1/* Dependency generator for Makefile fragments.
2 Copyright (C) 2000-2024 Free Software Foundation, Inc.
3 Contributed by Zack Weinberg, Mar 2000
4
5This program is free software; you can redistribute it and/or modify it
6under the terms of the GNU General Public License as published by the
7Free Software Foundation; either version 3, or (at your option) any
8later version.
9
10This program is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with this program; see the file COPYING3. If not see
17<http://www.gnu.org/licenses/>.
18
19 In other words, you are welcome to use, share and improve this program.
20 You are forbidden to forbid anyone else to use, share and improve
21 what you give them. Help stamp out software-hoarding! */
22
23#include "config.h"
24#include "system.h"
25#include "mkdeps.h"
26#include "internal.h"
27
28/* Not set up to just include std::vector et al, here's a simple
29 implementation. */
30
31/* Keep this structure local to this file, so clients don't find it
32 easy to start making assumptions. */
33class mkdeps
34{
35public:
36 /* T has trivial cctor & dtor. */
37 template <typename T>
38 class vec
39 {
40 private:
41 T *ary;
42 unsigned num;
43 unsigned alloc;
44
45 public:
46 vec ()
47 : ary (NULL), num (0), alloc (0)
48 {}
49 ~vec ()
50 {
51 XDELETEVEC (ary);
52 }
53
54 public:
55 unsigned size () const
56 {
57 return num;
58 }
59 const T &operator[] (unsigned ix) const
60 {
61 return ary[ix];
62 }
63 T &operator[] (unsigned ix)
64 {
65 return ary[ix];
66 }
67 void push (const T &elt)
68 {
69 if (num == alloc)
70 {
71 alloc = alloc ? alloc * 2 : 16;
72 ary = XRESIZEVEC (T, ary, alloc);
73 }
74 ary[num++] = elt;
75 }
76 };
77 struct velt
78 {
79 const char *str;
80 size_t len;
81 };
82
83 mkdeps ()
84 : primary_output (NULL), module_name (NULL), cmi_name (NULL)
85 , is_header_unit (false), is_exported (false), quote_lwm (0)
86 {
87 }
88 ~mkdeps ()
89 {
90 unsigned int i;
91
92 for (i = targets.size (); i--;)
93 free (ptr: const_cast <char *> (targets[i]));
94 free (ptr: const_cast <char *> (primary_output));
95 for (i = fdeps_targets.size (); i--;)
96 free (ptr: const_cast <char *> (fdeps_targets[i]));
97 for (i = deps.size (); i--;)
98 free (ptr: const_cast <char *> (deps[i]));
99 for (i = vpath.size (); i--;)
100 XDELETEVEC (vpath[i].str);
101 for (i = modules.size (); i--;)
102 XDELETEVEC (modules[i]);
103 XDELETEVEC (module_name);
104 free (ptr: const_cast <char *> (cmi_name));
105 }
106
107public:
108 vec<const char *> targets;
109 vec<const char *> deps;
110 const char * primary_output;
111 vec<const char *> fdeps_targets;
112 vec<velt> vpath;
113 vec<const char *> modules;
114
115public:
116 const char *module_name;
117 const char *cmi_name;
118 bool is_header_unit;
119 bool is_exported;
120 unsigned short quote_lwm;
121};
122
123/* Apply Make quoting to STR, TRAIL. Note that it's not possible to
124 quote all such characters - e.g. \n, %, *, ?, [, \ (in some
125 contexts), and ~ are not properly handled. It isn't possible to
126 get this right in any current version of Make. (??? Still true?
127 Old comment referred to 3.76.1.) */
128
129static const char *
130munge (const char *str, const char *trail = nullptr)
131{
132 static unsigned alloc;
133 static char *buf;
134 unsigned dst = 0;
135
136 for (; str; str = trail, trail = nullptr)
137 {
138 unsigned slashes = 0;
139 char c;
140 for (const char *probe = str; (c = *probe++);)
141 {
142 if (alloc < dst + 4 + slashes)
143 {
144 alloc = alloc * 2 + 32;
145 buf = XRESIZEVEC (char, buf, alloc);
146 }
147
148 switch (c)
149 {
150 case '\\':
151 slashes++;
152 break;
153
154 case '$':
155 buf[dst++] = '$';
156 goto def;
157
158 case ' ':
159 case '\t':
160 /* GNU make uses a weird quoting scheme for white space.
