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Issue 891673003: dart2js: Refactoring, documentation, and a few bugfixes in Namer class. (Closed) Base URL: https://dart.googlecode.com/svn/branches/bleeding_edge/dart
Patch Set: Comments & some fixes Created 5 years, 10 months ago
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1 // Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file 1 // Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file
2 // for details. All rights reserved. Use of this source code is governed by a 2 // for details. All rights reserved. Use of this source code is governed by a
3 // BSD-style license that can be found in the LICENSE file. 3 // BSD-style license that can be found in the LICENSE file.
4 4
5 part of js_backend; 5 part of js_backend;
6 6
7 /** 7 /**
8 * Assigns JavaScript identifiers to Dart variables, class-names and members. 8 * Assigns JavaScript identifiers to Dart variables, class-names and members.
9 */ 9 */
10 class MinifyNamer extends Namer { 10 class MinifyNamer extends Namer {
(...skipping 13 matching lines...) Expand all
24 final ALPHABET_CHARACTERS = 52; // a-zA-Z. 24 final ALPHABET_CHARACTERS = 52; // a-zA-Z.
25 final ALPHANUMERIC_CHARACTERS = 62; // a-zA-Z0-9. 25 final ALPHANUMERIC_CHARACTERS = 62; // a-zA-Z0-9.
26 26
27 _FieldNamingRegistry fieldRegistry; 27 _FieldNamingRegistry fieldRegistry;
28 28
29 // You can pass an invalid identifier to this and unlike its non-minifying 29 // You can pass an invalid identifier to this and unlike its non-minifying
30 // counterpart it will never return the proposedName as the new fresh name. 30 // counterpart it will never return the proposedName as the new fresh name.
31 String getFreshName(String proposedName, 31 String getFreshName(String proposedName,
32 Set<String> usedNames, 32 Set<String> usedNames,
33 Map<String, String> suggestedNames, 33 Map<String, String> suggestedNames,
34 {bool ensureSafe: true}) { 34 {bool sanitizeForNatives, bool sanitizeForAnnotations}) {
floitsch 2015/02/06 12:59:55 Add comment that sanitizeForNatives/sanitizeForAnn
asgerf 2015/02/06 13:27:06 Done.
35 var freshName; 35 String freshName;
36 var suggestion = suggestedNames[proposedName]; 36 String suggestion = suggestedNames[proposedName];
37 if (suggestion != null && !usedNames.contains(suggestion)) { 37 if (suggestion != null && !usedNames.contains(suggestion)) {
38 freshName = suggestion; 38 freshName = suggestion;
39 } else { 39 } else {
40 freshName = _getUnusedName(proposedName, usedNames, 40 freshName = _getUnusedName(proposedName, usedNames,
41 suggestedNames.values); 41 suggestedNames.values);
42 } 42 }
43 usedNames.add(freshName); 43 usedNames.add(freshName);
44 return freshName; 44 return freshName;
45 } 45 }
46 46
47 String getClosureVariableName(String name, int id) { 47 String getClosureVariableName(String _, int id) {
48 if (id < ALPHABET_CHARACTERS) { 48 if (id < ALPHABET_CHARACTERS) {
49 return new String.fromCharCodes([_letterNumber(id)]); 49 return new String.fromCharCodes([_letterNumber(id)]);
50 } 50 }
51 return "${getMappedInstanceName('closure')}_$id"; 51 // Fall back to a slightly longer name.
52 String basename = _disambiguateMember(null, 'closure');
53 return '${basename}_$id';
52 } 54 }
53 55
54 // From issue 7554. These should not be used on objects (as instance 56 // From issue 7554. These should not be used on objects (as instance
55 // variables) because they clash with names from the DOM. However, it is 57 // variables) because they clash with names from the DOM. However, it is
56 // OK to use them as fields, as we only access fields directly if we know 58 // OK to use them as fields, as we only access fields directly if we know
57 // the receiver type. 59 // the receiver type.
