summaryrefslogtreecommitdiffstats
path: root/src/ninja.cc
blob: d7248ac90c1862bed83c25443b34222fd5631d2a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
// Copyright 2011 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>

#ifdef _WIN32
#include "getopt.h"
#include <direct.h>
#include <windows.h>
#else
#include <getopt.h>
#include <unistd.h>
#endif

#include "browse.h"
#include "build.h"
#include "build_log.h"
#include "clean.h"
#include "disk_interface.h"
#include "edit_distance.h"
#include "explain.h"
#include "graph.h"
#include "graphviz.h"
#include "manifest_parser.h"
#include "metrics.h"
#include "state.h"
#include "util.h"

namespace {

/// The version number of the current Ninja release.  This will always
/// be "git" on trunk.
const char* kVersion = "git";

/// Global information passed into subtools.
struct Globals {
  Globals() : state(new State()) {}
  ~Globals() {
    delete state;
  }

  /// Deletes and recreates state so it is empty.
  void ResetState() {
    delete state;
    state = new State();
  }

  /// Command line used to run Ninja.
  const char* ninja_command;
  /// Build configuration (e.g. parallelism).
  BuildConfig config;
  /// Loaded state (rules, nodes). This is a pointer so it can be reset.
  State* state;
};

/// Print usage information.
void Usage(const BuildConfig& config) {
  fprintf(stderr,
"usage: ninja [options] [targets...]\n"
"\n"
"if targets are unspecified, builds the 'default' target (see manual).\n"
"\n"
"options:\n"
"  --version  print ninja version (\"%s\")\n"
"\n"
"  -C DIR   change to DIR before doing anything else\n"
"  -f FILE  specify input build file [default=build.ninja]\n"
"\n"
"  -j N     run N jobs in parallel [default=%d]\n"
"  -l N     do not start new jobs if the load average is greater than N\n"
#ifdef _WIN32
"           (not yet implemented on Windows)\n"
#endif
"  -k N     keep going until N jobs fail [default=1]\n"
"  -n       dry run (don't run commands but act like they succeeded)\n"
"  -v       show all command lines while building\n"
"\n"
"  -d MODE  enable debugging (use -d list to list modes)\n"
"  -t TOOL  run a subtool (use -t list to list subtools)\n"
"    terminates toplevel options; further flags are passed to the tool\n",
          kVersion, config.parallelism);
}

/// Choose a default value for the -j (parallelism) flag.
int GuessParallelism() {
  switch (int processors = GetProcessorCount()) {
  case 0:
  case 1:
    return 2;
  case 2:
    return 3;
  default:
    return processors + 2;
  }
}

/// An implementation of ManifestParser::FileReader that actually reads
/// the file.
struct RealFileReader : public ManifestParser::FileReader {
  bool ReadFile(const string& path, string* content, string* err) {
    return ::ReadFile(path, content, err) == 0;
  }
};

/// Rebuild the build manifest, if necessary.
/// Returns true if the manifest was rebuilt.
bool RebuildManifest(Builder* builder, const char* input_file, string* err) {
  string path = input_file;
  if (!CanonicalizePath(&path, err))
    return false;
  Node* node = builder->state_->LookupNode(path);
  if (!node)
    return false;

  if (!builder->AddTarget(node, err))
    return false;

  if (builder->AlreadyUpToDate())
    return false;  // Not an error, but we didn't rebuild.
  if (!builder->Build(err))
    return false;

  // The manifest was only rebuilt if it is now dirty (it may have been cleaned
  // by a restat).
  return node->dirty();
}

bool CollectTargetsFromArgs(State* state, int argc, char* argv[],
                            vector<Node*>* targets, string* err) {
  if (argc == 0) {
    *targets = state->DefaultNodes(err);
    if (!err->empty())
      return false;
  } else {
    for (int i = 0; i < argc; ++i) {
      string path = argv[i];
      if (!CanonicalizePath(&path, err))
        return false;

      // Special syntax: "foo.cc^" means "the first output of foo.cc".
      bool first_dependent = false;
      if (!path.empty() && path[path.size() - 1] == '^') {
        path.resize(path.size() - 1);
        first_dependent = true;
      }