161 A space or tab preceded by 2N+1 backslashes
162 represents N backslashes followed by space; a space
163 or tab preceded by 2N backslashes represents N
164 backslashes at the end of a file name; and
165 backslashes in other contexts should not be
166 doubled. */
167 while (slashes--)
168 buf[dst++] = '\\';
169 /* FALLTHROUGH */
170
171 case '#':
172 buf[dst++] = '\\';
173 /* FALLTHROUGH */
174
175 default:
176 def:
177 slashes = 0;
178 break;
179 }
180
181 buf[dst++] = c;
182 }
183 }
184
185 buf[dst] = 0;
186 return buf;
187}
188
189/* If T begins with any of the partial pathnames listed in d->vpathv,
190 then advance T to point beyond that pathname. */
191static const char *
192apply_vpath (class mkdeps *d, const char *t)
193{
194 if (unsigned len = d->vpath.size ())
195 for (unsigned i = len; i--;)
196 {
197 if (!filename_ncmp (s1: d->vpath[i].str, s2: t, n: d->vpath[i].len))
198 {
199 const char *p = t + d->vpath[i].len;
200 if (!IS_DIR_SEPARATOR (*p))
201 goto not_this_one;
202
203 /* Do not simplify $(vpath)/../whatever. ??? Might not
204 be necessary. */
205 if (p[1] == '.' && p[2] == '.' && IS_DIR_SEPARATOR (p[3]))
206 goto not_this_one;
207
208 /* found a match */
209 t = t + d->vpath[i].len + 1;
210 break;
211 }
212 not_this_one:;
213 }
214
215 /* Remove leading ./ in any case. */
216 while (t[0] == '.' && IS_DIR_SEPARATOR (t[1]))
217 {
218 t += 2;
219 /* If we removed a leading ./, then also remove any /s after the
220 first. */
221 while (IS_DIR_SEPARATOR (t[0]))
222 ++t;
223 }
224
225 return t;
226}
227
228/* Public routines. */
229
230class mkdeps *
231deps_init (void)
232{
233 return new mkdeps ();
234}
235
236void
237deps_free (class mkdeps *d)
238{
239 delete d;
240}
241
242/* Adds a target T. We make a copy, so it need not be a permanent
243 string. QUOTE is true if the string should be quoted. */
244void
245deps_add_target (class mkdeps *d, const char *t, int quote)
246{
247 t = xstrdup (apply_vpath (d, t));
248
249 if (!quote)
250 {
251 /* Sometimes unquoted items are added after quoted ones.
252 Swap out the lowest quoted. */
253 if (d->quote_lwm != d->targets.size ())
254 {
255 const char *lowest = d->targets[d->quote_lwm];
256 d->targets[d->quote_lwm] = t;
257 t = lowest;
258 }
259 d->quote_lwm++;
260 }
261
262 d->targets.push (elt: t);
263}
264
265/* Sets the default target if none has been given already. An empty
266 string as the default target in interpreted as stdin. The string
267 is quoted for MAKE. */
268void
269deps_add_default_target (class mkdeps *d, const char *tgt)
270{
271 /* Only if we have no targets. */
272 if (d->targets.size ())
273 return;
274
275 if (tgt[0] == '\0')
276 d->targets.push (elt: xstrdup ("-"));
277 else
278 {
279#ifndef TARGET_OBJECT_SUFFIX
280# define TARGET_OBJECT_SUFFIX ".o"
281#endif
282 const char *start = lbasename (tgt);
283 char *o = (char *) alloca (strlen (start)
284 + strlen (TARGET_OBJECT_SUFFIX) + 1);
285 char *suffix;
286
287 strcpy (dest: o, src: start);
288
289 suffix = strrchr (s: o, c: '.');
290 if (!suffix)
291 suffix = o + strlen (s: o);
292 strcpy (dest: suffix, TARGET_OBJECT_SUFFIX);
293
294 deps_add_target (d, t: o, quote: 1);
295 }
296}
297
298/* Adds a target O. We make a copy, so it need not be a permanent
299 string.
