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512 lines
13 KiB
C
512 lines
13 KiB
C
/* Variable expansion functions for GNU Make.
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Copyright (C) 1988, 89, 91, 92, 93, 95 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 "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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/* 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 (ptr, string, length)
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char *ptr, *string;
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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 = (char *) xrealloc (variable_buffer,
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variable_buffer_length);
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ptr = variable_buffer + offset;
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}
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bcopy (string, ptr, 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 ()
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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 = (char *) 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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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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/* Warn that NAME is an undefined variable. */
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#ifdef __GNUC__
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__inline
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#endif
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static void
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warn_undefined (name, length)
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char *name;
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unsigned int length;
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{
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if (warn_undefined_variables_flag)
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{
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static const char warnmsg[] = "warning: undefined variable `%.*s'";
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if (reading_filename != 0)
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makefile_error (reading_filename, *reading_lineno_ptr,
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warnmsg, length, name);
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else
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error (warnmsg, length, name);
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}
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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 (o, name, length)
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char *o;
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char *name;
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unsigned int length;
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{
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register struct variable *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 (v != 0 && *v->value != '\0')
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{
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char *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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}
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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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char *
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variable_expand_string (line, string, length)
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register char *line;
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char *string;
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long length;
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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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char save_char = '\0';
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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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p = string;
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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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save_char = string[length];
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string[length] = '\0';
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}
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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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int free_beg = 0;
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char *op, *begp;
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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 = index (beg, closeparen);
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if (end == 0)
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{
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/* Unterminated variable reference. */
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if (reading_filename != 0)
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makefile_fatal (reading_filename, *reading_lineno_ptr,
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"unterminated variable reference");
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else
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fatal ("unterminated variable reference");
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}
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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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beg = expand_argument (beg, p); /* Expand the name. */
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free_beg = 1; /* Remember to free BEG when finished. */
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end = index (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 != 0)
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{
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/* This looks like a substitution reference: $(FOO:A=B). */
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char *subst_beg, *subst_end, *replace_beg, *replace_end;
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subst_beg = colon + 1;
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subst_end = index (subst_beg, '=');
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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 (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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char *pattern, *percent;
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if (free_beg)
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{
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*subst_end = '\0';
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pattern = subst_beg;
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}
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else
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{
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pattern = (char *) alloca (subst_end - subst_beg
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+ 1);
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bcopy (subst_beg, pattern, subst_end - subst_beg);
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pattern[subst_end - subst_beg] = '\0';
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}
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percent = find_percent (pattern);
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if (percent != 0)
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{
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char *replace;
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if (free_beg)
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{
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*replace_end = '\0';
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replace = replace_beg;
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}
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else
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{
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replace = (char *) alloca (replace_end
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- replace_beg
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+ 1);
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bcopy (replace_beg, replace,
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replace_end - replace_beg);
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replace[replace_end - replace_beg] = '\0';
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}
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o = patsubst_expand (o, value, pattern, replace,
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percent, (char *) 0);
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}
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else
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o = subst_expand (o, value,
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pattern, replace_beg,
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strlen (pattern),
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end - replace_beg,
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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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}
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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 (free_beg)
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free (beg);
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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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if (save_char)
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string[length] = save_char;
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(void)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 (line)
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char *line;
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{
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return variable_expand_string(NULL, line, -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 (str, end)
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char *str, *end;
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{
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char *tmp;
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if (*end == '\0')
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tmp = str;
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else
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{
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tmp = (char *) alloca (end - str + 1);
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bcopy (str, tmp, end - str);
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tmp[end - str] = '\0';
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}
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return allocated_variable_expand (tmp);
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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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static 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, *fnext;
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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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fnext = file->variables->next;
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/* See if there's a pattern-specific variable struct for this target. */
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if (!file->pat_searched)
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{
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file->patvar = lookup_pattern_var(file->name);
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file->pat_searched = 1;
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}
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if (file->patvar != 0)
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{
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file->patvar->vars->next = fnext;
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file->variables->next = file->patvar->vars;
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}
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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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file->variables->next = fnext;
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return result;
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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 *
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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 *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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value = variable_expand_for_file (line, file);
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#if 0
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/* Waste a little memory and save time. */
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value = xrealloc (value, strlen (value))
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#endif
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variable_buffer = obuf;
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variable_buffer_length = olen;
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return value;
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}
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