      Node* node = state->LookupNode(path);
      if (node) {
        if (first_dependent) {
          if (node->out_edges().empty()) {
            *err = "'" + path + "' has no out edge";
            return false;
          }
          Edge* edge = node->out_edges()[0];
          if (edge->outputs_.empty()) {
            edge->Dump();
            Fatal("edge has no outputs");
          }
          node = edge->outputs_[0];
        }
        targets->push_back(node);
      } else {
        *err = "unknown target '" + path + "'";

        if (path == "clean") {
          *err += ", did you mean 'ninja -t clean'?";
        } else if (path == "help") {
          *err += ", did you mean 'ninja -h'?";
        } else {
          Node* suggestion = state->SpellcheckNode(path);
          if (suggestion) {
            *err += ", did you mean '" + suggestion->path() + "'?";
          }
        }
        return false;
      }
    }
  }
  return true;
}

int ToolGraph(Globals* globals, int argc, char* argv[]) {
  vector<Node*> nodes;
  string err;
  if (!CollectTargetsFromArgs(globals->state, argc, argv, &nodes, &err)) {
    Error("%s", err.c_str());
    return 1;
  }

  GraphViz graph;
  graph.Start();
  for (vector<Node*>::const_iterator n = nodes.begin(); n != nodes.end(); ++n)
    graph.AddTarget(*n);
  graph.Finish();

  return 0;
}

int ToolQuery(Globals* globals, int argc, char* argv[]) {
  if (argc == 0) {
    Error("expected a target to query");
    return 1;
  }
  for (int i = 0; i < argc; ++i) {
    Node* node = globals->state->LookupNode(argv[i]);
    if (!node) {
      Node* suggestion = globals->state->SpellcheckNode(argv[i]);
      if (suggestion) {
        printf("%s unknown, did you mean %s?\n",
               argv[i], suggestion->path().c_str());
      } else {
        printf("%s unknown\n", argv[i]);
      }
      return 1;
    }

    printf("%s:\n", argv[i]);
    if (Edge* edge = node->in_edge()) {
      printf("  input: %s\n", edge->rule_->name().c_str());
      for (int in = 0; in < (int)edge->inputs_.size(); in++) {
        const char* label = "";
        if (edge->is_implicit(in))
          label = "| ";
        else if (edge->is_order_only(in))
          label = "|| ";
        printf("    %s%s\n", label, edge->inputs_[in]->path().c_str());
      }
    }
    printf("  outputs:\n");
    for (vector<Edge*>::const_iterator edge = node->out_edges().begin();
         edge != node->out_edges().end(); ++edge) {
      for (vector<Node*>::iterator out = (*edge)->outputs_.begin();
           out != (*edge)->outputs_.end(); ++out) {
        printf("    %s\n", (*out)->path().c_str());
      }
    }
  }
  return 0;
}

#if !defined(_WIN32) && !defined(NINJA_BOOTSTRAP)
int ToolBrowse(Globals* globals, int argc, char* argv[]) {
  if (argc < 1) {
    Error("expected a target to browse");
    return 1;
  }
  RunBrowsePython(globals->state, globals->ninja_command, argv[0]);
  // If we get here, the browse failed.
  return 1;
}
#endif  // _WIN32

int ToolTargetsList(const vector<Node*>& nodes, int depth, int indent) {
  for (vector<Node*>::const_iterator n = nodes.begin();
       n != nodes.end();
       ++n) {
    for (int i = 0; i < indent; ++i)
      printf("  ");
    const char* target = (*n)->path().c_str();
    if ((*n)->in_edge()) {
      printf("%s: %s\n", target, (*n)->in_edge()->rule_->name().c_str());
      if (depth > 1 || depth <= 0)
        ToolTargetsList((*n)->in_edge()->inputs_, depth - 1, indent + 1);
    } else {
      printf("%s\n", target);
    }
  }
  return 0;
}

int ToolTargetsSourceList(State* state) {
  for (vector<Edge*>::iterator e = state->edges_.begin();
       e != state->edges_.end(); ++e) {
    for (vector<Node*>::iterator inps = (*e)->inputs_.begin();
         inps != (*e)->inputs_.end(); ++inps) {
      if (!(*inps)->in_edge())
        printf("%s\n", (*inps)->path().c_str());
    }
  }
  return 0;
}

int ToolTargetsList(State* state, const string& rule_name) {
  set<string> rules;

