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
|
// 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.packages;
import com.google.common.collect.ImmutableList;
import com.google.devtools.build.lib.events.Event;
import com.google.devtools.build.lib.packages.PackageFactory.Globber;
import com.google.devtools.build.lib.syntax.Environment;
import com.google.devtools.build.lib.syntax.ParserInputSource;
import com.google.devtools.build.lib.vfs.PathFragment;
import java.io.IOException;
import java.util.List;
import java.util.Set;
import javax.annotation.Nullable;
/** A Preprocessor is an interface to implement generic text-based preprocessing of BUILD files. */
public interface Preprocessor {
/** Factory for {@link Preprocessor} instances. */
interface Factory {
/** Supplier for {@link Factory} instances. */
interface Supplier {
/**
* Returns a Preprocessor factory to use for getting Preprocessor instances.
*
* <p>The CachingPackageLocator is provided so the constructed preprocessors can look up
* other BUILD files.
*/
Factory getFactory(CachingPackageLocator loc);
/** Supplier that always returns {@code NullFactory.INSTANCE}. */
static class NullSupplier implements Supplier {
public static final NullSupplier INSTANCE = new NullSupplier();
private NullSupplier() {
}
@Override
public Factory getFactory(CachingPackageLocator loc) {
return NullFactory.INSTANCE;
}
}
}
/**
* Returns whether this {@link Factory} is still suitable for providing {@link Preprocessor}s.
* If not, all previous preprocessing results should be assumed to be invalid and a new
* {@link Factory} should be created via {@link Supplier#getFactory}.
*/
boolean isStillValid();
/**
* Returns a Preprocessor instance capable of preprocessing a BUILD file independently (e.g. it
* ought to be fine to call {@link #getPreprocessor} for each BUILD file).
*/
@Nullable
Preprocessor getPreprocessor();
/** Factory that always returns {@code null} {@link Preprocessor}s. */
static class NullFactory implements Factory {
public static final NullFactory INSTANCE = new NullFactory();
private NullFactory() {
}
@Override
public boolean isStillValid() {
return true;
}
@Override
public Preprocessor getPreprocessor() {
return null;
}
}
}
/**
* A (result, success) tuple indicating the outcome of preprocessing.
*/
static class Result {
private static final char[] EMPTY_CHARS = new char[0];
public final ParserInputSource result;
public final boolean preprocessed;
public final boolean containsErrors;
public final List<Event> events;
private Result(
ParserInputSource result,
boolean preprocessed,
boolean containsErrors,
List<Event> events) {
this.result = result;
this.preprocessed = preprocessed;
this.containsErrors = containsErrors;
this.events = ImmutableList.copyOf(events);
}
/** Convenience factory for a {@link Result} wrapping non-preprocessed BUILD file contents. */
public static Result noPreprocessing(ParserInputSource buildFileSource) {
return new Result(
buildFileSource,
/*preprocessed=*/ false,
/*containsErrors=*/ false,
ImmutableList.<Event>of());
}
/**
* Factory for a successful preprocessing result, meaning that the BUILD file was able to be
* read and has valid syntax and was preprocessed. But note that there may have been be errors
* during preprocessing.
*/
public static Result success(ParserInputSource result, boolean containsErrors,
List<Event> events) {
return new Result(result, /*preprocessed=*/true, containsErrors, events);
}
public static Result invalidSyntax(PathFragment buildFile, List<Event> events) {
return new Result(
ParserInputSource.create(EMPTY_CHARS, buildFile),
/*preprocessed=*/true,
/*containsErrors=*/true,
events);
}
}
/**
* Returns a Result resulting from applying Python preprocessing to the contents of "in". If
* errors happen, they must be reported both as an event on eventHandler and in the function
* return value. An IOException is only thrown when preparing for preprocessing. Once
* preprocessing actually begins, any I/O problems encountered will be reflected in the return
* value, not manifested as exceptions.
*
* @param in the BUILD file to be preprocessed.
* @param packageName the BUILD file's package.
* @param globber a globber for evaluating globs.
* @param globals the global bindings for the Python environment.
* @param ruleNames the set of names of all rules in the build language.
* @throws IOException if there was an I/O problem preparing for preprocessing.
* @return a pair of the ParserInputSource and a map of subincludes seen during the evaluation
*/
Result preprocess(
ParserInputSource in,
String packageName,
Globber globber,
Environment.Frame globals,
Set<String> ruleNames)
throws IOException, InterruptedException;
}
|
