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
|
// 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.syntax;
import static com.google.devtools.build.lib.syntax.compiler.ByteCodeUtils.append;
import com.google.common.collect.ImmutableList;
import com.google.devtools.build.lib.events.Location;
import com.google.devtools.build.lib.syntax.SkylarkList.MutableList;
import com.google.devtools.build.lib.syntax.SkylarkList.Tuple;
import com.google.devtools.build.lib.syntax.compiler.ByteCodeMethodCalls;
import com.google.devtools.build.lib.syntax.compiler.ByteCodeUtils;
import com.google.devtools.build.lib.syntax.compiler.DebugInfo;
import com.google.devtools.build.lib.syntax.compiler.DebugInfo.AstAccessors;
import com.google.devtools.build.lib.syntax.compiler.NewObject;
import com.google.devtools.build.lib.syntax.compiler.VariableScope;
import com.google.devtools.build.lib.util.Preconditions;
import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
import net.bytebuddy.implementation.bytecode.Duplication;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* Syntax node for list and tuple literals.
*
* <p>(Note that during evaluation, both list and tuple values are represented by
* java.util.List objects, the only difference between them being whether or not
* they are mutable.)
*/
public final class ListLiteral extends Expression {
/**
* Types of the ListLiteral.
*/
public static enum Kind {LIST, TUPLE}
private final Kind kind;
private final List<Expression> exprs;
private ListLiteral(Kind kind, List<Expression> exprs) {
this.kind = kind;
this.exprs = exprs;
}
public static ListLiteral makeList(List<Expression> exprs) {
return new ListLiteral(Kind.LIST, exprs);
}
public static ListLiteral makeTuple(List<Expression> exprs) {
return new ListLiteral(Kind.TUPLE, exprs);
}
/** A new literal for an empty list, onto which a new location can be specified */
public static ListLiteral emptyList() {
return makeList(Collections.<Expression>emptyList());
}
/**
* Returns the list of expressions for each element of the tuple.
*/
public List<Expression> getElements() {
return exprs;
}
/**
* Returns true if this list is a tuple (a hash table, immutable list).
*/
public boolean isTuple() {
return kind == Kind.TUPLE;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
Printer.printList(sb, exprs, isTuple(), '"', Printer.SUGGESTED_CRITICAL_LIST_ELEMENTS_COUNT,
Printer.SUGGESTED_CRITICAL_LIST_ELEMENTS_STRING_LENGTH);
return sb.toString();
}
@Override
Object doEval(Environment env) throws EvalException, InterruptedException {
List<Object> result = new ArrayList<>();
for (Expression expr : exprs) {
// Convert NPEs to EvalExceptions.
if (expr == null) {
throw new EvalException(getLocation(), "null expression in " + this);
}
result.add(expr.eval(env));
}
return isTuple() ? Tuple.copyOf(result) : new MutableList(result, env);
}
@Override
public void accept(SyntaxTreeVisitor visitor) {
visitor.visit(this);
}
@Override
void validate(ValidationEnvironment env) throws EvalException {
for (Expression expr : exprs) {
expr.validate(env);
}
}
@Override
ByteCodeAppender compile(VariableScope scope, DebugInfo debugInfo) throws EvalException {
AstAccessors debugAccessors = debugInfo.add(this);
List<ByteCodeAppender> listConstruction = new ArrayList<>();
if (isTuple()) {
append(listConstruction, ByteCodeMethodCalls.BCImmutableList.builder);
} else {
append(
listConstruction,
// create a new MutableList object
NewObject.fromConstructor(MutableList.class, Mutability.class)
.arguments(
scope.loadEnvironment(), ByteCodeUtils.invoke(Environment.class, "mutability")));
}
for (Expression expression : exprs) {
Preconditions.checkNotNull(
expression, "List literal at %s contains null expression", getLocation());
ByteCodeAppender compiledValue = expression.compile(scope, debugInfo);
if (isTuple()) {
listConstruction.add(compiledValue);
append(
listConstruction,
// this re-adds the builder to the stack and we reuse it in the next iteration/after
ByteCodeMethodCalls.BCImmutableList.Builder.add);
} else {
// duplicate the list reference on the stack for reuse in the next iteration/after
append(listConstruction, Duplication.SINGLE);
listConstruction.add(compiledValue);
append(
listConstruction,
debugAccessors.loadLocation,
scope.loadEnvironment(),
ByteCodeUtils.cleanInvoke(
MutableList.class, "add", Object.class, Location.class, Environment.class));
}
}
if (isTuple()) {
append(
listConstruction,
ByteCodeMethodCalls.BCImmutableList.Builder.build,
ByteCodeUtils.invoke(Tuple.class, "create", ImmutableList.class));
}
return ByteCodeUtils.compoundAppender(listConstruction);
}
}
|
