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
|
// Copyright 2014 The Bazel Authors. 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.
package com.google.devtools.build.lib.skyframe;
import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.concurrent.Uninterruptibles;
import com.google.devtools.build.lib.events.Event;
import com.google.devtools.build.lib.events.ExtendedEventHandler;
import com.google.devtools.build.lib.packages.NoSuchPackageException;
import com.google.devtools.build.lib.packages.NoSuchTargetException;
import com.google.devtools.build.lib.packages.NoSuchThingException;
import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.pkgcache.PackageProvider;
import com.google.devtools.build.skyframe.CycleInfo;
import com.google.devtools.build.skyframe.CyclesReporter;
import com.google.devtools.build.skyframe.SkyKey;
import java.util.concurrent.Callable;
/** Reports cycles between skyframe values whose keys contains {@link Label}s. */
abstract class AbstractLabelCycleReporter implements CyclesReporter.SingleCycleReporter {
private final PackageProvider packageProvider;
AbstractLabelCycleReporter(PackageProvider packageProvider) {
this.packageProvider = packageProvider;
}
/** Returns the String representation of the {@code SkyKey}. */
protected abstract String prettyPrint(SkyKey key);
/** Returns the associated Label of the SkyKey. */
protected abstract Label getLabel(SkyKey key);
protected abstract boolean canReportCycle(SkyKey topLevelKey, CycleInfo cycleInfo);
/**
* Can be used to skip individual keys on the path to cycle.
*
* @param key
*/
protected boolean shouldSkip(SkyKey key) {
return false;
}
/**
* Can be used to report an additional message about the cycle.
*
* @param eventHandler
* @param topLevelKey
* @param cycleInfo
*/
protected String getAdditionalMessageAboutCycle(
ExtendedEventHandler eventHandler, SkyKey topLevelKey, CycleInfo cycleInfo) {
return "";
}
@Override
public boolean maybeReportCycle(
SkyKey topLevelKey,
CycleInfo cycleInfo,
boolean alreadyReported,
ExtendedEventHandler eventHandler) {
Preconditions.checkNotNull(eventHandler);
if (!canReportCycle(topLevelKey, cycleInfo)) {
return false;
}
if (alreadyReported) {
Label label = getLabel(topLevelKey);
Target target = getTargetForLabel(eventHandler, label);
eventHandler.handle(Event.error(target.getLocation(),
"in " + target.getTargetKind() + " " + label +
": cycle in dependency graph: target depends on an already-reported cycle"));
} else {
StringBuilder cycleMessage = new StringBuilder("cycle in dependency graph:");
ImmutableList<SkyKey> pathToCycle = cycleInfo.getPathToCycle();
ImmutableList<SkyKey> cycle = cycleInfo.getCycle();
for (SkyKey value : pathToCycle) {
if (shouldSkip(value)) {
continue;
}
cycleMessage.append("\n ");
cycleMessage.append(prettyPrint(value));
}
SkyKey cycleValue = printCycle(cycle, cycleMessage, new Function<SkyKey, String>() {
@Override
public String apply(SkyKey input) {
return prettyPrint(input);
}
});
cycleMessage.append(getAdditionalMessageAboutCycle(eventHandler, topLevelKey, cycleInfo));
Label label = getLabel(cycleValue);
Target target = getTargetForLabel(eventHandler, label);
eventHandler.handle(Event.error(
target.getLocation(),
"in " + target.getTargetKind() + " " + label + ": " + cycleMessage));
}
return true;
}
/**
* Prints the SkyKey-s in cycle into cycleMessage using the print function.
*/
static SkyKey printCycle(ImmutableList<SkyKey> cycle, StringBuilder cycleMessage,
Function<SkyKey, String> printFunction) {
Iterable<SkyKey> valuesToPrint = cycle.size() > 1
? Iterables.concat(cycle, ImmutableList.of(cycle.get(0))) : cycle;
SkyKey cycleValue = null;
for (SkyKey value : valuesToPrint) {
if (cycleValue == null) { // first item
cycleValue = value;
cycleMessage.append("\n.-> ");
} else {
if (value == cycleValue) { // last item of the cycle
cycleMessage.append("\n`-- ");
} else {
cycleMessage.append("\n| ");
}
}
cycleMessage.append(printFunction.apply(value));
}
if (cycle.size() == 1) {
cycleMessage.append(" [self-edge]");
cycleMessage.append("\n`--");
}
return cycleValue;
}
protected final Target getTargetForLabel(
final ExtendedEventHandler eventHandler, final Label label) {
try {
return Uninterruptibles.callUninterruptibly(new Callable<Target>() {
@Override
public Target call()
throws NoSuchPackageException, NoSuchTargetException, InterruptedException {
return packageProvider.getTarget(eventHandler, label);
}
});
} catch (NoSuchThingException e) {
// This method is used for getting the target from a label in a circular dependency.
// If we have a cycle that means that we need to have accessed the target (to get its
// dependencies). So all the labels in a dependency cycle need to exist.
throw new IllegalStateException(e);
} catch (Exception e) {
throw new IllegalStateException(e);
}
}
}
|