  // Gather the outputs.
  for (vector<Edge*>::iterator e = state->edges_.begin();
       e != state->edges_.end(); ++e) {
    if ((*e)->rule_->name() == rule_name) {
      for (vector<Node*>::iterator out_node = (*e)->outputs_.begin();
           out_node != (*e)->outputs_.end(); ++out_node) {
        rules.insert((*out_node)->path());
      }
    }
  }

  // Print them.
  for (set<string>::const_iterator i = rules.begin();
       i != rules.end(); ++i) {
    printf("%s\n", (*i).c_str());
  }

  return 0;
}

int ToolTargetsList(State* state) {
  for (vector<Edge*>::iterator e = state->edges_.begin();
       e != state->edges_.end(); ++e) {
    for (vector<Node*>::iterator out_node = (*e)->outputs_.begin();
         out_node != (*e)->outputs_.end(); ++out_node) {
      printf("%s: %s\n",
             (*out_node)->path().c_str(),
             (*e)->rule_->name().c_str());
    }
  }
  return 0;
}

int ToolTargets(Globals* globals, int argc, char* argv[]) {
  int depth = 1;
  if (argc >= 1) {
    string mode = argv[0];
    if (mode == "rule") {
      string rule;
      if (argc > 1)
        rule = argv[1];
      if (rule.empty())
        return ToolTargetsSourceList(globals->state);
      else
        return ToolTargetsList(globals->state, rule);
    } else if (mode == "depth") {
      if (argc > 1)
        depth = atoi(argv[1]);
    } else if (mode == "all") {
      return ToolTargetsList(globals->state);
    } else {
      const char* suggestion =
          SpellcheckString(mode, "rule", "depth", "all", NULL);
      if (suggestion) {
        Error("unknown target tool mode '%s', did you mean '%s'?",
              mode.c_str(), suggestion);
      } else {
        Error("unknown target tool mode '%s'", mode.c_str());
      }
      return 1;
    }
  }

  string err;
  vector<Node*> root_nodes = globals->state->RootNodes(&err);
  if (err.empty()) {
    return ToolTargetsList(root_nodes, depth, 0);
  } else {
    Error("%s", err.c_str());
    return 1;
  }
}

int ToolRules(Globals* globals, int argc, char* /* argv */[]) {
  for (map<string, const Rule*>::iterator i = globals->state->rules_.begin();
       i != globals->state->rules_.end(); ++i) {
    if (i->second->description().empty()) {
      printf("%s\n", i->first.c_str());
    } else {
      printf("%s: %s\n",
             i->first.c_str(),
             // XXX I changed it such that we don't have an easy way
             // to get the source text anymore, so this output is
             // unsatisfactory.  How useful is this command, anyway?
             i->second->description().Serialize().c_str());
    }
  }
  return 0;
}

void PrintCommands(Edge* edge, set<Edge*>* seen) {
  if (!edge)
    return;
  if (!seen->insert(edge).second)
    return;

  for (vector<Node*>::iterator in = edge->inputs_.begin();
       in != edge->inputs_.end(); ++in)
    PrintCommands((*in)->in_edge(), seen);

  if (!edge->is_phony())
    puts(edge->EvaluateCommand().c_str());
}

int ToolCommands(Globals* globals, int argc, char* argv[]) {
  vector<Node*> nodes;
  string err;
  if (!CollectTargetsFromArgs(globals->state, argc, argv, &nodes, &err)) {
    Error("%s", err.c_str());
    return 1;
  }

  set<Edge*> seen;
  for (vector<Node*>::iterator in = nodes.begin(); in != nodes.end(); ++in)
    PrintCommands((*in)->in_edge(), &seen);

  return 0;
}

int ToolClean(Globals* globals, int argc, char* argv[]) {
  // The clean tool uses getopt, and expects argv[0] to contain the name of
  // the tool, i.e. "clean".
  argc++;
  argv--;

  bool generator = false;
  bool clean_rules = false;

  optind = 1;
  int opt;
  while ((opt = getopt(argc, argv, const_cast<char*>("hgr"))) != -1) {
    switch (opt) {
    case 'g':
      generator = true;
      break;
    case 'r':
      clean_rules = true;
      break;
    case 'h':
    default:
      printf("usage: ninja -t clean [options] [targets]\n"
"\n"
"options:\n"
"  -g     also clean files marked as ninja generator output\n"
"  -r     interpret targets as a list of rules to clean instead\n"
             );
    return 1;
    }
  }
  argv += optind;
  argc -= optind;

  if (clean_rules && argc == 0) {
    Error("expected a rule to clean");
    return 1;
  }

