mirror of
https://salsa.debian.org/srivasta/make-dfsg.git
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0afbbf8595
it might be needed: for most situations we parse prereqs immediately as we used to. Reduces memory usage. - Fixes Savannah bug #18622.
605 lines
16 KiB
C
605 lines
16 KiB
C
/* Variable expansion functions for GNU Make.
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Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
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1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software
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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 it under the
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terms of the GNU General Public License as published by the Free Software
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Foundation; either version 3 of the License, or (at your option) any later
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version.
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GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
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A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along with
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this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "make.h"
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#include <assert.h>
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#include "filedef.h"
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#include "job.h"
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#include "commands.h"
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#include "variable.h"
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#include "rule.h"
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/* Initially, any errors reported when expanding strings will be reported
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against the file where the error appears. */
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const struct floc **expanding_var = &reading_file;
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/* The next two describe the variable output buffer.
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This buffer is used to hold the variable-expansion of a line of the
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makefile. It is made bigger with realloc whenever it is too small.
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variable_buffer_length is the size currently allocated.
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variable_buffer is the address of the buffer.
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For efficiency, it's guaranteed that the buffer will always have
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VARIABLE_BUFFER_ZONE extra bytes allocated. This allows you to add a few
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extra chars without having to call a function. Note you should never use
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these bytes unless you're _sure_ you have room (you know when the buffer
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length was last checked. */
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#define VARIABLE_BUFFER_ZONE 5
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static unsigned int variable_buffer_length;
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char *variable_buffer;
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/* Subroutine of variable_expand and friends:
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The text to add is LENGTH chars starting at STRING to the variable_buffer.
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The text is added to the buffer at PTR, and the updated pointer into
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the buffer is returned as the value. Thus, the value returned by
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each call to variable_buffer_output should be the first argument to
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the following call. */
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char *
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variable_buffer_output (char *ptr, const char *string, unsigned int length)
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{
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register unsigned int newlen = length + (ptr - variable_buffer);
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if ((newlen + VARIABLE_BUFFER_ZONE) > variable_buffer_length)
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{
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unsigned int offset = ptr - variable_buffer;
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variable_buffer_length = (newlen + 100 > 2 * variable_buffer_length
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? newlen + 100
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: 2 * variable_buffer_length);
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variable_buffer = xrealloc (variable_buffer, variable_buffer_length);
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ptr = variable_buffer + offset;
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}
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memcpy (ptr, string, length);
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return ptr + length;
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}
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/* Return a pointer to the beginning of the variable buffer. */
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static char *
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initialize_variable_output (void)
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{
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/* If we don't have a variable output buffer yet, get one. */
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if (variable_buffer == 0)
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{
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variable_buffer_length = 200;
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variable_buffer = xmalloc (variable_buffer_length);
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variable_buffer[0] = '\0';
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}
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return variable_buffer;
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}
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/* Recursively expand V. The returned string is malloc'd. */
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static char *allocated_variable_append (const struct variable *v);
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char *
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recursively_expand_for_file (struct variable *v, struct file *file)
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{
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char *value;
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const struct floc *this_var;
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const struct floc **saved_varp;
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struct variable_set_list *save = 0;
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int set_reading = 0;
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/* Don't install a new location if this location is empty.
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This can happen for command-line variables, builtin variables, etc. */
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saved_varp = expanding_var;
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if (v->fileinfo.filenm)
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{
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this_var = &v->fileinfo;
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expanding_var = &this_var;
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}
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/* If we have no other file-reading context, use the variable's context. */
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if (!reading_file)
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{
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set_reading = 1;
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reading_file = &v->fileinfo;
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}
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if (v->expanding)
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{
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if (!v->exp_count)
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/* Expanding V causes infinite recursion. Lose. */
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fatal (*expanding_var,
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_("Recursive variable `%s' references itself (eventually)"),
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v->name);
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--v->exp_count;
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}
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if (file)
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{
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save = current_variable_set_list;
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current_variable_set_list = file->variables;
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}
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v->expanding = 1;
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if (v->append)
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value = allocated_variable_append (v);
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else
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value = allocated_variable_expand (v->value);
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v->expanding = 0;
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if (set_reading)
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reading_file = 0;
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if (file)
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current_variable_set_list = save;
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expanding_var = saved_varp;
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return value;
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}
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/* Expand a simple reference to variable NAME, which is LENGTH chars long. */
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#ifdef __GNUC__
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__inline
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#endif
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static char *
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reference_variable (char *o, const char *name, unsigned int length)
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{
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struct variable *v;
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char *value;
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v = lookup_variable (name, length);
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if (v == 0)
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warn_undefined (name, length);
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/* If there's no variable by that name or it has no value, stop now. */
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if (v == 0 || (*v->value == '\0' && !v->append))
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return o;
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value = (v->recursive ? recursively_expand (v) : 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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return o;
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}
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/* Scan STRING for variable references and expansion-function calls. Only
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LENGTH bytes of STRING are actually scanned. If LENGTH is -1, scan until
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a null byte is found.
