Return to for.c CVS log

Up to [cvs.NetBSD.org] / src / usr.bin / make

Begin cleanup of the make parser: separate out the logic for reading files
from the parsing goo. This will now use mmap for reading if it works and
fall back to read only for pipes and such. Step 1 of a cleanup program
proposed without objection on tech-toolchain.

/*	$NetBSD: for.c,v 1.48 2010/12/25 04:57:07 dholland 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 1.48 2010/12/25 04:57:07 dholland 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 1.48 2010/12/25 04:57:07 dholland 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;

    /* 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);

    for (ptr = sub;; ptr += len) {
	while (*ptr && isspace((unsigned char)*ptr))
	    ptr++;
	if (*ptr == 0)
	    break;
	escapes = 0;
	for (len = 0; (ch = ptr[len]) != 0 && !isspace(ch); len++) {
	    if (ch == ':' || ch == '$' || ch == '\\')
		escapes |= FOR_SUB_ESCAPE_CHAR;
	    else if (ch == ')')
		escapes |= FOR_SUB_ESCAPE_PAREN;
	    else if (ch == /*{*/ '}')
		escapes |= FOR_SUB_ESCAPE_BRACE;
	}
	strlist_add_str(&new_for->items, make_str(ptr, len), escapes);
    }

    free(sub);

    if (strlist_num(&new_for->items) % strlist_num(&new_for->vars)) {
	Parse_Error(PARSE_FATAL,
		"Wrong number of words (%d) in .for substitution list"
		" with %d vars",
		strlist_num(&new_for->items), strlist_num(&new_for->vars));
	/*
	 * 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);
}