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
|
// 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 "graph.h"
#include <assert.h>
#include <stdio.h>
#include "build_log.h"
#include "depfile_parser.h"
#include "disk_interface.h"
#include "explain.h"
#include "manifest_parser.h"
#include "metrics.h"
#include "state.h"
#include "util.h"
bool Node::Stat(DiskInterface* disk_interface) {
METRIC_RECORD("node stat");
mtime_ = disk_interface->Stat(path_);
return mtime_ > 0;
}
bool Edge::RecomputeDirty(State* state, DiskInterface* disk_interface,
string* err) {
bool dirty = false;
outputs_ready_ = true;
if (!rule_->depfile().empty()) {
if (!LoadDepFile(state, disk_interface, err)) {
if (!err->empty())
return false;
EXPLAIN("Edge targets are dirty because depfile '%s' is missing",
EvaluateDepFile().c_str());
dirty = true;
}
}
// Visit all inputs; we're dirty if any of the inputs are dirty.
TimeStamp most_recent_input = 1;
Node* most_recent_node = NULL;
for (vector<Node*>::iterator i = inputs_.begin(); i != inputs_.end(); ++i) {
if ((*i)->StatIfNecessary(disk_interface)) {
if (Edge* edge = (*i)->in_edge()) {
if (!edge->RecomputeDirty(state, disk_interface, err))
return false;
} else {
// This input has no in-edge; it is dirty if it is missing.
if (!(*i)->exists())
EXPLAIN("%s has no in-edge and is missing", (*i)->path().c_str());
(*i)->set_dirty(!(*i)->exists());
}
}
// If an input is not ready, neither are our outputs.
if (Edge* edge = (*i)->in_edge()) {
if (!edge->outputs_ready_)
outputs_ready_ = false;
}
if (!is_order_only(i - inputs_.begin())) {
// If a regular input is dirty (or missing), we're dirty.
// Otherwise consider mtime.
if ((*i)->dirty()) {
EXPLAIN("%s is dirty", (*i)->path().c_str());
dirty = true;
} else {
if ((*i)->mtime() > most_recent_input) {
most_recent_input = (*i)->mtime();
most_recent_node = *i;
}
}
}
}
// We may also be dirty due to output state: missing outputs, out of
// date outputs, etc. Visit all outputs and determine whether they're dirty.
if (!dirty) {
BuildLog* build_log = state ? state->build_log_ : 0;
string command = EvaluateCommand(true);
for (vector<Node*>::iterator i = outputs_.begin();
i != outputs_.end(); ++i) {
(*i)->StatIfNecessary(disk_interface);
if (RecomputeOutputDirty(build_log, most_recent_input, most_recent_node, command, *i)) {
dirty = true;
break;
}
}
}
// Finally, visit each output to mark off that we've visited it, and update
// their dirty state if necessary.
for (vector<Node*>::iterator i = outputs_.begin(); i != outputs_.end(); ++i) {
(*i)->StatIfNecessary(disk_interface);
if (dirty)
(*i)->MarkDirty();
}
// If we're dirty, our outputs are normally not ready. (It's possible to be
// clean but still not be ready in the presence of order-only inputs.)
// But phony edges with no inputs have nothing to do, so are always ready.
if (dirty && !(is_phony() && inputs_.empty()))
outputs_ready_ = false;
return true;
}
bool Edge::RecomputeOutputDirty(BuildLog* build_log,
TimeStamp most_recent_input,
Node* most_recent_node,
const string& command,
Node* output) {
if (is_phony()) {
// Phony edges don't write any output. Outputs are only dirty if
// there are no inputs and we're missing the output.
return inputs_.empty() && !output->exists();
}
BuildLog::LogEntry* entry = 0;
// Dirty if we're missing the output.
if (!output->exists()) {
EXPLAIN("output %s doesn't exist", output->path().c_str());
return true;
}
// Dirty if the output is older than the input.
if (output->mtime() < most_recent_input) {
// If this is a restat rule, we may have cleaned the output with a restat
// rule in a previous run and stored the most recent input mtime in the
// build log. Use that mtime instead, so that the file will only be
// considered dirty if an input was modified since the previous run.
if (rule_->restat() && build_log &&
(entry = build_log->LookupByOutput(output->path()))) {
if (entry->restat_mtime < most_recent_input) {
EXPLAIN("restat of output %s older than most recent input %s (%d vs %d)",
output->path().c_str(),
most_recent_node ? most_recent_node->path().c_str() : "",
entry->restat_mtime, most_recent_input);
return true;
}
} else {
EXPLAIN("output %s older than most recent input %s (%d vs %d)",
output->path().c_str(),
most_recent_node ? most_recent_node->path().c_str() : "",
output->mtime(), most_recent_input);
return true;
}
}
// May also be dirty due to the command changing since the last build.
