/*
* 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 have the form:
*
* .for <varname...> in <value...>
* # the body
* .endfor
*
* When a .for line is parsed, the following lines are copied to the body of
* the .for loop, until the corresponding .endfor line is reached. In this
* phase, the body is not yet evaluated. This also applies to any nested
* .for loops.
*
* After reaching the .endfor, the values from the .for line are grouped
* according to the number of variables. For each such group, the unexpanded
* body is scanned for expressions, and those that match the
* variable names are replaced with expressions of the form ${:U...}. After
* that, the body is treated like a file from an .include directive.
*
* Interface:
* For_Eval Evaluate the loop in the passed line.
*
* For_Run Run accumulated loop
*/
if (f->items.len == 1 && Substring_IsEmpty(f->items.words[0]))
f->items.len = 0; /* .for var in ${:U} */
if (f->items.len % f->vars.len != 0) {
Parse_Error(PARSE_FATAL,
"Wrong number of words (%u) in .for "
"substitution list with %u variables",
(unsigned)f->items.len, (unsigned)f->vars.len);
return false;
}
/*
* Evaluate the for loop in the passed line. The line looks like this:
* .for <varname...> in <value...>
*
* Results:
* 0 not a .for directive
* 1 found a .for directive
* -1 erroneous .for directive
*/
int
For_Eval(const char *line)
{
const char *p;
ForLoop *f;
p = line + 1; /* skip the '.' */
skip_whitespace_or_line_continuation(&p);
if (IsFor(p)) {
p += 3;
f = ForLoop_New();
ForLoop_ParseVarnames(f, &p);
if (f->vars.len > 0 && !ForLoop_ParseItems(f, p))
f->items.len = 0; /* don't iterate */
/*
* Add another line to the .for loop that is being built up.
* Returns false when the matching .endfor is reached.
*/
bool
For_Accum(const char *line, int *forLevel)
{
const char *p = line;
if (*p == '.') {
p++;
skip_whitespace_or_line_continuation(&p);
if (IsEndfor(p)) {
DEBUG1(FOR, "For: end for %d\n", *forLevel);
if (--*forLevel == 0)
return false;
} else if (IsFor(p)) {
(*forLevel)++;
DEBUG1(FOR, "For: new loop %d\n", *forLevel);
}
}
/*
* When the body of a '.for i' loop is prepared for an iteration, each
* occurrence of $i in the body is replaced with ${:U...}, inserting the
* value of the item. If this item contains a '$', it may be the start of an
* expression. This expression is copied verbatim, its length is
* determined here, in a rather naive way, ignoring escape characters and
* funny delimiters in modifiers like ':S}from}to}'.
*/
static size_t
ExprLen(const char *s, const char *e)
{
char expr_open, expr_close;
int depth;
const char *p;
if (s == e)
return 0; /* just escape the '$' */
expr_open = s[0];
if (expr_open == '(')
expr_close = ')';
else if (expr_open == '{')
expr_close = '}';
else
return 1; /* Single char variable */
depth = 1;
for (p = s + 1; p != e; p++) {
if (*p == expr_open)
depth++;
else if (*p == expr_close && --depth == 0)
return (size_t)(p + 1 - s);
}
/* Expression end not found, escape the $ */
return 0;
}
/*
* While expanding the body of a .for loop, write the item as a ${:U...}
* expression, escaping characters as needed. The result is later unescaped
* by ApplyModifier_Defined.
*/
static void
AddEscaped(Buffer *body, Substring item, char endc)
{
const char *p;
char ch;
for (p = item.start; p != item.end;) {
ch = *p;
if (ch == '$') {
size_t len = ExprLen(p + 1, item.end);
if (len != 0) {
/*
* XXX: Should a '\' be added here?
* See directive-for-escape.mk, ExprLen.