300
301 This is the target associated with the rule that (in a C++ modules build)
302 compiles the source that is being scanned for dynamic dependencies. It is
303 used to associate the structured dependency information with that rule as
304 needed. */
305void
306fdeps_add_target (struct mkdeps *d, const char *o, bool is_primary)
307{
308 o = apply_vpath (d, t: o);
309 if (is_primary)
310 {
311 if (d->primary_output)
312 d->fdeps_targets.push (elt: d->primary_output);
313 d->primary_output = xstrdup (o);
314 } else
315 d->fdeps_targets.push (elt: xstrdup (o));
316}
317
318void
319deps_add_dep (class mkdeps *d, const char *t)
320{
321 gcc_assert (*t);
322
323 t = apply_vpath (d, t);
324
325 d->deps.push (elt: xstrdup (t));
326}
327
328void
329deps_add_vpath (class mkdeps *d, const char *vpath)
330{
331 const char *elem, *p;
332
333 for (elem = vpath; *elem; elem = p)
334 {
335 for (p = elem; *p && *p != ':'; p++)
336 continue;
337 mkdeps::velt elt;
338 elt.len = p - elem;
339 char *str = XNEWVEC (char, elt.len + 1);
340 elt.str = str;
341 memcpy (dest: str, src: elem, n: elt.len);
342 str[elt.len] = '\0';
343 if (*p == ':')
344 p++;
345
346 d->vpath.push (elt);
347 }
348}
349
350/* Add a new module target (there can only be one). M is the module
351 name. */
352
353void
354deps_add_module_target (struct mkdeps *d, const char *m,
355 const char *cmi, bool is_header_unit, bool is_exported)
356{
357 gcc_assert (!d->module_name);
358
359 d->module_name = xstrdup (m);
360 d->is_header_unit = is_header_unit;
361 d->is_exported = is_exported;
362 d->cmi_name = xstrdup (cmi);
363}
364
365/* Add a new module dependency. M is the module name. */
366
367void
368deps_add_module_dep (struct mkdeps *d, const char *m)
369{
370 d->modules.push (elt: xstrdup (m));
371}
372
373/* Write NAME, with a leading space to FP, a Makefile. Advance COL as
374 appropriate, wrap at COLMAX, returning new column number. Iff
375 QUOTE apply quoting. Append TRAIL. */
376
377static unsigned
378make_write_name (const char *name, FILE *fp, unsigned col, unsigned colmax,
379 bool quote = true, const char *trail = NULL)
380{
381 if (quote)
382 name = munge (str: name, trail);
383 unsigned size = strlen (s: name);
384
385 if (col)
386 {
387 if (colmax && col + size> colmax)
388 {
389 fputs (" \\\n", fp);
390 col = 0;
391 }
392 col++;
393 fputs (" ", fp);
394 }
395
396 col += size;
397 fputs (name, fp);
398
399 return col;
400}
401
402/* Write all the names in VEC via make_write_name. */
403
404static unsigned
405make_write_vec (const mkdeps::vec<const char *> &vec, FILE *fp,
406 unsigned col, unsigned colmax, unsigned quote_lwm = 0,
407 const char *trail = NULL)
408{
409 for (unsigned ix = 0; ix != vec.size (); ix++)
410 col = make_write_name (name: vec[ix], fp, col, colmax, quote: ix >= quote_lwm, trail);
411 return col;
412}
413
414/* Write the dependencies to a Makefile. If PHONY is true, add
415 .PHONY targets for all the dependencies too. */
416
417static void
418make_write (const cpp_reader *pfile, FILE *fp, unsigned int colmax)
419{
420 const mkdeps *d = pfile->deps;
421
422 unsigned column = 0;
423 if (colmax && colmax < 34)
424 colmax = 34;
425
426 /* Write out C++ modules information if no other `-fdeps-format=`
427 option is given. */
428 cpp_fdeps_format fdeps_format = CPP_OPTION (pfile, deps.fdeps_format);
429 bool write_make_modules_deps = (fdeps_format == FDEPS_FMT_NONE
430 && CPP_OPTION (pfile, deps.modules));
431
432 if (d->deps.size ())
433 {
434 column = make_write_vec (vec: d->targets, fp, col: 0, colmax, quote_lwm: d->quote_lwm);
435 if (write_make_modules_deps && d->cmi_name)