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Write the results to LINE, which must point into `variable_buffer'. If
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LINE is NULL, start at the beginning of the buffer.
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Return a pointer to LINE, or to the beginning of the buffer if LINE is
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NULL.
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*/
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char *
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variable_expand_string (char *line, const char *string, long length)
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{
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struct variable *v;
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const char *p, *p1;
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char *abuf = NULL;
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char *o;
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unsigned int line_offset;
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if (!line)
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line = initialize_variable_output();
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o = line;
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line_offset = line - variable_buffer;
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if (length == 0)
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{
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variable_buffer_output (o, "", 1);
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return (variable_buffer);
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}
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/* If we want a subset of the string, allocate a temporary buffer for it.
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Most of the functions we use here don't work with length limits. */
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if (length > 0 && string[length] != '\0')
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{
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abuf = xmalloc(length+1);
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memcpy(abuf, string, length);
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abuf[length] = '\0';
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string = abuf;
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}
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p = string;
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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 = strchr (p, '$');
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o = variable_buffer_output (o, p, p1 != 0 ? (unsigned int)(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 ${...} is the general case of substitution. */
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{
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char openparen = *p;
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char closeparen = (openparen == '(') ? ')' : '}';
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const char *begp;
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const char *beg = p + 1;
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char *op;
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char *abeg = NULL;
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const char *end, *colon;
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op = o;
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begp = p;
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if (handle_function (&op, &begp))
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{
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o = op;
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p = begp;
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break;
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}
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/* Is there a variable reference inside the parens or braces?
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If so, expand it before expanding the entire reference. */
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end = strchr (beg, closeparen);
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if (end == 0)
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/* Unterminated variable reference. */
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fatal (*expanding_var, _("unterminated variable reference"));
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p1 = lindex (beg, end, '$');
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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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abeg = expand_argument (beg, p); /* Expand the name. */
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beg = abeg;
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end = strchr (beg, '\0');
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}
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}
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else
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/* Advance P to the end of this reference. After we are
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finished expanding this one, P will be incremented to
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continue the scan. */
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p = end;
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/* This is not a reference to a built-in function and
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any variable references inside are now expanded.
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Is the resultant text a substitution reference? */
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colon = lindex (beg, end, ':');
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if (colon)
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{
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/* This looks like a substitution reference: $(FOO:A=B). */
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const char *subst_beg, *subst_end, *replace_beg, *replace_end;
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subst_beg = colon + 1;
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subst_end = lindex (subst_beg, end, '=');
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if (subst_end == 0)
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/* There is no = in sight. Punt on the substitution
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reference and treat this as a variable name containing
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a colon, in the code below. */
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colon = 0;
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else
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{
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replace_beg = subst_end + 1;
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replace_end = end;
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/* Extract the variable name before the colon
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and look up that variable. */
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v = lookup_variable (beg, colon - beg);
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if (v == 0)
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warn_undefined (beg, colon - beg);
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/* If the variable is not empty, perform the
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substitution. */
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if (v != 0 && *v->value != '\0')
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{
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char *pattern, *replace, *ppercent, *rpercent;
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char *value = (v->recursive
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? recursively_expand (v)
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: v->value);
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/* Copy the pattern and the replacement. Add in an
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extra % at the beginning to use in case there
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isn't one in the pattern. */
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pattern = alloca (subst_end - subst_beg + 2);
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*(pattern++) = '%';
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memcpy (pattern, subst_beg, subst_end - subst_beg);
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pattern[subst_end - subst_beg] = '\0';
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replace = alloca (replace_end - replace_beg + 2);
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*(replace++) = '%';
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memcpy (replace, replace_beg,
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replace_end - replace_beg);
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replace[replace_end - replace_beg] = '\0';
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/* Look for %. Set the percent pointers properly
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based on whether we find one or not. */
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ppercent = find_percent (pattern);
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if (ppercent)
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{
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++ppercent;
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rpercent = find_percent (replace);
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if (rpercent)
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++rpercent;
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}
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else
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{
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ppercent = pattern;
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rpercent = replace;
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--pattern;
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--replace;
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}
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o = patsubst_expand_pat (o, value, pattern, replace,
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ppercent, rpercent);
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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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}
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if (colon == 0)
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/* This is an ordinary variable reference.
