v 1.49 2012/06/03 04:29:40 sjg Exp $ */
/*
* Copyright (c) 1992, The Regents of the University of California.
* All rights reserved.
*
* 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.
*/
#ifndef MAKE_NATIVE
static char rcsid[] = "$NetBSD: for.c,v 1.49 2012/06/03 04:29:40 sjg Exp $";
#else
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)for.c 8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: for.c,v 1.49 2012/06/03 04:29:40 sjg Exp $");
#endif
#endif /* not lint */
#endif
/*-
* for.c --
* Functions to handle loops in a makefile.
*
* Interface:
* For_Eval Evaluate the loop in the passed line.
* For_Run Run accumulated loop
*
*/
#include <assert.h>
#include <ctype.h>
#include "make.h"
#include "hash.h"
#include "dir.h"
#include "buf.h"
#include "strlist.h"
#define FOR_SUB_ESCAPE_CHAR 1
#define FOR_SUB_ESCAPE_BRACE 2
#define FOR_SUB_ESCAPE_PAREN 4
/*
* For statements are of the form:
*
* .for <variable> in <varlist>
* ...
* .endfor
*
* The trick is to look for the matching end inside for for loop
* To do that, we count the current nesting level of the for loops.
* and the .endfor statements, accumulating all the statements between
* the initial .for loop and the matching .endfor;
* then we evaluate the for loop for each variable in the varlist.
*
* Note that any nested fors are just passed through; they get handled
* recursively in For_Eval when we're expanding the enclosing for in
* For_Run.
*/
static int forLevel = 0; /* Nesting level */
/*
* State of a for loop.
*/
typedef struct _For {
Buffer buf; /* Body of loop */
strlist_t vars; /* Iteration variables */
strlist_t items; /* Substitution items */
char *parse_buf;
int short_var;
int sub_next;
} For;
static For *accumFor; /* Loop being accumulated */
static char *
make_str(const char *ptr, int len)
{
char *new_ptr;
new_ptr = bmake_malloc(len + 1);
memcpy(new_ptr, ptr, len);
new_ptr[len] = 0;
return new_ptr;
}
static void
For_Free(For *arg)
{
Buf_Destroy(&arg->buf, TRUE);
strlist_clean(&arg->vars);
strlist_clean(&arg->items);
free(arg->parse_buf);
free(arg);
}
/*-
*-----------------------------------------------------------------------
* For_Eval --
* Evaluate the for loop in the passed line. The line
* looks like this:
* .for <variable> in <varlist>
*
* Input:
* line Line to parse
*
* Results:
* 0: Not a .for statement, parse the line
* 1: We found a for loop
* -1: A .for statement with a bad syntax error, discard.
*
* Side Effects:
* None.
*
*-----------------------------------------------------------------------
*/
int
For_Eval(char *line)
{
For *new_for;
char *ptr = line, *sub;
int len;
int escapes;
unsigned char ch;
char **words, *word_buf;
int n, nwords;
/* Skip the '.' and any following whitespace */
for (ptr++; *ptr && isspace((unsigned char) *ptr); ptr++)
continue;
/*
* If we are not in a for loop quickly determine if the statement is
* a for.
*/
if (ptr[0] != 'f' || ptr[1] != 'o' || ptr[2] != 'r' ||
!isspace((unsigned char) ptr[3])) {
if (ptr[0] == 'e' && strncmp(ptr+1, "ndfor", 5) == 0) {
Parse_Error(PARSE_FATAL, "for-less endfor");
return -1;
}
return 0;
}
ptr += 3;
/*
* we found a for loop, and now we are going to parse it.