// But if this is a generator rule, the command changing does not make us
// dirty.
if (!rule_->generator() && build_log) {
if (entry || (entry = build_log->LookupByOutput(output->path()))) {
if (BuildLog::LogEntry::HashCommand(command) != entry->command_hash) {
EXPLAIN("command line changed for %s", output->path().c_str());
return true;
}
}
if (!entry) {
EXPLAIN("command line not found in log for %s", output->path().c_str());
return true;
}
}
return false;
}
bool Edge::AllInputsReady() const {
for (vector<Node*>::const_iterator i = inputs_.begin();
i != inputs_.end(); ++i) {
if ((*i)->in_edge() && !(*i)->in_edge()->outputs_ready())
return false;
}
return true;
}
/// An Env for an Edge, providing $in and $out.
struct EdgeEnv : public Env {
explicit EdgeEnv(Edge* edge) : edge_(edge) {}
virtual string LookupVariable(const string& var);
/// Given a span of Nodes, construct a list of paths suitable for a command
/// line. XXX here is where shell-escaping of e.g spaces should happen.
string MakePathList(vector<Node*>::iterator begin,
vector<Node*>::iterator end,
char sep);
Edge* edge_;
};
string EdgeEnv::LookupVariable(const string& var) {
if (var == "in" || var == "in_newline") {
int explicit_deps_count = edge_->inputs_.size() - edge_->implicit_deps_ -
edge_->order_only_deps_;
return MakePathList(edge_->inputs_.begin(),
edge_->inputs_.begin() + explicit_deps_count,
var == "in" ? ' ' : '\n');
} else if (var == "out") {
return MakePathList(edge_->outputs_.begin(),
edge_->outputs_.end(),
' ');
} else if (edge_->env_) {
return edge_->env_->LookupVariable(var);
} else {
// XXX should we warn here?
return string();
}
}
string EdgeEnv::MakePathList(vector<Node*>::iterator begin,
vector<Node*>::iterator end,
char sep) {
string result;
for (vector<Node*>::iterator i = begin; i != end; ++i) {
if (!result.empty())
result.push_back(sep);
const string& path = (*i)->path();
if (path.find(" ") != string::npos) {
result.append("\"");
result.append(path);
result.append("\"");
} else {
result.append(path);
}
}
return result;
}
string Edge::EvaluateCommand(bool incl_rsp_file) {
EdgeEnv env(this);
string command = rule_->command().Evaluate(&env);
if (incl_rsp_file && HasRspFile())
command += ";rspfile=" + GetRspFileContent();
return command;
}
string Edge::EvaluateDepFile() {
EdgeEnv env(this);
return rule_->depfile().Evaluate(&env);
}
string Edge::GetDescription() {
EdgeEnv env(this);
return rule_->description().Evaluate(&env);
}
bool Edge::HasRspFile() {
return !rule_->rspfile().empty();
}
string Edge::GetRspFile() {
EdgeEnv env(this);
return rule_->rspfile().Evaluate(&env);
}
string Edge::GetRspFileContent() {
EdgeEnv env(this);
return rule_->rspfile_content().Evaluate(&env);
}
bool Edge::LoadDepFile(State* state, DiskInterface* disk_interface,
string* err) {
METRIC_RECORD("depfile load");
string path = EvaluateDepFile();
string content = disk_interface->ReadFile(path, err);
if (!err->empty())
return false;
// On a missing depfile: return false and empty *err.
if (content.empty())
return false;
DepfileParser depfile;
string depfile_err;
if (!depfile.Parse(&content, &depfile_err)) {
*err = path + ": " + depfile_err;
return false;
}
// Check that this depfile matches our output.
StringPiece opath = StringPiece(outputs_[0]->path());
if (opath != depfile.out_) {
*err = "expected depfile '" + path + "' to mention '" +
outputs_[0]->path() + "', got '" + depfile.out_.AsString() + "'";
return false;
}
inputs_.insert(inputs_.end() - order_only_deps_, depfile.ins_.size(), 0);
implicit_deps_ += depfile.ins_.size();
vector<Node*>::iterator implicit_dep =
inputs_.end() - order_only_deps_ - depfile.ins_.size();
// Add all its in-edges.
for (vector<StringPiece>::iterator i = depfile.ins_.begin();
i != depfile.ins_.end(); ++i, ++implicit_dep) {
if (!CanonicalizePath(const_cast<char*>(i->str_), &i->len_, err))
return false;
Node* node = state->GetNode(*i);
*implicit_dep = node;
node->AddOutEdge(this);
// If we don't have a edge that generates this input already,
// create one; this makes us not abort if the input is missing,
// but instead will rebuild in that circumstance.
if (!node->in_edge()) {
Edge* phony_edge = state->AddEdge(&State::kPhonyRule);
node->set_in_edge(phony_edge);
phony_edge->outputs_.push_back(node);
// RecomputeDirty might not be called for phony_edge if a previous call
// to RecomputeDirty had caused the file to be stat'ed. Because previous
// invocations of RecomputeDirty would have seen this node without an
// input edge (and therefore ready), we have to set outputs_ready_ to true
// to avoid a potential stuck build. If we do call RecomputeDirty for
// this node, it will simply set outputs_ready_ to the correct value.
phony_edge->outputs_ready_ = true;
}
}
return true;
}
void Edge::Dump(const char* prefix) const {
printf("%s[ ", prefix);
for (vector<Node*>::const_iterator i = inputs_.begin();
i != inputs_.end() && *i != NULL; ++i) {
printf("%s ", (*i)->path().c_str());
}
printf("--%s-> ", rule_->name().c_str());
for (vector<Node*>::const_iterator i = outputs_.begin();
i != outputs_.end() && *i != NULL; ++i) {
printf("%s ", (*i)->path().c_str());
}
printf("] 0x%p\n", this);
}
bool Edge::is_phony() const {
return rule_ == &State::kPhonyRule;
}
void Node::Dump(const char* prefix) const {
printf("%s <%s 0x%p> mtime: %d%s, (:%s), ",
prefix, path().c_str(), this,
mtime(), mtime()?"":" (:missing)",
dirty()?" dirty":" clean");
if (in_edge()) {
in_edge()->Dump("in-edge: ");
}else{
printf("no in-edge\n");
}
printf(" out edges:\n");
for (vector<Edge*>::const_iterator e = out_edges().begin();
e != out_edges().end() && *e != NULL; ++e) {
(*e)->Dump(" +- ");
}
}
|