*/
Buf_AddBytes(body, p, 1 + len);
p += 1 + len;
continue;
}
Buf_AddByte(body, '\\');
} else if (ch == ':' || ch == '\\' || ch == endc)
Buf_AddByte(body, '\\');
else if (ch == '\n') {
Parse_Error(PARSE_FATAL, "newline in .for value");
ch = ' '; /* prevent newline injection */
}
Buf_AddByte(body, ch);
p++;
}
}
/*
* While expanding the body of a .for loop, replace the variable name of an
* expression like ${i} or ${i:...} or $(i) or $(i:...) with ":Uvalue".
*/
static void
ForLoop_SubstVarLong(ForLoop *f, unsigned firstItem, Buffer *body,
const char **pp, char endc, const char **inout_mark)
{
size_t i;
const char *start = *pp;
const char **varnames = Vector_Get(&f->vars, 0);
for (i = 0; i < f->vars.len; i++) {
const char *p = start;
if (!cpp_skip_string(&p, varnames[i]))
continue;
/* XXX: why test for backslash here? */
if (*p != ':' && *p != endc && *p != '\\')
continue;
/*
* Found a variable match. Skip over the variable name and
* instead add ':U<value>' to the current body.
*/
Buf_AddRange(body, *inout_mark, start);
Buf_AddStr(body, ":U");
AddEscaped(body, f->items.words[firstItem + i], endc);
*inout_mark = p;
*pp = p;
return;
}
}
/*
* While expanding the body of a .for loop, replace single-character
* expressions like $i with their ${:U...} expansion.
*/
static void
ForLoop_SubstVarShort(ForLoop *f, unsigned firstItem, Buffer *body,
const char *p, const char **inout_mark)
{
char ch = *p;
const char **vars;
size_t i;
/*
* Compute the body for the current iteration by copying the unexpanded body,
* replacing the expressions for the iteration variables on the way.
*
* Using expressions ensures that the .for loop can't generate
* syntax, and that the later parsing will still see an expression.
* This code assumes that the variable with the empty name is never defined,
* see unit-tests/varname-empty.mk.
*
* The detection of substitutions of the loop control variables is naive.
* Many of the modifiers use '\$' instead of '$$' to escape '$', so it is
* possible to contrive a makefile where an unwanted substitution happens.
* See unit-tests/directive-for-escape.mk.
*/
static void
ForLoop_SubstBody(ForLoop *f, unsigned firstItem, Buffer *body)
{
const char *p, *end;
const char *mark; /* where the last substitution left off */
Buf_Clear(body);
mark = f->body.data;
end = f->body.data + f->body.len;
for (p = mark; (p = strchr(p, '$')) != NULL;) {
if (p[1] == '{' || p[1] == '(') {
char endc = p[1] == '{' ? '}' : ')';
p += 2;
ForLoop_SubstVarLong(f, firstItem, body,
&p, endc, &mark);
} else {
ForLoop_SubstVarShort(f, firstItem, body,
p + 1, &mark);
p += 2;
}
}
Buf_AddRange(body, mark, end);
}
/*
* Compute the body for the current iteration by copying the unexpanded body,
* replacing the expressions for the iteration variables on the way.
*/
bool
For_NextIteration(ForLoop *f, Buffer *body)
{
if (f->nextItem == f->items.len)
return false;
f->nextItem += (unsigned)f->vars.len;
ForLoop_SubstBody(f, f->nextItem - (unsigned)f->vars.len, body);
if (DEBUG(FOR)) {
char *details = ForLoop_Details(f);
debug_printf("For: loop body with %s:\n%s",
details, body->data);
free(details);
}
return true;
}
/* Break out of the .for loop. */
void
For_Break(ForLoop *f)
{
f->nextItem = (unsigned)f->items.len;
}
/* Run the .for loop, imitating the actions of an include file. */
void
For_Run(unsigned headLineno, unsigned bodyReadLines)
{
Buffer buf;
ForLoop *f = accumFor;
accumFor = NULL;