58 static const _reservedNativeProperties = const <String>[ 60 static const List<String> _reservedNativeProperties = const <String>[
59 'Q', 'a', 'b', 'c', 'd', 'e', 'f', 'r', 'x', 'y', 'z', 61 'Q', 'a', 'b', 'c', 'd', 'e', 'f', 'r', 'x', 'y', 'z',
60 // 2-letter: 62 // 2-letter:
61 'ch', 'cx', 'cy', 'db', 'dx', 'dy', 'fr', 'fx', 'fy', 'go', 'id', 'k1', 63 'ch', 'cx', 'cy', 'db', 'dx', 'dy', 'fr', 'fx', 'fy', 'go', 'id', 'k1',
62 'k2', 'k3', 'k4', 'r1', 'r2', 'rx', 'ry', 'x1', 'x2', 'y1', 'y2', 64 'k2', 'k3', 'k4', 'r1', 'r2', 'rx', 'ry', 'x1', 'x2', 'y1', 'y2',
63 // 3-letter: 65 // 3-letter:
64 'add', 'all', 'alt', 'arc', 'CCW', 'cmp', 'dir', 'end', 'get', 'in1', 66 'add', 'all', 'alt', 'arc', 'CCW', 'cmp', 'dir', 'end', 'get', 'in1',
65 'in2', 'INT', 'key', 'log', 'low', 'm11', 'm12', 'm13', 'm14', 'm21', 67 'in2', 'INT', 'key', 'log', 'low', 'm11', 'm12', 'm13', 'm14', 'm21',
66 'm22', 'm23', 'm24', 'm31', 'm32', 'm33', 'm34', 'm41', 'm42', 'm43', 68 'm22', 'm23', 'm24', 'm31', 'm32', 'm33', 'm34', 'm41', 'm42', 'm43',
67 'm44', 'max', 'min', 'now', 'ONE', 'put', 'red', 'rel', 'rev', 'RGB', 69 'm44', 'max', 'min', 'now', 'ONE', 'put', 'red', 'rel', 'rev', 'RGB',
68 'sdp', 'set', 'src', 'tag', 'top', 'uid', 'uri', 'url', 'URL', 70 'sdp', 'set', 'src', 'tag', 'top', 'uid', 'uri', 'url', 'URL',
69 // 4-letter: 71 // 4-letter:
70 'abbr', 'atob', 'Attr', 'axes', 'axis', 'back', 'BACK', 'beta', 'bias', 72 'abbr', 'atob', 'Attr', 'axes', 'axis', 'back', 'BACK', 'beta', 'bias',
71 'Blob', 'blue', 'blur', 'BLUR', 'body', 'BOOL', 'BOTH', 'btoa', 'BYTE', 73 'Blob', 'blue', 'blur', 'BLUR', 'body', 'BOOL', 'BOTH', 'btoa', 'BYTE',
72 'cite', 'clip', 'code', 'cols', 'cues', 'data', 'DECR', 'DONE', 'face', 74 'cite', 'clip', 'code', 'cols', 'cues', 'data', 'DECR', 'DONE', 'face',
73 'file', 'File', 'fill', 'find', 'font', 'form', 'gain', 'hash', 'head', 75 'file', 'File', 'fill', 'find', 'font', 'form', 'gain', 'hash', 'head',
74 'high', 'hint', 'host', 'href', 'HRTF', 'IDLE', 'INCR', 'info', 'INIT', 76 'high', 'hint', 'host', 'href', 'HRTF', 'IDLE', 'INCR', 'info', 'INIT',
75 'isId', 'item', 'KEEP', 'kind', 'knee', 'lang', 'left', 'LESS', 'line', 77 'isId', 'item', 'KEEP', 'kind', 'knee', 'lang', 'left', 'LESS', 'line',
76 'link', 'list', 'load', 'loop', 'mode', 'name', 'Node', 'None', 'NONE', 78 'link', 'list', 'load', 'loop', 'mode', 'name', 'Node', 'None', 'NONE',
77 'only', 'open', 'OPEN', 'ping', 'play', 'port', 'rect', 'Rect', 'refX', 79 'only', 'open', 'OPEN', 'ping', 'play', 'port', 'rect', 'Rect', 'refX',
78 'refY', 'RGBA', 'root', 'rows', 'save', 'seed', 'seek', 'self', 'send', 80 'refY', 'RGBA', 'root', 'rows', 'save', 'seed', 'seek', 'self', 'send',
79 'show', 'SINE', 'size', 'span', 'stat', 'step', 'stop', 'tags', 'text', 81 'show', 'SINE', 'size', 'span', 'stat', 'step', 'stop', 'tags', 'text',
80 'Text', 'time', 'type', 'view', 'warn', 'wrap', 'ZERO']; 82 'Text', 'time', 'type', 'view', 'warn', 'wrap', 'ZERO'];
81 83
82 void reserveBackendNames() { 84 void reserveBackendNames() {
83 for (var name in _reservedNativeProperties) { 85 for (String name in _reservedNativeProperties) {
84 if (name.length < 2) { 86 if (name.length < 2) {
85 instanceNameMap[name] = name; 87 // Ensure the 1-letter names are disambiguated to the same name.
