This repository has been archived by the owner on Nov 25, 2022. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 5
/
EvalFunctionsAtTopScope.java
157 lines (135 loc) · 4.72 KB
/
EvalFunctionsAtTopScope.java
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
/*
* Copyright 2009 Google Inc.
*
* 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.gwt.dev.js;
import com.google.gwt.dev.jjs.impl.JavaToJavaScriptMap;
import com.google.gwt.dev.js.ast.JsBlock;
import com.google.gwt.dev.js.ast.JsContext;
import com.google.gwt.dev.js.ast.JsExprStmt;
import com.google.gwt.dev.js.ast.JsFunction;
import com.google.gwt.dev.js.ast.JsModVisitor;
import com.google.gwt.dev.js.ast.JsProgram;
import com.google.gwt.dev.js.ast.JsProgramFragment;
import com.google.gwt.dev.js.ast.JsStatement;
import java.util.HashSet;
import java.util.ListIterator;
import java.util.Set;
import java.util.Stack;
/**
* Force all functions to be evaluated at the top of the lexical scope in which
* they reside. This makes {@link StaticEvalVisitor} simpler in that we no
* longer have to worry about function declarations within expressions. After
* this runs, only statements can contain declarations. Moved functions will end
* up just before the statement in which they presently reside.
*/
public class EvalFunctionsAtTopScope extends JsModVisitor {
public static void exec(JsProgram jsProgram, JavaToJavaScriptMap map) {
EvalFunctionsAtTopScope fev = new EvalFunctionsAtTopScope(map);
fev.accept(jsProgram);
}
private JsStatement currentStatement;
private final Set<JsFunction> dontMove = new HashSet<JsFunction>();
private final Stack<ListIterator<JsStatement>> itrStack = new Stack<ListIterator<JsStatement>>();
private JavaToJavaScriptMap java2jsMap;
private final Stack<JsBlock> scopeStack = new Stack<JsBlock>();
public EvalFunctionsAtTopScope(JavaToJavaScriptMap java2jsMap) {
this.java2jsMap = java2jsMap;
}
@Override
public void endVisit(JsExprStmt x, JsContext ctx) {
currentStatement = null;
}
@Override
public void endVisit(JsFunction x, JsContext ctx) {
scopeStack.pop();
}
@Override
public void endVisit(JsProgram x, JsContext ctx) {
scopeStack.pop();
}
@Override
public void endVisit(JsProgramFragment x, JsContext ctx) {
scopeStack.pop();
}
@Override
public boolean visit(JsBlock x, JsContext ctx) {
if (x == scopeStack.peek()) {
ListIterator<JsStatement> itr = x.getStatements().listIterator();
itrStack.push(itr);
while (itr.hasNext()) {
JsStatement stmt = itr.next();
JsFunction func = JsStaticEval.isFunctionDecl(stmt);
// Already at the top level.
if (func != null) {
dontMove.add(func);
}
accept(stmt);
if (func != null) {
dontMove.remove(func);
}
}
itrStack.pop();
// Already visited.
return false;
} else {
// Just do normal visitation.
return true;
}
}
@Override
public boolean visit(JsExprStmt x, JsContext ctx) {
currentStatement = x;
return true;
}
@Override
public boolean visit(JsFunction x, JsContext ctx) {
JsStaticEval.isFunctionDecl(currentStatement);
/*
* We do this during visit() to preserve first-to-last evaluation order. We
* check if this function is a vtable declaration and don't move functions
* used in other expressions or are in vtable assignments.
*/
if (x.getName() != null && !dontMove.contains(x)
&& !isVtableDeclaration(currentStatement)) {
/*
* Reinsert this function into the statement immediately before the
* current statement. The current statement will have already been
* returned from the current iterator's next(), so we have to backshuffle
* one step to get in front of it.
*/
ListIterator<JsStatement> itr = itrStack.peek();
itr.previous();
itr.add(x.makeStmt());
itr.next();
ctx.replaceMe(x.getName().makeRef(x.getSourceInfo().makeChild()));
}
// Dive into the function itself.
scopeStack.push(x.getBody());
return true;
}
@Override
public boolean visit(JsProgram x, JsContext ctx) {
scopeStack.push(x.getGlobalBlock());
return true;
}
@Override
public boolean visit(JsProgramFragment x, JsContext ctx) {
scopeStack.push(x.getGlobalBlock());
return true;
}
private boolean isVtableDeclaration(JsStatement currentStatement) {
return java2jsMap.vtableInitToMethod(currentStatement) != null;
}
}