436 column = make_write_name (name: d->cmi_name, fp, col: column, colmax);
437 fputs (":", fp);
438 column++;
439 make_write_vec (vec: d->deps, fp, col: column, colmax);
440 fputs ("\n", fp);
441 if (CPP_OPTION (pfile, deps.phony_targets))
442 for (unsigned i = 1; i < d->deps.size (); i++)
443 fprintf (stream: fp, format: "%s:\n", munge (str: d->deps[i]));
444 }
445
446 if (!write_make_modules_deps)
447 return;
448
449 if (d->modules.size ())
450 {
451 column = make_write_vec (vec: d->targets, fp, col: 0, colmax, quote_lwm: d->quote_lwm);
452 if (d->cmi_name)
453 column = make_write_name (name: d->cmi_name, fp, col: column, colmax);
454 fputs (":", fp);
455 column++;
456 column = make_write_vec (vec: d->modules, fp, col: column, colmax, quote_lwm: 0, trail: ".c++m");
457 fputs ("\n", fp);
458 }
459
460 if (d->module_name)
461 {
462 if (d->cmi_name)
463 {
464 /* module-name : cmi-name */
465 column = make_write_name (name: d->module_name, fp, col: 0, colmax,
466 quote: true, trail: ".c++m");
467 fputs (":", fp);
468 column++;
469 column = make_write_name (name: d->cmi_name, fp, col: column, colmax);
470 fputs ("\n", fp);
471
472 column = fprintf (stream: fp, format: ".PHONY:");
473 column = make_write_name (name: d->module_name, fp, col: column, colmax,
474 quote: true, trail: ".c++m");
475 fputs ("\n", fp);
476 }
477
478 if (d->cmi_name && !d->is_header_unit)
479 {
480 /* An order-only dependency.
481 cmi-name :| first-target
482 We can probably drop this this in favour of Make-4.3's grouped
483 targets '&:' */
484 column = make_write_name (name: d->cmi_name, fp, col: 0, colmax);
485 fputs (":|", fp);
486 column++;
487 column = make_write_name (name: d->targets[0], fp, col: column, colmax);
488 fputs ("\n", fp);
489 }
490 }
491
492 if (d->modules.size ())
493 {
494 column = fprintf (stream: fp, format: "CXX_IMPORTS +=");
495 make_write_vec (vec: d->modules, fp, col: column, colmax, quote_lwm: 0, trail: ".c++m");
496 fputs ("\n", fp);
497 }
498}
499
500/* Write out dependencies according to the selected format (which is
501 only Make at the moment). */
502/* Really we should be opening fp here. */
503
504void
505deps_write (const cpp_reader *pfile, FILE *fp, unsigned int colmax)
506{
507 make_write (pfile, fp, colmax);
508}
509
510/* Write out a a filepath for P1689R5 output. */
511
512static void
513p1689r5_write_filepath (const char *name, FILE *fp)
514{
515 if (cpp_valid_utf8_p (data: name, num_bytes: strlen (s: name)))
516 {
517 fputc ('"', fp);
518 for (const char* c = name; *c; c++)
519 {
520 // Escape control characters.
521 if (ISCNTRL (*c))
522 fprintf (stream: fp, format: "\\u%04x", *c);
523 // JSON escape characters.
524 else if (*c == '"' || *c == '\\')
525 {
526 fputc ('\\', fp);
527 fputc (*c, fp);
528 }
529 // Everything else.
530 else
531 fputc (*c, fp);
532 }
533 fputc ('"', fp);
534 }
535 else
536 {
537 // TODO: print an error
538 }
539}
540
541/* Write a JSON array from a `vec` for P1689R5 output.
542
543 In P1689R5, all array values are filepaths. */
544
545static void
546p1689r5_write_vec (const mkdeps::vec<const char *> &vec, FILE *fp)
547{
548 for (unsigned ix = 0; ix != vec.size (); ix++)
549 {
550 p1689r5_write_filepath (name: vec[ix], fp);
551 if (ix < vec.size () - 1)
552 fputc (',', fp);
553 fputc ('\n', fp);
554 }
555}
556
557/* Write out the P1689R5 format using the module dependency tracking
558 information gathered while scanning and/or compiling.
559
560 Ideally this (and the above `p1689r5_` functions) would use `gcc/json.h`,
561 but since this is `libcpp`, we cannot use `gcc/` code.