*/
new_for = bmake_malloc(sizeof *new_for);
memset(new_for, 0, sizeof *new_for);
/* Grab the variables. Terminate on "in". */
for (;; ptr += len) {
while (*ptr && isspace((unsigned char) *ptr))
ptr++;
if (*ptr == '\0') {
Parse_Error(PARSE_FATAL, "missing `in' in for");
For_Free(new_for);
return -1;
}
for (len = 1; ptr[len] && !isspace((unsigned char)ptr[len]); len++)
continue;
if (len == 2 && ptr[0] == 'i' && ptr[1] == 'n') {
ptr += 2;
break;
}
if (len == 1)
new_for->short_var = 1;
strlist_add_str(&new_for->vars, make_str(ptr, len), len);
}
if (strlist_num(&new_for->vars) == 0) {
Parse_Error(PARSE_FATAL, "no iteration variables in for");
For_Free(new_for);
return -1;
}
while (*ptr && isspace((unsigned char) *ptr))
ptr++;
/*
* Make a list with the remaining words
* The values are substituted as ${:U<value>...} so we must \ escape
* characters that break that syntax.
* Variables are fully expanded - so it is safe for escape $.
* We can't do the escapes here - because we don't know whether
* we are substuting into ${...} or $(...).
*/
sub = Var_Subst(NULL, ptr, VAR_GLOBAL, FALSE);
/*
* Split into words allowing for quoted strings.
*/
words = brk_string(sub, &nwords, FALSE, &word_buf);
free(sub);
if (words != NULL) {
for (n = 0; n < nwords; n++) {
ptr = words[n];
if (!*ptr)
continue;
escapes = 0;
while ((ch = *ptr++)) {
switch(ch) {
case ':':
case '$':
case '\\':
escapes |= FOR_SUB_ESCAPE_CHAR;
break;
case ')':
escapes |= FOR_SUB_ESCAPE_PAREN;
break;
case /*{*/ '}':
escapes |= FOR_SUB_ESCAPE_BRACE;
break;
}
}
/*
* We have to dup words[n] to maintain the semantics of
* strlist.
*/
strlist_add_str(&new_for->items, bmake_strdup(words[n]), escapes);
}
free(words);
free(word_buf);
if ((len = strlist_num(&new_for->items)) > 0 &&
len % (n = strlist_num(&new_for->vars))) {
Parse_Error(PARSE_FATAL,
"Wrong number of words (%d) in .for substitution list"
" with %d vars", len, n);
/*
* Return 'success' so that the body of the .for loop is
* accumulated.
* Remove all items so that the loop doesn't iterate.
*/
strlist_clean(&new_for->items);
}
}
Buf_Init(&new_for->buf, 0);
accumFor = new_for;
forLevel = 1;
return 1;
}
/*
* Add another line to a .for loop.
* Returns 0 when the matching .endfor is reached.
*/
int
For_Accum(char *line)
{
char *ptr = line;
if (*ptr == '.') {
for (ptr++; *ptr && isspace((unsigned char) *ptr); ptr++)
continue;
if (strncmp(ptr, "endfor", 6) == 0 &&
(isspace((unsigned char) ptr[6]) || !ptr[6])) {
if (DEBUG(FOR))
(void)fprintf(debug_file, "For: end for %d\n", forLevel);
if (--forLevel <= 0)
return 0;
} else if (strncmp(ptr, "for", 3) == 0 &&
isspace((unsigned char) ptr[3])) {
forLevel++;
if (DEBUG(FOR))
(void)fprintf(debug_file, "For: new loop %d\n", forLevel);
}
}
Buf_AddBytes(&accumFor->buf, strlen(line), line);
Buf_AddByte(&accumFor->buf, '\n');
return 1;
}
/*-
*-----------------------------------------------------------------------
* For_Run --
* Run the for loop, imitating the actions of an include file
*
* Results:
* None.
*
* Side Effects:
* None.
