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
|
// Copyright 2014 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.
package com.google.devtools.build.lib.analysis;
import com.google.devtools.build.lib.analysis.config.ConfigurationEnvironment;
import com.google.devtools.build.lib.analysis.config.InvalidConfigurationException;
import com.google.devtools.build.lib.packages.AbstractAttributeMapper;
import com.google.devtools.build.lib.packages.NoSuchPackageException;
import com.google.devtools.build.lib.packages.NoSuchTargetException;
import com.google.devtools.build.lib.packages.Rule;
import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.packages.Type;
import com.google.devtools.build.lib.syntax.Label;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import javax.annotation.Nullable;
/**
* Tool for chasing filegroup redirects. This is mainly intended to be used during
* BuildConfiguration creation.
*/
public final class RedirectChaser {
/**
* Custom attribute mapper that throws an exception if an attribute's value depends on the
* build configuration.
*/
private static class StaticValuedAttributeMapper extends AbstractAttributeMapper {
public StaticValuedAttributeMapper(Rule rule) {
super(rule.getPackage(), rule.getRuleClassObject(), rule.getLabel(),
rule.getAttributeContainer());
}
/**
* Returns the value of the given attribute.
*
* @throws InvalidConfigurationException if the value is configuration-dependent
*/
public <T> T getAndValidate(String attributeName, Type<T> type)
throws InvalidConfigurationException {
if (getSelectorList(attributeName, type) != null) {
throw new InvalidConfigurationException
("The value of '" + attributeName + "' cannot be configuration-dependent");
}
return super.get(attributeName, type);
}
}
/**
* Follows the 'srcs' attribute of the given label recursively. Keeps repeating as long as the
* labels are filegroups with a single srcs entry.
*
* @param env for loading the packages
* @param label the label to start at
* @param name user-meaningful description of the content being resolved
* @return the label which cannot be further resolved
* @throws InvalidConfigurationException if something goes wrong
*/
@Nullable
public static Label followRedirects(ConfigurationEnvironment env, Label label, String name)
throws InvalidConfigurationException {
Set<Label> visitedLabels = new HashSet<>();
visitedLabels.add(label);
try {
while (true) {
Target possibleRedirect = env.getTarget(label);
if (possibleRedirect == null) {
return null;
}
if ((possibleRedirect instanceof Rule) &&
"filegroup".equals(((Rule) possibleRedirect).getRuleClass())) {
List<Label> labels = new StaticValuedAttributeMapper((Rule) possibleRedirect)
.getAndValidate("srcs", Type.LABEL_LIST);
if (labels.size() != 1) {
// We can't distinguish redirects from the final filegroup, so we assume this must be
// the final one.
return label;
}
label = labels.get(0);
if (!visitedLabels.add(label)) {
throw new InvalidConfigurationException("The " + name + " points to a filegroup which "
+ "recursively includes itself. The label " + label + " is part of the loop");
}
} else {
return label;
}
}
} catch (NoSuchPackageException e) {
throw new InvalidConfigurationException(e.getMessage(), e);
} catch (NoSuchTargetException e) {
return label;
}
}
}
|