  Cleaner cleaner(globals->state, globals->config);
  if (argc >= 1) {
    if (clean_rules)
      return cleaner.CleanRules(argc, argv);
    else
      return cleaner.CleanTargets(argc, argv);
  } else {
    return cleaner.CleanAll(generator);
  }
}

void ToolUrtle() {
  // RLE encoded.
  const char* urtle =
" 13 ,3;2!2;\n8 ,;<11!;\n5 `'<10!(2`'2!\n11 ,6;, `\\. `\\9 .,c13$ec,.\n6 "
",2;11!>; `. ,;!2> .e8$2\".2 \"?7$e.\n <:<8!'` 2.3,.2` ,3!' ;,(?7\";2!2'<"
"; `?6$PF ,;,\n2 `'4!8;<!3'`2 3! ;,`'2`2'3!;4!`2.`!;2 3,2 .<!2'`).\n5 3`5"
"'2`9 `!2 `4!><3;5! J2$b,`!>;2!:2!`,d?b`!>\n26 `'-;,(<9!> $F3 )3.:!.2 d\""
"2 ) !>\n30 7`2'<3!- \"=-='5 .2 `2-=\",!>\n25 .ze9$er2 .,cd16$bc.'\n22 .e"
"14$,26$.\n21 z45$c .\n20 J50$c\n20 14$P\"`?34$b\n20 14$ dbc `2\"?22$?7$c"
"\n20 ?18$c.6 4\"8?4\" c8$P\n9 .2,.8 \"20$c.3 ._14 J9$\n .2,2c9$bec,.2 `?"
"21$c.3`4%,3%,3 c8$P\"\n22$c2 2\"?21$bc2,.2` .2,c7$P2\",cb\n23$b bc,.2\"2"
"?14$2F2\"5?2\",J5$P\" ,zd3$\n24$ ?$3?%3 `2\"2?12$bcucd3$P3\"2 2=7$\n23$P"
"\" ,3;<5!>2;,. `4\"6?2\"2 ,9;, `\"?2$\n";
  int count = 0;
  for (const char* p = urtle; *p; p++) {
    if ('0' <= *p && *p <= '9') {
      count = count*10 + *p - '0';
    } else {
      for (int i = 0; i < std::max(count, 1); ++i)
        printf("%c", *p);
      count = 0;
    }
  }
}

int RunTool(const string& tool, Globals* globals, int argc, char** argv) {
  typedef int (*ToolFunc)(Globals*, int, char**);
  struct Tool {
    const char* name;
    const char* desc;
    ToolFunc func;
  } tools[] = {
#if !defined(_WIN32) && !defined(NINJA_BOOTSTRAP)
    { "browse", "browse dependency graph in a web browser",
      ToolBrowse },
#endif
    { "clean", "clean built files",
      ToolClean },
    { "commands", "list all commands required to rebuild given targets",
      ToolCommands },
    { "graph", "output graphviz dot file for targets",
      ToolGraph },
    { "query", "show inputs/outputs for a path",
      ToolQuery },
    { "rules",    "list all rules",
      ToolRules },
    { "targets",  "list targets by their rule or depth in the DAG",
      ToolTargets },
    { NULL, NULL, NULL }
  };

  if (tool == "list") {
    printf("ninja subtools:\n");
    for (int i = 0; tools[i].name; ++i) {
      printf("%10s  %s\n", tools[i].name, tools[i].desc);
    }
    return 0;
  } else if (tool == "urtle") {
    ToolUrtle();
    return 0;
  }

  for (int i = 0; tools[i].name; ++i) {
    if (tool == tools[i].name)
      return tools[i].func(globals, argc, argv);
  }

  vector<const char*> words;
  for (int i = 0; tools[i].name; ++i)
    words.push_back(tools[i].name);
  const char* suggestion = SpellcheckStringV(tool, words);
  if (suggestion) {
    Error("unknown tool '%s', did you mean '%s'?", tool.c_str(), suggestion);
  } else {
    Error("unknown tool '%s'", tool.c_str());
  }
  return 1;
}