88 String disambiguatedName = name;
89 reservePublicMemberName(name, disambiguatedName);
86 } 90 }
87 usedInstanceNames.add(name); 91 usedInstanceNames.add(name);
88 // Getter and setter names are autogenerated by prepending 'g' and 's' to 92 // Getter and setter names are autogenerated by prepending 'g' and 's' to
89 // field names. Therefore there are some field names we don't want to 93 // field names. Therefore there are some field names we don't want to
90 // use. It is implicit in the next line that the banned prefix is 94 // use. It is implicit in the next line that the banned prefix is
91 // only one character. 95 // only one character.
92 if (_hasBannedPrefix(name)) usedInstanceNames.add(name.substring(1)); 96 if (_hasBannedPrefix(name)) usedInstanceNames.add(name.substring(1));
93 } 97 }
94 98
95 // These popular names are present in most programs and deserve 99 // These popular names are present in most programs and deserve
(...skipping 63 matching lines...) Expand 10 before | Expand all | Expand 10 after
159 Iterable<String> suggestions) { 163 Iterable<String> suggestions) {
160 int hash = _calculateHash(proposedName); 164 int hash = _calculateHash(proposedName);
161 // Avoid very small hashes that won't try many names. 165 // Avoid very small hashes that won't try many names.
162 hash = hash < 1000 ? hash * 314159 : hash; // Yes, it's prime. 166 hash = hash < 1000 ? hash * 314159 : hash; // Yes, it's prime.
163 167
164 // Try other n-character names based on the hash. We try one to three 168 // Try other n-character names based on the hash. We try one to three
165 // character identifiers. For each length we try around 10 different names 169 // character identifiers. For each length we try around 10 different names
166 // in a predictable order determined by the proposed name. This is in order 170 // in a predictable order determined by the proposed name. This is in order
167 // to make the renamer stable: small changes in the input should nornally 171 // to make the renamer stable: small changes in the input should nornally
168 // result in relatively small changes in the output. 172 // result in relatively small changes in the output.
169 for (var n = 1; n <= 3; n++) { 173 for (int n = 1; n <= 3; n++) {
170 int h = hash; 174 int h = hash;
171 while (h > 10) { 175 while (h > 10) {
172 var codes = <int>[_letterNumber(h)]; 176 List<int> codes = <int>[_letterNumber(h)];
173 int h2 = h ~/ ALPHABET_CHARACTERS; 177 int h2 = h ~/ ALPHABET_CHARACTERS;
174 for (var i = 1; i < n; i++) { 178 for (int i = 1; i < n; i++) {
175 codes.add(_alphaNumericNumber(h2)); 179 codes.add(_alphaNumericNumber(h2));
176 h2 ~/= ALPHANUMERIC_CHARACTERS; 180 h2 ~/= ALPHANUMERIC_CHARACTERS;
177 } 181 }
178 final candidate = new String.fromCharCodes(codes); 182 final candidate = new String.fromCharCodes(codes);
179 if (!usedNames.contains(candidate) && 183 if (!usedNames.contains(candidate) &&
180 !jsReserved.contains(candidate) && 184 !jsReserved.contains(candidate) &&
181 !_hasBannedPrefix(candidate) && 185 !_hasBannedPrefix(candidate) &&
182 (n != 1 || !suggestions.contains(candidate))) { 186 (n != 1 || !suggestions.contains(candidate))) {
183 return candidate; 187 return candidate;
184 } 188 }
(...skipping 21 matching lines...) Expand all
206 h &= 0xffffffff; 210 h &= 0xffffffff;
207 h ^= h >> 6; 211 h ^= h >> 6;
208 h &= 0xffffffff; 212 h &= 0xffffffff;
209 } 213 }
210 return h; 214 return h;
211 } 215 }
212 216
213 /// If we can't find a hash based name in the three-letter space, then base 217 /// If we can't find a hash based name in the three-letter space, then base
214 /// the name on a letter and a counter. 218 /// the name on a letter and a counter.
215 String _badName(int hash, Set<String> usedNames) { 219 String _badName(int hash, Set<String> usedNames) {
216 var startLetter = new String.fromCharCodes([_letterNumber(hash)]); 220 String startLetter = new String.fromCharCodes([_letterNumber(hash)]);
217 var name; 221 String name;
218 var i = 0; 222 int i = 0;
219 do { 223 do {
220 name = "$startLetter${i++}"; 224 name = "$startLetter${i++}";
221 } while (usedNames.contains(name)); 225 } while (usedNames.contains(name));
222 // We don't need to check for banned prefix because the name is in the form 226 // We don't need to check for banned prefix because the name is in the form
223 // xnnn, where nnn is a number. There can be no getter or setter called 227 // xnnn, where nnn is a number. There can be no getter or setter called
224 // gnnn since that would imply a numeric field name. 228 // gnnn since that would imply a numeric field name.