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Look up the value of the variable. */
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o = reference_variable (o, beg, end - beg);
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if (abeg)
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free (abeg);
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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 ((unsigned char)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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o = reference_variable (o, p, 1);
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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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++p;
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}
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if (abuf)
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free (abuf);
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variable_buffer_output (o, "", 1);
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return (variable_buffer + line_offset);
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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 (const char *line)
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{
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return variable_expand_string(NULL, line, (long)-1);
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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 (const char *str, const char *end)
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{
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char *tmp, *alloc = NULL;
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char *r;
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if (str == end)
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return xstrdup("");
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if (!end || *end == '\0')
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return allocated_variable_expand (str);
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if (end - str + 1 > 1000)
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tmp = alloc = xmalloc (end - str + 1);
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else
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tmp = alloca (end - str + 1);
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memcpy (tmp, str, end - str);
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tmp[end - str] = '\0';
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r = allocated_variable_expand (tmp);
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if (alloc)
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free (alloc);
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return r;
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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 (const char *line, struct file *file)
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{
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char *result;
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struct variable_set_list *savev;
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const struct floc *savef;
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if (file == 0)
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return variable_expand (line);
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savev = current_variable_set_list;
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current_variable_set_list = file->variables;
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savef = reading_file;
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if (file->cmds && file->cmds->fileinfo.filenm)
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reading_file = &file->cmds->fileinfo;
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else
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reading_file = 0;
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result = variable_expand (line);
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current_variable_set_list = savev;
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reading_file = savef;
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return result;
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}
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/* Like allocated_variable_expand, but for += target-specific variables.
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First recursively construct the variable value from its appended parts in
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any upper variable sets. Then expand the resulting value. */
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static char *
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variable_append (const char *name, unsigned int length,
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const struct variable_set_list *set)
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{
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const struct variable *v;
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char *buf = 0;
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/* If there's nothing left to check, return the empty buffer. */
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if (!set)
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return initialize_variable_output ();
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/* Try to find the variable in this variable set. */
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v = lookup_variable_in_set (name, length, set->set);
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/* If there isn't one, look to see if there's one in a set above us. */
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if (!v)
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return variable_append (name, length, set->next);
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/* If this variable type is append, first get any upper values.
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If not, initialize the buffer. */
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if (v->append)
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buf = variable_append (name, length, set->next);
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else
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buf = initialize_variable_output ();
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/* Append this value to the buffer, and return it.
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If we already have a value, first add a space. */
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if (buf > variable_buffer)
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buf = variable_buffer_output (buf, " ", 1);
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/* Either expand it or copy it, depending. */
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if (! v->recursive)
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return variable_buffer_output (buf, v->value, strlen (v->value));
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buf = variable_expand_string (buf, v->value, strlen (v->value));
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return (buf + strlen (buf));
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}
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static char *
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allocated_variable_append (const struct variable *v)
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{
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char *val;
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/* Construct the appended variable value. */
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char *obuf = variable_buffer;
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unsigned int olen = variable_buffer_length;
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variable_buffer = 0;
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val = variable_append (v->name, strlen (v->name), current_variable_set_list);
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variable_buffer_output (val, "", 1);
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val = variable_buffer;
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variable_buffer = obuf;
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variable_buffer_length = olen;
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return val;
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}
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/* Like variable_expand_for_file, but the returned string is malloc'd.
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This function is called a lot. It wants to be efficient. */
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char *
|
||
allocated_variable_expand_for_file (const char *line, struct file *file)
|
||
{
|
||
char *value;
|
||
|
||
char *obuf = variable_buffer;
|
||
unsigned int olen = variable_buffer_length;
|
||
|
||
variable_buffer = 0;
|
||
|
||
value = variable_expand_for_file (line, file);
|
||
|
||
variable_buffer = obuf;
|
||
variable_buffer_length = olen;
|
||
|
||
return value;
|
||
}
|
||
|
||
/* Install a new variable_buffer context, returning the current one for
|
||
safe-keeping. */
|
||
|
||
void
|
||
install_variable_buffer (char **bufp, unsigned int *lenp)
|
||
{
|
||
*bufp = variable_buffer;
|
||
*lenp = variable_buffer_length;
|
||
|
||
variable_buffer = 0;
|
||
initialize_variable_output ();
|
||
}
|
||
|
||
/* Restore a previously-saved variable_buffer setting (free the current one).
|
||
*/
|
||
|
||
void
|
||
restore_variable_buffer (char *buf, unsigned int len)
|
||
{
|
||
free (variable_buffer);
|
||
|
||
variable_buffer = buf;
|
||
variable_buffer_length = len;
|
||
}
|