NetBSD/usr.bin/make/for.c
2020-09-28 20:46:11 +00:00

462 lines
12 KiB
C

/* $NetBSD: for.c,v 1.89 2020/09/28 20:46:11 rillig 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.
*/
/*-
* Handling of .for/.endfor loops in a makefile.
*
* For loops are of the form:
*
* .for <varname...> in <value...>
* ...
* .endfor
*
* When a .for line is parsed, all following lines are accumulated into a
* buffer, up to but excluding the corresponding .endfor line. To find the
* corresponding .endfor, the number of nested .for and .endfor directives
* are counted.
*
* During parsing, any nested .for loops are just passed through; they get
* handled recursively in For_Eval when the enclosing .for loop is evaluated
* in For_Run.
*
* When the .for loop has been parsed completely, the variable expressions
* for the iteration variables are replaced with expressions of the form
* ${:Uvalue}, and then this modified body is "included" as a special file.
*
* Interface:
* For_Eval Evaluate the loop in the passed line.
*
* For_Run Run accumulated loop
*/
#include "make.h"
#include "strlist.h"
/* "@(#)for.c 8.1 (Berkeley) 6/6/93" */
MAKE_RCSID("$NetBSD: for.c,v 1.89 2020/09/28 20:46:11 rillig Exp $");
typedef enum {
FOR_SUB_ESCAPE_CHAR = 0x0001,
FOR_SUB_ESCAPE_BRACE = 0x0002,
FOR_SUB_ESCAPE_PAREN = 0x0004
} ForEscapes;
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;
/* Is any of the names 1 character long? If so, when the variable values
* are substituted, the parser must handle $V expressions as well, not
* only ${V} and $(V). */
Boolean short_var;
int sub_next;
} For;
static For *accumFor; /* Loop being accumulated */
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);
}
/* Evaluate the for loop in the passed line. The line looks like this:
* .for <varname...> in <value...>
*
* 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.
*/
int
For_Eval(const char *line)
{
For *new_for;
const char *ptr;
Words words;
/* Skip the '.' and any following whitespace */
for (ptr = line + 1; ch_isspace(*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' ||
!ch_isspace(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);
Buf_Init(&new_for->buf, 0);
strlist_init(&new_for->vars);
strlist_init(&new_for->items);
new_for->parse_buf = NULL;
new_for->short_var = FALSE;
new_for->sub_next = 0;
/* Grab the variables. Terminate on "in". */
while (TRUE) {
size_t len;
while (ch_isspace(*ptr))
ptr++;
if (*ptr == '\0') {
Parse_Error(PARSE_FATAL, "missing `in' in for");
For_Free(new_for);
return -1;
}
for (len = 1; ptr[len] && !ch_isspace(ptr[len]); len++)
continue;
if (len == 2 && ptr[0] == 'i' && ptr[1] == 'n') {
ptr += 2;
break;
}
if (len == 1)
new_for->short_var = TRUE;
strlist_add_str(&new_for->vars, bmake_strldup(ptr, len), len);
ptr += len;
}
if (strlist_num(&new_for->vars) == 0) {
Parse_Error(PARSE_FATAL, "no iteration variables in for");
For_Free(new_for);
return -1;
}
while (ch_isspace(*ptr))
ptr++;
/*
* Make a list with the remaining words.
* The values are later substituted as ${:U<value>...} so we must
* backslash-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 will be substituting into ${...} or $(...).
*/
{
char *items;
(void)Var_Subst(ptr, VAR_GLOBAL, VARE_WANTRES, &items);
/* TODO: handle errors */
words = Str_Words(items, FALSE);
free(items);
}
{
size_t n;
for (n = 0; n < words.len; n++) {
ForEscapes escapes;
char ch;
ptr = words.words[n];
if (ptr[0] == '\0')
continue;
escapes = 0;
while ((ch = *ptr++)) {
switch (ch) {
case ':':
case '$':
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.words[n]),
escapes);
}
}
Words_Free(words);
{
size_t len, n;
if ((len = strlist_num(&new_for->items)) > 0 &&
len % (n = strlist_num(&new_for->vars))) {
Parse_Error(PARSE_FATAL,
"Wrong number of words (%zu) in .for substitution list"
" with %zu 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);
}
}
accumFor = new_for;
forLevel = 1;
return 1;
}
/*
* Add another line to a .for loop.
