1 /* Variable expansion functions for GNU Make.
2 Copyright (C) 1988, 89, 91, 92, 93, 95 Free Software Foundation, Inc.
3 This file is part of GNU Make.
5 GNU Make is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
10 GNU Make is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNU Make; see the file COPYING. If not, write to
17 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
30 /* The next two describe the variable output buffer.
31 This buffer is used to hold the variable-expansion of a line of the
32 makefile. It is made bigger with realloc whenever it is too small.
33 variable_buffer_length is the size currently allocated.
34 variable_buffer is the address of the buffer.
36 For efficiency, it's guaranteed that the buffer will always have
37 VARIABLE_BUFFER_ZONE extra bytes allocated. This allows you to add a few
38 extra chars without having to call a function. Note you should never use
39 these bytes unless you're _sure_ you have room (you know when the buffer
40 length was last checked. */
42 #define VARIABLE_BUFFER_ZONE 5
44 static unsigned int variable_buffer_length
;
45 char *variable_buffer
;
47 /* Subroutine of variable_expand and friends:
48 The text to add is LENGTH chars starting at STRING to the variable_buffer.
49 The text is added to the buffer at PTR, and the updated pointer into
50 the buffer is returned as the value. Thus, the value returned by
51 each call to variable_buffer_output should be the first argument to
52 the following call. */
55 variable_buffer_output (char *ptr
, char *string
, unsigned int length
)
57 register unsigned int newlen
= length
+ (ptr
- variable_buffer
);
59 if ((newlen
+ VARIABLE_BUFFER_ZONE
) > variable_buffer_length
)
61 unsigned int offset
= ptr
- variable_buffer
;
62 variable_buffer_length
= (newlen
+ 100 > 2 * variable_buffer_length
64 : 2 * variable_buffer_length
);
65 variable_buffer
= (char *) xrealloc (variable_buffer
,
66 variable_buffer_length
);
67 ptr
= variable_buffer
+ offset
;
70 bcopy (string
, ptr
, length
);
74 /* Return a pointer to the beginning of the variable buffer. */
77 initialize_variable_output (void)
79 /* If we don't have a variable output buffer yet, get one. */
81 if (variable_buffer
== 0)
83 variable_buffer_length
= 200;
84 variable_buffer
= (char *) xmalloc (variable_buffer_length
);
85 variable_buffer
[0] = '\0';
88 return variable_buffer
;
91 /* Recursively expand V. The returned string is malloc'd. */
93 static char *allocated_variable_append
PARAMS ((const struct variable
*v
));
96 recursively_expand_for_file (struct variable
*v
, struct file
*file
)
99 struct variable_set_list
*save
= 0;
104 /* Expanding V causes infinite recursion. Lose. */
106 _("Recursive variable `%s' references itself (eventually)"),
113 save
= current_variable_set_list
;
114 current_variable_set_list
= file
->variables
;
119 value
= allocated_variable_append (v
);
121 value
= allocated_variable_expand (v
->value
);
125 current_variable_set_list
= save
;
130 /* Expand a simple reference to variable NAME, which is LENGTH chars long. */
136 reference_variable (char *o
, char *name
, unsigned int length
)
138 register struct variable
*v
;
141 v
= lookup_variable (name
, length
);
144 warn_undefined (name
, length
);
146 if (v
== 0 || *v
->value
== '\0')
149 value
= (v
->recursive
? recursively_expand (v
) : v
->value
);
151 o
= variable_buffer_output (o
, value
, strlen (value
));
159 /* Scan STRING for variable references and expansion-function calls. Only
160 LENGTH bytes of STRING are actually scanned. If LENGTH is -1, scan until
161 a null byte is found.