*
*-----------------------------------------------------------------------
*/
static int
for_var_len(const char *var)
{
char ch, var_start, var_end;
int depth;
int len;
var_start = *var;
if (var_start == 0)
/* just escape the $ */
return 0;
if (var_start == '(')
var_end = ')';
else if (var_start == '{')
var_end = '}';
else
/* Single char variable */
return 1;
depth = 1;
for (len = 1; (ch = var[len++]) != 0;) {
if (ch == var_start)
depth++;
else if (ch == var_end && --depth == 0)
return len;
}
/* Variable end not found, escape the $ */
return 0;
}
static void
for_substitute(Buffer *cmds, strlist_t *items, unsigned int item_no, char ech)
{
const char *item = strlist_str(items, item_no);
int len;
char ch;
/* If there were no escapes, or the only escape is the other variable
* terminator, then just substitute the full string */
if (!(strlist_info(items, item_no) &
(ech == ')' ? ~FOR_SUB_ESCAPE_BRACE : ~FOR_SUB_ESCAPE_PAREN))) {
Buf_AddBytes(cmds, strlen(item), item);
return;
}
/* Escape ':', '$', '\\' and 'ech' - removed by :U processing */
while ((ch = *item++) != 0) {
if (ch == '$') {
len = for_var_len(item);
if (len != 0) {
Buf_AddBytes(cmds, len + 1, item - 1);
item += len;
continue;
}
Buf_AddByte(cmds, '\\');
} else if (ch == ':' || ch == '\\' || ch == ech)
Buf_AddByte(cmds, '\\');
Buf_AddByte(cmds, ch);
}
}
static char *
For_Iterate(void *v_arg, size_t *ret_len)
{
For *arg = v_arg;
int i, len;
char *var;
char *cp;
char *cmd_cp;
char *body_end;
char ch;
Buffer cmds;
if (arg->sub_next + strlist_num(&arg->vars) > strlist_num(&arg->items)) {
/* No more iterations */
For_Free(arg);
return NULL;
}
free(arg->parse_buf);
arg->parse_buf = NULL;
/*
* Scan the for loop body and replace references to the loop variables
* with variable references that expand to the required text.
* Using variable expansions ensures that the .for loop can't generate
* syntax, and that the later parsing will still see a variable.
* We assume that the null variable will never be defined.
*
* The detection of substitions of the loop control variable is naive.
* Many of the modifiers use \ to escape $ (not $) so it is possible
* to contrive a makefile where an unwanted substitution happens.
*/
cmd_cp = Buf_GetAll(&arg->buf, &len);
body_end = cmd_cp + len;
Buf_Init(&cmds, len + 256);
for (cp = cmd_cp; (cp = strchr(cp, '$')) != NULL;) {
char ech;
ch = *++cp;
if ((ch == '(' && (ech = ')')) || (ch == '{' && (ech = '}'))) {
cp++;
/* Check variable name against the .for loop variables */
STRLIST_FOREACH(var, &arg->vars, i) {
len = strlist_info(&arg->vars, i);
if (memcmp(cp, var, len) != 0)
continue;
if (cp[len] != ':' && cp[len] != ech && cp[len] != '\\')
continue;
/* Found a variable match. Replace with :U<value> */
Buf_AddBytes(&cmds, cp - cmd_cp, cmd_cp);
Buf_AddBytes(&cmds, 2, ":U");
cp += len;
cmd_cp = cp;
for_substitute(&cmds, &arg->items, arg->sub_next + i, ech);
break;
}
continue;
}
if (ch == 0)
break;
/* Probably a single character name, ignore $$ and stupid ones. {*/
if (!arg->short_var || strchr("}):$", ch) != NULL) {
cp++;
continue;
}
STRLIST_FOREACH(var, &arg->vars, i) {
if (var[0] != ch || var[1] != 0)
continue;
/* Found a variable match. Replace with ${:U<value>} */
Buf_AddBytes(&cmds, cp - cmd_cp, cmd_cp);
Buf_AddBytes(&cmds, 3, "{:U");
cmd_cp = ++cp;
for_substitute(&cmds, &arg->items, arg->sub_next + i, /*{*/ '}');
Buf_AddBytes(&cmds, 1, "}");
break;
}
}
Buf_AddBytes(&cmds, body_end - cmd_cp, cmd_cp);
cp = Buf_Destroy(&cmds, FALSE);
if (DEBUG(FOR))
(void)fprintf(debug_file, "For: loop body:\n%s", cp);
arg->sub_next += strlist_num(&arg->vars);
arg->parse_buf = cp;
*ret_len = strlen(cp);
return cp;
}
void
For_Run(int lineno)
{
For *arg;
arg = accumFor;
accumFor = NULL;
if (strlist_num(&arg->items) == 0) {
/* Nothing to expand - possibly due to an earlier syntax error. */
For_Free(arg);
return;
}
Parse_SetInput(NULL, lineno, -1, For_Iterate, arg);
}