/// Enable a debugging mode.  Returns false if Ninja should exit instead
/// of continuing.
bool DebugEnable(const string& name, Globals* globals) {
  if (name == "list") {
    printf("debugging modes:\n"
"  stats    print operation counts/timing info\n"
"  explain  explain what caused a command to execute\n"
"multiple modes can be enabled via -d FOO -d BAR\n");
    return false;
  } else if (name == "stats") {
    g_metrics = new Metrics;
    return true;
  } else if (name == "explain") {
    g_explaining = true;
    return true;
  } else {
    printf("ninja: unknown debug setting '%s'\n", name.c_str());
    return false;
  }
}

int RunBuild(Builder* builder, int argc, char** argv) {
  string err;
  vector<Node*> targets;
  if (!CollectTargetsFromArgs(builder->state_, argc, argv, &targets, &err)) {
    Error("%s", err.c_str());
    return 1;
  }

  for (size_t i = 0; i < targets.size(); ++i) {
    if (!builder->AddTarget(targets[i], &err)) {
      if (!err.empty()) {
        Error("%s", err.c_str());
        return 1;
      } else {
        // Added a target that is already up-to-date; not really
        // an error.
      }
    }
  }

  if (builder->AlreadyUpToDate()) {
    printf("ninja: no work to do.\n");
    return 0;
  }

  if (!builder->Build(&err)) {
    printf("ninja: build stopped: %s.\n", err.c_str());
    return 1;
  }

  return 0;
}

#ifdef _MSC_VER

} // anonymous namespace

// Defined in minidump-win32.cc.
void CreateWin32MiniDump(_EXCEPTION_POINTERS* pep);

namespace {

/// This handler processes fatal crashes that you can't catch
/// Test example: C++ exception in a stack-unwind-block
/// Real-world example: ninja launched a compiler to process a tricky
/// C++ input file. The compiler got itself into a state where it
/// generated 3 GB of output and caused ninja to crash.
void TerminateHandler() {
  CreateWin32MiniDump(NULL);
  Fatal("terminate handler called");
}

/// On Windows, we want to prevent error dialogs in case of exceptions.
/// This function handles the exception, and writes a minidump.
int ExceptionFilter(unsigned int code, struct _EXCEPTION_POINTERS *ep) {
  Error("exception: 0x%X", code);  // e.g. EXCEPTION_ACCESS_VIOLATION
  fflush(stderr);
  CreateWin32MiniDump(ep);
  return EXCEPTION_EXECUTE_HANDLER;
}

#endif  // _MSC_VER

int NinjaMain(int argc, char** argv) {
  Globals globals;
  globals.ninja_command = argv[0];
  const char* input_file = "build.ninja";
  const char* working_dir = NULL;
  string tool;

  setvbuf(stdout, NULL, _IOLBF, BUFSIZ);

  globals.config.parallelism = GuessParallelism();

  enum { OPT_VERSION = 1 };
  const option kLongOptions[] = {
    { "help", no_argument, NULL, 'h' },
    { "version", no_argument, NULL, OPT_VERSION },
    { NULL, 0, NULL, 0 }
  };

  int opt;
  while (tool.empty() &&
         (opt = getopt_long(argc, argv, "d:f:hj:k:l:nt:vC:V", kLongOptions,
                            NULL)) != -1) {
    switch (opt) {
      case 'd':
        if (!DebugEnable(optarg, &globals))
          return 1;
        break;
      case 'f':
        input_file = optarg;
        break;
      case 'j':
        globals.config.parallelism = atoi(optarg);
        break;
      case 'l': {
        char* end;
        double value = strtod(optarg, &end);
        if (end == optarg)
          Fatal("-l parameter not numeric: did you mean -l 0.0?");
        globals.config.max_load_average = value;
        break;
      }
      case 'k': {
        char* end;
        int value = strtol(optarg, &end, 10);
        if (*end != 0)
          Fatal("-k parameter not numeric; did you mean -k 0?");

