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342 lines
8.5 KiB
C
342 lines
8.5 KiB
C
/* Variable expansion functions for GNU Make.
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Copyright (C) 1988, 1989, 1991 Free Software Foundation, Inc.
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This file is part of GNU Make.
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GNU Make is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Make is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Make; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include "make.h"
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#include "commands.h"
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#include "file.h"
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#include "variable.h"
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/* Recursively expand V. The returned string is malloc'd. */
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static char *
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recursively_expand (v)
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register struct variable *v;
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{
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char *value;
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if (v->expanding)
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{
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/* Expanding V causes infinite recursion. Lose. */
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if (reading_filename == 0)
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fatal ("Recursive variable `%s' references itself (eventually)",
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v->name);
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else
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makefile_fatal
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(reading_filename, *reading_lineno_ptr,
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"Recursive variable `%s' references itself (eventually)",
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v->name);
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}
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v->expanding = 1;
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value = allocated_variable_expand (v->value);
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v->expanding = 0;
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return value;
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}
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/* Scan LINE for variable references and expansion-function calls.
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Build in `variable_buffer' the result of expanding the references and calls.
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Return the address of the resulting string, which is null-terminated
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and is valid only until the next time this function is called. */
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char *
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variable_expand (line)
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register char *line;
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{
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register struct variable *v;
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register char *p, *o, *p1;
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p = line;
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o = initialize_variable_output ();
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while (1)
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{
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/* Copy all following uninteresting chars all at once to the
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variable output buffer, and skip them. Uninteresting chars end
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at the next $ or the end of the input. */
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p1 = index (p, '$');
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o = variable_buffer_output (o, p, p1 != 0 ? p1 - p : strlen (p) + 1);
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if (p1 == 0)
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break;
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p = p1 + 1;
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/* Dispatch on the char that follows the $. */
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switch (*p)
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{
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case '$':
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/* $$ seen means output one $ to the variable output buffer. */
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o = variable_buffer_output (o, p, 1);
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break;
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case '(':
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case '{':
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/* $(...) or ${...} is the general case of substitution. */
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{
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char openparen = *p;
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char closeparen = (openparen == '(') ? ')' : '}';
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register char *beg = p + 1;
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char *op, *begp;
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char *end;
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op = o;
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begp = p;
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if (handle_function (&op, &begp))
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{
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o = op;
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p = begp;
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break;
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}
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/* Is there a variable reference inside the parens or braces?
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If so, expand it before expanding the entire reference. */
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p1 = index (beg, closeparen);
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if (p1 != 0)
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p1 = lindex (beg, p1, '$');
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if (p1 != 0)
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{
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/* BEG now points past the opening paren or brace.
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Count parens or braces until it is matched. */
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int count = 0;
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for (p = beg; *p != '\0'; ++p)
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{
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if (*p == openparen)
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++count;
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else if (*p == closeparen && --count < 0)
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break;
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}
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/* If count is >= 0, there were unmatched opening parens
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or braces, so we go to the simple case of a variable name
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such as `$($(a)'. */
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if (count < 0)
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{
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char *name = expand_argument (beg, p);
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static char start[3] = { '$', }, end[2];
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start[1] = openparen;
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end[0] = closeparen;
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p1 = concat (start, name, end);
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free (name);
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name = allocated_variable_expand (p1);
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o = variable_buffer_output (o, name, strlen (name));
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free (name);
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break;
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}
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}
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/* This is not a reference to a built-in function and
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it does not contain any variable references inside.