163 Write the results to LINE, which must point into `variable_buffer'. If
164 LINE is NULL, start at the beginning of the buffer.
165 Return a pointer to LINE, or to the beginning of the buffer if LINE is
169 variable_expand_string (char *line
, char *string
, long length
)
171 register struct variable
*v
;
172 register char *p
, *o
, *p1
;
173 char save_char
= '\0';
174 unsigned int line_offset
;
177 line
= initialize_variable_output();
181 line_offset
= line
- variable_buffer
;
185 save_char
= string
[length
];
186 string
[length
] = '\0';
191 /* Copy all following uninteresting chars all at once to the
192 variable output buffer, and skip them. Uninteresting chars end
193 at the next $ or the end of the input. */
195 p1
= strchr (p
, '$');
197 o
= variable_buffer_output (o
, p
, p1
!= 0 ? p1
- p
: strlen (p
) + 1);
203 /* Dispatch on the char that follows the $. */
208 /* $$ seen means output one $ to the variable output buffer. */
209 o
= variable_buffer_output (o
, p
, 1);
214 /* $(...) or ${...} is the general case of substitution. */
217 char closeparen
= (openparen
== '(') ? ')' : '}';
218 register char *beg
= p
+ 1;
225 if (handle_function (&op
, &begp
))
232 /* Is there a variable reference inside the parens or braces?
233 If so, expand it before expanding the entire reference. */
235 end
= strchr (beg
, closeparen
);
237 /* Unterminated variable reference. */
238 fatal (reading_file
, _("unterminated variable reference"));
239 p1
= lindex (beg
, end
, '$');
242 /* BEG now points past the opening paren or brace.
243 Count parens or braces until it is matched. */
245 for (p
= beg
; *p
!= '\0'; ++p
)
249 else if (*p
== closeparen
&& --count
< 0)
252 /* If COUNT is >= 0, there were unmatched opening parens
253 or braces, so we go to the simple case of a variable name
257 beg
= expand_argument (beg
, p
); /* Expand the name. */
258 free_beg
= 1; /* Remember to free BEG when finished. */
259 end
= strchr (beg
, '\0');
263 /* Advance P to the end of this reference. After we are
264 finished expanding this one, P will be incremented to
265 continue the scan. */
268 /* This is not a reference to a built-in function and
269 any variable references inside are now expanded.
270 Is the resultant text a substitution reference? */
272 colon
= lindex (beg
, end
, ':');
275 /* This looks like a substitution reference: $(FOO:A=B). */
276 char *subst_beg
, *subst_end
, *replace_beg
, *replace_end
;
278 subst_beg
= colon
+ 1;
279 subst_end
= lindex (subst_beg
, end
, '=');
281 /* There is no = in sight. Punt on the substitution
282 reference and treat this as a variable name containing
283 a colon, in the code below. */
287 replace_beg
= subst_end
+ 1;
290 /* Extract the variable name before the colon
291 and look up that variable. */
292 v
= lookup_variable (beg
, colon
- beg
);
294 warn_undefined (beg
, colon
- beg
);
296 if (v
!= 0 && *v
->value
!= '\0')
298 char *value
= (v
->recursive
? recursively_expand (v
)
300 char *pattern
, *percent
;
308 pattern
= (char *) alloca (subst_end
- subst_beg
310 bcopy (subst_beg
, pattern
, subst_end
- subst_beg
);
311 pattern
[subst_end
- subst_beg
] = '\0';
313 percent
= find_percent (pattern
);
320 replace
= replace_beg
;
324 replace
= (char *) alloca (replace_end
327 bcopy (replace_beg
, replace
,
328 replace_end
- replace_beg
);
329 replace
[replace_end
- replace_beg
] = '\0';
332 o
= patsubst_expand (o
, value
, pattern
, replace
,
333 percent
, (char *) 0);
336 o
= subst_expand (o
, value
,
337 pattern
, replace_beg
,
348 /* This is an ordinary variable reference.
349 Look up the value of the variable. */
350 o
= reference_variable (o
, beg
, end
- beg
);
361 if (isblank ((unsigned char)p
[-1]))
364 /* A $ followed by a random char is a variable reference:
365 $a is equivalent to $(a). */
367 /* We could do the expanding here, but this way
368 avoids code repetition at a small performance cost. */
375 p1
= allocated_variable_expand (name
);
376 o
= variable_buffer_output (o
, p1
, strlen (p1
));
390 string
[length
] = save_char
;
392 (void)variable_buffer_output (o
, "", 1);
393 return (variable_buffer
+ line_offset
);
396 /* Scan LINE for variable references and expansion-function calls.