* Returns FALSE when the matching .endfor is reached.
*/
Boolean
For_Accum(const char *line)
{
const char *ptr = line;
if (*ptr == '.') {
for (ptr++; *ptr && ch_isspace(*ptr); ptr++)
continue;
if (strncmp(ptr, "endfor", 6) == 0 && (ch_isspace(ptr[6]) || !ptr[6])) {
DEBUG1(FOR, "For: end for %d\n", forLevel);
if (--forLevel <= 0)
return FALSE;
} else if (strncmp(ptr, "for", 3) == 0 && ch_isspace(ptr[3])) {
forLevel++;
DEBUG1(FOR, "For: new loop %d\n", forLevel);
}
}
Buf_AddStr(&accumFor->buf, line);
Buf_AddByte(&accumFor->buf, '\n');
return TRUE;
}
static size_t
for_var_len(const char *var)
{
char ch, var_start, var_end;
int depth;
size_t 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);
ForEscapes escapes = strlist_info(items, item_no);
char ch;
/* If there were no escapes, or the only escape is the other variable
* terminator, then just substitute the full string */
if (!(escapes &
(ech == ')' ? ~FOR_SUB_ESCAPE_BRACE : ~FOR_SUB_ESCAPE_PAREN))) {
Buf_AddStr(cmds, item);
return;
}
/* Escape ':', '$', '\\' and 'ech' - these will be removed later by
* :U processing, see ApplyModifier_Defined. */
while ((ch = *item++) != 0) {
if (ch == '$') {
size_t len = for_var_len(item);
if (len != 0) {
Buf_AddBytes(cmds, item - 1, len + 1);
item += len;
continue;
}
Buf_AddByte(cmds, '\\');
} else if (ch == ':' || ch == '\\' || ch == ech)
Buf_AddByte(cmds, '\\');
Buf_AddByte(cmds, ch);
}
}
static char *
ForIterate(void *v_arg, size_t *ret_len)
{
For *arg = v_arg;
int i;
char *var;
const char *cp;
const char *cmd_cp;
const char *body_end;
char ch;
Buffer cmds;
char *cmds_str;
size_t cmd_len;
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 substitutions of the loop control variable is naive.
* Many of the modifiers use \ to escape $ (not $) so it is possible
* to contrive a makefile where an unwanted substitution happens.
*/
cmd_cp = Buf_GetAll(&arg->buf, &cmd_len);
body_end = cmd_cp + cmd_len;
Buf_Init(&cmds, cmd_len + 256);
for (cp = cmd_cp; (cp = strchr(cp, '$')) != NULL;) {
char ech;
ch = *++cp;
if ((ch == '(' && (ech = ')', 1)) || (ch == '{' && (ech = '}', 1))) {
cp++;
/* Check variable name against the .for loop variables */
STRLIST_FOREACH(var, &arg->vars, i) {
size_t vlen = strlist_info(&arg->vars, i);
if (memcmp(cp, var, vlen) != 0)
continue;
if (cp[vlen] != ':' && cp[vlen] != ech && cp[vlen] != '\\')
continue;
/* Found a variable match. Replace with :U<value> */
Buf_AddBytesBetween(&cmds, cmd_cp, cp);
Buf_AddStr(&cmds, ":U");
cp += vlen;
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_AddBytesBetween(&cmds, cmd_cp, cp);
Buf_AddStr(&cmds, "{:U");
cmd_cp = ++cp;
for_substitute(&cmds, &arg->items, arg->sub_next + i, '}');
Buf_AddByte(&cmds, '}');
break;
}
}
Buf_AddBytesBetween(&cmds, cmd_cp, body_end);
*ret_len = Buf_Len(&cmds);
cmds_str = Buf_Destroy(&cmds, FALSE);
DEBUG1(FOR, "For: loop body:\n%s", cmds_str);
arg->sub_next += strlist_num(&arg->vars);
arg->parse_buf = cmds_str;
return cmds_str;
}
/* Run the for loop, imitating the actions of an include file. */
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, ForIterate, arg);
}