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There are several things it could be. */
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p = index (beg, ':');
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if (p != 0 && lindex (beg, p, closeparen) == 0)
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{
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/* This is a substitution reference: $(FOO:A=B). */
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int count;
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char *subst_beg, *replace_beg;
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unsigned int subst_len, replace_len;
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v = lookup_variable (beg, p - beg);
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subst_beg = p + 1;
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count = 0;
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for (p = subst_beg; *p != '\0'; ++p)
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{
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if (*p == openparen)
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++count;
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else if (*p == closeparen)
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--count;
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else if (*p == '=' && count <= 0)
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break;
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}
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if (count > 0)
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/* There were unmatched opening parens. */
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return initialize_variable_output ();
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subst_len = p - subst_beg;
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replace_beg = p + 1;
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count = 0;
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for (p = replace_beg; *p != '\0'; ++p)
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{
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if (*p == openparen)
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++count;
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else if (*p == closeparen && --count < 0)
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break;
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}
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if (count > 0)
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/* There were unmatched opening parens. */
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return initialize_variable_output ();
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end = p;
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replace_len = p - replace_beg;
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if (v != 0 && *v->value != '\0')
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{
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char *value = (v->recursive ? recursively_expand (v)
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: v->value);
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if (lindex (subst_beg, subst_beg + subst_len, '%') != 0)
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{
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p = savestring (subst_beg, subst_len);
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p1 = savestring (replace_beg, replace_len);
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o = patsubst_expand (o, value, p, p1,
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index (p, '%'), index (p1, '%'));
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free (p);
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free (p1);
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}
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else
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o = subst_expand (o, value, subst_beg, replace_beg,
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subst_len, replace_len, 0, 1);
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if (v->recursive)
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free (value);
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}
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}
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/* No, this must be an ordinary variable reference. */
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else
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{
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/* Look up the value of the variable. */
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end = index (beg, closeparen);
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if (end == 0)
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return initialize_variable_output ();
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v = lookup_variable (beg, end - beg);
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if (v != 0 && *v->value != '\0')
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{
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char *value = (v->recursive ? recursively_expand (v)
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: v->value);
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o = variable_buffer_output (o, value, strlen (value));
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if (v->recursive)
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free (value);
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}
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}
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/* Advance p past the variable reference to resume scan. */
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p = end;
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}
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break;
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case '\0':
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break;
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default:
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if (isblank (p[-1]))
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break;
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/* A $ followed by a random char is a variable reference:
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$a is equivalent to $(a). */
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{
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/* We could do the expanding here, but this way
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avoids code repetition at a small performance cost. */
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char name[5];
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name[0] = '$';
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name[1] = '(';
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name[2] = *p;
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name[3] = ')';
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name[4] = '\0';
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p1 = allocated_variable_expand (name);
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o = variable_buffer_output (o, p1, strlen (p1));
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free (p1);
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}
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break;
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}
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if (*p == '\0')
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break;
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else
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++p;
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}
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(void) variable_buffer_output (o, "", 1);
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return initialize_variable_output ();
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}
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/* Expand an argument for an expansion function.
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The text starting at STR and ending at END is variable-expanded
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into a null-terminated string that is returned as the value.
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This is done without clobbering `variable_buffer' or the current
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variable-expansion that is in progress. */
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char *
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expand_argument (str, end)
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char *str, *end;
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{
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char *tmp = savestring (str, end - str);
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char *value = allocated_variable_expand (tmp);
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free (tmp);
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return value;
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}
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/* Expand LINE for FILE. Error messages refer to the file and line where
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FILE's commands were found. Expansion uses FILE's variable set list. */
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char *
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variable_expand_for_file (line, file)
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char *line;
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register struct file *file;
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{
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char *result;
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struct variable_set_list *save;
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if (file == 0)
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return variable_expand (line);
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save = current_variable_set_list;
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current_variable_set_list = file->variables;
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reading_filename = file->cmds->filename;
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reading_lineno_ptr = &file->cmds->lineno;
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result = variable_expand (line);
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current_variable_set_list = save;
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reading_filename = 0;
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reading_lineno_ptr = 0;
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return result;
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}
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/* Like variable_expand, but the returned string is malloc'd. */
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char *
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allocated_variable_expand (line)
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char *line;
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{
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return allocated_variable_expand_for_file (line, (struct file *) 0);
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}
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/* Like variable_expand_for_file, but the returned string is malloc'd. */
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char *
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allocated_variable_expand_for_file (line, file)
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char *line;
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struct file *file;
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{
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char *save;
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char *value;
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save = save_variable_output ();
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value = variable_expand_for_file (line, file);
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value = savestring (value, strlen (value));
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restore_variable_output (save);
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return value;
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}
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