397 Build in `variable_buffer' the result of expanding the references and calls.
398 Return the address of the resulting string, which is null-terminated
399 and is valid only until the next time this function is called. */
402 variable_expand (char *line
)
404 return variable_expand_string(NULL
, line
, (long)-1);
407 /* Expand an argument for an expansion function.
408 The text starting at STR and ending at END is variable-expanded
409 into a null-terminated string that is returned as the value.
410 This is done without clobbering `variable_buffer' or the current
411 variable-expansion that is in progress. */
414 expand_argument (const char *str
, const char *end
)
421 if (!end
|| *end
== '\0')
422 return allocated_variable_expand ((char *)str
);
424 tmp
= (char *) alloca (end
- str
+ 1);
425 bcopy (str
, tmp
, end
- str
);
426 tmp
[end
- str
] = '\0';
428 return allocated_variable_expand (tmp
);
431 /* Expand LINE for FILE. Error messages refer to the file and line where
432 FILE's commands were found. Expansion uses FILE's variable set list. */
435 variable_expand_for_file (char *line
, struct file
*file
)
438 struct variable_set_list
*save
;
441 return variable_expand (line
);
443 save
= current_variable_set_list
;
444 current_variable_set_list
= file
->variables
;
445 if (file
->cmds
&& file
->cmds
->fileinfo
.filenm
)
446 reading_file
= &file
->cmds
->fileinfo
;
449 result
= variable_expand (line
);
450 current_variable_set_list
= save
;
456 /* Like allocated_variable_expand, but for += target-specific variables.
457 First recursively construct the variable value from its appended parts in
458 any upper variable sets. Then expand the resulting value. */
461 variable_append (const char *name
, unsigned int length
,
462 const struct variable_set_list
*set
)
464 const struct variable
*v
;
467 /* If there's nothing left to check, return the empty buffer. */
469 return initialize_variable_output ();
471 /* Try to find the variable in this variable set. */
472 v
= lookup_variable_in_set (name
, length
, set
->set
);
474 /* If there isn't one, look to see if there's one in a set above us. */
476 return variable_append (name
, length
, set
->next
);
478 /* If this variable type is append, first get any upper values.
479 If not, initialize the buffer. */
481 buf
= variable_append (name
, length
, set
->next
);
483 buf
= initialize_variable_output ();
485 /* Append this value to the buffer, and return it.
486 If we already have a value, first add a space. */
487 if (buf
> variable_buffer
)
488 buf
= variable_buffer_output (buf
, " ", 1);
490 return variable_buffer_output (buf
, v
->value
, strlen (v
->value
));
495 allocated_variable_append (const struct variable
*v
)
499 /* Construct the appended variable value. */
501 char *obuf
= variable_buffer
;
502 unsigned int olen
= variable_buffer_length
;
506 val
= variable_append (v
->name
, strlen (v
->name
), current_variable_set_list
);
507 variable_buffer_output (val
, "", 1);
508 val
= variable_buffer
;
510 variable_buffer
= obuf
;
511 variable_buffer_length
= olen
;
513 /* Now expand it and return that. */
515 retval
= allocated_variable_expand (val
);
521 /* Like variable_expand_for_file, but the returned string is malloc'd.
522 This function is called a lot. It wants to be efficient. */
525 allocated_variable_expand_for_file (char *line
, struct file
*file
)
529 char *obuf
= variable_buffer
;
530 unsigned int olen
= variable_buffer_length
;
534 value
= variable_expand_for_file (line
, file
);
537 /* Waste a little memory and save time. */
538 value
= xrealloc (value
, strlen (value
))
541 variable_buffer
= obuf
;
542 variable_buffer_length
= olen
;
547 /* Install a new variable_buffer context, returning the current one for
551 install_variable_buffer (char **bufp
, unsigned int *lenp
)
553 *bufp
= variable_buffer
;
554 *lenp
= variable_buffer_length
;
557 initialize_variable_output ();
560 /* Restore a previously-saved variable_buffer setting (free the current one).
564 restore_variable_buffer (char *buf
, unsigned int len
)
566 free (variable_buffer
);
568 variable_buffer
= buf
;
569 variable_buffer_length
= len
;