562
563 TODO: move `json.h` to libiberty. */
564
565void
566deps_write_p1689r5 (const struct mkdeps *d, FILE *fp)
567{
568 fputs ("{\n", fp);
569
570 fputs ("\"rules\": [\n", fp);
571 fputs ("{\n", fp);
572
573 if (d->primary_output)
574 {
575 fputs ("\"primary-output\": ", fp);
576 p1689r5_write_filepath (name: d->primary_output, fp);
577 fputs (",\n", fp);
578 }
579
580 if (d->fdeps_targets.size ())
581 {
582 fputs ("\"outputs\": [\n", fp);
583 p1689r5_write_vec (vec: d->fdeps_targets, fp);
584 fputs ("],\n", fp);
585 }
586
587 if (d->module_name)
588 {
589 fputs ("\"provides\": [\n", fp);
590 fputs ("{\n", fp);
591
592 fputs ("\"logical-name\": ", fp);
593 p1689r5_write_filepath (name: d->module_name, fp);
594 fputs (",\n", fp);
595
596 fprintf (stream: fp, format: "\"is-interface\": %s\n", d->is_exported ? "true" : "false");
597
598 // TODO: header-unit information
599
600 fputs ("}\n", fp);
601 fputs ("],\n", fp);
602 }
603
604 fputs ("\"requires\": [\n", fp);
605 for (size_t i = 0; i < d->modules.size (); i++)
606 {
607 if (i != 0)
608 fputs (",\n", fp);
609 fputs ("{\n", fp);
610
611 fputs ("\"logical-name\": ", fp);
612 p1689r5_write_filepath (name: d->modules[i], fp);
613 fputs ("\n", fp);
614
615 // TODO: header-unit information
616
617 fputs ("}\n", fp);
618 }
619 fputs ("]\n", fp);
620
621 fputs ("}\n", fp);
622
623 fputs ("],\n", fp);
624
625 fputs ("\"version\": 0,\n", fp);
626 fputs ("\"revision\": 0\n", fp);
627
628 fputs ("}\n", fp);
629}
630
631/* Write out a deps buffer to a file, in a form that can be read back
632 with deps_restore. Returns nonzero on error, in which case the
633 error number will be in errno. */
634
635int
636deps_save (class mkdeps *deps, FILE *f)
637{
638 unsigned int i;
639 size_t size;
640
641 /* The cppreader structure contains makefile dependences. Write out this
642 structure. */
643
644 /* The number of dependences. */
645 size = deps->deps.size ();
646 if (fwrite (&size, sizeof (size), 1, f) != 1)
647 return -1;
648
649 /* The length of each dependence followed by the string. */
650 for (i = 0; i < deps->deps.size (); i++)
651 {
652 size = strlen (s: deps->deps[i]);
653 if (fwrite (&size, sizeof (size), 1, f) != 1)
654 return -1;
655 if (fwrite (deps->deps[i], size, 1, f) != 1)
656 return -1;
657 }
658
659 return 0;
660}
661
662/* Read back dependency information written with deps_save into
663 the deps sizefer. The third argument may be NULL, in which case
664 the dependency information is just skipped, or it may be a filename,
665 in which case that filename is skipped. */
666
667int
668deps_restore (class mkdeps *deps, FILE *fd, const char *self)
669{
670 size_t size;
671 char *buf = NULL;
672 size_t buf_size = 0;
673
674 /* Number of dependences. */
675 if (fread (&size, sizeof (size), 1, fd) != 1)
676 return -1;
677
678 /* The length of each dependence string, followed by the string. */
679 for (unsigned i = size; i--;)
680 {
681 /* Read in # bytes in string. */
682 if (fread (&size, sizeof (size), 1, fd) != 1)
683 return -1;
684
685 if (size >= buf_size)
686 {
687 buf_size = size + 512;
688 buf = XRESIZEVEC (char, buf, buf_size);
689 }
690 if (fread (buf, 1, size, fd) != size)
691 {
692 XDELETEVEC (buf);
693 return -1;
694 }
695 buf[size] = 0;
696
697 /* Generate makefile dependencies from .pch if -nopch-deps. */
698 if (self != NULL && filename_cmp (s1: buf, s2: self) != 0)
699 deps_add_dep (d: deps, t: buf);
700 }
701
702 XDELETEVEC (buf);
703 return 0;
704}
705

source code of libcpp/mkdeps.cc