225 return name; 229 return name;
226 } 230 }
227 231
228 int _letterNumber(int x) { 232 int _letterNumber(int x) {
(...skipping 55 matching lines...) Expand 10 before | Expand all | Expand 10 after
284 if (count >= nameStore.length) { 288 if (count >= nameStore.length) {
285 // The namer usually does not use certain names as they clash with 289 // The namer usually does not use certain names as they clash with
286 // existing properties on JS objects (see [_reservedNativeProperties]). 290 // existing properties on JS objects (see [_reservedNativeProperties]).
287 // However, some of them are really short and safe to use for fields. 291 // However, some of them are really short and safe to use for fields.
288 // Thus, we shortcut the namer to use those first. 292 // Thus, we shortcut the namer to use those first.
289 if (count < MinifyNamer._reservedNativeProperties.length && 293 if (count < MinifyNamer._reservedNativeProperties.length &&
290 MinifyNamer._reservedNativeProperties[count].length <= 2) { 294 MinifyNamer._reservedNativeProperties[count].length <= 2) {
291 nameStore.add(MinifyNamer._reservedNativeProperties[count]); 295 nameStore.add(MinifyNamer._reservedNativeProperties[count]);
292 } else { 296 } else {
293 nameStore.add(namer.getFreshName("field$count", 297 nameStore.add(namer.getFreshName("field$count",
294 namer.usedInstanceNames, namer.suggestedInstanceNames, 298 namer.usedInstanceNames, namer.suggestedInstanceNames));
295 ensureSafe: true));
296 } 299 }
297 } 300 }
298 301
299 return nameStore[count]; 302 return nameStore[count];
300 } 303 }
301 } 304 }
302 305
303 /** 306 /**
304 * A [_FieldNamingScope] encodes a node in the inheritance tree of the current 307 * A [_FieldNamingScope] encodes a node in the inheritance tree of the current
305 * class hierarchy. The root node typically is the node corresponding to the 308 * class hierarchy. The root node typically is the node corresponding to the
(...skipping 109 matching lines...) Expand 10 before | Expand all | Expand 10 after
415 Map<Entity, String> get names => registry.globalNames; 418 Map<Entity, String> get names => registry.globalNames;
416 419
417 _MixinFieldNamingScope.mixin(ClassElement cls, _FieldNamingRegistry registry) 420 _MixinFieldNamingScope.mixin(ClassElement cls, _FieldNamingRegistry registry)
418 : super.rootScope(cls, registry); 421 : super.rootScope(cls, registry);
419 422
420 _MixinFieldNamingScope.mixedIn(MixinApplicationElement container, 423 _MixinFieldNamingScope.mixedIn(MixinApplicationElement container,
421 _FieldNamingScope superScope, _FieldNamingRegistry registry) 424 _FieldNamingScope superScope, _FieldNamingRegistry registry)
422 : super.inherit(container, superScope, registry); 425 : super.inherit(container, superScope, registry);
423 426
424 String _nextName() { 427 String _nextName() {
425 var proposed = super._nextName(); 428 String proposed = super._nextName();
426 return proposed + r'$'; 429 return proposed + r'$';
427 } 430 }
428 } 431 }
429 432
430 /** 433 /**
431 * [BoxFieldElement] fields work differently in that they do not belong to an 434 * [BoxFieldElement] fields work differently in that they do not belong to an
432 * actual class but an anonymous box associated to a [Local]. As there is no 435 * actual class but an anonymous box associated to a [Local]. As there is no
433 * inheritance chain, we do not need to compute fields a priori but can assign 436 * inheritance chain, we do not need to compute fields a priori but can assign
434 * names on the fly. 437 * names on the fly.
435 */ 438 */
436 class _BoxFieldNamingScope extends _FieldNamingScope { 439 class _BoxFieldNamingScope extends _FieldNamingScope {
437 _BoxFieldNamingScope(Local box, _FieldNamingRegistry registry) : 440 _BoxFieldNamingScope(Local box, _FieldNamingRegistry registry) :
438 super.rootScope(box, registry); 441 super.rootScope(box, registry);
439 442
440 bool containsField(_) => true; 443 bool containsField(_) => true;
441 444
442 String operator[](Element field) { 445 String operator[](Element field) {
443 if (!names.containsKey(field)) add(field); 446 if (!names.containsKey(field)) add(field);
444 return names[field]; 447 return names[field];
445 } 448 }
446 } 449 }
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