        // We want to go until N jobs fail, which means we should allow
        // N failures and then stop.  For N <= 0, INT_MAX is close enough
        // to infinite for most sane builds.
        globals.config.failures_allowed = value > 0 ? value : INT_MAX;
        break;
      }
      case 'n':
        globals.config.dry_run = true;
        break;
      case 'v':
        globals.config.verbosity = BuildConfig::VERBOSE;
        break;
      case 't':
        tool = optarg;
        break;
      case 'C':
        working_dir = optarg;
        break;
      case OPT_VERSION:
        printf("%s\n", kVersion);
        return 0;
      case 'h':
      default:
        Usage(globals.config);
        return 1;
    }
  }
  argv += optind;
  argc -= optind;

  if (working_dir) {
    // The formatting of this string, complete with funny quotes, is
    // so Emacs can properly identify that the cwd has changed for
    // subsequent commands.
    // Don't print this if a tool is being used, so that tool output
    // can be piped into a file without this string showing up.
    if (tool == "")
      printf("ninja: Entering directory `%s'\n", working_dir);
    if (chdir(working_dir) < 0) {
      Fatal("chdir to '%s' - %s", working_dir, strerror(errno));
    }
  }

  bool rebuilt_manifest = false;

reload:
  RealDiskInterface disk_interface;
  RealFileReader file_reader;
  ManifestParser parser(globals.state, &file_reader);
  string err;
  if (!parser.Load(input_file, &err)) {
    Error("%s", err.c_str());
    return 1;
  }

  if (!tool.empty())
    return RunTool(tool, &globals, argc, argv);

  BuildLog build_log;

  const string build_dir = globals.state->bindings_.LookupVariable("builddir");
  const char* kLogPath = ".ninja_log";
  string log_path = kLogPath;
  if (!build_dir.empty()) {
    log_path = build_dir + "/" + kLogPath;
    if (!disk_interface.MakeDirs(log_path) && errno != EEXIST) {
      Error("creating build directory %s: %s",
            build_dir.c_str(), strerror(errno));
      return 1;
    }
  }

  if (!build_log.Load(log_path, &err)) {
    Error("loading build log %s: %s", log_path.c_str(), err.c_str());
    return 1;
  }
  if (!err.empty()) {
    // Hack: Load() can return a warning via err by returning true.
    Warning("%s", err.c_str());
    err.clear();
  }

  if (!globals.config.dry_run) {
    if (!build_log.OpenForWrite(log_path, &err)) {
      Error("opening build log: %s", err.c_str());
      return 1;
    }
  }

  if (!rebuilt_manifest) { // Don't get caught in an infinite loop by a rebuild
                           // target that is never up to date.
    Builder manifest_builder(globals.state, globals.config, &build_log,
                             &disk_interface);
    if (RebuildManifest(&manifest_builder, input_file, &err)) {
      rebuilt_manifest = true;
      globals.ResetState();
      goto reload;
    } else if (!err.empty()) {
      Error("rebuilding '%s': %s", input_file, err.c_str());
      return 1;
    }
  }

  Builder builder(globals.state, globals.config, &build_log,
                  &disk_interface);
  int result = RunBuild(&builder, argc, argv);
  if (g_metrics) {
    g_metrics->Report();

    printf("\n");
    int count = (int)globals.state->paths_.size();
    int buckets =
#ifdef _MSC_VER
        (int)globals.state->paths_.comp.bucket_size;
#else
        (int)globals.state->paths_.bucket_count();
#endif
    printf("path->node hash load %.2f (%d entries / %d buckets)\n",
           count / (double) buckets, count, buckets);
  }
  return result;
}

}  // anonymous namespace

int main(int argc, char** argv) {
#if !defined(NINJA_BOOTSTRAP) && defined(_MSC_VER)
  // Set a handler to catch crashes not caught by the __try..__except
  // block (e.g. an exception in a stack-unwind-block).
  set_terminate(TerminateHandler);
  __try {
    // Running inside __try ... __except suppresses any Windows error
    // dialogs for errors such as bad_alloc.
    return NinjaMain(argc, argv);
  }
  __except(ExceptionFilter(GetExceptionCode(), GetExceptionInformation())) {
    // Common error situations return exitCode=1. 2 was chosen to
    // indicate a more serious problem.
    return 2;
  }
#else
  return NinjaMain(argc, argv);
#endif
}